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Sample records for sea level measurements

  1. Precise mean sea level measurements using the Global Positioning System

    NASA Technical Reports Server (NTRS)

    Kelecy, Thomas M.; Born, George H.; Parke, Michael E.; Rocken, Christian

    1994-01-01

    This paper describes the results of a sea level measurement test conducted off La Jolla, California, in November of 1991. The purpose of this test was to determine accurate sea level measurements using a Global Positioning System (GPS) equipped buoy. These measurements were intended to be used as the sea level component for calibration of the ERS 1 satellite altimeter. Measurements were collected on November 25 and 28 when the ERS 1 satellite overflew the calibration area. Two different types of buoys were used. A waverider design was used on November 25 and a spar design on November 28. This provided the opportunity to examine how dynamic effects of the measurement platform might affect the sea level accuracy. The two buoys were deployed at locations approximately 1.2 km apart and about 15 km west of a reference GPS receiver located on the rooftop of the Institute of Geophysics and Planetary Physics at the Scripps Institute of Oceanography. GPS solutions were computed for 45 minutes on each day and used to produce two sea level time series. An estimate of the mean sea level at both locations was computed by subtracting tide gage data collected at the Scripps Pier from the GPS-determined sea level measurements and then filtering out the high-frequency components due to waves and buoy dynamics. In both cases the GPS estimate differed from Rapp's mean altimetric surface by 0.06 m. Thus, the gradient in the GPS measurements matched the gradient in Rapp's surface. These results suggest that accurate sea level can be determined using GPS on widely differing platforms as long as care is taken to determine the height of the GPS antenna phase center above water level. Application areas include measurement of absolute sea level, of temporal variations in sea level, and of sea level gradients (dominantly the geoid). Specific applications would include ocean altimeter calibration, monitoring of sea level in remote regions, and regional experiments requiring spatial and

  2. Accurate measurement of mean sea level changes by altimetric satellites

    NASA Technical Reports Server (NTRS)

    Born, G. H.; Tapley, B. D.; Ries, J. C.; Stewart, R. H.

    1986-01-01

    A technique for monitoring changes in global mean sea levels using altimeter data from a well-tracked satellite is examined. The usefulness of this technique is evaluated by analyzing Seasat altimeter data obtained during July-September 1978. The effects of orbit errors, geoid errors, sampling intervals, tides, and atmosphere refraction on the calculation of the mean sea level are investigated. The data reveal that the stability of an altimeter can be determined with an accuracy of + or - 7 cm using globally averaged sea surface height measurements. The application of this procedure to the US/French Ocean Topography Experiment is discussed.

  3. Sea Level Rise and Decadal Variations in the Ligurian Sea Inferred from the Medimaremetre Measurements.

    NASA Astrophysics Data System (ADS)

    Karpytchev, M.; Coulomb, A.; Vallee, M.

    2015-12-01

    Estimations of sea level rise over the last centuries are mostly based on the rare historical sea level records from tide gauge stations usually designed for navigational purposes. In this study, we examine the quality of sea level measurements performed by a mean sea level gauge operated in Nice from 1887 to 1909 and transferred to the nearby town of Villefranche-sur-Mer in 1913 where it stayed in operation untill 1974. The mean sea level gauges, called medimaremetres, were invented for geodetic studies and installed in many French ports since the end of the XIX century. By construction, the medimaremetre was connected to the sea through a porous porcelain crucible in order to filter out the tides and higher frequency sea level oscillations. Ucontrolled properties of the crucible and some systematic errors made the medimaremetre data to be ignored in the current sea level researches. We demonstrate that the Nice-Villefranche medimaremetre measurements are coherent with two available historical tide gauge records from Marseille and Genova and a new century-scale sea level series can be build up by combining the medimaremetre data with the those recorded by a tide gauge operating in Nice since the 1980s. We analyse the low frequency variabilities in Marseille, Nice-Villefranche and Genova and get new insights on the decadal sea level variations in the Ligurian Sea since the end of the XIX century.

  4. Sea level: measuring the bounding surfaces of the ocean

    PubMed Central

    Tamisiea, Mark E.; Hughes, Chris W.; Williams, Simon D. P.; Bingley, Richard M.

    2014-01-01

    The practical need to understand sea level along the coasts, such as for safe navigation given the spatially variable tides, has resulted in tide gauge observations having the distinction of being some of the longest instrumental ocean records. Archives of these records, along with geological constraints, have allowed us to identify the century-scale rise in global sea level. Additional data sources, particularly satellite altimetry missions, have helped us to better identify the rates and causes of sea-level rise and the mechanisms leading to spatial variability in the observed rates. Analysis of all of the data reveals the need for long-term and stable observation systems to assess accurately the regional changes as well as to improve our ability to estimate future changes in sea level. While information from many scientific disciplines is needed to understand sea-level change, this review focuses on contributions from geodesy and the role of the ocean's bounding surfaces: the sea surface and the Earth's crust. PMID:25157196

  5. Sea level: measuring the bounding surfaces of the ocean.

    PubMed

    Tamisiea, Mark E; Hughes, Chris W; Williams, Simon D P; Bingley, Richard M

    2014-09-28

    The practical need to understand sea level along the coasts, such as for safe navigation given the spatially variable tides, has resulted in tide gauge observations having the distinction of being some of the longest instrumental ocean records. Archives of these records, along with geological constraints, have allowed us to identify the century-scale rise in global sea level. Additional data sources, particularly satellite altimetry missions, have helped us to better identify the rates and causes of sea-level rise and the mechanisms leading to spatial variability in the observed rates. Analysis of all of the data reveals the need for long-term and stable observation systems to assess accurately the regional changes as well as to improve our ability to estimate future changes in sea level. While information from many scientific disciplines is needed to understand sea-level change, this review focuses on contributions from geodesy and the role of the ocean's bounding surfaces: the sea surface and the Earth's crust.

  6. Measuring precise sea level from a buoy using the Global Positioning System

    NASA Technical Reports Server (NTRS)

    Rocken, Christian; Kelecy, Thomas M.; Born, George H.; Young, Larry E.; Purcell, George H., Jr.; Wolf, Susan Kornreich

    1990-01-01

    The feasibility of using the Global Positioning System (GPS) for accurate sea surface positioning was examined. An experiment was conducted on the Scripps pier at La Jolla, California from December 13-15, 1989. A GPS-equipped buoy was deployed about 100 m off the pier. Two fixed reference GPS receivers, located on the pier and about 80 km away on Monument Peak, were used to estimate the relative position of the floater. Kinematic GPS processing software, developed at the National Geodetic Survey, and the Jet Propulsion Laboratory's GPS Infrared Processing System software were used to determine the floater position relative to land-fixing receivers. Calculations were made of sea level and ocean wave spectra from GPS measurements. It is found that the GPS sea level for the short 100 m baseline agrees with the PPT sea level at the 1 cm level and has an rms variation of 5 mm over a period of 4 hours.

  7. Global sea level rise

    SciTech Connect

    Douglas, B.C. )

    1991-04-15

    Published values for the long-term, global mean sea level rise determined from tide gauge records exhibit considerable scatter, from about 1 mm to 3 mm/yr. This disparity is not attributable to instrument error; long-term trends computed at adjacent sites often agree to within a few tenths of a millimeter per year. Instead, the differing estimates of global sea level rise appear to be in large part due to authors' using data from gauges located at convergent tectonic plate boundaries, where changes of land elevation give fictitious sea level trends. In addition, virtually all gauges undergo subsidence or uplift due to postglacial rebound (PGR) from the last deglaciation at a rate comparable to or greater than the secular rise of sea level. Modeling PGR by the ICE-3G model of Tushingham and Peltier (1991) and avoiding tide gauge records in areas of converging tectonic plates produces a highly consistent set of long sea level records. The value for mean sea level rise obtained from a global set of 21 such stations in nine oceanic regions with an average record length of 76 years during the period 1880-1980 is 1.8 mm/yr {plus minus} 0.1. This result provides confidence that carefully selected long tide gauge records measure the same underlying trend of sea level and that many old tide gauge records are of very high quality.

  8. Measurement of Instantaneous Sea Level by L-band Radar Interferometry

    NASA Astrophysics Data System (ADS)

    Kim, S.; Won, J.

    2002-12-01

    The radar interferometric measurement on sea surface has not be considered feasible, but Alsdorf et al. (2000) recently demonstrated that interferometric phases of L-HH SAR were correlated with centimeter-scale changes in the height of water surfaces within flooded vegetation. We present the characteristics of the JERS-1 SAR interferometric phase on seawater around Kaduckdo, Korea, and propose a possible application of SAR to measuring instantaneous relative sea level. Coherent signals, caused by manmade oyster farm structures and comparable to those from land in terms of coherence, were observed. Using 21 interferograms produced from 11 JERS-1 SAR single look complex data sets, the instantaneous sea level changes were estimated for the first time. The absolute sea level changes could not properly be restored by interferometric phases alone because of the discontinuity of phase and the large sea level changes in the area of interest. The wrapped phases are limited to an estimation of -7.6~7.6 cm changes due to uncertainty of sign (up or down). The comparison of the radar measurements with the tide gauge data (OTT-R20) yielded a relatively low correlation coefficient, 0.57. The possible error sources included the tide gauge measurements, which was not on-site measurements but 5 km away from the test site, and phase noise error (1.8 cm). We have overcome the ambiguity problem to some extent by exploiting radar back-scattering intensity. The radar intensity from sea farms was normalized using the statistics of the intensities at seawater and urban land area. The normalized intensity was inversely proportional to the sea level with a correlation coefficient of -0.83. We could thus constrain the number of wrapping counts to one (13 pairs) or two (9 pairs) within 68% confidence interval. When the wrapping count was chosen through the proposed method, the correlation coefficient was improved to be 0.96 with an r.m.s. error of 6.0 cm. The results show a feasibility of

  9. Contemporary sea level rise.

    PubMed

    Cazenave, Anny; Llovel, William

    2010-01-01

    Measuring sea level change and understanding its causes has considerably improved in the recent years, essentially because new in situ and remote sensing observations have become available. Here we report on most recent results on contemporary sea level rise. We first present sea level observations from tide gauges over the twentieth century and from satellite altimetry since the early 1990s. We next discuss the most recent progress made in quantifying the processes causing sea level change on timescales ranging from years to decades, i.e., thermal expansion of the oceans, land ice mass loss, and land water-storage change. We show that for the 1993-2007 time span, the sum of climate-related contributions (2.85 +/- 0.35 mm year(-1)) is only slightly less than altimetry-based sea level rise (3.3 +/- 0.4 mm year(-1)): approximately 30% of the observed rate of rise is due to ocean thermal expansion and approximately 55% results from land ice melt. Recent acceleration in glacier melting and ice mass loss from the ice sheets increases the latter contribution up to 80% for the past five years. We also review the main causes of regional variability in sea level trends: The dominant contribution results from nonuniform changes in ocean thermal expansion.

  10. Sea level measurements from inverse modelling of GNSS SNR data - initial results

    NASA Astrophysics Data System (ADS)

    Strandberg, Joakim; Hobiger, Thomas; Haas, Rüdiger

    2016-04-01

    The idea that sea level measurements could be done passively using available GNSS signals was proposed already over two decades ago. Since then several methods of using GNSS signals for measuring sea level have been proposed, using various degrees of specialized equipment. We present a new method to retrieve sea level from GNSS SNR data that relies upon inverse modelling of the detrended SNR data from a single off-the-shelf geodetic GNSS receiver. This method can simultaneously use SNR data from both GPS and GLONASS, and both L1 and L2 frequencies, in order to improve the performance with respect to prior studies. Results from the GNSS-R installation at the Onsala Space Observatory are presented and the retrieved sea level results are compared with data collected by a co-located pressure mareograph. The new method is found to give an RMS error of 1.8 cm. The results are also compared against previous implementations of GNSS tide gauges and found to have lower RMS than both the earlier SNR algorithm and also the dual receiver, phase delay method. This shows that inverse modelling for sea level retrieval has a potential to increase the precision of GNSS-R tide gauges, without the need for specialized equipment. Furthermore, since the method is based on SNR analysis, it can continue to operate during high winds and large sea roughness, in which the dual-receiver phase delay algorithm fails since the receiver connected to the nadir looking antenna does not succeed to lock on the satellites signals. This leads to a more stable and reliable operation. The ability to simultaneously use SNR data from different GNSS systems is also seen as a factor to increase the performance, further reducing the RMS. Therefore, in the future it is of interest to add further GNSS systems, such as Galileo and BeiDou.

  11. Electromagnetic bias of 36-GHz radar altimeter measurements of MSL. [Mean Sea Level

    NASA Technical Reports Server (NTRS)

    Walsh, E. J.; Hancock, D. W., III; Hines, D. E.; Kenney, J. E.

    1984-01-01

    The data reduction techniques used to determine the magnitude of electromagnetic (EM) bias in radar altimeter measurements of mean sea level (MSL) area described. Particular attention is given to the bias reduction scheme developed specifically for the Surface Contour Radar (SCR) instrument of the Ocean Topography Experiment (TOPEX). The SCR makes it possible to determine the amount of the backscattered power due to EM reflectance per unit area by measuring both the return power and elevation. Variations of backscattered power for different sea states are determined as a function of displacement of the MSL. On the basis of the recent SCR observations from aircraft, a standard error due to EM bias is predicted for MSL measurements performed with a satellite altimeter radar operating at a frequency of 36 GHz. The obtained standard error was 1 percent for regions with waves 1.9-5.5 meters in height.

  12. Understanding Sea Level Changes

    NASA Technical Reports Server (NTRS)

    Chao, Benjamin F.

    2004-01-01

    Today more than 100 million people worldwide live on coastlines within one meter of mean sea level; any short-term or long-term sea level change relative to vertical ground motion is of great societal and economic concern. As palm-environment and historical data have clearly indicated the existence and prevalence of such changes in the past, new scientific information regarding to the nature and causes and a prediction capability are of utmost importance for the future. The 10-20 cm global sea-level rise recorded over the last century has been broadly attributed to two effects: (1) the steric effect (thermal expansion and salinity-density compensation of sea water) following global climate; (2) mass-budget changes due to a number of competing geophysical and hydrological processes in the Earth-atmosphere-hydrosphere-cryosphere system, including water exchange from polar ice sheets and mountain glaciers to the ocean, atmospheric water vapor and land hydrological variations, and anthropogenic effects such as water impoundment in artificial reservoirs and extraction of groundwater, all superimposed on the vertical motions of solid Earth due to tectonics, rebound of the mantle from past and present deglaciation, and other local ground motions. As remote-sensing tools, a number of space geodetic measurements of sea surface topography (e.g., TOPEX/Poseidon, Jason), ice mass (e.g., ICESat), time-variable gravity (e.g. GRACE), and ground motions (SLR, VLBI, GPS, InSAR, Laser altimetry, etc.) become directly relevant. Understanding sea level changes "anywhere, anytime" in a well-defined terrestrial reference frame in terms of climate change and interactions among ice masses, oceans, and the solid Earth, and being able to predict them, emerge as one of the scientific challenges in the Solid Earth Science Working Group (SESWG, 2003) conclusions.

  13. Late Pleistocene Sea Level Stack

    NASA Astrophysics Data System (ADS)

    Spratt, R. M.; Lisiecki, L. E.

    2014-12-01

    Sea level reconstructions have been created using wide variety of proxies and models. The accuracy of individual sea level reconstructions is limited by measurement, noise, local variations in salinity and temperature, and the assumptions particular to each reconstruction. To address these limitations, we have created a sea level stack (average) which increases the signal-to-noise ratio of sea level estimates by combining 5-7 sea level reconstructions over the last 800 kyr. Principal Component analysis (PCA) of seven sea level records from 0-430 kyr ago shows that 82% of the variance in these records is explained by their first principal component (i.e., the stack). Additionally, a stack of just the 5 longer records that extends to 800 kyr closely matches the timing and amplitude of our seven-record mean. We find that the mean sea level estimate for Marine Isotope Stage (MIS) 5e is 0-4 m above modern, and that the standard deviation of individual estimates is 11 m. Mean sea level estimates for MIS 11 are 12-16 m above modern with a standard deviation of 30 m. Due to the large variability between individual reconstructions, our sea level stack may provide more robust sea level estimates than any single technique.

  14. Accuracy Assessment of GPS Buoy Sea Level Measurements for Coastal Applications

    NASA Astrophysics Data System (ADS)

    Chiu, S.; Cheng, K.

    2008-12-01

    The GPS buoy in this study contains a geodetic antenna and a compact floater with the GPS receiver and power supply tethered to a boat. The coastal applications using GPS include monitoring of sea level and its change, calibration of satellite altimeters, hydrological or geophysical parameters modeling, seafloor geodesy, and others. Among these applications, in order to understand the overall data or model quality, it is required to gain the knowledge of position accuracy of GPS buoys or GPS-equipped vessels. Despite different new GPS data processing techniques, e.g., Precise Point Positioning (PPP) and virtual reference station (VRS), that require a prioir information obtained from the a regional GPS network. While the required a prioir information can be implemented on land, it may not be available on the sea. Hence, in this study, the GPS buoy was positioned with respect to a onshore GPS reference station using the traditional double- difference technique. Since the atmosphere starts to decorrelate as the baseline, the distance between the buoy and the reference station, increases, the positioning accuracy consequently decreases. Therefore, this study aims to assess the buoy position accuracy as the baseline increases and in order to quantify the upper limit of sea level measured by the GPS buoy. A GPS buoy campaign was conducted by National Chung Cheng University in An Ping, Taiwan with a 8- hour GPS buoy data collection. In addition, a GPS network contains 4 Continuous GPS (CGPS) stations in Taiwan was established with the goal to enable baselines in different range for buoy data processing. A vector relation from the network was utilized in order to find the correct ambiguities, which were applied to the long-baseline solution to eliminate the position error caused by incorrect ambiguities. After this procedure, a 3.6-cm discrepancy was found in the mean sea level solution between the long (~80 km) and the short (~1.5 km) baselines. The discrepancy between a

  15. Sea level variation

    NASA Technical Reports Server (NTRS)

    Douglas, Bruce C.

    1992-01-01

    Published values for the long-term, global mean sea level rise determined from tide gauge records range from about one to three mm per year. The scatter of the estimates appears to arise largely from the use of data from gauges located at convergent tectonic plate boundaries where changes of land elevation give fictitious sea level trends, and the effects of large interdecadal and longer sea level variations on short (less than 50+ years) or sappy records. In addition, virtually all gauges undergo subsidence or uplift due to isostatic rebound from the last deglaciation at a rate comparable to or greater than the secular rise of sea level. Modeling rebound by the ICE-3G model of Tushingham and Peltier (1990) and avoiding tide gauge records in areas of converging tectonic plates produces a highly consistent set of long sea level records. A global set of 21 such stations in nine oceanic regions with an average record length of 76 years during the period 1880-1980 yields the global sea level rise value 1.8 mm/year +/- 0.1. Greenhouse warming scenarios commonly forecast an additional acceleration of global sea level in the next 5 or 6+ decades in the range 0.1-0.2 mm/yr2. Because of the large power at low frequencies in the sea level spectrum, very long tide gauge records (75 years minimum) have been examined for past apparent sea level acceleration. For the 80-year period 1905-1985, 23 essentially complete tide gauge records in 10 geographic groups are available for analysis. These yielded the apparent global acceleration -0.011 (+/- 0.012) mm/yr2. A larger, less uniform set of 37 records in the same 10 groups with 92 years average length covering the 141 years from 1850-1991 gave 0.001 (+/- 0.008) mm/yr2. Thus there is no evidence for an apparent acceleration in the past 100+ years that is significant either statistically, or in comparison to values associated with global warming. Unfortunately, the large interdecadal fluctuations of sea level severely affect

  16. Sea level change

    SciTech Connect

    Meier, M.F.

    1996-12-31

    The IPCC (Intergovernmental Panel on Climate Change) 1995 Scientific Assessment, Chapter 7. Sea Level Change, presents a modest revision of the similar chapter in the 1990 Assessment. Principal conclusions on observed sea-level change and the principal terms in the sea-level equation (ocean thermal expansion, glaciers, ice sheets, and land hydrology), including our knowledge of the present-day (defined as the 20th Century) components of sea-level rise, and projections of these for the future, are presented here. Some of the interesting glaciological problems which are involved in these studies are discussed in more detail. The emphasis here is on trends over decades to a century, not on shorter variations nor on those of the geologic past. Unfortunately, some of the IPCC projections had not been agreed at the time of writing of this paper, and these projections will not be given here. 15 refs., 2 figs.

  17. Rising Seas: Threat to Coastal Areas, A General Study about the Sea Level Rises on Coastal Areas of Earth, its Consequences and Preventive Measures.

    NASA Astrophysics Data System (ADS)

    Kataria, A.

    2015-12-01

    Scientific research indicates that sea levels worldwide have been rising at a rate of 3 millimeters per year since the early 1990s (IPCC), which is much higher than the previous century. The recent measurements (march 2015; NASA) tells us that the present rise of sea level is 64.4 mm. Most recent satellite measurements and tide gauge readings (NASA) tell us that present rate sea level rise is 3.20 mm per year. A recent study says we can expect the oceans to rise between 2.5 and 6.5 feet (0.8 and 2 meters) by 2100. The two main causes of rising seas are thermal expansion and glacier melting which further corresponds to the root cause of sea level rise: Green House effect. For every degree Celsius that global average temperature rises, we can expect 2.3 meters of sea-level rise sometime over the ensuing 2,000 years. The main consequence of Sea level rise is increase in oceanic acidity as it releases the entrapped carbon dioxide in between the glaciers. The problem goes from bad to worse when we take into consideration that one third of the world population lives in a 60 km range from the coast. In the event of a flood, this massive population would have to move away from the coasts. The main objective of research is to find all the most vulnerable areas, to make people aware about the consequences and to take proper measurements to fight with such natural calamities. The rise in sea level would inevitably cause massive migration like never seen before. Over 25% of the world population could disappear if sea levels continues to rise with same or faster rate as present. The oceans, sea life and life of people at coastal areas will get extremely effected unless there are considerable cuts in the carbon dioxide emissions. What we need to do is just to apply all the methods and measurements in our daily life that can help reduce the green house gases emissions. Also we need to plan that how to prevent all these cities in case of such natural hazards.

  18. Projecting future sea level

    USGS Publications Warehouse

    Cayan, Daniel R.; Bromirski, Peter; Hayhoe, Katharine; Tyree, Mary; Dettinger, Mike; Flick, Reinhard

    2006-01-01

    California’s coastal observations and global model projections indicate that California’s open coast and estuaries will experience increasing sea levels over the next century. Sea level rise has affected much of the coast of California, including the Southern California coast, the Central California open coast, and the San Francisco Bay and upper estuary. These trends, quantified from a small set of California tide gages, have ranged from 10–20 centimeters (cm) (3.9–7.9 inches) per century, quite similar to that estimated for global mean sea level. So far, there is little evidence that the rate of rise has accelerated, and the rate of rise at California tide gages has actually flattened since 1980, but projections suggest substantial sea level rise may occur over the next century. Climate change simulations project a substantial rate of global sea level rise over the next century due to thermal expansion as the oceans warm and runoff from melting land-based snow and ice accelerates. Sea level rise projected from the models increases with the amount of warming. Relative to sea levels in 2000, by the 2070–2099 period, sea level rise projections range from 11–54 cm (4.3–21 in) for simulations following the lower (B1) greenhouse gas (GHG) emissions scenario, from 14–61 cm (5.5–24 in) for the middle-upper (A2) emission scenario, and from 17–72 cm (6.7–28 in) for the highest (A1fi) scenario. In addition to relatively steady secular trends, sea levels along the California coast undergo shorter period variability above or below predicted tide levels and changes associated with long-term trends. These variations are caused by weather events and by seasonal to decadal climate fluctuations over the Pacific Ocean that in turn affect the Pacific coast. Highest coastal sea levels have occurred when winter storms and Pacific climate disturbances, such as El Niño, have coincided with high astronomical tides. This study considers a range of projected future

  19. Caribbean Sea Level Network

    NASA Astrophysics Data System (ADS)

    von Hillebrandt-Andrade, C.; Crespo Jones, H.

    2012-12-01

    Over the past 500 years almost 100 tsunamis have been observed in the Caribbean and Western Atlantic, with at least 3510 people having lost their lives to this hazard since 1842. Furthermore, with the dramatic increase in population and infrastructure along the Caribbean coasts, today, millions of coastal residents, workers and visitors are vulnerable to tsunamis. The UNESCO IOC Intergovernmental Coordination Group for Tsunamis and other Coastal Hazards for the Caribbean and Adjacent Regions (CARIBE EWS) was established in 2005 to coordinate and advance the regional tsunami warning system. The CARIBE EWS focuses on four areas/working groups: (1) Monitoring and Warning, (2) Hazard and Risk Assessment, (3) Communication and (4) Education, Preparedness and Readiness. The sea level monitoring component is under Working Group 1. Although in the current system, it's the seismic data and information that generate the initial tsunami bulletins, it is the data from deep ocean buoys (DARTS) and the coastal sea level gauges that are critical for the actual detection and forecasting of tsunamis impact. Despite multiple efforts and investments in the installation of sea level stations in the region, in 2004 there were only a handful of sea level stations operational in the region (Puerto Rico, US Virgin Islands, Bermuda, Bahamas). Over the past 5 years there has been a steady increase in the number of stations operating in the Caribbean region. As of mid 2012 there were 7 DARTS and 37 coastal gauges with additional ones being installed or funded. In order to reach the goal of 100 operational coastal sea level stations in the Caribbean, the CARIBE EWS recognizes also the importance of maintaining the current stations. For this, a trained workforce in the region for the installation, operation and data analysis and quality control is considered to be critical. Since 2008, three training courses have been offered to the sea level station operators and data analysts. Other

  20. Sea Level Rise in Tuvalu

    NASA Astrophysics Data System (ADS)

    Lin, C. C.; Ho, C. R.; Cheng, Y. H.

    2012-04-01

    Most people, especially for Pacific Islanders, are aware of the sea level change which may caused by many factors, but no of them has deeper sensation of flooding than Tuvaluan. Tuvalu, a coral country, consists of nine low-lying islands in the central Pacific between the latitudes of 5 and 10 degrees south, has the average elevation of 2 meters (South Pacific Sea Level and Climate Monitoring Project, SPSLCMP report, 2006) up to sea level. Meanwhile, the maximum sea level recorded was 3.44m on February 28th 2006 that damaged Tuvaluan's property badly. Local people called the flooding water oozes up out of the ground "King Tide", that happened almost once or twice a year, which destroyed the plant, polluted their fresh water, and forced them to colonize to some other countries. The predictable but uncontrollable king tide had been observed for a long time by SPSLCMP, but some of the uncertainties which intensify the sea level rise need to be analyzed furthermore. In this study, a span of 18 years of tide gauge data accessed from Sea Level Fine Resolution Acoustic Measuring Equipment (SEAFRAME) are compared with the satellite altimeter data accessed from Archiving Validation and Interpretation of Satellite Data in Oceanography (AVISO). All above are processed under the limitation of same time and spatial range. The outcome revealed a 9.26cm difference between both. After the tide gauge data shifted to the same base as altimeter data, the results showed the unknown residuals are always positive under the circumstances of the sea level rise above 3.2m. Apart from uncertainties in observing, the residual reflected unknown contributions. Among the total case number of sea level rise above 3.2m is 23 times, 22 of which were recorded with oceanic warm eddy happened simultaneously. The unknown residual seems precisely matched with oceanic warm eddies and illustrates a clear future approach for Tuvaluan to care for.

  1. North Atlantic Coast of the USA - Sea Level Change Vulnerability and Adaptation Measures

    DTIC Science & Technology

    2014-01-07

    studies 4. In assessing a maximum rate for increased coastal erosion processes  e.g. Calvert Cliffs illustration 5. In situations “where there is...severe storm actions.  Migration is defence against sea level rise, as they can naturally reshape in response to the coastal process changes...replenishment on seaward face, and sediment bypassing around the jetties, has allowed the two halves to be maintained as coastal defences.  encouraging the

  2. Dynamics of sea level variations in the coastal Red Sea

    NASA Astrophysics Data System (ADS)

    Churchill, James; Abulnaja, Yasser; Nellayaputhenpeedika, Mohammedali; Limeburner, Richard; Lentz, Steven

    2016-04-01

    Sea level variations in the central Red Sea coastal zone span a range of roughly 1.2 m. Though relatively small, these water level changes can significantly impact the environment over the shallow reef tops prevalent in the central Red Sea, altering the water depth by a factor or two or more. While considerable scientific work has been directed at tidal and seasonal variations of Red Sea water level, very little attention has been given to elevation changes in an 'intermediate' frequency band, with periods of 2-30 d, even though motions in this band account for roughly half of the sea level variance in central Red Sea. We examined the sea level signal in this band using AVISO sea level anomaly (SLA) data, COARDAS wind data and measurements from pressure sensors maintained for more than five years at a number of locations in Saudi Arabian coastal waters. Empirical orthogonal function analysis of the SLA data indicates that longer-period (10-30 d) sea level variations in the intermediate band are dominated by coherent motions in a single mode that extends over most of the Red Sea axis. Idealized model results indicate that this large-scale mode of sea level motion is principally due to variations in the large-scale gradient of the along-axis wind. Our analysis indicates that coastal sea level motions at shorter periods (2-10 d) are principally generated by a combination of direct forcing by the local wind stress and forcing associated with large-scale wind stress gradients. However, also contributing to coastal sea level variations in the intermediate frequency band are mesoscale eddies, which are prevalent throughout the Red Sea basin, have a sea level signal of 10's of cm and produce relatively small-scale (order 50 km) changes in coastal sea level.

  3. Measuring the level of agreement in hematologic and biochemical values between blood sampling sites in leatherback sea turtles (Dermochelys coriacea).

    PubMed

    Stewart, Kimberly; Mitchell, Mark A; Norton, Terry; Krecek, Rosina C

    2012-12-01

    Conservation programs to protect endangered sea turtles are being instituted worldwide. A common practice in these programs is to collect blood to evaluate the health of the turtles. Several different venipuncture sites are used to collect blood from sea turtles for hematologic and biochemistry tests, depending on the species. To date, it is unknown what affect venipuncture site may have on sample results. The purpose of this study was to measure the level of agreement between hematologic and biochemistry values collected from the dorsal cervical sinus and the interdigital vein of leatherback (Dermochelys coriacea) sea turtles. Paired heparinized blood samples were obtained from the dorsal cervical sinus and the interdigital vein of 12 adult female nesting leatherback sea turtles on Keys Beach, St. Kitts, West Indies. Even though the sample population was small, the data for each chemistry were normally distributed, except for creatine kinase (CK). There was no significant difference when comparing biochemistry or hematologic values by venipuncture site, except for CK (P = 0.02). The level of agreement between sampling sites was considered good for albumin, calcium, globulin, glucose, packed cell volume, phosphorus, potassium, sodium, total protein, total solids, uric acid, white blood cell count, and all of the individual white cell types, while the level of agreement for aspartate aminotransferase and CK were considered poor. This information, coupled with the fact that the interdigital vein affords a less-invasive procedure, demonstrates that the interdigital vein is an appropriate location to use when establishing a hematologic and biochemical profile for leatherback sea turtles.

  4. Analysis of sea level and sea surface temperature changes in the Black Sea

    NASA Astrophysics Data System (ADS)

    Betul Avsar, Nevin; Jin, Shuanggen; Kutoglu, Hakan; Erol, Bihter

    2016-07-01

    The Black Sea is a nearly closed sea with limited interaction with the Mediterranean Sea through the Turkish Straits. Measurement of sea level change will provide constraints on the water mass balance and thermal expansion of seawaters in response to climate change. In this paper, sea level changes in the Black Sea are investigated between January 1993 and December 2014 using multi-mission satellite altimetry data and sea surface temperature (SST) data. Here, the daily Maps of Sea Level Anomaly (MSLA) gridded with a 1/8°x1/8° spatial resolution from AVISO and the NOAA 1/4° daily Optimum Interpolation Sea Surface Temperature (OISST) Anomaly data set are used. The annual cycles of sea level and sea surface temperature changes reach the maximum values in November and January, respectively. The trend is 3.16±0.77 mm/yr for sea level change and -0.06±0.01°C/yr for sea surface temperature during the same 22-year period. The observed sea level rise is highly correlated with sea surface warming for the same time periods. In addition, the geographical distribution of the rates of the Black Sea level and SST changes between January 1993 and December 2014 are further analyzed, showing a good agreement in the eastern Black Sea. The rates of sea level rise and sea surface warming are larger in the eastern part than in the western part except in the northwestern Black Sea. Finally, the temporal correlation between sea level and SST time series are presented based on the Empirical Orthogonal Function (EOF) analysis.

  5. Uncertainties in measuring populations potentially impacted by sea level rise and coastal flooding.

    PubMed

    Mondal, Pinki; Tatem, Andrew J

    2012-01-01

    A better understanding of the impact of global climate change requires information on the locations and characteristics of populations affected. For instance, with global sea level predicted to rise and coastal flooding set to become more frequent and intense, high-resolution spatial population datasets are increasingly being used to estimate the size of vulnerable coastal populations. Many previous studies have undertaken this by quantifying the size of populations residing in low elevation coastal zones using one of two global spatial population datasets available - LandScan and the Global Rural Urban Mapping Project (GRUMP). This has been undertaken without consideration of the effects of this choice, which are a function of the quality of input datasets and differences in methods used to construct each spatial population dataset. Here we calculate estimated low elevation coastal zone resident population sizes from LandScan and GRUMP using previously adopted approaches, and quantify the absolute and relative differences achieved through switching datasets. Our findings suggest that the choice of one particular dataset over another can translate to a difference of more than 7.5 million vulnerable people for countries with extensive coastal populations, such as Indonesia and Japan. Our findings also show variations in estimates of proportions of national populations at risk range from <0.1% to 45% differences when switching between datasets, with large differences predominantly for countries where coarse and outdated input data were used in the construction of the spatial population datasets. The results highlight the need for the construction of spatial population datasets built on accurate, contemporary and detailed census data for use in climate change impact studies and the importance of acknowledging uncertainties inherent in existing spatial population datasets when estimating the demographic impacts of climate change.

  6. Two Sea-Level Challenges

    NASA Astrophysics Data System (ADS)

    Galvin, C.

    2008-12-01

    "No place on the sandy ocean shores of the world has been shown to be eroding because of sea level rise." This statement appeared nearly 19 years ago in bold print at the top of the page in a brief article published in Shore and Beach (Galvin,1990). The term "sea level rise" was defined in 1990 as follows: "In this statement, "sea level rise" has the meaning that the average person on the street usually attaches to that term. That is, sea level is rising; not, as in some places like the Mississippi River delta, land level is sinking." While still a subject of controversy, it is now (2008) increasingly plausible (Tornqvist et al,2008) that damage from Hurricane Katrina was significantly worse on the Mississippi River delta because floodwaters exploited wetlands and levees whose elevations had been lowered by decades of compaction in the underlying soil. (1) "Sea level" commonly appears in the literature as "relative sea level rise", occurring that way in 711 publications between 1980 and 2009 (GeoRef database on 8 Sep 08). "Relative sea level rise" does not appear in the 2005 AGI Glossary. The nearest Glossary term is "relative change in sea level", but that term occurs in only 12 publications between 1980 and 2009. The Glossary defines this term in a sequence stratigraphy sense, which infers that "relative sea level rise" is the sum of bottom subsidence and eustatic sea level rise. In plain English, "relative sea level rise" means "water depth increase". For present day coastal environments, "relative sea level rise" is commonly used where eustatic sea level rise is less than subsidence, that is, where the magnitude of actual sea level rise is smaller than the magnitude of subsidence. In that situation, "relative sea level rise" misleads both the average person and the scientist who is not a coastal geologist. Thus, the first challenge is to abandon "relative sea level rise" in favor of "water depth increase", in order that the words accurately descibe what happens

  7. Contribution of vertical land motions to coastal sea level variations: a global synthesis of multisatellite altimetry, tide gauge and GPS measurements

    NASA Astrophysics Data System (ADS)

    Pfeffer, Julia; Allemand, Pascal

    2016-04-01

    Coastal sea level variations result from a complex mix of climatic, oceanic and geodynamical processes driven by natural and anthropogenic constraints. Combining data from multiple sources is one solution to identify particular processes and progress towards a better understanding of the sea level variations and the assessment of their impacts at coast. Here, we present a global database merging multisatellite altimetry with tide gauges and Global Positioning System (GPS) measurements. Vertical land motions and sea level variations are estimated simultaneously for a network of 886 ground stations with median errors lower than 1 mm/yr. The contribution of vertical land motions to relative sea level variations is explored to better understand the natural hazards associated with sea level rise in coastal areas. Worldwide, vertical land motions dominate 30 % of observed coastal trends. The role of the crust is highly heterogeneous: it can amplify, restrict or counter the effects of climate-induced sea level change. A set of 182 potential vulnerable localities are identified by large coastal subsidence which increases by several times the effects of sea level rise. Though regional behaviours exist, principally caused by GIA (Glacial Isostatic Adjustment), the local variability in vertical land motion prevails. An accurate determination of the vertical motions observed at the coast is fundamental to understand the local processes which contribute to sea level rise, to appraise its impacts on coastal populations and make future predictions.

  8. Long Term Sea Level Change in the Black Sea

    NASA Astrophysics Data System (ADS)

    Cokacar, Tulay; Emin, Özsoy

    2016-04-01

    Since 1992, altimeter missions have dramatically improved our knowledge and understanding of the oceans.This study investigates the long term sea level change during 1992-2015 in the Black Sea. The satellite altimeter data of the Topex-Poseidon, ERS-1 ands ERS-2 missions and sea level variations of 25 tide gauge stations and temperature/salinity data of 25 Argo float observed in the Black Sea are used for the analysis. The altimeter data are assessed and compared with the data from tide gauges and Argo floats in the Black Sea. First ARGO T/S profiles are used to assess the discrepancies observed between the altimeters. Then in situ measurements are compared with multiple altimeter data to detect in situ measurement anomalies and the corrections applied to improve the consistency of the data sets.

  9. Comparison of sea-level measurements between microwave radar and subsurface pressure gauge deployed at select locations along the coast of India

    NASA Astrophysics Data System (ADS)

    Mehra, Prakash; Prabhudesai, Ramachandra Gopal; Joseph, Antony; Kumar, Vijay; Agarvadekar, Yogesh; Luis, Ryan; Nadaf, Lalsab

    2013-01-01

    Sea-level data are obtained from several remote and coastal locations using absolute pressure gauges deployed at known level, known as chart datum. However, to yield correct sea-level measurements from absolute pressure measurements, it is necessary to take into account the atmospheric pressure and water density at the measurement locations. We used data collected from microwave radar and an absolute pressure gauge deployed at Verem, Goa (January 2009 to May 2010), Tuticorin, and Mandapam, Tamil Nadu (June 2010 to March 2011) to carry out comparative studies. The root-mean-square difference between the estimated sea level from radar and pressure gauge (incorporating atmospheric pressure correction) is ˜2.69, 2.73, and 1.46 cm at Verem, Tuticorin, and Mandapam, respectively. Harmonic analysis of the two time-series of sea-level data at Verem produces similar residuals and tidal constituents. Our results indicate the importance of concurrent measurement of atmospheric pressure along with subsurface absolute pressure gauge measurements. Internet-based real-/near-real-time tracking and monitoring of sea level, sea state, and surface-meteorological conditions from a network of several island and coastal stations provides considerable information to disaster managers and local administrators during episodic events such as storms, storm surges, and tsunamis.

  10. Accurately measuring sea level change from space: an ESA Climate Change Initiative for MSL closure budget studies

    NASA Astrophysics Data System (ADS)

    Legeais, JeanFrancois; Cazenave, Anny; Ablain, Michael; Larnicol, Gilles; Benveniste, Jerome; Johannessen, Johnny; Timms, Gary; Andersen, Ole; Cipollini, Paolo; Roca, Monica; Rudenko, Sergei; Fernandes, Joana; Balmaseda, Magdalena; Quartly, Graham; Fenoglio-Marc, Luciana; Meyssignac, Benoit; Scharffenberg, Martin

    2016-04-01

    Sea level is a very sensitive index of climate change and variability. Sea level integrates the ocean warming, mountain glaciers and ice sheet melting. Understanding the sea level variability and changes implies an accurate monitoring of the sea level variable at climate scales, in addition to understanding the ocean variability and the exchanges between ocean, land, cryosphere, and atmosphere. That is why Sea Level is one of the Essential Climate Variables (ECV) selected in the frame of the ESA Climate Change Initiative (CCI) program. It aims at providing long-term monitoring of the sea level ECV with regular updates, as required for climate studies. The program is now in its second phase of 3 year (following phase I during 2011-2013). The objectives are firstly to involve the climate research community, to refine their needs and collect their feedbacks on product quality. And secondly to develop, test and select the best algorithms and standards to generate an updated climate time series and to produce and validate the Sea Level ECV product. This will better answer the climate user needs by improving the quality of the Sea Level products and maintain a sustain service for an up-to-date production. This has led to the production of the Sea Level ECV which has benefited from yearly extensions and now covers the period 1993-2014. We will firstly present the main achievements of the ESA CCI Sea Level Project. On the one hand, the major steps required to produce the 22 years climate time series are briefly described: collect and refine the user requirements, development of adapted algorithms for climate applications and specification of the production system. On the other hand, the product characteristics are described as well as the results from product validation, performed by several groups of the ocean and climate modeling community. At last, new altimeter standards have been developed and the best one have been recently selected in order to produce a full

  11. Accurately measuring sea level change from space: an ESA climate change initiative for MSL closure budget studies

    NASA Astrophysics Data System (ADS)

    Legeais, JeanFrancois; Benveniste, Jérôme

    2016-07-01

    Sea level is a very sensitive index of climate change and variability. Sea level integrates the ocean warming, mountain glaciers and ice sheet melting. Understanding the sea level variability and changes implies an accurate monitoring of the sea level variable at climate scales, in addition to understanding the ocean variability and the exchanges between ocean, land, cryosphere, and atmosphere. That is why Sea Level is one of the Essential Climate Variables (ECV) selected in the frame of the ESA Climate Change Initiative (CCI) program. It aims at providing long-term monitoring of the sea level ECV with regular updates, as required for climate studies. The program is now in its second phase of 3 year (following phase I during 2011-2013). The objectives are firstly to involve the climate research community, to refine their needs and collect their feedbacks on product quality. And secondly to develop, test and select the best algorithms and standards to generate an updated climate time series and to produce and validate the Sea Level ECV product. This will better answer the climate user needs by improving the quality of the Sea Level products and maintain a sustain service for an up-to-date production. This has led to the production of a first version of the Sea Level ECV which has benefited from yearly extensions and now covers the period 1993-2014. Within phase II, new altimeter standards have been developed and tested in order to reprocess the dataset with the best standards for climate studies. The reprocessed ECV will be released in summer 2016. We will present the main achievements of the ESA CCI Sea Level Project. On the one hand, the major steps required to produce the 22 years climate time series are briefly described: collect and refine the user requirements, development of adapted algorithms for climate applications and specification of the production system. On the other hand, the product characteristics are described as well as the results from product

  12. Assimilation of TOPEX Sea Level Measurements with a Reduced-Gravity, Shallow Water Model of the Tropical Pacific Ocean

    NASA Technical Reports Server (NTRS)

    Fukumori, Ichiro

    1995-01-01

    Sea surface height variability measured by TOPEX is analyzed in the tropical Pacific Ocean by way of assimilation into a wind-driven, reduced-gravity, shallow water model using an approximate Kalman filter and smoother. The analysis results in an optimal fit of the dynamic model to the observations, providing it dynamically consistent interpolation of sea level and estimation of the circulation. Nearly 80% of the expected signal variance is accounted for by the model within 20 deg of the equator, and estimation uncertainty is substantially reduced by the voluminous observation. Notable features resolved by the analysis include seasonal changes associated with the North Equatorial Countercurrent and equatorial Kelvin and Rossby waves. Significant discrepancies are also found between the estimate and TOPEX measurements, especially near the eastern boundary. Improvements in the estimate made by the assimilation are validated by comparisons with independent tide gauge and current meter observations. The employed filter and smoother are based on approximately computed estimation error covariance matrices, utilizing a spatial transformation and an symptotic approximation. The analysis demonstrates the practical utility of a quasi-optimal filter and smoother.

  13. Sea level rise and coastal erosion

    NASA Astrophysics Data System (ADS)

    Leatherman, S. P.; Zhang, K.; Douglas, B. C.

    2003-04-01

    One of the most certain consequences of global warming is an increase of global (eustatic) sea level. The resulting inundation from rising seas will heavily impact low-lying areas; at least 100 million persons live within one meter of mean sea level and are at increased risk in the coming decades. The very existence of some island states and deltaic coasts is threatened by sea level rise. An additional threat affecting some of the most heavily developed and economically valuable real estate will come from an exacerbation of sandy beach erosion. As the beach is lost, fixed structures nearby are increasingly exposed to the direct impact of storm waves, and will ultimately be damaged or destroyed unless expensive protective measures are taken. It has long been speculated that the underlying rate of long-term sandy beach erosion is two orders of magnitude greater than the rate of rise of sea level, so that any significant increase of sea level has dire consequences for coastal inhabitants. We present an analysis of a large and consistent database of shoreline positions and sea levels to show that there is an underlying highly multiplicative relation of sandy beach erosion to sea level rise. This result means that the already-severe coastal erosion problems witnessed in the 20th century will be exacerbated in the 21st century under plausible global warming scenarios.

  14. Intermittent sea-level acceleration

    NASA Astrophysics Data System (ADS)

    Olivieri, M.; Spada, G.

    2013-10-01

    Using instrumental observations from the Permanent Service for Mean Sea Level (PSMSL), we provide a new assessment of the global sea-level acceleration for the last ~ 2 centuries (1820-2010). Our results, obtained by a stack of tide gauge time series, confirm the existence of a global sea-level acceleration (GSLA) and, coherently with independent assessments so far, they point to a value close to 0.01 mm/yr2. However, differently from previous studies, we discuss how change points or abrupt inflections in individual sea-level time series have contributed to the GSLA. Our analysis, based on methods borrowed from econometrics, suggests the existence of two distinct driving mechanisms for the GSLA, both involving a minority of tide gauges globally. The first effectively implies a gradual increase in the rate of sea-level rise at individual tide gauges, while the second is manifest through a sequence of catastrophic variations of the sea-level trend. These occurred intermittently since the end of the 19th century and became more frequent during the last four decades.

  15. Future high sea levels in south Sweden

    SciTech Connect

    Blomgren, S.H.; Hanson, H.

    1997-12-31

    An estimation of future mean high water levels in Oeresund and the southwest Baltic Sea is presented together with a discussion of probable consequences for Falsterbo Peninsula, a trumpet-shaped sandy formation of some 25 km{sup 2} size situated in the very southwest corner of Sweden. A literature review coupled with sea-level measurements and observations made in the area every four hours since October 1945 are given and comprise the base for the present analysis.

  16. Superstatistical analysis of sea-level fluctuations

    NASA Astrophysics Data System (ADS)

    Rabassa, Pau; Beck, Christian

    2015-01-01

    We perform a statistical analysis of measured time series of sea levels at various coastal locations in the UK, measured at time differences of 15 min over the past 20 years. When the astronomical tide and other deterministic components are removed from the record, a stochastic signal corresponding to the meteorological component remains, and this is well-described by a superstatistical model. We do various tests on the measured time series, and compare the data at 5 different UK locations. Overall the χ2-superstatistics is best suitable to describe the data, in particular when one looks at the dynamics of sea-level differences on short time scales.

  17. USACE Extreme Sea levels

    DTIC Science & Technology

    2014-03-14

    into Extreme Water Level Characterization 9 September 2013 Attendees: Heidi Moritz, Kate White, Jonathan Simm, Robert Nicholls, Peter Hawkes...adaptation. Robert Nicholls raised the question of how well do we feel that we understand the present extreme climate? We should start with this area...the peer-review and acceptance process for a journal paper. Robert suggested that most of the papers which are needed for an analysis today may be

  18. Development of the Bulgarian Sea Level Service

    NASA Astrophysics Data System (ADS)

    Palazov, Atanas

    2013-04-01

    Systematic sea level measurements have been started in Bulgaria in the beginning of 20th century and nowadays there are 16 coastal sea level stations in operation. Operators of sea level stations are: National Institute of Meteorology and Hydrology, Bulgarian Academy of Sciences (NIMH) - 6 stations, Cadastre Agency, Ministry of Regional Development and Public Works (CA) - 4 stations, Port Infrastructure (PI) - 5 stations and Institute of Oceanology, Bulgarian Academy of Sciences (IO-BAS) - 1 station. Six of them are able to provide real time data. The sea level observations in the network of NIMH, performed at six main Bulgarian ports using standard poles, started in 1910. The program, implemented on the NIMH stations, includes daily measurements of the sea level with water gauges (poles). The position of a zero mark of the water gauge is checked once per year. The sea level network of the CA consists of 4 stations: Varna and Burgas (operational since 1928), Irakly and Ahtopol (since 1971). These stations are equipped with stilling-well tide gauges and with mechanical writing devices which draws sea level changes on paper. A mechanical paper writing instruments were installed in Varna and Burgas during 1928 and in 1971, a new paper writing instruments of type SUM (Russian) were installed in the stations of Irakly and Ahtopol. A set of five sea level stations in the ports of Balchik, Varna west, Pomorie, Burgas and Oil port Burgas was build during 2009 in the frame of Port Operational Marine Observing System (POMOS), equipped with high accuracy microwave instruments and operated by PI. In 2010 a new sea level station was set up in the IO-BAS coastal research base Shkorpolovtci. The station is equipped with high accuracy microwave instrument. These six stations are providing real time data. According to the decision of the Council of Ministers in 2012 sea level stations in Varna, Irakly, Burgas and Ahtopol will be operated jointly by Bulgarian Academy of Sciences and

  19. Tritium level along Romanian Black Sea Coast

    SciTech Connect

    Varlam, C.; Stefanescu, I.; Popescu, I.; Faurescu, I.

    2008-07-15

    Establishing the tritium level along the Romanian Black Sea Coast, after 10 years of exploitation of the nuclear power plant from Cernavoda, is a first step in evaluating its impact on the Black Sea ecosystem. The monitoring program consists of tritium activity concentration measurement in sea water and precipitation from Black Sea Coast between April 2005 and April 2006. The sampling points were spread over the Danube-Black Sea Canal - before the locks Agigea and Navodari, and Black Sea along the coast to the Bulgarian border. The average tritium concentration in sea water collected from the sampling locations had the value of 11.1 {+-} 2.1 TU, close to tritium concentration in precipitation. Although an operating nuclear power plant exists in the monitored area, the values of tritium concentration in two locations are slightly higher than those recorded elsewhere. To conclude, it could be emphasized that until now, Cernavoda NPP did not had any influence on the tritium concentration of the Black Sea Shore. (authors)

  20. Solution notches, earthquakes, and sea level, Haiti

    NASA Astrophysics Data System (ADS)

    Schiffman, C. R.; Mildor, B. S.; Bilham, R. G.

    2010-12-01

    Shortly after the 12 January 2010 Haiti earthquake, we installed an array of five tide gauges to determine sea level and its variability in the region of uplifted corals on the coast SW of Leogane, Haiti, that had been uplift ≤30 cm during the earthquake. Each gauge consists of a pressure transducer bolted 50-80 cm below mean sea level, which samples the difference between atmospheric pressure and sea pressure every 10 minutes. The data are transmitted via the Iridium satellite and are publically available with a latency of 10 minutes to 2 hours. The measurements reveal a maximum tidal range of ≈50 cm with 2-4 week oscillations in mean sea level of several cm. Sea slope, revealed by differences between adjacent gauges, varies 2-5 cm per 10 km at periods of 2-5 weeks, which imposes a disappointing limit to the utility of the gauges in estimating post seismic vertical motions. A parallel study of the form and elevation of coastal notches and mushroom rocks (rocks notched on all sides, hence forming a mushroom shape), along the coast west of Petit Goave suggests that these notches may provide an uplift history of the region over the past several hundreds of years. Notch sections in two areas were contoured, digitized, and compared to mean sea level. The notches mimic the histogram of sea level, suggesting that they are formed by dissolution by acidic surface waters. Notches formed two distinct levels, one approximately 58 cm above mean sea level, and the other approximately 157 cm above mean sea level. Several landslide blocks fell into the sea during the 2010 earthquake, and we anticipate these are destined for conversion to future mushroom rocks. Surfaces have been prepared on these blocks to study the rate of notch formation in situ, and samples are being subjected to acid corrosion in laboratory conditions, with the hope that the depth of notches may provide an estimate of the time of fall of previous rocks to help constrain the earthquake history of this area

  1. Sea Level Variability in the Mediterranean

    NASA Astrophysics Data System (ADS)

    Zerbini, S.; Bruni, S.; del Conte, S.; Errico, M.; Petracca, F.; Prati, C.; Raicich, F.; Santi, E.

    2015-12-01

    Tide gauges measure local sea-level relative to a benchmark on land, therefore the interpretation of these measurements can be limited by the lack of appropriate knowledge of vertical crustal motions. The oldest sea-level records date back to the 18th century; these observations are the only centuries-old data source enabling the estimate of historical sea-level trends/variations. In general, tide gauge benchmarks were not frequently levelled, except in those stations where natural and/or anthropogenic subsidence was a major concern. However, in most cases, it is difficult to retrieve the historical geodetic levelling data. Space geodetic techniques, such as GNSS, Doris and InSAR are now providing measurements on a time and space-continuous basis, giving rise to a large amount of different data sets. The vertical motions resulting from the various analyses need to be compared and best exploited for achieving reliable estimates of sea level variations. In the Mediterranean area, there are a few centennial tide gauge records; our study focuses, in particular, on the Italian time series of Genoa, Marina di Ravenna, Venice and Trieste. Two of these stations, Marina di Ravenna and Venice, are affected by both natural and anthropogenic subsidence, the latter was particularly intense during a few decades of the 20th century because of ground fluids withdrawal. We have retrieved levelling data of benchmarks at and/or close to the tide gauges from the end of 1800 and, for the last couple of decades, also GPS and InSAR height time series in close proximity of the stations. By using an ensemble of these data, modelling of the long-period non-linear behavior of subsidence was successfully accomplished. After removal of the land vertical motions, the linear long period sea-level rates of all stations are in excellent agreement. Over the last two decades, the tide gauge rates were also compared with those obtained by satellite radar altimetry data.

  2. 3000 Years of Sea Level Change.

    NASA Astrophysics Data System (ADS)

    Tanner, William F.

    1992-03-01

    Sea level change is generally taken to indicate climate change, and may be more nearly global than what we perceive to be climate change. Close to the beach, even a small sea level change (such as 1-3 m) produces important changes in local depositional conditions. This effect can be deduced from a study of properly selected beach deposits.Various measures of beach-sand grain size indicate conditions of deposition. The best of these parameters is the kurtosis; it is a reliable indicator of surf-zone wave energy density. An abrupt energy-level shift, after centuries with little change, indicates sea level rise or drop. Kurtosis, within stated limits, shows this.Beach ridge systems (successive, distinct old beach deposits) span the last several thousand years. A sequence of sand samples across such a deposit provides grain-size evidence for alternating high and low sea level. Changes were 1 to 3 m vertically, and took place at rates of about 1 ern yr1. There were at least seven such events in the last 3000 years.The two most recent changes were the drop and subsequent rise that marked the Little Ice Age (starting about 1200 A.D.). One cannot say, from these data, that the planet has come fully out of the Little ice Age. Predictions about what sea level will do in the near future should be based on the many small changes (1 to 3 m) in the last few thousand years, rather than on the arbitrary, fictitious, and unrealistic absolute sea level that appears to underlie various popular forecasts.

  3. Variations in the difference between mean sea level measured either side of Cape Hatteras and their relation to the North Atlantic Oscillation

    NASA Astrophysics Data System (ADS)

    Woodworth, P. L.; Morales Maqueda, M. Á.; Gehrels, W. R.; Roussenov, V. M.; Williams, R. G.; Hughes, C. W.

    2016-11-01

    We consider the extent to which the difference in mean sea level (MSL) measured on the North American Atlantic coast either side of Cape Hatteras varies as a consequence of dynamical changes in the ocean caused by fluctuations in the North Atlantic Oscillation (NAO). From analysis of tide gauge data, we know that changes in MSL-difference and NAO index are correlated on decadal to century timescales enabling a scale factor of MSL-difference change per unit change in NAO index to be estimated. Changes in trend in the NAO index have been small during the past few centuries (when measured using windows of order 60-120 years). Therefore, if the same scale factor applies through this period of time, the corresponding changes in trend in MSL-difference for the past few centuries should also have been small. It is suggested thereby that the sea level records for recent centuries obtained from salt marshes (adjusted for long-term vertical land movements) should have essentially the same NAO-driven trends south and north of Cape Hatteras, only differing due to contributions from other processes such as changes in the Meridional Overturning Circulation or `geophysical fingerprints'. The salt marsh data evidently support this interpretation within their uncertainties for the past few centuries, and perhaps even for the past millennium. Recommendations are made on how greater insight might be obtained by acquiring more measurements and by improved modelling of the sea level response to wind along the shelf.

  4. Sea-Level Projections from the SeaRISE Initiative

    NASA Technical Reports Server (NTRS)

    Nowicki, Sophie; Bindschadler, Robert

    2011-01-01

    SeaRISE (Sea-level Response to Ice Sheet Evolution) is a community organized modeling effort, whose goal is to inform the fifth IPCC of the potential sea-level contribution from the Greenland and Antarctic ice sheets in the 21st and 22nd century. SeaRISE seeks to determine the most likely ice sheet response to imposed climatic forcing by initializing an ensemble of models with common datasets and applying the same forcing to each model. Sensitivity experiments were designed to quantify the sea-level rise associated with a change in: 1) surface mass balance, 2) basal lubrication, and 3) ocean induced basal melt. The range of responses, resulting from the multi-model approach, is interpreted as a proxy of uncertainty in our sea-level projections. http://websrv.cs .umt.edu/isis/index.php/SeaRISE_Assessment.

  5. Late Cretaceous sea level from a paleoshoreline

    SciTech Connect

    McDonough, K.J.; Cross, T.A. )

    1991-04-10

    The contemporary elevation of a Late Cenomanian ({approx}93 Ma) shoreline was determined at five localities along the tectonically stable, eastern margin of the Cretaceous Western Interior Seaway, North America. This shoreline, represented by marine-to-nonmarine facies transitions in strata of the Greenhorn sequence (UZA-2 cycle of Haq et al. (1987)), was identified from outcrop and borehole data. Biostratigraphic zonations constrained the geologic age at each locality. Sequence stratigraphic correlations, based on identifying discrete progradational units and the surfaces that separate them, were used to refine age correlations to better than 100 kyr between localities. A single Cenomanian shoreline was correlated within a single progradational unit, and its elevation was determined at five localities. This paleostrandline occurs 265-286m above present-day sea level, at an average elevation of 276 m. Isostatic and flexural corrections were applied to remove the effects of postdepositional vertical movement, including sediment compaction by loading, uplift due to erosion, and glacial loading and rebound. Errors inherent in each measurement and each correction were estimated. Corrections and their cumulative error estimates yield a Late Cenomanian elevation of 269{plus minus}87 m above present sea level. The corrected elevation approximates sea level at 93 Ma and provides a measure of Late Cenomanian eustasy prior to the Early Turonian highstand. Establishing the absolute value for eustasy at a single point in geologic time provides a frame of reference for calibrating relative sea level curves, as well as constraining the magnitudes of tectonic subsidence, sediment flux, and other variables that controlled water depth and relative sea level.

  6. Sea level trends and interannual variability in the Caribbean Sea

    NASA Astrophysics Data System (ADS)

    Torres, R.; Tsimplis, M.

    2012-04-01

    Sea level trends and interannual variability has been investigated in the Caribbean Sea using altimetry and tide gauge time series from 19 stations. Relative sea level trends range between -2.0 and 10.7 mm/y depending on the length of the available record. Records from stations longer than 40 years converge toward values between 1.2 - 5.2 mm/yr, still a significant range which in some stations is less and in some other significantly larger than the global average. The longest station, Cristobal (102 years) shows a trend of 1.9 mm/yr and, in addition a significant acceleration of 1.6±0.3 mm/y/cy. The observed sea level trends are not affected by the atmospheric pressure effect, within the levels of significance. They are also the same (within the levels of significance) at all seasons. Altimetry shows trends (over 18 years of data) with values up to 5.2 mm/y. In some areas the values are statistically insignificant, but at no areas statistically significant negative values are found. Steric trends from the top 800 m (over the period of altimetric observations) have a basin average trend of 1 mm/y, but it shows large spatial variability with negative trends of -7 mm/y in the Yucatan Basin and positive trends up to 4.9 mm/y in the Venezuela Basin. Decadal trends were found to vary significantly at tide-gauge records as well as altimetric and steric measurements. We further explore the residual interannual variability by comparison with surface wind and climatic indices. This analysis is supported by the Lloyd's Register Trust Fund project Marine Extremes.

  7. The future for the Global Sea Level Observing System (GLOSS) Sea Level Data Rescue

    NASA Astrophysics Data System (ADS)

    Bradshaw, Elizabeth; Matthews, Andrew; Rickards, Lesley; Aarup, Thorkild

    2016-04-01

    Historical sea level data are rare and unrepeatable measurements with a number of applications in climate studies (sea level rise), oceanography (ocean currents, tides, surges), geodesy (national datum), geophysics and geology (coastal land movements) and other disciplines. However, long-term time series are concentrated in the northern hemisphere and there are no records at the Permanent Service for Mean Sea Level (PSMSL) global data bank longer than 100 years in the Arctic, Africa, South America or Antarctica. Data archaeology activities will help fill in the gaps in the global dataset and improve global sea level reconstruction. The Global Sea Level Observing System (GLOSS) is an international programme conducted under the auspices of the WMO-IOC Joint Technical Commission for Oceanography and Marine Meteorology. It was set up in 1985 to collect long-term tide gauge observations and to develop systems and standards "for ocean monitoring and flood warning purposes". At the GLOSS-GE-XIV Meeting in 2015, GLOSS agreed on a number of action items to be developed in the next two years. These were: 1. To explore mareogram digitisation applications, including NUNIEAU (more information available at: http://www.mediterranee.cerema.fr/logiciel-de-numerisation-des-enregistrements-r57.html) and other recent developments in scanning/digitisation software, such as IEDRO's Weather Wizards program, to see if they could be used via a browser. 2. To publicise sea level data archaeology and rescue by: • maintaining and regularly updating the Sea Level Data Archaeology page on the GLOSS website • strengthening links to the GLOSS data centres and data rescue organisations e.g. linking to IEDRO, ACRE, RDA • restarting the sea level data rescue blog with monthly posts. 3. Investigate sources of funding for data archaeology and rescue projects. 4. Propose "Guidelines" for rescuing sea level data. These action items will aid the discovery, scanning, digitising and quality control

  8. CO2 and sea level

    NASA Astrophysics Data System (ADS)

    Bell, Peter M.

    There is considerable discussion currently about the potential effects of carbon dioxide build-up in the atmosphere over the next several decades. The sources of information are two Government funded reports, one by the National Research Council (NRC), the other by the Environment Protection Agency (EPA), both were released within the last five months. The reports were described recently as being conservative, although the consequences of the resulting greenhouse effects are deemed inevitable. Atmospheric warming on a global scale of as much as 5°C cannot be avoided, only perhaps delayed by a few years at best (Environ. Sci. Technol, 18, 45A-46A, 1984). The cause is the burning of fossil fuels. Oil will not be too important because its supplies are predictably exhausted on the time scale of 50-100 years. Coal burning is considered as the main source of carbon dioxide. Among the more spectacular results of a global temperature rise over the next 100 years is the expected rise in sea level of a minimum of 70 cm (Oceanus, Winter, 1983/84). If the West Antarctic Ice Sheet breaks up and melts, the rise could be in the several meter range. Sea level rose only 15 cm in the past century.

  9. Sea Level Change, A Fundamental Process When Interpreting Coastal Geology and Geography.

    ERIC Educational Resources Information Center

    Zeigler, John M.

    1985-01-01

    Discusses the meaning of sea level change and identifies the major factors responsible for this occurrence. Elaborates on the theory and processes involved in indirect measurement of changes in sea volume. Also explains how crustal movement affects sea level. (ML)

  10. Benchmarking and testing the "Sea Level Equation

    NASA Astrophysics Data System (ADS)

    Spada, G.; Barletta, V. R.; Klemann, V.; van der Wal, W.; James, T. S.; Simon, K.; Riva, R. E. M.; Martinec, Z.; Gasperini, P.; Lund, B.; Wolf, D.; Vermeersen, L. L. A.; King, M. A.

    2012-04-01

    The study of the process of Glacial Isostatic Adjustment (GIA) and of the consequent sea level variations is gaining an increasingly important role within the geophysical community. Understanding the response of the Earth to the waxing and waning ice sheets is crucial in various contexts, ranging from the interpretation of modern satellite geodetic measurements to the projections of future sea level trends in response to climate change. All the processes accompanying GIA can be described solving the so-called Sea Level Equation (SLE), an integral equation that accounts for the interactions between the ice sheets, the solid Earth, and the oceans. Modern approaches to the SLE are based on various techniques that range from purely analytical formulations to fully numerical methods. Despite various teams independently investigating GIA, we do not have a suitably large set of agreed numerical results through which the methods may be validated. Following the example of the mantle convection community and our recent successful Benchmark for Post Glacial Rebound codes (Spada et al., 2011, doi: 10.1111/j.1365-246X.2011.04952.x), here we present the results of a benchmark study of independently developed codes designed to solve the SLE. This study has taken place within a collaboration facilitated through the European Cooperation in Science and Technology (COST) Action ES0701. The tests involve predictions of past and current sea level variations, and 3D deformations of the Earth surface. In spite of the signi?cant differences in the numerical methods employed, the test computations performed so far show a satisfactory agreement between the results provided by the participants. The differences found, which can be often attributed to the different numerical algorithms employed within the community, help to constrain the intrinsic errors in model predictions. These are of fundamental importance for a correct interpretation of the geodetic variations observed today, and

  11. A NOAA/NOS Sea Level Advisory

    NASA Astrophysics Data System (ADS)

    Sweet, W.

    2011-12-01

    In order for coastal communities to realize current impacts and become resilient to future changes, sea level advisories/bulletins are necessary that systematically monitor and document non-tidal anomalies (residuals) and flood-watch (elevation) conditions. The need became apparent after an exceptional sea level anomaly along the U.S. East Coast in June - July of 2009 when higher than normal sea levels coincided with a perigean-spring tide and flooded many coastal regions. The event spurred numerous public inquiries to the National Oceanic and Atmospheric Administration's (NOAA) Center for Operational Oceanographic Products and Services (CO-OPS) from coastal communities concerned because of the lack of any coastal storm signatures normally associated with such an anomaly. A subsequent NOAA report provided insight into some of the mechanisms involved in the event and methods for tracking their reoccurrences. NOAA/CO-OPS is the U.S. authority responsible for defining sea level datums and tracking their relative changes in support of marine navigation and national and state land-use boundaries. These efforts are supported by the National Water Level Observation Network (NWLON), whose long-term and widespread observations largely define a total water level measurement impacting a coastal community. NWLON time series provide estimates of local relative sea level trends, a product increasingly utilized by various stakeholders planning for the future. NWLON data also capture significant short-term changes and conveyance of high-water variations (from surge to seasonal scale) provides invaluable insight into inundation patterns ultimately needed for a more comprehensive planning guide. A NOAA/CO-OPS Sea Level Advisory Project will enhance high-water monitoring capabilities by: - Automatically detecting sea level anomalies and flood-watch occurrences - Seasonally calibrating the anomaly thresholds to a locality in terms of flood potential - Alerting for near

  12. Sea-level changes before large earthquakes

    USGS Publications Warehouse

    Wyss, M.

    1978-01-01

    Changes in sea level have long been used as a measure of local uplift and subsidence associated with large earthquakes. For instance, in 1835, the British naturalist Charles Darwin observed that sea level dropped by 2.7 meters during the large earthquake in Concepcion, CHile. From this piece of evidence and the terraces along the beach that he saw, Darwin concluded that the Andes had grown to their present height through earthquakes. Much more recently, George Plafker and James C. Savage of the U.S Geological Survey have shown, from barnacle lines, that the great 1960 Chile and the 1964 Alaska earthquakes caused several meters of vertical displacement of the shoreline. 

  13. The key role of vertical land motions in coastal sea level variations: A global synthesis of multisatellite altimetry, tide gauge data and GPS measurements

    NASA Astrophysics Data System (ADS)

    Pfeffer, Julia; Allemand, Pascal

    2016-04-01

    This study aims to quantify the vertical motions driving the decadal coastline mobility and their uncertainty at global scale. Multisatellite altimetry is combined with tide gauges and Global Positioning System (GPS) observations to evaluate the marine and crustal components of relative sea level variations. Vertical land motions and sea level variations are estimated simultaneously over the past 20 years for a network of 886 ground stations, with accuracies better than 1.7 mm/yr. The ALTIGAPS database present significant interest both by its technical characteristics (global coverage, larger number of sites, longer period of observation, improved accuracy) and by the novelty of the applications empowered. ALTIGAPS offers the opportunity to look independently into the recent dynamic processes affecting the ocean and the interior of the Earth. Here, the role of vertical land motions in relative sea level variations is explored to better understand the natural hazards associated with sea level rise in coastal areas. Global evidence for the local variability in vertical land motions is provided, which may either amplify or attenuate the apparent rise of the sea at the coast. A set of 182 potential vulnerable localities are identified by large coastal subsidence (>1.5 mm/yr) which increases by several times the effects of climate-induced sea level rise. For coastal management purposes, both marine (absolute sea level variations) and crustal (vertical land motions) components of vertical coastal motions (relative sea level variations) should therefore be accounted for.

  14. The social values at risk from sea-level rise

    SciTech Connect

    Graham, Sonia; Barnett, Jon; Fincher, Ruth; Hurlimann, Anna; Mortreux, Colette; Waters, Elissa

    2013-07-15

    Analysis of the risks of sea-level rise favours conventionally measured metrics such as the area of land that may be subsumed, the numbers of properties at risk, and the capital values of assets at risk. Despite this, it is clear that there exist many less material but no less important values at risk from sea-level rise. This paper re-theorises these multifarious social values at risk from sea-level rise, by explaining their diverse nature, and grounding them in the everyday practices of people living in coastal places. It is informed by a review and analysis of research on social values from within the fields of social impact assessment, human geography, psychology, decision analysis, and climate change adaptation. From this we propose that it is the ‘lived values’ of coastal places that are most at risk from sea-level rise. We then offer a framework that groups these lived values into five types: those that are physiological in nature, and those that relate to issues of security, belonging, esteem, and self-actualisation. This framework of lived values at risk from sea-level rise can guide empirical research investigating the social impacts of sea-level rise, as well as the impacts of actions to adapt to sea-level rise. It also offers a basis for identifying the distribution of related social outcomes across populations exposed to sea-level rise or sea-level rise policies.

  15. Causes for contemporary regional sea level changes.

    PubMed

    Stammer, Detlef; Cazenave, Anny; Ponte, Rui M; Tamisiea, Mark E

    2013-01-01

    Regional sea level changes can deviate substantially from those of the global mean, can vary on a broad range of timescales, and in some regions can even lead to a reversal of long-term global mean sea level trends. The underlying causes are associated with dynamic variations in the ocean circulation as part of climate modes of variability and with an isostatic adjustment of Earth's crust to past and ongoing changes in polar ice masses and continental water storage. Relative to the coastline, sea level is also affected by processes such as earthquakes and anthropogenically induced subsidence. Present-day regional sea level changes appear to be caused primarily by natural climate variability. However, the imprint of anthropogenic effects on regional sea level-whether due to changes in the atmospheric forcing or to mass variations in the system-will grow with time as climate change progresses, and toward the end of the twenty-first century, regional sea level patterns will be a superposition of climate variability modes and natural and anthropogenically induced static sea level patterns. Attribution and predictions of ongoing and future sea level changes require an expanded and sustained climate observing system.

  16. Wave transformation across coral reefs under changing sea levels

    NASA Astrophysics Data System (ADS)

    Harris, Daniel; Power, Hannah; Vila-Conejo, Ana; Webster, Jody

    2015-04-01

    The transformation of swell waves from deep water across reef flats is the primary process regulating energy regimes in coral reef systems. Coral reefs are effective barriers removing up to 99% of wave energy during breaking and propagation across reef flats. Consequently back-reef environments are often considered low energy with only limited sediment transport and geomorphic change during modal conditions. Coral reefs, and specifically reef flats, therefore provide important protection to tropical coastlines from coastal erosion and recession. However, changes in sea level could lead to significant changes in the dissipation of swell wave energy in coral reef systems with wave heights dependent on the depth over the reef flat. This suggests that a rise in sea level would also lead to significantly higher energy conditions exacerbating the transgressive effects of sea level rise on tropical beaches and reef islands. This study examines the potential implications of different sea level scenarios on the transformation of waves across the windward reef flats of One Tree Reef, southern Great Barrier Reef. Waves were measured on the reef flats and back-reef sand apron of One Tree Reef. A one-dimensional wave model was calibrated and used to investigate wave processes on the reef flats under different mean sea level (MSL) scenarios (present MSL, +1 m MSL, and +2 m MSL). These scenarios represent both potential future sea level states and also the paleo sea level of the late Holocene in the southern Great Barrier Reef. Wave heights were shown to increase under sea level rise, with greater wave induced orbital velocities affecting the bed under higher sea levels. In general waves were more likely to entrain and transport sediment both on the reef flat and in the back reef environment under higher sea levels which has implications for not only forecasted climate change scenarios but also for interpreting geological changes during the late Holocene when sea levels were 1

  17. Using Sea Level Change as a Climate Indicator

    NASA Astrophysics Data System (ADS)

    Masters, D. S.; Nerem, R. S.

    2014-12-01

    Sea level rise is one the more important risks due to climate change. Multiple satellite altimeters flying on the same repeating ground track have allowed estimation of global and regional sea level for the past 20 years, and the time series has yielded information about how sea level is responding to climate change. Due to the duration, consistency, and inter-calibration of the altimeter measurements, the time series is now considered a climate data record. The time series has also shown the strong dependence of sea level on interannual signals such as the ENSO and PDO. Global mean sea level change as estimated by the altimeters is arguably one of the most sensitive indicators of climate change because it varies almost entirely due to thermal expansion/contraction and the exchange of water between the land and oceans. Contributions to the latter include melting land ice and changes in the hydrologic cycle. While thermal expansion does not vary greatly on interannual time-scales, variations in the global hydrologic cycle and land ice melt can contribute to large variations in the sea level record. Isolating and understanding the causes and scales of these variations is important in interpreting the observed global and regional sea level change, especially for decision-makers assessing risk and planning for adaptation and/or mitigation. Since 1992, satellite altimeter measurements from the TOPEX/Poseidon and Jason missions, have been providing precise estimates of sea level change between ±66° latitude every 10 days. We have been using these measurements to monitor both global average and regional sea level change. The GRACE mission has provided monthly estimates of the time-varying gravity field for the last 10 years. These measurements can estimate variations in global ocean mass, mass changes in the polar ice sheets and mountain glaciers, as well as changes in the land surface water storage. These data sets can be used to inform us about the sea level change

  18. Sea level change: a philosophical approach

    NASA Astrophysics Data System (ADS)

    Leinfelder, R.; Seyfried, H.

    1993-07-01

    The present Cenozoic era is an ‘icehouse’ episode characterized by a low sea level. Since the beginning of the industrial revolution, the human race has been emitting greenhouse gases, increasing the global atmospheric temperature, and causing a rise in sea level. If emissions continue to increase at the present rate, average global temperatures may rise by 1.5°C by the year 2050, accompanied by a rise of about 30 cm in sea level. However, the prediction of future climatic conditions and sea level is hampered by the difficulty in modelling the interactions between the lithosphere, kryosphere, biosphere and atmosphere; in addition, the buffering capacity of our planet is still poorly understood. As scientists cannot offer unambiguous answers to simple questions, sorcerer's apprentices fill in the gaps, presenting plans to save planet without inconveniencing us. The geological record can help us to learn about the regulation mechanisms of our planet, many of which are connected with or expressed as sea level changes. Global changes in sea level are either tectono-eustatic or glacioeustatic. Plate tectonic processes strongly control sea levels and climate in the long term. There is a strong feed-back mechanism between sea level and climate; both can influence and determine each other. Although high sea levels are a powerful climatic buffer, falling sea levels accelerate climatic accentuation, the growth of the polar ice caps and will hence amplify the drop in sea level. Important sources of fossil greenhouse gases are botanic CO2 production, CO2 released by volcanic activity, and water vapour. The latter is particularly important when the surface area of the sea increases during a rise in sea level (‘maritime greenhouse effect’). A ‘volcanogenic greenhouse effect’ (release of volcanogenic CO2) is possibly not equally important, as intense volcanic activity may take place both during icehouse episodes as well as during greenhouse episodes. The hydrosphere

  19. Sea level oscillations over minute timescales: a global perspective

    NASA Astrophysics Data System (ADS)

    Vilibic, Ivica; Sepic, Jadranka

    2016-04-01

    Sea level oscillations occurring over minutes to a few hours are an important contributor to sea level extremes, and a knowledge on their behaviour is essential for proper quantification of coastal marine hazards. Tsunamis, meteotsunamis, infra-gravity waves and harbour oscillations may even dominate sea level extremes in certain areas and thus pose a great danger for humans and coastal infrastructure. Aside for tsunamis, which are, due to their enormous impact to the coastlines, a well-researched phenomena, the importance of other high-frequency oscillations to the sea level extremes is still underrated, as no systematic long-term measurements have been carried out at a minute timescales. Recently, Intergovernmental Oceanographic Commission (IOC) established Sea Level Monitoring Facility portal (http://www.ioc-sealevelmonitoring.org), making 1-min sea level data publicly available for several hundred tide gauge sites in the World Ocean. Thereafter, a global assessment of oscillations over tsunami timescales become possible; however, the portal contains raw sea level data only, being unchecked for spikes, shifts, drifts and other malfunctions of instruments. We present a quality assessment of these data, estimates of sea level variances and contributions of high-frequency processes to the extremes throughout the World Ocean. This is accompanied with assessment of atmospheric conditions and processes which generate intense high-frequency oscillations.

  20. A glacial isostatic adjustment model for the central and northern Laurentide Ice Sheet based on relative sea level and GPS measurements

    NASA Astrophysics Data System (ADS)

    Simon, K. M.; James, T. S.; Henton, J. A.; Dyke, A. S.

    2016-06-01

    The thickness and equivalent global sea level contribution of an improved model of the central and northern Laurentide Ice Sheet is constrained by 24 relative sea level histories and 18 present-day GPS-measured vertical land motion rates. The final model, termed Laur16, is derived from the ICE-5G model by holding the timing history constant and iteratively adjusting the thickness history, in four regions of northern Canada. In the final model, the last glacial maximum (LGM) thickness of the Laurentide Ice Sheet west of Hudson Bay was ˜3.4-3.6 km. Conversely, east of Hudson Bay, peak ice thicknesses reached ˜4 km. The ice model thicknesses inferred for these two regions represent, respectively, a ˜30 per cent decrease and an average ˜20-25 per cent increase to the load thickness relative to the ICE-5G reconstruction, which is generally consistent with other recent studies that have focussed on Laurentide Ice Sheet history. The final model also features peak ice thicknesses of 1.2-1.3 km in the Baffin Island region, a modest reduction relative to ICE-5G and unchanged thicknesses for a region in the central Canadian Arctic Archipelago west of Baffin Island. Vertical land motion predictions of the final model fit observed crustal uplift rates well, after an adjustment is made for the elastic crustal response to present-day ice mass changes of regional ice cover. The new Laur16 model provides more than a factor of two improvement of the fit to the RSL data (χ2 measure of misfit) and a factor of nine improvement to the fit of the GPS data (mean squared error measure of fit), compared to the ICE-5G starting model. Laur16 also fits the regional RSL data better by a factor of two and gives a slightly better fit to GPS uplift rates than the recent ICE-6G model. The volume history of the Laur16 reconstruction corresponds to an up to 8 m reduction in global sea level equivalent compared to ICE-5G at LGM.

  1. Acceleration of Sea Level Rise Over Malaysian Seas from Satellite Altimeter

    NASA Astrophysics Data System (ADS)

    Hamid, A. I. A.; Din, A. H. M.; Khalid, N. F.; Omar, K. M.

    2016-09-01

    Sea level rise becomes our concern nowadays as a result of variously contribution of climate change that cause by the anthropogenic effects. Global sea levels have been rising through the past century and are projected to rise at an accelerated rate throughout the 21st century. Due to this change, sea level is now constantly rising and eventually will threaten many low-lying and unprotected coastal areas in many ways. This paper is proposing a significant effort to quantify the sea level trend over Malaysian seas based on the combination of multi-mission satellite altimeters over a period of 23 years. Eight altimeter missions are used to derive the absolute sea level from Radar Altimeter Database System (RADS). Data verification is then carried out to verify the satellite derived sea level rise data with tidal data. Eight selected tide gauge stations from Peninsular Malaysia, Sabah and Sarawak are chosen for this data verification. The pattern and correlation of both measurements of sea level anomalies (SLA) are evaluated over the same period in each area in order to produce comparable results. Afterwards, the time series of the sea level trend is quantified using robust fit regression analysis. The findings clearly show that the absolute sea level trend is rising and varying over the Malaysian seas with the rate of sea level varies and gradually increase from east to west of Malaysia. Highly confident and correlation level of the 23 years measurement data with an astonishing root mean square difference permits the absolute sea level trend of the Malaysian seas has raised at the rate 3.14 ± 0.12 mm yr-1 to 4.81 ± 0.15 mm yr-1 for the chosen sub-areas, with an overall mean of 4.09 ± 0.12 mm yr-1. This study hopefully offers a beneficial sea level information to be applied in a wide range of related environmental and climatology issue such as flood and global warming.

  2. Common Era Sea-Level Change

    NASA Astrophysics Data System (ADS)

    Horton, B.; Kemp, A.; Kopp, R. E., III

    2014-12-01

    The Atlantic coast of North America provides a sedimentary record of Common Era sea levels with the resolution to identify the mechanisms that cause spatial variability in sea-level rise. This coast has a small tidal range, improving the precision of sea-level reconstructions. Coastal subsidence (from glacial isostatic adjustment, GIA) creates accommodation space that is filled by salt-marsh peat and preserves accurate and precise sea-level indicators and abundant material for radiocarbon dating. In addition, the western North Atlantic Ocean is sensitive to spatial variability in sea-level change, because of static equilibrium effects from melting of the Greenland Ice Sheet, ocean circulation and wind-driven variability in the Gulf Stream and GIA induced land-level change from ongoing collapse of Laurentide forbuldge. We reveal three distinct patters in sea-level during the Common Era along the North American Atlantic coast, likely linked to wind-driven changes in the Gulf Stream: (1) Florida, sea level is essentially flat, with the record dominated by long-term geological processes; (2) North Carolina, sea level falls to a minimum near the beginning of the second millennium, climbing to an early Little Ice Age maximum in the fifteenth century, and then declining through most of the nineteenth century; and (3) New Jersey, a sea-level maximum around 900 CE, a sea-level minimum around 1500 CE, and a long-term sea-level rise through the second half of the second millennium. We combine the salt-marsh data from North American Atlantic coast with tide-gauge records and lower resolution proxies from the northern and southern hemispheres. We apply a noisy-input Gaussian process spatio-temporal modeling framework, which identifies a long-term falling global mean sea-level (GMSL), interrupted in the middle of the 19th century by an acceleration yielding a 20th century rate of rise extremely likely (probability P = 0:95) faster than any previous century in the Common Era.

  3. Satellite Altimeter Observations of Black Sea Level Variations

    NASA Technical Reports Server (NTRS)

    Korotaev, G. K.; Saenko, O. A.; Koblinsky, C. J.

    1998-01-01

    Satellite altimeter data from TOPEX/POSEIDON and ERS-1 are used to examine seasonal and mesoscale variability of the Black Sea level. Consistent processing procedures of the altimeter measurements make it possible to determine the dynamical Black Sea level with an rms accuracy about 3 cm. It is shown that the Black Sea circulation intensifies in the winter-spring seasons and attenuates in summer-autumn. The seasonal variability of sea level is accompanied by a radiation of Rossby waves from the eastern coast of the basin. Mesoscale oscillations of the dynamical sea level are found to vary spatially and temporarily. Usually, strong eddy intensity is associated with instabilities of the Rim Current. Away from this circulation feature, in the deep basin, mesoscale variability is much smaller. Mesoscale variability has a strong seasonal signal, which is out of phase with the strength of the Rim Current.

  4. Differences between mean tide level and mean sea level

    NASA Astrophysics Data System (ADS)

    Woodworth, P. L.

    2017-01-01

    This paper discusses the differences between mean tide level (MTL) and mean sea level (MSL) as demonstrated using information from a global tide gauge data set. The roles of the two main contributors to differences between MTL and MSL (the M4 harmonic of the M2 semidiurnal tide, and the combination of the diurnal tides K1 and O1) are described, with a particular focus on the spatial scales of variation in MTL-MSL due to each contributor. Findings from the tide gauge data set are contrasted with those from a state-of-the-art global tide model. The study is of interest within tidal science, but also has practical importance regarding the type of mean level used to define land survey datums. In addition, an appreciation of MTL-MSL difference is important in the use of the historical sea level data used in climate change research, with implications for some of the data stored in international databanks. Particular studies are made of how MTL and MSL might differ through the year, and if MTL is measured in daylight hours only, as has been the practice of some national geodetic agencies on occasions in the past.

  5. Global sea level linked to global temperature

    PubMed Central

    Vermeer, Martin; Rahmstorf, Stefan

    2009-01-01

    We propose a simple relationship linking global sea-level variations on time scales of decades to centuries to global mean temperature. This relationship is tested on synthetic data from a global climate model for the past millennium and the next century. When applied to observed data of sea level and temperature for 1880–2000, and taking into account known anthropogenic hydrologic contributions to sea level, the correlation is >0.99, explaining 98% of the variance. For future global temperature scenarios of the Intergovernmental Panel on Climate Change's Fourth Assessment Report, the relationship projects a sea-level rise ranging from 75 to 190 cm for the period 1990–2100. PMID:19995972

  6. Climate Adaptation and Sea Level Rise

    EPA Pesticide Factsheets

    EPA supports the development and maintenance of water utility infrastructure across the country. Included in this effort is helping the nation’s water utilities anticipate, plan for, and adapt to risks from flooding, sea level rise, and storm surge.

  7. Impact of global seismicity on sea level change assessment

    NASA Astrophysics Data System (ADS)

    Melini, D.; Piersanti, A.

    2006-03-01

    We analyze the effect of seismic activity on sea level variations by computing the time-dependent vertical crustal movement and geoid change due to coseismic deformations and postseismic relaxation effects. Seismic activity can affect both the absolute sea level, changing the Earth's gravity field and hence the geoid height, and the relative sea level (RSL), i.e., the radial distance between seafloor and geoid level. By using comprehensive seismic catalogs we assess the net effect of seismicity on tidal relative sea level measurements as well as on the global oceanic surfaces, and we obtain an estimate of absolute sea level variations of seismic origin. We modified the approach adopted in our previous analysis, considering the issue of water volume conservation by applying the sealevel equation, and we improved our computational methods, enabling us to evaluate the effect of an extremely large number of earthquakes on large grids covering the whole oceanic surface. These new potentialities allow us to perform more detailed investigations and to discover a quantitative explanation for the overall tendency of earthquakes to produce a positive global relative sea level variation. Our results confirm the finding of a previous analysis that on a global scale most of the signal is associated with a few giant thrust events and that RSL estimates obtained using tide gauge data can be sensibly affected by the seismically driven sea level signal. The recent measures of sea level obtained by satellite altimetry show a wide regional variation of sea level trends over the oceanic surface, with the largest deviations from the mean trend occurring in tectonically active regions. While our estimates of average absolute sea level variations turn out to be orders of magnitude smaller than the satellite-measured variations, we can still argue that the mass redistribution associated with aseismic tectonic processes may contribute to the observed regional variability of sea level

  8. Global mapping of nonseismic sea level oscillations at tsunami timescales

    NASA Astrophysics Data System (ADS)

    Vilibić, Ivica; Šepić, Jadranka

    2017-01-01

    Present investigations of sea level extremes are based on hourly data measured at coastal tide gauges. The use of hourly data restricts existing global and regional analyses to periods larger than 2 h. However, a number of processes occur at minute timescales, of which the most ruinous are tsunamis. Meteotsunamis, hazardous nonseismic waves that occur at tsunami timescales over limited regions, may also locally dominate sea level extremes. Here, we show that nonseismic sea level oscillations at tsunami timescales (<2 h) may substantially contribute to global sea level extremes, up to 50% in low-tidal basins. The intensity of these oscillations is zonally correlated with mid-tropospheric winds at the 99% significance level, with the variance doubling from the tropics and subtropics to the mid-latitudes. Specific atmospheric patterns are found during strong events at selected locations in the World Ocean, indicating a globally predominant generation mechanism. Our analysis suggests that these oscillations should be considered in sea level hazard assessment studies. Establishing a strong correlation between nonseismic sea level oscillations at tsunami timescales and atmospheric synoptic patterns would allow for forecasting of nonseismic sea level oscillations for operational use, as well as hindcasting and projection of their effects under past, present and future climates.

  9. Global mapping of nonseismic sea level oscillations at tsunami timescales

    PubMed Central

    Vilibić, Ivica; Šepić, Jadranka

    2017-01-01

    Present investigations of sea level extremes are based on hourly data measured at coastal tide gauges. The use of hourly data restricts existing global and regional analyses to periods larger than 2 h. However, a number of processes occur at minute timescales, of which the most ruinous are tsunamis. Meteotsunamis, hazardous nonseismic waves that occur at tsunami timescales over limited regions, may also locally dominate sea level extremes. Here, we show that nonseismic sea level oscillations at tsunami timescales (<2 h) may substantially contribute to global sea level extremes, up to 50% in low-tidal basins. The intensity of these oscillations is zonally correlated with mid-tropospheric winds at the 99% significance level, with the variance doubling from the tropics and subtropics to the mid-latitudes. Specific atmospheric patterns are found during strong events at selected locations in the World Ocean, indicating a globally predominant generation mechanism. Our analysis suggests that these oscillations should be considered in sea level hazard assessment studies. Establishing a strong correlation between nonseismic sea level oscillations at tsunami timescales and atmospheric synoptic patterns would allow for forecasting of nonseismic sea level oscillations for operational use, as well as hindcasting and projection of their effects under past, present and future climates. PMID:28098195

  10. Global mapping of nonseismic sea level oscillations at tsunami timescales.

    PubMed

    Vilibić, Ivica; Šepić, Jadranka

    2017-01-18

    Present investigations of sea level extremes are based on hourly data measured at coastal tide gauges. The use of hourly data restricts existing global and regional analyses to periods larger than 2 h. However, a number of processes occur at minute timescales, of which the most ruinous are tsunamis. Meteotsunamis, hazardous nonseismic waves that occur at tsunami timescales over limited regions, may also locally dominate sea level extremes. Here, we show that nonseismic sea level oscillations at tsunami timescales (<2 h) may substantially contribute to global sea level extremes, up to 50% in low-tidal basins. The intensity of these oscillations is zonally correlated with mid-tropospheric winds at the 99% significance level, with the variance doubling from the tropics and subtropics to the mid-latitudes. Specific atmospheric patterns are found during strong events at selected locations in the World Ocean, indicating a globally predominant generation mechanism. Our analysis suggests that these oscillations should be considered in sea level hazard assessment studies. Establishing a strong correlation between nonseismic sea level oscillations at tsunami timescales and atmospheric synoptic patterns would allow for forecasting of nonseismic sea level oscillations for operational use, as well as hindcasting and projection of their effects under past, present and future climates.

  11. Annotated Bibliography of Relative Sea Level Change

    DTIC Science & Technology

    1991-09-01

    contribution, and--future sea-level scenarios. If an accelerated rise of sea level occurs as predicted, coastal communities will be faced with deciding the...Moreover, seismic sequence analysis in ne.. u.plo- ration areas allow for reliable predictions of geologic age ahead of drilli.g and facilitate...comparable age suggest a strong seaward tilt of the outer continental shelf. The outer -shelf over the Baltimore Canyon trough geosyncline has

  12. Obstacles to adaptation decisions in the developing world: A case study of coastal protection measures and sea-level rise in Kiribati

    NASA Astrophysics Data System (ADS)

    Donner, S. D.; Webber, S.

    2014-12-01

    International aid is increasingly focused on adaptation to climate change. At recent meetings of the parties to the United Nations Framework Convention on Climate Change, the developed world agreed to rapidly increase international assistance to help the developing world respond to the impacts of climate change. Here, we examine the decision-making challenges facing internationally supported climate change adaptation projects given the large uncertainty in future climate predictions, using the example of efforts to implement coastal protection measures (e.g. sea walls, mangrove planting) in Kiribati. The central equatorial Pacific country is home to the Kiribati Adaptation Project, the first national-level climate change adaptation project supported by the World Bank. Drawing on interview and document research conducted over an 8-year period, we trace the forces influencing decisions about coastal protection measures, starting from the variability and uncertainty in climate change projections, through the trade-offs between different measures, to the social, political, and economic context in which decisions are finally made. We then discuss how sub-optimal adaptation measures may be implemented despite years of planning, consultation, and technical studies. This qualitative analysis of the real-world process of climate change adaptation reveals that embracing a culturally appropriate and short-term (~20 years) planning horizon, while not ignoring the longer-term future, may reduce the influence of scientific uncertainty on decisions and provide opportunities to learn from mistakes, reassess the science, and adjust suboptimal investments.

  13. Glacier Contributions to Sea Level Rise

    NASA Astrophysics Data System (ADS)

    Gardner, A. S.; Cogley, J. G.; Moholdt, G.; Wouters, B.; Wiese, D. N.

    2015-12-01

    Global mean sea level is rising in response to two primary factors: warming oceans and diminishing glaciers and ice sheets. If melted completely, glaciers would raise sea levels by half a meter, much less than that the 80 meters or so that would result from total melt of the massive Greenland and Antarctic ice sheets. That is why glacier contributions to sea level rise have been less studied, allowing estimates of to vary widely. Glacier contributions to sea level change are challenging to quantify as they are broadly distributed, located in remote and poorly accessible high latitude and high altitude regions, and ground observations are sparse. Advances in satellite altimetry (ICESat) and gravimetry (GRACE) have helped, but they also have their own challenges and limitations. Here we present an updated (2003-2014) synthesis of multiple techniques adapted for varying regions to show that rates of glacier loss change little between the 2003-2009 and 2003-2014 periods, accounting for roughly one third of global mean sea level rise. Over the next century and beyond glaciers are expected to continue to contribute substantial volumes of water to the world's oceans, motivating continued study of how glaciers respond to climate change that will improve projections of future sea levels.

  14. On the relationship between sea level and Spartina alterniflora production

    USGS Publications Warehouse

    Kirwan, Matthew L.; Christian, Robert R.; Blum, Linda K.; Brinson, Mark M.

    2012-01-01

    A positive relationship between interannual sea level and plant growth is thought to stabilize many coastal landforms responding to accelerating rates of sea level rise. Numerical models of delta growth, tidal channel network evolution, and ecosystem resilience incorporate a hump-shaped relationship between inundation and plant primary production, where vegetation growth increases with sea level up to an optimum water depth or inundation frequency. In contrast, we use decade-long measurements of Spartina alterniflora biomass in seven coastal Virginia (USA) marshes to demonstrate that interannual sea level is rarely a primary determinant of vegetation growth. Although we find tepid support for a hump-shaped relationship between aboveground production and inundation when marshes of different elevation are considered, our results suggest that marshes high in the intertidal zone and low in relief are unresponsive to sea level fluctuations. We suggest existing models are unable to capture the behavior of wetlands in these portions of the landscape, and may underestimate their vulnerability to sea level rise because sea level rise will not be accompanied by enhanced plant growth and resultant sediment accumulation.

  15. Developing a Coastal Risk Indicator for Sea Level Rise

    NASA Astrophysics Data System (ADS)

    Masters, D. S.; Nerem, R.

    2012-12-01

    Coastal sea level rise is one the most important potential environmental risks. Multiple satellite altimeters flying on the same repeat orbit track have allowed estimation of global mean sea level for the past 20 years, and the time series has yielded information about the average rate of sea level increase over that time. Due to the duration, consistency, and inter-calibration of the altimeter measurements, the time series is now considered a climate record. The time series has also shown the strong dependence of sea level on interannual signals such as the ENSO and the NAO. But the most important sea level effects of climate change will be felt on the regional and local scales. At these smaller scales, local effects due to topography, tides, earth deformation (glacial isostatic adjustment (GIA), subsidence, etc.), and storm surges must also be considered when estimating the risks of sea level change to coastal communities. Recently, work has begun to understand the methods applicable to estimating the risks of expected sea level change to coastal communities (Strauss et al., 2012; Tebaldi et al., 2012). Tebaldi et al (2012) merged the expected global mean sea level increase from the semi-empirical model of Vermeer and Rahmstorf (2009) with historical local tide gauges to predict increases in storm surge risk posed by increasing sea level. In this work, we will further explore the currently available data and tools that can potentially be used to provide a sea level climate change indicator and local risk assessment along US coasts. These include global and regional sea level trends from the satellite altimetry climate record, in situ tide gauge measurements and the historical extremes at each location, local tide and storm surge models, topographic surveys of vulnerable coastlines, GIA models, and measurements of local subsidence and crustal deformation rates. We will also evaluate methods to estimate the increased risk to communities from sea level change

  16. Sea Level Rise Impacts On Infrastructure Vulnerability

    NASA Astrophysics Data System (ADS)

    Pasqualini, D.; Mccown, A. W.; Backhaus, S.; Urban, N. M.

    2015-12-01

    Increase of global sea level is one of the potential consequences of climate change and represents a threat for the U.S.A coastal regions, which are highly populated and home of critical infrastructures. The potential danger caused by sea level rise may escalate if sea level rise is coupled with an increase in frequency and intensity of storms that may strike these regions. These coupled threats present a clear risk to population and critical infrastructure and are concerns for Federal, State, and particularly local response and recovery planners. Understanding the effect of sea level rise on the risk to critical infrastructure is crucial for long planning and for mitigating potential damages. In this work we quantify how infrastructure vulnerability to a range of storms changes due to an increase of sea level. Our study focuses on the Norfolk area of the U.S.A. We assess the direct damage of drinking water and wastewater facilities and the power sector caused by a distribution of synthetic hurricanes. In addition, our analysis estimates indirect consequences of these damages on population and economic activities accounting also for interdependencies across infrastructures. While projections unanimously indicate an increase in the rate of sea level rise, the scientific community does not agree on the size of this rate. Our risk assessment accounts for this uncertainty simulating a distribution of sea level rise for a specific climate scenario. Using our impact assessment results and assuming an increase of future hurricanes frequencies and intensities, we also estimate the expected benefits for critical infrastructure.

  17. Overestimation of marsh vulnerability to sea level rise

    NASA Astrophysics Data System (ADS)

    Kirwan, Matthew L.; Temmerman, Stijn; Skeehan, Emily E.; Guntenspergen, Glenn R.; Fagherazzi, Sergio

    2016-03-01

    Coastal marshes are considered to be among the most valuable and vulnerable ecosystems on Earth, where the imminent loss of ecosystem services is a feared consequence of sea level rise. However, we show with a meta-analysis that global measurements of marsh elevation change indicate that marshes are generally building at rates similar to or exceeding historical sea level rise, and that process-based models predict survival under a wide range of future sea level scenarios. We argue that marsh vulnerability tends to be overstated because assessment methods often fail to consider biophysical feedback processes known to accelerate soil building with sea level rise, and the potential for marshes to migrate inland.

  18. Overestimation of marsh vulnerability to sea level rise

    USGS Publications Warehouse

    Kirwan, Matthew L.; Temmerman, Stijn; Skeehan, Emily E.; Guntenspergen, Glenn R.; Fagherazzi, Sergio

    2016-01-01

    Coastal marshes are considered to be among the most valuable and vulnerable ecosystems on Earth, where the imminent loss of ecosystem services is a feared consequence of sea level rise. However, we show with a meta-analysis that global measurements of marsh elevation change indicate that marshes are generally building at rates similar to or exceeding historical sea level rise, and that process-based models predict survival under a wide range of future sea level scenarios. We argue that marsh vulnerability tends to be overstated because assessment methods often fail to consider biophysical feedback processes known to accelerate soil building with sea level rise, and the potential for marshes to migrate inland.

  19. Future sea-level rise in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Galassi, Gaia; Spada, Giorgio

    2014-05-01

    Secular sea level variations in the Mediterranean Sea are the result of a number of processes characterized by distinct time scales and spatial patterns. Here we predict the future sea level variations in the Mediterranean Sea to year 2050 combining the contributions from terrestrial ice melt (TIM), glacial isostatic adjustment (GIA), and the ocean response (OR) that includes the thermal expansion and the ocean circulation contributions. The three contributions are characterized by comparable magnitudes but distinctly different sea-level fingerprints across the Mediterranean basin. The TIM component of future sea-level rise is taken from Spada et al. (2013) and it is mainly driven by the melt of small glaciers and ice caps and by the dynamic ice loss from Antarctica. The sea-level fingerprint associated with GIA is studied using two distinct models available from the literature: ICE-5G(VM2) (Peltier, 2004) and the ice model progressively developed at the Research School of Earth Sciences (RSES) of the National Australian University (KL05) (see Fleming and Lambeck, 2004 and references therein). Both the GIA and the TIM sea-level predictions have been obtained with the aid of the SELEN program (Spada and Stocchi, 2007). The spatially-averaged OR component, which includes thermosteric and halosteric sea-level variations, recently obtained using a regional coupled ocean-atmosphere model (Carillo et al., 2012), vary between 2 and 7 cm according to scenarios adopted (EA1B and EA1B2, see Meehl at al., 2007). Since the sea-level variations associated with TIM mainly result from the gravitational interactions between the cryosphere components, the oceans and the solid Earth, and long-wavelength rotational variations, they are characterized by a very smooth global pattern and by a marked zonal symmetry reflecting the dipole geometry of the ice sources. Since the Mediterranean Sea is located in the intermediate far-field of major ice sources, TIM sea-level changes have sub

  20. Sea level trend and variability around Peninsular Malaysia

    NASA Astrophysics Data System (ADS)

    Luu, Q. H.; Tkalich, P.; Tay, T. W.

    2015-08-01

    are estimated at 4.4±3.1 and 4.6±2.5 mm yr-1. The geocentric rates are about 25 % faster than those measured at tide gauges around the peninsula; however, the level of uncertainty associated with VLM data is relatively high. For the common period between 1993 and 2009, geocentric sea level rise values along the Malaysian coast are similar from tide gauge records and satellite altimetry (3.1 and 2.7 mm yr-1, respectively), and arguably correspond to the global trend.

  1. A new perspective on global mean sea level (GMSL) acceleration

    NASA Astrophysics Data System (ADS)

    Watson, Phil J.

    2016-06-01

    The vast body of contemporary climate change science is largely underpinned by the premise of a measured acceleration from anthropogenic forcings evident in key climate change proxies -- greenhouse gas emissions, temperature, and mean sea level. By virtue, over recent years, the issue of whether or not there is a measurable acceleration in global mean sea level has resulted in fierce, widespread professional, social, and political debate. Attempts to measure acceleration in global mean sea level (GMSL) have often used comparatively crude analysis techniques providing little temporal instruction on these key questions. This work proposes improved techniques to measure real-time velocity and acceleration based on five GMSL reconstructions spanning the time frame from 1807 to 2014 with substantially improved temporal resolution. While this analysis highlights key differences between the respective reconstructions, there is now more robust, convincing evidence of recent acceleration in the trend of GMSL.

  2. Upper Limit for Regional Sea Level Projections

    NASA Astrophysics Data System (ADS)

    Jevrejeva, Svetlana; Jackson, Luke; Riva, Riccardo; Grinsted, Aslak; Moore, John

    2016-04-01

    With more than 150 million people living within 1 m of high tide future sea level rise is one of the most damaging aspects of warming climate. The latest Intergovernmental Panel on Climate Change report (AR5 IPCC) noted that a 0.5 m rise in mean sea level will result in a dramatic increase the frequency of high water extremes - by an order of magnitude, or more in some regions. Thus the flood threat to the rapidly growing urban populations and associated infrastructure in coastal areas are major concerns for society. Hence, impact assessment, risk management, adaptation strategy and long-term decision making in coastal areas depend on projections of mean sea level and crucially its low probability, high impact, upper range. With probabilistic approach we produce regional sea level projections taking into account large uncertainties associated with Greenland and Antarctica ice sheets contribution. We calculate the upper limit (as 95%) for regional sea level projections by 2100 with RCP8.5 scenario, suggesting that for the most coastlines upper limit will exceed the global upper limit of 1.8 m.

  3. Extended Late Pleistocene Sea Level Record

    NASA Astrophysics Data System (ADS)

    Fairbanks, R. G.; Cao, L.; Mortlock, R. A.

    2006-12-01

    Several hundred new closed system 230Th/234U and radiocarbon dates and the addition of more cores and coral samples from the islands of Barbados, Kiritimati and Araki contribute to an enhanced sea level record for the late Pleistocene ranging from the present to 240,000 yrs BP. Application of more rigorous sample screening criteria, including redundant 231Pa/235U dates have resulted in more closed system ages and better sea level resolution. In addition, a multibeam survey has mapped an extensive glacial lowstand reef on a ridge south of Barbados that is capped by a set of pinnacle reefs that grew during the early deglaciation. Among our new observations, the more detailed Barbados sea level record now resolves a Younger Dryas still- stand and a sea level drop between 16,140 and 14,690, overlapping the timing of H1 by some age estimates. The coral ages bracketing melt water pulse 1A have been further refined to 14,082 +/- 28 yrs BP and 13,632 +/- 32 yrs BP (2-sigma). The Isotope Stage 3 interstadial ended with sea level near 87.5 meters below present at 29,500 years ago before dropping to full glacial levels. The last glacial sea level lowstand began as early as 26,000 yrs BP. Extensive dating of Marine Isotope Stage 3 interstadial reefs on the islands of Araki and Barbados have added considerable resolution to this time interval and reliably bracket lowstand intervals separating the interstadials. A new diagenesis model has improved our prospecting success for closed system ages from older reefs and added some critical dates to the sparse closed-system data set for MIS-5 and MIS-7 high stand reefs..

  4. Twentieth century sea level: An enigma

    PubMed Central

    Munk, Walter

    2002-01-01

    Changes in sea level (relative to the moving crust) are associated with changes in ocean volume (mostly thermal expansion) and in ocean mass (melting and continental storage): ζ(t) = ζsteric(t) + ζeustatic(t). Recent compilations of global ocean temperatures by Levitus and coworkers are in accord with coupled ocean/atmosphere modeling of greenhouse warming; they yield an increase in 20th century ocean heat content by 2 × 1023 J (compared to 0.1 × 1023 J of atmospheric storage), which corresponds to ζgreenhouse(2000) = 3 cm. The greenhouse-related rate is accelerating, with a present value ζ̇greenhouse(2000) ≈ 6 cm/century. Tide records going back to the 19th century show no measurable acceleration throughout the late 19th and first half of the 20th century; we take ζ̇historic = 18 cm/century. The Intergovernmental Panel on Climate Change attributes about 6 cm/century to melting and other eustatic processes, leaving a residual of 12 cm of 20th century rise to be accounted for. The Levitus compilation has virtually foreclosed the attribution of the residual rise to ocean warming (notwithstanding our ignorance of the abyssal and Southern Oceans): the historic rise started too early, has too linear a trend, and is too large. Melting of polar ice sheets at the upper limit of the Intergovernmental Panel on Climate Change estimates could close the gap, but severe limits are imposed by the observed perturbations in Earth rotation. Among possible resolutions of the enigma are: a substantial reduction from traditional estimates (including ours) of 1.5–2 mm/y global sea level rise; a substantial increase in the estimates of 20th century ocean heat storage; and a substantial change in the interpretation of the astronomic record. PMID:12011419

  5. Twentieth century sea level: an enigma.

    PubMed

    Munk, Walter

    2002-05-14

    Changes in sea level (relative to the moving crust) are associated with changes in ocean volume (mostly thermal expansion) and in ocean mass (melting and continental storage): zeta(t) = zeta(steric)(t) + zeta(eustatic)(t). Recent compilations of global ocean temperatures by Levitus and coworkers are in accord with coupled ocean/atmosphere modeling of greenhouse warming; they yield an increase in 20th century ocean heat content by 2 x 10(23) J (compared to 0.1 x 10(23) J of atmospheric storage), which corresponds to zeta(greenhouse)(2000) = 3 cm. The greenhouse-related rate is accelerating, with a present value zeta(greenhouse)(2000) approximately 6 cm/century. Tide records going back to the 19th century show no measurable acceleration throughout the late 19th and first half of the 20th century; we take zeta(historic) = 18 cm/century. The Intergovernmental Panel on Climate Change attributes about 6 cm/century to melting and other eustatic processes, leaving a residual of 12 cm of 20th century rise to be accounted for. The Levitus compilation has virtually foreclosed the attribution of the residual rise to ocean warming (notwithstanding our ignorance of the abyssal and Southern Oceans): the historic rise started too early, has too linear a trend, and is too large. Melting of polar ice sheets at the upper limit of the Intergovernmental Panel on Climate Change estimates could close the gap, but severe limits are imposed by the observed perturbations in Earth rotation. Among possible resolutions of the enigma are: a substantial reduction from traditional estimates (including ours) of 1.5-2 mm/y global sea level rise; a substantial increase in the estimates of 20th century ocean heat storage; and a substantial change in the interpretation of the astronomic record.

  6. Sea level change. Inherited landscapes and sea level change.

    PubMed

    Cloetingh, Sierd; Haq, Bilal U

    2015-01-23

    Enabled by recently gained understanding of deep-seated and surficial Earth processes, a convergence of views between geophysics and sedimentary geology has been quietly taking place over the past several decades. Surface topography resulting from lithospheric memory, retained at various temporal and spatial scales, has become the connective link between these two methodologically diverse geoscience disciplines. Ideas leading to the hypothesis of plate tectonics originated largely with an oceanic focus, where dynamic and mostly horizontal movements of the crust could be envisioned. But when these notions were applied to the landscapes of the supposedly rigid plate interiors, there was less success in explaining the observed anomalies in terrestrial topography. Solid-Earth geophysics has now reached a developmental stage where vertical movements can be measured and modeled at meaningful scales and the deep-seated structures can be imaged with increasing resolution. Concurrently, there have been advances in quantifying mechanical properties of the lithosphere (the solid outer skin of Earth, usually defined to include both the crust and the solid but elastic upper mantle above the asthenosphere). The lithosphere acts as the intermediary that transfers the effects of mantle dynamics to the surface. These developments have allowed us to better understand the previously puzzling topographic features of plate interiors and continental margins. On the sedimentary geology side, new quantitative modeling techniques and holistic approaches to integrating source-to-sink sedimentary systems have led to clearer understanding of basin evolution and sediment budgets that allow the reconstruction of missing sedimentary records and past geological landscapes.

  7. Climate And Sea Level: It's In Our Hands Now

    NASA Astrophysics Data System (ADS)

    Turrin, M.; Bell, R. E.; Ryan, W. B. F.

    2014-12-01

    Changes in sea level are measurable on both a local and a global scale providing an accessible way to connect climate to education, yet engaging teachers and students with the complex science that is behind the change in sea level can be a challenge. Deciding how much should be included and just how it should be introduced in any single classroom subject area can be an obstacle for a teacher. The Sea Level Rise Polar Explorer App developed through the PoLAR CCEP grant offers a guided tour through the many layers of science that impact sea level rise. This map-based data-rich app is framed around a series of questions that move the user through map layers with just the level of complexity they chose to explore. For a quick look teachers and students can review a 3 or 4 sentence introduction on how the given map links to sea level and then launch straight into the interactive touchable map. For a little more in depth look they can listen to (or read) a one-minute recorded background on the data displayed in the map prior to launching in. For those who want more in depth understanding they can click to a one page background piece on the topic with links to further visualizations, videos and data. Regardless of the level of complexity selected each map is composed of clickable data allowing the user to fully explore the science. The different options for diving in allow teachers to differentiate the learning for either the subject being taught or the user level of the student group. The map layers also include a range of complexities. Basic questions like "What is sea level?" talk about shorelines, past sea levels and elevations beneath the sea. Questions like "Why does sea level change?" includes slightly more complex issues like the role of ocean temperature, and how that differs from ocean heat content. And what is the role of the warming atmosphere in sea level change? Questions about "What about sea level in the past?" can bring challenges for students who have

  8. Analysis of the sea levels in Kiribati A Rising Sea of Misrepresentation Sinks Kiribati

    NASA Astrophysics Data System (ADS)

    Parker, Albert

    2016-03-01

    The sea levels of Kiribati have been stable over the last few decades, as elsewhere in the world. The Australian government funded Pacific Sea Level Monitoring (PSLM) project has adjusted sea level records to produce an unrealistic rising trend. Some information has been hidden or neglected, especially from sources of different management. The measured monthly average mean sea levels suffer from subsidence or manipulation resulting in a tilting from the about 0 (zero) mm/year of nearby tide gauges to 4 (four) mm/year over the same short time window. Real environmental problems are driven by the increasing local population leading to troubles including scarcity of water, localized sinking and localised erosion.

  9. Visualizing Sea Level Rise with Augmented Reality

    NASA Astrophysics Data System (ADS)

    Kintisch, E. S.

    2013-12-01

    Looking Glass is an application on the iPhone that visualizes in 3-D future scenarios of sea level rise, overlaid on live camera imagery in situ. Using a technology known as augmented reality, the app allows a layperson user to explore various scenarios of sea level rise using a visual interface. Then the user can see, in an immersive, dynamic way, how those scenarios would affect a real place. The first part of the experience activates users' cognitive, quantitative thinking process, teaching them how global sea level rise, tides and storm surge contribute to flooding; the second allows an emotional response to a striking visual depiction of possible future catastrophe. This project represents a partnership between a science journalist, MIT, and the Rhode Island School of Design, and the talk will touch on lessons this projects provides on structuring and executing such multidisciplinary efforts on future design projects.

  10. Sea Level Rise in Santa Clara County

    NASA Technical Reports Server (NTRS)

    Milesi, Cristina

    2005-01-01

    Presentation by Cristina Milesi, First Author, NASA Ames Research Center, Moffett Field, CA at the "Meeting the Challenge of Sea Level Rise in Santa Clara County" on June 19, 2005 Santa Clara County, bordering with the southern portion of the San Francisco Bay, is highly vulnerable to flooding and to sea level rise (SLR). In this presentation, the latest sea level rise projections for the San Francisco Bay will be discussed in the context of extreme water height frequency and extent of flooding vulnerability. I will also present preliminary estimations of levee requirements and possible mitigation through tidal restoration of existing salt ponds. The examples will draw mainly from the work done by the NASA Climate Adaptation Science Investigators at NASA Ames.

  11. The Enigma of 20th century sea level change

    NASA Astrophysics Data System (ADS)

    Cathles, Larry

    2014-05-01

    Sea level has been constant at near-present levels from ~5500 calendar years BP to the end of the Little Ice Age at ~1860 AD. Since ~1900, tide gauge measurements indicate that it has risen steadily at ~2 mm/yr by about 18 cm. The comparative stability of sealevel from 5500 cal yr BP to 1860 AD is robust, being suggested by near-shore Mediterranean archeological sites, the few sea level records that extend back to 1700 AD, and the impossibility of projecting the current sea level rise of ~2 mm/y back 5000 years (it would produce a global 10 m inundation, which is not observed) (Douglas et al., 2001, Academic Press). The post 1870 sea level rise is not due to heating of the upper ocean (Liviticus et al., 2000, Science). Munk (2002, PNAS) characterized it as an "enigma", dismissing an upper ocean steric sea level explanation as "too little" (~3 cm), "too late" (the rise started in 1860), and "too linear" (not accelerating with the accelerating CO2 increase). GRACE gravity measurements show a near zero change in ocean mass. Cazenave et al. (2009, Global and Planetary Change) indicate a slight decrease in ocean mass between 2003 and 2008. The rate of meltwater mass being added to the oceans essentially equals the GIA correction (Chambers et al., 2010, JGR). Different GIA models give ocean mass increase ranging from 0.5 to 2 mm/y of equivalent sea level rise. Our GIA model suggests no ocean mass increases (~0 mm/y of equivalent sea level rise). In this talk I show that the heating of a two layer ocean model driven by the temperature changes that have occurred over the last 1000 years since the peak of the Medieval Warm Period produces a ~2mm/yr linear sea level rise over the last 100 years with much smaller preceding sea level changes. Ocean mass could be unchanging over the last century as well as the last ~5000 years. This result is compatible with GRACE measurements and eclipse data constraints, predictions of our GIA model, and it resolves the enigma the 20th

  12. The Sea Level Fingerprints of Global Change

    NASA Astrophysics Data System (ADS)

    Mitrovica, J. X.; Hay, C.; Kopp, R. E., III; Morrow, E.

    2014-12-01

    It may be difficult to persuade those living in northern Europe that the sea level changes that their coastal communities face depends less on the total melting of polar ice sheets and glaciers than on the individual contributions to this total. In particular, melting of a specific ice sheet or mountain glacier drives deformational, gravitational and rotational perturbations to the Earth system that are manifest in a unique geometry, or fingerprint, of global sea level change. For example, melting from the Greenland Ice Sheet equivalent to 1 mm/yr of global mean sea level (GMSL) rise will lead to sea level rise of ~0 mm/yr in Dublin, ~0.2 mm/yr in Amsterdam, ~0.4 mm/yr in Boston and ~1.2 mm/yr in Cape Town. In contrast, if the same volume of ice melted from the West Antarctic Ice Sheet, all of the above sites would experience a sea level rise in the range 1.1-1.2 mm/yr. These fingerprints of modern ice melting, together with ocean thermal expansion and dynamic effects, and the ongoing signal from glacial isostatic adjustment in response to the last ice age, combine to produce a sea level field with significant geographic variability. In this talk I will highlight an analysis of global tide gauge records that takes full advantage of this variability to estimate both GMSL and the sources of meltwater over the last century, and to project GMSL to the end of the current century.

  13. Monthly variations of the Caspian sea level and solar activity.

    NASA Astrophysics Data System (ADS)

    Romanchuk, P. R.; Pasechnik, M. N.

    The connection between 11-year cycle of solar activity and the Caspian sea level is investigated. Seasonal changes of the Caspian sea level and annual variations of the sea level with variations of solar activity are studied. The results of the verifications of the sea level forecasts obtained with application of the rules discovered by the authors are given.

  14. Experiments in Reconstructing Twentieth-Century Sea Levels

    NASA Technical Reports Server (NTRS)

    Ray, Richard D.; Douglas, Bruce C.

    2011-01-01

    One approach to reconstructing historical sea level from the relatively sparse tide-gauge network is to employ Empirical Orthogonal Functions (EOFs) as interpolatory spatial basis functions. The EOFs are determined from independent global data, generally sea-surface heights from either satellite altimetry or a numerical ocean model. The problem is revisited here for sea level since 1900. A new approach to handling the tide-gauge datum problem by direct solution offers possible advantages over the method of integrating sea-level differences, with the potential of eventually adjusting datums into the global terrestrial reference frame. The resulting time series of global mean sea levels appears fairly insensitive to the adopted set of EOFs. In contrast, charts of regional sea level anomalies and trends are very sensitive to the adopted set of EOFs, especially for the sparser network of gauges in the early 20th century. The reconstructions appear especially suspect before 1950 in the tropical Pacific. While this limits some applications of the sea-level reconstructions, the sensitivity does appear adequately captured by formal uncertainties. All our solutions show regional trends over the past five decades to be fairly uniform throughout the global ocean, in contrast to trends observed over the shorter altimeter era. Consistent with several previous estimates, the global sea-level rise since 1900 is 1.70 +/- 0.26 mm/yr. The global trend since 1995 exceeds 3 mm/yr which is consistent with altimeter measurements, but this large trend was possibly also reached between 1935 and 1950.

  15. Quantitative constraints on the sea-level fall that terminated the Littorina Sea Stage, southern Scandinavia

    NASA Astrophysics Data System (ADS)

    Clemmensen, Lars B.; Murray, Andrew S.; Nielsen, Lars

    2012-04-01

    The island of Anholt in the Kattegat sea (southern Scandinavia) is made up largely of an extensive beach-ridge plain. As a result of post-glacial uplift, the earliest beach-ridge and swale deposits are now raised 8-9 m above present mean sea level. It appears that growth of the plain has been almost uninterrupted over the past 7500 years; here we constrain the evolution of this plain between 6300 and 1300 years ago using optically stimulated luminescence dates. The topography and internal architecture of the fossil shoreline deposits were measured on high-resolution maps and in ground-penetrating radar (GPR) reflection data with a vertical resolution of ˜0.25 m. Shoreline topography shows significant changes with time, and it appears that one of the most striking changes took place between 4300 and 3600 years ago; in the shoreline deposits corresponding to this time interval the surface drops by around 3.5 m suggesting a marked fall in relative sea-level. Assuming a constant uplift rate of 1.2 mm/yr, the corresponding drop in absolute sea-level is estimated to be around 2.6 m. This marked sea-level fall in 700 years took place at the transition from the Middle Holocene Thermal Maximum to the Late Holocene Thermal Decline or at the end of the Littorina Sea stage in the Baltic Sea region.

  16. Sudden change: Climate and sea level

    SciTech Connect

    Tanner, W.F.

    1995-10-01

    Dates, magnitudes and rates of Holocene sea-level changes were reviewed at the 1995 meeting of the American Association for the Advancement of Science. Richard B. Alley (Penn. State U.) described laminae in Greenland ice cores, with details at the annual level. A major event of unknown nature occurred at roughly 8,000 B.P. Gerard Bond (Lamont-Doherty Observ., N.Y.) described sediment cores from the North Atlantic, with a major event at 8,000 B.P. Published work of K.S. Petersen (Danish Geol. Survey) from a well near Vust (Denmark) was reviewed: A rapid sea level rise (25 m), then a similar drop centered at 8,000 B.P. at 8-15 cm/yr. W.F. Tanner (Florida State U.) described the beach ridge plain in northern Denmark, where a sequence of more than 270 Holocene ridges shows the date of the big Mid-Holocene sea level change couplet, 8,000 B.P., with a magnitude of {open_quotes}more than 14 m,{close_quotes} plus smaller changes. These data showed vertical magnitudes of the larger sea level events (except the Mid-Holocene catastrophe) in the range of 1-to-5 meters. W.C. Parker (Florida State) sought possible cycles in the same sequence, but they were too poorly defined for detailed forecasts. Charles R. Bentley (U. of Wisconsin) examined the possibility of an early collapse of the West Antarctic marine ice sheet, with a sea level rise of about 5 meters, but concluded that it is unlikely.

  17. Sea Grant Education at the University Level.

    ERIC Educational Resources Information Center

    Fiske, Shirley J.

    1998-01-01

    Sea Grant's investment in university-level education shows a diversity of avenues for supporting students from experience-based internships, merit scholarships, and fellowships to team-based multidisciplinary undergraduate education. Describes such programs as Undergraduate Research Opportunities in ocean engineering, graduate research…

  18. Sea Level Rise National Coastal Property Model

    EPA Science Inventory

    The impact of sea level rise on coastal properties depends critically on the human response to the threat, which in turn depends on several factors, including the immediacy of the risk, the magnitude of property value at risk, options for adapting to the threat and the cost of th...

  19. Sea-Level Changes during the Tertiary.

    ERIC Educational Resources Information Center

    Vail, Peter R.; Hardenbol, Jan

    1979-01-01

    Discussed are research procedures undertaken to determine the magnitude and timing of eustatic sea-level changes during the Tertiary Period. Data now becoming available give scientists a knowledge of conditions that may have been conducive to the formation of petroleum. (BT)

  20. Impact of Altimeter Data Processing on Sea Level Studies

    PubMed Central

    Fernandes, M. Joana; Barbosa, Susana; Lázaro, Clara

    2006-01-01

    This study addresses the impact of satellite altimetry data processing on sea level studies at regional scale, with emphasis on the influence of various geophysical corrections and satellite orbit on the structure of the derived interannual signal and sea level trend. The work focuses on the analysis of TOPEX data for a period of over twelve years, for three regions in the North Atlantic: Tropical (0°≤φ≤25°), Sub-Tropical (25°≤φ≤50°) and Sub-Arctic (50°≤φ≤65°). For this analysis corrected sea level anomalies with respect to a mean sea surface model have been derived from the GDR-Ms provided by AVISO by applying various state-of-the-art models for the geophysical corrections. Results show that sea level trend determined from TOPEX altimetry is dependent on the adopted models for the major geophysical corrections. The main effects come from the sea state bias (SSB), and from the application or not of the inverse barometer (IB) correction. After an appropriate modelling of the TOPEX A/B bias, the two analysed SSB models induce small variations in sea level trend, from 0.0 to 0.2 mm/yr, with a small latitude dependence. The difference in sea level trend determined by a non IB-corrected series and an IB-corrected one has a strong regional dependence with large differences in the shape of the interannual signals and in the derived linear trends. The use of two different drift models for the TOPEX Microwave Radiometer (TMR) has a small but non negligible effect on the North Atlantic sea level trend of about 0.1 mm/yr. The interannual signals of sea level time series derived with the NASA and the CNES orbits respectively, show a small departure in the middle of the series, which has no impact on the derived sea level trend. These results strike the need for a continuous improvement in the modelling of the various effects that influence the altimeter measurement.

  1. Simultaneous estimation of lithospheric uplift rates and absolute sea level change in southwest Scandinavia from inversion of sea level data

    NASA Astrophysics Data System (ADS)

    Nielsen, Lars; Hansen, Jens Morten; Hede, Mikkel Ulfeldt; Clemmensen, Lars B.; Pejrup, Morten; Noe-Nygaard, Nanna

    2014-11-01

    Relative sea level curves contain coupled information about absolute sea level change and vertical lithospheric movement. Such curves may be constructed based on, for example tide gauge data for the most recent times and different types of geological data for ancient times. Correct account for vertical lithospheric movement is essential for estimation of reliable values of absolute sea level change from relative sea level data and vise versa. For modern times, estimates of vertical lithospheric movement may be constrained by data (e.g. GPS-based measurements), which are independent from the relative sea level data. Similar independent data do not exist for ancient times. The purpose of this study is to test two simple inversion approaches for simultaneous estimation of lithospheric uplift rates and absolute sea level change rates for ancient times in areas where a dense coverage of relative sea level data exists and well-constrained average lithospheric movement values are known from, for example glacial isostatic adjustment (GIA) models. The inversion approaches are tested and used for simultaneous estimation of lithospheric uplift rates and absolute sea level change rates in southwest Scandinavia from modern relative sea level data series that cover the period from 1900 to 2000. In both approaches, a priori information is required to solve the inverse problem. A priori information about the average vertical lithospheric movement in the area of interest is critical for the quality of the obtained results. The two tested inversion schemes result in estimated absolute sea level rise of ˜1.2/1.3 mm yr-1 and vertical uplift rates ranging from approximately -1.4/-1.2 mm yr-1 (subsidence) to about 5.0/5.2 mm yr-1 if an a priori value of 1 mm yr-1 is used for the vertical lithospheric movement throughout the study area. In case the studied time interval is broken into two time intervals (before and after 1970), absolute sea level rise values of ˜0.8/1.2 mm yr-1 (before

  2. Sea-level and deep-sea-temperature variability over the past 5.3 million years.

    PubMed

    Rohling, E J; Foster, G L; Grant, K M; Marino, G; Roberts, A P; Tamisiea, M E; Williams, F

    2014-04-24

    Ice volume (and hence sea level) and deep-sea temperature are key measures of global climate change. Sea level has been documented using several independent methods over the past 0.5 million years (Myr). Older periods, however, lack such independent validation; all existing records are related to deep-sea oxygen isotope (δ(18)O) data that are influenced by processes unrelated to sea level. For deep-sea temperature, only one continuous high-resolution (Mg/Ca-based) record exists, with related sea-level estimates, spanning the past 1.5 Myr. Here we present a novel sea-level reconstruction, with associated estimates of deep-sea temperature, which independently validates the previous 0-1.5 Myr reconstruction and extends it back to 5.3 Myr ago. We find that deep-sea temperature and sea level generally decreased through time, but distinctly out of synchrony, which is remarkable given the importance of ice-albedo feedbacks on the radiative forcing of climate. In particular, we observe a large temporal offset during the onset of Plio-Pleistocene ice ages, between a marked cooling step at 2.73 Myr ago and the first major glaciation at 2.15 Myr ago. Last, we tentatively infer that ice sheets may have grown largest during glacials with more modest reductions in deep-sea temperature.

  3. Measuring Your Fitness Level

    MedlinePlus

    Healthy Lifestyle Fitness Ready to start a fitness program? Measure your fitness level with a few simple tests. ... 14, 2017 Original article: http://www.mayoclinic.org/healthy-lifestyle/fitness/in-depth/fitness/art-20046433 . Mayo Clinic ...

  4. Ice sheet systems and sea level change.

    NASA Astrophysics Data System (ADS)

    Rignot, E. J.

    2015-12-01

    Modern views of ice sheets provided by satellites, airborne surveys, in situ data and paleoclimate records while transformative of glaciology have not fundamentally changed concerns about ice sheet stability and collapse that emerged in the 1970's. Motivated by the desire to learn more about ice sheets using new technologies, we stumbled on an unexplored field of science and witnessed surprising changes before realizing that most were coming too fast, soon and large. Ice sheets are integrant part of the Earth system; they interact vigorously with the atmosphere and the oceans, yet most of this interaction is not part of current global climate models. Since we have never witnessed the collapse of a marine ice sheet, observations and exploration remain critical sentinels. At present, these observations suggest that Antarctica and Greenland have been launched into a path of multi-meter sea level rise caused by rapid climate warming. While the current loss of ice sheet mass to the ocean remains a trickle, every mm of sea level change will take centuries of climate reversal to get back, several major marine-terminating sectors have been pushed out of equilibrium, and ice shelves are irremediably being lost. As glaciers retreat from their salty, warm, oceanic margins, they will melt away and retreat slower, but concerns remain about sea level change from vastly marine-based sectors: 2-m sea level equivalent in Greenland and 23-m in Antarctica. Significant changes affect 2/4 marine-based sectors in Greenland - Jakobshavn Isb. and the northeast stream - with Petermann Gl. not far behind. Major changes have affected the Amundsen Sea sector of West Antarctica since the 1980s. Smaller yet significant changes affect the marine-based Wilkes Land sector of East Antarctica, a reminder that not all marine-based ice is in West Antarctica. Major advances in reducing uncertainties in sea level projections will require massive, interdisciplinary efforts that are not currently in place

  5. How Much Are Floridians Willing to Pay for Protecting Sea Turtles from Sea Level Rise?

    NASA Astrophysics Data System (ADS)

    Hamed, Ahmed; Madani, Kaveh; Von Holle, Betsy; Wright, James; Milon, J. Walter; Bossick, Matthew

    2016-01-01

    Sea level rise (SLR) is posing a great inundation risk to coastal areas. Some coastal nesting species, including sea turtle species, have experienced diminished habitat from SLR. Contingent valuation method (CVM) was used in an effort to assess the economic loss impacts of SLR on sea turtle nesting habitats for Florida coasts; and to elicit values of willingness to pay (WTP) of Central Florida residents to implement certain mitigation strategies, which would protect Florida's east coast sea turtle nesting areas. Using the open-ended and dichotomous choice CVM, we sampled residents of two Florida communities: Cocoa Beach and Oviedo. We estimated the WTP of households from these two cities to protect sea turtle habitat to be between 42 and 57 per year for 5 years. Additionally, we attempted to assess the impact of the both the respondents' demographics and their perception toward various situations on their WTP value. Findings include a negative correlation between the age of a respondent and the probability of an individual willing to pay the hypothetical WTP amount. We found that WTP of an individual was not dependent on prior knowledge of the effects of SLR on sea turtle habitat. The greatest indicators of whether or not an individual was willing to pay to protect sea turtle habitat were the respondents' perception regarding the trustworthiness and efficiency of the party which will implement the conservation measures and their confidence in the conservation methods used. Respondents who perceive sea turtles having an effect on their life were also more likely to pay.

  6. How Much Are Floridians Willing to Pay for Protecting Sea Turtles from Sea Level Rise?

    PubMed

    Hamed, Ahmed; Madani, Kaveh; Von Holle, Betsy; Wright, James; Milon, J Walter; Bossick, Matthew

    2016-01-01

    Sea level rise (SLR) is posing a great inundation risk to coastal areas. Some coastal nesting species, including sea turtle species, have experienced diminished habitat from SLR. Contingent valuation method (CVM) was used in an effort to assess the economic loss impacts of SLR on sea turtle nesting habitats for Florida coasts; and to elicit values of willingness to pay (WTP) of Central Florida residents to implement certain mitigation strategies, which would protect Florida's east coast sea turtle nesting areas. Using the open-ended and dichotomous choice CVM, we sampled residents of two Florida communities: Cocoa Beach and Oviedo. We estimated the WTP of households from these two cities to protect sea turtle habitat to be between $42 and $57 per year for 5 years. Additionally, we attempted to assess the impact of the both the respondents' demographics and their perception toward various situations on their WTP value. Findings include a negative correlation between the age of a respondent and the probability of an individual willing to pay the hypothetical WTP amount. We found that WTP of an individual was not dependent on prior knowledge of the effects of SLR on sea turtle habitat. The greatest indicators of whether or not an individual was willing to pay to protect sea turtle habitat were the respondents' perception regarding the trustworthiness and efficiency of the party which will implement the conservation measures and their confidence in the conservation methods used. Respondents who perceive sea turtles having an effect on their life were also more likely to pay.

  7. Functional Measures of Sea Turtle Hearing

    DTIC Science & Technology

    2005-09-01

    anatomy among stages and species and physiologically by brainstem evoked potential techniques. Sea turtles employed in this work were provided by NMFS...SUPPLEMENTARY NOTES 14. ABSTRACT Sea turtle hearing was investigated fmorphometrically by analyzing variations in auditory anatomy a and physiologically by...A t Project Title: Functional Measures of Sea Turtle Hearing ONR Award No: N00014-02-1-0510 Organization Award No: 13051000 Final Report Award Period

  8. Sea level changes in the Holocene

    SciTech Connect

    Tanner, W.F. )

    1993-03-01

    Beach ridge data provide much information on the history of sea level changes through all of Holocene time. Two data sets start at about 12,000 B.P., one of them essentially continuous to now with data every 40--50 yrs. Another starting at 7,600 B.P. is continuous to the present. Others span the last 3,200 years. These records agree reasonably closely, and show the Little Ice Age (since 1,200 A.D.). The sea level changes in these data include the following: (a) Early Holocene crisis, about 8,000 B.P. The Swedish (Baltic Sea) record ends about this time, the Hudson Bay record starts at roughly this time, and the Danish record has a 300--500-year gap at about this time. From the latter, it appears that sea level rose sharply, shortly before 8,000 B.P., and fell again shortly after 8,000 B.P. These were the largest changes in Holocene time. The vertical change may have been as much as 12--18 meters, and the rate of change as much as 5--8 cm/yr, perhaps the maximum possible. In stable areas, evidence for these changes are now 25--30 meters below sea level. (b) Early Holocene general rise, up to about 8,000 B.P. Evidence for this is now known only on uplifted coasts. (c) Middle Holocene high, 2 m above present MSL 7,000--5,500 B.P. (d) Middle Holocene low, 3--4 m below present MSL 5,000--3,500 B.P. (e) Several changes up to 2 meters, especially since 3,000 B.P. In general, rates of change have been close to 1 cm/yr (major exceptions noted above). The only persistent interval was that between beach ridges; each ridge and its associated swale seem to have been built by a sea-level rise-and-fall couplet, having dimensions so small (perhaps 5--30 cm) that they could be overlooked easily on tide-gauge records. The average apparent time interval was 35--50 years.

  9. A sea-level recorder for tectonic studies

    NASA Technical Reports Server (NTRS)

    Bilham, R.

    1977-01-01

    In the past tide gauges have provided valuable information concerning the vertical ground deformation associated with major earthquakes. Although tide-gauge data contains numerous sources of noise, a spacing of less than 40 km between gauges is indicated for a useful study of dilatant behavior, and a spacing of less than 80 km may be adequate for the study of crustal downwarping in island arcs. An inexpensive tide gauge which is designed to provide a continuous record of sea level with a measurement precision of 1 mm is described. Hydraulic filtering is incorporated into the instrument to attenuate daily tides relative to longer period variations of sea level. The instrument is designed to operate from flashlight batteries for a year unattended and to withstand temporary submersion as might be caused by tsunamis. Several of these sea-level recorders have been installed in seismic gaps in the Aleutians and in the Caribbean.

  10. Geoid Profiles in the Baltic Sea Determined Using GPS and Sea Level Surface

    NASA Astrophysics Data System (ADS)

    Jürgenson, Harli; Liibusk, Aive; Ellmann, Artu

    2008-12-01

    The idea was to compare the geoid of sea areas by an independent method, like GPS levelling, on the mainland. On the earth surface we can compare the gravimetric geoid with GPS levelling to get an accuracy estimation and tilt information. On the sea we can do it by the GPS methodology and eliminating the current water tilt corrections and the sea surface topography effect. A modern GPS device on board a ferry can store data every second and determine heights with an accuracy of a few centimetres (using the kinematic method with the postprocessing of data obtained from several base stations close to the ferry line). As a result, it is possible to observe the current water level's relative profile in reference to the ellipsoid. Some areas close to Estonia, such as the eastern part of the Gulf of Finland, are not completely covered by gravity measurements. The Baltic Sea has been measured using airborne gravimetry with the accuracy of about 2 mGal. Therefore, the gravimetric geoid is not fully reliable for the region either. If we take into account the tilt of the water level at the moment of measurement, we can observe the relative change of the geoid using an independent methodology, which serves as a comparison to the gravimetric geoid solution. The main problem during the measurement campaign, of course, was how to eliminate a water tilt. Water placement in relation to level surface is a very complex issue; special studies of that were conducted as well.

  11. Coastal subsidence and relative sea level rise

    USGS Publications Warehouse

    Ingebritsen, Steven E.; Galloway, Devin L.

    2014-01-01

    Subsurface fluid-pressure declines caused by pumping of groundwater or hydrocarbons can lead to aquifer-system compaction and consequent land subsidence. This subsidence can be rapid, as much as 30 cm per year in some instances, and large, totaling more than 13 m in extreme examples. Thus anthropogenic subsidence may be the dominant contributor to relative sea-level rise in coastal environments where subsurface fluids are heavily exploited. Maximum observed rates of human-induced subsidence greatly exceed the rates of natural subsidence of unconsolidated sediments (~0.1–1 cm yr−1) and the estimated rates of ongoing global sea-level rise (~0.3 cm yr−1).

  12. Hurricanes, sea level rise, and coastal change

    USGS Publications Warehouse

    Sallenger,, Asbury H.; Wang, Ping; Rosati, Julie D.; Roberts, Tiffany M.

    2011-01-01

    Sixteen hurricanes have made landfall along the U.S. east and Gulf coasts over the past decade. For most of these storms, the USGS with our partners in NASA and the U.S. Army Corps of Engineers have flown before and after lidar missions to detect changes in beaches and dunes. The most dramatic changes occurred when the coasts were completely submerged in an inundation regime. Where this occurred locally, a new breach was cut, like during Hurricane Isabel in North Carolina. Where surge inundated an entire island, the sand was stripped off leaving marshy outcrops behind, like during Hurricane Katrina in Louisiana. Sea level rise together with sand starvation and repeated hurricane impacts could increase the probabilities of inundation and degrade coasts more than sea level rise alone.

  13. Rising Sea Levels: Truth or Scare?

    ERIC Educational Resources Information Center

    Peacock, Alan

    2007-01-01

    When "ITV News" ran an item that shocked the author, about rising sea levels that will have caused the entire evacuation of the islands by the end of this year, he began to wonder whether the Pacific Ocean is really rising as fast as this. The media reporting of such things can be a double-edged sword. On the one hand, it brought to the author's…

  14. History of coral reefs and sea level

    SciTech Connect

    Fairbridge, R.W.

    1985-01-01

    Charles Darwin proposed crustal subsidence for atoll growth, on the Beagle, between England and Brazil, before even seeing a coral reef, on the basis of charts and discussions with Captain Fitzroy. Relative change of sea level due to crustal movements was then well-accepted from evidence of raised strandlines in Scandinavia and Scotland and sunken forests in England. Darwin added global change of sea level (tectonoeustasy) caused by remote tectonic activity, as explained by Robert Chambers (1848, p. 319). The glacioeustasy concept was mooted soon afterwards, though the term itself came later. When Suess in 1888 proposed eustatic change, he had in mind Archimedian displacement of water by sediment or lava accumulation on the sea floor. Integrated ideas of reef development also came in the 20th century. The powerful arguments against Darwin were led by Murray with his solution hypothesis, which can not be judged as good observation but from a narrow viewpoint. The Royal Society reef borings at Funafuti were heroic but at the same time misread. Subsequently came isotopic geochemistry, absolute dating, the Milankovitch insolation theory, and plate tectonics. And much more field work. The result is an integrated reef growth theory.

  15. Tracking multidecadal trends in sea level using coral microatolls

    NASA Astrophysics Data System (ADS)

    Majewski, Jedrzej; Pham, Dat; Meltzner, Aron; Switzer, Adam; Horton, Benjamin; Heng, Shu Yun; Warrick, David

    2015-04-01

    Tracking multidecadal trends in sea level using coral microatolls Jędrzej M. Majewski 1, Dat T. Pham1, Aron J. Meltzner 1, Adam D. Switzer 1, Benjamin P. Horton2, Shu Yun Heng1, David Warrick3, 1 Earth Observatory of Singapore, Nanyang Technological University, Singapore 2 Department of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ, USA 3 Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA Coral microatolls can be used to study relative sea-level change at multidecadal timescales associated with vertical land movements, climate induced sea-level rise and other oceanographic phenomena such as the El Niño/Southern Oscillation (ENSO) or Indian Ocean Dipole (IOD) with the assumption that the highest level of survival (HLS) of coral microatolls track sea level over the course of their lifetimes. In this study we compare microatoll records covering from as early as 1883 through 2013, from two sites in Indonesia, with long records (>20 years) from proximal tide gauges, satellite altimetry, and other sea-level reconstructions. We compared the HLS time series derived from open-ocean and moated (or ponded) microatolls on tectonically stable Belitung Island and a potentially tectonically active setting in Mapur Island, with sea-level reconstructions for 1950-2011. The sea-level reconstructions are based on ground and satellite measurements, combining a tide model with the Estimating the Circulation and Climate of the Ocean (ECCO) model. Our results confirm that open-ocean microatolls do track low water levels at multi decadal time scales and can be used as a proxy for relative sea level (RSL) over time. However, microatolls that are even partially moated are unsuitable and do not track RSL; rather, their growth patterns likely reflect changes in the elevation of the sill of the local pond, as reported by earlier authors. Our ongoing efforts will include an attempt to recognize similarities in moated

  16. Monitoring Sea Level At L'Estartit, Spain

    NASA Astrophysics Data System (ADS)

    Martinez-Benjamin, J.; Ortiz Castellon, M.; Martinez-Garcia, M.; Talaya, J.; Rodriguez Velasco, G.; Perez, B.

    2007-12-01

    Sea level is an environmental variable which is widely recognised as being important in many scientific disciplines as a control parameter for coastal dynamical processes or climate processes in the coupled atmosphere-ocean systems, as well as engineering applications. A major source of sea-level data are the national networks of coastal tide gauges, in Spain belonging to different institutions as the Instituto Geográfico Nacional (IGN), Puertos del Estado (PE), Instituto Hidrográfico de la Marina (IHM), Ports de la Generalitat, etc. Three Begur Cape experiences on radar altimeter calibration and marine geoid mapping made on 1999, 2000 and 2002 are overviewed. The marine geoid has been used to relate the coastal tide gauge data from l'Estartit harbour to off-shore altimetric data. The necessity to validate and calibrate the satellite's altimeter due to increasing needs in accuracy and long term integrity implies establishing calibration sites with enhanced ground based methods for sea level monitoring. A technical Spanish contribution to the calibration experience has been the design of GPS buoys and GPS catamaran taking in account the University of Colorado at Boulder and Senetosa/Capraia designs. Altimeter calibration is essential to obtain an absolute measure of sea level, as are knowing the instrument's drifts and bias. Specially designed tidegauges are necessary to improve the quality of altimetric data, preferably near the satellite track. Further, due to systematic differences a month instruments onboard different satellites, several in-situ calibrations are essentials to tie their systematic differences. L'Estartit tide gauge is a classical floating tide gauge set up in l'Estartit harbour (NE Spain) in 1990. It provides good quality information about the changes in the sea heights at centimetre level, that is the magnitude of the common tides in theMediterranean. In the framework of a Spanish Space Project, ref:ESP2001- 4534-PE, the instrumentation of sea

  17. Probabilistic assessment of sea level during the last interglacial stage.

    PubMed

    Kopp, Robert E; Simons, Frederik J; Mitrovica, Jerry X; Maloof, Adam C; Oppenheimer, Michael

    2009-12-17

    With polar temperatures approximately 3-5 degrees C warmer than today, the last interglacial stage (approximately 125 kyr ago) serves as a partial analogue for 1-2 degrees C global warming scenarios. Geological records from several sites indicate that local sea levels during the last interglacial were higher than today, but because local sea levels differ from global sea level, accurately reconstructing past global sea level requires an integrated analysis of globally distributed data sets. Here we present an extensive compilation of local sea level indicators and a statistical approach for estimating global sea level, local sea levels, ice sheet volumes and their associated uncertainties. We find a 95% probability that global sea level peaked at least 6.6 m higher than today during the last interglacial; it is likely (67% probability) to have exceeded 8.0 m but is unlikely (33% probability) to have exceeded 9.4 m. When global sea level was close to its current level (>or=-10 m), the millennial average rate of global sea level rise is very likely to have exceeded 5.6 m kyr(-1) but is unlikely to have exceeded 9.2 m kyr(-1). Our analysis extends previous last interglacial sea level studies by integrating literature observations within a probabilistic framework that accounts for the physics of sea level change. The results highlight the long-term vulnerability of ice sheets to even relatively low levels of sustained global warming.

  18. Attribution of Annual Maximum Sea Levels to Tropical Cyclones

    NASA Astrophysics Data System (ADS)

    Khouakhi, A.; Villarini, G.

    2015-12-01

    Tropical cyclones (TCs) can cause catastrophic storm surges with major social, economic, and ecological impacts in coastal areas. Understanding the contribution of TCs to extreme sea levels is therefore essential. In this work we examine the contribution of TCs to annual maximum sea levels at the global scale, including potential climate controls and temporal changes. Complete global coverage (1842-2014) of historical 6-hour best track TC records are obtained from the International Best Track Archive for Climate Stewardship (IBTrACS) data set. Hourly tide gauge data are obtained from the Joint Archive for Sea Level Research Quality Data Set. There are 177 tide gauge stations with at least 25 complete years of data between 1970 and 2014 (a complete year is defined as having more than 90% of all the hourly measurements in a year). We associate an annual maximum sea level at a given station with a TC if the center of circulation of the storm passed within a certain distance from the station within a given time window. Spatial and temporal sensitivity analyses are performed with varying time windows (6h, 12h) and buffer zones (200km and 500km) around the tide gauge stations. Results highlight large regional differences, with some locations experiencing almost ¾ of their annual maxima during the passage of a TC. The attribution of annual maximum sea level to TCs is particularly high along the coastal areas of the eastern United States, the Gulf of Mexico, China, Japan, Taiwan and Western Australia. Further analyses will examine the role played by El Niño - Southern Oscillation and the potential temporal changes in TC contributions to annual maximum sea levels.

  19. Uncertainty estimates of altimetric Global Mean Sea Level timeseries

    NASA Astrophysics Data System (ADS)

    Scharffenberg, Martin; Hemming, Michael; Stammer, Detlef

    2016-04-01

    An attempt is being presented concerned with providing uncertainty measures for global mean sea level time series. For this purpose sea surface height (SSH) fields, simulated by the high resolution STORM/NCEP model for the period 1993 - 2010, were subsampled along altimeter tracks and processed similar to techniques used by five working groups to estimate GMSL. Results suggest that the spatial and temporal resolution have a substantial impact on GMSL estimates. Major impacts can especially result from the interpolation technique or the treatment of SSH outliers and easily lead to artificial temporal variability in the resulting time series.

  20. Saharan dust aerosol over the central Mediterranean Sea: optical columnar measurements vs. aerosol load, chemical composition and marker solubility at ground level

    NASA Astrophysics Data System (ADS)

    Marconi, M.; Sferlazzo, D. M.; Becagli, S.; Bommarito, C.; Calzolai, G.; Chiari, M.; di Sarra, A.; Ghedini, C.; Gómez-Amo, J. L.; Lucarelli, F.; Meloni, D.; Monteleone, F.; Nava, S.; Pace, G.; Piacentino, S.; Rugi, F.; Severi, M.; Traversi, R.; Udisti, R.

    2013-08-01

    This study aims at the determination of the mineral contribution to PM10 in the central Mediterranean Sea on the basis of 7 yr of PM10 chemical composition daily measurements made on the island of Lampedusa (35.5° N, 12.6° E). Aerosol optical depth measurements are carried out in parallel while sampling with a multi-stage impactor, and observations with an optical particle counter were performed in selected periods. Based on daily samples, the total content and soluble fraction of selected metals are used to identify and characterize the dust events. The total contribution is determined by PIXE (particle-induced X-ray emission) while the composition of the soluble fraction by ICP-AES (inductively coupled plasma atomic emission spectroscopy) after extraction with HNO3 at pH 1.5. The average PM10 concentration at Lampedusa calculated over the period June 2004-December 2010 is 31.5 μg m-3, with low interannual variability. The annual means are below the EU annual standard for PM10, but 9.9% of the total number of daily data exceed the daily threshold value established by the European Commission for PM (50 μg m-3, European Community, EC/30/1999). The Saharan dust contribution to PM10 was derived by calculating the contribution of Al, Si, Fe, Ti, non-sea-salt (nss) Ca, nssNa, and nssK oxides in samples in which PIXE data were available. Cases with crustal content exceeding the 75th percentile of the crustal oxide content distribution were identified as dust events. Using this threshold we identify 175 events; 31.6% of them (55 events) present PM10 higher than 50 μg m-3, with dust contributing by 33% on average. The annual average crustal contribution to PM10 is 5.42 μg m-3, reaching a value as high as 67.9 μg m-3, 49% of PM10, during an intense Saharan dust event. The crustal aerosol amount and contribution to PM10 shows a very small seasonal dependence; conversely, the dust columnar burden displays an evident annual cycle, with a strong summer maximum (monthly

  1. Investigating the influence of sea level oscillations in the Danish Straits on the Baltic Sea dynamics

    NASA Astrophysics Data System (ADS)

    Tikhonova, Natalia; Gusev, Anatoly; Diansky, Nikolay; Zakharchuk, Evgeny

    2016-04-01

    related to the distance between the measurement point and open boundary. For example, in the Gulfs of Finland and Riga, the 36hr harmonic has an amplitude substantially higher than in the open sea, and in the Stockholm area, this harmonic is at the noise level. The 40dy and 121dy harmonics have slightly lower amplitudes than the original prescribed signal, but they are almost unchanged while propagating further into the sea, and in all the investigated locations have almost identical peaks of spectral density. The 3dy and 6dy harmonics significantly lost their amplitude in all parts of the sea, and spectral density peaks are at the noise level. The simulation results showed us that the Danish straits do not filter 121dy and 40dy oscillations, and their amplitude does not decrease much. The 13dy, 6dy and 3dy oscillations significantly lose in amplitude and have no significant peaks of the spectral density. The 1.5dy harmonic propagates to the Gulfs of Finland and Riga, and increases in amplitude due to resonance at the natural frequency of the basin. It is suggested that, while Danish straits do not filter or transform frequency characteristics of oscillations propagated from the North Sea, but the Baltic Sea configuration may affect the magnitude and propagation extent of these oscillations. Thus, the fluctuations in the North Sea and the Danish Straits can significantly contribute to the Baltic Sea dynamics in the low-frequency range of the spectrum, and the periods of natural oscillations of the basin. The research was supported by the Russian Foundation for Basic Research (grant № 16-05-00534) and Saint-Petersburg State University (grant №18.37.140.2014)

  2. Steric sea level change in the Bay of Bengal: investigating the most variable component of sea level change

    NASA Astrophysics Data System (ADS)

    Uebbing, Bernd; Kusche, Jürgen; Rietbroek, Roelof; Shum, Ck

    2015-04-01

    salinity products from different ARGO processing facilities. We also compare to the classical approach of subtracting the mass component, estimated by GRACE, from the total sea level change, measured by altimetry. Furthermore, we assess the sensitivity of our inversion to the normalized steric fingerprints, which are either based on ARGO fields or derived from ocean modeling. While most steric changes are taking place in the upper 700 m of the ocean, our inversion also allows us to (indirectly) assess the influence from the deep ocean, which is not negligible for the total steric trend.

  3. Measurement of light scattering in deep sea

    NASA Astrophysics Data System (ADS)

    Maragos, N.; Balasi, K.; Domvoglou, T.; Kiskiras, I.; Lenis, D.; Maniatis, M.; Stavropoulos, G.

    2016-04-01

    The deep-sea neutrino telescope in the Mediterranean Sea, being prepared by the KM3NET collaboration, will contain thousands of optical sensors to readout. The accurate knowledge of the optical properties of deep-sea water is of great importance for the neutrino event reconstruction process. In this study we describe our progress in designing an experimental setup and studying a method to measure the parameters describing the absorption and scattering characteristics of deep-sea water. Three PMTs will be used to measure in situ the scattered light emitted from six laser diodes in three different wavelengths covering the Cherenkov radiation spectrum. The technique for the evaluation of the parameters is based on Monte Carlo simulations and our results show that we are able to determine these parameters with satisfying precision.

  4. Microwave Radiometric Measurement of Sea Surface Salinity.

    DTIC Science & Technology

    1984-04-01

    potential problems of polution and urban water sup- plies. Although salinity can be measured from a surface vessel, economic consider- ations advocate...Washington, DC 20350 Commander Naval Sea System Commandaa ComAinder ATTN: Mr. C. Smith, NAVSEA 63R* Nval Air Development Center "’-’. "Washington, DC...20362 ATTN: Mr. R. Bollard, Code 2062% .’* Warminster, PA 18974 • .’.Commander CNaval Sea System CommandCoimCander Headquarters Naval Air Systems

  5. Updating Maryland's sea-level rise projections

    USGS Publications Warehouse

    Boesch, Donald F.; Atkinson, Larry P.; Boicourt, William C.; Boon, John D.; Cahoon, Donald R.; Dalrymple, Robert A.; Ezer, Tal; Horton, Benjamin P.; Johnson, Zoe P.; Kopp, Robert E.; Li, Ming; Moss, Richard H.; Parris, Adam; Sommerfield, Christopher K.

    2013-01-01

    With its 3,100 miles of tidal shoreline and low-lying rural and urban lands, “The Free State” is one of the most vulnerable to sea-level rise. Historically, Marylanders have long had to contend with rising water levels along its Chesapeake Bay and Atlantic Ocean and coastal bay shores. Shorelines eroded and low-relief lands and islands, some previously inhabited, were inundated. Prior to the 20th century, this was largely due to the slow sinking of the land since Earth’s crust is still adjusting to the melting of large masses of ice following the last glacial period. Over the 20th century, however, the rate of rise of the average level of tidal waters with respect to land, or relative sea-level rise, has increased, at least partially as a result of global warming. Moreover, the scientific evidence is compelling that Earth’s climate will continue to warm and its oceans will rise even more rapidly. Recognizing the scientific consensus around global climate change, the contribution of human activities to it, and the vulnerability of Maryland’s people, property, public investments, and natural resources, Governor Martin O’Malley established the Maryland Commission on Climate Change on April 20, 2007. The Commission produced a Plan of Action that included a comprehensive climate change impact assessment, a greenhouse gas reduction strategy, and strategies for reducing Maryland’s vulnerability to climate change. The Plan has led to landmark legislation to reduce the state’s greenhouse gas emissions and a variety of state policies designed to reduce energy consumption and promote adaptation to climate change.

  6. Geodetic infrastructure at the Barcelona harbour for sea level monitoring

    NASA Astrophysics Data System (ADS)

    Martinez-Benjamin, Juan Jose; Gili, Josep; Lopez, Rogelio; Tapia, Ana; Pros, Francesc; Palau, Vicenc; Perez, Begona

    2015-04-01

    The presentation is directed to the description of the actual geodetic infrastructure of Barcelona harbour with three tide gauges of different technologies for sea level determination and contribution to regional sea level rise and understanding past and present sea level rise in the Barcelona harbour. It is intended that the overall system will constitute a CGPS Station of the ESEAS (European Sea Level) and TIGA (GPS Tide Gauge Benchmark Monitoring) networks. At Barcelona harbour there is a MIROS radar tide gauge belonging to Puertos del Estado (Spanish Harbours).The radar sensor is over the water surface, on a L-shaped structure which elevates it a few meters above the quay shelf. 1-min data are transmitted to the ENAGAS Control Center by cable and then sent each 1 min to Puertos del Estado by e-mail. The information includes wave forescast (mean period, significant wave height, sea level, etc.This sensor also measures agitation and sends wave parameters each 20 min. There is a GPS station Leica Geosystems GRX1200 GG Pro and antenna AX 1202 GG. The Control Tower of the Port of Barcelona is situated in the North dike of the so-called Energy Pier in the Barcelona harbor (Spain). This tower has different kind of antennas for navigation monitoring and a GNSS permanent station. As the tower is founded in reclaimed land, and because its metallic structure, the 50 m building is subjected to diverse movements, including periodic fluctuations due to temperature changes. In this contribution the 2009, 2011, 2012, 2013 and 2014 the necessary monitoring campaigns are described. In the framework of a Spanish Space Project, the instrumentation of sea level measurements has been improved by providing the Barcelona site with a radar tide gauge Datamar 2000C from Geonica S.L. in June 2014 near an acoustic tide gauge from the Barcelona Harbour installed in 2013. Precision levelling has been made several times in the last two years because the tower is founded in reclaimed land and

  7. Mean Tide Level Data in the PSMSL Mean Sea Level Dataset

    NASA Astrophysics Data System (ADS)

    Matthews, Andrew; Bradshaw, Elizabeth; Gordon, Kathy; Jevrejeva, Svetlana; Rickards, Lesley; Tamisiea, Mark; Williams, Simon; Woodworth, Philip

    2016-04-01

    The Permanent Service for Mean Sea Level (PSMSL) is the internationally recognised global sea level data bank for long term sea level change information from tide gauges. Established in 1933, the PSMSL continues to be responsible for the collection, publication, analysis and interpretation of sea level data. The PSMSL operates under the auspices of the International Council for Science (ICSU), is a regular member of the ICSU World Data System and is associated with the International Association for the Physical Sciences of the Oceans (IAPSO) and the International Association of Geodesy (IAG). The PSMSL continues to work closely with other members of the sea level community through the Intergovernmental Oceanographic Commission's Global Sea Level Observing System (GLOSS). Currently, the PSMSL data bank holds over 67,000 station-years of monthly and annual mean sea level data from over 2250 tide gauge stations. Data from each site are quality controlled and, wherever possible, reduced to a common datum, whose stability is monitored through a network of geodetic benchmarks. PSMSL also distributes a data bank of measurements taken from in-situ ocean bottom pressure recorders. Most of the records in the main PSMSL dataset indicate mean sea level (MSL), derived from high-frequency tide gauge data, with sampling typically once per hour or higher. However, some of the older data is based on mean tide level (MTL), which is obtained from measurements taken at high and low tide only. While usually very close, MSL and MTL can occasionally differ by many centimetres, particularly in shallow water locations. As a result, care must be taken when using long sea level records that contain periods of MTL data. Previously, periods during which the values indicated MTL rather than MSL were noted in the documentation, and sometimes suggested corrections were supplied. However, these comments were easy to miss, particularly in large scale studies that used multiple stations from across

  8. On how climate variability influences regional sea level change

    NASA Astrophysics Data System (ADS)

    Brunnabend, Sandra-Esther; Kusche, Jürgen; Rietbroek, Roelof; Forootan, Ehsan

    2016-04-01

    Regional trends in sea level change are strongly influenced by climate variations, such as ENSO (El-Nino Southern Oscillation), the IOD (Indian Ocean Dipole), or the PDO (Pacific Decadal Oscillation). Hence, before computing long term regional sea level change, these sea level variations need to be taken into account as they lead to strong dependencies of computed regional sea level trends on the time period of the investigation. In this study, sea level change during the years 1993 to 2013 is analysed to identify the dominant modes of sea level change caused by climate variations. Here, two different gridded altimetry products are analysed, namely ESA's combined CCI SeaLevel v1.1 ECV product (doi: 10.5270/esa-sea_level_cci-1993_2013-v_1.1-201412), and absolute dynamic topography produced by Ssalto/Duacs and distributed by Aviso, with support from Cnes (http://www.aviso.altimetry.fr/duacs/). Reconstructions using the different decomposition techniques including the standard principle component analysis (PCA), rotated empirical orthogonal functions (REOF) and independent component analysis (ICA) method are analysed. They are compared with sea level change modelled with the global finite-element sea-ice ocean model (FESOM). The results indicate that from the applied methods, ICA is most suitable to separate the individual climate variability signals in independent modes of sea level change. This especially holds for extracting the ENSO contribution in sea level changes, which was better separated by applying ICA, from both altimetry and modelled sea level products. In addition, it is presented how modelled sea level change reflects climate variations compared to that identified in the altimetry products.

  9. Annual sea level amphidromes in the South China Sea revealed by merged altimeter data

    NASA Astrophysics Data System (ADS)

    Zhang, Caiyun; Wang, Bin; Chen, Ge

    2006-07-01

    Annual phase-amplitude characteristics of sea level anomaly (SLA) in the South China Sea (SCS) are investigated by a merged SLA data set derived from simultaneous measurements of Envisat, Geosat-Follow-on (GFO), Jason-1, and TOPEX/Poseidon (T/P) from January 2004 to December 2005. Four annual amphidromes instead of two are revealed and their locations, surrounding the Vietnam eddy, distinguish two distinctive regimes of annual variations in the SCS, a basin scale monsoon regime and a local Vietnam eddy regime. Their existence suggests that the annual amphidrome is not only a common feature on global scale, but also a phenomenon in regional seas. However, the locations of these amphidromes in the SCS vary considerably from year to year, in contrast to the annual amphidomes found in the tropical ocean basins, which are much more stable.

  10. Grain-size based sea-level reconstruction in the south Bohai Sea during the past 135 kyr

    NASA Astrophysics Data System (ADS)

    Yi, Liang; Chen, Yanping

    2013-04-01

    Future anthropogenic sea-level rise and its impact on coastal regions is an important issue facing human civilizations. Due to the short nature of the instrumental record of sea-level change, development of proxies for sea-level change prior to the advent of instrumental records is essential to reconstruct long-term background sea-level changes on local, regional and global scales. Two of the most widely used approaches for past sea-level changes are: (1) exploitation of dated geomorphologic features such as coastal sands (e.g. Mauz and Hassler, 2000), salt marsh (e.g. Madsen et al., 2007), terraces (e.g. Chappell et al., 1996), and other coastal sediments (e.g. Zong et al., 2003); and (2) sea-level transfer functions based on faunal assemblages such as testate amoebae (e.g. Charman et al., 2002), foraminifera (e.g. Chappell and Shackleton, 1986; Horton, 1997), and diatoms (e.g. Horton et al., 2006). While a variety of methods has been developed to reconstruct palaeo-changes in sea level, many regions, including the Bohai Sea, China, still lack detailed relative sea-level curves extending back to the Pleistocene (Yi et al., 2012). For example, coral terraces are absent in the Bohai Sea, and the poor preservation of faunal assemblages makes development of a transfer function for a relative sea-level reconstruction unfeasible. In contrast, frequent alternations between transgression and regression has presumably imprinted sea-level change on the grain size distribution of Bohai Sea sediments, which varies from medium silt to coarse sand during the late Quaternary (IOCAS, 1985). Advantages of grainsize-based relative sea-level transfer function approaches are that they require smaller sample sizes, allowing for replication, faster measurement and higher spatial or temporal resolution at a fraction of the cost of detail micro-palaeontological analysis (Yi et al., 2012). Here, we employ numerical methods to partition sediment grain size using a combined database of

  11. Distinguishing Between Natural and Anthropogenic Part of Sea Level Trends

    NASA Astrophysics Data System (ADS)

    Becker, M.; Karpytchev, M.; Lennartz-Sassinek, S.

    2014-12-01

    Detection and attribution of human influence on sea level rise are important topics that have not yet been explored in depth. From the perspective of assessing the contribution of human activities to climate changes, the sea level drivers can be partitioned in anthropogenic and natural forcing. In this study we try to answer the following two questions: (1) How large a sea level trend could be expected as result of natural internal variability? (2) Whether the sea level changes observed over the past century were natural in origin. We suppose that natural behavior of sea level consists of increases and decreases occurring with frequencies following a power law distribution and the monthly sea level records are power law long-term correlated time series. Then we search for the presence of unnatural external sea level trend by applying statistics of Lennartz and Bunde [2009]. We estimate the minimum anthropogenic sea level trend as a lower bound of statistically significant external sea level trend in the longest tide-gauge records worldwide. We apply this new method to distinguish between the trend-like natural oscillations and the external trends in the longest available sea level records and in global mean sea level reconstructions. The results show that the long-term persistence impacts strongly on sea level rise estimation. We provide statistical evidences that the observed sea level changes, at global and regional scales, are beyond its natural internal variability and cannot be explained without human influence. We found that sea level change during the past century contains an external component at 99% significance level in two thirds of the available longest tidal records worldwide. The anthropogenic sea level trend is about 1 mm/yr in global sea level reconstructions that is more than half of the total observed sea level trend during the XXth century, which is about 1.7 mm/yr. This work provides the first estimate of the minimal anthropogenic contribution

  12. Sea level trends for all sections of the Baltic Sea coastline

    NASA Astrophysics Data System (ADS)

    Madsen, Kristine S.; Høyer, Jacob L.; Suursaar, Ülo; Knudsen, Per; She, Jun

    2016-04-01

    To better understand influence of sea level rise on societal vulnerability and coastal erosion processes, it is important to know the sea level trend. The coastline of the Baltic Sea is not uniformly exposed, and therefore we will determine the sea level trend of the last 10, 50 and 100 years for all sections of the coastline. The observational record of sea level in the Baltic Sea is quite unique with several records of more than 100 years of data. However, the information is confined to the tide gauge locations. Here, we utilize a statistical method based on least squares regression and originally developed for short term sea level variability (Madsen et al. 2015, JGR, doi:10.1002/2015JC011070) to spread out the sea level information from selected tide gauges to all sections of the Baltic Sea coast. Monthly mean tide gauge observations are retrieved from PSMSL and supplemented with Estonian observations. The spatial distribution of the sea level is obtained from model reanalysis from the Copernicus Marine Service and satellite altimetry observations and land rise information is taken into account. Results are validated against independent tide gauges, providing a consistent record of 20th century sea level trends and variability, including uncertainties, for the entire Baltic Sea coastline. This work is sponsored by the EMODnet project Baltic Checkpoint.

  13. Ongoing glacial isostatic contributions to observations of sea level change

    NASA Astrophysics Data System (ADS)

    Tamisiea, Mark E.

    2011-09-01

    Studies determining the contribution of water fluxes to sea level rise typically remove the ongoing effects of glacial isostatic adjustment (GIA). Unfortunately, use of inconsistent terminology between various disciplines has caused confusion as to how contributions from GIA should be removed from altimetry and GRACE measurements. In this paper, we review the physics of the GIA corrections applicable to these measurements and discuss the differing nomenclature between the GIA literature and other studies of sea level change. We then examine a range of estimates for the GIA contribution derived by varying the Earth and ice models employed in the prediction. We find, similar to early studies, that GIA produces a small (compared to the observed value) but systematic contribution to the altimetry estimates, with a maximum range of -0.15 to -0.5 mm yr-1. Moreover, we also find that the GIA contribution to the mass change measured by GRACE over the ocean is significant. In this regard, we demonstrate that confusion in nomenclature between the terms 'absolute sea level' and 'geoid' has led to an overestimation of this contribution in some previous studies. A component of this overestimation is the incorrect inclusion of the direct effect of the contemporaneous perturbations of the rotation vector, which leads to a factor of ˜two larger value of the degree two, order one spherical harmonic component of the model results. Aside from this confusion, uncertainties in Earth model structure and ice sheet history yield a spread of up to 1.4 mm yr-1 in the estimates of this contribution. However, even if the ice and Earth models were perfectly known, the processing techniques used in GRACE data analysis can introduce variations of up to 0.4 mm yr-1. Thus, we conclude that a single-valued 'GIA correction' is not appropriate for sea level studies based on gravity data; each study must estimate a bound on the GIA correction consistent with the adopted data-analysis scheme.

  14. Sea-level rise and coastal wetlands.

    PubMed

    Blankespoor, Brian; Dasgupta, Susmita; Laplante, Benoit

    2014-12-01

    This paper seeks to quantify the impact of a1-m sea-level rise on coastal wetlands in 86 developing countries and territories. It is found that approximately 68 % of coastal wetlands in these countries are at risk. A large percentage of this estimated loss is found in Europe and Central Asia, East Asia, and the Pacific, as well as in the Middle East and North Africa. A small number of countries will be severely affected. China and Vietnam(in East Asia and the Pacific), Libya and Egypt (in the Middle East and North Africa), and Romania and Ukraine (in Europe and Central Asia) will bear most losses. In economic terms, the loss of coastal wetlands is likely to exceed $703 million per year in 2000 US dollars.

  15. NASA Now: Climate Change: Sea Level Rise

    NASA Video Gallery

    Dr. Josh Willis discusses the connection between oceans and global climate change. Learn why NASA measures greenhouse gases and how we detect ocean levels from space. These are crucial vital signs ...

  16. The impact of groundwater depletion on spatial variations in sea level change during the past century

    NASA Astrophysics Data System (ADS)

    Veit, Emeline; Conrad, Clinton P.

    2016-04-01

    Continental groundwater loss during the past century has elevated sea level by up to ~25 mm. The mass unloading associated with this depletion locally uplifts Earth's solid surface and depresses the geoid, leading to slower relative sea level rise near areas of significant groundwater loss. We computed spatial variations in sea level using a model of the solid Earth's response to estimates of groundwater depletion during the past century and find large negative deviations of ~0.4 mm/yr along the coastlines of western North America and southern Asia. This approximately corresponds to the difference between rates of sea level rise measured by tide gauges in these regions since 1930 and average rates inferred from global reconstructions. Groundwater-induced regional variations in sea level can be larger than those due to postglacial rebound and interseismic deformation and should become increasingly important in the future as both groundwater depletion and sea level rise accelerate.

  17. Groundwater depletion's contribution to sea level rise increasing

    NASA Astrophysics Data System (ADS)

    Schultz, Colin

    2011-11-01

    Since the turn of the twentieth century, industrial-scale redistribution of water from landlocked aquifers to the ocean has driven up the global average sea level by more than 12 centimeters. Between 1900 and 2008, roughly 4500 cubic kilometers of water was drawn from the ground, largely to feed an agricultural system increasingly reliant on irrigation. Of that 4500-cubic-kilometer total (nearly the volume of Lake Michigan), 1100 cubic kilometers were pumped out between 2000 and 2008 alone. This early-21st-century groundwater depletion was responsible for raising global sea level at a rate of 0.4 millimeter per year, an eighth of the observed total. These updated values, falling near the middle of the range of previous estimates, are the product of an investigation by Konikow that drew together a variety of volumetric measurements of groundwater storage.

  18. The Future of GLOSS Sea Level Data Archaeology

    NASA Astrophysics Data System (ADS)

    Jevrejeva, S.; Bradshaw, E.; Tamisiea, M. E.; Aarup, T.

    2014-12-01

    Long term climate records are rare, consisting of unique and unrepeatable measurements. However, data do exist in analogue form in archives, libraries and other repositories around the world. The Global Sea Level Observing System (GLOSS) Group of Experts aims to provide advice on locating hidden tide gauge data, scanning and digitising records and quality controlling the resulting data. Long sea level data time series are used in Intergovernmental Panel on Climate Change (IPCC) assessment reports and climate studies, in oceanography to study changes in ocean currents, tides and storm surges, in geodesy to establish national datum and in geography and geology to monitor coastal land movement. GLOSS has carried out a number of data archaeology activities over the past decade, which have mainly involved sending member organisations questionnaires on their repositories. The Group of Experts is now looking at future developments in sea level data archaeology and how new technologies coming on line could be used by member organisations to make data digitisation and transcription more efficient. Analogue tide data comes in two forms charts, which record the continuous measurements made by an instrument, usually via a pen trace on paper ledgers containing written values of observations The GLOSS data archaeology web pages will provide a list of software that member organisations have reported to be suitable for the automatic digitisation of tide gauge charts. Transcribing of ledgers has so far proved more labour intensive and is usually conducted by people entering numbers by hand. GLOSS is exploring using Citizen Science techniques, such as those employed by the Old Weather project, to improve the efficiency of transcribing ledgers. The Group of Experts is also looking at recent advances in Handwritten Text Recognition (HTR) technology, which mainly relies on patterns in the written word, but could be adapted to work with the patterns inherent in sea level data.

  19. Timescales for detecting a significant acceleration in sea level rise

    PubMed Central

    Haigh, Ivan D.; Wahl, Thomas; Rohling, Eelco J.; Price, René M.; Pattiaratchi, Charitha B.; Calafat, Francisco M.; Dangendorf, Sönke

    2014-01-01

    There is observational evidence that global sea level is rising and there is concern that the rate of rise will increase, significantly threatening coastal communities. However, considerable debate remains as to whether the rate of sea level rise is currently increasing and, if so, by how much. Here we provide new insights into sea level accelerations by applying the main methods that have been used previously to search for accelerations in historical data, to identify the timings (with uncertainties) at which accelerations might first be recognized in a statistically significant manner (if not apparent already) in sea level records that we have artificially extended to 2100. We find that the most important approach to earliest possible detection of a significant sea level acceleration lies in improved understanding (and subsequent removal) of interannual to multidecadal variability in sea level records. PMID:24728012

  20. Global sea-level changes during the past century

    NASA Technical Reports Server (NTRS)

    Gornitz, Vivien; Lebedeff, Sergej

    1987-01-01

    A novel technique, initially developed for climate studies, is used to reevaluate the estimate of relative sea-level change over the past century. The technique produces a composite regional average sea-level curve from the tide-gage data of individual stations. The effects of glacioisostasy and long-term tectonism are accounted for using late Holocene sea-level indicators. Along the east coast of North America, an apparent maximum sea-level rise is detected in both tide-gage and late Holocene sea-level indicators between Chesapeake Bay and New Jersey. Sea-level changes in western North America reveal greater spatial variations than for the east coast, which can be related to more active tectonism in California and British Columbia and to strong localized isostatic rebound in Alaska.

  1. Timescales for detecting a significant acceleration in sea level rise.

    PubMed

    Haigh, Ivan D; Wahl, Thomas; Rohling, Eelco J; Price, René M; Pattiaratchi, Charitha B; Calafat, Francisco M; Dangendorf, Sönke

    2014-04-14

    There is observational evidence that global sea level is rising and there is concern that the rate of rise will increase, significantly threatening coastal communities. However, considerable debate remains as to whether the rate of sea level rise is currently increasing and, if so, by how much. Here we provide new insights into sea level accelerations by applying the main methods that have been used previously to search for accelerations in historical data, to identify the timings (with uncertainties) at which accelerations might first be recognized in a statistically significant manner (if not apparent already) in sea level records that we have artificially extended to 2100. We find that the most important approach to earliest possible detection of a significant sea level acceleration lies in improved understanding (and subsequent removal) of interannual to multidecadal variability in sea level records.

  2. Ice volume and sea level during the last interglacial.

    PubMed

    Dutton, A; Lambeck, K

    2012-07-13

    During the last interglacial period, ~125,000 years ago, sea level was at least several meters higher than at present, with substantial variability observed for peak sea level at geographically diverse sites. Speculation that the West Antarctic ice sheet collapsed during the last interglacial period has drawn particular interest to understanding climate and ice-sheet dynamics during this time interval. We provide an internally consistent database of coral U-Th ages to assess last interglacial sea-level observations in the context of isostatic modeling and stratigraphic evidence. These data indicate that global (eustatic) sea level peaked 5.5 to 9 meters above present sea level, requiring smaller ice sheets in both Greenland and Antarctica relative to today and indicating strong sea-level sensitivity to small changes in radiative forcing.

  3. Global sea level trend in the past century

    NASA Technical Reports Server (NTRS)

    Gornitz, V.; Lebedeff, S.; Hansen, J.

    1982-01-01

    Data derived from tide-gauge stations throughout the world indicate that the mean sea level rose by about 12 centimeters in the past century. The sea level change has a high correlation with the trend of global surface air temperature. A large part of the sea level rise can be accounted for in terms of the thermal expansion of the upper layers of the ocean. The results also represent weak indirect evidence for a net melting of the continental ice sheets.

  4. The Sea Level Conundrum: Insights From Paleo Studies

    NASA Astrophysics Data System (ADS)

    Siddall, Mark; Clark, Peter; Thompson, Bill; Waelbroeck, Claire; Gregory, Jonathan; Stocker, Thomas

    2009-03-01

    Empirical Constraints on Future Sea Level Rise; Bern, Switzerland, 25-29 August 2008; Eustatic sea level (ESL) rise during the 21st century is perhaps the greatest threat from climate change, but its magnitude is contested. Geological records identify examples of nonlinear ice sheet response to climate forcing, suggesting a strategy for refining estimates of 21st-century sea level change. In August 2008, Past Global Changes (PAGES), International Marine Past Global Change Study (IMAGES), and the University of Bern cosponsored a workshop to address this possibility. The workshop highlighted several ways that paleoceanography studies can place limits on future sea level rise, and these are enlarged upon here.

  5. Demographic responses to sea level rise in California

    SciTech Connect

    Constable, A. |; Van Arsdol, M.D. Jr.; Sherman, D.J.; Wang, J.; McMullin-Messier, P.A.; Rollin, L.

    1996-12-31

    Human consequences of sea level rise in California coastal counties reflect increasing population densities. Populations of coastal counties potentially affected by sea level rise are projected to increase from 26.2 million persons in 1990 to 63.3 million persons in 2040. Urbanization dominates Los Angeles and the South Coast and San Francisco Bay and Delta regions. California shoreline populations subject to potential disruption impacts of sea level rise are increasing rapidly. Enhanced risk zones for sea level rise are specified for the Oxnard Plain of Ventura County on the south coast of California. Four separate sea level rise scenarios are considered: (1) low (sea level rise only); (2) moderate (adding erosion); (3) high (adding erosion and storm surges); and (4) a maximum case, a 3 m enhanced risk zone. Population impacts are outlined for the 3 m zone. More serious impacts from storm surges are expected than from sea level rise and erosion. Stakeholders who support or oppose policies which may expose populations to sea level rise include energy, commercial, financial, industrial, public agency, private interest and governmental organizations. These organizations respond to extreme events from differing positions. Vested interests determine the degree of mitigation employed by stakeholders to defer impacts of sea level rise.

  6. Estimation of Holocene Land Movement and Sea Level Changes in Southwest Scandinavia - Results From Interpretation of Relative Sea Level Curves

    NASA Astrophysics Data System (ADS)

    Nielsen, L.; Hede, M.; Clemmensen, L. B.; Morten Hansen, J.; Noe-Nygaard, N.; Sander, L.; Bendixen, M.; Kroon, A.; Murray, A. S.; Pejrup, M.

    2013-12-01

    Relative sea level curves from different localities in Denmark, southwest Scandinavia, are used for estimation of Holocene vertical land movement and absolute sea level variations in the gateway between the North Sea and the Baltic Sea. Two previous independent studies conducted in the area show that ground penetrating radar reflection images of internal beach ridge and swale architecture form a strong basis for estimation of relative sea level variation. Sediments are dated using optically stimulated luminescence (OSL); this shows that the beach ridges and swales were last exposed to daylight between ~6500 and 0 years ago. Time periods with characteristic changes in the rate of relative sea level change are identified at different localities. The observed relative sea level change rates differ in the study area, mainly because the different localities have experienced different isostatic rebound since the latest glaciation. Variations in uplift rates and absolute sea level change for the region are estimated by inversion of the observed relative sea level changes. The values obtained for the different time periods put constraints on absolute sea level variation during the Holocene and have implications for our understanding of the lithosphere's temporal response to the unloading caused by melting of the thick ice sheet formed during the latest glaciation in Scandinavia.

  7. Mangrove sedimentation and response to relative sea-level rise

    USGS Publications Warehouse

    Woodroffe, CD; Rogers, K.; Mckee, Karen L.; Lovelock, CE; Mendelssohn, IA; Saintilan, N.

    2016-01-01

    Mangroves occur on upper intertidal shorelines in the tropics and subtropics. Complex hydrodynamic and salinity conditions influence mangrove distributions, primarily related to elevation and hydroperiod; this review considers how these adjust through time. Accumulation rates of allochthonous and autochthonous sediment, both inorganic and organic, vary between and within different settings. Abundant terrigenous sediment can form dynamic mudbanks; tides redistribute sediment, contrasting with mangrove peat in sediment-starved carbonate settings. Sediments underlying mangroves sequester carbon, but also contain paleoenvironmental records of adjustments to past sea-level changes. Radiometric dating indicates long-term sedimentation, whereas Surface Elevation Table-Marker Horizon measurements (SET-MH) provide shorter perspectives, indicating shallow subsurface processes of root growth and substrate autocompaction. Many tropical deltas also experience deep subsidence, which augments relative sea-level rise. The persistence of mangroves implies an ability to cope with moderately high rates of relative sea-level rise. However, many human pressures threaten mangroves, resulting in continuing decline in their extent throughout the tropics.

  8. Mangrove Sedimentation and Response to Relative Sea-Level Rise.

    PubMed

    Woodroffe, C D; Rogers, K; McKee, K L; Lovelock, C E; Mendelssohn, I A; Saintilan, N

    2016-01-01

    Mangroves occur on upper intertidal shorelines in the tropics and subtropics. Complex hydrodynamic and salinity conditions, related primarily to elevation and hydroperiod, influence mangrove distributions; this review considers how these distributions change over time. Accumulation rates of allochthonous and autochthonous sediment, both inorganic and organic, vary between and within different settings. Abundant terrigenous sediment can form dynamic mudbanks, and tides redistribute sediment, contrasting with mangrove peat in sediment-starved carbonate settings. Sediments underlying mangroves sequester carbon but also contain paleoenvironmental records of adjustments to past sea-level changes. Radiometric dating indicates long-term sedimentation, whereas measurements made using surface elevation tables and marker horizons provide shorter perspectives, indicating shallow subsurface processes of root growth and substrate autocompaction. Many tropical deltas also experience deep subsidence, which augments relative sea-level rise. The persistence of mangroves implies an ability to cope with moderately high rates of relative sea-level rise. However, many human pressures threaten mangroves, resulting in a continuing decline in their extent throughout the tropics.

  9. Mangrove Sedimentation and Response to Relative Sea-Level Rise

    NASA Astrophysics Data System (ADS)

    Woodroffe, C. D.; Rogers, K.; McKee, K. L.; Lovelock, C. E.; Mendelssohn, I. A.; Saintilan, N.

    2016-01-01

    Mangroves occur on upper intertidal shorelines in the tropics and subtropics. Complex hydrodynamic and salinity conditions, related primarily to elevation and hydroperiod, influence mangrove distributions; this review considers how these distributions change over time. Accumulation rates of allochthonous and autochthonous sediment, both inorganic and organic, vary between and within different settings. Abundant terrigenous sediment can form dynamic mudbanks, and tides redistribute sediment, contrasting with mangrove peat in sediment-starved carbonate settings. Sediments underlying mangroves sequester carbon but also contain paleoenvironmental records of adjustments to past sea-level changes. Radiometric dating indicates long-term sedimentation, whereas measurements made using surface elevation tables and marker horizons provide shorter perspectives, indicating shallow subsurface processes of root growth and substrate autocompaction. Many tropical deltas also experience deep subsidence, which augments relative sea-level rise. The persistence of mangroves implies an ability to cope with moderately high rates of relative sea-level rise. However, many human pressures threaten mangroves, resulting in a continuing decline in their extent throughout the tropics. *

  10. Sea-surface salinity: the missing measurement

    NASA Astrophysics Data System (ADS)

    Stocker, Erich F.; Koblinsky, Chester

    2003-04-01

    Even the youngest child knows that the sea is salty. Yet, routine, global information about the degree of saltiness and the distribution of the salinity is not available. Indeed, the sea surface salinity measurement is a key missing measurement in global change research. Salinity influences circulation and links the ocean to global change and the water-cycle. Space-based remote sensing of important global change ocean parameters such as sea-surface temperature and water-cycle parameters such as precipitation have been available to the research community but a space-based global sensing of salinity has been missing. In July 2002, the National Aeronautical and Space Administration (NASA) announced that the Aquarius mission, focused on the global measurement of sea surface salinity, is one of the missions approved under its ESSP-3 program. Aquarius will begin a risk-reduction phase during 2003. Aquarius will carry a multi-beam 1.4 GHz (L-band) radiometer used for retrieving salinity. It also will carry a 1.2 GHz (L-band) scatterometer used for measuring surface roughness. Aquarius is tentatively scheduled for a 2006 launch into an 8-day Sun-synchronous orbit. Aquarius key science data product will be a monthly, global surface salinity map at 100 km resolution with an accuracy of 0.2 practical salinity units. Aquarius will have a 3 year operational period. Among other things, global salinity data will permit estimates of sea surface density, or buoyancy, that drives the ocean's three-dimensional circulation.

  11. Detecting anthropogenic footprints in sea level rise

    PubMed Central

    Dangendorf, Sönke; Marcos, Marta; Müller, Alfred; Zorita, Eduardo; Riva, Riccardo; Berk, Kevin; Jensen, Jürgen

    2015-01-01

    While there is scientific consensus that global and local mean sea level (GMSL and LMSL) has risen since the late nineteenth century, the relative contribution of natural and anthropogenic forcing remains unclear. Here we provide a probabilistic upper range of long-term persistent natural GMSL/LMSL variability (P=0.99), which in turn, determines the minimum/maximum anthropogenic contribution since 1900. To account for different spectral characteristics of various contributing processes, we separate LMSL into two components: a slowly varying volumetric component and a more rapidly changing atmospheric component. We find that the persistence of slow natural volumetric changes is underestimated in records where transient atmospheric processes dominate the spectrum. This leads to a local underestimation of possible natural trends of up to ∼1 mm per year erroneously enhancing the significance of anthropogenic footprints. The GMSL, however, remains unaffected by such biases. On the basis of a model assessment of the separate components, we conclude that it is virtually certain (P=0.99) that at least 45% of the observed increase in GMSL is of anthropogenic origin. PMID:26220773

  12. Late Holocene sea level changes along the coast of Southwestern Turkey

    NASA Astrophysics Data System (ADS)

    Kızıldaǧ, Nilhan; Özdaş, Harun; Özel, Erdeniz

    2014-05-01

    A multi-disciplinary survey has been performed along the coast of southwestern Turkey in order to determine relative sea level changes during the Late Holocene. Especially, the submergence of harbour structures of the ancient coastal settlements provides noticeable evidence for eustatic sea level rise and/or tectonic subsidence. In addition, the traces of bioerosion produced by some organisms along the limestone coasts formed at mean sea level position represent a remarkable data of paleoshorelines. These traces can be found below the current sea level nowadays due to relative sea level rise. Both archaeological and biological data provide an important source on the amount and period of relative sea level rise along the coasts of southwestern Turkey-southeastern Aegean Sea. This region is under the influence of active tectonism as a result of the collision of the Arab-African and Eurasian plates. Thus, a large number of earthquakes have occurred in this zone which must have been an impact on submergence of ancient harbour structures and geomorphological formations. This area is located very important zone in terms of being tectonically active, having a large number of ancient coastal settlements, and consisting of limestone lithology. A number of submerged archaeological structures and bioerosion formations have been investigated by measuring the depths of remains with respect to the present sea level. By comparing the eustatic sea level change, current elevations and construction time of archaeological remains, which dated taking into account construction techniques and ceramic findings, we determine the amount of relative sea level change. In addition, numerous active faults have been detected by performing seismic survey. The results indicate that the vertical tectonic movement has much more effect on submergence of archaeological and geomorphological features than eustatic sea level rise. Uncovering the role of the tectonic movement and sea level changes on the

  13. Portrait of a Warming Ocean and Rising Sea Levels: Trend of Sea Level Change 1993-2008

    NASA Technical Reports Server (NTRS)

    2008-01-01

    trend also reveals a significant area of rising sea levels in the North Atlantic where sea levels are usually low. This large pool of rapidly rising warm water is evidence of a major change in ocean circulation. It signals a slow down in the sub-polar gyre, a counter-clockwise system of currents that loop between Ireland, Greenland and Newfoundland.

    Such a change could have an impact on climate since the sub-polar gyre may be connected in some way to the nearby global thermohaline circulation, commonly known as the global conveyor belt. This is the slow-moving circulation in which water sinks in the North Atlantic at different locations around the sub-polar gyre, spreads south, travels around the globe, and slowly up-wells to the surface before returning around the southern tip of Africa. Then it winds its way through the surface currents in the Atlantic and eventually comes back to the North Atlantic.

    It is unclear if the weakening of the North Atlantic sub-polar gyre is part of a natural cycle or related to global warming.

    This image was made possible by the detailed record of sea surface height measurements begun by Topex/Poseidon and continued by Jason-1. The recently launched Ocean Surface Topography Mission on the Jason-2 satellite (OSTM/Jason-2) will soon take over this responsibility from Jason-1. The older satellite will move alongside OSTM/Jason-2 and continue to measure sea surface height on an adjacent ground track for as long as it is in good health.

    Topex/Poseidon and Jason-1 are joint missions of NASA and the French space agency, CNES. OSTM/Jason-2 is collaboration between NASA; the National Oceanic and Atmospheric Administration; CNES; and the European Organisation for the Exploitation of Meteorological Satellites. JPL manages the U.S. portion of the missions for NASA's Science Mission Directorate, Washington, D.C.

  14. Numerical study of the Azov Sea level seiche oscillations

    NASA Astrophysics Data System (ADS)

    Matishov, G. G.; Inzhebeikin, Yu. I.

    2009-08-01

    Seiche oscillations of the Azov Sea level are studied on the basis of the developed two-dimensional numerical hydrodynamic model grounded on the shallow water theory and recent data on the morphometric characteristics of the Sea of Azov. Frequency and spatial characteristics of the first five modes corresponding to seiche oscillations of the Azov Sea level are computed. It is shown that the frequency and spatial characteristics of the first five modes obtained for the Sea of Azov level changes correspond to seiche oscillations. The calculated parameters are compared with the field observations, which show their realistic character.

  15. A search for scale in sea-level studies

    USGS Publications Warehouse

    Larsen, C.E.; Clark, I.

    2006-01-01

    Many researchers assume a proportional relationship among the atmospheric CO2 concentration, temperature, and sea level. Thus, the rate of sea-level rise should increase in concert with the documented exponential increase in CO2. Although sea surface temperature has increased in places over the past century and short-term sea level rose abruptly during the 1990s, it is difficult to demonstrate a proportional relationship using existing geologic or historic records. Tide gauge records in the United States cover too short a time interval to verify acceleration in the rate of sea-level rise, although multicentury tide gauge and staff records from the Netherlands and Sweden suggest a mid-19th-century acceleration in sea-level rise. Reconstructions of sea-level changes for the past 1000 years derived using benthic foraminifer data from salt marshes along the East Coast of the United States suggest an increased rate of relative sea-level rise beginning in the 1600s. Geologic records of relative sea-level rise for the past 6000 years are available for several sites along the US East Coast from 14C-dated basal peat below salt marshes and estuarine sediments. When these three scales of sea-level variation are integrated, adjusted for postglacial isostatic movement, and replotted, the range of variation in sea level suggested by basal peat ages is within ??1 meter of the long-term trend. The reconstruction from Long Island Sound data shows a linear rise in sea level beginning in the mid-1600s at a rate consistent with the historic record of mean high water. Long-term tide gauge records from Europe and North America show similar trends since the mid-19th century. There is no clear proportional exponential increase in the rate of sea-level rise. If proportionality exists among sea level, atmospheric CO2, and temperature, there may be a significant time lag before an anthropogenic increase in the rate of sea-level rise occurs.

  16. Impact of sea-level rise on sea water intrusion in coastal aquifers.

    PubMed

    Werner, Adrian D; Simmons, Craig T

    2009-01-01

    Despite its purported importance, previous studies of the influence of sea-level rise on coastal aquifers have focused on specific sites, and a generalized systematic analysis of the general case of the sea water intrusion response to sea-level rise has not been reported. In this study, a simple conceptual framework is used to provide a first-order assessment of sea water intrusion changes in coastal unconfined aquifers in response to sea-level rise. Two conceptual models are tested: (1) flux-controlled systems, in which ground water discharge to the sea is persistent despite changes in sea level, and (2) head-controlled systems, whereby ground water abstractions or surface features maintain the head condition in the aquifer despite sea-level changes. The conceptualization assumes steady-state conditions, a sharp interface sea water-fresh water transition zone, homogeneous and isotropic aquifer properties, and constant recharge. In the case of constant flux conditions, the upper limit for sea water intrusion due to sea-level rise (up to 1.5 m is tested) is no greater than 50 m for typical values of recharge, hydraulic conductivity, and aquifer depth. This is in striking contrast to the constant head cases, in which the magnitude of salt water toe migration is on the order of hundreds of meters to several kilometers for the same sea-level rise. This study has highlighted the importance of inland boundary conditions on the sea-level rise impact. It identifies combinations of hydrogeologic parameters that control whether large or small salt water toe migration will occur for any given change in a hydrogeologic variable.

  17. Sea-level variability in the Mediterranean Sea from altimetry and tide gauges

    NASA Astrophysics Data System (ADS)

    Bonaduce, A.; Pinardi, N.; Oddo, P.; Spada, G.; Larnicol, G.

    2016-11-01

    Sea-level variability in the Mediterranean Sea was investigated by means of in-situ (tide-gauge) and satellite altimetry data over a period spanning two decades (from 1993 to 2012). The paper details the sea-level variations during this time period retrieved from the two data sets. Mean sea-level (MSL) estimates obtained from tide-gauge data showed root mean square differences (RMSDs) in the order of 40-50 % of the variance of the MSL signal estimated from satellite altimetry data, with a dependency on the number and quality of the in-situ data considered. Considering the individual time-series, the results showed that coastal tide-gauge and satellite sea-level signals are comparable, with RMSDs that range between 2.5 and 5 cm and correlation coefficients up to the order of 0.8. A coherence analysis and power spectra comparison showed that two signals have a very similar energetic content at semi-annual temporal scales and below, while a phase drift was observed at higher frequencies. Positive sea-level linear trends for the analysis period were estimated for both the mean sea-level and the coastal stations. From 1993 to 2012, the mean sea-level trend (2.44± 0.5 mm year^{-1}) was found to be affected by the positive anomalies of 2010 and 2011, which were observed in all the cases analysed and were mainly distributed in the eastern part of the basin. Ensemble empirical mode decomposition showed that these events were related to the processes that have dominant periodicities of ˜10 years, and positive residual sea-level trend were generally observed in both data-sets. In terms of mean sea-level trends, a significant positive sea-level trend (>95 %) in the Mediterranean Sea was found on the basis of at least 15 years of data.

  18. Sea-level variability in the Mediterranean Sea from altimetry and tide gauges

    NASA Astrophysics Data System (ADS)

    Bonaduce, Antonio; Pinardi, Nadia; Oddo, Paolo; Spada, Giorgio; Larnicol, Gilles

    2016-04-01

    Sea-level variability in the Mediterranean Sea was investigated by means of in-situ (tide-gauge) and satellite altimetry data over a period spanning two decades (from 1993 to 2012). The paper details the sea-level variations during this time period retrieved from the two data sets. Mean sea-level (MSL) estimates obtained from tide-gauge data showed root mean square differences (RMSDs) in the order of 40-50 % of the variance of the MSL signal estimated from satellite altimetry data, with a dependency on the number and quality of the in-situ data considered. Considering the individual time-series, the results showed that coastal tide-gauge and satellite sea-level signals are comparable, with RMSDs that range between 2.5 and 5 cm and correlation coefficients up to the order of 0.8. A coherence analysis and power spectra comparison showed that two signals have a very similar energetic content at semi-annual temporal scales and below, while a phase drift was observed at higher frequencies. Positive sea-level linear trends for the analysis period were estimated for both the mean sea-level and the coastal stations. From 1993 to 2012, the mean sea-level trend (2.44 ± 0.5 mm yr-1) was found to be affected by the positive anomalies of 2010 and 2011, which were observed in all the cases analysed and were mainly distributed in the eastern part of the basin. Ensemble Empirical Mode Decomposition (EEMD) showed that these events were related to the processes that have dominant periodicities of ˜10 years, and positive residual sea-level trend were generally observed in both data-sets. In terms of mean sea-level trends, a significant positive sea-level trend (> 95 %) in the Mediterranean Sea was found on the basis of at least 15 years of data.

  19. Late Holocene sea-level change in Arctic Norway

    NASA Astrophysics Data System (ADS)

    Barnett, Robert L.; Gehrels, W. Roland; Charman, Dan J.; Saher, Margot H.; Marshall, William A.

    2015-01-01

    Relative sea-level data from the pre-industrial era are required for validating geophysical models of glacio-isostatic adjustment as well as for testing models used to make sea-level predictions based on future climate change scenarios. We present the first late Holocene (past ˜3300 years) relative sea-level reconstruction for northwestern Norway based on investigations in South Hinnøya in the Vesterålen - Lofoton archipelago. Sea-level changes are reconstructed from analyses of salt-marsh and estuarine sediments and the micro-organisms (foraminifera and testate amoebae) preserved within. The 'indicative meaning' of the microfauna is established from their modern distributions. Records are dated by radiocarbon, 201Pb, 137Cs and chemostratigraphical analyses. Our results show a continuous relative sea-level decline of 0.7-0.9 mm yr-1 for South Hinnøya during the late Holocene. The reconstruction extends the relative sea-level trend recorded by local tide gauge data which is only available for the past ˜25 years. Our reconstruction demonstrates that existing models of shoreline elevations and GIA overpredict sea-level positions during the late Holocene. We suggest that models might be adjusted in order to reconcile modelled and reconstructed sea-level changes and ultimately improve understanding of GIA in Fennoscandia.

  20. Uncertainties in sea level reconstructions due to GIA corrections

    NASA Astrophysics Data System (ADS)

    Jevrejeva, S.; Moore, J. C.; Grinsted, A.

    2012-12-01

    We use 1277 tide gauge records since 1807 to compose a global sea level reconstruction and analyse the evolution of sea level trend and acceleration. There is a good agreement between the rate of sea level rise (3.2 mm/yr) calculated from satellite altimetry and the rate of 3.1 mm/yr from tide gauge based reconstruction for the overlapping time period (1993-2009). The new reconstruction suggests a linear trend of 1.9 mm/yr during the 20th century, with only 1.5 mm/yr since 1960. Regional linear trends for 14 ocean basins since 1960 show the fastest sea level rise for the Arctic (3.8 mm/yr), Antarctica (3.5 mm/yr) and North West Pacific region (3.3 mm/yr). Choice of GIA correction is critical in the trends for the local and regional sea level, introducing up to 6 mm/yr uncertainties for individual tide gauge records, up to 2 mm/yr for regional curves and up to 0.8 mm/yr in global sea level reconstruction. We calculate an acceleration of 0.02 mm/yr in global sea level (1807-2010). In comparison the steric component of sea level shows and acceleration of 0.006 mm/yr 2 and mass loss of glaciers accelerates at 0. 003 mm/yr2 over 200 year long time series.

  1. Glacial Isostatic Adjustment and Contemporary Sea Level Rise: An Overview

    NASA Astrophysics Data System (ADS)

    Spada, Giorgio

    2017-01-01

    Glacial isostatic adjustment (GIA) encompasses a suite of geophysical phenomena accompanying the waxing and waning of continental-scale ice sheets. These involve the solid Earth, the oceans and the cryosphere both on short (decade to century) and on long (millennia) timescales. In the framework of contemporary sea-level change, the role of GIA is particular. In fact, among the processes significantly contributing to contemporary sea-level change, GIA is the only one for which deformational, gravitational and rotational effects are simultaneously operating, and for which the rheology of the solid Earth is essential. Here, I review the basic elements of the GIA theory, emphasizing the connections with current sea-level changes observed by tide gauges and altimetry. This purpose is met discussing the nature of the "sea-level equation" (SLE), which represents the basis for modeling the sea-level variations of glacial isostatic origin, also giving access to a full set of geodetic variations associated with GIA. Here, the SLE is employed to characterize the remarkable geographical variability of the GIA-induced sea-level variations, which are often expressed in terms of "fingerprints". Using harmonic analysis, the spatial variability of the GIA fingerprints is compared to that of other components of contemporary sea-level change. In closing, some attention is devoted to the importance of the "GIA corrections" in the context of modern sea-level observations, based on tide gauges or satellite altimeters.

  2. Does Sea Level Change when a Floating Iceberg Melts?

    ERIC Educational Resources Information Center

    Lan, Boon Leong

    2010-01-01

    On the answer page to a recent "Figuring Physics" question, the cute mouse asks another question: "Does the [sea] water level change if the iceberg melts?" The conventional answer is "no." However, in this paper I will show through a simple analysis involving Archimedes' principle that the sea level will rise. The analysis shows the wrong…

  3. Arctic Sea Level During the Satellite Altimetry Era

    NASA Astrophysics Data System (ADS)

    Carret, A.; Johannessen, J. A.; Andersen, O. B.; Ablain, M.; Prandi, P.; Blazquez, A.; Cazenave, A.

    2016-11-01

    Results of the sea-level budget in the high latitudes (up to 80°N) and the Arctic Ocean during the satellite altimetry era. We investigate the closure of the sea-level budget since 2002 using two altimetry sea-level datasets based on the Envisat waveform retracking: temperature and salinity data from the ORAP5 reanalysis, and Gravity Recovery And Climate Experiment (GRACE) space gravimetry data to estimate the steric and mass components. Regional sea-level trends seen in the altimetry map, in particular over the Beaufort Gyre and along the eastern coast of Greenland, are of halosteric origin. However, in terms of regional average over the region ranging from 66°N to 80°N, the steric component contributes little to the observed sea-level trend, suggesting a dominant mass contribution in the Arctic region. This is confirmed by GRACE-based ocean mass time series that agree well with the altimetry-based sea-level time series. Direct estimate of the mass component is not possible prior to GRACE. Thus, we estimated the mass contribution from the difference between the altimetry-based sea level and the steric component. We also investigate the coastal sea level with tide gauge records. Twenty coupled climate models from the CMIP5 project are also used. The models lead us to the same conclusions concerning the halosteric origin of the trend patterns.

  4. Glacial Isostatic Adjustment and Contemporary Sea Level Rise: An Overview

    NASA Astrophysics Data System (ADS)

    Spada, Giorgio

    2016-08-01

    Glacial isostatic adjustment (GIA) encompasses a suite of geophysical phenomena accompanying the waxing and waning of continental-scale ice sheets. These involve the solid Earth, the oceans and the cryosphere both on short (decade to century) and on long (millennia) timescales. In the framework of contemporary sea-level change, the role of GIA is particular. In fact, among the processes significantly contributing to contemporary sea-level change, GIA is the only one for which deformational, gravitational and rotational effects are simultaneously operating, and for which the rheology of the solid Earth is essential. Here, I review the basic elements of the GIA theory, emphasizing the connections with current sea-level changes observed by tide gauges and altimetry. This purpose is met discussing the nature of the "sea-level equation" (SLE), which represents the basis for modeling the sea-level variations of glacial isostatic origin, also giving access to a full set of geodetic variations associated with GIA. Here, the SLE is employed to characterize the remarkable geographical variability of the GIA-induced sea-level variations, which are often expressed in terms of "fingerprints". Using harmonic analysis, the spatial variability of the GIA fingerprints is compared to that of other components of contemporary sea-level change. In closing, some attention is devoted to the importance of the "GIA corrections" in the context of modern sea-level observations, based on tide gauges or satellite altimeters.

  5. Arctic Sea Level During the Satellite Altimetry Era

    NASA Astrophysics Data System (ADS)

    Carret, A.; Johannessen, J. A.; Andersen, O. B.; Ablain, M.; Prandi, P.; Blazquez, A.; Cazenave, A.

    2017-01-01

    Results of the sea-level budget in the high latitudes (up to 80°N) and the Arctic Ocean during the satellite altimetry era. We investigate the closure of the sea-level budget since 2002 using two altimetry sea-level datasets based on the Envisat waveform retracking: temperature and salinity data from the ORAP5 reanalysis, and Gravity Recovery And Climate Experiment (GRACE) space gravimetry data to estimate the steric and mass components. Regional sea-level trends seen in the altimetry map, in particular over the Beaufort Gyre and along the eastern coast of Greenland, are of halosteric origin. However, in terms of regional average over the region ranging from 66°N to 80°N, the steric component contributes little to the observed sea-level trend, suggesting a dominant mass contribution in the Arctic region. This is confirmed by GRACE-based ocean mass time series that agree well with the altimetry-based sea-level time series. Direct estimate of the mass component is not possible prior to GRACE. Thus, we estimated the mass contribution from the difference between the altimetry-based sea level and the steric component. We also investigate the coastal sea level with tide gauge records. Twenty coupled climate models from the CMIP5 project are also used. The models lead us to the same conclusions concerning the halosteric origin of the trend patterns.

  6. Future Extreme Sea Level Variability in the Tropical Pacific

    NASA Astrophysics Data System (ADS)

    Widlansky, M. J.; Timmermann, A.; Stuecker, M. F.; McGregor, S.; Cai, W.; Chikamoto, Y.

    2014-12-01

    During strong El Niño events, sea level drops around tropical western Pacific islands by up to 20-30 cm. Such extreme events (referred to in Samoa as 'taimasa') expose shallow reefs, thereby damaging associated coastal ecosystems and contributing to the formation of 'flat topped coral heads' often referred to as microatolls. We show that during the termination of strong El Niño events, a southward movement of weak trade winds prolongs extreme low sea levels in the southwestern Pacific. Whereas future sea levels are projected to gradually rise, recent modeling evidence suggests that the frequency of strong El Niño events (which alter local trade winds and sea level) is very likely to increase with greenhouse warming. Such changes could exacerbate El Niño-related sea level drops, especially in the tropical southwestern Pacific. Using present-generation coupled climate models forced with increasing greenhouse-gas concentrations, we assess how the interplay between global mean sea level rise, on one hand, and more frequent interannual sea level drops, on the other, will affect future coastal sea levels in the tropical Pacific.

  7. Time of emergence for regional sea-level change

    NASA Astrophysics Data System (ADS)

    Lyu, Kewei; Zhang, Xuebin; Church, John A.; Slangen, Aimée B. A.; Hu, Jianyu

    2014-11-01

    Determining the time when the climate change signal from increasing greenhouse gases exceeds and thus emerges from natural climate variability (referred to as the time of emergence, ToE) is an important climate change issue. Previous ToE studies were mainly focused on atmospheric variables. Here, based on three regional sea-level projection products available to 2100, which have increasing complexity in terms of included processes, we estimate the ToE for sea-level changes relative to the reference period 1986-2005. The dynamic sea level derived from ocean density and circulation changes alone leads to emergence over only limited regions. By adding the global-ocean thermal expansion effect, 50% of the ocean area will show emergence with rising sea level by the early-to-middle 2040s. Including additional contributions from land ice mass loss, land water storage change and glacial isostatic adjustment generally enhances the signal of regional sea-level rise (except in some regions with decreasing total sea levels), which leads to emergence over more than 50% of the ocean area by 2020. The ToE for total sea level is substantially earlier than that for surface air temperature and exhibits little dependence on the emission scenarios, which means that our society will face detectable sea-level change and its potential impacts earlier than surface air warming.

  8. Future extreme sea level seesaws in the tropical Pacific.

    PubMed

    Widlansky, Matthew J; Timmermann, Axel; Cai, Wenju

    2015-09-01

    Global mean sea levels are projected to gradually rise in response to greenhouse warming. However, on shorter time scales, modes of natural climate variability in the Pacific, such as the El Niño-Southern Oscillation (ENSO), can affect regional sea level variability and extremes, with considerable impacts on coastal ecosystems and island nations. How these shorter-term sea level fluctuations will change in association with a projected increase in extreme El Niño and its atmospheric variability remains unknown. Using present-generation coupled climate models forced with increasing greenhouse gas concentrations and subtracting the effect of global mean sea level rise, we find that climate change will enhance El Niño-related sea level extremes, especially in the tropical southwestern Pacific, where very low sea level events, locally known as Taimasa, are projected to double in occurrence. Additionally, and throughout the tropical Pacific, prolonged interannual sea level inundations are also found to become more likely with greenhouse warming and increased frequency of extreme La Niña events, thus exacerbating the coastal impacts of the projected global mean sea level rise.

  9. Estuaries May Face Increased Parasitism as Sea Levels Rise

    NASA Astrophysics Data System (ADS)

    Wendel, JoAnna

    2014-12-01

    Invertebrates in estuaries could be at a greater risk of parasitism as climate change causes sea levels to rise. A new paper published 8 December in Proceedings of the National Academy of Sciences of the United States of America (doi:10.1073/pnas.1416747111) describes how rapid sea level rise in the Holocene affected the population of parasitic flatworms called trematodes.

  10. Future extreme sea level seesaws in the tropical Pacific

    PubMed Central

    Widlansky, Matthew J.; Timmermann, Axel; Cai, Wenju

    2015-01-01

    Global mean sea levels are projected to gradually rise in response to greenhouse warming. However, on shorter time scales, modes of natural climate variability in the Pacific, such as the El Niño–Southern Oscillation (ENSO), can affect regional sea level variability and extremes, with considerable impacts on coastal ecosystems and island nations. How these shorter-term sea level fluctuations will change in association with a projected increase in extreme El Niño and its atmospheric variability remains unknown. Using present-generation coupled climate models forced with increasing greenhouse gas concentrations and subtracting the effect of global mean sea level rise, we find that climate change will enhance El Niño–related sea level extremes, especially in the tropical southwestern Pacific, where very low sea level events, locally known as Taimasa, are projected to double in occurrence. Additionally, and throughout the tropical Pacific, prolonged interannual sea level inundations are also found to become more likely with greenhouse warming and increased frequency of extreme La Niña events, thus exacerbating the coastal impacts of the projected global mean sea level rise. PMID:26601272

  11. Comprehensive Measurements of Wind Systems at the Dead Sea

    NASA Astrophysics Data System (ADS)

    Metzger, Jutta; Corsmeier, Ulrich; Kalthoff, Norbert; Wieser, Andreas; Alpert, Pinhas; Lati, Joseph

    2016-04-01

    The Dead Sea is a unique place on earth. It is located at the lowest point of the Jordan Rift valley and its water level is currently at -429 m above mean sea level (amsl). To the West the Judean Mountains (up to 1000 m amsl) and to the East the Moab mountains (up to 1300 m amsl) confine the north-south oriented valley. The whole region is located in a transition zone of semi-arid to arid climate conditions and together with the steep orography, this forms a quite complex and unique environment. The Virtual Institute DEad SEa Research Venue (DESERVE) is an international project funded by the German Helmholtz Association and was established to study coupled atmospheric, hydrological, and lithospheric processes in the changing environment of the Dead Sea. Previous studies showed that the valley's atmosphere is often governed by periodic wind systems (Bitan, 1974), but most of the studies were limited to ground measurements and could therefore not resolve the three dimensional development and evolution of these wind systems. Performed airborne measurements found three distinct layers above the Dead Sea (Levin, 2005). Two layers are directly affected by the Dead Sea and the third is the commonly observed marine boundary layer over Israel. In the framework of DESERVE a field campaign with the mobile observatory KITcube was conducted to study the three dimensional structure of atmospheric processes at the Dead Sea in 2014. The combination of several in-situ and remote sensing instruments allows temporally and spatially high-resolution measurements in an atmospheric volume of about 10x10x10 km3. With this data set, the development and evolution of typical local wind systems, as well as the impact of regional scale wind conditions on the valley's atmosphere could be analyzed. The frequent development of a nocturnal drainage flow with wind velocities of over 10 m s-1, the typical lake breeze during the day, its onset and vertical extension as well as strong downslope winds

  12. A 6,700 years sea-level record based on French Polynesian coral reefs

    NASA Astrophysics Data System (ADS)

    Hallmann, Nadine; Camoin, Gilbert; Eisenhauer, Anton; Vella, Claude; Samankassou, Elias; Botella, Albéric; Milne, Glenn; Fietzke, Jan; Dussouillez, Philippe

    2015-04-01

    Sea-level change during the Mid- to Late Holocene has a similar amplitude to the sea-level rise that is likely to occur before the end of the 21st century providing a unique opportunity to study the coastal response to sea-level change and to reveal an important baseline of natural climate variability prior to the industrial revolution. Mid- to Late Holocene relative sea-level change in French Polynesia was reconstructed using coral reef records from ten islands, which represent ideal settings for accurate sea-level studies because: 1) they can be regarded as tectonically stable during the relevant period (slow subsidence), 2) they are located far from former ice sheets (far-field), 3) they are characterized by a low tidal amplitude, and 4) they cover a wide range of latitudes which produces significantly improved constraints on GIA (Glacial Isostatic Adjustment) model parameters. Absolute U/Th dating of in situ coral colonies and their accurate positioning via GPS RTK (Real Time Kinematic) measurements is crucial for an accurate reconstruction of sea-level change. We focus mainly on the analysis of coral microatolls, which are sensitive low-tide recorders, as their vertical accretion is limited by the mean low water springs level. Growth pattern analysis allows the reconstruction of low-amplitude, high-frequency sea-level changes on centennial to sub-decadal time scales. A sea-level rise of less than 1 m is recorded between 6 and 3-3.5 ka, and is followed by a gradual fall in sea level that started around 2.5 ka and persisted until the past few centuries. The reconstructed sea-level curve therefore extends the Tahiti sea-level curve [Deschamps et al., 2012, Nature, 483, 559-564], and is in good agreement with a geophysical model tuned to fit far-field deglacial records [Bassett et al., 2005, Science, 309, 925-928].

  13. Sea level data and techniques for detecting vertical crustal movements

    NASA Technical Reports Server (NTRS)

    Lennon, G. W.

    1978-01-01

    An attempt is made to survey problems, requirements, and the outlook for the future in the study of sea level time series so as to determine the relative movement of land and sea levels. The basic aim is to eliminate from the record the contributions from whatever marine dynamic phenomena respond to treatment, allowing the secular element to be identified with optimum clarity. Nevertheless the concept of sea level perturbation varies according to regional experience. The recent work of the Permanent Service for Mean Sea Level helps to eliminate geodetic noise from the series and makes it possible, perhaps, to treat the global mean sea level data bank so as to define eustatic changes in ocean volume which, in the present context, may be regarded as the final goal, allowing the identification of vertical crustal motion itself.

  14. Eustatic sea level fluctuations induced by polar wander

    NASA Technical Reports Server (NTRS)

    Sabadini, Roberto; Doglioni, Carlo; Yuen, David A.

    1990-01-01

    It is shown here that polar wander of a viscoelastic, stratified earth can induce global sea level fluctuations comparable to the short-term component in eustatic sea-level curves. The sign of these fluctuations, which are very sensitive to the rheological stratification, depends on the geographical location of the observation point; rises and falls in sea level can thus be coeval in different parts of the world. This finding is a distinct contrast to the main assumption underlying the reconstruction of eustatic curves, namely that global sea-level events produce the same depositional sequence everywhere. It is proposed that polar wander should be added to the list of geophysical mechanisms that can control the third-order cycles in sea level.

  15. Continuous assimilation of simulated Geosat altimetric sea level into an eddy-resolving numerical ocean model. I - Sea level differences. II - Referenced sea level differences

    NASA Technical Reports Server (NTRS)

    White, Warren B.; Tai, Chang-Kou; Holland, William R.

    1990-01-01

    The optimal interpolation method of Lorenc (1981) was used to conduct continuous assimilation of altimetric sea level differences from the simulated Geosat exact repeat mission (ERM) into a three-layer quasi-geostrophic eddy-resolving numerical ocean box model that simulates the statistics of mesoscale eddy activity in the western North Pacific. Assimilation was conducted continuously as the Geosat tracks appeared in simulated real time/space, with each track repeating every 17 days, but occurring at different times and locations within the 17-day period, as would have occurred in a realistic nowcast situation. This interpolation method was also used to conduct the assimilation of referenced altimetric sea level differences into the same model, performing the referencing of altimetric sea sevel differences by using the simulated sea level. The results of this dynamical interpolation procedure are compared with those of a statistical (i.e., optimum) interpolation procedure.

  16. Sound Level Measurements

    DTIC Science & Technology

    2011-08-01

    2.2.2.2 Transducer Applications. a. For measurements above 40 kPa (186 dB), pointed or disc -shaped piezoelectric or piezoresistive probes with...speed increments from slow to maximum. TOP 01-2-608A 1 August 2011 12 (3) Record dBA, and an octave-band analysis at each microphone...compartment and record the dBA and octave-band analysis for the condition-of-vessel operation that produces the most noise. (4) When cargo

  17. The Impact of Groundwater Depletion on Spatial Variations in Sea Level Change During the Past Century

    NASA Astrophysics Data System (ADS)

    Conrad, C. P.; Veit, E.; Natarov, S.

    2015-12-01

    The loss of continental groundwater to the oceans during the past century has elevated sea level by ~25(±5) mm, and has caused ~0.7mm/yr of sea level rise since 2005. The mass unloading associated with this groundwater depletion induces elastic uplift of Earth's solid surface and depresses the gravitational equipotential surface that defines sea level. Together, these deflections should cause slower relative sea level rise near areas of continental groundwater loss. We estimated these variations in sea level change using a model of the solid Earth's response to estimates of groundwater depletion during the past century. We find large negative deviations in relative sea level near California, Western India, the western Yellow Sea and the eastern Mediterranean Sea. Relative sea level measured by tide gauges in these areas show slower sea level rise rates compared to global averages. For example, on the western coast of India (e.g., Karachi), groundwater-induced deviations from global average sea level rise can exceed -40 mm, and our model predicts ~1 mm/yr of sea level drop since 2005. Correcting tide gauge records for groundwater depletion using our model improves their fit to the global trend estimated by Church & White (2011), and further reduces the variation of rise rates observed among regional groups of stations. We reconstructed Global Mean Sea Level (GMSL) between 1930 and 2009 taking in account groundwater depletion corrections determined from our model. We found that including groundwater depletion increases our estimate of the global rate of change of GMSL from 1.81 to 1.88 mm/yr during this time period because the observed rise at some key stations is slowed by nearby groundwater depletion. For the past 20 years, including groundwater depletion increases GMSL from 3.32mm/yr to 3.46mm/yr. Quantifying the spatial variability of sea level associated with groundwater depletion is important for understanding the variety of factors that affect sea level, and

  18. Holocene sea level variations on the basis of integration of independent data sets

    SciTech Connect

    Sahagian, D.; Berkman, P. . Dept. of Geological Sciences and Byrd Polar Research Center)

    1992-01-01

    Variations in sea level through earth history have occurred at a wide variety of time scales. Sea level researchers have attacked the problem of measuring these sea level changes through a variety of approaches, each relevant only to the time scale in question, and usually only relevant to the specific locality from which a specific type of data are derived. There is a plethora of different data types that can and have been used (locally) for the measurement of Holocene sea level variations. The problem of merging different data sets for the purpose of constructing a global eustatic sea level curve for the Holocene has not previously been adequately addressed. The authors direct the efforts to that end. Numerous studies have been published regarding Holocene sea level changes. These have involved exposed fossil reef elevations, elevation of tidal deltas, elevation of depth of intertidal peat deposits, caves, tree rings, ice cores, moraines, eolian dune ridges, marine-cut terrace elevations, marine carbonate species, tide gauges, and lake level variations. Each of these data sets is based on particular set of assumptions, and is valid for a specific set of environments. In order to obtain the most accurate possible sea level curve for the Holocene, these data sets must be merged so that local and other influences can be filtered out of each data set. Since each data set involves very different measurements, each is scaled in order to define the sensitivity of the proxy measurement parameter to sea level, including error bounds. This effectively determines the temporal and spatial resolution of each data set. The level of independence of data sets is also quantified, in order to rule out the possibility of a common non-eustatic factor affecting more than one variety of data. The Holocene sea level curve is considered to be independent of other factors affecting the proxy data, and is taken to represent the relation between global ocean water and basin volumes.

  19. Investigations at regional scales of reconstruct sea level variability over the past 50 years

    NASA Astrophysics Data System (ADS)

    Becker, M.; Meyssignac, B.; Llovel, W.; Cazenave, A. A.; Rogel, P.

    2010-12-01

    Sea level rise is a major consequence of global warming, which threatens many low-lying, highly populated coastal regions of the world. In such regions, sea level rise amplifies other stresses due to natural phenomena (e.g., sediment load-induced ground subsidence in deltaic areas, vertical ground motions due to tectonics, volcanism and post-glacial rebound, etc.) or human activities (e.g., ground subsidence due to ground water pumping and/or oil extraction, urbanisation, etc.). Observations for the recent decades from tide gauges and satellite altimetry show that sea level rise is far from being geographically uniform. Here we present an analysis of decadal / multi-decadal sea level variations in a number of selected regions: Tropical Pacific, Indian Ocean, Gulf of Mexico and Caribbean region. For that purpose, we use a reconstruction of past sea level -last 50 years- based on the joint statistical analysis of tide gauge records and gridded sea level from an ocean circulation model. We highlight the sea level trends over the past 50 years in each region. Comparison between reconstructed sea-level trends with tide gauge records at sites not included in the reconstruction shows general good agreement, suggesting that regional trend patterns infer from the reconstruction are realistic (in addition, reconstructed sea-level agrees well with altimeter measurements since 1993). We find above-global average sea level rise since 1950 at several islands in the Eastern Tropical Pacific (Funafuti, Samoa, Kiribati, Cook Islands). Empirical Orthogonal Function (EOF) analyses are performed for each region to describe accurately the spatio-temporal interannual variability. We also compute spatial trend patterns in thermal expansion to determine which part of the observed regional sea level variability can be attributed to change in ocean temperature.

  20. Assessment of groundwater inundation as consequence of sea-level rise

    NASA Astrophysics Data System (ADS)

    Rotzoll, K.; Fletcher, C. H.

    2012-12-01

    Strong evidence on climate change underscores the need for actions to reduce the impacts of sea-level rise. It has been largely unrecognized that low-lying coastal areas are more vulnerable to inundation from groundwater than marine flooding because the groundwater elevation is typically higher than mean sea level. Field measurements of the coastal groundwater elevation and tidal influence in urban Honolulu, Hawaii, allow estimates of the generalized distribution of the mean water table, which was used in conjunction with digital elevation maps to assess vulnerability to groundwater inundation from sea-level rise. We find that 0.6 m of potential sea-level rise causes substantial flooding, and 1 m sea-level rise inundates 10% of a 1-km wide coastal zone. This has wide-reaching consequences for decision-makers, resource managers, and urban planners and is applicable to many low-lying coastal areas.

  1. Sea Level Trend and Variability in the Straits of Singapore and Malacca

    NASA Astrophysics Data System (ADS)

    Luu, Q.; Tkalich, P.

    2013-12-01

    The Straits of Singapore and Malacca (SSM) connect the Andaman Sea located northeast of the Indian Ocean to the South China Sea, the largest marginal sea situated in the tropical Pacific Ocean. Consequently, sea level in the SSM is assumed to be governed by various regional phenomena associated with the adjacent parts of Indian and Pacific Oceans. At annual scale sea level variability is dominant by the Asian monsoon. Interannual sea level signals are modulated by the El Niño-Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD). In the long term, regional sea level is driven by the global climate change. However, relative impacts of these multi-scale phenomena on regional sea level in the SSM are yet to be quantified. In present study, publicly available tide gauge records and satellite altimetry data are used to derive long-term sea level trend and variability in SSM. We used the data from research-quality stations, including four located in the Singapore Strait (Tanjong Pagar, Raffles Lighthouse, Sultan Shoal and Sembawang) and seven situated in the Malacca Strait (Kelang, Keling, Kukup, Langkawji, Lumut, Penang and Ko Taphao Noi), each one having 25-39 year data up to the year 2011. Harmonic analysis is performed to filter out astronomic tides from the tide gauge records when necessary; and missing data are reconstructed using identified relationships between sea level and the governing phenomena. The obtained sea level anomalies (SLAs) and reconstructed mean sea level are then validated against satellite altimetry data from AVISO. At multi-decadal scale, annual measured sea level in the SSM is varying with global mean sea level, rising for the period 1984-2009 at the rate 1.8-2.3 mm/year in the Singapore Strait and 1.1-2.8 mm/year in the Malacca Strait. Interannual regional sea level drops are associated with El Niño events, while the rises are correlated with La Niña episodes; both variations are in the range of ×5 cm with correlation coefficient

  2. Blending of satellite and tide gauge sea level observations and its assimilation in a storm surge model of the North Sea and Baltic Sea

    NASA Astrophysics Data System (ADS)

    Madsen, Kristine S.; Høyer, Jacob L.; Fu, Weiwei; Donlon, Craig

    2015-09-01

    Coastal storm surge forecasts are typically derived from dedicated hydrodynamic model systems, relying on Numerical Weather Prediction (NWP) inputs. Uncertainty in the NWP wind field affects both the preconditioning and the forecast of sea level. Traditionally, tide gauge data have been used to limit preconditioning errors, providing point information. Here we utilize coastal satellite altimetry sea level observations. Careful processing techniques allow data to be retrieved up to 3 km from the coast, combining 1 Hz and 20 Hz data. The use of satellite altimetry directly is limited to times when the satellite passes over the area of interest. Instead, we use a stationary blending method developed by Madsen et al. (2007) to relate the coastal satellite altimetry with corresponding tide gauge measurements, allowing generation of sea level maps whenever tide gauge data are available. We apply the method in the North Sea and Baltic Sea, including the coastal zone, and test it for operational nowcasting and hindcasting of the sea level. The feasibility to assimilate the blended product into a hydrodynamic model is assessed, using the ensemble optimal interpolation method. A 2 year test simulation shows decreased sea level root mean square error of 7-43% and improved correlation by 1-23% in all modeled areas, when validated against independent tide gauges, indicating the feasibility to limit preconditioning errors for storm surge forecasting, using a relatively cost effective assimilation scheme.

  3. New developments in spatial interpolation methods of Sea-Level Anomalies in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Troupin, Charles; Barth, Alexander; Beckers, Jean-Marie; Pascual, Ananda

    2014-05-01

    The gridding of along-track Sea-Level Anomalies (SLA) measured by a constellation of satellites has numerous applications in oceanography, such as model validation, data assimilation or eddy tracking. Optimal Interpolation (OI) is often the preferred method for this task, as it leads to the lowest expected error and provides an error field associated to the analysed field. However, the numerical cost of the method may limit its utilization in situations where the number of data points is significant. Furthermore, the separation of non-adjacent regions with OI requires adaptation of the code, leading to a further increase of the numerical cost. To solve these issues, the Data-Interpolating Variational Analysis (DIVA), a technique designed to produce gridded from sparse in situ measurements, is applied on SLA data in the Mediterranean Sea. DIVA and OI have been shown to be equivalent (provided some assumptions on the covariances are made). The main difference lies in the covariance function, which is not explicitly formulated in DIVA. The particular spatial and temporal distributions of measurements required adaptation in the Software tool (data format, parameter determinations, ...). These adaptation are presented in the poster. The daily analysed and error fields obtained with this technique are compared with available products such as the gridded field from the Archiving, Validation and Interpretation of Satellite Oceanographic data (AVISO) data server. The comparison reveals an overall good agreement between the products. The time evolution of the mean error field evidences the need of a large number of simultaneous altimetry satellites: in period during which 4 satellites are available, the mean error is on the order of 17.5%, while when only 2 satellites are available, the error exceeds 25%. Finally, we propose the use sea currents to improve the results of the interpolation, especially in the coastal area. These currents can be constructed from the bathymetry

  4. River discharge contribution to sea-level rise in the Yangtze River Estuary, China

    NASA Astrophysics Data System (ADS)

    Kuang, Cuiping; Chen, Wei; Gu, Jie; Su, Tsung-Chow; Song, Hongling; Ma, Yue; Dong, Zhichao

    2017-02-01

    Sea level changes in the Yangtze River Estuary (YRE) as a result of river discharge are investigated based on the monthly averaged river discharge from 1950 to 2011 at the Datong station. Quantification of the sea level contribution is made by model computed results and the sea level rates reported by the China Sea Level Bulletin (CSLB). The coastal modeling tool, MIKE21, is used to establish a depth-averaged hydrodynamic model covering the YRE and Hangzhou Bay. The model is validated with the measured data. Multi-year monthly river discharges are statistically calculated based on the monthly river discharges at Datong station from 1950 to 2011. The four characteristic discharges (frequency of 75%, 50% and 25%, and multi-year monthly) and month-averaged river discharge from 1950 to 2011 are used to study the seasonal and long-term changes of sea level. The computed sea level at the Dajishan and Lvsi stations are used to study the multi-time scale structure of periodic variation in different time scale of river discharge series. The results reveal that (1) the sea level rises as the river discharge increases, and its amplification decreases from upstream to the offshore. (2) The sea level amplification on the south coast is greater than that on the north coast. When river discharge increases by 20,000 m3/s, the sea level will increase by 0.005-0.010 m in most of Hangzhou Bay. (3) The sea level at the Dajishan station, influenced by river discharge, increased 0.178 mm/y from 1980 to 2011. Correspondingly, the sea level rose at a rate of 2.6-3.0 mm/y during the same period. These values were provided by the CSLB. The increase in sea level (1980-2011) at the Dajishan station caused by river discharge is 6.8-8.9% of the total increase in sea level. (4) The 19-20 year dominant nodal cycle of sea level at the Dajishan and Lvsi stations is in accord with 18.6 year nodal cycle of main tidal constituents on Chinese coasts. It implies that the sea-level change period on the

  5. Sea-Level Rise Impacts on Hudson River Marshes

    NASA Astrophysics Data System (ADS)

    Hooks, A.; Nitsche, F. O.

    2015-12-01

    The response of tidal marshes to increasing sea-level rise is uncertain. Tidal marshes can adapt to rising sea levels through vertical accretion and inland migration. Yet tidal marshes are vulnerable to submergence if the rate of sea-level rise exceeds the rate of accretion and if inland migration is limited by natural features or development. We studied how Piermont and Iona Island Marsh, two tidal marshes on the Hudson River, New York, would be affected by sea-level rise of 0.5m, 1m, and 1.5m by 2100. This study was based on the 2011-2012 Coastal New York LiDAR survey. Using GIS we mapped sea-level rise projections accounting for accretion rates and calculated the submerged area of the marsh. Based on the Hudson River National Estuarine Research Reserve Vegetation 2005 dataset, we studied how elevation zones based on vegetation distributions would change. To evaluate the potential for inland migration, we assessed land cover around each marsh using the National Land Cover Database 2011 Land Cover dataset and examined the slope beyond the marsh boundaries. With an accretion rate of 0.29cm/year and 0.5m of sea-level rise by 2100, Piermont Marsh would be mostly unchanged. With 1.5m of sea-level rise, 86% of Piermont Marsh would be flooded. For Iona Island Marsh with an accretion rate of 0.78cm/year, sea-level rise of 0.5m by 2100 would result in a 4% expansion while 1.5m sea-level rise would cause inundation of 17% of the marsh. The results indicate that Piermont and Iona Island Marsh may be able to survive rates of sea-level rise such as 0.5m by 2100 through vertical accretion. At rates of sea-level rise like 1.5m by 2100, vertical accretion cannot match sea-level rise, submerging parts of the marshes. High elevations and steep slopes limit Piermont and Iona Island Marsh's ability to migrate inland. Understanding the impacts of sea-level rise on Piermont and Iona Island Marsh allows for long-term planning and could motivate marsh conservation programs.

  6. Holocene sea-level oscillations and environmental changes on the Eastern Black Sea shelf

    USGS Publications Warehouse

    Ivanova, E.V.; Murdmaa, I.O.; Chepalyga, A.L.; Cronin, T. M.; Pasechnik, I.V.; Levchenko, O.V.; Howe, S.S.; Manushkina, A.V.; Platonova, E.A.

    2007-01-01

    A multi-proxy study of four sediment cores from the Eastern (Caucasian) Black Sea shelf revealed five transgressive-regressive cycles overprinted on the general trend of glacioeustatic sea-level rise during the last 11,000??14C yr. These cycles are well represented in micro-and macrofossil assemblages, sedimentation rates, and grain size variations. The oldest recovered sediments were deposited in the Neoeuxinian semi-freshwater basin (??? 10,500-9000??14C yr BP) and contain a Caspian-type mollusk fauna dominated by Dreissena rostriformis. Low ??18O and ??13C values are measured on this species. The first appearance of marine mollusks and ostracodes from the Mediterranean is established in this part of the Black Sea at ??? 8200??14C yr BP, i.e., about 1000-2000??yr later than the appearance of marine microfossils in the deeper part of the sea. The Early Holocene (Bugazian to Vityazevian) condensed section of shell and shelly mud sediments with at least two hiatuses represent a high-energy shelf-edge facies. It contains a transitional assemblage representing a mixture of Caspian and Mediterranean fauna. This pattern suggests a dual-flow regime via the Bosphorus after 8200??14C yr BP. Caspian species disappear and oligohaline species decrease in abundance during the Vityazevian-Prekalamitian cycle. Later, during the Middle to Late Holocene, low sea-level stands are characterized by shell layers, whereas silty mud with various mollusk and ostracode assemblages rapidly accumulated during transgressions. Restricted mud accumulation, as well as benthic faunal composition and abundance, suggest high-energy and well-ventilated bottom water during low sea-level stands. A trend of 18O enrichment in mollusk shells points to an increase in bottom-water salinity during the Vityazevian to Kalamitian transgressions (??? 7000 to 5700??14C yr BP) due to a more open connection with the Mediterranean, while a pronounced increase in polyhaline species abundance is established during

  7. Regional Sea Level Scenarios for Coastal Risk Management: Managing the Uncertainty of Future Sea Level Change and Extreme Water Levels for Department of Defense Coastal Sites Worldwide

    DTIC Science & Technology

    2016-04-01

    SERDP NOAA USACE Ocean MANAGING THE UNCERTAINTY OF FUTURE SEA LEVEL CHANGE AND EXTREME WATER LEVELS FOR DEPARTMENT OF DEFENSE COASTAL SITES...Uncertainty of Future Sea Level Change and Extreme Water Levels for Department of Defense Coastal Sites Worldwide. U.S. Department of Defense...Strategic Environmental Research and Development Program. 224 pp. MANAGING THE UNCERTAINTY OF FUTURE SEA LEVEL CHANGE AND EXTREME WATER LEVELS FOR

  8. Future sea level rise constrained by observations and long-term commitment

    PubMed Central

    Mengel, Matthias; Levermann, Anders; Frieler, Katja; Robinson, Alexander; Marzeion, Ben; Winkelmann, Ricarda

    2016-01-01

    Sea level has been steadily rising over the past century, predominantly due to anthropogenic climate change. The rate of sea level rise will keep increasing with continued global warming, and, even if temperatures are stabilized through the phasing out of greenhouse gas emissions, sea level is still expected to rise for centuries. This will affect coastal areas worldwide, and robust projections are needed to assess mitigation options and guide adaptation measures. Here we combine the equilibrium response of the main sea level rise contributions with their last century's observed contribution to constrain projections of future sea level rise. Our model is calibrated to a set of observations for each contribution, and the observational and climate uncertainties are combined to produce uncertainty ranges for 21st century sea level rise. We project anthropogenic sea level rise of 28–56 cm, 37–77 cm, and 57–131 cm in 2100 for the greenhouse gas concentration scenarios RCP26, RCP45, and RCP85, respectively. Our uncertainty ranges for total sea level rise overlap with the process-based estimates of the Intergovernmental Panel on Climate Change. The “constrained extrapolation” approach generalizes earlier global semiempirical models and may therefore lead to a better understanding of the discrepancies with process-based projections. PMID:26903648

  9. Future sea level rise constrained by observations and long-term commitment.

    PubMed

    Mengel, Matthias; Levermann, Anders; Frieler, Katja; Robinson, Alexander; Marzeion, Ben; Winkelmann, Ricarda

    2016-03-08

    Sea level has been steadily rising over the past century, predominantly due to anthropogenic climate change. The rate of sea level rise will keep increasing with continued global warming, and, even if temperatures are stabilized through the phasing out of greenhouse gas emissions, sea level is still expected to rise for centuries. This will affect coastal areas worldwide, and robust projections are needed to assess mitigation options and guide adaptation measures. Here we combine the equilibrium response of the main sea level rise contributions with their last century's observed contribution to constrain projections of future sea level rise. Our model is calibrated to a set of observations for each contribution, and the observational and climate uncertainties are combined to produce uncertainty ranges for 21st century sea level rise. We project anthropogenic sea level rise of 28-56 cm, 37-77 cm, and 57-131 cm in 2100 for the greenhouse gas concentration scenarios RCP26, RCP45, and RCP85, respectively. Our uncertainty ranges for total sea level rise overlap with the process-based estimates of the Intergovernmental Panel on Climate Change. The "constrained extrapolation" approach generalizes earlier global semiempirical models and may therefore lead to a better understanding of the discrepancies with process-based projections.

  10. Synthetic stratigraphy of epicontinental seas: a carbonate sedimentation model and its applications in sea level studies

    SciTech Connect

    Cisne, J.L.; Gildner, R.F.

    1984-04-01

    Carbonates from the central parts of epicontinental seas are ideal strata for detailed study of eustatic sea level change. On the basis of sedimentation model in which carbonate accumulation rate is directly proportional to water depth, we developed synthetic stratigraphies for sea level histories expected for post-glacial transgression and for constant and sinusoidally fluctuating ocean ridge volume increase. These histories give distinctly different trends for water depth as a function of stratigraphic position in the sections' bathymetric curves. In general, water depth is proportional to the rate of sea level rise. Depth-dependent sedimentation leads to a time lag between sea level fluctuation and corresponding depth fluctuation which, as examples show, can approach 10/sup 6/ years for depth fluctuations of even a few meters--a fundamental consideration for reconstructing sea level curves, time-correlating sections by bathymetric curves, and relating water depth on continents to ocean ridge volume. Bathymetric curves based on gradient analysis of fossil assemblages (coenocorrelation curves) for American Middle Ordovician sections approximate patterns expected for sinusoidally increasing sea level. The model's predictions are tested in an ''artificial experiment'' that takes advantage of differential subsidence between the craton's middle and its edge to make a difference in the bathymetric histories of sections that otherwise record the same sea level history. The depth dependence in sedimentation was that above wave base net accumulation per year was very roughly 3 x 10/sup -6/ of the water depth.

  11. Sea Level Data Archaeology for the Global Sea Level Observing System (GLOSS)

    NASA Astrophysics Data System (ADS)

    Bradshaw, Elizabeth; Matthews, Andy; Rickards, Lesley; Jevrejeva, Svetlana

    2015-04-01

    The Global Sea Level Observing System (GLOSS) was set up in 1985 to collect long term tide gauge observations and has carried out a number of data archaeology activities over the past decade, including sending member organisations questionnaires to report on their repositories. The GLOSS Group of Experts (GLOSS GE) is looking to future developments in sea level data archaeology and will provide its user community with guidance on finding, digitising, quality controlling and distributing historic records. Many records may not be held in organisational archives and may instead by in national libraries, archives and other collections. GLOSS will promote a Citizen Science approach to discovering long term records by providing tools for volunteers to report data. Tide gauge data come in two different formats, charts and hand-written ledgers. Charts are paper analogue records generated by the mechanical instrument driving a pen trace. Several GLOSS members have developed software to automatically digitise these charts and the various methods were reported in a paper on automated techniques for the digitization of archived mareograms, delivered to the GLOSS GE 13th meeting. GLOSS is creating a repository of software for scanning analogue charts. NUNIEAU is the only publically available software for digitising tide gauge charts but other organisations have developed their own tide gauge digitising software that is available internally. There are several other freely available software packages that convert image data to numerical values. GLOSS could coordinate a comparison study of the various different digitising software programs by: Sending the same charts to each organisation and asking everyone to digitise them using their own procedures Comparing the digitised data Providing recommendations to the GLOSS community The other major form of analogue sea level data is handwritten ledgers, which are usually observations of high and low waters, but sometimes contain higher

  12. The Phanerozoic record of global sea-level change.

    PubMed

    Miller, Kenneth G; Kominz, Michelle A; Browning, James V; Wright, James D; Mountain, Gregory S; Katz, Miriam E; Sugarman, Peter J; Cramer, Benjamin S; Christie-Blick, Nicholas; Pekar, Stephen F

    2005-11-25

    We review Phanerozoic sea-level changes [543 million years ago (Ma) to the present] on various time scales and present a new sea-level record for the past 100 million years (My). Long-term sea level peaked at 100 +/- 50 meters during the Cretaceous, implying that ocean-crust production rates were much lower than previously inferred. Sea level mirrors oxygen isotope variations, reflecting ice-volume change on the 10(4)- to 10(6)-year scale, but a link between oxygen isotope and sea level on the 10(7)-year scale must be due to temperature changes that we attribute to tectonically controlled carbon dioxide variations. Sea-level change has influenced phytoplankton evolution, ocean chemistry, and the loci of carbonate, organic carbon, and siliciclastic sediment burial. Over the past 100 My, sea-level changes reflect global climate evolution from a time of ephemeral Antarctic ice sheets (100 to 33 Ma), through a time of large ice sheets primarily in Antarctica (33 to 2.5 Ma), to a world with large Antarctic and large, variable Northern Hemisphere ice sheets (2.5 Ma to the present).

  13. Sea level change: lessons from the geologic record

    USGS Publications Warehouse

    ,

    1995-01-01

    Rising sea level is potentially one of the most serious impacts of climatic change. Even a small sea level rise would have serious economic consequences because it would cause extensive damage to the world's coastal regions. Sea level can rise in the future because the ocean surface can expand due to warming and because polar ice sheets and mountain glaciers can melt, increasing the ocean's volume of water. Today, ice caps on Antarctica and Greenland contain 91 and 8 percent of the world's ice, respectively. The world's mountain glaciers together contain only about 1 percent. Melting all this ice would raise sea level about 80 meters. Although this extreme scenario is not expected, geologists know that sea level can rise and fall rapidly due to changing volume of ice on continents. For example, during the last ice age, about 18,000 years ago, continental ice sheets contained more than double the modem volume of ice. As ice sheets melted, sea level rose 2 to 3 meters per century, and possibly faster during certain times. During periods in which global climate was very warm, polar ice was reduced and sea level was higher than today.

  14. Upper Limit for Sea Level Projections by 2100

    NASA Astrophysics Data System (ADS)

    Jevrejeva, S.; Grinsted, A.; Moore, J. C.

    2014-12-01

    With more than 150 million people living within 1 m of high tide future sea level rise is one of the most damaging aspects of warming climate. The latest Intergovernmental Panel on Climate Change report (AR5 IPCC) noted that a 0.5 m rise in mean sea level will result in a dramatic increase the frequency of high water extremes - by an order of magnitude, or more in some regions. Thus the flood threat to the rapidly growing urban populations and associated infrastructure in coastal areas are major concerns for society. Hence, impact assessment, risk management, adaptation strategy and long-term decision making in coastal areas depend on projections of mean sea level and crucially its low probability, high impact, upper range. We construct the probability density function of global sea level at 2100, estimating that sea level rises larger than 180 cm are less than 5% probable. An upper limit for global sea level rise of 190 cm is assembled by summing the highest estimates of individual sea level rise components simulated by process based models with the RCP8.5 scenario. The agreement between the methods may suggest more confidence than is warranted since large uncertainties remain due to the lack of scenario-dependent projections from ice sheet dynamical models, particularly for mass loss from marine-based fast flowing outlet glaciers in Antarctica.

  15. Upper Limit for Sea Level Projections by 2100

    NASA Astrophysics Data System (ADS)

    Jevrejeva, Svetlana; Grinsted, Aslak; Moore, John

    2015-04-01

    With more than 150 million people living within 1 m of high tide future sea level rise is one of the most damaging aspects of warming climate. The latest Intergovernmental Panel on Climate Change report (AR5 IPCC) noted that a 0.5 m rise in mean sea level will result in a dramatic increase the frequency of high water extremes - by an order of magnitude, or more in some regions. Thus the flood threat to the rapidly growing urban populations and associated infrastructure in coastal areas are major concerns for society. Hence, impact assessment, risk management, adaptation strategy and long-term decision making in coastal areas depend on projections of mean sea level and crucially its low probability, high impact, upper range. We construct the probability density function of global sea level at 2100, estimating that sea level rises larger than 180 cm are less than 5% probable. An upper limit for global sea level rise of 190 cm is assembled by summing the highest estimates of individual sea level rise components simulated by process based models with the RCP8.5 scenario. The agreement between the methods may suggest more confidence than is warranted since large uncertainties remain due to the lack of scenario-dependent projections from ice sheet dynamical models, particularly for mass loss from marine-based fast flowing outlet glaciers in Antarctica.

  16. Subsidence and Relative Sea-level Rise in Threatened Deltas

    NASA Astrophysics Data System (ADS)

    Syvitski, J. P.; Higgins, S.

    2014-12-01

    In determining the risk lowland deltaic topography, as threatened by sea level rise and land subsidence, a number of important processes must be evaluated. Sea level rise is a global process but with local manifestations. Asian deltas have been experiencing higher rates of sea level rise due to the steric impact on dynamic (ocean) topography. Other large scale geophysical impacts on relative sea level at the local scale include the isostatic and flexural response to Holocene sea level history, Holocene sediment loads, and in former ice sheet zones --- glacial rebound. Tectonism does play a role on relative sea level rise, particularly in South America where the Eastern coastline, particularly Argentina, is rising relative to regional sea levels. Subsidence is impacted by both natural ground compaction, and accelerated compaction due to, for example, peat oxidation that often has a human driver (e.g. swamp reclammation). Subsidence is also impacted by the extraction of deeper deposits of petroleum and water. Rates of delta subsidence vary widely, depending on the magnitude of the anthropogenic driver, from a few mm/y to 100's of mm/y. Ground water withdrawal is the dominant reason behind much of the world's coastal subsidence, with important exceptions. On average subsidence rates (all causes) now contribute to local sea level innundations at rates four times faster then sea level is rising. New technologies, particularly InSAR and GPS methods, can often pin point the local cause (e.g. water withdrawl for agriculture versus for aquaculture). Subsurface soil or rock heterogeneity, and other very local geological patterns such as historical river pathways, also influence the temporal and spatial patterns associated with delta subsidence.

  17. Evidence for glacial control of rapid sea level changes in the early cretaceous

    SciTech Connect

    Stoll, H.M.; Schrag, D.P.

    1996-06-21

    Lower Cretaceous bulk carbonate from deep sea sediments records sudden inputs of strontium resulting from the exposure of continental shelves. Strontium data from an interval spanning 7 million years in the Berriasian-Valanginian imply that global sea level fluctuated about 50 meters over time scales of 200,000 to 500,000 years, which is in agreement with the Exxon sea level curve. Oxygen isotope measurements indicate that the growth of continental ice sheets caused these rapid sea level changes. If glaciation caused all the rapid sea level changes in the cretaceous that are indicated by the Exxon curve, then an Antarctic ice sheet may have existed despite overall climatic warmth. 30 refs., 1 fig.

  18. An alternative to reduction of surface pressure to sea level

    NASA Technical Reports Server (NTRS)

    Deardorff, J. W.

    1982-01-01

    The pitfalls of the present method of reducing surface pressure to sea level are reviewed, and an alternative, adjusted pressure, P, is proposed. P is obtained from solution of a Poisson equation over a continental region, using the simplest boundary condition along the perimeter or coastline where P equals the sea level pressure. The use of P would avoid the empiricisms and disadvantages of pressure reduction to sea level, and would produce surface pressure charts which depict the true geostrophic wind at the surface.

  19. Coastal Impact Underestimated From Rapid Sea Level Rise

    NASA Astrophysics Data System (ADS)

    Anderson, John; Milliken, Kristy; Wallace, Davin; Rodriguez, Antonio; Simms, Alexander

    2010-06-01

    A primary effect of global warming is accelerated sea level rise, which will eventually drown low-lying coastal areas, including some of the world's most populated cities. Predictions from the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) suggest that sea level may rise by as much as 0.6 meter by 2100 [Solomon et al., 2007]. However, uncertainty remains about how projected melting of the Greenland and Antarctic ice sheets will contribute to sea level rise. Further, considerable variability is introduced to these calculations due to coastal subsidence, especially along the northern Gulf of Mexico (see http://tidesandcurrents.noaa.gov/sltrends/sltrends.shtml).

  20. Explaining trends and variability in coastal relative sea level

    NASA Astrophysics Data System (ADS)

    Frederikse, Thomas; Riva, Riccardo

    2016-04-01

    Comprehensive understanding of trends and variability in coastal mean sea level is vital for protecting shores under a changing climate. To understand the behavior of coastal relative sea level (RSL), it is crucial to identify all relevant processes. We combine data from various geophysical models and observations to determine whether the trends and decadal variability observed in relative sea level at tide gauges can be explained by the sum of all known contributors. A key contributor to RSL is vertical land motion, which is caused by glacial isostatic adjustment (GIA), solid earth response to surface loading, tectonics, and local effects. We explicitly model low-frequency loading effects to correct GPS records, which leads to a more consistent trend than only using GIA models. Secondly, we create sea level fingerprints based on estimates of ice melt and changes in land hydrology, which provide the RSL contribution due to large-scale mass transport. Since coastal areas are often located on shallow continental shelves, steric effects will generally be small, and a large fraction of the decadal sea level variability will have a remote steric origin. Therefore, we determine a relation between coastal sea level and deep sea steric variability. For the period 1950-2012, we find that for many locations, including the European coast, the observed and modeled RSL time series agree well on decadal and secular scales.

  1. Sea-level variability over five glacial cycles.

    PubMed

    Grant, K M; Rohling, E J; Ramsey, C Bronk; Cheng, H; Edwards, R L; Florindo, F; Heslop, D; Marra, F; Roberts, A P; Tamisiea, M E; Williams, F

    2014-09-25

    Research on global ice-volume changes during Pleistocene glacial cycles is hindered by a lack of detailed sea-level records for time intervals older than the last interglacial. Here we present the first robustly dated, continuous and highly resolved records of Red Sea sea level and rates of sea-level change over the last 500,000 years, based on tight synchronization to an Asian monsoon record. We observe maximum 'natural' (pre-anthropogenic forcing) sea-level rise rates below 2 m per century following periods with up to twice present-day ice volumes, and substantially higher rise rates for greater ice volumes. We also find that maximum sea-level rise rates were attained within 2 kyr of the onset of deglaciations, for 85% of such events. Finally, multivariate regressions of orbital parameters, sea-level and monsoon records suggest that major meltwater pulses account for millennial-scale variability and insolation-lagged responses in Asian monsoon records.

  2. Sea water intrusion by sea-level rise: scenarios for the 21st century.

    PubMed

    Loáiciga, Hugo A; Pingel, Thomas J; Garcia, Elizabeth S

    2012-01-01

    This study presents a method to assess the contributions of 21st-century sea-level rise and groundwater extraction to sea water intrusion in coastal aquifers. Sea water intrusion is represented by the landward advance of the 10,000 mg/L iso-salinity line, a concentration of dissolved salts that renders groundwater unsuitable for human use. A mathematical formulation of the resolution of sea water intrusion among its causes was quantified via numerical simulation under scenarios of change in groundwater extraction and sea-level rise in the 21st century. The developed method is illustrated with simulations of sea water intrusion in the Seaside Area sub-basin near the City of Monterey, California (USA), where predictions of mean sea-level rise through the early 21st century range from 0.10 to 0.90 m due to increasing global mean surface temperature. The modeling simulation was carried out with a state-of-the-art numerical model that accounts for the effects of salinity on groundwater density and can approximate hydrostratigraphic geometry closely. Simulations of sea water intrusion corresponding to various combinations of groundwater extraction and sea-level rise established that groundwater extraction is the predominant driver of sea water intrusion in the study aquifer. The method presented in this work is applicable to coastal aquifers under a variety of other scenarios of change not considered in this work. For example, one could resolve what changes in groundwater extraction and/or sea level would cause specified levels of groundwater salinization at strategic locations and times.

  3. Paleoshoreline record of relative Holocene sea levels on Pacific islands

    NASA Astrophysics Data System (ADS)

    Dickinson, William R.

    2001-11-01

    Understanding the history of relative Holocene sea levels on Pacific islands is important for constraining fundamental geodynamic theories, interpreting the environments of early human occupation sites, and forecasting future environmental conditions on the islands. An observational paleoshoreline record is provided by emergent paleoshoreline indicators formed at higher relative sea levels, hence standing at higher elevations than modern counterparts. Emergent paleoshoreline notches in limestone seacliffs record paleo-high-tide levels and emergent paleoreef flats record paleo-low-tide levels, whereas emergent paleobeachrock locally records paleo-intertidal levels. Both paleonotches and paleoreefs occur along the coasts of high-standing islands exposing volcanic bedrock and uplifted reef complexes, but low-lying coralline atolls lack sufficient relief to preserve paleonotches. Controls on relative Holocene sea level include global eustatic and regional hydro-isostatic changes in ambient sea level relative to island landmasses, and shifts in the elevations of islands relative to sea level caused by thermal subsidence of the oceanic lithosphere or thermally rejuvenated loci of hotspot volcanism, by flexure of the lithosphere under the load of growing volcanic edifices (Hawaii, Samoa, Society Islands), by arching of the lithosphere over trench forebulges (Loyalty Islands, Niue, Bellona-Rennell), and by tectonism within forearc belts between active volcanic chains and trenches (Mariana Islands, Tonga, Vanuatu). The dominant pattern of relative sea-level change, where not overprinted by local tectonism or lithospheric flexure, was a uniform early Holocene rise in eustatic sea level followed by a regionally variable late Holocene hydro-isostatic drawdown in sea level. The resultant was a mid-Holocene highstand in relative sea level that affected the development of shoreline morphology throughout the tropical Pacific Ocean. The earliest human migrations into intra

  4. Helium II level measurement techniques

    NASA Astrophysics Data System (ADS)

    Celik, D.; Hilton, D. K.; Zhang, T.; Van Sciver, S. W.

    2001-05-01

    In this paper, a survey of cryogenic liquid level measurement techniques applicable to superfluid helium (He II) is given. The survey includes both continuous and discrete measurement techniques. A number of different probes and controlling circuits for this purpose have been described in the literature. They fall into one of the following categories: capacitive liquid level gauges, superconducting wire liquid level gauges, thermodynamic (heat transfer-based) liquid level gauges, resistive gauges, ultrasound and transmission line-based level detectors. The present paper reviews these techniques and their suitability for He II service. In addition to these methods, techniques for measuring the total liquid volume and mass gauging are also discussed.

  5. Observing Sea Level Change and its Causes with Satellite Remote Sensing

    NASA Astrophysics Data System (ADS)

    Boening, Carmen; Fu, Lee-Lueng; Landerer, Felix; Willis, Josh

    2016-07-01

    Sea level rise as a response to a changing climate is an imminent threat for coastal communities in the near future. Coastal zone management relies on most accurate predictions of sea level change over the coming decades for planning potential mitigation efforts. Hence, it is of high importance to accurately measure changes and understand physical processes behind them in great detail on a variety of time scales. Satellite observations of sea level height from altimetry have provided an unprecedented understanding of global changes and regional patterns for over two decades. With more and more missions providing now also observations of causes such as water mass changes due to ice melt and land hydrology as well as the ocean heat and salinity budget and local and regional wind patterns, we can now get a comprehensive understanding of the physical processes causing the short to long term changes in sea level. Here, we present an overview of sea level observations in combination with a suite of measurements looking at sea level contributions to provide insight into current and future challenges to understand the sea level budget and its impact on the accuracy of future projections.

  6. Uncertainties in Steric Sea Level Change Estimation During the Satellite Altimeter Era: Concepts and Practices

    NASA Astrophysics Data System (ADS)

    MacIntosh, C. R.; Merchant, C. J.; von Schuckmann, K.

    2017-01-01

    This article presents a review of current practice in estimating steric sea level change, focussed on the treatment of uncertainty. Steric sea level change is the contribution to the change in sea level arising from the dependence of density on temperature and salinity. It is a significant component of sea level rise and a reflection of changing ocean heat content. However, tracking these steric changes still remains a significant challenge for the scientific community. We review the importance of understanding the uncertainty in estimates of steric sea level change. Relevant concepts of uncertainty are discussed and illustrated with the example of observational uncertainty propagation from a single profile of temperature and salinity measurements to steric height. We summarise and discuss the recent literature on methodologies and techniques used to estimate steric sea level in the context of the treatment of uncertainty. Our conclusions are that progress in quantifying steric sea level uncertainty will benefit from: greater clarity and transparency in published discussions of uncertainty, including exploitation of international standards for quantifying and expressing uncertainty in measurement; and the development of community "recipes" for quantifying the error covariances in observations and from sparse sampling and for estimating and propagating uncertainty across spatio-temporal scales.

  7. Uncertainties in Steric Sea Level Change Estimation During the Satellite Altimeter Era: Concepts and Practices

    NASA Astrophysics Data System (ADS)

    MacIntosh, C. R.; Merchant, C. J.; von Schuckmann, K.

    2016-10-01

    This article presents a review of current practice in estimating steric sea level change, focussed on the treatment of uncertainty. Steric sea level change is the contribution to the change in sea level arising from the dependence of density on temperature and salinity. It is a significant component of sea level rise and a reflection of changing ocean heat content. However, tracking these steric changes still remains a significant challenge for the scientific community. We review the importance of understanding the uncertainty in estimates of steric sea level change. Relevant concepts of uncertainty are discussed and illustrated with the example of observational uncertainty propagation from a single profile of temperature and salinity measurements to steric height. We summarise and discuss the recent literature on methodologies and techniques used to estimate steric sea level in the context of the treatment of uncertainty. Our conclusions are that progress in quantifying steric sea level uncertainty will benefit from: greater clarity and transparency in published discussions of uncertainty, including exploitation of international standards for quantifying and expressing uncertainty in measurement; and the development of community "recipes" for quantifying the error covariances in observations and from sparse sampling and for estimating and propagating uncertainty across spatio-temporal scales.

  8. 50 CFR 665.812 - Sea turtle take mitigation measures.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Sea turtle take mitigation measures. 665... Pacific Pelagic Fisheries § 665.812 Sea turtle take mitigation measures. (a) Possession and use of... sea turtle handling requirements set forth in paragraph (b) of this section. (1) Hawaii...

  9. 50 CFR 665.812 - Sea turtle take mitigation measures.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Sea turtle take mitigation measures. 665... Pacific Pelagic Fisheries § 665.812 Sea turtle take mitigation measures. (a) Possession and use of... sea turtle handling requirements set forth in paragraph (b) of this section. (1) Hawaii...

  10. 50 CFR 665.812 - Sea turtle take mitigation measures.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Sea turtle take mitigation measures. 665... Pacific Pelagic Fisheries § 665.812 Sea turtle take mitigation measures. (a) Possession and use of... sea turtle handling requirements set forth in paragraph (b) of this section. (1) Hawaii...

  11. 50 CFR 665.812 - Sea turtle take mitigation measures.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Sea turtle take mitigation measures. 665... Pacific Pelagic Fisheries § 665.812 Sea turtle take mitigation measures. (a) Possession and use of... sea turtle handling requirements set forth in paragraph (b) of this section. (1) Hawaii...

  12. 50 CFR 665.812 - Sea turtle take mitigation measures.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Sea turtle take mitigation measures. 665... Pacific Pelagic Fisheries § 665.812 Sea turtle take mitigation measures. (a) Possession and use of... sea turtle handling requirements set forth in paragraph (b) of this section. (1) Hawaii...

  13. The multimillennial sea-level commitment of global warming.

    PubMed

    Levermann, Anders; Clark, Peter U; Marzeion, Ben; Milne, Glenn A; Pollard, David; Radic, Valentina; Robinson, Alexander

    2013-08-20

    Global mean sea level has been steadily rising over the last century, is projected to increase by the end of this century, and will continue to rise beyond the year 2100 unless the current global mean temperature trend is reversed. Inertia in the climate and global carbon system, however, causes the global mean temperature to decline slowly even after greenhouse gas emissions have ceased, raising the question of how much sea-level commitment is expected for different levels of global mean temperature increase above preindustrial levels. Although sea-level rise over the last century has been dominated by ocean warming and loss of glaciers, the sensitivity suggested from records of past sea levels indicates important contributions should also be expected from the Greenland and Antarctic Ice Sheets. Uncertainties in the paleo-reconstructions, however, necessitate additional strategies to better constrain the sea-level commitment. Here we combine paleo-evidence with simulations from physical models to estimate the future sea-level commitment on a multimillennial time scale and compute associated regional sea-level patterns. Oceanic thermal expansion and the Antarctic Ice Sheet contribute quasi-linearly, with 0.4 m °C(-1) and 1.2 m °C(-1) of warming, respectively. The saturation of the contribution from glaciers is overcompensated by the nonlinear response of the Greenland Ice Sheet. As a consequence we are committed to a sea-level rise of approximately 2.3 m °C(-1) within the next 2,000 y. Considering the lifetime of anthropogenic greenhouse gases, this imposes the need for fundamental adaptation strategies on multicentennial time scales.

  14. Regional Sea Level Variation: California Coastal Subsidence (Invited)

    NASA Astrophysics Data System (ADS)

    Blewitt, G.; Hammond, W. C.; Nerem, R.

    2013-12-01

    Satellite altimetry over the last two decades has measured variations in geocentric sea level (GSL), relative to the Earth system center of mass, providing valuable data to test models of physical oceanography and the effects of global climate change. The societal impacts of sea level change however relate to variations in local sea level (LSL), relative to the land at the coast. Therefore, assessing the impacts of sea level change requires coastal measurements of vertical land motion (VLM). Indeed, ΔLSL = ΔGSL - ΔVLM, with subsidence mapping 1:1 into LSL. Measurements of secular coastal VLM also allow tide-gauge data to test models of GSL over the last century in some locations, which cannot be provided by satellite data. Here we use GPS geodetic data within 15 km of the US west coast to infer regional, secular VLM. A total of 89 GPS stations met the criteria that time series span >4.5 yr, and do not have obvious non-linear variation, as may be caused by local instability. VLM rates for the GPS stations are derived in the secular reference frame ITRF2008, which aligns with the Earth system center of mass to ×0.5 mm/yr. We find that regional VLM has different behavior north and south of the Mendocino Triple Junction (MTJ). The California coast has a coherent regional pattern of subsidence averaging 0.5 mm/yr, with an increasing trend to the north. This trend generally matches GIA model predictions. Around San Francisco Bay, the observed coastal subsidence of 1.0 mm/yr coherently decreases moving away from the Pacific Ocean to very small subsidence on the east shores of the bay. This gradient is likely caused by San Andreas-Hayward Fault tectonics, and possibly by differential surface loading across the bay and Sacramento-San Joachim River Delta. Thus in addition to the trend in subsidence from GIA going northward along the California coast, tectonics may also play a role where the plate boundary fault system approaches the coast. In contrast, we find that VLM

  15. Satellite Remote Sensing: Passive-Microwave Measurements of Sea Ice

    NASA Technical Reports Server (NTRS)

    Parkinson, Claire L.; Zukor, Dorothy J. (Technical Monitor)

    2001-01-01

    Satellite passive-microwave measurements of sea ice have provided global or near-global sea ice data for most of the period since the launch of the Nimbus 5 satellite in December 1972, and have done so with horizontal resolutions on the order of 25-50 km and a frequency of every few days. These data have been used to calculate sea ice concentrations (percent areal coverages), sea ice extents, the length of the sea ice season, sea ice temperatures, and sea ice velocities, and to determine the timing of the seasonal onset of melt as well as aspects of the ice-type composition of the sea ice cover. In each case, the calculations are based on the microwave emission characteristics of sea ice and the important contrasts between the microwave emissions of sea ice and those of the surrounding liquid-water medium.

  16. Fractal geometry methods and neurocomputing for Caspian sea level forecasting

    NASA Astrophysics Data System (ADS)

    Karimova, L.; Mukhamejanova, S.; Makarenko, N.

    2003-04-01

    In this paper a method of natural dynamical systems forecasting is proposed. This method is a result of combination of topological dynamics and deterministic chaos theories. The technique enables reconstructing a universal model of the process in question from the given data directly, which is implemented by embedding the investigated time series into Euclidean space of the proper dimension. Such a model can preserve characteristics of the attractor of a dynamical system, which is supposed to generate the time series and allows constructing a correct scheme of local multidimensional prediction. The predictor is described by a continuous nonlinear function with number of its arguments depending on embedding dimension. An artificial neural network is used to approximate the function. The method is illustrated on the example of Caspian Sea level. It is the largest intercontinental reservoir without water flow, which demonstrates the unique evolution on an extent of a huge time interval, represented by the recurrent change of transgressive and regressive phases, that is noticed in illegible traces of paleodata, scanty historical information and also monitoring on short instrumental period. The instrumental time series contain not enough values to trace the global variations of the sea level. That is why we use these measurements together with historical records. The second data are preliminary processed with the fractal interpolation procedure. This is done in order to make the two series have equal time resolutions. The appropriateness of such an interpolation is verified with the help of Hurst method. We apply the delay coordinate transformation with different delay parameters instead of the canonical Takens reconstruction procedure for embedding the time series into Euclidean space. This technique is called irregular embedding and allows investigating multicyclic dynamical systems. For the problem of Caspian sea level forecasting we use a version of the irregular

  17. Hazard Risk to Near Sea-Level Populations due to Tropical Cyclone Intensification and Sea-Level Rise

    NASA Astrophysics Data System (ADS)

    Montain, J.; Byrne, J. M.; Elsner, J.

    2010-12-01

    Tropical cyclone (TC) intensification has been well documented in the science literature. TC intensification combined with sea-level rise contributes to an enhanced risk to huge populations living near sea level around the world. This study will apply spatial analysis techniques to combine the best available TC intensification data on storm surge, wave height and wind speeds; with digital elevation models and global population density estimates, to provide a first level evaluation of the increasing risk to human life and health.

  18. Shelf sea current profile measurements from the sea surface to the sea bed in autumn

    SciTech Connect

    Howarth, M.J.; Glorioso, P.D.

    1995-09-01

    Current profile measurements were obtained during the autumnal breakdown of stratification at a site in the northern North Sea where the tidal currents were weak and the water depth moderate (120 m). During the two month deployment period a succession of storms passed over the site, including one extreme event. An ADCP in a sea bed frame, a conventional current meter string and some near surface current meters were amongst the instruments deployed. The ADCP data were of high quality although the frame moved during the severest storm because of wave effects at the sea bed. Its depth coverage was from 14 to 94 m above the sea bed in 8 m cells. Comparison with the current meter string showed that the ADCP`s speeds were 20% too high (reason unknown), and that its directions were rotated by 7{degree} (perhaps due to the arrangement of the bottom frame). The value of the ADCP data at tidal, inertial and low frequencies is demonstrated and of the top cell as a reference point for the estimation of near surface shear, which was confined at most to the top 25 m. Wind-driven currents measured at 2 m depth were 0.75% of the wind speed and in a direction 25{degree} to the right of the wind.

  19. Tectonic subsidence provides insight into possible coral reef futures under rapid sea-level rise

    NASA Astrophysics Data System (ADS)

    Saunders, Megan I.; Albert, Simon; Roelfsema, Chris M.; Leon, Javier X.; Woodroffe, Colin D.; Phinn, Stuart R.; Mumby, Peter J.

    2016-03-01

    Sea-level rise will change environmental conditions on coral reef flats, which comprise extensive habitats in shallow tropical seas and support a wealth of ecosystem services. Rapid relative sea-level rise of 0.6 m over a relatively pristine coral reef in Solomon Islands, caused by a subduction earthquake in April 2007, generated a unique opportunity to examine in situ coral reef response to relative sea-level rise of the magnitude (but not the rate) anticipated by 2100. Extent of live coral was measured from satellite imagery in 2003, 2006, 2009 and 2012. Ecological data were obtained from microatolls and ecological surveys in May 2013. The reef was sampled at 12 locations where dense live hard coral remained absent, remained present or changed from absent to present following subsidence. Ecological data (substratum depth, live coral canopy depth, coral canopy height, substratum suitability, recruitment, diversity and Acropora presence) were measured at each location to identify factors associated with coral response to relative sea-level rise. Vertical and horizontal proliferation of coral occurred following subsidence. Lateral expansion of live coral, accomplished primarily by branching Acropora spp., resulted in lower diversity in regions which changed composition from pavement to dense live coral following subsidence. Of the ecological factors measured, biotic factors were more influential than abiotic factors; species identity was the most important factor in determining which regions of the reef responded to rapid sea-level rise. On relatively pristine reef flats under present climatic conditions, rapid relative sea-level rise generated an opportunity for hard coral to proliferate. However, the species assemblage of the existing reef was important in determining response to sea-level change, by providing previously bare substrate with a source of new coral colonies. Degraded reefs with altered species composition and slower coral growth rates may be less

  20. The importance of sea-level research (Plinius Medal Lecture)

    NASA Astrophysics Data System (ADS)

    Horton, Benjamin

    2016-04-01

    200 million people worldwide live in coastal regions less than 5 meters above sea level. By the end of the 21st century, this figure is estimated to increase to 500 million. These low-lying coastal regions are vulnerable to changes in sea level brought about by climate change, storms or earthquakes. But the historic and instrumental record is too short to fully understand the climate relationships and capture the occurrence of the rare, but most destructive events. The coastal sedimentary record provides a long-term and robust paleo perspective on the rates, magnitudes and spatial variability of sea-level rise and the frequency (recurrence interval) and magnitude of destructive events. Reconstructions of paleo sea level are important for identifying the meltwater contributions, constraining parameters in Earth-Ice models, and estimating past and present rates of spatially variable sea-level change associated glacial isostatic adjustment, sediment compaction and tidal range variability. Sea-level reconstructions capture multiple phases of climate and sea-level behavior for model calibration and provide a pre-anthropogenic background against which to compare recent trends. Pre-historic earthquakes (Mw>8.0) are often associated with abrupt and cyclical patterns of vertical land-motion that are manifest in coastal sedimentary archives as abrupt changes in relative sea level. Geologic evidence of paleoearthquakes elucidates characteristic and repeated pattern of land-level movements associated with the earthquake-deformation cycle. Tsunamis and storms leave behind anomalous and characteristic sediment that is incorporated into the coastal sedimentary record often as evidence of a high-energy event affecting a low-energy, depositional environment. Records of tsunamis developed from the sedimentary deposits they leave behind improve understanding of tsunami processes and frequency by expanding the age range of events available for study. Reconstructions of paleo storms

  1. The anatomy of recent large sea level fluctuations in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Landerer, Felix W.; Volkov, Denis L.

    2013-02-01

    Abstract During the boreal winter months of 2009/2010 and 2010/2011, Mediterranean mean <span class="hlt">sea</span> <span class="hlt">level</span> rose 10 cm above the average monthly climatological values. The non-seasonal anomalies were observed in <span class="hlt">sea</span> surface height (from altimetry), as well as ocean mass (from gravimetry), indicating they were mostly of barotropic nature. These relatively rapid basin-wide fluctuations occurred over time scales of 1-5 months. Here we use observations and re-analysis data to attribute the non-seasonal <span class="hlt">sea</span> <span class="hlt">level</span> and ocean mass fluctuations in the Mediterranean <span class="hlt">Sea</span> to concurrent wind stress anomalies over the adjacent subtropical Northeast Atlantic Ocean, just west of the Strait of Gibraltar, and extending into the strait itself. The observed Mediterranean <span class="hlt">sea</span> <span class="hlt">level</span> fluctuations are strongly anti-correlated with the monthly North-Atlantic-Oscillation (NAO) index.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1710077E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1710077E"><span>Characterization of extreme <span class="hlt">sea</span> <span class="hlt">level</span> at the European coast</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Elizalde, Alberto; Jorda, Gabriel; Mathis, Moritz; Mikolajewicz, Uwe</p> <p>2015-04-01</p> <p>Extreme high <span class="hlt">sea</span> <span class="hlt">levels</span> arise as a combination of storm surges and particular high tides events. Future climate simulations not only project changes in the atmospheric circulation, which induces changes in the wind conditions, but also an increase in the global mean <span class="hlt">sea</span> <span class="hlt">level</span> by thermal expansion and ice melting. Such changes increase the risk of coastal flooding, which represents a possible hazard for human activities. Therefore, it is important to investigate the pattern of <span class="hlt">sea</span> <span class="hlt">level</span> variability and long-term trends at coastal areas. In order to analyze further extreme <span class="hlt">sea</span> <span class="hlt">level</span> events at the European coast in the future climate projections, a new setup for the global ocean model MPIOM coupled with the regional atmosphere model REMO is prepared. The MPIOM irregular grid has enhanced resolution in the European region to resolve the North and the Mediterranean <span class="hlt">Seas</span> (up to 11 x 11 km at the North <span class="hlt">Sea</span>). The ocean model includes as well the full luni-solar ephemeridic tidal potential for tides simulation. To simulate the air-<span class="hlt">sea</span> interaction, the regional atmospheric model REMO is interactively coupled to the ocean model over Europe. Such region corresponds to the EuroCORDEX domain with a 50 x 50 km resolution. Besides the standard fluxes of heat, mass (freshwater), momentum and turbulent energy input, the ocean model is also forced with <span class="hlt">sea</span> <span class="hlt">level</span> pressure, in order to be able to capture the full variation of <span class="hlt">sea</span> <span class="hlt">level</span>. The hydrological budget within the study domain is closed using a hydrological discharge model. With this model, simulations for present climate and future climate scenarios are carried out to study transient changes on the <span class="hlt">sea</span> <span class="hlt">level</span> and extreme events. As a first step, two simulations (coupled and uncoupled ocean) driven by reanalysis data (ERA40) have been conducted. They are used as reference runs to evaluate the climate projection simulations. For selected locations at the coast side, time series of <span class="hlt">sea</span> <span class="hlt">level</span> are separated on its different</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NatCo...711969M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatCo...711969M"><span>A global reanalysis of storm surges and extreme <span class="hlt">sea</span> <span class="hlt">levels</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Muis, Sanne; Verlaan, Martin; Winsemius, Hessel C.; Aerts, Jeroen C. J. H.; Ward, Philip J.</p> <p>2016-06-01</p> <p>Extreme <span class="hlt">sea</span> <span class="hlt">levels</span>, caused by storm surges and high tides, can have devastating societal impacts. To effectively protect our coasts, global information on coastal flooding is needed. Here we present the first global reanalysis of storm surges and extreme <span class="hlt">sea</span> <span class="hlt">levels</span> (GTSR data set) based on hydrodynamic modelling. GTSR covers the entire world's coastline and consists of time series of tides and surges, and estimates of extreme <span class="hlt">sea</span> <span class="hlt">levels</span>. Validation shows that there is good agreement between modelled and observed <span class="hlt">sea</span> <span class="hlt">levels</span>, and that the performance of GTSR is similar to that of many regional hydrodynamic models. Due to the limited resolution of the meteorological forcing, extremes are slightly underestimated. This particularly affects tropical cyclones, which requires further research. We foresee applications in assessing flood risk and impacts of climate change. As a first application of GTSR, we estimate that 1.3% of the global population is exposed to a 1 in 100-year flood.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4931224','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4931224"><span>A global reanalysis of storm surges and extreme <span class="hlt">sea</span> <span class="hlt">levels</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Muis, Sanne; Verlaan, Martin; Winsemius, Hessel C.; Aerts, Jeroen C. J. H.; Ward, Philip J.</p> <p>2016-01-01</p> <p>Extreme <span class="hlt">sea</span> <span class="hlt">levels</span>, caused by storm surges and high tides, can have devastating societal impacts. To effectively protect our coasts, global information on coastal flooding is needed. Here we present the first global reanalysis of storm surges and extreme <span class="hlt">sea</span> <span class="hlt">levels</span> (GTSR data set) based on hydrodynamic modelling. GTSR covers the entire world's coastline and consists of time series of tides and surges, and estimates of extreme <span class="hlt">sea</span> <span class="hlt">levels</span>. Validation shows that there is good agreement between modelled and observed <span class="hlt">sea</span> <span class="hlt">levels</span>, and that the performance of GTSR is similar to that of many regional hydrodynamic models. Due to the limited resolution of the meteorological forcing, extremes are slightly underestimated. This particularly affects tropical cyclones, which requires further research. We foresee applications in assessing flood risk and impacts of climate change. As a first application of GTSR, we estimate that 1.3% of the global population is exposed to a 1 in 100-year flood. PMID:27346549</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016Natur.532...42F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016Natur.532...42F"><span>Island biogeography: Shaped by <span class="hlt">sea-level</span> shifts</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fernández-Palacios, José María</p> <p>2016-04-01</p> <p>An analysis of changes in island topography and climate that have occurred since the last glacial maximum 21,000 years ago shows how <span class="hlt">sea-level</span> change has influenced the current biodiversity of oceanic islands. See Letter p.99</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GeoRL..42.6747M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GeoRL..42.6747M"><span>Seasonal coastal <span class="hlt">sea</span> <span class="hlt">level</span> prediction using a dynamical model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McIntosh, Peter C.; Church, John A.; Miles, Elaine R.; Ridgway, Ken; Spillman, Claire M.</p> <p>2015-08-01</p> <p><span class="hlt">Sea</span> <span class="hlt">level</span> varies on a range of time scales from tidal to decadal and centennial change. To date, little attention has been focussed on the prediction of interannual <span class="hlt">sea</span> <span class="hlt">level</span> anomalies. Here we demonstrate that forecasts of coastal <span class="hlt">sea</span> <span class="hlt">level</span> anomalies from the dynamical Predictive Ocean Atmosphere Model for Australia (POAMA) have significant skill throughout the equatorial Pacific and along the eastern boundaries of the Pacific and Indian Oceans at lead times out to 8 months. POAMA forecasts for the western Pacific generally have greater skill than persistence, particularly at longer lead times. POAMA also has comparable or greater skill than previously published statistical forecasts from both a Markov model and canonical correlation analysis. Our results indicate the capability of physically based models to address the challenge of providing skillful forecasts of seasonal <span class="hlt">sea</span> <span class="hlt">level</span> fluctuations for coastal communities over a broad area and at a range of lead times.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.youtube.com/watch?v=7l7BY2B3jSU','SCIGOVIMAGE-NASA'); return false;" href="http://www.youtube.com/watch?v=7l7BY2B3jSU"><span>Twenty-two Years of <span class="hlt">Sea</span> <span class="hlt">Level</span> Rise</span></a></p> <p><a target="_blank" href="http://www.nasa.gov/multimedia/videogallery/index.html">NASA Video Gallery</a></p> <p></p> <p></p> <p>This visualization shows total <span class="hlt">sea</span> <span class="hlt">level</span> change between the beginning of 1993 and the end of 2014, based on data collected from the TOPEX/Poisedon, Jason-1, and Jason-2 satellites. Blue regions are...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6784832','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6784832"><span>Chronology of fluctuating <span class="hlt">sea</span> <span class="hlt">levels</span> since the triassic</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Haq, B.U.; Hardenbol, J.; Vail, P.R.</p> <p>1987-03-06</p> <p>Advances in sequence stratigraphy and the development of depositional models have helped explain the origin of genetically related sedimentary packages during <span class="hlt">sea</span> <span class="hlt">level</span> cycles. These concepts have provided the basis for the recognition of <span class="hlt">sea</span> <span class="hlt">level</span> events in subsurface data and in outcrops of marine sediments around the world. Knowledge of these events has led to a new generation of Mesozoic and Cenozoic global cycle charts that chronicle the history of <span class="hlt">sea</span> <span class="hlt">level</span> fluctuations during the past 250 million years in greater detail than was possible from seismic-stratigraphic data alone. An effort has been made to develop a realistic and accurate time scale and widely applicable chronostratigraphy and to integrate depositional sequences documented in public domain outcrop sections from various basins with this chronostratigraphic framework. A description of this approach and an account of the results, illustrated by <span class="hlt">sea</span> <span class="hlt">level</span> cycle charts of the Cenozoic, Cretaceous, Jurassic, and Triassic intervals, are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70121272','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70121272"><span>[Book review] <span class="hlt">Sea</span> <span class="hlt">level</span> rise: history and consequences</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Grossman, Eric E.</p> <p>2004-01-01</p> <p>Review of: <span class="hlt">Sea</span> <span class="hlt">level</span> Rise: history and consequences. Bruce Douglas, Michael S. Kearney and Stephen P. Leatherman (eds), Sand Diego: Academic Press, 2001, 232 pp. plus CD-RIM, US$64.95, hardback. ISBN 0-12-221345-9.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.G41B0939F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.G41B0939F"><span>Regional <span class="hlt">sea</span> <span class="hlt">level</span> change in the Thailand-Indonesia region</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fenoglio-Marc, L.; Becker, M. H.; Buchhaupt, C.</p> <p>2013-12-01</p> <p>It is expected that the regional <span class="hlt">sea</span> <span class="hlt">level</span> rise will strongly affect particular regions with direct impacts including submergence of coastal zones, rising water tables and salt intrusion into groundwaters. It can possibly also exacerbate other factors as floodings, associated to storms and hurricanes, as well as ground subsidence of anthropogenic nature. The Thailand-Vietnam-Indonesian region is one of those zones. On land, the Chao-Praya and Mekong Delta are fertile alluvial zones. The potential for <span class="hlt">sea</span> <span class="hlt">level</span> increases and extreme floodings due to global warming makes the Deltas a place where local, regional, and global environmental changes are converging. We investigate the relative roles of regional and global mechanisms resulting in multidecadal variations and inflections in the rate of <span class="hlt">sea</span> <span class="hlt">level</span> change. Altimetry and GRACE data are used to investigate the variation of land floodings. The land surface water extent is evaluated at 25 km sampling intervals over fifteen years (1993-2007) using a multisatellite methodology which captures the extent of episodic and seasonal inundations, wetlands, rivers, lakes, and irrigated agriculture, using passive and active (microwaves and visible observations. The regional <span class="hlt">sea</span> <span class="hlt">level</span> change is analysed during the period 1993-2012 using satellite altimetry, wind and ocean model data, tide gauge data and GPS. The rates of absolute eustatic <span class="hlt">sea</span> <span class="hlt">level</span> rise derived from satellite altimetry through 19-year long precise altimeter observations are in average higher than the global mean rate. Several tide gauge records indicate an even higher <span class="hlt">sea</span> <span class="hlt">level</span> rise relative to land. We show that the <span class="hlt">sea</span> <span class="hlt">level</span> change is closely linked to the ENSO mode of variability and strongly affected by changes in wind forcing and ocean circulation. We have determined the vertical crustal motion at a given tide gauge location by differencing the tide gauge <span class="hlt">sea</span> <span class="hlt">level</span> time-series with an equivalent time-series derived from satellite altimetry and by computing</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.C42A..04B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.C42A..04B"><span>Contribution of Iceland's Ice Caps to <span class="hlt">Sea</span> <span class="hlt">Level</span> Change</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bjornsson, H.; Gudmundsson, S.; Pálsson, F.; Magnusson, E.; Sigurdsson, O.; Johannesson, T.; Thorsteinsson, T.; Berthier, E.</p> <p>2011-12-01</p> <p>We report on the volume change of Icelandic ice caps during several time intervals from the 1980s until present. Changes in ice volume have been monitored by both annual mass balance <span class="hlt">measurements</span> on the glaciers and by comparison of multi-temporal digital surface elevation models derived from various satellite and airborne remote observations. The glaciers' mass budgets have declined significantly, from being close to zero in the 1980s and early 1990s, to becoming on average negative by -0.7 to -1.8 m w.e. per year since the mid 1990s. This reduction in mass balance is related to rapid climate warming in Iceland, approx. 1.5 °C since the early 1980s. High mass balance sensitivities of -1 to -2 m w. e. per °C are identified. The current contribution of Icelandic ice caps to <span class="hlt">sea</span> <span class="hlt">level</span> change is estimated to be ~0.03 mm SLE per year. Icelandic ice caps contain in total approx. 3,600 cubic km of ice, which if melted would raise <span class="hlt">sea</span> <span class="hlt">level</span> by approx. 1 cm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26160951','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26160951"><span><span class="hlt">SEA-LEVEL</span> RISE. <span class="hlt">Sea-level</span> rise due to polar ice-sheet mass loss during past warm periods.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dutton, A; Carlson, A E; Long, A J; Milne, G A; Clark, P U; DeConto, R; Horton, B P; Rahmstorf, S; Raymo, M E</p> <p>2015-07-10</p> <p>Interdisciplinary studies of geologic archives have ushered in a new era of deciphering magnitudes, rates, and sources of <span class="hlt">sea-level</span> rise from polar ice-sheet loss during past warm periods. Accounting for glacial isostatic processes helps to reconcile spatial variability in peak <span class="hlt">sea</span> <span class="hlt">level</span> during marine isotope stages 5e and 11, when the global mean reached 6 to 9 meters and 6 to 13 meters higher than present, respectively. Dynamic topography introduces large uncertainties on longer time scales, precluding robust <span class="hlt">sea-level</span> estimates for intervals such as the Pliocene. Present climate is warming to a <span class="hlt">level</span> associated with significant polar ice-sheet loss in the past. Here, we outline advances and challenges involved in constraining ice-sheet sensitivity to climate change with use of paleo-<span class="hlt">sea</span> <span class="hlt">level</span> records.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920037309&hterms=Sargasso+Sea&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DSargasso%2BSea','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920037309&hterms=Sargasso+Sea&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DSargasso%2BSea"><span><span class="hlt">Sea</span> <span class="hlt">level</span> differences across the Gulf Stream and Kuroshio extension</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zlotnicki, Victor</p> <p>1991-01-01</p> <p>The <span class="hlt">sea</span> <span class="hlt">level</span> differences between the Sargasso <span class="hlt">Sea</span> and the slope waters across the Gulf Stream region, averaged between 73 and 61 deg W, and the comparable areas across the Kuroshio extension region, averaged between 143 and 156 deg E, were estimated using the Geosat altimeter data obtained between November 1986 and December 1988. The <span class="hlt">sea-level</span> differences between the two regions showed a strong correlation between the northwest Atlantic and Pacific, dominated by annual cycles that peak in late-September to mid-October, with about 9 cm (the Gulf Stream region) and about 6.9 cm (Kuroshio region) amplitudes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11679657','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11679657"><span>Climate change. How fast are <span class="hlt">sea</span> <span class="hlt">levels</span> rising?</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Church, J A</p> <p>2001-10-26</p> <p><span class="hlt">Sea</span> <span class="hlt">levels</span> are rising as a result of global warming, but assessing the rate of the rise is proving difficult. In his Perspective, Church highlights the report by Cabanes et al., who have reassessed observational data and find that it is closer to model estimates than previously found. However, observational data are still limited and models disagree in their regional projections. With present data and models, regional <span class="hlt">sea-level</span> changes cannot be predicted with confidence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AIPC.1157...19P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AIPC.1157...19P"><span>Adapting to Rising <span class="hlt">Sea</span> <span class="hlt">Level</span>: A Florida Perspective</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Parkinson, Randall W.</p> <p>2009-07-01</p> <p>Global climate change and concomitant rising <span class="hlt">sea</span> <span class="hlt">level</span> will have a profound impact on Florida's coastal and marine systems. <span class="hlt">Sea-level</span> rise will increase erosion of beaches, cause saltwater intrusion into water supplies, inundate coastal marshes and other important habitats, and make coastal property more vulnerable to erosion and flooding. Yet most coastal areas are currently managed under the premise that <span class="hlt">sea-level</span> rise is not significant and the shorelines are static or can be fixed in place by engineering structures. The new reality of <span class="hlt">sea-level</span> rise and extreme weather due to climate change requires a new style of planning and management to protect resources and reduce risk to humans. Scientists must: (1) assess existing coastal vulnerability to address short term management issues and (2) model future landscape change and develop sustainable plans to address long term planning and management issues. Furthermore, this information must be effectively transferred to planners, managers, and elected officials to ensure their decisions are based upon the best available information. While there is still some uncertainty regarding the details of rising <span class="hlt">sea</span> <span class="hlt">level</span> and climate change, development decisions are being made today which commit public and private investment in real estate and associated infrastructure. With a design life of 30 yrs to 75 yrs or more, many of these investments are on a collision course with rising <span class="hlt">sea</span> <span class="hlt">level</span> and the resulting impacts will be significant. In the near term, the utilization of engineering structures may be required, but these are not sustainable and must ultimately yield to "managed withdrawal" programs if higher <span class="hlt">sea-level</span> elevations or rates of rise are forthcoming. As an initial step towards successful adaptation, coastal management and planning documents (i.e., comprehensive plans) must be revised to include reference to climate change and rising <span class="hlt">sea-level</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11.8231G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11.8231G"><span>Steric and Mass-Induced <span class="hlt">Sea</span> <span class="hlt">Level</span> Variations in the Mediterranean <span class="hlt">Sea</span>, Revisited</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Garcia-Garcia, D.; Chao, B. F.; Boy, J.-P.</p> <p>2009-04-01</p> <p>Observed by radar altimetry satellites such as TOPEX/Poseidon (T/P) and Jason-1/2, the total <span class="hlt">Sea</span> <span class="hlt">Level</span> Variations (SLV) are produced by a combination of the steric and mass-induced components. The steric SLV can be computed from in situ <span class="hlt">measurements</span> of temperature and salinity profiles, or from Ocean General Circulation Models (OGCM) that can assimilate those <span class="hlt">measurements</span>. Mass-induced SLV can be estimated, since 2002, from Time-Variable Gravity (TVG) <span class="hlt">measurements</span> by the GRACE satellite mission. This methodology has been successfully applied in estimation of the global ocean mass-induced SLV. However, some difficulties arise when studying semi-enclosed basins due to land aliasing of the GRACE TVG signal. The problem is specially complicated in the Mediterranean <span class="hlt">Sea</span> as reported in previous studies. We revisit this problem analyzing release 4 of the GRACE data set, which represents a time series 3 times longer than in previous studies, by means of new and more efficient filters to reduce the noise in the high degree and order spherical harmonics coefficients. The seasonal and non-seasonal signals are analyzed. From the comparison of GRACE with altimetry data a general underestimation of the steric term is observed in the OGCMs used.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21452969','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21452969"><span>Adrenocortical suppression in highland chick embryos is restored during incubation at <span class="hlt">sea</span> <span class="hlt">level</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Salinas, Carlos E; Villena, Mercedes; Blanco, Carlos E; Giussani, Dino A</p> <p>2011-01-01</p> <p>By combining the chick embryo model with incubation at high altitude, this study tested the hypothesis that development at high altitude is related to a fetal origin of adrenocortical but not adrenomedullary suppression and that hypoxia is the mechanism underlying the relationship. Fertilized eggs from <span class="hlt">sea-level</span> or high altitude hens were incubated at <span class="hlt">sea</span> <span class="hlt">level</span> or high altitude. Fertilized eggs from <span class="hlt">sea-level</span> hens were also incubated at altitude with oxygen supplementation. At day 20 of incubation, embryonic blood was taken for <span class="hlt">measurement</span> of plasma corticotropin, corticosterone, and Po(2). Following biometry, the adrenal glands were collected and frozen for <span class="hlt">measurement</span> of catecholamine content. Development of chick embryos at high altitude led to pronounced adrenocortical blunting, but an increase in adrenal catecholamine content. These effects were similar whether the fertilized eggs were laid by <span class="hlt">sea-level</span> or high altitude hens. The effects of high altitude on the stress axes were completely prevented by incubation at high altitude with oxygen supplementation. When chick embryos from high altitude hens were incubated at <span class="hlt">sea</span> <span class="hlt">level</span>, plasma hormones and adrenal catecholamine content were partially restored toward <span class="hlt">levels</span> <span class="hlt">measured</span> in <span class="hlt">sea-level</span> chick embryos. There was a significant correlation between adrenocortical blunting and elevated adrenal catecholamine content with both asymmetric growth restriction and fetal hypoxia. The data support the hypothesis tested and provide evidence to isolate the direct contribution of developmental hypoxia to alterations in the stress system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010OcSci...6..311I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010OcSci...6..311I"><span>Seasonal variability of the Caspian <span class="hlt">Sea</span> three-dimensional circulation, <span class="hlt">sea</span> <span class="hlt">level</span> and air-<span class="hlt">sea</span> interaction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ibrayev, R. A.; Özsoy, E.; Schrum, C.; Sur, H. I.</p> <p>2010-03-01</p> <p>A three-dimensional primitive equation model including <span class="hlt">sea</span> ice thermodynamics and air-<span class="hlt">sea</span> interaction is used to study seasonal circulation and water mass variability in the Caspian <span class="hlt">Sea</span> under the influence of realistic mass, momentum and heat fluxes. River discharges, precipitation, radiation and wind stress are seasonally specified in the model, based on available data sets. The evaporation rate, sensible and latent heat fluxes at the <span class="hlt">sea</span> surface are computed interactively through an atmospheric boundary layer sub-model, using the ECMWF-ERA15 re-analysis atmospheric data and model generated <span class="hlt">sea</span> surface temperature. The model successfully simulates <span class="hlt">sea-level</span> changes and baroclinic circulation/mixing features with forcing specified for a selected year. The results suggest that the seasonal cycle of wind stress is crucial in producing basin circulation. Seasonal cycle of <span class="hlt">sea</span> surface currents presents three types: cyclonic gyres in December-January; Eckman south-, south-westward drift in February-July embedded by western and eastern southward coastal currents and transition type in August-November. Western and eastern northward sub-surface coastal currents being a result of coastal local dynamics at the same time play an important role in meridional redistribution of water masses. An important part of the work is the simulation of <span class="hlt">sea</span> surface topography, yielding verifiable results in terms of <span class="hlt">sea</span> <span class="hlt">level</span>. The model successfully reproduces <span class="hlt">sea</span> <span class="hlt">level</span> variability for four coastal points, where the observed data are available. Analyses of heat and water budgets confirm climatologic estimates of heat and moisture fluxes at the <span class="hlt">sea</span> surface. Experiments performed with variations in external forcing suggest a sensitive response of the circulation and the water budget to atmospheric and river forcing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009OcScD...6.1913I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009OcScD...6.1913I"><span>Seasonal variability of the Caspian <span class="hlt">Sea</span> three-dimensional circulation, <span class="hlt">sea</span> <span class="hlt">level</span> and air-<span class="hlt">sea</span> interaction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ibrayev, R. A.; Özsoy, E.; Schrum, C.; Sur, H. İ.</p> <p>2009-09-01</p> <p>A three-dimensional primitive equation model including <span class="hlt">sea</span> ice thermodynamics and air-<span class="hlt">sea</span> interaction is used to study seasonal circulation and water mass variability in the Caspian <span class="hlt">Sea</span> under the influence of realistic mass, momentum and heat fluxes. River discharges, precipitation, radiation and wind stress are seasonally specified in the model, based on available data sets. The evaporation rate, sensible and latent heat fluxes at the <span class="hlt">sea</span> surface are computed interactively through an atmospheric boundary layer sub-model, using the ECMWF-ERA15 re-analysis atmospheric data and model generated <span class="hlt">sea</span> surface temperature. The model successfully simulates <span class="hlt">sea-level</span> changes and baroclinic circulation/mixing features with forcing specified for a selected year. The results suggest that the seasonal cycle of wind stress is crucial in producing basin circulation. Seasonal cycle of <span class="hlt">sea</span> surface currents presents three types: cyclonic gyres in December-January; Eckman south-, south-westward drift in February-July embedded by western and eastern southward coastal currents and transition type in August-November. Western and eastern northward sub-surface coastal currents being a result of coastal local dynamics at the same time play an important role in meridional redistribution of water masses. An important part of the work is the simulation of <span class="hlt">sea</span> surface topography, yielding verifiable results in terms of <span class="hlt">sea</span> <span class="hlt">level</span>. Model successfully reproduces <span class="hlt">sea</span> <span class="hlt">level</span> variability for four coastal points, where the observed data are available. Analyses of heat and water budgets confirm climatologic estimates of heat and moisture fluxes at the <span class="hlt">sea</span> surface. Experiments performed with variations in external forcing suggest a sensitive response of the circulation and the water budget to atmospheric and river forcing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.V53A3127H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.V53A3127H"><span><span class="hlt">Sea</span> <span class="hlt">level</span> Variability and Juan de Fuca Bathymetry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huybers, P. J.; Boulahanis, B.; Proistosescu, C.; Langmuir, C. H.; Carbotte, S. M.; Katz, R. F.</p> <p>2015-12-01</p> <p>That deglaciation influences mid-ocean ridge volcanism is well established for Iceland, where depressurization associated with melting a ~2 km ice cap led to order of magnitude increases in volcanism during the last deglaciation. The case was also made that the more subtle ~100 m changes in <span class="hlt">sea</span> <span class="hlt">level</span> that accompany glacial cycles have identifiable implications for undersea mid-ocean ridge systems using both models and data from the Australian-Antarctic Ridge (Crowley et al., 2015). <span class="hlt">Sea</span> <span class="hlt">level</span> rising at ~1 cm/year during deglaciation leads to an expectation of ~10% decreases in melt production at ridges, given mantle upwelling rates of ˜3 cm/yr at intermediate spreading ridges and mantle density being ~3 times that of seawater. The implications of variations in melt production for bathymetry, however, involve numerous considerations, including whether melt signals are cancelled within the melt column, appreciably alter accretionary or fault processes, and have identifiable surface expressions. Further empirical assessment of bathymetry is thus useful for purposes of confirming patterns and constraining processes. Here we report on spectral analyses of bathymetry recently acquired from the Juan de Fuca ridge between 44°30'N and 45°15'N during the <span class="hlt">Sea</span>VOICE expedition. Multibeam swath sonar data were acquired with an EM122 sonar insonfiying seafloor to crustal ages of ˜2 ma with 35 m spatial resolution. We examine (1.) the statistical significance of concentrations of bathymetric variability at the 100 ky, 41 ky, and 23 ky periods characteristic of late-Pleistocene <span class="hlt">sea</span> <span class="hlt">level</span> variability; (2.) whether <span class="hlt">sea</span> <span class="hlt">level</span> responses are primarily at 41 ky periods in crust accreted during the early Pleistocene, when global <span class="hlt">sea</span> <span class="hlt">level</span> variations were primarily at this period; and (3.) if <span class="hlt">sea</span> <span class="hlt">level</span> responses are superimposed on bathymetry variations or, instead, align with fault features. We also note that Juan de Fuca's proximity to the Cordilleran Ice Sheet implies that regional</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20120010653&hterms=sea+level&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dsea%2Blevel','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20120010653&hterms=sea+level&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dsea%2Blevel"><span>Terrestrial Waters and <span class="hlt">Sea</span> <span class="hlt">Level</span> Variations on Interannual Time Scale</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Llovel, W.; Becker, M.; Cazenave, A.; Jevrejeva, S.; Alkama, R.; Decharme, B.; Douville, H.; Ablain, M.; Beckley, B.</p> <p>2011-01-01</p> <p>On decadal to multi-decadal time scales, thermal expansion of <span class="hlt">sea</span> waters and land ice loss are the main contributors to <span class="hlt">sea</span> <span class="hlt">level</span> variations. However, modification of the terrestrial water cycle due to climate variability and direct anthropogenic forcing may also affect <span class="hlt">sea</span> <span class="hlt">level</span>. For the past decades, variations in land water storage and corresponding effects on <span class="hlt">sea</span> <span class="hlt">level</span> cannot be directly estimated from observations because these are almost non-existent at global continental scale. However, global hydrological models developed for atmospheric and climatic studies can be used for estimating total water storage. For the recent years (since mid-2002), terrestrial water storage change can be directly estimated from observations of the GRACE space gravimetry mission. In this study, we analyse the interannual variability of total land water storage, and investigate its contribution to mean <span class="hlt">sea</span> <span class="hlt">level</span> variability at interannual time scale. We consider three different periods that, each, depend on data availability: (1) GRACE era (2003-2009), (2) 1993-2003 and (3) 1955-1995. For the GRACE era (period 1), change in land water storage is estimated using different GRACE products over the 33 largest river basins worldwide. For periods 2 and 3, we use outputs from the ISBA-TRIP (Interactions between Soil, Biosphere, and Atmosphere-Total Runoff Integrating Pathways) global hydrological model. For each time span, we compare change in land water storage (expressed in <span class="hlt">sea</span> <span class="hlt">level</span> equivalent) to observed mean <span class="hlt">sea</span> <span class="hlt">level</span>, either from satellite altimetry (periods 1 and 2) or tide gauge records (period 3). For each data set and each time span, a trend has been removed as we focus on the interannual variability. We show that whatever the period considered, interannual variability of the mean <span class="hlt">sea</span> <span class="hlt">level</span> is essentially explained by interannual fluctuations in land water storage, with the largest contributions arising from tropical river basins.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20010067769','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20010067769"><span><span class="hlt">Sea</span>WIFS Postlaunch Technical Report Series. Volume 13; The <span class="hlt">Sea</span>WiFS Photometer Revision for Incident Surface <span class="hlt">Measurement</span> (<span class="hlt">Sea</span>PRISM) Field Commissioning</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hooker, Stanford B. (Editor); Zibordi, Giuseppe; Berthon, Jean-Francois; Bailey, Sean W.; Pietras, Christophe M.; Firestone, Elaine R. (Editor)</p> <p>2000-01-01</p> <p>This report documents the scientific activities that took place at the Acqua Alta Oceanographic Tower (AAOT) in the northern Adriatic <span class="hlt">Sea</span> off the coast of Italy from 2-6 August 1999. The ultimate objective of the field campaign was to evaluate the capabilities of a new instrument called the <span class="hlt">Sea</span>WiFS Photometer Revision for Incident Surface <span class="hlt">Measurements</span> (<span class="hlt">Sea</span>PRISM). <span class="hlt">Sea</span>PRISM is based on a CE-318 sun photometer made by CIMEL Electronique (Paris, France). The CE-318 is an automated, robotic system which <span class="hlt">measures</span> the direct sun irradiance plus the sky radiance in the sun plane and in the almucantar plane. The data are transmitted over a satellite link, and this remote operation capability has made the device very useful for atmospheric <span class="hlt">measurements</span>. The revision to the CE-318 that makes the instrument potentially useful for <span class="hlt">Sea</span>WiFS calibration and validation activities is to include a capability for <span class="hlt">measuring</span> the radiance leaving the <span class="hlt">sea</span> surface in wavelengths suitable for the determination of chlorophyll a concentration. The initial evaluation of this new capability involved above- and in-water <span class="hlt">measurement</span> protocols. An intercomparison of the water-leaving radiances derived from <span class="hlt">Sea</span>PRISM and an in-water system showed the overall spectral agreement was approximately 8.6%, but the blue-green channels intercompared at the 5% <span class="hlt">level</span>. A blue-green band ratio comparison was at the 4% <span class="hlt">level</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE10006E..0GM','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE10006E..0GM"><span>Dynamic analysis of <span class="hlt">sea</span> wave data <span class="hlt">measured</span> by LED lidar</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mori, Yasukuni; Shimada, Shohei; Shiina, Tatsuo; Baji, Hiroyuki; Takemoto, Sae</p> <p>2016-10-01</p> <p>Form of <span class="hlt">sea</span> wave is greatly affected by not just flow and depth of <span class="hlt">sea</span> water, but also wind blowing on the <span class="hlt">sea</span> surface. Therefore, <span class="hlt">measurement</span> and analysis of <span class="hlt">sea</span> wave motion is of assistance for control and operational safety of boats and ships. Generally, oceanic information is gauged by acoustic and electric wave. But these methods have not provided enough spatial and temporal resolution, and are completely out of touch with the on-site needs. Thus, the LED liar for <span class="hlt">sea</span> wave <span class="hlt">measurement</span> has been developed. The dynamic analysis of <span class="hlt">sea</span> wave image <span class="hlt">measured</span> by the LED lidar was conducted and the relationship with wind speed was evaluated. In this report, we first present the specifications and <span class="hlt">measurement</span> methodologies of the LED lidar. Then we describe the actual <span class="hlt">measurements</span> of <span class="hlt">sea</span> wave with shallow angle by using this lidar and the results of their analysis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002AGUFMOS71D0325D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002AGUFMOS71D0325D"><span>Extending the Instrumental Record of <span class="hlt">Sea-Level</span> Change: A 1300-Year <span class="hlt">Sea-Level</span> Record From Eastern Connecticut</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Donnelly, J. P.; Cleary, P.</p> <p>2002-12-01</p> <p>The instrumental record of <span class="hlt">sea-level</span> change in the northeastern United States extends back to the early 20th century and at New York City (NYC) extends back to 1856. These tide gauge records indicate that <span class="hlt">sea</span> <span class="hlt">level</span> has risen at a rate of 2.5 to 4 mm/year over the last 100-150 years. Geologic evidence of <span class="hlt">sea-level</span> change in the region over the last 2,000 years indicates rates of <span class="hlt">sea-level</span> rise of about 1 mm/year or less. The discordance between the instrumental and geologic records is frequently cited as potentially providing evidence that anthropogenic warming of the climate system has resulted in an increase in the rate of <span class="hlt">sea-level</span> rise. In order to begin to test the hypothesis that acceleration in the rate of <span class="hlt">sea-level</span> rise has occurred in the last 150 years due to anthropogenic climate warming, accurate and precise information on the timing of the apparent acceleration in <span class="hlt">sea-level</span> rise are needed. Here we construct a high-resolution relative <span class="hlt">sea-level</span> record for the past 1350 years by dating basal salt marsh peat samples above a glacial erratic in a western Connecticut salt marsh. Preservation of marsh vegetation remains in the sediment record that has a narrow vertical habitat range at the upper end of the tidal range provides information on past <span class="hlt">sea</span> <span class="hlt">levels</span>. { \\it Spartina patens} (marsh hay) and { \\it Juncus gerardi} (black rush) dominate both the modern marsh and their remains are the major constituent of the marsh sediments and occur in the modern marsh between mean high water (MHW) and mean highest high water. We use the elevation distribution of modern plant communities to estimate the relationship of sediment samples to paleo-mean high water. The chronology is based on 15 radiocarbon ages, supplemented by age estimates derived from the horizons of industrial Pb pollution and pollen indicative of European land clearance. Thirteen of the radiocarbon ages and the Pb and pollen data come from samples taken along a contact between marsh peat and a glacial</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AdAtS..34..383W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AdAtS..34..383W"><span>Statistical modeling and trend detection of extreme <span class="hlt">sea</span> <span class="hlt">level</span> records in the Pearl River Estuary</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Weiwen; Zhou, Wen</p> <p>2017-03-01</p> <p><span class="hlt">Sea</span> <span class="hlt">level</span> rise has become an important issue in global climate change studies. This study investigates trends in <span class="hlt">sea</span> <span class="hlt">level</span> records, particularly extreme records, in the Pearl River Estuary, using <span class="hlt">measurements</span> from two tide gauge stations in Macau and Hong Kong. Extremes in the original <span class="hlt">sea</span> <span class="hlt">level</span> records (daily higher high water heights) and in tidal residuals with and without the 18.6-year nodal modulation are investigated separately. Thresholds for defining extreme <span class="hlt">sea</span> <span class="hlt">levels</span> are calibrated based on extreme value theory. Extreme events are then modeled by peaks-over-threshold models. The model applied to extremes in original <span class="hlt">sea</span> <span class="hlt">level</span> records does not include modeling of their durations, while a geometric distribution is added to model the duration of extremes in tidal residuals. Realistic modeling results are recommended in all stationary models. Parametric trends of extreme <span class="hlt">sea</span> <span class="hlt">level</span> records are then introduced to nonstationary models through a generalized linear model framework. The result shows that, in recent decades, since the 1960s, no significant trends can be found in any type of extreme at any station, which may be related to a reduction in the influence of tropical cyclones in the region. For the longer-term record since the 1920s at Macau, a regime shift of tidal amplitudes around the 1970s may partially explain the diverse trend of extremes in original <span class="hlt">sea</span> <span class="hlt">level</span> records and tidal residuals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2003/of03-108/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2003/of03-108/"><span>Coastal vulnerability assessment of Gulf Islands National Seashore (GUIS) to <span class="hlt">sea-level</span> rise</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Pendleton, Elizabeth A.; Hammar-Klose, Erika S.; Thieler, E. Robert; Williams, S. Jeffress</p> <p>2004-01-01</p> <p>A coastal vulnerability index (CVI) was used to map the relative vulnerability of the coast to future <span class="hlt">sea-level</span> rise within Gulf Islands National Seashore (GUIS) in Mississippi and Florida. The CVI ranks the following in terms of their physical contribution to <span class="hlt">sea-level</span> rise-related coastal change: geomorphology, regional coastal slope, rate of relative <span class="hlt">sea-level</span> rise, shoreline change rates, mean tidal range and mean wave height. The rankings for each variable were combined and an index value calculated for 1-minute grid cells covering the park. The CVI highlights those regions where the physical effects of <span class="hlt">sea-level</span> rise might be the greatest. This approach combines the coastal system's susceptibility to change with its natural ability to adapt to changing environmental conditions, yielding a quantitative, although relative, <span class="hlt">measure</span> of the park's natural vulnerability to the effects of <span class="hlt">sea-level</span> rise. The Gulf Islands in Mississippi and Florida consist of stable and washover dominated portions of barrier beach backed by wetland and marsh. The areas likely to be most vulnerable to <span class="hlt">sea-level</span> rise are those with the highest occurrence of overwash, the highest rates of shoreline change, the gentlest regional coastal slope, and the highest rates of relative <span class="hlt">sea-level</span> rise. The CVI provides an objective technique for evaluation and long-term planning by scientists and park managers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920048967&hterms=Barometers&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DBarometers','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920048967&hterms=Barometers&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DBarometers"><span>Orthogonal stack of global tide gauge <span class="hlt">sea</span> <span class="hlt">level</span> data</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Trupin, A.; Wahr, J.</p> <p>1990-01-01</p> <p>Yearly and monthly tide gauge <span class="hlt">sea</span> <span class="hlt">level</span> data from around the globe are fitted to numerically generated equilibrium tidal data to search for the 18.6 year lunar tide and 14 month pole tide. Both tides are clearly evident in the results, and their amplitudes and phases are found to be consistent with a global equilibrium response. Global, monthly <span class="hlt">sea</span> <span class="hlt">level</span> data from outside the Baltic <span class="hlt">sea</span> and Gulf of Bothnia are fitted to global atmospheric pressure data to study the response of the ocean to pressure fluctuations. The response is found to be inverted barometer at periods greater than two months. Global averages of tide gauge data, after correcting for the effects of post glacial rebound on individual station records, reveal an increase in <span class="hlt">sea</span> <span class="hlt">level</span> over the last 80 years of between 1.1 mm/yr and 1.9 mm/yr.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.H33I1734O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.H33I1734O"><span>Method for Assessing Impacts of Global <span class="hlt">Sea</span> <span class="hlt">Level</span> Rise on Navigation Gate Operations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Obrien, P. S.; White, K. D.; Friedman, D.</p> <p>2015-12-01</p> <p>Coastal navigation infrastructure may be highly vulnerable to changing climate, including increasing <span class="hlt">sea</span> <span class="hlt">levels</span> and altered frequency and intensity of coastal storms. Future gate operations impacted by global <span class="hlt">sea</span> <span class="hlt">level</span> rise will pose unique challenges, especially for structures 50 years and older. Our approach is to estimate future changes in gate operational frequency based on a bootstrapping method to forecast future water <span class="hlt">levels</span>. A case study will be presented to determine future changes in frequency of operations over the next 100 years. A statistical model in the R programming language was developed to apply future <span class="hlt">sea</span> <span class="hlt">level</span> rise projections using the three <span class="hlt">sea</span> <span class="hlt">level</span> rise scenarios prescribed by USACE Engineer Regulation ER 1100-2-8162. Information derived from the case study will help forecast changes in operational costs caused by increased gate operations and inform timing of decisions on adaptation <span class="hlt">measures</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010JGRC..11512016G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010JGRC..11512016G"><span>Steric and mass-induced <span class="hlt">sea</span> <span class="hlt">level</span> variations in the Mediterranean <span class="hlt">Sea</span> revisited</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>GarcíA-GarcíA, D.; Chao, B. F.; Boy, J.-P.</p> <p>2010-12-01</p> <p>The total <span class="hlt">sea</span> <span class="hlt">level</span> variation (SLV) is the combination of steric and mass-induced SLV, whose exact shares are key to understanding the oceanic response to climate system changes. Total SLV can be observed by radar altimetry satellites such as TOPEX/POSEIDON and Jason 1/2. The steric SLV can be computed through temperature and salinity profiles from in situ <span class="hlt">measurements</span> or from ocean general circulation models (OGCM), which can assimilate the said observations. The mass-induced SLV can be estimated from its time-variable gravity (TVG) signals. We revisit this problem in the Mediterranean <span class="hlt">Sea</span> estimating the observed, steric, and mass-induced SLV, for the latter we analyze the latest TVG data set from the GRACE (Gravity Recovery and Climate Experiment) satellite mission launched in 2002, which is 3.5 times longer than in previous studies, with the application of a two-stage anisotropic filter to reduce the noise in high-degree and -order spherical harmonic coefficients. We confirm that the intra-annual total SLV are only produced by water mass changes, a fact explained in the literature as a result of the wind field around the Gibraltar Strait. The steric SLV estimated from the residual of "altimetry minus GRACE" agrees in phase with that estimated from OGCMs and in situ <span class="hlt">measurements</span>, although showing a higher amplitude. The net water fluxes through both the straits of Gibraltar and Sicily have also been estimated accordingly.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996JMS.....7..267W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996JMS.....7..267W"><span>The response of tropical Australian estuaries to a <span class="hlt">sea</span> <span class="hlt">level</span> rise</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wolanski, E.; Chappell, J.</p> <p>1996-02-01</p> <p>Estuaries in tropical Australia have a low sediment yield (about 5-20 tonnes km -2 yr -1). The estuaries formed when rising post-glacial <span class="hlt">sea</span> <span class="hlt">level</span> invaded coastal valleys 7 to 9000 years ago. Geomorphological and stratigraphic data show that mangrove swamps developed on the flooded plains and in some cases their substrate kept pace with the rising <span class="hlt">sea</span> <span class="hlt">level</span>. The bulk of the sediment originated from the <span class="hlt">sea</span>. When <span class="hlt">sea</span> <span class="hlt">level</span> stabilised, 6000 years ago, the flood plains prograded seaward. The channels now are generally stable and in some cases are inherited from the progradation phase. The response of these estuaries to a <span class="hlt">sea</span> <span class="hlt">level</span> rise may be inferred both from their evolution during post glacial <span class="hlt">sea</span> <span class="hlt">level</span> rise and from hydrodynamics-sedimentological models calibrated against <span class="hlt">measurements</span> of tidal processes. This was undertaken for Coral Creek, the South Alligator River and the Norman River in north Australia. Modelling indicates that a future <span class="hlt">sea</span> <span class="hlt">level</span> rise will generate changes in the dynamics and channel dimensions which mimic post glacial changes. In the macrotidal South Alligator the floodplain will revert to mangrove, the mouth region will widen and sediment will move upstream and onto the floodplain. In the mesotidal, diurnal Norman the channel will widen throughout and sediment will be transported seawards. In Coral Creek the mangrove will retreat landwards.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMGC43D0968T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMGC43D0968T"><span>On Early Holocene Ice-Sheet/<span class="hlt">Sea-Level</span> Interactions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tornqvist, T. E.; Hijma, M.</p> <p>2011-12-01</p> <p>Early Holocene <span class="hlt">sea-level</span> change constitutes an imperfect, yet potentially valuable analog for future <span class="hlt">sea-level</span> rise, given the rapidly disintegrating land-based ice under climate conditions of high-latitude Northern Hemisphere warming. The associated rates of eustatic <span class="hlt">sea-level</span> rise (cm/yr order of magnitude) fall within the range of predictions for the latter part of the next century. However, the early Holocene eustatic <span class="hlt">sea-level</span> history is otherwise rather poorly understood. Recent impetus has been provided by new records of both relative <span class="hlt">sea-level</span> (RSL) change and ice-sheet retreat that are sometimes difficult to reconcile in terms of timing and magnitude of change. We first summarize the state-of-the-art on early Holocene <span class="hlt">sea-level</span> change and then identify key near-term research needs. Recent studies have identified a number of decimeter to meter-scale <span class="hlt">sea-level</span> jumps, several of which have been linked to catastrophic drainage of proglacial Lake Agassiz and the 8.2 ka cooling event. It is increasingly clear that this occurred by means of two successive jumps, separated by up to a few centuries, and only the latter (and final) one coinciding with the 8.2 ka climate event proper. We show that a considerable research effort, including near-field, intermediate-field, and far-field localities across the globe is needed to fully understand the timing and magnitude of these <span class="hlt">sea-level</span> jumps. Accomplishing this goal would in addition offer a unique opportunity for rigorous testing of gravitational theory and associated <span class="hlt">sea-level</span> fingerprinting that plays a critical role in predicting future <span class="hlt">sea-level</span> change. A more enigmatic <span class="hlt">sea-level</span> jump that has been identified around 7.6 ka has received renewed interest both by means of new RSL data from Fennoscandia and reconstructions of Laurentide Ice Sheet retreat. However, the proposed ~5 m abrupt rise in eustatic <span class="hlt">sea</span> <span class="hlt">level</span> cannot be detected in relatively nearby, detailed RSL records from NW Europe, thus presenting a</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003AGUFMPP12A0233B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003AGUFMPP12A0233B"><span><span class="hlt">Sea-level</span> and the `Stage 11 Problem`</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bowen, D. Q.</p> <p>2003-12-01</p> <p>Estimating an approximate relative <span class="hlt">sea</span> <span class="hlt">level</span> for oxygen isotope stage 11 may have a critical bearing on a solution to the `stage 11 problem` that identifies the mismatch between low eccentricity forcing and the disproportionate ice volume response - that also includes a relative <span class="hlt">sea</span> <span class="hlt">level</span> response. The perennial problem of separating ice volume from temperature effects has hampered attempts to estimate <span class="hlt">sea</span> <span class="hlt">level</span> from delta 18O data sets, even for younger odd numbered stages when comparisons with U-series ages on corals are available. Stage 11 <span class="hlt">sea</span> <span class="hlt">levels</span> on `stable` and uplifting coasts are recognised from geomorphic features such as terraces and shoreline angles, sediments and corals, and yield a range of estimates from over 20 m to just below present <span class="hlt">sea</span> <span class="hlt">level</span>. Given that the 413 ka Milankovitch pacing provides similar orbital configurations for stage 11 and the Holocene some interest attaches to the potential <span class="hlt">sea-level</span> similarity between them, especially for the future Holocene. Attempts to derive a stage 11 <span class="hlt">sea</span> <span class="hlt">level</span> from coasts uplifting at different rates have used `uplift correction graphs` or uplift correction equations, but a major handicap is the dearth of appropriate geochronologic ages both for stage 11 and substage 5e (5.5) - the base line for estimating average uplift rates. Different estimates for the age of stage 11 and 5e (5.5), and the duration of 5e, have yielded a range of estimates. Earlier estimates relied on single locations or regional evidence, but it is probably misleading to rely on these. To combat this several world-wide locations are assembled and, using locality-specific data, provide a mean estimate for the stage 11 <span class="hlt">sea</span> <span class="hlt">level</span> of 11 m, plus-minus 10 m. But by applying a set of standardised parameters (including the peak <span class="hlt">sea</span> <span class="hlt">level</span> at 402 ka - event 11.3 of the Bassinott time scale) the mean <span class="hlt">sea</span> <span class="hlt">level</span> for stage 11 emerges as 2 m plus-minus 7 m. This closes the gap between inferences from delta 18O variability, the latest of which point</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70141641','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70141641"><span><span class="hlt">Sea-level</span>-induced seismicity and submarine landslide occurrence</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Brothers, Daniel S.; Luttrell, Karen M.; Chaytor, Jason D.</p> <p>2013-01-01</p> <p>The temporal coincidence between rapid late Pleistocene <span class="hlt">sea-level</span> rise and large-scale slope failures is widely documented. Nevertheless, the physical mechanisms that link these phenomena are poorly understood, particularly along nonglaciated margins. Here we investigate the causal relationships between rapid <span class="hlt">sea-level</span> rise, flexural stress loading, and increased seismicity rates along passive margins. We find that Coulomb failure stress across fault systems of passive continental margins may have increased more than 1 MPa during rapid late Pleistocene–early Holocene <span class="hlt">sea-level</span> rise, an amount sufficient to trigger fault reactivation and rupture. These results suggest that <span class="hlt">sea</span>-level–modulated seismicity may have contributed to a number of poorly understood but widely observed phenomena, including (1) increased frequency of large-scale submarine landslides during rapid, late Pleistocene <span class="hlt">sea-level</span> rise; (2) emplacement of coarse-grained mass transport deposits on deep-<span class="hlt">sea</span> fans during the early stages of marine transgression; and (3) the unroofing and release of methane gas sequestered in continental slope sediments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013DyAtO..64....1G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013DyAtO..64....1G"><span>The statistical relation of <span class="hlt">sea-level</span> and temperature revisited</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grassi, Stefano; Hillebrand, Eric; Ventosa-Santaulària, Daniel</p> <p>2013-11-01</p> <p>We propose a semi-empirical model for the relation between global mean surface temperature and global <span class="hlt">sea-levels</span>. In contradistinction to earlier approaches to this problem, the model allows for valid statistical inference and joint estimation of trend components and interaction term of temperature and <span class="hlt">sea-level</span>. Estimation of the model on the data set used in Rahmstorf (2007) yields a proportionality coefficient of 4.6 mm/year per °C at a one-sided significance <span class="hlt">level</span> of 7.6 percent or higher. Long-term simulations of the model result in a two-sided 90-percent confidence interval for the <span class="hlt">sea-level</span> rise in the year 2100 of [15 cm, 150 cm] above the 1990 <span class="hlt">level</span>. This is a wider margin of error than was reported in the previous literature, and it reflects the substantial uncertainty in relating two trending time series.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1992GMS....69..133T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992GMS....69..133T"><span><span class="hlt">Sea</span> <span class="hlt">level</span> variations in the northeast Atlantic from GEOSAT</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tokmakian, R.; Challenor, P. G.</p> <p></p> <p>This paper discusses observations of <span class="hlt">sea</span> <span class="hlt">level</span> in the Northeast Atlantic between 5° and 45° west and 25° and 45° north as <span class="hlt">measured</span> by GEOSAT. Two years of GEOSAT exact repeal data were collocated on a 0.06 degree grid with the mean <span class="hlt">sea</span> surface removed by the along track difference method. Tthe orbit error was extracted by a crossover analysis technique. The data set was then interpolated with a Successive Correction Method onto 15 day, 0.5 degree maps to produce 47 residual height fields to be analyzed using complex empirical orthogonal functions. The results show that there is a region of high variability in the northwest comer reflecting the Gulf Stream extension and a region of medium variability at approximately 35 degrees north reflecting the Azores Current. The variability changes only slightly throughout the year, with the winter season being the highest. The complex EOFs do not show an annual signal, but do show some wave-like feature of approximately a 225 day period propagating westward.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19850027742','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850027742"><span>Longitudinal development of muons in large air showers studies from the arrival time distributions <span class="hlt">measured</span> at 900m above <span class="hlt">sea</span> <span class="hlt">level</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kakimoto, F.; Tsuchimoto, I.; Enoki, T.; Suga, K.; Nishi, K.</p> <p>1985-01-01</p> <p>The arrival time distributions of muons with energies above 1.0GeV and 0.5GeV have been <span class="hlt">measured</span> in the Akeno air-shower array to study the longitudinal development of muons in air showers with primary energies in the range 10 to the 17th power to 10 to the 18th power ev. The average rise times of muons with energies above 1.0GeV at large core distances are consistent with those expected from very high multiplicity models and, on the contrary, with those expected from the low multiplicity models at small core distances. This implies that the longitudinal development at atmospheric depth smaller than 500 cm square is very fast and that at larger atmospheric depths is rather slow.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRG..120.1741W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRG..120.1741W"><span>Revisiting the role of CH4 emissions from alpine wetlands on the Tibetan Plateau: Evidence from two in situ <span class="hlt">measurements</span> at 4758 and 4320 m above <span class="hlt">sea</span> <span class="hlt">level</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wei, Da; Xu-Ri; Tarchen, Tenzin; Dai, Dongxue; Wang, Yuesi; Wang, Yinghong</p> <p>2015-09-01</p> <p>The alpine wetlands on the Tibetan Plateau (TP) constitute 30% of China's wetlands, and previous studies have considered these wetlands to be important sources of CH4, based on several swamp <span class="hlt">measurements</span> from the eastern edges of the plateau. However, the alpine wetlands consist of both swamps (9.5%) and swamp meadows (79.8%). In this study, the CH4 fluxes of a swamp meadow and a swamp were determined. The results showed that the swamp meadow emitted much less CH4 (130.8 ± 123.9 µg m-2 h-1) than the swamp (2795.2 ± 796.4 µg m-2 h-1). The CH4 fluxes within the swamp meadow showed distinct microscale spatial heterogeneity: the hollow terrain released CH4, while the hummocks absorbed CH4; this pattern was explained well by soil moisture. The CH4 emissions in the swamp meadow were highly sensitive to soil temperature variation (Q10 = 3.62), while they were more sensitive to soil moisture in the swamp. By summarizing existing <span class="hlt">measurements</span>, and considering the differences in CH4 emissions from swamp meadows and swamps, the emissions of CH4 from alpine wetlands across the TP were recalculated to range from 0.215 to 0.412 Tg CH4 a-1, lower than previous studies. By comparison, the CH4 uptake by nonwetland ecosystems ranges from -0.68 to -0.53 Tg CH4 a-1. Therefore, this study conveys a notion that the alpine wetlands on the TP may not be significant CH4 sources. However, further studies are needed to reduce the uncertainty regarding CH4 emissions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015QuRes..84...69L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015QuRes..84...69L"><span>Late Quaternary <span class="hlt">sea-level</span> changes of the Persian Gulf</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lokier, Stephen W.; Bateman, Mark D.; Larkin, Nigel R.; Rye, Philip; Stewart, John R.</p> <p>2015-07-01</p> <p>Late Quaternary reflooding of the Persian Gulf climaxed with the mid-Holocene highstand previously variously dated between 6 and 3.4 ka. Examination of the stratigraphic and paleoenvironmental context of a mid-Holocene whale beaching allows us to accurately constrain the timing of the transgressive, highstand and regressive phases of the mid- to late Holocene <span class="hlt">sea-level</span> highstand in the Persian Gulf. Mid-Holocene transgression of the Gulf surpassed today's <span class="hlt">sea</span> <span class="hlt">level</span> by 7100-6890 cal yr BP, attaining a highstand of > 1 m above current <span class="hlt">sea</span> <span class="hlt">level</span> shortly after 5290-4570 cal yr BP before falling back to current <span class="hlt">levels</span> by 1440-1170 cal yr BP. The cetacean beached into an intertidal hardground pond during the transgressive phase (5300-4960 cal yr BP) with continued transgression interring the skeleton in shallow-subtidal sediments. Subsequent relative <span class="hlt">sea-level</span> fall produced a forced regression with consequent progradation of the coastal system. These new ages refine previously reported timings for the mid- to late Holocene <span class="hlt">sea-level</span> highstand published for other regions. By so doing, they allow us to constrain the timing of this correlatable global eustatic event more accurately.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JGRC..118.3999M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JGRC..118.3999M"><span>A nonstationary analysis for the Northern Adriatic extreme <span class="hlt">sea</span> <span class="hlt">levels</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Masina, Marinella; Lamberti, Alberto</p> <p>2013-09-01</p> <p>The historical data from the Trieste, Venice, Porto Corsini, and Rimini tide gauges have been used to investigate the spatial and temporal changes in extreme high water <span class="hlt">levels</span> in the Northern Adriatic. A detailed analysis of annual mean <span class="hlt">sea</span> <span class="hlt">level</span> evolution at the three longest operating stations shows a coherent behavior both on a regional and global scale. A slight increase in magnitude of extreme water elevations, after the removal of the regularized annual mean <span class="hlt">sea</span> <span class="hlt">level</span> necessary to eliminate the effect of local subsidence and <span class="hlt">sea</span> <span class="hlt">level</span> rise, is found at the Venice and Porto Corsini stations. It seems to be mainly associated with a wind regime change occurred in the 1990s, due to an intensification of Bora wind events after their decrease in frequency and intensity during the second half of the 20th century. The extreme values, adjusted for the annual mean <span class="hlt">sea</span> <span class="hlt">level</span> trend, are modeled using a time-dependent GEV distribution. The inclusion of seasonality in the GEV parameters considerably improves the data fitting. The interannual fluctuations of the detrended monthly maxima exhibit a significant correlation with the variability of the large-scale atmospheric circulation represented by the North Atlantic Oscillation and Arctic Oscillation indices. The different coast exposure to the Bora and Sirocco winds and their seasonal character explain the various seasonal patterns of extreme <span class="hlt">sea</span> <span class="hlt">levels</span> observed at the tide gauges considered in the present analysis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17813199','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17813199"><span><span class="hlt">Sea</span> <span class="hlt">level</span> at southern california: a decadal fluctuation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Namias, J; Chi Kan Huang, J</p> <p>1972-07-28</p> <p>The winter mean height of <span class="hlt">sea</span> <span class="hlt">level</span> at southern California rose 5.6 centimeters between the periods 1948-1957 and 1958-1969. These periods correspond to two fairly coherent large-scale climatic regimes with different air-<span class="hlt">sea</span> coupling, which were previously identified. The rise was mainly due to a change in the thermohaline structure of the water as a result of changes in prevailing winds.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26912856','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26912856"><span>A decade of <span class="hlt">sea</span> <span class="hlt">level</span> rise slowed by climate-driven hydrology.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Reager, J T; Gardner, A S; Famiglietti, J S; Wiese, D N; Eicker, A; Lo, M-H</p> <p>2016-02-12</p> <p>Climate-driven changes in land water storage and their contributions to <span class="hlt">sea</span> <span class="hlt">level</span> rise have been absent from Intergovernmental Panel on Climate Change <span class="hlt">sea</span> <span class="hlt">level</span> budgets owing to observational challenges. Recent advances in satellite <span class="hlt">measurement</span> of time-variable gravity combined with reconciled global glacier loss estimates enable a disaggregation of continental land mass changes and a quantification of this term. We found that between 2002 and 2014, climate variability resulted in an additional 3200 ± 900 gigatons of water being stored on land. This gain partially offset water losses from ice sheets, glaciers, and groundwater pumping, slowing the rate of <span class="hlt">sea</span> <span class="hlt">level</span> rise by 0.71 ± 0.20 millimeters per year. These findings highlight the importance of climate-driven changes in hydrology when assigning attribution to decadal changes in <span class="hlt">sea</span> <span class="hlt">level</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70174403','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70174403"><span>Processes contributing to resilience of coastal wetlands to <span class="hlt">sea-level</span> rise</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Stagg, Camille L.; Krauss, Ken W.; Cahoon, Donald R.; Cormier, Nicole; Conner, William H.; Swarzenski, Christopher M.</p> <p>2016-01-01</p> <p>The objectives of this study were to identify processes that contribute to resilience of coastal wetlands subject to rising <span class="hlt">sea</span> <span class="hlt">levels</span> and to determine whether the relative contribution of these processes varies across different wetland community types. We assessed the resilience of wetlands to <span class="hlt">sea-level</span> rise along a transitional gradient from tidal freshwater forested wetland (TFFW) to marsh by <span class="hlt">measuring</span> processes controlling wetland elevation. We found that, over 5 years of <span class="hlt">measurement</span>, TFFWs were resilient, although some marginally, and oligohaline marshes exhibited robust resilience to <span class="hlt">sea-level</span> rise. We identified fundamental differences in how resilience is maintained across wetland community types, which have important implications for management activities that aim to restore or conserve resilient systems. We showed that the relative importance of surface and subsurface processes in controlling wetland surface elevation change differed between TFFWs and oligohaline marshes. The marshes had significantly higher rates of surface accretion than the TFFWs, and in the marshes, surface accretion was the primary contributor to elevation change. In contrast, elevation change in TFFWs was more heavily influenced by subsurface processes, such as root zone expansion or compaction, which played an important role in determining resilience of TFFWs to rising <span class="hlt">sea</span> <span class="hlt">level</span>. When root zone contributions were removed statistically from comparisons between relative <span class="hlt">sea-level</span> rise and surface elevation change, sites that previously had elevation rate deficits showed a surplus. Therefore, assessments of wetland resilience that do not include subsurface processes will likely misjudge vulnerability to <span class="hlt">sea-level</span> rise.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.7389N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.7389N"><span>Contribution of climate forcing to <span class="hlt">sea</span> <span class="hlt">level</span> variations in the Mediterranean <span class="hlt">Sea</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Natsiopoulos, Dimitrios A.; Vergos, Georgios S.; Tziavos, Ilias N.</p> <p>2016-04-01</p> <p>With the availability of an abundance of earth observation data from satellite altimetry missions as well as those from the ENVISAT and CRYOSAT-2 satellites, monitoring of the <span class="hlt">sea</span> <span class="hlt">level</span> variations is gaining increased importance. In this work, altimetric data sets from the satellite remote sensing missions of ENVISAT and CRYOSAT-2 have been used to study the variations of the Mediterranean <span class="hlt">sea</span> <span class="hlt">level</span>. Alongside, a correlation analysis of <span class="hlt">Sea</span> <span class="hlt">Level</span> Anomalies (SLAs) with global and regional climatic indexes that influence the ocean state, has been carried out as well. The raw data used were SLAs from the respective altimetric missions, acquired by the on-board altimeters from the ENVISAT satellite for seven consecutive years (2003-2009) and from the CRYOSAT-2 satellite for six consecutive years (2010-2015). Three oscillation indexes have been investigated, as representative of climate-change and seasonal forcing on the <span class="hlt">sea</span> <span class="hlt">level</span>. The first one was the well-known Southern Oscillation Index (SOI), the next one the North Atlantic Oscillation (NAO) index and the third, being primarily more representative of the Mediterranean <span class="hlt">sea</span> state, was the Mediterranean Oscillation Index (MOI). The possible correlation is investigated in both monthly and annual scales, while a regional multiple regression and a principal component analysis (PCA) between the SLAs and oscillation indexes is carried out. Multiple regression and PCA have been used as tools in order to deduce possible correlations between the Mediterranean <span class="hlt">sea</span> <span class="hlt">level</span> variations and the aforementioned oscillation indexes, under the assumption that SLA variations are driven by steric forcing. Finally, evidence of the <span class="hlt">sea</span> <span class="hlt">level</span> cyclo-stationarity in the Mediterranean <span class="hlt">Sea</span> is deduced from the analysis of empirically derived covariance functions at monthly intervals from the available SLA data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19830041107&hterms=global+cooling&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dglobal%2Bcooling','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19830041107&hterms=global+cooling&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dglobal%2Bcooling"><span>Global mean <span class="hlt">sea</span> <span class="hlt">level</span> - Indicator of climate change</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Robock, A.; Hansen, J.; Gornitz, V.; Lebedeff, S.; Moore, E.; Etkins, R.; Epstein, E.</p> <p>1983-01-01</p> <p>A critical discussion is presented on the use by Etkins and Epstein (1982) of combined surface air temperature and <span class="hlt">sea</span> <span class="hlt">level</span> time series to draw conclusions concerning the discharge of the polar ice sheets. It is objected by Robock that they used Northern Hemisphere land surface air temperature records which are unrepresentative of global <span class="hlt">sea</span> surface temperature, and he suggests that externally imposed volcanic dust and CO2 forcings can adequately account for observed temperature changes over the last century, with global <span class="hlt">sea</span> <span class="hlt">level</span> changing in passive response to <span class="hlt">sea</span> change as a result of thermal expansion. Hansen et al. adduce evidence for global cooling due to ice discharge that has not exceeded a few hundredths of a degree centigrade in the last century, precluding any importance of this phenomenon in the interpretation of global mean temperature trends for this period. Etkins and Epstein reply that since their 1982 report additional evidence has emerged for the hypothesis that the polar ice caps are diminishing. It is reasserted that each of the indices discussed, including global mean <span class="hlt">sea</span> surface temperature and <span class="hlt">sea</span> <span class="hlt">level</span>, polar ice sheet mass balance, water mass characteristics, and the spin rate and axis of rotation displacement of the earth, are physically linked and can be systematically monitored, as is currently being planned under the auspices of the National Climate Program.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMPP11E..07C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMPP11E..07C"><span>Revisiting Tectonic Corrections Applied to Pleistocene <span class="hlt">Sea-Level</span> Highstands</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Creveling, J. R.; Mitrovica, J. X.; Hay, C.; Austermann, J.; Kopp, R. E.</p> <p>2015-12-01</p> <p>The robustness of stratigraphic- and geomorphic-based inferences of Quaternary peak interglacial <span class="hlt">sea</span> <span class="hlt">levels</span> — and equivalent minimum continental ice volumes — depends on the accuracy with which highstand markers can be corrected for vertical tectonic displacement. For sites that preserve a Marine Isotope Stage (MIS) 5e <span class="hlt">sea-level</span> highstand marker, the customary method for estimating tectonic uplift/subsidence rate computes the difference between the local elevation of the highstand marker and a reference eustatic (i.e., global mean) MIS 5e <span class="hlt">sea-level</span> height, typically assumed to be +6 m, and then divides this height difference by the age of the highstand marker. This rate is then applied to correct the elevation of other observed <span class="hlt">sea-level</span> markers at that site for tectonic displacement. Subtracting a reference eustatic value from a local MIS 5e highstand marker elevation introduces two potentially significant errors. First, the commonly adopted peak eustatic MIS 5e <span class="hlt">sea-level</span> value (i.e., +6 m) is likely too low; recent studies concluded that MIS 5e peak eustatic <span class="hlt">sea</span> <span class="hlt">level</span> was ~6-9 m. Second, local peak MIS 5e <span class="hlt">sea</span> <span class="hlt">level</span> was not globally uniform, but instead characterized by significant departures from eustasy due to glacial isostatic adjustment (GIA) in response to successive glacial-interglacial cycles and excess polar ice-sheet melt relative to present day. We present numerical models of GIA that incorporate both of these effects in order to quantify the plausible range in error of previous tectonic corrections. We demonstrate that, even far from melting ice sheets, local peak MIS 5e <span class="hlt">sea</span> <span class="hlt">level</span> may have departed from eustasy by 2-4 m, or more. Thus, adopting an assumed reference eustatic value to estimate tectonic displacement, rather than a site-specific GIA signal, can introduce significant error in estimates of peak eustatic <span class="hlt">sea</span> <span class="hlt">level</span> (and minimum ice volumes) during Quaternary highstands (e.g., MIS 11, MIS 5c and MIS 5a).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.4718Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.4718Z"><span>Long-period <span class="hlt">sea-level</span> variations in the Mediterranean</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zerbini, Susanna; Raicich, Fabio; Bruni, Sara; del Conte, Sara; Errico, Maddalena; Prati, Claudio; Santi, Efisio</p> <p>2016-04-01</p> <p>Since the beginning of its long-lasting lifetime, the Wegener initiative has devoted careful consideration to studying <span class="hlt">sea-level</span> variations/changes across the Mediterranean <span class="hlt">Sea</span>. Our study focuses on several long-period <span class="hlt">sea-level</span> time series (from end of 1800 to 2012) acquired in the Mediterranean by tide gauge stations. In general, the analysis and interpretation of these data sets can provide an important contribution to research on climate change and its impacts. We have analyzed the centennial <span class="hlt">sea-level</span> time series of six fairly well documented tide gauges. They are: Marseille, in France, Alicante in Spain, Genoa, Trieste, Venice and Marina di Ravenna (formerly Porto Corsini), in Italy. The data of the Italian stations of Marina di Ravenna and Venice clearly indicate that land subsidence is responsible for most of the observed rate of relative <span class="hlt">sea</span> <span class="hlt">level</span> rise. It is well known that, in the two areas, subsidence is caused by both natural processes and human activities. For these two stations, using <span class="hlt">levelling</span> data of benchmarks at, and/or close to, the tide gauges, and for the recent years, also GPS and InSAR height time series, modelling of the long-period non-linear behavior of subsidence was successfully accomplished. After removing the land vertical motions, the estimate of the linear long-period <span class="hlt">sea-level</span> rise at all six stations yielded remarkably consistent values, between +1,2 and +1,3 mm/yr, with associated errors ranging from ±0,2 to ±0,3 mm/yr (95% confidence interval), which also account for the statistical autocorrelation of the time series. These trends in the Mediterranean area are lower than the global mean rate of 1,7±0,2 mm/yr (1901-2010) presented by the IPCC in its 5th Assessment Report; however, they are in full agreement with a global mean <span class="hlt">sea-level</span> rise estimate, over the period 1901-1990, recently published by Hay et al. (2015, doi:10.1038/nature14093) and obtained using probabilistic techniques that combine <span class="hlt">sea-level</span> records with physics</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.6186M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.6186M"><span>New and improved data products from the Permanent Service for Mean <span class="hlt">Sea</span> <span class="hlt">Level</span> (PSMSL)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Matthews, Andrew; Bradshaw, Elizabeth; Gordon, Kathy; Hibbert, Angela; Jevrejeva, Svetlana; Rickards, Lesley; Tamisiea, Mark; Williams, Simon</p> <p>2015-04-01</p> <p>The Permanent Service for Mean <span class="hlt">Sea</span> <span class="hlt">Level</span> (PSMSL) is the internationally recognised global <span class="hlt">sea</span> <span class="hlt">level</span> data bank for long term <span class="hlt">sea</span> <span class="hlt">level</span> change information from tide gauges. Established in 1933, the PSMSL continues to be responsible for the collection, publication, analysis and interpretation of <span class="hlt">sea</span> <span class="hlt">level</span> data. The PSMSL operates under the auspices of the International Council for Science (ICSU) and is one of the main data centres for both the International Association for the Physical Sciences of the Oceans (IAPSO) and the International Association of Geodesy (IAG). The PSMSL continues to work closely with other members of the <span class="hlt">sea</span> <span class="hlt">level</span> community through the Intergovernmental Oceanographic Commission's Global <span class="hlt">Sea</span> <span class="hlt">Level</span> Observing System (GLOSS). Currently, the PSMSL data bank for monthly and annual <span class="hlt">sea</span> <span class="hlt">level</span> data holds over 65,000 station-years of data from over 2200 stations. Data from each site are carefully quality controlled and, wherever possible, reduced to a common datum, whose stability is monitored through a network of geodetic benchmarks. Last year, the PSMSL also made available a data bank of <span class="hlt">measurements</span> taken from in-situ ocean bottom pressure recorders from over 60 locations across the globe. Here, we present an overview of the data available at the PSMSL, and describe some of the ongoing work that aims to provide more information to users of our data. In particular, we describe the ongoing work with the Système d'Observation du Niveau des Eaux Littorales (SONEL) to use <span class="hlt">measurements</span> from continuous GNSS records located near tide gauges to provide PSMSL data within a geocentric reference frame. We also highlight changes to the method used to present estimated <span class="hlt">sea</span> <span class="hlt">level</span> trends to account for seasonal cycles and autocorrelation in the data, and provide an estimate of the error of the trend.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.G53A..08T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.G53A..08T"><span>Multiple Geodetic Observations for Identifying Glacial Isostatic Adjustment and the Causes of <span class="hlt">Sea-Level</span> Change</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tamisiea, M. E.; Williams, S. D. P.; Hughes, C. W.; Bingley, R.; Blewitt, G.; Hammond, W. C.; Kreemer, C.</p> <p>2015-12-01</p> <p>Understanding the Earth's and ocean's response to past changes in global ice extent and ocean volume, collectively termed glacial isostatic adjustment (GIA), is necessary for interpreting observations of present-day <span class="hlt">sea</span> <span class="hlt">level</span> change. GIA has the largest effect on <span class="hlt">sea-level</span> observations nearest the locations of the former ice sheets. Under the former loading centers, crustal uplift contributes to a local relative <span class="hlt">sea-level</span> fall while the collapsing forebulge surrounding these centers accentuates a local <span class="hlt">sea-level</span> rise. Some of the longest tide gauge records are in these regions. However, GIA also causes global deformation and geoid changes that introduce systematic differences between global averages of tide gauge and altimetry observations. Clearly accounting for the GIA contribution to <span class="hlt">sea-level</span> change while identifying other present-day contributors is greatly assisted by additional geodetic <span class="hlt">measurements</span>. Time-variable satellite gravity observations highlight the regional GIA signal, on length scales of hundreds of kilometers, while also locating water mass changes on the continents and the oceans. As the spatial density of GNSS observations has increased, it has become easier to discern the regional characteristics of crustal deformation (e.g. Blewitt et al. abstract in U009). Combined, these two observations allow for greater separation of GIA and water mass changes. More importantly for society, though, the regional crustal estimates could be combined with coastal altimetry products to create regional estimates of relative <span class="hlt">sea-level</span> change, the observation most relevant for coastal planning. In this presentation we discuss how the various geodetic <span class="hlt">measurements</span> complement each other and allow us to identify various components of <span class="hlt">sea</span> <span class="hlt">level</span> change, including GIA. We illustrate how the weakness of any individual observation component can be overcome by comparison with the other components. A sustained and global geodetic observing system is essential for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27684043','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27684043"><span>High-resolution tide projections reveal extinction threshold in response to <span class="hlt">sea-level</span> rise.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Field, Christopher R; Bayard, Trina S; Gjerdrum, Carina; Hill, Jason M; Meiman, Susan; Elphick, Chris S</p> <p>2017-05-01</p> <p><span class="hlt">Sea-level</span> rise will affect coastal species worldwide, but models that aim to predict these effects are typically based on simple <span class="hlt">measures</span> of <span class="hlt">sea</span> <span class="hlt">level</span> that do not capture its inherent complexity, especially variation over timescales shorter than 1 year. Coastal species might be most affected, however, by floods that exceed a critical threshold. The frequency and duration of such floods may be more important to population dynamics than mean <span class="hlt">measures</span> of <span class="hlt">sea</span> <span class="hlt">level</span>. In particular, the potential for changes in the frequency and duration of flooding events to result in nonlinear population responses or biological thresholds merits further research, but may require that models incorporate greater resolution in <span class="hlt">sea</span> <span class="hlt">level</span> than is typically used. We created population simulations for a threatened songbird, the saltmarsh sparrow (Ammodramus caudacutus), in a region where <span class="hlt">sea</span> <span class="hlt">level</span> is predictable with high accuracy and precision. We show that incorporating the timing of semidiurnal high tide events throughout the breeding season, including how this timing is affected by mean <span class="hlt">sea-level</span> rise, predicts a reproductive threshold that is likely to cause a rapid demographic shift. This shift is likely to threaten the persistence of saltmarsh sparrows beyond 2060 and could cause extinction as soon as 2035. Neither extinction date nor the population trajectory was sensitive to the emissions scenarios underlying <span class="hlt">sea-level</span> projections, as most of the population decline occurred before scenarios diverge. Our results suggest that the variation and complexity of climate-driven variables could be important for understanding the potential responses of coastal species to <span class="hlt">sea-level</span> rise, especially for species that rely on coastal areas for reproduction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24091830','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24091830"><span>First biological <span class="hlt">measurements</span> of deep-<span class="hlt">sea</span> corals from the Red <span class="hlt">Sea</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Roder, C; Berumen, M L; Bouwmeester, J; Papathanassiou, E; Al-Suwailem, A; Voolstra, C R</p> <p>2013-10-03</p> <p>It is usually assumed that metabolic constraints restrict deep-<span class="hlt">sea</span> corals to cold-water habitats, with 'deep-<span class="hlt">sea</span>' and 'cold-water' corals often used as synonymous. Here we report on the first <span class="hlt">measurements</span> of biological characters of deep-<span class="hlt">sea</span> corals from the central Red <span class="hlt">Sea</span>, where they occur at temperatures exceeding 20°C in highly oligotrophic and oxygen-limited waters. Low respiration rates, low calcification rates, and minimized tissue cover indicate that a reduced metabolism is one of the key adaptations to prevailing environmental conditions. We investigated four sites and encountered six species of which at least two appear to be undescribed. One species is previously reported from the Red <span class="hlt">Sea</span> but occurs in deep cold waters outside the Red <span class="hlt">Sea</span> raising interesting questions about presumed environmental constraints for other deep-<span class="hlt">sea</span> corals. Our findings suggest that the present understanding of deep-<span class="hlt">sea</span> coral persistence and resilience needs to be revisited.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014cosp...40E2277N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014cosp...40E2277N"><span><span class="hlt">Sea</span> <span class="hlt">Level</span> Rise and Subsidence in the Gulf of Thailand</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Niemnil, Sommart</p> <p></p> <p>In the Thailand -EC GEO2TECDI-SONG Project we investigate the <span class="hlt">sea</span> <span class="hlt">level</span> change and vertical land motion in Thailand. First, Bangkok is situated in river delta and average height is closed to <span class="hlt">sea</span> <span class="hlt">level</span>. Second, it is subsiding due to ground water extraction. Third, it is experiencing post-seismic motion due to nearby mega thrust earthquakes and fourth, it suffers from rising of <span class="hlt">sea</span> <span class="hlt">levels</span> due to global climate change. This poses a serious threat on Thai society and economy. Before mitigation methods can be devised we aim at charting, qualifying and quantifying all contributing effects by the use of satellite altimetry, GNSS, InSAR techniques and combining results with the in situ observations like tide gauge and with geophysical modeling. Adding GPS based vertical land motion to the tide gauge <span class="hlt">sea</span> <span class="hlt">level</span> registration reveals the absolute <span class="hlt">sea</span> <span class="hlt">level</span> change, which is nicely confirmed by altimetry. We find an average absolute rise of 3.5 mm/yr + 0.7, but nears mouth of Chao Praya River (Bangkok) and the Mekong delta (Ho Chi Min City), this mounts to 4 to 5 mm/yr, faster than global average. This is reinforced when accounting for the tectonic subsidence that resulted from 2004 9.1Mw Sumatra/Andaman earthquake; from 2005 onwards we find downfall in the order of 10 mm/yr. RADARSAT InSAR analyses show subsidence rates up to 25 mm/yr at many places along coastal Bangkok.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryID=158951','PESTICIDES'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryID=158951"><span>COASTAL SENSITIVITY TO <span class="hlt">SEA</span> <span class="hlt">LEVEL</span> RISE: A FOCUS ON ...</span></a></p> <p><a target="_blank" href="http://www.epa.gov/pesticides/search.htm">EPA Pesticide Factsheets</a></p> <p></p> <p></p> <p>Synthesis and Assessment Product 4.1 will synthesize information from the ongoing mapping efforts by federal and non-federal researchers related to the implications of rising <span class="hlt">sea</span> <span class="hlt">level</span>. It will overlay the various data layers to develop new results made possible by bringing together researchers that are otherwise working independently. Because of time, data, and resource limitations, the synthesis will focus on a contiguous portion of the U.S. coastal zone (New York to North Carolina). The report will also develop a plan for <span class="hlt">sea</span> <span class="hlt">level</span> rise research to answer the questions that are most urgent for near-term decisionmaking. This report will address the implications of <span class="hlt">sea</span> <span class="hlt">level</span> rise on three spatial scales by providing: • A literature review that puts the report within the nationwide context. • Data overlays and a state-of-the-art quantitative assessment concerning coastal elevations, shore erosion, and wetland accretion for a multi-state study area along the U.S. Atlantic Coast: New York to North Carolina. • Qualitative discussions and case studies that document in greater detail the impact of <span class="hlt">sea</span> <span class="hlt">level</span> rise on smaller areas within the mid-Atlantic study area. This report will provide information that supports the specific goal in Chapter 9 of the Strategic Plan for the Climate Change Science Program (CCSP, 2003) to analyze how coastal environmental programs can be improved to adapt to <span class="hlt">sea</span> <span class="hlt">level</span> rise while enhancing economic growth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70182742','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70182742"><span>Cenozoic <span class="hlt">sea</span> <span class="hlt">level</span> and the rise of modern rimmed atolls</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Toomey, Michael; Ashton, Andrew; Raymo, Maureen E.; Perron, J. Taylor</p> <p>2016-01-01</p> <p><span class="hlt">Sea-level</span> records from atolls, potentially spanning the Cenozoic, have been largely overlooked, in part because the processes that control atoll form (reef accretion, carbonate dissolution, sediment transport, vertical motion) are complex and, for many islands, unconstrained on million-year timescales. Here we combine existing observations of atoll morphology and corelog stratigraphy from Enewetak Atoll with a numerical model to (1) constrain the relative rates of subsidence, dissolution and sedimentation that have shaped modern Pacific atolls and (2) construct a record of <span class="hlt">sea</span> <span class="hlt">level</span> over the past 8.5 million years. Both the stratigraphy from Enewetak Atoll (constrained by a subsidence rate of ~ 20 m/Myr) and our numerical modeling results suggest that low <span class="hlt">sea</span> <span class="hlt">levels</span> (50–125 m below present), and presumably bi-polar glaciations, occurred throughout much of the late Miocene, preceding the warmer climate of the Pliocene, when <span class="hlt">sea</span> <span class="hlt">level</span> was higher than present. Carbonate dissolution through the subsequent <span class="hlt">sea-level</span> fall that accompanied the onset of large glacial cycles in the late Pliocene, along with rapid highstand constructional reef growth, likely drove development of the rimmed atoll morphology we see today.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23379951','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23379951"><span>Impact of <span class="hlt">sea</span> <span class="hlt">level</span> rise on tide gate function.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Walsh, Sean; Miskewitz, Robert</p> <p>2013-01-01</p> <p><span class="hlt">Sea</span> <span class="hlt">level</span> rise resulting from climate change and land subsidence is expected to severely impact the duration and associated damage resulting from flooding events in tidal communities. These communities must continuously invest resources for the maintenance of existing structures and installation of new flood prevention infrastructure. Tide gates are a common flood prevention structure for low-lying communities in the tidal zone. Tide gates close during incoming tides to prevent inundation from downstream water propagating inland and open during outgoing tides to drain upland areas. Higher downstream mean <span class="hlt">sea</span> <span class="hlt">level</span> elevations reduce the effectiveness of tide gates by impacting the hydraulics of the system. This project developed a HEC-RAS and HEC-HMS model of an existing tide gate structure and its upland drainage area in the New Jersey Meadowlands to simulate the impact of rising mean <span class="hlt">sea</span> <span class="hlt">level</span> elevations on the tide gate's ability to prevent upstream flooding. Model predictions indicate that <span class="hlt">sea</span> <span class="hlt">level</span> rise will reduce the tide gate effectiveness resulting in longer lasting and deeper flood events. The results indicate that there is a critical point in the <span class="hlt">sea</span> <span class="hlt">level</span> elevation for this local area, beyond which flooding scenarios become dramatically worse and would have a significantly negative impact on the standard of living and ability to do business in one of the most densely populated areas of America.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1616781N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1616781N"><span>Holocene <span class="hlt">sea-level</span> changes in the Falkland Islands</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Newton, Tom; Gehrels, Roland; Daley, Tim; Long, Antony; Bentley, Mike</p> <p>2014-05-01</p> <p>In many locations in the southern hemisphere, relative <span class="hlt">sea</span> <span class="hlt">level</span> (RSL) reached its maximum position during the middle Holocene. This highstand is used by models of glacial isostatic adjustment (GIA) to constrain the melt histories of the large ice sheets, particularly Antarctica. In this paper we present the first Holocene <span class="hlt">sea-level</span> record from the Falkland Islands (Islas Malvinas), an archipelago located on the Patagonian continental shelf about 500 km east of mainland South America at a latitude of ca. 52 degrees. Unlike coastal locations in southernmost South America, Holocene <span class="hlt">sea-level</span> data from the Falklands are not influenced by tectonics, local ice loading effects and large tidal ranges such that GIA and ice-ocean mass flux are the dominant drivers of RSL change. Our study site is a salt marsh located in Swan Inlet in East Falkland, around 50 km southwest of Stanley. This is the largest and best developed salt marsh in the Falkland Islands. Cores were collected in 2005 and 2013. Lithostratigraphic analyses were complemented by analyses of foraminifera, testate amoebae and diatoms to infer palaeoenvironments. The bedrock, a Permian black shale, is overlain by grey-brown organic salt-marsh clay, up to 90 cm thick, which, in a landward direction, is replaced by freshwater organic sediments. Overlying these units are medium-coarse sands with occasional pebbles, up to 115 cm thick, containing tidal flat foraminifera. The sandy unit is erosively overlain by a grey-brown organic salt-marsh peat which extends up to the present surface. Further away from the <span class="hlt">sea</span> this unit is predominantly of freshwater origin. Based on 13 radiocarbon dates we infer that prior to ~9.5 ka <span class="hlt">sea</span> <span class="hlt">level</span> was several metres below present. Under rising <span class="hlt">sea</span> <span class="hlt">levels</span> a salt marsh developed which was suddenly drowned around 8.4 ka, synchronous with a <span class="hlt">sea-level</span> jump known from northern hemisphere locations. Following the drowning, RSL rose to its maximum position around 7 ka, less than 0.5 m above</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014E%26PSL.399...74C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014E%26PSL.399...74C"><span>The <span class="hlt">sea-level</span> fingerprint of a Snowball Earth deglaciation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Creveling, Jessica R.; Mitrovica, Jerry X.</p> <p>2014-08-01</p> <p>Cap dolostones are thought to represent deposition from <span class="hlt">seas</span> transgressing over formerly glaciated continental margins during Marinoan Snowball deglaciation. Nevertheless, facies associations within some cap dolostones indicate that an episode of regional regression punctuated these transgressive sequence tracts. To date, inferences of <span class="hlt">sea-level</span> change during and after the Marinoan Snowball deglaciation have been interpreted using simple, qualitative arguments. In the present study, we explore the full spatio-temporal variability of <span class="hlt">sea-level</span> change during Snowball deglaciation and its aftermath using a gravitationally self-consistent theory that accounts for the deformational, gravitational and rotational perturbations to <span class="hlt">sea</span> <span class="hlt">level</span> on a viscoelastic Earth model. The theory is applied to model Marinoan Snowball deglaciation on a generalized Ediacaran paleogeography with a synthetic continental ice-sheet distribution. We find that <span class="hlt">sea-level</span> change following a synchronous, rapid (2 kyr) collapse of Snowball ice cover will exhibit significant geographic variability, including site-specific histories that are characterized by syn-deglacial <span class="hlt">sea-level</span> fall or stillstand. Moreover, some sites that experience syn-deglacial transgression will continue to experience transgression in the post-deglacial phase. Taken together, these results suggest that <span class="hlt">sea-level</span> change recorded by strata capping Snowball glaciogenic units may reflect a more complicated trajectory than previously thought, including deposition that was not limited to the deglaciation phase. These simulations, as well as others that explore the response to asynchronous melting and deglaciation phases of longer duration, demonstrate that an episode of regional regression interrupting a cap dolostone transgressive sequence tract may reflect one of several processes (or their combination): (1) near field adjustment associated with rapid local melting during an otherwise global hiatus in deglaciation; (2) post</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=average+AND+temperature&pg=3&id=EJ290512','ERIC'); return false;" href="http://eric.ed.gov/?q=average+AND+temperature&pg=3&id=EJ290512"><span>Concerns--High <span class="hlt">Sea</span> <span class="hlt">Levels</span> and Temperatures Seen Next Century.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Ryan, Paul R.</p> <p>1984-01-01</p> <p>A National Research Council committee recently concluded that atmospheric carbon dioxide <span class="hlt">levels</span> will "most likely" double by late in the next century, causing an increase in the earth's average temperature. Effects of the increase on <span class="hlt">sea</span> <span class="hlt">levels</span>, global climate, and other parameters are discussed. (JN)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20000031722','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20000031722"><span>Regional <span class="hlt">Sea</span> <span class="hlt">Level</span> Changes Projected by the NASA/GISS Atmosphere-Ocean Model</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Russell, Gary L.; Gornitz, Vivien; Miller, James R.</p> <p>1999-01-01</p> <p><span class="hlt">Sea</span> <span class="hlt">level</span> has been rising for the past century, and inhabitants of the Earth's coastal regions will want to understand and predict future <span class="hlt">sea</span> <span class="hlt">level</span> changes. In this study we present results from new simulations of the Goddard Institute for Space Studies (GISS) global atmosphere-ocean model from 1950 to 2099. Model results are compared with observed <span class="hlt">sea</span> <span class="hlt">level</span> changes during the past 40 years at 17 coastal stations around the world. Using observed <span class="hlt">levels</span> of greenhouse gases between 1950 and 1990 and a compounded 0.5% annual increase in Co2 after 1990, model projections show that global <span class="hlt">sea</span> <span class="hlt">level</span> <span class="hlt">measured</span> from 1950 will rise by 61 mm in the year 2000, by 212 mm in 2050, and by 408 mm in 2089. By 2089, two thirds of the global <span class="hlt">sea</span> <span class="hlt">level</span> rise will be due to thermal expansion and one third will be due to ocean mass changes. The spatial distribution of <span class="hlt">sea</span> <span class="hlt">level</span> rise is different than that projected by rigid lid ocean models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011EOSTr..92..273F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011EOSTr..92..273F"><span>Rising <span class="hlt">sea</span> <span class="hlt">level</span> may cause decline of fringing coral reefs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Field, Michael E.; Ogston, Andrea S.; Storlazzi, Curt D.</p> <p>2011-08-01</p> <p>Coral reefs are major marine ecosystems and critical resources for marine diversity and fisheries. These ecosystems are widely recognized to be at risk from a number of stressors, and added to those in the past several decades is climate change due to anthropogenically driven increases in atmospheric concentrations of greenhouse gases. Most threatening to most coral reefs are elevated <span class="hlt">sea</span> surface temperatures and increased ocean acidity [e.g., Kleypas et al., 1999; Hoegh-Guldberg et al., 2007], but <span class="hlt">sea</span> <span class="hlt">level</span> rise, another consequence of climate change, is also likely to increase sedimentary processes that potentially interfere with photosynthesis, feeding, recruitment, and other key physiological processes (Figure 1). Anderson et al. [2010] argue compellingly that potential hazardous impacts to coastlines from 21st-century <span class="hlt">sea</span> <span class="hlt">level</span> rise are greatly underestimated, particularly because of the rapid rate of rise. The Intergovernmental Panel on Climate Change estimates that <span class="hlt">sea</span> <span class="hlt">level</span> will rise in the coming century (1990-2090) by 2.2-4.4 millimeters per year, when projected with little contribution from melting ice [Meehl et al., 2007]. New studies indicate that rapid melting of land ice could substantially increase the rate of <span class="hlt">sea</span> <span class="hlt">level</span> rise [Grinsted et al., 2009; Milne et al., 2009].</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70043010','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70043010"><span>Rising <span class="hlt">sea</span> <span class="hlt">level</span> may cause decline of fringing coral reefs</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Field, Michael E.; Ogston, Andrea S.; Storlazzi, Curt D.</p> <p>2011-01-01</p> <p>Coral reefs are major marine ecosystems and critical resources for marine diversity and fisheries. These ecosystems are widely recognized to be at risk from a number of stressors, and added to those in the past several decades is climate change due to anthropogenically driven increases in atmospheric concentrations of greenhouse gases. Most threatening to most coral reefs are elevated <span class="hlt">sea</span> surface temperatures and increased ocean acidity [e.g., Kleypas et al., 1999; Hoegh-Guldberg et al., 2007], but <span class="hlt">sea</span> <span class="hlt">level</span> rise, another consequence of climate change, is also likely to increase sedimentary processes that potentially interfere with photosynthesis, feeding, recruitment, and other key physiological processes (Figure 1). Anderson et al. [2010] argue compellingly that potential hazardous impacts to coastlines from 21st-century <span class="hlt">sea</span> <span class="hlt">level</span> rise are greatly underestimated, particularly because of the rapid rate of rise. The Intergovernmental Panel on Climate Change estimates that <span class="hlt">sea</span> <span class="hlt">level</span> will rise in the coming century (1990–2090) by 2.2–4.4 millimeters per year, when projected with little contribution from melting ice [Meehl et al., 2007]. New studies indicate that rapid melting of land ice could substantially increase the rate of <span class="hlt">sea</span> <span class="hlt">level</span> rise [Grinsted et al., 2009; Milne et al., 2009].</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70036289','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70036289"><span>Rising <span class="hlt">sea</span> <span class="hlt">level</span> may cause decline of fringing coral reefs</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Field, M.E.; Ogston, A.S.; Storlazzi, C.D.</p> <p>2011-01-01</p> <p>Coral reefs are major marine ecosystems and critical resources for marine diversity and fisheries. These ecosystems are widely recognized to be at risk from a number of stressors, and added to those in the past several decades is climate change due to anthropogenically driven increases in atmospheric concentrations of greenhouse gases. Most threatening to most coral reefs are elevated <span class="hlt">sea</span> surface temperatures and increased ocean acidity [e.g., Kleypas et al., 1999; Hoegh-Guldberg et al., 2007], but <span class="hlt">sea</span> <span class="hlt">level</span> rise, another consequence of climate change, is also likely to increase sedimentary processes that potentially interfere with photosynthesis, feeding, recruitment, and other key physiological processes (Figure 1). Anderson et al. [2010] argue compellingly that potential hazardous impacts to coastlines from 21st-century <span class="hlt">sea</span> <span class="hlt">level</span> rise are greatly underestimated, particularly because of the rapid rate of rise. The Intergovernmental Panel on Climate Change estimates that <span class="hlt">sea</span> <span class="hlt">level</span> will rise in the coming century (1990-2090) by 2.2-4.4 millimeters per year, when projected with little contribution from melting ice [Meehl et al., 2007]. New studies indicate that rapid melting of land ice could substantially increase the rate of <span class="hlt">sea</span> <span class="hlt">level</span> rise [Grinsted et al., 2009; Milne et al., 2009].</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Rising+AND+sea+AND+levels&id=EJ389555','ERIC'); return false;" href="http://eric.ed.gov/?q=Rising+AND+sea+AND+levels&id=EJ389555"><span>The Significance of Rising <span class="hlt">Sea</span> <span class="hlt">Levels</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Conway, Gregory J.</p> <p>1989-01-01</p> <p>Describes an activity in which students graph changes in tides and ocean <span class="hlt">levels</span> over a period in order to obtain a visual representation of the changes taking place and their effects upon the Earth. Provides questions for students to answer after construction of the graphs. (RT)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFM.G14A..04P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFM.G14A..04P"><span>Impact of global seismicity on <span class="hlt">sea</span> <span class="hlt">level</span> changes assessment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Piersanti, A.; Melini, D.</p> <p>2006-12-01</p> <p>Seismic events alter the equilibrium state of the solid Earth and perturbate its gravitational field. Consequently, they are also likely to produce <span class="hlt">sea</span> <span class="hlt">level</span> variations. The perturbation of the Earth's gravity field due to internal mass redistribution following a seismic event affects the geoid and it is therefore responsible for a variation in the absolute <span class="hlt">sea</span> <span class="hlt">level</span>. The vertical deformation of the seafloor, together with the geoid change, produces also a relative <span class="hlt">sea</span> <span class="hlt">level</span> change. Here we quantify the contribution of last century global seismic activity to sealevel addressing also the problem of ocean volume conservation and discussing the physical reasons for the particular pattern of rise and fall. Our results show that, though small, the seismic induced signal on relative sealevel is not negligible also on global scale and that, in several extended oceanic regions, it could give an important contribution to the total detected trend.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950046393&hterms=Barometers&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DBarometers','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950046393&hterms=Barometers&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DBarometers"><span>Geosat observations of <span class="hlt">sea</span> <span class="hlt">level</span> response to barometric pressure forcing</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hoar, Timothy J.; Wilson, Clark R.</p> <p>1994-01-01</p> <p>Altimeter and <span class="hlt">sea</span> <span class="hlt">level</span> pressure data from the Geosat mission are analyzed for evidence of inverted barometer responses of <span class="hlt">sea</span> <span class="hlt">level</span> to atmospheric pressure forcing. Estimates of the inverted barometer coefficient are given for a variety of geographic regions and time scales using various orbit error removal strategies. There is some sensitivity to the orbit error removal method, but the estimated coefficients show a clear latitudinal dependence and are generally between -0.5 cm/mbar and -0.9 cm/mbar. The southern oceans respond slightly more like an inverted barometer than the northern oceans for similar latitudes. The regression exhibits significant geographic variability, particularly near major circulation features and in the northern hemisphere. The results suggest that the inverted barometer approximation is resonable over much of the oceans, but that some <span class="hlt">sea</span> <span class="hlt">level</span> variability may be correlated with barometric pressure by means other than the inverted barometer effect.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017E%26ES...52a2065X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017E%26ES...52a2065X"><span>Spatial-temporal analysis of <span class="hlt">sea</span> <span class="hlt">level</span> changes in China <span class="hlt">seas</span> and neighboring oceans by merged altimeter data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xu, Yao; Zhou, Bin; Yu, Zhifeng; Lei, Hui; Sun, Jiamin; Zhu, Xingrui; Liu, Congjin</p> <p>2017-01-01</p> <p>The knowledge of <span class="hlt">sea</span> <span class="hlt">level</span> changes is critical important for social, economic and scientific development in coastal areas. Satellite altimeter makes it possible to observe long term and large scale dynamic changes in the ocean, contiguous shelf <span class="hlt">seas</span> and coastal zone. In this paper, 1993-2015 altimeter data of Topex/Poseidon and its follow-on missions is used to get a time serious of continuous and homogeneous <span class="hlt">sea</span> <span class="hlt">level</span> anomaly gridding product. The <span class="hlt">sea</span> <span class="hlt">level</span> rising rate is 0.39 cm/yr in China <span class="hlt">Seas</span> and the neighboring oceans, 0.37 cm/yr in the Bo and Yellow <span class="hlt">Sea</span>, 0.29 cm/yr in the East China <span class="hlt">Sea</span> and 0.40 cm/yr in the South China <span class="hlt">Sea</span>. The mean <span class="hlt">sea</span> <span class="hlt">level</span> and its rising rate are spatial-temporal non-homogeneous. The mean <span class="hlt">sea</span> <span class="hlt">level</span> shows opposite characteristics in coastal <span class="hlt">seas</span> versus open oceans. The Bo and Yellow <span class="hlt">Sea</span> has the most significant seasonal variability. The results are consistent with in situ data observation by the Nation Ocean Agency of China. The coefficient of variability model is introduced to describe the spatial-temporal variability. Results show that the variability in coastal <span class="hlt">seas</span> is stronger than that in open oceans, especially the <span class="hlt">seas</span> off the entrance area of the river, indicating that the validation of altimeter data is less reasonable in these <span class="hlt">seas</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16..601P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16..601P"><span>The imprint of <span class="hlt">sea-level</span> changes in the Southeastern Iberian continental shelf, Western Mediterranean <span class="hlt">Sea</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pinna, Andrea; Lastras, Galderic; Acosta, Juan; Muñoz, Araceli; Canals, Miquel</p> <p>2014-05-01</p> <p>A detailed morphologic analysis of the Southeastern Iberian continental shelf, Western Mediterranean <span class="hlt">Sea</span>, between the Mar Menor and the Gulf of Almería, based on swath bathymetry data, has revealed a number of seafloor features that we attribute to the imprint of <span class="hlt">sea-level</span> changes since the last glacial maximum. The continental shelf has been divided in four different domains with contrasting characteristics: the Mar Menor sector, the Mazarrón and Vera sector, the Gata Cape shelf and the Gulf of Almería shelf. The Mar Menor sector displays an up to 40 km wide shelf with a very low slope gradient, which contrasts with the Mazarrón and Vera shelf, with a width ranging between 0.4 and 5 km, severely incised by the different branches of the Garrucha submarine canyon. On each of these sectors, a variety of morphologies such as crests and escarpments have been identified. Most of these crests and escarpments can be followed for distances exceeding 15 km, and are located at constant, characteristic water depths. We interpret these structures as the result of relatively short-lived <span class="hlt">sea-level</span> still-stands and thus as palaeo-coastlines. Taking into account subsidence, we have correlated their bathymetric position with published post-MIS-5 Mediterranean <span class="hlt">sea-level</span> evolution curves, allowing the attribution of an approximate age for each interpreted palaeo-coastline. The last <span class="hlt">sea-level</span> regression is partially registered in the smooth Mar Menor shelf, where different crests and escarpments are cut by a LGM palaeo-channel, whereas all the sectors display structures related to the last <span class="hlt">sea-level</span> transgression. The continuity of these structures along all the sectors has allowed reconstructing the evolution of the coastline during the last <span class="hlt">sea-level</span> transgression, and thus inferring the palaeo-landscape of this sector of the Southeastern Iberian coast at different stages since 18 ka BP until the present.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110012963','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110012963"><span>Interferometric System for <span class="hlt">Measuring</span> Thickness of <span class="hlt">Sea</span> Ice</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hussein, Ziad; Jordan, Rolando; McDonald, Kyle; Holt, Benjamin; Huang, John; Kugo, Yasuo; Ishimaru, Akira; Jaruwatanadilok, Semsak; Akins, Torry; Gogineni, Prasad</p> <p>2006-01-01</p> <p>The cryospheric advanced sensor (CAS) is a developmental airborne (and, potentially, spaceborne) radar-based instrumentation system for <span class="hlt">measuring</span> and mapping the thickness of <span class="hlt">sea</span> ice. A planned future version of the system would also provide data on the thickness of snow covering <span class="hlt">sea</span> ice. Frequent <span class="hlt">measurements</span> of the thickness of polar ocean <span class="hlt">sea</span> ice and its snow cover on a synoptic scale are critical to understanding global climate change and ocean circulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.8656L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.8656L"><span>Evaluating future flooding risks by using a probabilistic approach to include wave height distributions in <span class="hlt">sea</span> <span class="hlt">level</span> variations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Leijala, Ulpu; Björkqvist, Jan-Victor; Kahma, Kimmo K.; Johansson, Milla M.; Pellikka, Hilkka; Särkkä, Jani</p> <p>2016-04-01</p> <p>, local land uplift, and changes in the Baltic <span class="hlt">Sea</span> water balance. Wave statistics in turn are based on individual wave buoy <span class="hlt">measurements</span> conducted at several sites on the coast off Helsinki during 2012-2014. The method developed in this study is a new tool for evaluating extreme <span class="hlt">sea</span> <span class="hlt">level</span> events including the effect of high <span class="hlt">sea</span> <span class="hlt">level</span> jointly with high wave height. The method can be applied to any coastal areas where sufficient <span class="hlt">sea</span> <span class="hlt">level</span> and wave data are available. The probabilistic approach used here gives a possibility to evaluate the risk <span class="hlt">levels</span> of different infrastructures on the coast for the present and for the future.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014NatCC...4..493R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014NatCC...4..493R"><span>Oyster reefs can outpace <span class="hlt">sea-level</span> rise</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rodriguez, Antonio B.; Fodrie, F. Joel; Ridge, Justin T.; Lindquist, Niels L.; Theuerkauf, Ethan J.; Coleman, Sara E.; Grabowski, Jonathan H.; Brodeur, Michelle C.; Gittman, Rachel K.; Keller, Danielle A.; Kenworthy, Matthew D.</p> <p>2014-06-01</p> <p>In the high-salinity seaward portions of estuaries, oysters seek refuge from predation, competition and disease in intertidal areas, but this sanctuary will be lost if vertical reef accretion cannot keep pace with <span class="hlt">sea-level</span> rise (SLR). Oyster-reef abundance has already declined ~85% globally over the past 100 years, mainly from over harvesting, making any additional losses due to SLR cause for concern. Before any assessment of reef response to accelerated SLR can be made, direct <span class="hlt">measures</span> of reef growth are necessary. Here, we present direct <span class="hlt">measurements</span> of intertidal oyster-reef growth from cores and terrestrial lidar-derived digital elevation models. On the basis of our <span class="hlt">measurements</span> collected within a mid-Atlantic estuary over a 15-year period, we developed a globally testable empirical model of intertidal oyster-reef accretion. We show that previous estimates of vertical reef growth, based on radiocarbon dates and bathymetric maps, may be greater than one order of magnitude too slow. The intertidal reefs we studied should be able to keep up with any future accelerated rate of SLR (ref. ) and may even benefit from the additional subaqueous space allowing extended vertical accretion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2005/1059/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2005/1059/"><span>Coastal vulnerability assessment of Point Reyes National Seashore (PORE) to <span class="hlt">sea-level</span> rise</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Pendleton, Elizabeth A.; Thieler, E. Robert; Williams, S. Jeffress</p> <p>2006-01-01</p> <p>A coastal vulnerability index (CVI) was used to map the relative vulnerability of the coast to future <span class="hlt">sea-level</span> rise within Point Reyes National Seashore in Northern California. The CVI ranks the following in terms of their physical contribution to <span class="hlt">sea-level</span> rise-related coastal change: geomorphology, regional coastal slope, rate of relative <span class="hlt">sea-level</span> rise, historical shoreline change rates, mean tidal range and mean significant wave height. The rankings for each input variable were combined and an index value calculated for 1-minute grid cells covering the park. The CVI highlights those regions where the physical effects of <span class="hlt">sea-level</span> rise might be the greatest. This approach combines the coastal system's susceptibility to change with its natural ability to adapt to changing environmental conditions, yielding a quantitative, although relative, <span class="hlt">measure</span> of the park's natural vulnerability to the effects of <span class="hlt">sea-level</span> rise. The CVI provides an objective technique for evaluation and long-term planning by scientists and park managers. Point Reyes National Seashore consists of sand and gravel beaches, rock cliffs, sand dune cliffs, and pocket beaches. The areas within Point Reyes that are likely to be most vulnerable to <span class="hlt">sea-level</span> rise are areas of unconsolidated sediment where the coastal slope is lowest and wave energy is high.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996QSRv...15..851S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996QSRv...15..851S"><span>Late mid-Holocene <span class="hlt">sea-level</span> oscillation: A possible cause</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Scott, D. B.; Collins, E. S.</p> <p></p> <p><span class="hlt">Sea</span> <span class="hlt">level</span> oscillated between 5500 and 3500 years ago at Murrells Inlet, South Carolina, Chezzetcook and Baie Verte, Nova Scotia and Montmagny, Quebec. The oscillation is well constrained by foraminiferal marsh zonations in three locations and by diatoms in the fourth one. The implications are: (1) there was a eustatic <span class="hlt">sea-level</span> oscillation of about 2-10 m in the late mid-Holocene on the southeast coast of North America (South Carolina to Quebec) that is not predicted by present geophysical models of relative <span class="hlt">sea-level</span> change; (2) this oscillation coincides with oceanographic cooling on the east coast of Canada that we associate with melting ice; and (3) this <span class="hlt">sea</span>- <span class="hlt">level</span> oscillation/climatic event coincides exactly with the end of pyramid building in Egypt which is suggested to have resulted from a climate change (i.e. drought, cooling). This <span class="hlt">sea-level</span>/climatic change is a prime example of feedback where climatic warming in the mid-Holocene promoted ice melt in the Arctic which subsequently caused climatic cooling by opening up Arctic channels releasing cold water into the Inner Labrador Current that continued to intensify until 4000 years ago. This <span class="hlt">sea-level</span> event may also be the best way of <span class="hlt">measuring</span> when the final ice melted since most estimates of the ages of the last melting are based on end moraine dates in the Arctic which may not coincide with when the last ice actually melted out, since there is no way of dating the final ice positions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2004/1064/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2004/1064/"><span>Coastal vulnerability assessment of Cape Hatteras National Seashore (CAHA) to <span class="hlt">sea-level</span> rise</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Pendleton, Elizabeth A.; Theiler, E. Robert; Williams, S. Jeffress</p> <p>2005-01-01</p> <p>A coastal vulnerability index (CVI) was used to map the relative vulnerability of the coast to future <span class="hlt">sea-level</span> rise within Cape Hatteras National Seashore (CAHA) in North Carolina. The CVI ranks the following in terms of their physical contribution to <span class="hlt">sea-level</span> rise-related coastal change: geomorphology, regional coastal slope, rate of relative <span class="hlt">sea-level</span> rise, historical shoreline change rates, mean tidal range, and mean significant wave height. The rankings for each variable were combined and an index value was calculated for 1-minute grid cells covering the park. The CVI highlights those regions where the physical effects of <span class="hlt">sea-level</span> rise might be the greatest. This approach combines the coastal system's susceptibility to change with its natural ability to adapt to changing environmental conditions, yielding a quantitative, although relative, <span class="hlt">measure</span> of the park's natural vulnerability to the effects of <span class="hlt">sea-level</span> rise. The CVI provides an objective technique for evaluation and long-term planning by scientists and park managers. Cape Hatteras National Seashore consists of stable and washover dominated segments of barrier beach backed by wetland and marsh. The areas within Cape Hatteras that are likely to be most vulnerable to <span class="hlt">sea-level</span> rise are those with the highest occurrence of overwash and the highest rates of shoreline change.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2002/of02-233','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2002/of02-233"><span>Coastal vulnerability assessment of Cape Cod National Seashore to <span class="hlt">sea-level</span> rise</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Hammar-Klose, Erika S.; Pendleton, Elizabeth A.; Thieler, E. Robert; Williams, S. Jeffress</p> <p>2003-01-01</p> <p>A coastal vulnerability index (CVI) was used to map the relative vulnerability of the coast to future <span class="hlt">sea-level</span> rise within the Cape Cod National Seashore (CACO). The CVI ranks the following in terms of their physical contribution to <span class="hlt">sea-level</span> rise-related coastal change: geomorphology, regional coastal slope, rate of relative <span class="hlt">sea-level</span> rise, shoreline change rates, mean tidal range and mean wave height. The rankings for each variable were combined and an index value calculated for 1-minute grid cells covering the park. The CVI highlights those regions where the physical effects of <span class="hlt">sea-level</span> rise might be the greatest. This approach combines the coastal system's susceptibility to change with its natural ability to adapt to changing environmental conditions, yielding a quantitative, although relative, <span class="hlt">measure</span> of the park's natural vulnerability to the effects of <span class="hlt">sea-level</span> rise. CACO consists of high glacial cliffs, beaches, sand spits, and salt marsh wetlands. The areas most vulnerable to <span class="hlt">sea-level</span> rise are those with the lowest regional coastal slopes, geomorphologic types that are susceptible to inundation, and the highest rates of shoreline change. Most of CACO's infrastructure lies on high elevation uplands away from the shore; most high use areas are accessible by foot only. The CVI provides an objective technique for evaluation and long-term planning by scientists and park managers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2004/1090/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2004/1090/"><span>Coastal Vulnerability Assessment of Padre Island National Seashore (PAIS) to <span class="hlt">Sea-Level</span> Rise</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Pendleton, Elizabeth A.; Thieler, E. Robert; Williams, S. Jeffress; Beavers, Rebecca S.</p> <p>2004-01-01</p> <p>A coastal vulnerability index (CVI) was used to map the relative vulnerability of the coast to future <span class="hlt">sea-level</span> rise within Padre Island National Seashore in Texas. The CVI ranks the following in terms of their physical contribution to <span class="hlt">sea-level</span> rise-related coastal change: geomorphology, regional coastal slope, rate of relative <span class="hlt">sea-level</span> rise, shoreline change rates, mean tidal range and mean significant wave height. The rankings for each variable were combined and an index value calculated for 1-minute grid cells covering the park. The CVI highlights those regions where the physical effects of <span class="hlt">sea-level</span> rise might be the greatest. This approach combines the coastal system's susceptibility to change with its natural ability to adapt to changing environmental conditions, yielding a quantitative, although relative, <span class="hlt">measure</span> of the park's natural vulnerability to the effects of <span class="hlt">sea-level</span> rise. The CVI provides an objective technique for evaluation and long-term planning by scientists and park managers. Padre Island National Seashore consists of stable to washover dominated portions of barrier beach backed by wetland, marsh, tidal flat, or grassland. The areas within Padre that are likely to be most vulnerable to <span class="hlt">sea-level</span> rise are those with the highest occurrence of overwash and the highest rates of shoreline change.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2004/1416/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2004/1416/"><span>Coastal vulnerability assessment of Dry Tortugas National Park (DRTO) to <span class="hlt">sea-level</span> rise</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Pendleton, Elizabeth A.; Thieler, E. Robert; Williams, S. Jeffress</p> <p>2005-01-01</p> <p>A coastal vulnerability index (CVI) was used to map the relative vulnerability of the coast to future <span class="hlt">sea-level</span> rise within Dry Tortugas National Park in Florida. The CVI ranks the following in terms of their physical contribution to <span class="hlt">sea-level</span> rise-related coastal change: geomorphology, regional coastal slope, rate of relative <span class="hlt">sea-level</span> rise, historical shoreline change rates, mean tidal range and mean significant wave height. The rankings for each input variable were combined and an index value calculated for 1-minute grid cells covering the park. The CVI highlights those regions where the physical effects of <span class="hlt">sea-level</span> rise might be the greatest. This approach combines the coastal system's susceptibility to change with its natural ability to adapt to changing environmental conditions, yielding a quantitative, although relative, <span class="hlt">measure</span> of the park's natural vulnerability to the effects of <span class="hlt">sea-level</span> rise. The CVI provides an objective technique for evaluation and long-term planning by scientists and park managers. Dry Tortugas National Park (DRTO) consists of relatively stable to washover-dominated portions of carbonate beach and man-made fortification. The areas within Dry Tortugas that are likely to be most vulnerable to <span class="hlt">sea-level</span> rise are those with the highest rates of shoreline erosion and the highest wave energy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2004/1196/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2004/1196/"><span>Coastal vulnerability assessment of Cumberland Island National Seashore (CUIS) to <span class="hlt">sea-level</span> rise</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Pendleton, Elizabeth A.; Thieler, E. Robert; Jeffress Williams, S.</p> <p>2004-01-01</p> <p>A coastal vulnerability index (CVI) was used to map the relative vulnerability of the coast to future <span class="hlt">sea-level</span> rise within Cumberland Island National Seashore in Georgia. The CVI ranks the following in terms of their physical contribution to <span class="hlt">sea-level</span> rise-related coastal change: geomorphology, regional coastal slope, rate of relative <span class="hlt">sea-level</span> rise, historical shoreline change rates, mean tidal range and mean significant wave height. The rankings for each input variable were combined and an index value calculated for 1-minute grid cells covering the park. The CVI highlights those regions where the physical effects of <span class="hlt">sea-level</span> rise might be the greatest. This approach combines the coastal system's susceptibility to change with its natural ability to adapt to changing environmental conditions, yielding a quantitative, although relative, <span class="hlt">measure</span> of the park's natural vulnerability to the effects of <span class="hlt">sea-level</span> rise. The CVI provides an objective technique for evaluation and long-term planning by scientists and park managers. Cumberland Island National Seashore consists of stable to washover-dominated portions of barrier beach backed by wetland, marsh, mudflat and tidal creek. The areas within Cumberland that are likely to be most vulnerable to <span class="hlt">sea-level</span> rise are those with the lowest foredune ridge and highest rates of shoreline erosion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2004/1021/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2004/1021/"><span>Coastal vulnerability assessment of Olympic National Park to <span class="hlt">sea-level</span> rise</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Pendleton, Elizabeth A.; Hammar-Klose, Erika S.; Thieler, E. Robert; Williams, S. Jeffress</p> <p>2004-01-01</p> <p>A coastal vulnerability index (CVI) was used to map the relative vulnerability of the coast to future <span class="hlt">sea-level</span> rise within Olympic National Park (OLYM), Washington. The CVI scores the following in terms of their physical contribution to <span class="hlt">sea-level</span> rise-related coastal change: geomorphology, regional coastal slope, rate of relative <span class="hlt">sea-level</span> rise, shoreline change rates, mean tidal range and mean wave height. The rankings for each variable were combined and an index value calculated for 1-minute grid cells covering the park. The CVI highlights those regions where the physical effects of <span class="hlt">sea-level</span> rise might be the greatest. This approach combines the coastal system's susceptibility to change with its natural ability to adapt to changing environmental conditions, yielding a quantitative, although relative, <span class="hlt">measure</span> of the park's natural vulnerability to the effects of <span class="hlt">sea-level</span> rise. The CVI provides an objective technique for evaluation and long-term planning by scientists and park managers. The Olympic National Park coast consists of rocky headlands, pocket beaches, glacial-fluvial features, and sand and gravel beaches. The Olympic coastline that is most vulnerable to <span class="hlt">sea-level</span> rise are beaches in gently sloping areas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2004/1020/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2004/1020/"><span>Coastal vulnerability assessment of Assateague Island National Seashore (ASIS) to <span class="hlt">sea-level</span> rise</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Pendleton, Elizabeth A.; Williams, S. Jeffress; Thieler, E. Robert</p> <p>2004-01-01</p> <p>A coastal vulnerability index (CVI, http://pubs.usgs.gov/of/2004/1020/html/cvi.htm) was used to map relative vulnerability of the coast to future <span class="hlt">sea-level</span> rise within Assateague Island National Seashore (ASIS) in Maryland and Virginia. The CVI ranks the following in terms of their physical contribution to <span class="hlt">sea-level</span> rise-related coastal change: geomorphology, regional coastal slope, rate of relative <span class="hlt">sea-level</span> rise, shoreline change rates, mean tidal range and mean wave height. Rankings for each variable were combined and an index value calculated for 1-minute grid cells covering the park. The CVI highlights those regions where the physical effects of <span class="hlt">sea-level</span> rise might be the greatest. This approach combines the coastal system's susceptibility to change with its natural ability to adapt to changing environmental conditions, yielding a quantitative, although relative, <span class="hlt">measure</span> of the park's natural vulnerability to the effects of <span class="hlt">sea-level</span> rise. The CVI provides an objective technique for evaluation and long-term planning by scientists and park managers. Assateague Island consists of stable and washover dominated portions of barrier beach backed by wetland and marsh. The areas within Assateague that are likely to be most vulnerable to <span class="hlt">sea-level</span> rise are those with the highest occurrence of overwash and the highest rates of shoreline change.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013NatCC...3..477R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013NatCC...3..477R"><span>Assessment of groundwater inundation as a consequence of <span class="hlt">sea-level</span> rise</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rotzoll, Kolja; Fletcher, Charles H.</p> <p>2013-05-01</p> <p>Strong evidence on climate change underscores the need for actions to reduce the impacts of <span class="hlt">sea-level</span> rise. Global mean <span class="hlt">sea</span> <span class="hlt">level</span> may rise 0.18-0.48m by mid-century and 0.5-1.4m by the end of the century. Besides marine inundation, it is largely unrecognized that low-lying coastal areas may also be vulnerable to groundwater inundation, which is localized coastal-plain flooding due to a rise of the groundwater table with <span class="hlt">sea</span> <span class="hlt">level</span>. <span class="hlt">Measurements</span> of the coastal groundwater elevation and tidal influence in urban Honolulu, Hawaii, allow estimates of the mean water table, which was used to assess vulnerability to groundwater inundation from <span class="hlt">sea-level</span> rise. We find that 0.6m of potential <span class="hlt">sea-level</span> rise causes substantial flooding, and 1m <span class="hlt">sea-level</span> rise inundates 10% of a 1-km wide heavily urbanized coastal zone. The flooded area including groundwater inundation is more than twice the area of marine inundation alone. This has consequences for decision-makers, resource managers and urban planners, and may be applicable to many low-lying coastal areas, especially where groundwater withdrawal is not substantial.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2003/of03-439/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2003/of03-439/"><span>Coastal vulnerability assessment of Fire Island National Seashore to <span class="hlt">sea-level</span> rise</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Pendleton, Elizabeth A.; Williams, S. Jeffress; Thieler, E. Robert</p> <p>2004-01-01</p> <p>A coastal vulnerability index (CVI) was used to map the relative vulnerability of the coast to future <span class="hlt">sea-level</span> rise within Fire Island National Seashore (FIIS), New York. The CVI ranks the following in terms of their physical contribution to <span class="hlt">sea-level</span> rise-related coastal change: geomorphology, regional coastal slope, rate of relative <span class="hlt">sea-level</span> rise, shoreline change rates, mean tidal range and mean wave height. The rankings for each variable were combined and an index value calculated for 1-minute grid cells covering the park. The CVI highlights those regions where the physical effects of <span class="hlt">sea-level</span> rise might be the greatest. This approach combines the coastal system's susceptibility to change with its natural ability to adapt to changing environmental conditions, yielding a quantitative, although relative, <span class="hlt">measure</span> of the park's natural vulnerability to the effects of <span class="hlt">sea-level</span> rise. Fire Island consists of stable and washover dominated portions of barrier beach backed by lagoons, tidal wetlands and marsh. The areas most vulnerable to <span class="hlt">sea-level</span> rise are those with the highest historic occurrence of overwash and the highest rates of shoreline change. Implementation of large-scale beach nourishment and other coastal engineering alternatives being considered for Fire Island could alter the CVI computed here. The CVI provides an objective technique for evaluation and long-term planning by scientists and park managers.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1810735V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1810735V"><span>Uncertainties in <span class="hlt">sea</span> <span class="hlt">level</span> projections on twenty-year timescales</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vinogradova, Nadya; Davis, James; Landerer, Felix; Little, Chris</p> <p>2016-04-01</p> <p>Regional decadal changes in <span class="hlt">sea</span> <span class="hlt">level</span> are governed by various processes, including ocean dynamics, gravitational and solid earth responses, mass loss of continental ice, and other local coastal processes. In order to improve predictions and physical attribution in decadal <span class="hlt">sea</span> <span class="hlt">level</span> trends, the uncertainties of each processes must be reflected in the <span class="hlt">sea</span> <span class="hlt">level</span> calculations. Here we explore uncertainties in predictions of the decadal and bi-decadal changes in regional <span class="hlt">sea</span> <span class="hlt">level</span> induced by the changes in ocean dynamics and associated redistribution of heat and freshwater (often referred to as dynamic <span class="hlt">sea</span> <span class="hlt">level</span>). Such predictions are typically based on the solutions from coupled atmospheric and oceanic general circulation models, including a suite of climate models participating in phase 5 of the Coupled Model Intercompasion Project (CMIP5). Designed to simulate long-term ocean variability in response to warming climate due to increasing green-house gas concentration ("forced" response), CMIP5 are deficient in simulating variability at shorter time scales. In contrast, global observations of <span class="hlt">sea</span> <span class="hlt">level</span> are available during a relatively short time span (e.g., twenty-year altimetry records), and are dominated by an "unforced" variability that occurs freely (internally) within the climate system. This makes it challenging to examine how well observations compare with model simulations. Therefore, here we focus on patterns and spatial characteristics of projected twenty-year trends in dynamic <span class="hlt">sea</span> <span class="hlt">level</span>. Based on the ensemble of CMIP5 models, each comprising a 240-year run, we compute an envelope of twenty-year rates, and analyze the spread and spatial relationship among predicted rates. An ensemble root-mean-square average exhibits large-scale spatial patterns, with the largest uncertainties found over mid and high latitudes that could be attributed to the changes in wind patterns and buoyancy forcing. To understand and parameterize spatial characteristics of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24305147','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24305147"><span>Coastal flooding by tropical cyclones and <span class="hlt">sea-level</span> rise.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Woodruff, Jonathan D; Irish, Jennifer L; Camargo, Suzana J</p> <p>2013-12-05</p> <p>The future impacts of climate change on landfalling tropical cyclones are unclear. Regardless of this uncertainty, flooding by tropical cyclones will increase as a result of accelerated <span class="hlt">sea-level</span> rise. Under similar rates of rapid <span class="hlt">sea-level</span> rise during the early Holocene epoch most low-lying sedimentary coastlines were generally much less resilient to storm impacts. Society must learn to live with a rapidly evolving shoreline that is increasingly prone to flooding from tropical cyclones. These impacts can be mitigated partly with adaptive strategies, which include careful stewardship of sediments and reductions in human-induced land subsidence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUFM.H53C0483S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUFM.H53C0483S"><span>The Impact of <span class="hlt">Sea</span> <span class="hlt">Level</span> Rise on Florida's Everglades</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Senarath, S. U.</p> <p>2005-12-01</p> <p>Global warming and the resulting melting of polar ice sheets could increase global <span class="hlt">sea</span> <span class="hlt">levels</span> significantly. Some studies have predicted mean <span class="hlt">sea</span> <span class="hlt">level</span> increases in the order of six inches to one foot in the next 25 to 50 years. This could have severe irreversible impacts on low-lying areas of Florida's Everglades. The key objective of this study is to evaluate the effects of a one foot <span class="hlt">sea</span> <span class="hlt">level</span> rise on Cape Sable Seaside Sparrow (CSSS) nesting areas within the Everglades National Park (ENP). A regional-scale hydrologic model is used to assess the sensitivities of this <span class="hlt">sea-level</span> rise scenario. Florida's Everglades supports a unique ecosystem. At present, about 50 percent of this unique ecosystem has been lost due to urbanization and farming. Today, the water flow in the remnant Everglades is also regulated to meet a variety of competing environmental, water-supply and flood-control needs. A 30-year, eight billion dollar (1999 estimate) project has been initiated to improve Everglades' water flows. The expected benefits of this restoration project will be short-lived if the predicted <span class="hlt">sea</span> <span class="hlt">level</span> rise causes severe impacts on the environmentally sensitive areas of the Everglades. Florida's Everglades is home to many threatened and endangered species of wildlife. The Cape Sable Seaside Sparrow population in the ENP is one such species that is currently listed as endangered. Since these birds build their nests close to the ground surface (the base of the nest is approximately six inches from the ground surface), they are directly affected by any <span class="hlt">sea</span> <span class="hlt">level</span> induced ponding depth, frequency or duration change. Therefore, the CSSS population serves as a good indicator species for evaluating the negative impacts of <span class="hlt">sea</span> <span class="hlt">level</span> rise on the Everglades' ecosystem. The impact of <span class="hlt">sea</span> <span class="hlt">level</span> rise on the CSSS habitat is evaluated using the Regional Simulation Model (RSM) developed by the South Florida Water Management District. The RSM is an implicit, finite-volume, continuous</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1172858','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1172858"><span>Land-ice modeling for <span class="hlt">sea-level</span> prediction</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lipscomb, William H</p> <p>2010-06-11</p> <p>There has been major progress in ice sheet modeling since IPCC AR4. We will soon have efficient higherorder ice sheet models that can run at ",1 km resolution for entire ice sheets, either standalone or coupled to GeMs. These models should significantly reduce uncertainties in <span class="hlt">sea-level</span> predictions. However, the least certain and potentially greatest contributions to 21st century <span class="hlt">sea-level</span> rise may come from ice-ocean interactions, especially in West Antarctica. This is a coupled modeling problem that requires collaboration among ice, ocean and atmosphere modelers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SGeo...38....7A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SGeo...38....7A"><span>Satellite Altimetry-Based <span class="hlt">Sea</span> <span class="hlt">Level</span> at Global and Regional Scales</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ablain, M.; Legeais, J. F.; Prandi, P.; Marcos, M.; Fenoglio-Marc, L.; Dieng, H. B.; Benveniste, J.; Cazenave, A.</p> <p>2017-01-01</p> <p>Since the beginning of the 1990s, <span class="hlt">sea</span> <span class="hlt">level</span> is routinely <span class="hlt">measured</span> using high-precision satellite altimetry. Over the past 25 years, several groups worldwide involved in processing the satellite altimetry data regularly provide updates of <span class="hlt">sea</span> <span class="hlt">level</span> time series at global and regional scales. Here we present an ongoing effort supported by the European Space Agency (ESA) Climate Change Initiative Programme for improving the altimetry-based <span class="hlt">sea</span> <span class="hlt">level</span> products. Two main objectives characterize this enterprise: (1) to make use of ESA missions (ERS-1 and 2 and Envisat) in addition to the so-called `reference' missions like TOPEX/Poseidon and the Jason series in the computation of the <span class="hlt">sea</span> <span class="hlt">level</span> time series, and (2) to improve all processing steps in order to meet the Global Climate Observing System (GCOS) accuracy requirements defined for a set of 50 Essential Climate Variables, <span class="hlt">sea</span> <span class="hlt">level</span> being one of them. We show that improved geophysical corrections, dedicated processing algorithms, reduction of instrumental bias and drifts, and careful linkage between missions led to improved <span class="hlt">sea</span> <span class="hlt">level</span> products. Regarding the long-term trend, the new global mean <span class="hlt">sea</span> <span class="hlt">level</span> record accuracy now approaches the GCOS requirements (of 0.3 mm/year). Regional trend uncertainty has been reduced by a factor of 2, but orbital and wet tropospheric corrections errors still prevent fully reaching the GCOS accuracy requirement. Similarly at the interannual time scale, the global mean <span class="hlt">sea</span> <span class="hlt">level</span> still displays 2-4 mm errors that are not yet fully understood. The recent launch of new altimetry missions (Sentinel-3, Jason-3) and the inclusion of data from currently flying missions (e.g., CryoSat, SARAL/AltiKa) may provide further improvements to this important climate record.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=proton&pg=2&id=EJ843914','ERIC'); return false;" href="http://eric.ed.gov/?q=proton&pg=2&id=EJ843914"><span>Cosmic Rays with Portable Geiger Counters: From <span class="hlt">Sea</span> <span class="hlt">Level</span> to Airplane Cruise Altitudes</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Blanco, Francesco; La Rocca, Paola; Riggi, Francesco</p> <p>2009-01-01</p> <p>Cosmic ray count rates with a set of portable Geiger counters were <span class="hlt">measured</span> at different altitudes on the way to a mountain top and aboard an aircraft, between <span class="hlt">sea</span> <span class="hlt">level</span> and cruise altitude. Basic <span class="hlt">measurements</span> may constitute an educational activity even with high school teams. For the understanding of the results obtained, simulations of extensive…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19900040662&hterms=sea+level+rise&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsea%2Blevel%2Brise','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19900040662&hterms=sea+level+rise&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsea%2Blevel%2Brise"><span>Spectroscopic analysis of global tide gauge <span class="hlt">sea</span> <span class="hlt">level</span> data</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Trupin, A.; Wahr, J.</p> <p>1990-01-01</p> <p>Yearly and monthly global tide-gage <span class="hlt">sea-level</span> data are fitted to numerically generated tidal data in order to search for the 18.6-yr lunar nodal tide and 14-month pole tide. Both of these tides are clearly evident, with amplitudes and phases that are consistent with a global equilibrium response. The ocean's response to atmospheric pressure is studied with the least-squares fit technique. Consideration is given to the global rise in <span class="hlt">sea</span> <span class="hlt">level</span>, the effects of postglacial rebound, and the possible causes of the enhanced pole tides in the North <span class="hlt">Sea</span>, the Baltic <span class="hlt">Sea</span>, and the Gulf of Bothnia. The results support O'Connor's (1986) suggestion that the enhanced pole tide in these regions is due to meteorological forcing rather than a basin-scale resonance. Also, the global average of the tide-gage data show an increase in <span class="hlt">sea</span> <span class="hlt">level</span> over tha last 80 yr of between 1.1 and 1.9 mm/yr.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.1721S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.1721S"><span>Mean and extreme <span class="hlt">sea</span> <span class="hlt">level</span> changes in the southwestern Baltic <span class="hlt">Sea</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schmidt, Jessica; Patzke, Justus; Dangendorf, Sönke; Arns, Arne; Jensen, Jürgen; Fröhle, Peter</p> <p>2016-04-01</p> <p>In this contribution an overview over the BMBF project AMSeL_Ostsee (2015-2018) for the assessment of mean and extreme <span class="hlt">sea</span> <span class="hlt">level</span> changes over the past 150 years in the southwestern Baltic <span class="hlt">Sea</span> is presented. We compile several high resolution tide gauge records provided by the Water and Shipping Administration (WSV) along the German Baltic <span class="hlt">Sea</span> coastline and merge them in internationally available data bases (UHSLC, PSMSL, and data officially available at national authorities). In addition, we make efforts in digitizing historical records to expand the number of available data sets in this complex and vulnerable coastal region. To separate absolute from relative long-term changes in <span class="hlt">sea</span> <span class="hlt">level</span> the vertical land motion (VLM) at specific sites is assessed. Possible sources of VLM are independently assessed by using different state-of-the-art approaches, that is: Glacial Isostatic Adjustment (GIA) modelled by viscoelastic Earth models, GPS derived VLM, and the difference between tide gauge and nearby satellite altimetry. The VLM corrected tide gauge records are further assessed for linear and non-linear trends as well as possible acceleration/deceleration patterns by applying advanced time series models such as Singular System Analysis (SSA) combined with a Monte-Carlo-Autoregressive-Padding approach (Wahl et al., 2010). These trend assessments are applied to mean and extreme <span class="hlt">sea</span> <span class="hlt">levels</span> independently to prove whether observed changes in extremes are either due to an underlying trend on mean <span class="hlt">sea</span> <span class="hlt">levels</span> or changes in storminess. References: Wahl, T., Jensen, J., Frank, T. (2011): On analysing <span class="hlt">sea</span> <span class="hlt">level</span> rise in the German Bight since 1844, NHESS, 10, 171-179.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.G21B0820F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.G21B0820F"><span>Mass-induced [|#8#|]<span class="hlt">Sea</span> <span class="hlt">Level</span> Variations in the Red <span class="hlt">Sea</span> from Satellite Altimetry and GRACE</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Feng, W.; Lemoine, J.; Zhong, M.; Hsu, H.</p> <p>2011-12-01</p> <p>We have analyzed mass-induced <span class="hlt">sea</span> <span class="hlt">level</span> variations (SLVs) in the Red <span class="hlt">Sea</span> from steric-corrected altimetry and GRACE between January 2003 and December 2010. The steric component of SLVs in the Red <span class="hlt">Sea</span> calculated from climatological temperature and salinity data is relatively small and anti-phase with the mass-induced SLV. The total SLV in the Red <span class="hlt">Sea</span> is mainly driven by the mass-induced SLV, which increases in winter when the Red <span class="hlt">Sea</span> gains the water mass from the Gulf of Aden and vice versa in summer. Spatial and temporal patterns of mass-induced SLVs in the Red <span class="hlt">Sea</span> from steric-corrected altimetry agree very well with GRACE observations. Both of two independent observations show high annual amplitude in the central Red <span class="hlt">Sea</span> (>20cm). Total mass-induced SLVs in the Red <span class="hlt">Sea</span> from two independent observations have similar annual amplitude and phase. One main purpose of our work is to see whether GRGS's ten-day GRACE results can observe intra-seasonal mass change in the Red <span class="hlt">Sea</span>. The wavelet coherence analysis indicates that GRGS's results show the high correlation with the steric-corrected SLVs on intra-seasonal time scale. The agreement is excellent for all the time-span until 1/3 year period and is patchy between 1/3 and 1/16 year period. Furthermore, water flux estimates from current-meter arrays and moorings show mass gain in winter and mass loss in summer, which is also consistent with altimetry and GRACE.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080009450','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080009450"><span>Wireless Fluid <span class="hlt">Level</span> <span class="hlt">Measuring</span> System</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Taylor, Bryant D. (Inventor); Woodard, Stanley E. (Inventor)</p> <p>2007-01-01</p> <p>A <span class="hlt">level</span>-sensing probe positioned in a tank is divided into sections with each section including (i) a fluid-<span class="hlt">level</span> capacitive sensor disposed along the length thereof, (ii) an inductor electrically coupled to the capacitive sensor, (iii) a sensor antenna positioned for inductive coupling to the inductor, and (iv) an electrical conductor coupled to the sensor antenna. An electrically non-conductive housing accessible from a position outside of the tank houses antennas arrayed in a pattern. Each antenna is electrically coupled to the electrical conductor from a corresponding one of the sections. A magnetic field response recorder has a <span class="hlt">measurement</span> head with transceiving antennas arrayed therein to correspond to the pattern of the housing's antennas. When a <span class="hlt">measurement</span> is to be taken, the <span class="hlt">measurement</span> head is mechanically coupled to the housing so that each housing antenna is substantially aligned with a specific one of the transceiving antennas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012ERL.....7b1001R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012ERL.....7b1001R"><span><span class="hlt">Sea-level</span> rise: towards understanding local vulnerability</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rahmstorf, Stefan</p> <p>2012-06-01</p> <p>Projections of global <span class="hlt">sea-level</span> rise into the future have become more pessimistic over the past five years or so. A global rise by more than one metre by the year 2100 is now widely accepted as a serious possibility if greenhouse gas emissions continue unabated. That is witnessed by the scientific assessments that were made since the last IPCC report was published in 2007. The Delta Commission of the Dutch government projected up to 1.10 m as a 'high-end' scenario (Vellinga et al 2009). The Scientific Committee on Antarctic Research (SCAR) projected up to 1.40 m (Scientific Committee on Antarctic Research 2009), and the Arctic Monitoring and Assessment Programme (AMAP) gives a range of 0.90-1.60 m in its 2011 report (Arctic Monitoring and Assessment Programme 2011). And recently the US Army Corps of Engineers recommends using a 'low', an 'intermediate' and a 'high' scenario for global <span class="hlt">sea-level</span> rise when planning civil works programmes, with the high one corresponding to a 1.50 m rise by 2100 (US Army Corps of Engineers 2011). This more pessimistic view is based on a number of observations, most importantly perhaps the fact that <span class="hlt">sea</span> <span class="hlt">level</span> has been rising at least 50% faster in the past decades than projected by the IPCC (Rahmstorf et al 2007, IPCC 2007). Also, the rate of rise (averaged over two decades) has accelerated threefold, from around 1 mm yr-1 at the start of the 20th century to around 3 mm yr-1 over the past 20 years (Church and White 2006), and this rate increase closely correlates with global warming (Rahmstorf et al 2011). The IPCC projections, which assume almost no further acceleration in the 20th century, thus look less plausible. And finally the observed net mass loss of the two big continental ice sheets (Van den Broeke et al 2011) calls into question the assumption that ice accumulation in Antarctica would largely balance ice loss from Greenland in the course of further global warming (IPCC 2007). With such a serious <span class="hlt">sea-level</span> rise on the horizon</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5999325','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5999325"><span>Mid-Cretaceous Eustatic <span class="hlt">sea</span> <span class="hlt">level</span> fall: magnitude and timing in Gulf of Mexico</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Vierbuchen, R.C.; Oestmann, M.A.; Greenlee, S.M.</p> <p>1987-05-01</p> <p>The magnitude and timing of a mid-Cretaceous <span class="hlt">sea</span> <span class="hlt">level</span> fall have been documented on the margins of the Gulf of Mexico in east Texas. Analysis of seismic, log, and paleontologic data from east Texas demonstrates that a fall of 60 to 100 m occurred at the end of Washita (mid-Cenomanian) time. This <span class="hlt">sea</span> <span class="hlt">level</span> fall has been identified elsewhere on the shelves of the Gulf of Mexico and is proposed to have caused the mid-Cretaceous unconformity of the deep <span class="hlt">sea</span> and the termination of Washita carbonate deposition. They conclude that this <span class="hlt">sea</span> <span class="hlt">level</span> fall is of regional significance and eustatic origin. The magnitude and timing of the fall agree with those postulated by Vail and others, and Haq and others, who recognized a major <span class="hlt">sea</span> <span class="hlt">level</span> fall in mid-Cenomanian time. The magnitude of <span class="hlt">sea</span> <span class="hlt">level</span> fall is estimated from the difference in elevation between carbonate buildups on the Buda margin, which accumulated at or near <span class="hlt">sea</span> <span class="hlt">level</span>, and fluvial deposits in the lower Woodbine, which immediately overlie Buda carbonates and have been drilled up to 20 km basinward of the shelf margin. After constructing a datum along the preexisting Buda shelf, they <span class="hlt">measure</span> the thickness of sediment from this datum to the onlapping fluvial, lower Woodbine siliciclastics. This <span class="hlt">measurement</span> is then corrected for compaction, isostatic subsidence due to sediment loading, and thermotectonic subsidence. The result, 60 m, is considered a minimum estimate. A similar <span class="hlt">measurement</span> to the lowest seismically identified coastal onlap in the lower Woodbine yields an estimate of 100 m.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4245127','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4245127"><span>Long-Memory and the <span class="hlt">Sea</span> <span class="hlt">Level</span>-Temperature Relationship: A Fractional Cointegration Approach</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ventosa-Santaulària, Daniel; Heres, David R.; Martínez-Hernández, L. Catalina</p> <p>2014-01-01</p> <p>Through thermal expansion of oceans and melting of land-based ice, global warming is very likely contributing to the <span class="hlt">sea</span> <span class="hlt">level</span> rise observed during the 20th century. The amount by which further increases in global average temperature could affect <span class="hlt">sea</span> <span class="hlt">level</span> is only known with large uncertainties due to the limited capacity of physics-based models to predict <span class="hlt">sea</span> <span class="hlt">levels</span> from global surface temperatures. Semi-empirical approaches have been implemented to estimate the statistical relationship between these two variables providing an alternative <span class="hlt">measure</span> on which to base potentially disrupting impacts on coastal communities and ecosystems. However, only a few of these semi-empirical applications had addressed the spurious inference that is likely to be drawn when one nonstationary process is regressed on another. Furthermore, it has been shown that spurious effects are not eliminated by stationary processes when these possess strong long memory. Our results indicate that both global temperature and <span class="hlt">sea</span> <span class="hlt">level</span> indeed present the characteristics of long memory processes. Nevertheless, we find that these variables are fractionally cointegrated when <span class="hlt">sea</span>-ice extent is incorporated as an instrumental variable for temperature which in our estimations has a statistically significant positive impact on global <span class="hlt">sea</span> <span class="hlt">level</span>. PMID:25426638</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25426638','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25426638"><span>Long-memory and the <span class="hlt">sea</span> <span class="hlt">level</span>-temperature relationship: a fractional cointegration approach.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ventosa-Santaulària, Daniel; Heres, David R; Martínez-Hernández, L Catalina</p> <p>2014-01-01</p> <p>Through thermal expansion of oceans and melting of land-based ice, global warming is very likely contributing to the <span class="hlt">sea</span> <span class="hlt">level</span> rise observed during the 20th century. The amount by which further increases in global average temperature could affect <span class="hlt">sea</span> <span class="hlt">level</span> is only known with large uncertainties due to the limited capacity of physics-based models to predict <span class="hlt">sea</span> <span class="hlt">levels</span> from global surface temperatures. Semi-empirical approaches have been implemented to estimate the statistical relationship between these two variables providing an alternative <span class="hlt">measure</span> on which to base potentially disrupting impacts on coastal communities and ecosystems. However, only a few of these semi-empirical applications had addressed the spurious inference that is likely to be drawn when one nonstationary process is regressed on another. Furthermore, it has been shown that spurious effects are not eliminated by stationary processes when these possess strong long memory. Our results indicate that both global temperature and <span class="hlt">sea</span> <span class="hlt">level</span> indeed present the characteristics of long memory processes. Nevertheless, we find that these variables are fractionally cointegrated when <span class="hlt">sea</span>-ice extent is incorporated as an instrumental variable for temperature which in our estimations has a statistically significant positive impact on global <span class="hlt">sea</span> <span class="hlt">level</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/50808','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/50808"><span>Global mean <span class="hlt">sea</span> <span class="hlt">level</span> variations from TOPEX/POSEIDON altimeter data</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Nerem, R.S.</p> <p>1995-05-05</p> <p>The TOPEX/POSEIDON satellite altimeter mission has <span class="hlt">measured</span> global mean <span class="hlt">sea</span> <span class="hlt">level</span> every 10 days over the last 2 years with a precision of 4 millimeters, which approaches the requirements for climate change research. The estimated rate of <span class="hlt">sea</span> <span class="hlt">level</span> change is +3.9 {+-} 0.8 millimeters per year. A substantial portion of this trend may represent a short-term variation unrelated to the long-term signal expected from global warming. For this reason, and because the long-term <span class="hlt">measurement</span> accuracy requires additional monitoring, a longer time series is necessary before climate change signals can be unequivocally detected. 37 refs., 1 fig.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17832385','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17832385"><span>Global Mean <span class="hlt">Sea</span> <span class="hlt">Level</span> Variations from TOPEX/POSEIDON Altimeter Data.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nerem, R S</p> <p>1995-05-05</p> <p>The TOPEX/POSEIDON satellite altimeter mission has <span class="hlt">measured</span> global mean <span class="hlt">sea</span> <span class="hlt">level</span> every 10 days over the last 2 years with a precision of 4 millimeters, which approaches the requirements for climate change research. The estimated rate of <span class="hlt">sea</span> <span class="hlt">level</span> change is +3.9 +/- 0.8 millimeters per year. A substantial portion of this trend may represent a short-term variation unrelated to the long-term signal expected from global warming. For this reason, and because the long-term <span class="hlt">measurement</span> accuracy requires additional monitoring, a longer time series is necessary before climate change signals can be unequivocally detected.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AtmRe..93..700K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AtmRe..93..700K"><span>Ship <span class="hlt">measurements</span> of submicron aerosol size distributions over the Yellow <span class="hlt">Sea</span> and the East China <span class="hlt">Sea</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kim, Jong Hwan; Yum, Seong Soo; Lee, Young-Gon; Choi, Byoung-Cheol</p> <p>2009-08-01</p> <p>During the spring of 2005, the total particle concentrations and the submicron aerosol size distributions were <span class="hlt">measured</span> on board the research vessel over the south <span class="hlt">sea</span> of Korea and the Korean sector of the Yellow <span class="hlt">Sea</span>. Similar <span class="hlt">measurements</span> were made over the East China <span class="hlt">Sea</span> in autumn 2005. The aerosol properties varied dynamically according to the meteorological conditions, the proximity to the land masses and the air mass back trajectories. The average total particle concentration was the lowest over the East China <span class="hlt">Sea</span>, 4335 ± 2736 cm - 3, but the instantaneous minimum, 837 cm - 3, for the entire ship <span class="hlt">measurement</span> was recorded during the Yellow <span class="hlt">Sea</span> cruise. There was also a long (more than 6 h) stretch of low total particle concentrations that fell as low as 1025 cm - 3 during the East China <span class="hlt">Sea</span> cruise when the ship was the farthest from the shores and the air mass back trajectories resided long hours over the <span class="hlt">sea</span>. These observations lead to the suggestion of ~ 1000 cm - 3 as the background total particle concentration over the marine boundary layer in the studied region of the Yellow <span class="hlt">Sea</span> and the East China <span class="hlt">Sea</span>, implying significant anthropogenic influence even for the background value. In the mean time, average aerosol size distributions were unimodal and the mode diameter ranged between 52 and 86 nm, excluding the fog periods, which suggests that the aerosols <span class="hlt">measured</span> in this study experienced relatively less aging processes within the marine boundary layer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFMNH13B..04N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFMNH13B..04N"><span>Simulations of <span class="hlt">Sea</span> <span class="hlt">Level</span> Rise Effects on Complex Coastal Systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Niedoroda, A. W.; Ye, M.; Saha, B.; Donoghue, J. F.; Reed, C. W.</p> <p>2009-12-01</p> <p>It is now established that complex coastal systems with elements such as beaches, inlets, bays, and rivers adjust their morphologies according to time-varying balances in between the processes that control the exchange of sediment. Accelerated <span class="hlt">sea</span> <span class="hlt">level</span> rise introduces a major perturbation into the sediment-sharing systems. A modeling framework based on a new SL-PR model which is an advanced version of the aggregate-scale CST Model and the event-scale CMS-2D and CMS-Wave combination have been used to simulate the recent evolution of a portion of the Florida panhandle coast. This combination of models provides a method to evaluate coefficients in the aggregate-scale model that were previously treated as fitted parameters. That is, by carrying out simulations of a complex coastal system with runs of the event-scale model representing more than a year it is now possible to directly relate the coefficients in the large-scale SL-PR model to <span class="hlt">measureable</span> physical parameters in the current and wave fields. This cross-scale modeling procedure has been used to simulate the shoreline evolution at the Santa Rosa Island, a long barrier which houses significant military infrastructure at the north Gulf Coast. The model has been used to simulate 137 years of <span class="hlt">measured</span> shoreline change and to extend these to predictions of future rates of shoreline migration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21170501','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21170501"><span>The body weight loss during acute exposure to high-altitude hypoxia in <span class="hlt">sea</span> <span class="hlt">level</span> residents.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ge, Ri-Li; Wood, Helen; Yang, Hui-Huang; Liu, Yi-Ning; Wang, Xiu-Juan; Babb, Tony</p> <p>2010-12-25</p> <p>Weight loss is frequently observed after acute exposure to high altitude. However, the magnitude and rate of weight loss during acute exposure to high altitude has not been clarified in a controlled prospective study. The present study was performed to evaluate weight loss at high altitude. A group of 120 male subjects [aged (32±6) years] who worked on the construction of the Golmud-Lhasa Railway at Kunlun Mountain (altitude of 4 678 m) served as volunteer subjects for this study. Eighty-five workers normally resided at <span class="hlt">sea</span> <span class="hlt">level</span> (<span class="hlt">sea</span> <span class="hlt">level</span> group) and 35 normally resided at an altitude of 2 200 m (moderate altitude group). Body weight, body mass index (BMI), and waist circumference were <span class="hlt">measured</span> in all subjects after a 7-day stay at Golmud (altitude of 2 800 m, baseline <span class="hlt">measurements</span>). <span class="hlt">Measurements</span> were repeated after 33-day working on Kunlun Mountain. In order to examine the daily rate of weight loss at high altitude, body weight was <span class="hlt">measured</span> in 20 subjects from the <span class="hlt">sea</span> <span class="hlt">level</span> group (<span class="hlt">sea</span> <span class="hlt">level</span> subset group) each morning before breakfast for 33 d at Kunlun Mountain. According to guidelines established by the Lake Louise acute mountain sickness (AMS) consensus report, each subject completed an AMS self-report questionnaire two days after arriving at Kunlun Mountain. After 33-day stay at an altitude of 4 678 m, the average weight loss for the <span class="hlt">sea</span> <span class="hlt">level</span> group was 10.4% (range 6.5% to 29%), while the average for the moderate altitude group was 2.2% (-2% to 9.1%). The degree of weight loss (Δ weight loss) after a 33-day stay at an altitude of 4 678 m was significantly correlated with baseline body weight in the <span class="hlt">sea</span> <span class="hlt">level</span> group (r=0.677, P<0.01), while the correlation was absent in the moderate altitude group (r=0.296, P>0.05). In the <span class="hlt">sea</span> <span class="hlt">level</span> subset group, a significant weight loss was observed within 20 d, but the weight remained stable thereafter. AMS-score at high altitude was significantly higher in the <span class="hlt">sea</span> <span class="hlt">level</span> group (4.69±2.48) than that in the moderate</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..1413767Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..1413767Y"><span>Preparing Coastal Parks for Future <span class="hlt">Sea</span> <span class="hlt">Level</span> Rise</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Young, R.; Peek, K.</p> <p>2012-04-01</p> <p>The United States National Park Service (NPS) manages significant stretches of shoreline along the U.S. Atlantic, Pacific, and Gulf Coasts that are vulnerable to long-term <span class="hlt">sea</span> <span class="hlt">level</span> rise, shoreline erosion, and storm impacts. These parks have a wide variety of missions— protecting some of the nation's most important natural and cultural resources. The parks must also provide visitor access and education requiring infrastructure such as roads, visitor centers, trails, and buildings for facilities management. Planning for the likely impacts from <span class="hlt">sea</span> <span class="hlt">level</span> rise to both resources and infrastructure is a complex balancing act. Using coastal engineering to protect cultural resources or infrastructure may harm natural resources. At the same time, there are clearly some cultural and historical resources that are so critical that they must be protected. In an attempt to begin to attack this dilemma, the NPS Climate Change Response Program has initiated a <span class="hlt">sea</span> <span class="hlt">level</span> rise adaptation study that will provide a first-order tally of the park assets at risk to <span class="hlt">sea</span> <span class="hlt">level</span> rise and to begin to develop a plan for prioritizing those assets that must be protected, those that can be moved or abandoned, and an examination of how best to approach this without harming critical natural resources. This presentation will discuss the preliminary results of this effort along with several relevant case studies.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5112891','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5112891"><span>Fluctuating Mesozoic and Cenozoic <span class="hlt">sea</span> <span class="hlt">levels</span> and implications for stratigraphy</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Haq, B.U. )</p> <p>1988-12-01</p> <p>Sequence stratigraphy encompasses depositional models of genetically related packages of sediments deposited during various phases of cycle of <span class="hlt">sea</span> <span class="hlt">level</span> change, i.e., from a lowstand to highstand to the subsequent lowstand. The application of these models to marine outcrops around the world and to subsurface data led to the construction of Mesozoic-Cenozoic <span class="hlt">sea</span> <span class="hlt">level</span> curves with greater event resolution than the earlier curves based on seismic data alone. Construction of these better resolution curves begins with an outline of the principles of sequence-stratigraphic analysis and the reconstruction of the history of <span class="hlt">sea</span> <span class="hlt">level</span> change from outcrop and subsurface data for the past 250 Ma. Examples of marine sections from North America, Europe, and Asia can be used to illustrate sequence analysis of outcrop data and the integration of chronostratigraphy with <span class="hlt">sea</span> <span class="hlt">level</span> history. Also important are the implications of sequence-stratigraphic methodology and the new cycle charts to various disciplines of stratigraphy, environmental reconstruction, and basin analysis. The relationship of unconformities along the continental margins to hiatuses and dissolution surfaces in the deep basins must also be explored, as well as the relevance of sequence-stratigraphic methodology to biofacies and source rock prediction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.5412S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.5412S"><span>Anomalous secular <span class="hlt">sea-level</span> acceleration in the Baltic <span class="hlt">Sea</span> caused by glacial isostatic adjustment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Spada, Giorgio; Galassi, Gaia; Olivieri, Marco</p> <p>2014-05-01</p> <p>Observations from the global array of tide gauges show that global <span class="hlt">sea-level</span> has been rising at an average rate of 1.5-2 mm/yr during the last ˜ 150 years (Spada & Galassi, 2012). Although a global <span class="hlt">sea-level</span> acceleration was initially ruled out, subsequent studies have coherently proposed values of ˜1 mm/year/century (Olivieri & Spada, 2012). More complex non-linear trends and abrupt <span class="hlt">sea-level</span> variations have now also been recognized. Globally, they could manifest a regime shift between the late Holocene and the current rhythms of <span class="hlt">sea-level</span> rise, while locally they result from ocean circulation anomalies, steric effects and wind stress (Bromirski et al. 2011). Although isostatic readjustment affects the local rates of secular <span class="hlt">sea-level</span> change, a possible impact on regional acceleration have been so far discounted (Woodworth et al., 2009) since the process evolves on a millennium scale. Here we report a previously unnoticed anomaly in the long-term <span class="hlt">sea-level</span> acceleration of the Baltic <span class="hlt">Sea</span> tide gauge records, and we explain it by the classical post-glacial rebound theory and numerical modeling of glacial isostasy. Contrary to previous assumptions, our findings demonstrate that isostatic compensation plays a role in the regional secular <span class="hlt">sea-level</span> acceleration. In response to glacial isostatic adjustment (GIA), tide gauge records located along the coasts of the Baltic <span class="hlt">Sea</span> exhibit a small - but significant - long-term <span class="hlt">sea-level</span> acceleration in excess to those in the far field of previously glaciated regions. The sign and the amplitude of the anomaly is consistent with the post-glacial rebound theory and with realistic numerical predictions of GIA models routinely employed to decontaminate the tide gauges observations from the GIA effects (Peltier, 2004). Model computations predict the existence of anomalies of similar amplitude in other regions of the globe where GIA is still particularly vigorous at present, but no long-term instrumental observations are available to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26587277','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26587277"><span>Keep up or drown: adjustment of western Pacific coral reefs to <span class="hlt">sea-level</span> rise in the 21st century.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>van Woesik, R; Golbuu, Y; Roff, G</p> <p>2015-07-01</p> <p>Since the Mid-Holocene, some 5000 years ago, coral reefs in the Pacific Ocean have been vertically constrained by <span class="hlt">sea</span> <span class="hlt">level</span>. Contemporary <span class="hlt">sea-level</span> rise is releasing these constraints, providing accommodation space for vertical reef expansion. Here, we show that Porites microatolls, from reef-flat environments in Palau (western Pacific Ocean), are 'keeping up' with contemporary <span class="hlt">sea-level</span> rise. <span class="hlt">Measurements</span> of 570 reef-flat Porites microatolls at 10 locations around Palau revealed recent vertical skeletal extension (78±13 mm) over the last 6-8 years, which is consistent with the timing of the recent increase in <span class="hlt">sea</span> <span class="hlt">level</span>. We modelled whether microatoll growth rates will potentially 'keep up' with predicted <span class="hlt">sea-level</span> rise in the near future, based upon average growth, and assuming a decline in growth for every 1°C increase in temperature. We then compared these estimated extension rates with rates of <span class="hlt">sea-level</span> rise under four Representative Concentration Pathways (RCPs). Our model suggests that under low-mid RCP scenarios, reef-coral growth will keep up with <span class="hlt">sea-level</span> rise, but if greenhouse gas concentrations exceed 670 ppm atmospheric CO2 <span class="hlt">levels</span> and with +2.2°C <span class="hlt">sea</span>-surface temperature by 2100 (RCP 6.0 W m(-2)), our predictions indicate that Porites microatolls will be unable to keep up with projected rates of <span class="hlt">sea-level</span> rise in the twenty-first century.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.4447J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.4447J"><span>Revisiting <span class="hlt">sea</span> <span class="hlt">level</span> changes in the North <span class="hlt">Sea</span> during the Anthropocene</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jensen, Jürgen; Dangendorf, Sönke; Wahl, Thomas; Niehüser, Sebastian</p> <p>2016-04-01</p> <p>The North <span class="hlt">Sea</span> is one of the best instrumented ocean basins in the world. Here we revisit <span class="hlt">sea</span> <span class="hlt">level</span> changes in the North <span class="hlt">Sea</span> region from tide gauges, satellite altimetry, hydrographic profiles and ocean reanalysis data from the beginning of the 19th century to present. This includes an overview of the <span class="hlt">sea</span> <span class="hlt">level</span> chapter of the North <span class="hlt">Sea</span> Climate Change Assessment (NOSCCA) complemented by results from more recent investigations. The estimates of long-term changes from tide gauge records are significantly affected by vertical land motion (VLM), which is related to both the large-scale viscoelastic response of the solid earth to ice melting since the last deglaciation and local effects. Removing VLM (estimated from various data sources such as GPS, tide gauge minus altimetry and GIA) significantly reduces the spatial variability of long-term trends in the basin. VLM corrected tide gauge records suggest a transition from relatively moderate changes in the 19th century towards modern trends of roughly 1.5 mm/yr during the 20th century. Superimposed on the long-term changes there is a considerable inter-annual to multi-decadal variability. On inter-annual timescales this variability mainly reflects the barotropic response of the ocean to atmospheric forcing with the inverted barometer effect dominating along the UK and Norwegian coastlines and wind forcing controlling the southeastern part of the basin. The decadal variability is mostly remotely forced and dynamically linked to the North Atlantic via boundary waves in response to long-shore winds along the continental slope. These findings give valuable information about the required horizontal resolution of ocean models and the necessary boundary conditions and are therefore important for the dynamical downscaling of <span class="hlt">sea</span> <span class="hlt">level</span> projections for the North <span class="hlt">Sea</span> coastlines.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70186676','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70186676"><span><span class="hlt">Sea</span>-cave temperature <span class="hlt">measurements</span> and amino acid geochronology of British Late Pleistocene <span class="hlt">Sea</span> stands</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Hollin, John T.; Smith, Franklin L.; Renouf, John T.; Jenkins, D. Graham</p> <p>1993-01-01</p> <p>‘Calibrating’ amino acid ratios with uranium-series dates requires an accurate knowledge of current mean annual temperatures (CMATs) over the region studied. To <span class="hlt">measure</span> these, test-tube sized ‘diffusion sensors’ were emplaced for 1 year (in 1984, 1985 and 1986), both outside and inside Minchin Hole <span class="hlt">sea</span>-cave in South Wales and Belle Hougue <span class="hlt">sea</span>-cave in Jersey, both of which have yielded Oxygen Isotope Substage 5e uranium-series ages on speleothems. Our outside temperatures agreed with meteorological ones. Our inside temperatures were over 1°C lower. To allow for this, a mean of ‘empirical’, ‘linear’ and ‘parabolic’ epimerisation calculations suggests that ratios from molluscs inside the caves should be multiplied by over 1.1 for comparison with outside ratios. This raises Bowen et al.'s ‘Pennard’ stage ratios from inside Minchin (and Bacon) Hole up towards the ‘Unnamed’ stage ratios outside, and suggests that the Unnamed sites are also from Oxygen Isotope Substage 5e, as proposed by Proctor and Smart. The same conclusion is reached more strongly by comparisons with the ratios and temperatures inside Belle Hougue to the south, and at Eemian (assumed 5e) sites in The Netherlands, Germany and Denmark to the east. The Pennard ratios from outside sites may provide further evidence for global <span class="hlt">sea</span> stands close to the present <span class="hlt">level</span> later in Oxygen Isotope Stage 5.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010OcDyn..60..883M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010OcDyn..60..883M"><span>Variability in Solomon <span class="hlt">Sea</span> circulation derived from altimeter <span class="hlt">sea</span> <span class="hlt">level</span> data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Melet, Angélique; Gourdeau, Lionel; Verron, Jacques</p> <p>2010-08-01</p> <p>The Solomon <span class="hlt">Sea</span> is a key region in the Pacific Ocean where equatorial and subtropical circulations are connected. The region exhibits the highest <span class="hlt">levels</span> in <span class="hlt">sea</span> <span class="hlt">level</span> variability in the entire south tropical Pacific Ocean. Altimeter data was utilized to explore <span class="hlt">sea</span> <span class="hlt">level</span> and western boundary currents in this poorly understood portion of the ocean. Since the geography of the region is extremely intricate, with numerous islands and complex bathymetry, specifically reprocessed along-track data in addition to standard gridded data were utilized in this study. <span class="hlt">Sea</span> <span class="hlt">level</span> anomalies (SLA) in the Solomon <span class="hlt">Sea</span> principally evolve at seasonal and interannual time scales. The annual cycle is phased by Rossby waves arriving in the Solomon Strait, whereas the interannual signature corresponds to the basin-scale ENSO mode. The highest SLA variability are concentrated in the eastern Solomon <span class="hlt">Sea</span>, particularly at the mouth of the Solomon Strait, where they are associated with a high eddy kinetic energy signal that was particularly active during the phase transition during the 1997-1998 ENSO event. Track data appear especially helpful for documenting the fine structure of surface coastal currents. The annual variability of the boundary currents that emerged from altimetry compared quite well with the variability seen at the thermocline <span class="hlt">level</span>, as based on numerical simulations. At interannual time scales, western boundary current transport anomalies counterbalance changes in western equatorial Pacific warm water volume, confirming the phasing of South Pacific western boundary currents to ENSO. Altimetry appears to be a valuable source of information for variability in low latitude western boundary currents and their associated transport in the South Pacific.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JPRS...85...13S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JPRS...85...13S"><span>Improving MODIS <span class="hlt">sea</span> ice detectability using gray <span class="hlt">level</span> co-occurrence matrix texture analysis method: A case study in the Bohai <span class="hlt">Sea</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Su, Hua; Wang, Yunpeng; Xiao, Jie; Li, Lili</p> <p>2013-11-01</p> <p>An effective methodology for Bohai <span class="hlt">Sea</span> ice detection based on gray <span class="hlt">level</span> co-occurrence matrix (GLCM) texture analysis is proposed using MODIS 250 m imagery. The method determines texture <span class="hlt">measures</span> for <span class="hlt">sea</span> ice extraction by analyzing the discrepancy of textural features between <span class="hlt">sea</span> ice and <span class="hlt">sea</span> water. <span class="hlt">Sea</span> ice extent and outer edge are recognized accurately by texture segmentation owing to significant differences in texture statistical features between ice and water. The texture analysis method can properly eliminate perturbations on <span class="hlt">sea</span> ice extraction due to suspended sediment. It effectively solves the problem of spectral confusion and <span class="hlt">sea</span> ice misassignment in the conventional gray-threshold segmentation and ratio-threshold segmentation methods. The method eliminates the need for threshold range setting for <span class="hlt">sea</span> ice segmentation. Taking the Bohai <span class="hlt">Sea</span> as an example, the results of the proposed method are validated using co-temporal HJ1B-CCD 30 m imagery by visual interpretation, and the accuracy of the method are evaluated using confusion matrix. The results show that the proposed method is superior and more reliable for <span class="hlt">sea</span> ice detection compared to conventional methods, providing an ideal tool for precise <span class="hlt">sea</span> ice extraction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.G31A0911V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.G31A0911V"><span><span class="hlt">Sea</span> <span class="hlt">Level</span> Variation at the North Atlantic Ocean from Altimetry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vigo, I.; Sanchez-Reales, J. M.; Belda, S.</p> <p>2012-12-01</p> <p>About twenty years of multi-satellite radar altimeter data are analyzed to investigate the <span class="hlt">sea-level</span> variation (SLV) of the North Atlantic Ocean. In particular seasonal variations and inter-seasonal trends are studied. <span class="hlt">Sea</span> surface temperature and ice mass lost variations at Greenland are investigated as potential contributors of SLV in the case. It was found a quadratic acceleration term to be significant at some areas mainly located at the sub-polar gyre region. Results are consistent with changes in temperature data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.G21B0452H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.G21B0452H"><span>Mid- to Late Holocene <span class="hlt">Sea-Level</span> Record in French Polynesia, South-Central Pacific</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hallmann, N.; Camoin, G.; Vella, C.; Eisenhauer, A.; Samankassou, E.; Botella, A.; Milne, G. A.; Fietzke, J.; Dussouillez, P.; Plaine, J.</p> <p>2014-12-01</p> <p>The Mid- to Late Holocene provides the opportunity to study the coastal response to <span class="hlt">sea-level</span> change that has a similar amplitude (i.e., a few decimetres up to 1 m) to the <span class="hlt">sea-level</span> rise that is likely to occur before the end of the current century. Furthermore, this time period provides an important baseline of natural climate variability prior to the industrial revolution. This study aims to reconstruct Mid- to Late Holocene relative <span class="hlt">sea-level</span> change in French Polynesia by examining coral reef records from ten islands, which represent ideal settings for accurate <span class="hlt">sea-level</span> change studies because: 1) they can be regarded as tectonically stable during the relevant period (slow subsidence), 2) they are located far from former ice sheets ('far-field'), 3) they are characterized by a low tidal amplitude, and 4) they cover a wide range of latitudes which produces significantly improved constraints on GIA (Glacial Isostatic Adjustment) model parameters. The accurate reconstruction of <span class="hlt">sea-level</span> change relies on absolute U/Th dating of in situ coral colonies and their accurate positioning via GPS RTK (Real Time Kinematic) <span class="hlt">measurements</span> with a vertical and horizontal precision of ± 2.5 cm and ~1 cm, respectively. We focus mainly on the analysis of coral microatolls, which are sensitive low-tide recorders, as their vertical accretion is limited by the water <span class="hlt">level</span>. Their growth patterns allow the reconstruction of low-amplitude and high-frequency <span class="hlt">sea-level</span> changes on centennial to sub-decadal time scales. A <span class="hlt">sea-level</span> rise of less than ~1 m is documented between 6 and 3-3.5 ka, and is followed by a gradual fall in <span class="hlt">sea</span> <span class="hlt">level</span> that started around 2 ka and persisted until the past few centuries. The reconstructed <span class="hlt">sea-level</span> curve therefore extends the Tahiti <span class="hlt">sea-level</span> curve [Deschamps et al., 2012, Nature, 483, 559-564], and is in good agreement with a geophysical model tuned to fit far-field deglacial records [Bassett et al., 2005, Science, 309, 925-928].</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6577148','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6577148"><span><span class="hlt">Sea</span> <span class="hlt">level</span> during the Phanerozoic - what causes the fluctuations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Harrison, C.G.A.</p> <p>1985-01-01</p> <p>All possible causes of <span class="hlt">sea</span> <span class="hlt">level</span> change have been analyzed in order to explain the fall of <span class="hlt">sea</span> <span class="hlt">level</span> since the Cretaceous. The most important effect is the decrease in volume of the ridge crests due to an overall decrease in the rate of spreading since the Cretaceous. Other factors in order of decreasing importance are the reduction of the thermal bulge which accompanied the episode of Pacific volcanism between 110 and 70 my bp, the production of continental ice, the effect of the collision of India with Asia, and cooling of the ocean water. Sedimentation variation in the deep ocean has the effect of raising <span class="hlt">sea</span> <span class="hlt">level</span> a modest amount. The net variation in <span class="hlt">sea</span> <span class="hlt">level</span> during the past 80 million years has been a reduction by about 280 m after having allowed for isostatic adjustment of the ocean floor. This is considerably larger, than <span class="hlt">sea</span> <span class="hlt">level</span> calculated from the amount of continental flooding, and it is proposed that the discrepancy is due to a change in the continental hypsographic curve following the breakup of Pangea. This hypothesis is born out by studies of flooding during the Phanerozoic which reveal that flooding was very low at the beginning of the Mesozoic during a time of continental agglomeration, and high during much of the Paleozoic, which was a time of continental separation. In the Cambrian there is evidence for an increase in flooding with time, and at the beginning of the Cambrian flooding was not much greater than at the beginning of the Mesozoic, suggesting that it marked a time just subsequent to the break up of a super continent.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70024231','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70024231"><span>Responses of coastal wetlands to rising <span class="hlt">sea</span> <span class="hlt">level</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Morris, J.T.; Sundareshwar, P.V.; Nietch, C.T.; Kjerfve, B.; Cahoon, D.R.</p> <p>2002-01-01</p> <p>Salt marsh ecosystems are maintained by the dominant macrophytes that regulate the elevation of their habitat within a narrow portion of the intertidal zone by accumulating organic matter and trapping inorganic sediment. The long-term stability of these ecosystems is explained by interactions among <span class="hlt">sea</span> <span class="hlt">level</span>, land elevation, primary production, and sediment accretion that regulate the elevation of the sediment surface toward an equilibrium with mean <span class="hlt">sea</span> <span class="hlt">level</span>. We show here in a salt marsh that this equilibrium is adjusted upward by increased production of the salt marsh macrophyte Spartina alterniflora and downward by an increasing rate of relative <span class="hlt">sea-level</span> rise (RSLR). Adjustments in marsh surface elevation are slow in comparison to interannual anomalies and long-period cycles of <span class="hlt">sea</span> <span class="hlt">level</span>, and this lag in sediment elevation results in significant variation in annual primary productivity. We describe a theoretical model that predicts that the system will be stable against changes in relative mean <span class="hlt">sea</span> <span class="hlt">level</span> when surface elevation is greater than what is optimal for primary production. When surface elevation is less than optimal, the system will be unstable. The model predicts that there is an optimal rate of RSLR at which the equilibrium elevation and depth of tidal flooding will be optimal for plant growth. However, the optimal rate of RSLR also represents an upper limit because at higher rates of RSLR the plant community cannot sustain an elevation that is within its range of tolerance. For estuaries with high sediment loading, such as those on the southeast coast of the United States, the limiting rate of RSLR was predicted to be at most 1.2 cm/yr, which is 3.5 times greater than the current, long-term rate of RSLR.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.U22A..03C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.U22A..03C"><span>Understanding and projecting <span class="hlt">sea</span> <span class="hlt">level</span> change: improvements and uncertainties (Invited)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Church, J. A.; Clark, P. U.; Cazenave, A. A.; Gregory, J. M.; Jevrejeva, S.; Merrifield, M. A.; Milne, G. A.; Nerem, R.; Payne, A. J.; Pfeffer, W. T.; Stammer, D.; Levermann, A.; Nunn, P.; Unnikrishnan, A. S.</p> <p>2013-12-01</p> <p>The rate of global mean <span class="hlt">sea</span> <span class="hlt">level</span> rise (GMSLR) has accelerated during the last two centuries, from a rate of order tenths of mm yr-1 during the late Holocene, to about 1.7 mm yr-1 since 1901. Ocean thermal expansion and glacier melting were the dominant contributors to 20th century GMSLR, with relatively small contributions from the Greenland and Antarctic ice sheets. Process-based models suggest that the larger rate of rise since 1990 results from increased radiative forcing (both natural and anthropogenic) and increased ice-sheet outflow, induced by warming of the immediately adjacent ocean. Confidence in projections of global mean <span class="hlt">sea</span> <span class="hlt">level</span> rise has increased since the AR4 because of improved physical process-based understanding of observed <span class="hlt">sea</span> <span class="hlt">level</span> change, especially in recent decades, and the inclusion of future rapid ice-sheet dynamical changes, for which a quantitative assessment could not be made on the basis of scientific knowledge available at the time of the AR4. By 2100, the rate of GMSLR for a scenario of high emissions (RCP8.5) could approach the average rates that occurred during the last deglaciation, whereas for a strong emissions mitigation scenario (RCP2.6) it could stabilise at rates similar to those of the early 21st century. In either case, GMSLR will continue for many subsequent centuries. Although there has been much recent progress, projections of ice-sheet change are still uncertain, especially beyond 2100. Future <span class="hlt">sea</span> <span class="hlt">level</span> change will not be globally uniform, but models still exhibit substantial disagreement in projections of ice mass loss and ocean dynamics, which are the main influences on the pattern. Uncertainty in projections of future storminess is a further obstacle to confident projection of changes in <span class="hlt">sea</span> <span class="hlt">level</span> extremes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMOS33C1084P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMOS33C1084P"><span>Pacific <span class="hlt">Sea</span> <span class="hlt">Level</span> Rise Pattern and Global Warming Hiatus</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Peyser, C.; Yin, J.; Landerer, F. W.</p> <p>2014-12-01</p> <p>Two important topics in current climate research are the global warming hiatus and the seesaw pattern of <span class="hlt">sea</span> <span class="hlt">level</span> rise (SLR) in the Pacific Ocean. We use ocean temperature and <span class="hlt">sea-level</span> observations along with CMIP5 climate modelling data to investigate the relationship between the warming hiatus and <span class="hlt">sea-level</span> variability in the Pacific Ocean. We analyse ocean heat content (OHC) trend by basin and layer for the full record (1945-2012) as well as the hiatus period (1998-2012). The result confirms the importance of the Pacific for heat uptake during the hiatus. Notably, the subsurface layer of the Pacific shows significant increase in OHC during the hiatus and a strong east-west compensation. This is mainly responsible for and reflected by the seesaw pattern of the Pacific <span class="hlt">sea</span> <span class="hlt">level</span> through thermosteric effect. The control simulations from 38 CMIP5 models indicate that the seesaw pattern of SLR in the Pacific is mainly a feature of decadal to multidecadal variability. Most CMIP5 models can capture this variability, especially in the Pacific Decadal Oscillation region (poleward of 20°N). The CMIP5 control runs show that during periods of negative trends of global temperatures (analogous to hiatus decades in a warming world), <span class="hlt">sea</span> <span class="hlt">level</span> increases in the western Pacific and decreases in the eastern Pacific. The opposite is true during periods of positive temperature trend (accelerated warming). These results suggest that a possible flip of the Pacific SLR seesaw would imply a resumption of surface warming and a SLR acceleration along the U.S. West Coast.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMPP33C1251V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMPP33C1251V"><span>Evidence from the Seychelles of Last Interglacial <span class="hlt">Sea</span> <span class="hlt">Level</span> Oscillations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vyverberg, K.; Dutton, A.; Dechnik, B.; Webster, J.; Zwartz, D.</p> <p>2014-12-01</p> <p>Several studies indicate that <span class="hlt">sea</span> <span class="hlt">level</span> oscillated during Marine Isotope Stage (MIS) 5e, but the details of these scenarios, including the number of <span class="hlt">sea</span> <span class="hlt">level</span> oscillations, are still debated. We lack a detailed understanding of the sensitivity of the large polar ice sheets to changes in temperature that could result in eustatic <span class="hlt">sea</span> <span class="hlt">level</span> oscillations. Because the Seychelles are located far from the margins of the Last Glacial Maximum northern hemisphere ice sheets, they have not been subjected to glacial isostatic adjustment, and have been tectonically stable since the Last Interglacial period; therefore, they provide a robust record of eustatic <span class="hlt">sea</span> <span class="hlt">level</span> during MIS 5e. All of the outcrops we examined contain unconformities and/or sharp transitions between facies, though the nature of these boundaries varies between sites. In some outcrops we observed a hardground comprising fine-grained, mollusc-rich sediment layer between distinct generations of in situ coralgal framework. In one outcrop, this succession was observed twice, where two generations of reef growth were each capped by a strongly indurated fine-grained, mollusc-rich sediment layer. At the site with the greatest vertical extent of outcrop, there is a marked difference in the taxonomic composition of the coral community above and below an unconformable surface, but the indurated fine-grained, sediment layer observed elsewhere was absent. Most of the other outcrops we studied contained a common succession of facies from in situ reef units overlain by cemented coral rubble. In two dated outcrops, the age of corals above and below the rubble layer are the same age. The hardgrounds and rubble layers may represent ephemeral exposure of the reef units during two drops in <span class="hlt">sea</span> <span class="hlt">level</span>. The inference of multiple meter-scale oscillations during the MIS 5e highstand indicates a more dynamic cryosphere than the present interglacial, although the climatic threshold for more volatile polar ice sheets is not yet clear.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25629092','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25629092"><span>Probabilistic reanalysis of twentieth-century <span class="hlt">sea-level</span> rise.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hay, Carling C; Morrow, Eric; Kopp, Robert E; Mitrovica, Jerry X</p> <p>2015-01-22</p> <p>Estimating and accounting for twentieth-century global mean <span class="hlt">sea</span> <span class="hlt">level</span> (GMSL) rise is critical to characterizing current and future human-induced <span class="hlt">sea-level</span> change. Several previous analyses of tide gauge records--employing different methods to accommodate the spatial sparsity and temporal incompleteness of the data and to constrain the geometry of long-term <span class="hlt">sea-level</span> change--have concluded that GMSL rose over the twentieth century at a mean rate of 1.6 to 1.9 millimetres per year. Efforts to account for this rate by summing estimates of individual contributions from glacier and ice-sheet mass loss, ocean thermal expansion, and changes in land water storage fall significantly short in the period before 1990. The failure to close the budget of GMSL during this period has led to suggestions that several contributions may have been systematically underestimated. However, the extent to which the limitations of tide gauge analyses have affected estimates of the GMSL rate of change is unclear. Here we revisit estimates of twentieth-century GMSL rise using probabilistic techniques and find a rate of GMSL rise from 1901 to 1990 of 1.2 ± 0.2 millimetres per year (90% confidence interval). Based on individual contributions tabulated in the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, this estimate closes the twentieth-century <span class="hlt">sea-level</span> budget. Our analysis, which combines tide gauge records with physics-based and model-derived geometries of the various contributing signals, also indicates that GMSL rose at a rate of 3.0 ± 0.7 millimetres per year between 1993 and 2010, consistent with prior estimates from tide gauge records.The increase in rate relative to the 1901-90 trend is accordingly larger than previously thought; this revision may affect some projections of future <span class="hlt">sea-level</span> rise.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26062511','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26062511"><span>Bipolar seesaw control on last interglacial <span class="hlt">sea</span> <span class="hlt">level</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Marino, G; Rohling, E J; Rodríguez-Sanz, L; Grant, K M; Heslop, D; Roberts, A P; Stanford, J D; Yu, J</p> <p>2015-06-11</p> <p>Our current understanding of ocean-atmosphere-cryosphere interactions at ice-age terminations relies largely on assessments of the most recent (last) glacial-interglacial transition, Termination I (T-I). But the extent to which T-I is representative of previous terminations remains unclear. Testing the consistency of termination processes requires comparison of time series of critical climate parameters with detailed absolute and relative age control. However, such age control has been lacking for even the penultimate glacial termination (T-II), which culminated in a <span class="hlt">sea-level</span> highstand during the last interglacial period that was several metres above present. Here we show that Heinrich Stadial 11 (HS11), a prominent North Atlantic cold episode, occurred between 135 ± 1 and 130 ± 2 thousand years ago and was linked with rapid <span class="hlt">sea-level</span> rise during T-II. Our conclusions are based on new and existing data for T-II and the last interglacial that we collate onto a single, radiometrically constrained chronology. The HS11 cold episode punctuated T-II and coincided directly with a major deglacial meltwater pulse, which predominantly entered the North Atlantic Ocean and accounted for about 70 per cent of the glacial-interglacial <span class="hlt">sea-level</span> rise. We conclude that, possibly in response to stronger insolation and CO2 forcing earlier in T-II, the relationship between climate and ice-volume changes differed fundamentally from that of T-I. In T-I, the major <span class="hlt">sea-level</span> rise clearly post-dates Heinrich Stadial 1. We also find that HS11 coincided with sustained Antarctic warming, probably through a bipolar seesaw temperature response, and propose that this heat gain at high southern latitudes promoted Antarctic ice-sheet melting that fuelled the last interglacial <span class="hlt">sea-level</span> peak.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1615137S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1615137S"><span>Coastal Vulnerability Due to <span class="hlt">Sea-level</span> Rise Hazard in the Bangladesh Delta</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shum, Ck; Ballu, Valérie; Calmant, Stéphane; Duan, Jianbin; Guo, Junyi; Hossain, Fasial; Jenkins, Craig; Haque Khan, Zahirul; Kim, Jinwoo; Kuhn, Michael; Kusche, Jürgen; Papa, Fabrice; Tseng, Kuohsin; Wan, Junkun</p> <p>2014-05-01</p> <p>Approximately half of the world's population or 3.2 billion people lives within 200 km of coastlines and many of them in the world's deltaic plains. <span class="hlt">Sea-level</span> rise, widely recognized as one of consequences resulting from anthropogenic climate change, has induced substantial coastal vulnerability globally and in particular, in the deltaic regions, such as coastal Bangladesh, and Yangtze Delta. Bangladesh, a low-lying, one of the most densely populated countries in the world located at the Bay of Bengal, is prone to transboundary monsoonal flooding, potentially aggravated by more frequent and intensified cyclones resulting from anthropogenic climate change. <span class="hlt">Sea-level</span> rise, along with tectonic, sediment load and groundwater extraction induced land uplift/subsidence, have exacerbated Bangladesh's coastal vulnerability. Here we describe the physical science component of the integrated approach based on both physical and social sciences to address the adaption and potential mitigation of coastal Bangladesh vulnerability. The objective is to quantify the estimates of spatial varying <span class="hlt">sea-level</span> trend separating the vertical motion of the coastal regions using geodetic and remote-sensing <span class="hlt">measurements</span> (tide gauges, 1950-current; satellite altimetry, 1992-present, GRACE, 2003-present, Landsat/MODIS), reconstructed <span class="hlt">sea-level</span> trends (1950-current), and GPS and InSAR observed land subsidence. Our goal is to conduct physically based robust projection of relative <span class="hlt">sea-level</span> change at the end of the 21st century for the Bangladesh Delta to enable quantitative <span class="hlt">measures</span> of social science based adaption and possible mitigation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ISPAr62W1..237D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ISPAr62W1..237D"><span>The Impact of <span class="hlt">Sea</span> <span class="hlt">Level</span> Rise on Geodetic Vertical Datum of Peninsular Malaysia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Din, A. H. M.; Abazu, I. C.; Pa'suya, M. F.; Omar, K. M.; Hamid, A. I. A.</p> <p>2016-09-01</p> <p><span class="hlt">Sea</span> <span class="hlt">level</span> rise is rapidly turning into major issues among our community and all <span class="hlt">levels</span> of the government are working to develop responses to ensure these matters are given the uttermost attention in all facets of planning. It is more interesting to understand and investigate the present day <span class="hlt">sea</span> <span class="hlt">level</span> variation due its potential impact, particularly on our national geodetic vertical datum. To determine present day <span class="hlt">sea</span> <span class="hlt">level</span> variation, it is vital to consider both in-situ tide gauge and remote sensing <span class="hlt">measurements</span>. This study presents an effort to quantify the <span class="hlt">sea</span> <span class="hlt">level</span> rise rate and magnitude over Peninsular Malaysia using tide gauge and multi-mission satellite altimeter. The time periods taken for both techniques are 32 years (from 1984 to 2015) for tidal data and 23 years (from 1993 to 2015) for altimetry data. Subsequently, the impact of <span class="hlt">sea</span> <span class="hlt">level</span> rise on Peninsular Malaysia Geodetic Vertical Datum (PMGVD) is evaluated in this study. the difference between MSL computed from 10 years (1984 - 1993) and 32 years (1984 - 2015) tidal data at Port Kelang showed that the increment of <span class="hlt">sea</span> <span class="hlt">level</span> is about 27mm. The computed magnitude showed an estimate of the long-term effect a change in MSL has on the geodetic vertical datum of Port Kelang tide gauge station. This will help give a new insight on the establishment of national geodetic vertical datum based on mean <span class="hlt">sea</span> <span class="hlt">level</span> data. Besides, this information can be used for a wide variety of climatic applications to study environmental issues related to flood and global warming in Malaysia.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ClDy..tmp..367M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ClDy..tmp..367M"><span>Impact of accelerated future global mean <span class="hlt">sea</span> <span class="hlt">level</span> rise on hypoxia in the Baltic <span class="hlt">Sea</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Meier, H. E. M.; Höglund, A.; Eilola, K.; Almroth-Rosell, E.</p> <p>2016-08-01</p> <p>Expanding hypoxia is today a major threat for many coastal <span class="hlt">seas</span> around the world and disentangling its drivers is a large challenge for interdisciplinary research. Using a coupled physical-biogeochemical model we estimate the impact of past and accelerated future global mean <span class="hlt">sea</span> <span class="hlt">level</span> rise (GSLR) upon water exchange and oxygen conditions in a semi-enclosed, shallow <span class="hlt">sea</span>. As a study site, the Baltic <span class="hlt">Sea</span> was chosen that suffers today from eutrophication and from dead bottom zones due to (1) excessive nutrient loads from land, (2) limited water exchange with the world ocean and (3) perhaps other drivers like global warming. We show from model simulations for the period 1850-2008 that the impacts of past GSLR on the marine ecosystem were relatively small. If we assume for the end of the twenty-first century a GSLR of +0.5 m relative to today's mean <span class="hlt">sea</span> <span class="hlt">level</span>, the impact on the marine ecosystem may still be small. Such a GSLR corresponds approximately to the projected ensemble-mean value reported by the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. However, we conclude that GSLR should be considered in future high-end projections (>+1 m) for the Baltic <span class="hlt">Sea</span> and other coastal <span class="hlt">seas</span> with similar hydrographical conditions as in the Baltic because GSLR may lead to reinforced saltwater inflows causing higher salinity and increased vertical stratification compared to present-day conditions. Contrary to intuition, reinforced ventilation of the deep water does not lead to overall improved oxygen conditions but causes instead expanded dead bottom areas accompanied with increased internal phosphorus loads from the sediments and increased risk for cyanobacteria blooms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017E%26PSL.457..325W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017E%26PSL.457..325W"><span>Speleothem evidence for MIS 5c and 5a <span class="hlt">sea</span> <span class="hlt">level</span> above modern <span class="hlt">level</span> at Bermuda</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wainer, Karine A. I.; Rowe, Mark P.; Thomas, Alexander L.; Mason, Andrew J.; Williams, Bruce; Tamisiea, Mark E.; Williams, Felicity H.; Düsterhus, André; Henderson, Gideon M.</p> <p>2017-01-01</p> <p>The history of <span class="hlt">sea</span> <span class="hlt">level</span> in regions impacted by glacio-isostasy provides constraints on past ice-sheet distribution and on the characteristics of deformation of the planet in response to loading. The Western North Atlantic-Caribbean region, and Bermuda in particular, is strongly affected by the glacial forebulge that forms as a result of the Laurentide ice-sheet present during glacial periods. The timing of growth of speleothems, at elevations close to <span class="hlt">sea</span> <span class="hlt">level</span> can provide records of minimum relative <span class="hlt">sea</span> <span class="hlt">level</span> (RSL). In this study we used U-Th dating to precisely date growth periods of speleothems from Bermuda which were found close to modern-day <span class="hlt">sea</span> <span class="hlt">level</span>. Results suggest that RSL at this location was above modern during MIS5e, MIS5c and MIS5a. These data support controversial previous indications that Bermudian RSL was significantly higher than RSL at other locations during MIS 5c and MIS 5a. We confirm that it is possible to explain a wide range of MIS5c-a relative <span class="hlt">sea</span> <span class="hlt">levels</span> observed across the Western North Atlantic-Caribbean in glacial isostatic adjustment models, but only with a limited range of mantle deformation constants. This study demonstrates the particular power of Bermuda as a gauge for response of the forebulge to glacial loading, and demonstrates the potential for highstands at this location to be significantly higher than in other regions, helping to explain the high <span class="hlt">sea</span> <span class="hlt">levels</span> observed for Bermuda from earlier highstands.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70160447','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70160447"><span>Late Holocene <span class="hlt">sea</span>- and land-<span class="hlt">level</span> change on the U.S. southeastern Atlantic Coast</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Kemp, Andrew C.; Bernhardt, Christopher E.; Horton, Benjamin P.; Kopp, Robert E.; Vane, Christopher H.; Peltier, W. Richard; Hawkes, Andrea D.; Donnelly, Jeffrey P.; Parnell, Andrew C.; Cahill, Niamh</p> <p>2015-01-01</p> <p>Late Holocene relative <span class="hlt">sea-level</span> (RSL) reconstructions can be used to estimate rates of land-<span class="hlt">level</span> (subsidence or uplift) change and therefore to modify global <span class="hlt">sea-level</span> projections for regional conditions. These reconstructions also provide the long-term benchmark against which modern trends are compared and an opportunity to understand the response of <span class="hlt">sea</span> <span class="hlt">level</span> to past climate variability. To address a spatial absence of late Holocene data in Florida and Georgia, we reconstructed ~ 1.3 m of RSL rise in northeastern Florida (USA) during the past ~ 2600 years using plant remains and foraminifera in a dated core of high salt-marsh sediment. The reconstruction was fused with tide-gauge data from nearby Fernandina Beach, which <span class="hlt">measured</span> 1.91 ± 0.26 mm/year of RSL rise since 1900 CE. The average rate of RSL rise prior to 1800 CE was 0.41 ± 0.08 mm/year. Assuming negligible change in global mean <span class="hlt">sea</span> <span class="hlt">level</span> from meltwater input/removal and thermal expansion/contraction, this <span class="hlt">sea-level</span> history approximates net land-<span class="hlt">level</span> (subsidence and geoid) change, principally from glacio-isostatic adjustment. Historic rates of rise commenced at 1850–1890 CE and it is virtually certain (P = 0.99) that the average rate of 20th century RSL rise in northeastern Florida was faster than during any of the preceding 26 centuries. The linearity of RSL rise in Florida is in contrast to the variability reconstructed at sites further north on the U.S. Atlantic coast and may suggest a role for ocean dynamic effects in explaining these more variable RSL reconstructions. Comparison of the difference between reconstructed rates of late Holocene RSL rise and historic trends <span class="hlt">measured</span> by tide gauges indicates that 20th century <span class="hlt">sea-level</span> trends along the U.S. Atlantic coast were not dominated by the characteristic spatial fingerprint of melting of the Greenland Ice Sheet.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.4397Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.4397Z"><span><span class="hlt">Sea</span> <span class="hlt">level</span> rise Contribution from High Mountain Asia by 20150</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhao, Liyun; Moore, John; Ding, Ran</p> <p>2015-04-01</p> <p>We estimate individual area and volume change by 2050 of all 83,460 glaciers of high mountain Asia (HMA), with a total area of 118,263 km2, delineated in the Randolph Glacier Inventory version 4.0 which separates glacier complexes in its previous version into individual glaciers. We used the 25 km resolution regional climate model RegCM 3.0 temperature and precipitation change projections forced by the IPCC A1B scenario. Glacier simulations were based on a novel surface mass balance-altitude parameterization fitted to observational data, and various volume-area scaling approaches using Shuttle Radar Topography Mission surface topography of each individual glacier. We generate mass balance-altitude relations for all the glaciers by region using nearest available glacier <span class="hlt">measurements</span>. Two method are used to model the Equilibrium line altitude (ELA) variation. One is to use ELA sensitivities to temperature and precipitation change vary by region based on the relative importance of sublimation and melting processes. The other is solved ELA implicitly for every year using the temperature at ELA and Degree Day model. We project total glacier area loss in high mountain Asia in 2050 to be 22% of their extent in 2000, and they will contribute 5-8 mm to global <span class="hlt">sea</span> <span class="hlt">level</span> rise.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016QSRv..137...54B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016QSRv..137...54B"><span>Modelling <span class="hlt">sea</span> <span class="hlt">level</span> data from China and Malay-Thailand to estimate Holocene ice-volume equivalent <span class="hlt">sea</span> <span class="hlt">level</span> change</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bradley, Sarah L.; Milne, Glenn A.; Horton, Benjamin P.; Zong, Yongqiang</p> <p>2016-04-01</p> <p>This study presents a new model of Holocene ice-volume equivalent <span class="hlt">sea</span> <span class="hlt">level</span> (ESL), extending a previously published global ice sheet model (Bassett et al., 2005), which was unconstrained from 10 kyr BP to present. This new model was developed by comparing relative <span class="hlt">sea</span> <span class="hlt">level</span> (RSL) predictions from a glacial isostatic adjustment (GIA) model to a suite of Holocene <span class="hlt">sea</span> <span class="hlt">level</span> index points from China and Malay-Thailand. Three consistent data-model misfits were found using the Bassett et al. (2005) model: an over-prediction in the height of maximum <span class="hlt">sea</span> <span class="hlt">level</span>, the timing of this maximum, and the temporal variation of <span class="hlt">sea</span> <span class="hlt">level</span> from the time of the highstand to present. The data-model misfits were examined for a large suite of ESL scenarios and a range of earth model parameters to determine an optimum model of Holocene ESL. This model is characterised by a slowdown in melting at ∼7 kyr BP, associated with the final deglaciation of the Laurentide Ice Sheet, followed by a continued rise in ESL until ∼1 kyr BP of ∼5.8 m associated with melting from the Antarctic Ice Sheet. It was not possible to identify an earth viscosity model that provided good fits for both regions; with the China data preferring viscosity values in the upper mantle of less than 1.5 × 1020 Pa s and the Malay-Thailand data preferring greater values. We suggest that this inference of a very weak upper mantle for the China data originates from the nearby subduction zone and Hainan Plume. The low viscosity values may also account for the lack of a well-defined highstand at the China sites.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012ESASP.703E..23K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012ESASP.703E..23K"><span><span class="hlt">Sea</span>-Salt Aerosol Forecasts Compared with Wave and <span class="hlt">Sea</span>-Salt <span class="hlt">Measurements</span> in the Open Mediterranean <span class="hlt">Sea</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kishcha, P.; Starobinets, B.; Bozzano, R.; Pensieri, S.; Canepa, E.; Nickovie, S.; di Sarra, A.; Udisti, R.; Becagli, S.; Alpert, P.</p> <p>2012-03-01</p> <p><span class="hlt">Sea</span>-salt aerosol (SSA) could influence the Earth's climate acting as cloud condensation nuclei. However, there were no regular <span class="hlt">measurements</span> of SSA in the open <span class="hlt">sea</span>. At Tel-Aviv University, the DREAM-Salt prediction system has been producing daily forecasts of 3-D distribution of <span class="hlt">sea</span>-salt aerosol concentrations over the Mediterranean <span class="hlt">Sea</span> (http://wind.tau.ac.il/saltina/ salt.html). In order to evaluate the model performance in the open <span class="hlt">sea</span>, daily modeled concentrations were compared directly with SSA <span class="hlt">measurements</span> taken at the tiny island of Lampedusa, in the Central Mediterranean. In order to further test the robustness of the model, the model performance over the open <span class="hlt">sea</span> was indirectly verified by comparing modeled SSA concentrations with wave height <span class="hlt">measurements</span> collected by the ODAS Italia 1 buoy and the Llobregat buoy. Model-vs.-<span class="hlt">measurement</span> comparisons show that the model is capable of producing realistic SSA concentrations and their day-today variations over the open <span class="hlt">sea</span>, in accordance with observed wave height and wind speed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70170271','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70170271"><span>Late Holocene <span class="hlt">sea</span> <span class="hlt">level</span> variability and Atlantic Meridional Overturning Circulation</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Cronin, Thomas M.; Farmer, Jesse R.; Marzen, R. E.; Thomas, E.; Varekamp, J.C.</p> <p>2014-01-01</p> <p>Pre-twentieth century <span class="hlt">sea</span> <span class="hlt">level</span> (SL) variability remains poorly understood due to limits of tide gauge records, low temporal resolution of tidal marsh records, and regional anomalies caused by dynamic ocean processes, notably multidecadal changes in Atlantic Meridional Overturning Circulation (AMOC). We examined SL and AMOC variability along the eastern United States over the last 2000 years, using a SL curve constructed from proxy <span class="hlt">sea</span> surface temperature (SST) records from Chesapeake Bay, and twentieth century SL-<span class="hlt">sea</span> surface temperature (SST) relations derived from tide gauges and instrumental SST. The SL curve shows multidecadal-scale variability (20–30 years) during the Medieval Climate Anomaly (MCA) and Little Ice Age (LIA), as well as the twentieth century. During these SL oscillations, short-term rates ranged from 2 to 4 mm yr−1, roughly similar to those of the last few decades. These oscillations likely represent internal modes of climate variability related to AMOC variability and originating at high latitudes, although the exact mechanisms remain unclear. Results imply that dynamic ocean changes, in addition to thermosteric, glacio-eustatic, or glacio-isostatic processes are an inherent part of SL variability in coastal regions, even during millennial-scale climate oscillations such as the MCA and LIA and should be factored into efforts that use tide gauges and tidal marsh sediments to understand global <span class="hlt">sea</span> <span class="hlt">level</span> rise.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19900033471&hterms=Barometers&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DBarometers','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19900033471&hterms=Barometers&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DBarometers"><span>Seasonal variability in global <span class="hlt">sea</span> <span class="hlt">level</span> observed with Geosat altimetry</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zlotnicki, V.; Fu, L.-L.; Patzert, W.</p> <p>1989-01-01</p> <p>Time changes in global mesoscale <span class="hlt">sea</span> <span class="hlt">level</span> variances were observed with satellite altimetry between November 1986 and March 1988, showing significant, geographically coherent seasonal patterns. The NE Pacific and NE Atlantic variances show the most reliable patterns, higher than their yearly averages in both the fall and winter. The response to wind forcing appears as the major contributor to the NE Pacific and Atlantic signals; errors in the estimated inverse barometer response due to errors in atmospheric pressure, residual orbit errors, and errors in <span class="hlt">sea</span> state bias are evaluated and found to be negligible contributors to this particular signal. The equatorial regions also show significant seasonal patterns, but the uncertainties in the wet tropospheric correction prevent definitive conclusions. The western boundary current changes are very large but not statistically significant. Estimates of the regression coefficient between <span class="hlt">sea</span> <span class="hlt">level</span> and significant wave height, an estimate of the <span class="hlt">sea</span> state bias correction, range between 2.3 and 2.9 percent and vary with the type of orbit correction applied.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMGC31A1023K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMGC31A1023K"><span>Holocene <span class="hlt">Sea-Level</span> Database For The Caribbean Region</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Khan, N. S.; Horton, B.; Engelhart, S. E.; Peltier, W. R.; Scatena, F. N.; Vane, C. H.; Liu, S.</p> <p>2013-12-01</p> <p>Holocene relative <span class="hlt">sea-level</span> (RSL) records from far-field locations are important for understanding the driving mechanisms controlling the nature and timing of the mid-late Holocene reduction in global meltwaters and providing background rates of late Holocene RSL change with which to compare the magnitude of 20th century RSL rise. The Caribbean region has traditionally been considered far-field (i.e., with negligible glacio-isostatic adjustment (GIA) influence), although recent investigations indicate otherwise. Here, we consider the spatial variability in glacio-isostatic, tectonic and local contributions on RSL records from the circum-Caribbean region to infer a Holocene eustatic <span class="hlt">sea-level</span> signal. We have constructed a database of quality-controlled, spatially comprehensive, Holocene RSL observations for the circum-Caribbean region. The database contains over 500 index points, which locate the position of RSL in time and space. The database incorporates <span class="hlt">sea-level</span> observations from a latitudinal range of 5°N to 25°N and longitudinal range of 55°W to 90°W. We include <span class="hlt">sea-level</span> observations from 11 ka BP to present, although the majority of the index points in the database are younger than 8 ka BP. The database is sub-divided into 13 regions based on the distance from the former Laurentide Ice Sheet and regional tectonic setting. The index points were primarily derived from mangrove peat deposits, which in the Caribbean form in the upper half of the tidal range, and corals (predominantly Acropora palmata), the growth of which is constrained to the upper 5 m of water depth. The index points are classified on the basis of their susceptibility to compaction (e.g., intercalated, basal). The influence of temporal changes in tidal range on index points is also considered. The <span class="hlt">sea-level</span> reconstructions demonstrate that RSL did not exceed the present height (0 m) during the Holocene in the majority of locations, except at sites in Suriname/Guayana and possibly Trinidad</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013GPC...100..362Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013GPC...100..362Z"><span>Temporal scaling behavior of <span class="hlt">sea-level</span> change in Hong Kong - Multifractal temporally weighted detrended fluctuation analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Yuanzhi; Ge, Erjia</p> <p>2013-01-01</p> <p>The rise in global <span class="hlt">sea</span> <span class="hlt">levels</span> has been recognized by many scientists as an important global research issue. The process of <span class="hlt">sea-level</span> change has demonstrated a complex scaling behavior in space and time. Large numbers of tide gauge stations have been built to <span class="hlt">measure</span> <span class="hlt">sea-level</span> change in the North Pacific Ocean, Indian Ocean, North Atlantic Ocean, and Antarctic Ocean. Extensive studies have been devoted to exploring <span class="hlt">sea-level</span> variation in Asia concerning the Bohai Gulf (China), the Yellow <span class="hlt">Sea</span> (China), the Mekong Delta (Thailand), and Singapore. Hong Kong, however, a mega city with a population of over 7 million situated in the mouth of the Pear River Estuary in the west and the South China <span class="hlt">Sea</span> in the east, has yet to be studied, particularly in terms of the temporal scaling behavior of <span class="hlt">sea-level</span> change. This article presents an approach to studying the temporal scaling behavior of <span class="hlt">sea-level</span> change over multiple time scales by analyzing the time series of <span class="hlt">sea-level</span> change in Tai Po Kou, Tsim Bei Tsui, and Quarry Bay from the periods of 1964-2010, 1974-2010, and 1986-2010, respectively. The detection of long-range correlation and multi-fractality of <span class="hlt">sea-level</span> change seeks answers to the following questions: (1) Is the current <span class="hlt">sea-level</span> rise associated with and responsible for the next rise over time? (2) Does the <span class="hlt">sea-level</span> rise have specific temporal patterns manifested by multi-scaling behaviors? and (3) Is the <span class="hlt">sea-level</span> rise is temporally heterogeneous in the different parts of Hong Kong? Multi-fractal temporally weighted de-trended fluctuation analysis (MF-TWDFA), an extension of multi-fractal de-trended fluctuation analysis (MF-DFA), has been applied in this study to identify long-range correlation and multi-scaling behavior of the <span class="hlt">sea-level</span> rise in Hong Kong. The experimental results show that the <span class="hlt">sea-level</span> rise is long-range correlated and multi-fractal. The temporal patterns are heterogeneous over space. This finding implies that mechanisms associated with the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19900042550&hterms=accounting+measurement&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Daccounting%2Bmeasurement','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19900042550&hterms=accounting+measurement&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Daccounting%2Bmeasurement"><span>Effects of <span class="hlt">sea</span> maturity on satellite altimeter <span class="hlt">measurements</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Glazman, Roman E.; Pilorz, Stuart H.</p> <p>1990-01-01</p> <p>For equilibrium and near-equilibrium <span class="hlt">sea</span> states, the wave slope variance is a function of wind speed U and of the <span class="hlt">sea</span> maturity. The influence of both factors on the altimeter <span class="hlt">measurements</span> of wind speed, wave height, and radar cross section is studied experimentally on the basis of 1 year's worth of Geosat altimeter observations colocated with in situ wind and wave <span class="hlt">measurements</span> by 20 NOAA buoys. Errors and biases in altimeter wind speed and wave height <span class="hlt">measurements</span> are investigted. A geophysically significant error trend correlated with the <span class="hlt">sea</span> maturity is found in wind-speed <span class="hlt">measurements</span>. This trend is explained by examining the effect of the generalized wind fetch on the curves of the observed dependence. It is concluded that unambiguous <span class="hlt">measurements</span> of wind speed by altimeter, in a wide range of <span class="hlt">sea</span> states, are impossible without accounting for the actual degree of wave development.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003EAEJA.....8435A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA.....8435A"><span><span class="hlt">Sea</span> <span class="hlt">level</span> during roman epoch in the central Tyrrhenian <span class="hlt">sea</span> (Italy)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Anzidei, M.; Antonioli, F.; Benini, A.; Esposito, A.; Lambeck, K.; Surace, L.</p> <p>2003-04-01</p> <p>The aim of this research is to reconstruct the vertical deformations of the earth's crust and the relative <span class="hlt">sea</span> <span class="hlt">level</span> oscillations during late Holocene (2-3 ka BP) by means of multidisciplinary investigations of archaeological sites located along the central Tyrrhenian coastlines (Italy). The sites (piscinae, harbours and quarries) of pre-Roman and Roman Age, play a fundamental role for the evaluation of the <span class="hlt">sea</span> <span class="hlt">level</span> rise during the last 2.5 ka. Early studies using this technique were performed by Flemming (1969), Schmiedt (1972), Pirazzoli (1976) and more recently by Flemming and Webb (1986) and Leoni and Dai Pra (1997). We have used the original latin sources written by the historical Roman authors Varrone and Columella to understand the detailed technical rules for the construction of the piscinae (depth of ponds and channels, operating range of the sluice gates, etc.). On the basis of these publications we re-interpret some significant sites to estimate the difference between their ancient depths and some recent interpretations. We studied the remains located at Castiglioncello, Gravisca, Punta della Vipera, Santa Marinella, Torre Astura and Ventotene island. Our data show an increase in <span class="hlt">sea</span> <span class="hlt">level</span> at these sites of between 178±20 and 125±20 cm since pre-roman age (2.3-1.9 ka BP). All sites are located along about 400 km coastline of the Tyrrhenian <span class="hlt">sea</span>, from Tuscany to Latium, that exhibits areas of both tectonic stability and instability and we use the elevation of the MIS 5.5 transgression (inner margin sediments) to estimate the rates of uplift or subsidence. At Punta della Vipera this elevation reaches 35 m (Antonioli et al., 2000) and we consider that this area has been tectonically active with an uplift rate of 0.23 ± 0.05 mm yr-1. High resolution numerical models of <span class="hlt">sea-level</span> change have been used and tested against other Italian <span class="hlt">sea</span> <span class="hlt">level</span> data to provide a realistic representation of the spatial variability of the <span class="hlt">sea-level</span> change and shoreline</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ChJOL..35...79Q','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ChJOL..35...79Q"><span>Interannual to decadal variation of spring <span class="hlt">sea</span> <span class="hlt">level</span> anomaly in the western South China <span class="hlt">Sea</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Qiu, Fuwen; Fang, Wendong; Pan, Aijun; Cha, Jing; Zhang, Shanwu; Huang, Jiang</p> <p>2017-01-01</p> <p>Satellite observations of <span class="hlt">sea</span> <span class="hlt">level</span> anomalies (SLA) from January 1993 to December 2012 are used to investigate the interannual to decadal changes of the boreal spring high SLA in the western South China <span class="hlt">Sea</span> (SCS) using the Empirical Orthogonal Function (EOF) method. We find that the SLA variability has two dominant modes. The <span class="hlt">Sea</span> <span class="hlt">Level</span> Changing Mode (SLCM) occurs mainly during La Niña years, with high SLA extension from west of Luzon to the eastern coast of Vietnam along the central basin of the SCS, and is likely induced by the increment of the ocean heat content. The Anticyclonic Eddy Mode (AEM) occurs mainly during El Niño years and appears to be triggered by the negative wind curl anomalies within the central SCS. In addition, the spring high SLA in the western SCS experienced a quasi-decadal change during 1993-2012; in other words, the AEM predominated during 1993-1998 and 2002-2005, while the La Niña-related SLCM prevailed during 1999-2001 and 2006-2012. Moreover, we suggest that the accelerated <span class="hlt">sea</span> <span class="hlt">level</span> rise in the SCS during 2005-2012 makes the SLCM the leading mode over the past two decades.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22946376','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22946376"><span>Vitamin A deficiency and hepatic retinol <span class="hlt">levels</span> in <span class="hlt">sea</span> otters, Enhydra lutris.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>St Leger, Judy A; Righton, Alison L; Nilson, Erika M; Fascetti, Andrea J; Miller, Melissa A; Tuomi, Pamela A; Goertz, Caroline E C; Puschner, Birgit</p> <p>2011-03-01</p> <p>Vitamin A deficiency has rarely been reported in captive or free-ranging wildlife species. Necropsy findings in two captively housed southern <span class="hlt">sea</span> otters (Enhydra lutris nereis) included irregular thickening of the calvaria characterized by diffuse hyperostoses on the internal surface. One animal also had moderate squamous metaplasia of the seromucinous glands of the nose. There was no <span class="hlt">measurable</span> retinol in the liver of either <span class="hlt">sea</span> otter. For comparison, hepatic retinol concentration was determined for 23 deceased free-ranging southern and northern (Enhydra lutris kenyoni) <span class="hlt">sea</span> otters from California and Alaska. Free-ranging otters were found to have similar hepatic retinol concentrations (316 +/- 245 mg/kg wet weight) regardless of their location and subspecies. All of these values were significantly higher than the <span class="hlt">levels</span> in the affected animals. Consumption of a diet with very low vitamin A concentrations and noncompliance in daily supplementation are hypothesized as the causes of vitamin A deficiency in these two <span class="hlt">sea</span> otters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15042085','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15042085"><span>Mass and volume contributions to twentieth-century global <span class="hlt">sea</span> <span class="hlt">level</span> rise.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Miller, Laury; Douglas, Bruce C</p> <p>2004-03-25</p> <p>The rate of twentieth-century global <span class="hlt">sea</span> <span class="hlt">level</span> rise and its causes are the subjects of intense controversy. Most direct estimates from tide gauges give 1.5-2.0 mm yr(-1), whereas indirect estimates based on the two processes responsible for global <span class="hlt">sea</span> <span class="hlt">level</span> rise, namely mass and volume change, fall far below this range. Estimates of the volume increase due to ocean warming give a rate of about 0.5 mm yr(-1) (ref. 8) and the rate due to mass increase, primarily from the melting of continental ice, is thought to be even smaller. Therefore, either the tide gauge estimates are too high, as has been suggested recently, or one (or both) of the mass and volume estimates is too low. Here we present an analysis of <span class="hlt">sea</span> <span class="hlt">level</span> <span class="hlt">measurements</span> at tide gauges combined with observations of temperature and salinity in the Pacific and Atlantic oceans close to the gauges. We find that gauge-determined rates of <span class="hlt">sea</span> <span class="hlt">level</span> rise, which encompass both mass and volume changes, are two to three times higher than the rates due to volume change derived from temperature and salinity data. Our analysis supports earlier studies that put the twentieth-century rate in the 1.5-2.0 mm yr(-1) range, but more importantly it suggests that mass increase plays a larger role than ocean warming in twentieth-century global <span class="hlt">sea</span> <span class="hlt">level</span> rise.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70032592','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70032592"><span>Geologic effects and coastal vulnerability to <span class="hlt">sea-level</span> rise, erosion, and storms</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Williams, S.J.; Gutierrez, B.T.; Thieler, E.R.; Pendleton, E.</p> <p>2008-01-01</p> <p>A combination of natural and human factors are driving coastal change and making coastal regions and populations increasingly vulnerable. <span class="hlt">Sea</span> <span class="hlt">level</span>, a major agent of coastal erosion, has varied greatly from -120 m below present during glacial period low-stands to + 4 to 6 m above present during interglacial warm periods. Geologic and tide gauge data show that global <span class="hlt">sea</span> <span class="hlt">level</span> has risen about 12 to 15 cm during the past century with satellite <span class="hlt">measurements</span> indicating an acceleration since the early 1990s due to thermal expansion and ice-sheet melting. Land subsidence due to tectonic forces and sediment compaction in regions like the mid-Atlantic and Louisiana increase the rate of relative <span class="hlt">sea-level</span> rise to 40 cm to 100 cm per century. <span class="hlt">Sea</span>- <span class="hlt">level</span> rise is predicted to accelerate significantly in the near future due to climate change, resulting in pervasive impacts to coastal regions and putting populations increasingly at risk. The full implications of climate change for coastal systems need to be understood better and long-term plans are needed to manage coasts in order to protect natural resources and mitigate the effects of <span class="hlt">sea-level</span> rise and increased storms on human infrastructure. Copyright ASCE 2008.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SGeo...38...33C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SGeo...38...33C"><span>Monitoring <span class="hlt">Sea</span> <span class="hlt">Level</span> in the Coastal Zone with Satellite Altimetry and Tide Gauges</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cipollini, Paolo; Calafat, Francisco M.; Jevrejeva, Svetlana; Melet, Angelique; Prandi, Pierre</p> <p>2017-01-01</p> <p>We examine the issue of sustained <span class="hlt">measurements</span> of <span class="hlt">sea</span> <span class="hlt">level</span> in the coastal zone, first by summarizing the long-term observations from tide gauges, then showing how those are now complemented by improved satellite altimetry products in the coastal ocean. We present some of the progresses in coastal altimetry, both from dedicated reprocessing of the radar waveforms and from the development of improved corrections for the atmospheric effects. This trend towards better altimetric data at the coast comes also from technological innovations such as Ka-band altimetry and SAR altimetry, and we discuss the advantages deriving from the AltiKa Ka-band altimeter and the SIRAL altimeter on CryoSat-2 that can be operated in SAR mode. A case study along the UK coast demonstrates the good agreement between coastal altimetry and tide gauge observations, with root mean square differences as low as 4 cm at many stations, allowing the characterization of the annual cycle of <span class="hlt">sea</span> <span class="hlt">level</span> along the UK coasts. Finally, we examine the evolution of the <span class="hlt">sea</span> <span class="hlt">level</span> trend from the open to the coastal ocean along the western coast of Africa, comparing standard and coastally improved products. Different products give different <span class="hlt">sea</span> <span class="hlt">level</span> trend profiles, so the recommendation is that additional efforts are needed to study <span class="hlt">sea</span> <span class="hlt">level</span> trends in the coastal zone from past and present satellite altimeters. Further improvements are expected from more refined processing and screening of data, but in particular from the constant improvements in the geophysical corrections.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ERL....10l4022B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ERL....10l4022B"><span>US power plant sites at risk of future <span class="hlt">sea-level</span> rise</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bierkandt, R.; Auffhammer, M.; Levermann, A.</p> <p>2015-12-01</p> <p>Unmitigated greenhouse gas emissions may increase global mean <span class="hlt">sea-level</span> by about 1 meter during this century. Such elevation of the mean <span class="hlt">sea-level</span> enhances the risk of flooding of coastal areas. We compute the power capacity that is currently out-of-reach of a 100-year coastal flooding but will be exposed to such a flood by the end of the century for different US states, if no adaptation <span class="hlt">measures</span> are taken. The additional exposed capacity varies strongly among states. For Delaware it is 80% of the mean generated power load. For New York this number is 63% and for Florida 43%. The capacity that needs additional protection compared to today increases by more than 250% for Texas, 90% for Florida and 70% for New York. Current development in power plant building points towards a reduced future exposure to <span class="hlt">sea-level</span> rise: proposed and planned power plants are less exposed than those which are currently operating. However, power plants that have been retired or canceled were less exposed than those operating at present. If <span class="hlt">sea-level</span> rise is properly accounted for in future planning, an adaptation to <span class="hlt">sea-level</span> rise may be costly but possible.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004E%26PSL.224..563L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004E%26PSL.224..563L"><span><span class="hlt">Sea</span> <span class="hlt">level</span> in Roman time in the Central Mediterranean and implications for recent change</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lambeck, Kurt; Anzidei, Marco; Antonioli, Fabrizio; Benini, Alessandra; Esposito, Alessandra</p> <p>2004-08-01</p> <p>Instrumental records indicate that ocean volumes during the 20th century have increased so as to raise eustatic <span class="hlt">sea</span> <span class="hlt">level</span> by ˜1-2 mm/year and the few available records suggest that this is higher than for the previous century. Geological data indicate that ocean volumes have increased since the main phase of deglaciation about 7000 years ago but whether this continued into the recent past remains unclear. Yet, this is important for establishing whether the recent rise is associated with global warming or is part of a longer duration non-anthropogenic signal. Here, we present results for <span class="hlt">sea-level</span> change in the central Mediterranean basin for the Roman Period using new archaeological evidence. These data provide a precise <span class="hlt">measure</span> of local <span class="hlt">sea</span> <span class="hlt">level</span> of -1.35±0.07 m at 2000 years ago. Part of this change is the result of ongoing glacio-hydro isostatic adjustment of the crust subsequent to the last deglaciation. When corrected for this, using geologically constrained model predictions, the change in eustatic <span class="hlt">sea</span> <span class="hlt">level</span> since the Roman Period is -0.13±0.09 m. A comparison with tide-gauge records from nearby locations and with geologically constrained model predictions of the glacio-isostatic contributions establishes that the onset of modern <span class="hlt">sea-level</span> rise occurred in recent time at ˜100±53 years before present.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70011660','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70011660"><span>Holocene changes in <span class="hlt">sea</span> <span class="hlt">level</span>: Evidence in Micronesia</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Shepard, F.P.; Curray, Joseph R.; Newman, W.A.; Bloom, A.L.; Newell, N.D.; Tracey, J.I.; Veeh, H.H.</p> <p>1967-01-01</p> <p>Investigation of 33 islands, scattered widely across the Caroline and Marshall Island groups in the Central Pacific revealed no emerged reefs in which corals had unquestionably formed in situ, or other direct evidence of postglacial high stands of <span class="hlt">sea</span> <span class="hlt">level</span>. Low unconsolidated rock terraces and ridges of reef-flat islands, mostly lying between tide <span class="hlt">levels</span>, were composed of rubble conglomerates; carbon-14 dating of 11 samples from the conglomerates so far may suggest a former slightly higher <span class="hlt">sea</span> <span class="hlt">level</span> (nine samples range between 1890 and 3450 and one approaches 4500 years ago). However, recent hurricanes have produced ridges of comparable height and material, and in the same areas relics from World War II have been found cemented in place. Thus these datings do not in themselves necessarily indicate formerly higher <span class="hlt">sea</span> <span class="hlt">levels</span>. Rubble tracts are produced by storms under present conditions without any change in datum, and there seems to be no compelling evidence that they were not so developed during various periods in the past.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11.1617B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11.1617B"><span>Global increasing of mean <span class="hlt">sea</span> <span class="hlt">level</span> and erroneous treatment of a role of thermal factors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barkin, Yu. V.</p> <p>2009-04-01</p> <p> in the northern hemisphere. At averaging of <span class="hlt">measurements</span> over all ocean surface (mainly located in a southern hemisphere where it occupies about 80 % of the areas) there will be an effect of apparent additional increase of the <span class="hlt">sea</span> <span class="hlt">level</span>. Therefore this ("apparent") velocity of increase of the <span class="hlt">sea</span> <span class="hlt">level</span> accepts the greater value (about 2.4 mm / year) in comparison with coastal determinations of this velocity that is rather close to the data of satellite observations. The additional effect in increase of the <span class="hlt">sea</span> <span class="hlt">level</span> is brought by deformation of the ocean bottom. The both mentioned phenomena: the secular drift of the center of mass of the Earth and the secular expansion of southern hemisphere of the Earth have been predicted by author [2], [3] and have obtained confirmations by space geodesy methods. The offered explanation has the extremely - important value for studying a possible role of thermal and climatic factors which can not apply any more for a big component attributed to it in change of the <span class="hlt">sea</span> <span class="hlt">level</span>. The account of fictitious component of this velocity results practically in real value of variation of the average <span class="hlt">sea</span> <span class="hlt">level</span> about 1.3-1.6 mm / yr, that completely coordinate positions of researchers of ocean by coastal and altimetry (satellite) methods. Moreover, the given work opens a direct opportunity for an explanation of increase of the <span class="hlt">sea</span> <span class="hlt">level</span> as result of deformation of the ocean bottom. This deformation is a major factor of change of the average <span class="hlt">sea</span> <span class="hlt">level</span>. Water superseded in a southern hemisphere gives the significant contribution to observably value of velocity of <span class="hlt">sea</span> <span class="hlt">level</span> rise up to 0.8-1.2 mm / yr [3, 4]. The work fulfilled at financial support of Russian projects of RFBR: N 07-05-00939 and N 06-02-16665. This abstract (without what or changes) has been accepted to EGU GA 2008 Session IS48 "75th Anniversary of the PSML"(Convener: Woodworth P.) but was not included in its program. References. [1] Nerem R.S., Leuliette E.W., Chambers D.P. (2005</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.3039H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.3039H"><span>Reconstruction of Late Holocene <span class="hlt">sea-level</span> change in French Polynesia, South Pacific, based on coral reef records</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hallmann, Nadine; Camoin, Gilbert; Eisenhauer, Anton; Vella, Claude</p> <p>2013-04-01</p> <p>Fossil reefs provide valuable <span class="hlt">sea-level</span> indicators, which help to improve the understanding of past <span class="hlt">sea-level</span> fluctuations and the prediction of future changes. Recent <span class="hlt">sea-level</span> changes were reconstructed from emerged reef platforms of two high islands from the Society Islands (Bora Bora, Moorea) and two atolls from the Tuamotu Archipelago (Rangiroa, Tikehau), French Polynesia. These mid-ocean islands can be regarded as tectonically stable for the past few thousand years. Therefore, they are well suited for <span class="hlt">sea-level</span> studies because they register Holocene eustatic changes, which are not overprinted by tectonic changes. Furthermore, the study sites are located distant from former ice sheets (far field location), which reduces the influence of the glacio-isostatic rebound. Several <span class="hlt">sea-level</span> indicators, such as in situ coral colonies, including coral microatolls (Porites sp.), bivalves (mainly Tridacna sp.), conglomerates, beachrock, and sediments were analyzed in order to reconstruct Late Holocene relative <span class="hlt">sea-level</span> changes. Microatolls are discoid corals that develop laterally when upward growth is limited by <span class="hlt">sea-level</span>. Therefore, they are very accurate recorders of past <span class="hlt">sea-level</span>. This study provides a detailed <span class="hlt">sea-level</span> history for French Polynesia using high-precision U/Th (TIMS) dating and GPS <span class="hlt">measurements</span> with a vertical and horizontal precision of 1-3 cm and a few millimetres, respectively. All samples were analyzed by X-ray diffraction and examined petrographically to exclude diagenetically altered material. The Holocene mean <span class="hlt">sea</span> <span class="hlt">level</span> in French Polynesia was thought to have been higher than present (+0.8/+1.0 m) between 5000 and 1250 yr BP, reached a highstand between 2000 and 1500 yr BP and then decreased to the present <span class="hlt">level</span> (Pirazzoli and Montaggioni, 1988). The highstand has been reported until 1200 yr BP in the Tuamotu Archipelago (Pirazzoli and Montaggioni, 1986). However, <span class="hlt">sea-level</span> indicators analyzed in this study reveal a highstand of at least 1.5 m</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009ERL.....4d1001H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009ERL.....4d1001H"><span>PERSPECTIVE: The tripping points of <span class="hlt">sea</span> <span class="hlt">level</span> rise</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hecht, Alan D.</p> <p>2009-12-01</p> <p>When President Nixon created the US Environmental Protection Agency (EPA) in 1970 he said the environment must be perceived as a single, interrelated system. We are nowhere close to achieving this vision. Jim Titus and his colleagues [1] highlight one example of where one set of regulations or permits may be in conflict with another and where regulations were crafted in the absence of understanding the cumulative impact of global warming. The issue here is how to deal with the impacts of climate change on <span class="hlt">sea</span> <span class="hlt">level</span> and the latter's impact on wetland polices, clean water regulations, and ecosystem services. The Titus paper could also be called `The tripping points of <span class="hlt">sea</span> <span class="hlt">level</span> rise'. Titus and his colleagues have looked at the impact of such <span class="hlt">sea</span> <span class="hlt">level</span> rise on the east coast of the United States. Adaptive responses include costly large- scale investment in shore protection (e.g. dikes, sand replenishment) and/or ecosystem migration (retreat), where coastal ecosystems move inland. Shore protection is limited by available funds, while ecosystem migrations are limited by available land use. The driving factor is the high probability of <span class="hlt">sea</span> <span class="hlt">level</span> rise due to climate change. Estimating <span class="hlt">sea</span> <span class="hlt">level</span> rise is difficult because of local land and coastal dynamics including rising or falling land areas. It is estimated that <span class="hlt">sea</span> <span class="hlt">level</span> could rise between 8 inches and 2 feet by the end of this century [2]. The extensive data analysis done by Titus et al of current land use is important because, as they observe, `property owners and land use agencies have generally not decided how they will respond to <span class="hlt">sea</span> <span class="hlt">level</span> rise, nor have they prepared maps delineating where shore protection and retreat are likely'. This is the first of two `tripping points', namely the need for adaptive planning for a pending environmental challenge that will create economic and environment conflict among land owners, federal and state agencies, and businesses. One way to address this gap in adaptive management</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=oceans&pg=6&id=EJ920579','ERIC'); return false;" href="http://eric.ed.gov/?q=oceans&pg=6&id=EJ920579"><span>Flooded! An Investigation of <span class="hlt">Sea-Level</span> Rise in a Changing Climate</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Gillette, Brandon; Hamilton, Cheri</p> <p>2011-01-01</p> <p>Explore how melting ice sheets affect global <span class="hlt">sea</span> <span class="hlt">levels</span>. <span class="hlt">Sea-level</span> rise (SLR) is a rise in the water <span class="hlt">level</span> of the Earth's oceans. There are two major kinds of ice in the polar regions: <span class="hlt">sea</span> ice and land ice. Land ice contributes to SLR and <span class="hlt">sea</span> ice does not. This article explores the characteristics of <span class="hlt">sea</span> ice and land ice and provides some hands-on…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17801535','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17801535"><span>Milankovitch forcing of the last interglacial <span class="hlt">sea</span> <span class="hlt">level</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Crowley, T J; Kim, K Y</p> <p>1994-09-09</p> <p>During the last interglacial, <span class="hlt">sea</span> <span class="hlt">level</span> was as high as present, 4000 to 6000 years before peak Northern Hemisphere insolation receipt 126,000 years ago. The <span class="hlt">sea-level</span> results are shown to be consistent with climate models, which simulate a 3 degrees to 4 degrees C July temperature increase from 140,000 to 130,000 years ago in high latitudes, with all Northern Hemisphere land areas being warmer than present by 130,000 years ago. The early warming occurs because obliquity peaked earlier than precession and because precession values were greater than present before peak precessional forcing occurred. These results indicate that a fuller understanding of the Milankovitch-climate connection requires consideration of fields other than just insolation forcing at 65 degrees N.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999EOSTr..80..103G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999EOSTr..80..103G"><span>Holocene Antarctic's coastal environment, ice sheet, and <span class="hlt">sea</span> <span class="hlt">levels</span> explored</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Goodwin, I.; Berkman, P.; Hjort, C.; Hirakawa, K.</p> <p></p> <p>Efforts are in the works to resolve a several-decade-long debate over the size and extent of the Antarctic ice sheet and its role in <span class="hlt">sea</span> <span class="hlt">levels</span> during the last glacial cycle. Researchers also want to find out more about the nature of environmental changes around the Antarctic coast throughout the Holocene, the sensitivity of the ice sheet to warm periods, and the significance of pre-Holocene marine fossils there.Scientists concerned with these issues presented their research priorities last fall at an Antarctic ice margin evolution (ANTIME) workshop, “Circum-Antarctic Coastal Environmental Variability and <span class="hlt">Sea</span> <span class="hlt">Level</span> History During the Late Quaternary.” These workshop participants included coastal and glacial geomorphologists, geochemists, and paleoecologists.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70013881','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70013881"><span>Contribution of small glaciers to global <span class="hlt">sea</span> <span class="hlt">level</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Meier, M.F.</p> <p>1984-01-01</p> <p>Observed long-term changes in glacier volume and hydrometeorological mass balance models yield data on the transfer of water from glaciers, excluding those in Greenland and Antarctica, to the oceans, The average observed volume change for the period 1900 to 1961 is scaled to a global average by use of the seasonal amplitude of the mass balance. These data are used to calibrate the models to estimate the changing contribution of glaciers to <span class="hlt">sea</span> <span class="hlt">level</span> for the period 1884 to 1975. Although the error band is large, these glaciers appear to accountfor a third to half of observed rise in <span class="hlt">sea</span> <span class="hlt">level</span>, approximately that fraction not explained by thermal expansion of the ocean.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4978990','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4978990"><span>Is the detection of accelerated <span class="hlt">sea</span> <span class="hlt">level</span> rise imminent?</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Fasullo, J. T.; Nerem, R. S.; Hamlington, B.</p> <p>2016-01-01</p> <p>Global mean <span class="hlt">sea</span> <span class="hlt">level</span> rise estimated from satellite altimetry provides a strong constraint on climate variability and change and is expected to accelerate as the rates of both ocean warming and cryospheric mass loss increase over time. In stark contrast to this expectation however, current altimeter products show the rate of <span class="hlt">sea</span> <span class="hlt">level</span> rise to have decreased from the first to second decades of the altimeter era. Here, a combined analysis of altimeter data and specially designed climate model simulations shows the 1991 eruption of Mt Pinatubo to likely have masked the acceleration that would have otherwise occurred. This masking arose largely from a recovery in ocean heat content through the mid to late 1990 s subsequent to major heat content reductions in the years following the eruption. A consequence of this finding is that barring another major volcanic eruption, a detectable acceleration is likely to emerge from the noise of internal climate variability in the coming decade. PMID:27506974</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=350421','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=350421"><span>Relative <span class="hlt">sea</span> <span class="hlt">levels</span> from tide-gauge records</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Emery, K. O.</p> <p>1980-01-01</p> <p>Mean annual <span class="hlt">sea</span> <span class="hlt">levels</span> at 247 tide-gauge stations of the world exhibit a general rise of relative <span class="hlt">sea</span> <span class="hlt">level</span> of about 3 mm/year during the past 40 years. In contrast, general uplift of the land is typical of high northern latitudes, where unloading of the crust by melt of Pleistocene ice sheets is significant. Erratic movements are typical of belts having crustal overthrusting and active volcanism. Short-term (5- and 10-year) records reveal recent changes in rates, but such short time spans may be so influenced by climatic cycles that identification of new trends is difficult, especially with the existing poor distribution and reporting of tide-gauge data. Images PMID:16592929</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014GeoRL..41.4970R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014GeoRL..41.4970R"><span>Control of Quaternary <span class="hlt">sea-level</span> changes on gas seeps</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Riboulot, Vincent; Thomas, Yannick; Berné, Serge; Jouet, Gwénaël.; Cattaneo, Antonio</p> <p>2014-07-01</p> <p>Gas seeping to the seafloor through structures such as pockmarks may contribute significantly to the enrichment of atmospheric greenhouse gases and global warming. Gas seeps in the Gulf of Lions, Western Mediterranean, are cyclical, and pockmark "life" is governed both by sediment accumulation on the continental margin and Quaternary climate changes. Three-dimensional seismic data, correlated to multi-proxy analysis of a deep borehole, have shown that these pockmarks are associated with oblique chimneys. The prograding chimney geometry demonstrates the syn-sedimentary and long-lasting functioning of the gas seeps. Gas chimneys have reworked chronologically constrained stratigraphic units and have functioned episodically, with maximum activity around <span class="hlt">sea</span> <span class="hlt">level</span> lowstands. Therefore, we argue that one of the main driving mechanisms responsible for their formation is the variation in hydrostatic pressure driven by relative <span class="hlt">sea</span> <span class="hlt">level</span> changes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6481137','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6481137"><span>Relative <span class="hlt">sea</span> <span class="hlt">levels</span> from tide-gauge records</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Emery, K.O.</p> <p>1980-12-01</p> <p>Mean annual <span class="hlt">sea</span> <span class="hlt">levels</span> at 247 tide-gauge stations of the world exhibit a general rise of relative <span class="hlt">sea</span> <span class="hlt">level</span> of about 3 mm/year during the past 40 years. In contrast, general uplift of the land is typical of high northern latitudes, where unloading of the crust by melt of Pleistocene ice sheets is significant. Erratic movements are typical of belts having crustal overthrusting and active volcanism. Short-term (5- and 10-year) records reveal recent changes in rates, but such short time spans may be so influenced by climatic cycles that identification of new trends is difficult, especially with the existing poor distribution and reporting of tide-gauge data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27506974','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27506974"><span>Is the detection of accelerated <span class="hlt">sea</span> <span class="hlt">level</span> rise imminent?</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fasullo, J T; Nerem, R S; Hamlington, B</p> <p>2016-08-10</p> <p>Global mean <span class="hlt">sea</span> <span class="hlt">level</span> rise estimated from satellite altimetry provides a strong constraint on climate variability and change and is expected to accelerate as the rates of both ocean warming and cryospheric mass loss increase over time. In stark contrast to this expectation however, current altimeter products show the rate of <span class="hlt">sea</span> <span class="hlt">level</span> rise to have decreased from the first to second decades of the altimeter era. Here, a combined analysis of altimeter data and specially designed climate model simulations shows the 1991 eruption of Mt Pinatubo to likely have masked the acceleration that would have otherwise occurred. This masking arose largely from a recovery in ocean heat content through the mid to late 1990 s subsequent to major heat content reductions in the years following the eruption. A consequence of this finding is that barring another major volcanic eruption, a detectable acceleration is likely to emerge from the noise of internal climate variability in the coming decade.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70014916','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70014916"><span>The record of Pliocene <span class="hlt">sea-level</span> change at Enewetak Atoll</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Wardlaw, B.R.; Quinn, T.M.</p> <p>1991-01-01</p> <p>Detailed seismic stratigraphy, lithostratigraphy, and chemostratigraphy indicate that atoll-wide subaerial exposure surfaces (major disconformities) developed during major <span class="hlt">sea-level</span> lowstands form prominent seismic reflectors and are coincident with biostratigraphic breaks in the Plio-Pleistocene on Enewetak Atoll. <span class="hlt">Sea-level</span> models based on the stratigraphic position and age of major disconformities suggest a maximum <span class="hlt">sea-level</span> highstand elevation of 36 m above present <span class="hlt">sea</span> <span class="hlt">level</span> and a maximum <span class="hlt">sea-level</span> lowstand elevation of 63 m below present <span class="hlt">sea</span> <span class="hlt">level</span> for the Pliocene. ?? 1991.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1991QSRv...10..247W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1991QSRv...10..247W"><span>The record of Pliocene <span class="hlt">sea-level</span> change at Enewetak Atoll</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wardlaw, Bruce R.; Quinn, Terrence M.</p> <p></p> <p>Detailed seismic stratigraphy, lithostratigraphy, and chemostratigraphy indicate that atoll-wide subaerial exposure surfaces (major disconformities) developed during major <span class="hlt">sea-level</span> lowstands form prominent seismic reflectors and are coincident with biostratigraphic breaks in the Plio-Pleistocene on Enewetak Atoll. <span class="hlt">Sea-level</span> models based on the stratigraphic position and age of major disconformities suggest a maximum <span class="hlt">sea-level</span> highstand elevation of 36 m above present <span class="hlt">sea</span> <span class="hlt">level</span> and a maximum <span class="hlt">sea-level</span> lowstand elevation of 63 m below present <span class="hlt">sea</span> <span class="hlt">level</span> for the Pliocene.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.2702B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.2702B"><span><span class="hlt">Sea</span> ice thickness in the Weddell <span class="hlt">Sea</span>, inferred from upward looking sonar <span class="hlt">measurements</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Behrendt, Axel; Dierking, Wolfgang; Witte, Hannelore</p> <p>2014-05-01</p> <p><span class="hlt">Sea</span> ice has been routinely monitored by satellites since 1979. However, thickness <span class="hlt">measurements</span> of <span class="hlt">sea</span> ice are still very sparse, especially in the Southern Hemisphere. Satellite altimetry still provides relatively uncertain estimates of ice thickness. Today, the only tool for monitoring <span class="hlt">sea</span> ice thickness over long time periods with highest accuracy (5-10 cm) are moored upward looking sonars (ULS). The instruments <span class="hlt">measure</span> the subsurface portion (draft) of the ice, which can be converted into total ice thickness. We present a data set of ULS time series from 13 positions in the Atlantic sector of the Southern Ocean (Weddell <span class="hlt">Sea</span>), which were made in different years between 1990 and 2010. Monthly mean <span class="hlt">sea</span> ice draft shows high interannual variability and can reach more than 3 m in the dynamic coastal regions of the eastern and western Weddell <span class="hlt">Sea</span>. The thinnest ice is found away from the coast in the eastern Weddell <span class="hlt">Sea</span> and rarely exceeds 1 m in the monthly mean. In single years the ULS data allow for a clear discrimination between thermodynamic ice growth and dynamic ice growth due to rafting and ridging of the floes. We demonstrate that the thermodynamic ice thickness can reach its theoretical maximum value of 1 m in the central Weddell basin. Despite significant gaps, the presented data set provides an important validation tool for satellite algorithms and <span class="hlt">sea</span> ice models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/fs/0091-97/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/fs/0091-97/report.pdf"><span>Global warming, <span class="hlt">sea-level</span> rise, and coastal marsh survival</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Cahoon, Donald R.</p> <p>1997-01-01</p> <p>Coastal wetlands are among the most productive ecosystems in the world. These wetlands at the land-ocean margin provide many direct benefits to humans, including habitat for commercially important fisheries and wildlife; storm protection; improved water quality through sediment, nutrient, and pollution removal; recreation; and aesthetic values. These valuable ecosystems will be highly vulnerable to the effects of the rapid rise in <span class="hlt">sea</span> <span class="hlt">level</span> predicted to occur during the next century as a result of global warming.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014APS..MARF18014C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014APS..MARF18014C"><span>Deriving the microstructural parameters of <span class="hlt">sea</span> foam from experimental <span class="hlt">measurements</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chan, Wai Soen; Lee, Hon Ping; Yu, Kin Wah</p> <p>2014-03-01</p> <p>We have studied the effective dielectric constant of <span class="hlt">sea</span> foam by exploiting its spectral structure. We have considered <span class="hlt">sea</span> foam as a two-phase composite containing air and <span class="hlt">sea</span> water, at scale where the quasi-static limit is valid. McPhedran and co-workers derived tight bounds of the structural parameters of such composite when a set of <span class="hlt">measured</span> data is given. However, determining the exact structural parameters have not been successful. We have performed an inverse algorithm, attempted to determine the structure of the foam given <span class="hlt">measured</span> data of dielectric constant. We model the <span class="hlt">sea</span> foam by a multilayered Hashin-Shtrikman structure consisting of air embedded in <span class="hlt">sea</span> water with decreasing air volume fraction from the top to bottom. We first express the effective permittivity of the foam using spectral representation as proposed by Bergman and Milton. Then, by an optimization approach, we determine the spectral parameters, namely the zeros and poles. Next, we convert these spectral parameters into structural parameters by an algorithm proposed by Sun and Yu. Hence the structure of foam could be determined. The inverse problem of determining the <span class="hlt">sea</span> foam structure is important in marine science. <span class="hlt">Sea</span> surface wind speed and salinity could be determined from properties of <span class="hlt">sea</span> foam.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/638181','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/638181"><span>Glacier calving, dynamics, and <span class="hlt">sea-level</span> rise. Final report</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Meier, M.F.; Pfeffer, W.T.; Amadei, B.</p> <p>1998-08-01</p> <p>The present-day calving flux from Greenland and Antarctica is poorly known, and this accounts for a significant portion of the uncertainty in the current mass balance of these ice sheets. Similarly, the lack of knowledge about the role of calving in glacier dynamics constitutes a major uncertainty in predicting the response of glaciers and ice sheets to changes in climate and thus <span class="hlt">sea</span> <span class="hlt">level</span>. Another fundamental problem has to do with incomplete knowledge of glacier areas and volumes, needed for analyses of <span class="hlt">sea-level</span> change due to changing climate. The authors proposed to develop an improved ability to predict the future contributions of glaciers to <span class="hlt">sea</span> <span class="hlt">level</span> by combining work from four research areas: remote sensing observations of calving activity and iceberg flux, numerical modeling of glacier dynamics, theoretical analysis of the calving process, and numerical techniques for modeling flow with large deformations and fracture. These four areas have never been combined into a single research effort on this subject; in particular, calving dynamics have never before been included explicitly in a model of glacier dynamics. A crucial issue that they proposed to address was the general question of how calving dynamics and glacier flow dynamics interact.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6119945','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6119945"><span>A Mid-Holocene <span class="hlt">sea</span> <span class="hlt">level</span> fluctuation in South Carolina</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gayes, P.T.; Nelson, D.D. . Marine and Wetland Studies); Scott, D.B.; Collins, E. . Centre for Marine Geology)</p> <p>1993-03-01</p> <p>A high stand of relative <span class="hlt">sea</span> <span class="hlt">level</span> occurred at 4.2 ka in Murrells Inlet on the northern coast of South Carolina. The event was identified using benthic foraminiferal zonations, marsh stratigraphic relations and radiocarbon data. This highstand reached a maximum of approximately [minus]1 meter MSD and was followed by a fall of 2 meters until 3.6 ka. Subsequent to 3.6 ka submergence was slow averaging 10 cm/century to the present. A second smaller fluctuation may have occurred around 2.5 ka but remains poorly constrained. Although a Mid-Holocene highstand had been suggested by others, it has not been well constrained. New data from North Inlet, South Carolina also record a baselevel change in the Mid-Holocene. Strong differential submergence between Murrells Inlet and Santee Delta, South Carolina, has occurred over the last 4 ka, probably as a result of sediment loading by and subsidence of, the Santee Delta. The occurrence of the 4.2 ka highstand corresponds in the range (7 [minus] 4 ka) to that of the Holocene Hypsithermal. The rate and magnitude of the relative <span class="hlt">sea</span> <span class="hlt">level</span> fluctuation are similar to those projected for future flooding and suggest that the evaluation of the Hypsithermal highstand may provide an insight to continued <span class="hlt">sea-level</span> rise.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730009903','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730009903"><span>Objective <span class="hlt">sea</span> <span class="hlt">level</span> pressure analysis for sparse data areas</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Druyan, L. M.</p> <p>1972-01-01</p> <p>A computer procedure was used to analyze the pressure distribution over the North Pacific Ocean for eleven synoptic times in February, 1967. Independent knowledge of the central pressures of lows is shown to reduce the analysis errors for very sparse data coverage. The application of planned remote sensing of <span class="hlt">sea-level</span> wind speeds is shown to make a significant contribution to the quality of the analysis especially in the high gradient mid-latitudes and for sparse coverage of conventional observations (such as over Southern Hemisphere oceans). Uniform distribution of the available observations of <span class="hlt">sea-level</span> pressure and wind velocity yields results far superior to those derived from a random distribution. A generalization of the results indicates that the average lower limit for analysis errors is between 2 and 2.5 mb based on the perfect specification of the magnitude of the <span class="hlt">sea-level</span> pressure gradient from a known verification analysis. A less than perfect specification will derive from wind-pressure relationships applied to satellite observed wind speeds.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70098419','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70098419"><span>How mangrove forests adjust to rising <span class="hlt">sea</span> <span class="hlt">level</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Krauss, Ken W.; McKee, Karen L.; Lovelock, Catherine E.; Cahoon, Donald R.; Saintilan, Neil; Reef, Ruth; Chen, Luzhen</p> <p>2014-01-01</p> <p>Mangroves are among the most well described and widely studied wetland communities in the world. The greatest threats to mangrove persistence are deforestation and other anthropogenic disturbances that can compromise habitat stability and resilience to <span class="hlt">sea-level</span> rise. To persist, mangrove ecosystems must adjust to rising <span class="hlt">sea</span> <span class="hlt">level</span> by building vertically or become submerged. Mangroves may directly or indirectly influence soil accretion processes through the production and accumulation of organic matter, as well as the trapping and retention of mineral sediment. In this review, we provide a general overview of research on mangrove elevation dynamics, emphasizing the role of the vegetation in maintaining soil surface elevations (i.e. position of the soil surface in the vertical plane). We summarize the primary ways in which mangroves may influence sediment accretion and vertical land development, for example, through root contributions to soil volume and upward expansion of the soil surface. We also examine how hydrological, geomorphological and climatic processes may interact with plant processes to influence mangrove capacity to keep pace with rising <span class="hlt">sea</span> <span class="hlt">level</span>. We draw on a variety of studies to describe the important, and often under-appreciated, role that plants play in shaping the trajectory of an ecosystem undergoing change.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70148342','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70148342"><span><span class="hlt">Sea</span> <span class="hlt">level</span>, paleogeography, and archeology on California's Northern Channel Islands</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Reeder-Myers, Leslie; Erlandson, Jon M.; Muhs, Daniel R.; Rick, Torben C.</p> <p>2015-01-01</p> <p><span class="hlt">Sea-level</span> rise during the late Pleistocene and early Holocene inundated nearshore areas in many parts of the world, producing drastic changes in local ecosystems and obscuring significant portions of the archeological record. Although global forces are at play, the effects of <span class="hlt">sea-level</span> rise are highly localized due to variability in glacial isostatic adjustment (GIA) effects. Interpretations of coastal paleoecology and archeology require reliable estimates of ancient shorelines that account for GIA effects. Here we build on previous models for California's Northern Channel Islands, producing more accurate late Pleistocene and Holocene paleogeographic reconstructions adjusted for regional GIA variability. This region has contributed significantly to our understanding of early New World coastal foragers. <span class="hlt">Sea</span> <span class="hlt">level</span> that was about 80–85 m lower than present at the time of the first known human occupation brought about a landscape and ecology substantially different than today. During the late Pleistocene, large tracts of coastal lowlands were exposed, while a colder, wetter climate and fluctuating marine conditions interacted with rapidly evolving littoral environments. At the close of the Pleistocene and start of the Holocene, people in coastal California faced shrinking land, intertidal, and subtidal zones, with important implications for resource availability and distribution.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5028851','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5028851"><span><span class="hlt">Sea</span> <span class="hlt">level</span> rise in Louisiana and Gulf of Mexico</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ramsey, K.; Penland, S. )</p> <p>1989-09-01</p> <p>Data from two tide-gage networks in Louisiana and the northern Gulf of Mexico were analyzed to determine local and regional trends in relative <span class="hlt">sea</span> <span class="hlt">level</span> rise. The US Army Corps of Engineers (USACE) maintains a network of 83 tide-gage stations throughout coastal Louisiana. Of these, 20 have records for two lunar nodal cycles or more, and some date back to 1933. The authors used the USACE data set to determine the local and regional character of relative <span class="hlt">sea</span> <span class="hlt">level</span> rise in Louisiana. The National ocean Survey (NOS) maintains nine tide gage stations throughout the northern Gulf of Mexico in Texas, Louisiana, Mississippi, Alabama, and Florida. All of the records of these stations exceed two lunar nodal cycles, and some date back to 1908. The authors used the NOS data set to determine the character of relative <span class="hlt">sea</span> <span class="hlt">level</span> rise throughout the northern Gulf of Mexico. This investigation updates and extends the previous systematic regional tide gage analysis (which covered 1908-1983) to 1988.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24251960','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24251960"><span>How mangrove forests adjust to rising <span class="hlt">sea</span> <span class="hlt">level</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Krauss, Ken W; McKee, Karen L; Lovelock, Catherine E; Cahoon, Donald R; Saintilan, Neil; Reef, Ruth; Chen, Luzhen</p> <p>2014-04-01</p> <p>Mangroves are among the most well described and widely studied wetland communities in the world. The greatest threats to mangrove persistence are deforestation and other anthropogenic disturbances that can compromise habitat stability and resilience to <span class="hlt">sea-level</span> rise. To persist, mangrove ecosystems must adjust to rising <span class="hlt">sea</span> <span class="hlt">level</span> by building vertically or become submerged. Mangroves may directly or indirectly influence soil accretion processes through the production and accumulation of organic matter, as well as the trapping and retention of mineral sediment. In this review, we provide a general overview of research on mangrove elevation dynamics, emphasizing the role of the vegetation in maintaining soil surface elevations (i.e. position of the soil surface in the vertical plane). We summarize the primary ways in which mangroves may influence sediment accretion and vertical land development, for example, through root contributions to soil volume and upward expansion of the soil surface. We also examine how hydrological, geomorphological and climatic processes may interact with plant processes to influence mangrove capacity to keep pace with rising <span class="hlt">sea</span> <span class="hlt">level</span>. We draw on a variety of studies to describe the important, and often under-appreciated, role that plants play in shaping the trajectory of an ecosystem undergoing change.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015QuRes..83..263R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015QuRes..83..263R"><span><span class="hlt">Sea</span> <span class="hlt">level</span>, paleogeography, and archeology on California's Northern Channel Islands</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reeder-Myers, Leslie; Erlandson, Jon M.; Muhs, Daniel R.; Rick, Torben C.</p> <p>2015-03-01</p> <p><span class="hlt">Sea-level</span> rise during the late Pleistocene and early Holocene inundated nearshore areas in many parts of the world, producing drastic changes in local ecosystems and obscuring significant portions of the archeological record. Although global forces are at play, the effects of <span class="hlt">sea-level</span> rise are highly localized due to variability in glacial isostatic adjustment (GIA) effects. Interpretations of coastal paleoecology and archeology require reliable estimates of ancient shorelines that account for GIA effects. Here we build on previous models for California's Northern Channel Islands, producing more accurate late Pleistocene and Holocene paleogeographic reconstructions adjusted for regional GIA variability. This region has contributed significantly to our understanding of early New World coastal foragers. <span class="hlt">Sea</span> <span class="hlt">level</span> that was about 80-85 m lower than present at the time of the first known human occupation brought about a landscape and ecology substantially different than today. During the late Pleistocene, large tracts of coastal lowlands were exposed, while a colder, wetter climate and fluctuating marine conditions interacted with rapidly evolving littoral environments. At the close of the Pleistocene and start of the Holocene, people in coastal California faced shrinking land, intertidal, and subtidal zones, with important implications for resource availability and distribution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70160354','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70160354"><span>Tidal marsh susceptibility to <span class="hlt">sea-level</span> rise: importance of local-scale models</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Thorne, Karen M.; Buffington, Kevin J.; Elliott-Fisk, Deborah L.; Takekawa, John Y.</p> <p>2015-01-01</p> <p>Increasing concern over <span class="hlt">sea-level</span> rise impacts to coastal tidal marsh ecosystems has led to modeling efforts to anticipate outcomes for resource management decision making. Few studies on the Pacific coast of North America have modeled <span class="hlt">sea-level</span> rise marsh susceptibility at a scale relevant to local wildlife populations and plant communities. Here, we use a novel approach in developing an empirical <span class="hlt">sea-level</span> rise ecological response model that can be applied to key management questions. Calculated elevation change over 13 y for a 324-ha portion of San Pablo Bay National Wildlife Refuge, California, USA, was used to represent local accretion and subsidence processes. Next, we coupled detailed plant community and elevation surveys with <span class="hlt">measured</span> rates of inundation frequency to model marsh state changes to 2100. By grouping plant communities into low, mid, and high marsh habitats, we were able to assess wildlife species vulnerability and to better understand outcomes for habitat resiliency. Starting study-site conditions were comprised of 78% (253-ha) high marsh, 7% (30-ha) mid marsh, and 4% (18-ha) low marsh habitats, dominated by pickleweed Sarcocornia pacifica and cordgrass Spartina spp. Only under the low <span class="hlt">sea-level</span> rise scenario (44 cm by 2100) did our models show persistence of some marsh habitats to 2100, with the area dominated by low marsh habitats. Under mid (93 cm by 2100) and high <span class="hlt">sea-level</span> rise scenarios (166 cm by 2100), most mid and high marsh habitat was lost by 2070, with only 15% (65 ha) remaining, and a complete loss of these habitats by 2080. Low marsh habitat increased temporarily under all three <span class="hlt">sea-level</span> rise scenarios, with the peak (286 ha) in 2070, adding habitat for the endemic endangered California Ridgway’s rail Rallus obsoletus obsoletus. Under mid and high <span class="hlt">sea-level</span> rise scenarios, an almost complete conversion to mudflat occurred, with most of the area below mean <span class="hlt">sea</span> <span class="hlt">level</span>. Our modeling assumed no marsh migration upslope due to human</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26587269','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26587269"><span>Nest inundation from <span class="hlt">sea-level</span> rise threatens <span class="hlt">sea</span> turtle population viability.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pike, David A; Roznik, Elizabeth A; Bell, Ian</p> <p>2015-07-01</p> <p>Contemporary <span class="hlt">sea-level</span> rise will inundate coastal habitats with seawater more frequently, disrupting the life cycles of terrestrial fauna well before permanent habitat loss occurs. <span class="hlt">Sea</span> turtles are reliant on low-lying coastal habitats worldwide for nesting, where eggs buried in the sand remain vulnerable to inundation until hatching. We show that saltwater inundation directly lowers the viability of green turtle eggs (Chelonia mydas) collected from the world's largest green turtle nesting rookery at Raine Island, Australia, which is undergoing enigmatic decline. Inundation for 1 or 3 h reduced egg viability by less than 10%, whereas inundation for 6 h reduced viability by approximately 30%. All embryonic developmental stages were vulnerable to mortality from saltwater inundation. Although the hatchlings that emerged from inundated eggs displayed normal physical and behavioural traits, hypoxia during incubation could influence other aspects of the physiology or behaviour of developing embryos, such as learning or spatial orientation. Saltwater inundation can directly lower hatching success, but it does not completely explain the consistently low rates of hatchling production observed on Raine Island. More frequent nest inundation associated with <span class="hlt">sea-level</span> rise will increase variability in <span class="hlt">sea</span> turtle hatching success spatially and temporally, due to direct and indirect impacts of saltwater inundation on developing embryos.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70031023','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70031023"><span>Holocene <span class="hlt">sea</span> <span class="hlt">level</span> and climate change in the Black <span class="hlt">Sea</span>: Multiple marine incursions related to freshwater discharge events</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Martin, R.E.; Leorri, E.; McLaughlin, P.P.</p> <p>2007-01-01</p> <p>Repeated marine invasions of the Black <span class="hlt">Sea</span> during the Holocene have been inferred by many eastern scientists as resulting from episodes of marine inflow from the Mediterranean beneath a brackish outflow from the Black <span class="hlt">Sea</span>. We support this scenario but a fundamental question remains: What caused the repeated marine invasions? We offer an hypothesis for the repeated marine invasions of the Black <span class="hlt">Sea</span> based on: (1) the overall similarity of <span class="hlt">sea-level</span> curves from both tectonically quiescent and active margins of the Black <span class="hlt">Sea</span> and their similarity to a sequence stratigraphic record from the US mid-Atlantic coast. The similarity of the records from two widely-separated regions suggests their common response to documented Holocene climate ocean-atmosphere reorganizations (coolings); (2) the fact that in the modern Black <span class="hlt">Sea</span>, freshwater runoff from surrounding rivers dominates over evaporation, so that excess runoff might have temporarily raised Black <span class="hlt">Sea</span> <span class="hlt">level</span> (although the Black <span class="hlt">Sea</span> would have remained brackish). Following the initial invasion of the Black <span class="hlt">Sea</span> by marine Mediterranean waters (through the Marmara <span class="hlt">Sea</span>) in the early Holocene, repeated marine incursions were modulated, or perhaps even caused, by freshwater discharge to the Black <span class="hlt">Sea</span>. Climatic amelioration (warming) following each documented ocean-atmosphere reorganization during the Holocene likely shifted precipitation patterns in the surrounding region and caused mountain glaciers to retreat, increasing freshwater runoff above modern values and temporarily contributing to an increase of Black <span class="hlt">Sea</span> <span class="hlt">level</span>. Freshwater-to-brackish water discharges into the Black <span class="hlt">Sea</span> initially slowed marine inflow but upon mixing of runoff with more marine waters beneath them and their eventual exit through the Bosphorus, marine inflow increased again, accounting for the repeated marine invasions. The magnitude of the hydrologic and <span class="hlt">sea-level</span> fluctuations became increasingly attenuated through the Holocene, as reflected by Black</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005SedG..176...43E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005SedG..176...43E"><span>Controls on Precambrian <span class="hlt">sea</span> <span class="hlt">level</span> change and sedimentary cyclicity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Eriksson, P. G.; Catuneanu, O.; Nelson, D. R.; Popa, M.</p> <p>2005-04-01</p> <p>Although uniformitarianism applies in a general sense to the controls on relative and global <span class="hlt">sea</span> <span class="hlt">level</span> change, some influences thereon were more prominent in the Precambrian. Short-term base <span class="hlt">level</span> change due to waves and tides may have been enhanced due to possibly more uniform circulation systems on wide, low gradient Precambrian shelves. The lack of evidence for global glacial events in the Precambrian record implies that intraplate stresses and cyclic changes to Earth's geoid were more likely explanations for third-order <span class="hlt">sea</span> <span class="hlt">level</span> change than glacio-eustasy. Higher heat flow in the earlier Precambrian may have led to more rapid tectonic plate formation, transport and destruction, along with an increased role for hot spots, aseismic ridges and mantle plumes (superplumes), all of which may have influenced cyclic sedimentation within the ocean basins. A weak cyclicity in the occurrence of plume events has an approximate duration comparable to that of first-order (supercontinental cycle) <span class="hlt">sea</span> <span class="hlt">level</span> change. Second-order cyclicity in the Precambrian largely reflects the influences of thermal epeirogeny, changes to mid-ocean ridge volume as well as to ridge growth and decay rates, and cratonic marginal downwarping concomitant with either sediment loading or extensional tectonism. Third-order cycles of <span class="hlt">sea</span> <span class="hlt">level</span> change in the Precambrian also reflected cyclic loading/unloading within flexural foreland basin settings, and filling/deflation of magma chambers associated with island arc evolution. The relatively limited number of studies of Precambrian sequence stratigraphy allows some preliminary conclusions to be drawn on duration of the first three orders of cyclicity. Archaean greenstone basins appear to have had first- and second-order cycle durations analogous to Phanerozoic equivalents, supporting steady state tectonics throughout Earth history. In direct contrast, however, preserved basin-fills from Neoarchaean-Palaeoproterozoic cratonic terranes have first- and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMOS41A1175K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMOS41A1175K"><span>Air-<span class="hlt">Sea</span> Interaction <span class="hlt">Measurements</span> from the Controlled Towed Vehicle</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Khelif, D.; Bluth, R. T.; Jonsson, H.; Barge, J.</p> <p>2014-12-01</p> <p>The Controlled Towed Vehicle (CTV) uses improved towed drone technology to actively maintain via a radar altimeter and controllable wing a user-set height that can be as low as the canonical reference height of 10 m above the <span class="hlt">sea</span> surface. After take-off, the drone is released from the tow aircraft on a ~700-m stainless steel cable. We have instrumented the 0.23 m diameter and 2.13 m long drone with high fidelity instruments to <span class="hlt">measure</span> the means and turbulent fluctuations of 3-D wind vector, temperature, humidity, pressure, CO2 and IR <span class="hlt">sea</span> surface temperature. Data are recorded internally at 40 Hz and simultaneously transmitted to the tow aircraft via dedicated wireless Ethernet link. The CTV accommodates 40 kg of instrument payload and provides it with 250 W of continuous power through a ram air propeller-driven generator. Therefore its endurance is only limited by that of the tow aircraft.We will discuss the CTV development, the engineering challenges and solutions that have been successfully implemented to overcome them. We present results from recent flights as low as 9 m over the coastal ocean and comparisons of profiles and turbulent fluxes from the CTV and the tow aircraft. Manned aircraft operation at low-<span class="hlt">level</span> boundary-layer flights is very limited. Dropsondes and UAS (Unmanned Aerial Systems) and UAS are alternates for <span class="hlt">measurements</span> near the ocean surface. However, dropsondes have limited sensor capability and do not <span class="hlt">measure</span> fluxes, and most present UAS vehicles do not have the payload and power capacity nor the low-flying ability in high winds over the oceans. The CTV therefore, fills a needed gap between the dropsondes, in situ aircraft, and UAS. The payload, capacity and power of the CTV makes it suitable for a variety of atmospheric research <span class="hlt">measurements</span>. Other sensors to <span class="hlt">measure</span> aerosol, chemistry, radiation, etc., could be readily accommodated in the CTV.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001JGR...10613953L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001JGR...10613953L"><span>Current <span class="hlt">measurements</span> in the Maluku <span class="hlt">Sea</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Luick, John L.; Cresswell, George R.</p> <p>2001-07-01</p> <p>A current meter mooring was deployed in the eastern Indonesian archipelago, in the Maluku <span class="hlt">Sea</span>, between the islands of Sulawesi and Halmahera, to contribute to estimates of the volume of the Indonesian Throughflow, for 13 months (June 1993-July 1994), with meters located at 740, 1250, 1750, and 2240 m below the surface. Hydrocasts for salinity and temperature were made at the time of deployment. The current meter and hydrographic data indicate a predominantly southward flow at the upper three meters throughout the year and a steady northward flow at the bottom meter. T-S and oxygen properties below 1800 m indicate a clockwise circulation in the Maluku <span class="hlt">Sea</span>, with a vertical velocity of about 2 m/d. If the currents at the mooring, which is located on the western side of the Maluku <span class="hlt">Sea</span>, are typical of the entire basin width, the average southward through flow between 740 m and 1500 m below the surface, 7 Sv (1 Sv = 106 m3/s ), is comparable in magnitude with estimates of upper layer transport and should be accounted for in estimates of the Indonesian Throughflow.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.2158C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.2158C"><span>Bayesian Statistical Analysis of Historical and Late Holocene Rates of <span class="hlt">Sea-Level</span> Change</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cahill, Niamh; Parnell, Andrew; Kemp, Andrew; Horton, Benjamin</p> <p>2014-05-01</p> <p>A fundamental concern associated with climate change is the rate at which <span class="hlt">sea</span> <span class="hlt">levels</span> are rising. Studies of past <span class="hlt">sea</span> <span class="hlt">level</span> (particularly beyond the instrumental data range) allow modern <span class="hlt">sea-level</span> rise to be placed in a more complete context. Considering this, we perform a Bayesian statistical analysis on historical and late Holocene rates of <span class="hlt">sea-level</span> change. The data that form the input to the statistical model are tide-gauge <span class="hlt">measurements</span> and proxy reconstructions from cores of coastal sediment. The aims are to estimate rates of <span class="hlt">sea-level</span> rise, to determine when modern rates of <span class="hlt">sea-level</span> rise began and to observe how these rates have been changing over time. Many of the current methods for doing this use simple linear regression to estimate rates. This is often inappropriate as it is too rigid and it can ignore uncertainties that arise as part of the data collection exercise. This can lead to over confidence in the <span class="hlt">sea-level</span> trends being characterized. The proposed Bayesian model places a Gaussian process prior on the rate process (i.e. the process that determines how rates of <span class="hlt">sea-level</span> are changing over time). The likelihood of the observed data is the integral of this process. When dealing with proxy reconstructions, this is set in an errors-in-variables framework so as to take account of age uncertainty. It is also necessary, in this case, for the model to account for glacio-isostatic adjustment, which introduces a covariance between individual age and <span class="hlt">sea-level</span> observations. This method provides a flexible fit and it allows for the direct estimation of the rate process with full consideration of all sources of uncertainty. Analysis of tide-gauge datasets and proxy reconstructions in this way means that changing rates of <span class="hlt">sea</span> <span class="hlt">level</span> can be estimated more comprehensively and accurately than previously possible. The model captures the continuous and dynamic evolution of <span class="hlt">sea-level</span> change and results show that not only are modern <span class="hlt">sea</span> <span class="hlt">levels</span> rising but that the rates</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008PhDT.......110R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008PhDT.......110R"><span>Modeling future <span class="hlt">sea</span> <span class="hlt">level</span> rise from melting glaciers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Radic, Valentina</p> <p></p> <p>Melting mountain glaciers and ice caps (MG&IC) are the second largest contributor to rising <span class="hlt">sea</span> <span class="hlt">level</span> after thermal expansion of the oceans and are likely to remain the dominant glaciological contributor to rising <span class="hlt">sea</span> <span class="hlt">level</span> in the 21st century. The aim of this work is to project 21st century volume changes of all MG&IC and to provide systematic analysis of uncertainties originating from different sources in the calculation. I provide an ensemble of 21st century volume projections for all MG&IC from the World Glacier Inventory by modeling the surface mass balance coupled with volume-area-length scaling and forced with temperature and precipitation scenarios from four Global Climate Models (GCMs). By upscaling the volume projections through a regionally differentiated approach to all MG&IC outside Greenland and Antarctica (514,380 km 2) I estimated total volume loss for the time period 2001-2100 to range from 0.039 to 0.150 m <span class="hlt">sea</span> <span class="hlt">level</span> equivalent. While three GCMs agree that Alaskan glaciers are the main contributors to the projected <span class="hlt">sea</span> <span class="hlt">level</span> rise, one GCM projected the largest total volume loss mainly due to Arctic MG&IC. The uncertainties in the projections are addressed by a series of sensitivity tests applied in the methodology for assessment of global volume changes and on individual case studies for particular glaciers. Special emphasis is put on the uncertainties in volume-area scaling. For both, individual and global assessments of volume changes, the choice of GCM forcing glacier models is shown to be the largest source of quantified uncertainties in the projections. Another major source of uncertainty is the temperature forcing in the mass balance model depending on the quality of climate reanalysis products (ERA-40) in order to simulate the local temperatures on a mountain glacier or ice cap. Other uncertainties in the methods are associated with volume-area-length scaling as a tool for deriving glacier initial volumes and glacier geometry changes in the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMGC54B..04H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMGC54B..04H"><span>A new Holocene <span class="hlt">sea-level</span> database for the US Gulf Coast: Improving constraints for past and future <span class="hlt">sea</span> <span class="hlt">levels</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hijma, M.; Tornqvist, T. E.; Hu, P.; Gonzalez, J.; Hill, D. F.; Horton, B. P.; Engelhart, S. E.</p> <p>2011-12-01</p> <p>The interpretation of present-day <span class="hlt">sea-level</span> change, as well as the prediction of future relative <span class="hlt">sea-level</span> (RSL) rise and its spatial variability, depend increasingly on the ability of glacial isostatic adjustment (GIA) models to reveal non-eustatic components of RSL change. GIA results from the redistribution of mass due to the growth and decay of ice sheets. As a consequence, formerly ice-covered areas are still rebounding and currently experience RSL fall, while in other areas the rate of RSL rise is enhanced due to glacial forebulge collapse. The development of GIA models relies to a large extent on the availability of quality-controlled Holocene RSL data. There is thus an urgent need for systematically compiled and publicly available databases of geological RSL data that can be used not only for the purposes mentioned above, but also can serve to underpin coastal management and policy decisions. We have focused our efforts to develop a Holocene <span class="hlt">sea-level</span> database for the Atlantic and Gulf coasts of the US. Many of the research problems that can be addressed with this <span class="hlt">sea-level</span> database revolve around the identification of crustal motions due to glacial forebulge collapse that affects the entire region and likely extends beyond South Florida. For the east coast, GIA-related subsidence rates have been calculated with unprecedented precision: <0.8 mm a-1 in Maine, increasing to rates of 1.7 mm a-1 in Delaware, and a return to rates <0.9 mm a-1 in the Carolinas. Here, we first define our methodology to reconstruct RSL, with particular reference to the quantification of age and elevation errors. Many <span class="hlt">sea-level</span> indicators are related to a specific tide <span class="hlt">level</span> (e.g., peat that formed between highest astronomical tide and mean high water <span class="hlt">level</span>). We use paleotidal modeling to account for any changes during the Holocene. We furthermore highlight a number of errors associated with 14C dating that have rarely, if ever, been considered in previous studies of this nature</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMNH23C..03D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMNH23C..03D"><span><span class="hlt">Sea-Level</span> Rise for California, Oregon, and Washington: Present and Future</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dalrymple, R. A.</p> <p>2012-12-01</p> <p>This talk discusses the results of a NRC study on U.S. west coast <span class="hlt">sea-level</span> rise, completed in June. The first part of the study deals with global <span class="hlt">sea</span> <span class="hlt">level</span> rise, utilizing data generated since the IPCC (2007) report and examining each of the major contributors to <span class="hlt">sea-level</span> risel: thermal expansion of <span class="hlt">sea</span> water in response to a warming atmosphere and ice melt from glaciers, ice caps, and ice sheets. Results show that land ice melt is currently the largest contributor to <span class="hlt">sea</span> <span class="hlt">level</span> rise. Predictions of global <span class="hlt">sea</span> <span class="hlt">level</span> are developed for 2030, 2050, and 2100. Next, regional <span class="hlt">sea</span> <span class="hlt">level</span> is determined by including the effects of local vertical land motions, from tectonics, subsidence, and the spatial distribution of ice melt <span class="hlt">sea</span> <span class="hlt">level</span> contributions (<span class="hlt">sea</span> <span class="hlt">level</span> fingerprinting). Of particular interest is the potential of a Cascadia subduction zone earthquake that could add more than a meter of <span class="hlt">sea-level</span> rise in minutes in addition to the expected <span class="hlt">sea</span> <span class="hlt">level</span> rise. Again, predictions of <span class="hlt">sea-level</span> rise for the shoreline of the west coast for 2030, 2050, and 2100 are determined. Implications of <span class="hlt">sea</span> <span class="hlt">level</span> rise on storminess, and the erosion of beaches, coastal cliffs, and wetlands are discussed as well.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.C53B0774M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.C53B0774M"><span>Impact of Spatial Aliasing on <span class="hlt">Sea</span>-ice Thickness <span class="hlt">Measurements</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mueller, H. R.; Geiger, C. A.; Samluk, J. P.; Bernstein, E. R.; Richter-Menge, J.</p> <p>2015-12-01</p> <p>A frequency distribution of snow and <span class="hlt">sea</span> ice is generated by counting and then binning the number of thicknesses into contiguous intervals (typically in 10 cm bins). Because <span class="hlt">sea</span> ice is only meters thick but spans thousands of kilometers, these distributions serve as a "Rosetta Stone" to communicate proportions of thickness across scales - especially for characterizing deformation processes. Because the frequency distribution is such an important communication tool, we explore the impact of spatial aliasing on non-Gaussian distributions of snow and <span class="hlt">sea</span> ice thickness. Using a heuristic model and >1000 in situ <span class="hlt">measurements</span>, we show how different instrument footprint sizes and shapes can cluster thickness distributions into artificial modes, thereby distorting frequency distributions and making it difficult to compare and communicate information across spatial scales. This problem has not been dealt with systematically for <span class="hlt">sea</span> ice until now, largely because it appears to incur no significant change in integrated thickness, which often serves as a volume proxy. The problem is of second order at any one scale but becomes a first order problem for non-Gaussian distributions when data are collected at different scales. We quantify the impact of spatial aliasing by computing resolution error (Er) over a range of horizontal scales (x) from 5 to 500 m. Results are summarized through a power law (Er=bxm) with distinct exponents (m) from 0.3 to 0.5 using example mathematical functions including Gaussian, inverse linear, and running mean filters. The most important finding is that a running mean filter introduces a great deal of aliasing and should be avoided whenever possible. A simple and effective substitute for the running mean is an inverse linear filter which is commonly used in numerical model data interpolation. In this study, inverse linear filters were as effective as a Gaussian filter in terms of minimizing aliasing. There is much to be gained at the community <span class="hlt">level</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/circ/1392/pdf/circ1392.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/circ/1392/pdf/circ1392.pdf"><span>Land subsidence and relative <span class="hlt">sea-level</span> rise in the southern Chesapeake Bay region</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Eggleston, Jack; Pope, Jason</p> <p>2013-01-01</p> <p>The southern Chesapeake Bay region is experiencing land subsidence and rising water <span class="hlt">levels</span> due to global <span class="hlt">sea-level</span> rise; land subsidence and rising water <span class="hlt">levels</span> combine to cause relative <span class="hlt">sea-level</span> rise. Land subsidence has been observed since the 1940s in the southern Chesapeake Bay region at rates of 1.1 to 4.8 millimeters per year (mm/yr), and subsidence continues today. This land subsidence helps explain why the region has the highest rates of <span class="hlt">sea-level</span> rise on the Atlantic Coast of the United States. Data indicate that land subsidence has been responsible for more than half the relative <span class="hlt">sea-level</span> rise <span class="hlt">measured</span> in the region. Land subsidence increases the risk of flooding in low-lying areas, which in turn has important economic, environmental, and human health consequences for the heavily populated and ecologically important southern Chesapeake Bay region. The aquifer system in the region has been compacted by extensive groundwater pumping in the region at rates of 1.5- to 3.7-mm/yr; this compaction accounts for more than half of observed land subsidence in the region. Glacial isostatic adjustment, or the flexing of the Earth’s crust in response to glacier formation and melting, also likely contributes to land subsidence in the region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9645E..0HN','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9645E..0HN"><span>A comparison and evaluation between ICESat/GLAS altimetry and mean <span class="hlt">sea</span> <span class="hlt">level</span> in Thailand</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Naksen, Didsaphan; Yang, Dong Kai</p> <p>2015-10-01</p> <p>Surface elevation is one of the importance information for GIS. Usually surface elevation can acquired from many sources such as satellite imageries, aerial photograph, SAR data or LiDAR by photogrammetry, remote sensing methodology. However the most trust information describe the actual surface elevation is <span class="hlt">Leveling</span> from terrestrial survey. <span class="hlt">Leveling</span> is giving the highest accuracy but in the other hand is also long period process spending a lot of budget and resources, moreover the LiDAR technology is new era to <span class="hlt">measure</span> surface elevation. ICESat/GLAS is spaceborne LiDAR platform, a scientific satellite lunched by NASA in 2003. The study area was located at the middle part of Thailand between 12. ° - 14° North and 98° -100° East Latitude and Longitude. The main idea is to compare and evaluate about elevation between ICESat/GLAS Altimetry and mean <span class="hlt">sea</span> <span class="hlt">level</span> of Thailand. Data are collected from various sources, including the ICESat/GLAS altimetry data product from NASA, mean <span class="hlt">sea</span> <span class="hlt">level</span> from Royal Thai Survey Department (RTSD). For methodology, is to transform ICESat GLA14 from TOPX/Poseidon-Jason ellipsoid to WGS84 ellipsoid. In addition, ICESat/GLAS altimetry that extracted form centroid of laser footprint and mean <span class="hlt">sea</span> <span class="hlt">level</span> were compared and evaluated by 1st Layer National Vertical Reference Network. The result is shown that generally the range of elevation between ICESat/GLAS and mean <span class="hlt">sea</span> <span class="hlt">level</span> is wildly from 0. 8 to 25 meters in study area.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22318519','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22318519"><span>Recent contributions of glaciers and ice caps to <span class="hlt">sea</span> <span class="hlt">level</span> rise.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jacob, Thomas; Wahr, John; Pfeffer, W Tad; Swenson, Sean</p> <p>2012-02-08</p> <p>Glaciers and ice caps (GICs) are important contributors to present-day global mean <span class="hlt">sea</span> <span class="hlt">level</span> rise. Most previous global mass balance estimates for GICs rely on extrapolation of sparse mass balance <span class="hlt">measurements</span> representing only a small fraction of the GIC area, leaving their overall contribution to <span class="hlt">sea</span> <span class="hlt">level</span> rise unclear. Here we show that GICs, excluding the Greenland and Antarctic peripheral GICs, lost mass at a rate of 148 ± 30 Gt yr(-1) from January 2003 to December 2010, contributing 0.41 ± 0.08 mm yr(-1) to <span class="hlt">sea</span> <span class="hlt">level</span> rise. Our results are based on a global, simultaneous inversion of monthly GRACE-derived satellite gravity fields, from which we calculate the mass change over all ice-covered regions greater in area than 100 km(2). The GIC rate for 2003-2010 is about 30 per cent smaller than the previous mass balance estimate that most closely matches our study period. The high mountains of Asia, in particular, show a mass loss of only 4 ± 20 Gt yr(-1) for 2003-2010, compared with 47-55 Gt yr(-1) in previously published estimates. For completeness, we also estimate that the Greenland and Antarctic ice sheets, including their peripheral GICs, contributed 1.06 ± 0.19 mm yr(-1) to <span class="hlt">sea</span> <span class="hlt">level</span> rise over the same time period. The total contribution to <span class="hlt">sea</span> <span class="hlt">level</span> rise from all ice-covered regions is thus 1.48 ± 0.26 mm (-1), which agrees well with independent estimates of <span class="hlt">sea</span> <span class="hlt">level</span> rise originating from land ice loss and other terrestrial sources.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006OcDyn..56..487W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006OcDyn..56..487W"><span>Brest <span class="hlt">sea</span> <span class="hlt">level</span> record: a time series construction back to the early eighteenth century</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wöppelmann, Guy; Pouvreau, Nicolas; Simon, Bernard</p> <p>2006-12-01</p> <p>The completeness and the accuracy of the Brest <span class="hlt">sea</span> <span class="hlt">level</span> time series dating from 1807 make it suitable for long-term <span class="hlt">sea</span> <span class="hlt">level</span> trend studies. New data sets were recently discovered in the form of handwritten tabulations, including several decades of the eighteenth century. <span class="hlt">Sea</span> <span class="hlt">level</span> observations have been made in Brest since 1679. This paper presents the historical data sets which have been assembled so far. These data sets span approximately 300 years and together constitute the longest, near-continuous set of <span class="hlt">sea</span> <span class="hlt">level</span> information in France. However, an important question arises: Can we relate the past and the present-day records? We partially provide an answer to this question by analysing the documents of several historical libraries with the tidal data using a ‘data archaeology’ approach advocated by Woodworth ( Geophys Res Lett 26:1589 1592, 1999b). A second question arises concerning the accuracy of such records. Careful editing was undertaken by examining the residuals between tidal predictions and observations. It proved useful to remove the worst effects of timing errors, in particular the sundial correction to be applied prior to August 1, 1714. A refined correction based on sundial literature [Savoie, La gnomique, Editions Les Belles Lettres, Paris, 2001] is proposed, which eliminates the systematic offsets seen in the discrepancies in timing of the <span class="hlt">sea</span> <span class="hlt">level</span> <span class="hlt">measurements</span>. The tidal analysis has also shown that shallow-water tidal harmonics at Brest causes a systematic difference of 0.023 m between mean <span class="hlt">sea</span> <span class="hlt">level</span> (MSL) and mean tide <span class="hlt">level</span> (MTL). Thus, MTL should not be mixed with the time series of MSL because of this systematic offset. The study of the trends in MTL and MSL however indicates that MTL can be used as a proxy for MSL. Three linear trend periods are distinguished in the Brest MTL time series over the period 1807 2004. Our results support the recent findings of Holgate and Woodworth ( Geophys Res Lett) of an enhanced coastal <span class="hlt">sea</span> <span class="hlt">level</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020017580','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020017580"><span>X-33 XRS-2200 Linear Aerospike Engine <span class="hlt">Sea</span> <span class="hlt">Level</span> Plume Radiation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>DAgostino, Mark G.; Lee, Young C.; Wang, Ten-See; Turner, Jim (Technical Monitor)</p> <p>2001-01-01</p> <p>Wide band plume radiation data were collected during ten <span class="hlt">sea</span> <span class="hlt">level</span> tests of a single XRS-2200 engine at the NASA Stennis Space Center in 1999 and 2000. The XRS-2200 is a liquid hydrogen/liquid oxygen fueled, gas generator cycle linear aerospike engine which develops 204,420 lbf thrust at <span class="hlt">sea</span> <span class="hlt">level</span>. Instrumentation consisted of six hemispherical radiometers and one narrow view radiometer. Test conditions varied from 100% to 57% power <span class="hlt">level</span> (PL) and 6.0 to 4.5 oxidizer to fuel (O/F) ratio. <span class="hlt">Measured</span> radiation rates generally increased with engine chamber pressure and mixture ratio. One hundred percent power <span class="hlt">level</span> radiation data were compared to predictions made with the FDNS and GASRAD codes. Predicted <span class="hlt">levels</span> ranged from 42% over to 7% under average test values.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6645326','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6645326"><span>Correlation of <span class="hlt">sea</span> <span class="hlt">level</span> falls interpreted from atoll stratigraphy with turbidites in adjacent basins</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lincoln, J.M. )</p> <p>1990-05-01</p> <p>Past <span class="hlt">sea</span> <span class="hlt">levels</span> can be derived from any atoll subsurface sediments deposited at or near <span class="hlt">sea</span> <span class="hlt">level</span> by determining the ages of deposition and correcting the present depths to the sediments for subsidence of the underlying edifice since the times of deposition. A <span class="hlt">sea</span> <span class="hlt">level</span> curve constructed by this method consists of discontinuous segments, each corresponding to a period of rising relative <span class="hlt">sea</span> <span class="hlt">level</span> and deposition of a discrete sedimentary package. Discontinuities in the <span class="hlt">sea</span> <span class="hlt">level</span> curve derived by this method correspond to relative <span class="hlt">sea</span> <span class="hlt">level</span> falls and stratigraphic hiatuses in the atoll subsurface. During intervals of relative <span class="hlt">sea</span> <span class="hlt">level</span> fall an atoll emerges to become a high limestone island. <span class="hlt">Sea</span> <span class="hlt">level</span> may fluctuate several times during a period of atoll emergence to become a high limestone island. <span class="hlt">Sea</span> <span class="hlt">level</span> may fluctuate several times during a period of atoll emergence without depositing sediments on top of the atoll. Furthermore, subaerial erosion may remove a substantial part of the depositional record of previous <span class="hlt">sea</span> <span class="hlt">level</span> fluctuations. For these reasons the authors must look to the adjacent basins to complement the incomplete record of <span class="hlt">sea</span> <span class="hlt">level</span> change recorded beneath atolls. During lowstands of <span class="hlt">sea</span> <span class="hlt">level</span>, faunas originally deposited near <span class="hlt">sea</span> <span class="hlt">level</span> on an atoll may be eroded and redeposited as turbidites in deep adjacent basins. Three such turbidites penetrated during deep-<span class="hlt">sea</span> drilling at Sites 462 and 315 in the central Pacific correlate well with a late Tertiary <span class="hlt">sea</span> <span class="hlt">level</span> curve based on biostratigraphic ages and {sup 87}Sr/{sup 86}Sr chronostratigraphy for core from Enewetak Atoll in the northern Marshall Islands. Further drilling of the archipelagic aprons adjacent to atolls will improve the <span class="hlt">sea</span> <span class="hlt">level</span> history that may be inferred from atoll stratigraphy.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.9669R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.9669R"><span><span class="hlt">Sea</span> <span class="hlt">level</span> and current validation for an early warning coastal system on the Catalan coast (NW Mediterranean <span class="hlt">Sea</span>)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ràfols, Laura; abdelmalik, Sairouni; Bravo, Manel; Espino, Manuel; Grifoll, Manel</p> <p>2015-04-01</p> <p>An early warning coastal system is being implemented on the Catalan coast (North-western Mediterranean <span class="hlt">Sea</span>) in order to provide high resolution forecast of <span class="hlt">sea</span> <span class="hlt">levels</span>, current velocities and wave conditions. The present investigation is focused on the oceanic model, which provides information about <span class="hlt">sea</span> <span class="hlt">level</span> and currents. The aim of this study is to validate the <span class="hlt">sea</span> <span class="hlt">level</span> and current forecasts obtained with the help of the Regional Ocean Model System (ROMS; Shchepetkin and McWilliams, 2005) in a high resolution domain (350 metres). In an attempt to reduce the high computational cost required for such a small grid, the Catalan coast has been divided into a few separate domains, which are run independently of each other. For the initial and boundary conditions, data from the MyOcean-IBI products have been used and the atmospheric forcing fields have been obtained from the Catalan Meteorological Service (SMC) and the Spanish Meteorological Agency (AEMET). For a validation purpose, different study periods have been taken into account. Then, the validation of the model has been done using the available in-situ tide-gauge and buoy <span class="hlt">measurements</span> and HF satellite data. During energetic events, the interaction between currents and waves is expected to be relevant in the shallower areas. For this reason, a coupled wave-ocean system has been implemented to investigate the improvements in the forecasts when faced with the results of separated simulations. In this case, the ROMS model and the SWAN model (Simulating WAves Nearshore; Booij et al., 1999) have been run as part of the Coupled Ocean-Atmosphere-Wave-Sediment Transport (COAWST) Modeling System (Warner et al., 2010), which uses the Model Coupling Toolkit to exchange data fields between the models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1614722L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1614722L"><span>Multi-system, multi-signal GNSS-reflectometry for <span class="hlt">sea</span> <span class="hlt">level</span> observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Löfgren, Johan; Haas, Rüdiger</p> <p>2014-05-01</p> <p>-to-Noise Ratio (SNR) data observed with the zenith-looking antenna/receiver to determine the distance between the <span class="hlt">sea</span> surface and the antenna. The different approaches have advantages and disadvantages, and they can be combined with standard positioning of the zenith-looking antenna to give absolute <span class="hlt">sea</span> <span class="hlt">level</span> information. In the presentation we describe the installation, the analysis methods and present the corresponding results. The focus is in particular on GPS and GLONASS observations in both L-band frequency bands, and the result obtained are from the different analysis approaches are compared with independently derived <span class="hlt">sea</span> <span class="hlt">level</span> observations from a co-located traditional tide gauge. Our results show that GPS and GLONASS phase-delay analysis method using signals in the L1 and L2 frequency bands gives a root-mean-square (RMS) agreement on the order of 3-4 cm when compared to independently observed <span class="hlt">sea</span> <span class="hlt">level</span> data. The corresponding results derived from the SNR-analysis method are worse by a factor of about 1.5 and 3 for the L1 and L2 frequency bands, respectively. However, the SNR-method appears to have advantages in conditions of high <span class="hlt">sea</span> surface roughness. References: Löfgren J, Haas R, Scherneck H-G, Bos M (2011) Three months of local <span class="hlt">sea</span> <span class="hlt">level</span> derived from reflected GNSS signals. Radio Science, 46 (RS0C05) Larson K, Löfgren J, Haas R (2013) Coastal <span class="hlt">Sea</span> <span class="hlt">Level</span> <span class="hlt">Measurements</span> Using a Single Geodetic GPS Receiver. Advances in Space Research, 51 (8) pp. 1301-1310.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.7043S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.7043S"><span><span class="hlt">Sea</span> <span class="hlt">level</span> rise of semi-enclosed basins: deviation of Adriatic and Baltic <span class="hlt">sea</span> <span class="hlt">level</span> from the mean global value.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Scarascia, Luca; Lionello, Piero</p> <p>2015-04-01</p> <p>Future <span class="hlt">sea</span> <span class="hlt">level</span> rise (SL), which represents today one of the major threats that are caused by climate change, will not be uniform. Regional differences are crucial for 40% of the world population, which is located in the coastal zone. To explore the mechanisms linking regional SL to climate variables is very important in order to provide reliable future projections. This study focuses on two semi-enclosed basins, the Adriatic and Baltic <span class="hlt">Sea</span> and investigates the deviation of their SL from the mean global value. In fact, past deviations of the SL of these two basins from the global value have been observed and can be attributed to large scale factors (such as teleconnections) and regional factors, such as the inverse barometric effect, the wind stress, the thermosteric and halosteric effects. The final goal of this work is to assess to which extent the Adriatic and Baltic SL will depart from the mean global value in the next decades and at the end of 21st century. This is achieved by analyzing deviations of the mean SL of the Baltic and Adriatic <span class="hlt">Sea</span> from the global mean SL during the 20th century and investigating which factors can explain such deviations. A multivariate linear regression model is built and used to describe the link between three large scale climate variables which are used as predictors (mean <span class="hlt">sea</span> <span class="hlt">level</span> pressure, surface air temperature and precipitation), and the regional SL deviation (the predictand), computed as the difference between the regional and the global SL. At monthly scale this linear regression model provides a good reconstruction of the past variability in the cold season during which it explains 60%-70% of the variance. Summer reconstruction is substantially less successful and it represents presently the main limit of the model skill. This linear regression model, forced by predictors extracted from CMIP5 multi-model simulations, is used to provide projections of SL in the Adriatic and Baltic <span class="hlt">Sea</span>. On the basis of the projections</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70136294','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70136294"><span>Estimating relative <span class="hlt">sea-level</span> rise and submergence potential at a coastal wetland</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Cahoon, Donald R.</p> <p>2015-01-01</p> <p>A tide gauge records a combined signal of the vertical change (positive or negative) in the <span class="hlt">level</span> of both the <span class="hlt">sea</span> and the land to which the gauge is affixed; or relative <span class="hlt">sea-level</span> change, which is typically referred to as relative <span class="hlt">sea-level</span> rise (RSLR). Complicating this situation, coastal wetlands exhibit dynamic surface elevation change (both positive and negative), as revealed by surface elevation table (SET) <span class="hlt">measurements</span>, that is not recorded at tide gauges. Because the usefulness of RSLR is in the ability to tie the change in <span class="hlt">sea</span> <span class="hlt">level</span> to the local topography, it is important that RSLR be calculated at a wetland that reflects these local dynamic surface elevation changes in order to better estimate wetland submergence potential. A rationale is described for calculating wetland RSLR (RSLRwet) by subtracting the SET wetland elevation change from the tide gauge RSLR. The calculation is possible because the SET and tide gauge independently <span class="hlt">measure</span> vertical land motion in different portions of the substrate. For 89 wetlands where RSLRwet was evaluated, wetland elevation change differed significantly from zero for 80 % of them, indicating that RSLRwet at these wetlands differed from the local tide gauge RSLR. When compared to tide gauge RSLR, about 39 % of wetlands experienced an elevation rate surplus and 58 % an elevation rate deficit (i.e., <span class="hlt">sea</span> <span class="hlt">level</span> becoming lower and higher, respectively, relative to the wetland surface). These proportions were consistent across saltmarsh, mangrove, and freshwater wetland types. Comparison of wetland elevation change and RSLR is confounded by high <span class="hlt">levels</span> of temporal and spatial variability, and would be improved by co-locating tide gauge and SET stations near each other and obtaining long-term records for both.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.T23C2284E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.T23C2284E"><span>Magnetotelluric <span class="hlt">Measurements</span> in the Alboran <span class="hlt">Sea</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Evans, R. L.; Jegen, M. D.; Garcia, X. A.; Matsuno, T.; Elsenbeck, J.; Worzewski, T. W.</p> <p>2010-12-01</p> <p>The PICASSO program aims to understand the tectonic history of the western Mediterranean, between Spain and Morocco, where conflicting models have suggested that the region is either a relict subduction system or a zone of mantle delamination. As part of this program we successfully deployed 12 seafloor MT instruments in water depths greater than 800m in the Alboran <span class="hlt">sea</span>. We plan to deploy additional instruments in the fall of 2010. An initial analysis of the data shows complex MT response functions with strong distortion due to seafloor topography and coast effect. This coast effect suggests a fairly resistive lithosphere beneath the seafloor, which is confirmed after inspection of the preliminary responses. We will present the data collected thus far, along with preliminary models of the profiles collected.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001JGR...10613945C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001JGR...10613945C"><span>Current <span class="hlt">measurements</span> in the Halmahera <span class="hlt">Sea</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cresswell, George R.; Luick, John L.</p> <p>2001-07-01</p> <p>A mooring with current meters at 400, 700, and 900 m at the 950-m isobath south of the 700-m-deep sill across the Halmahera <span class="hlt">Sea</span> revealed many signals between June 1993 and July 1994. Strong tidal currents of 50 cm/s dragged the mooring down by as much as 80 m on occasions when the lunar perigees corresponded with new or full moons. At 400 m the nontidal currents were southward at up 25 cm/s from October to April and northwestward at up to 20 cm/s at other times. At 700-m depth there was a near-continuous nontidal southward flow of 9 cm/s across the sill into the Halmahera Basin, which accords with findings by earlier Dutch and Indonesian workers. The current meter at 900-m depth showed the nontidal flow to be weak (~1 cm/s) to the west. The southward transport between 350 and 700 m was inferred to reach a maximum of 5 Sv during the NW monsoon, with the annual mean being 1.5 Sv. There was a spring-neap effect on the nontidal currents at 400 m that was most pronounced in the last few months of the mooring's life: these currents changed from ~10 cm/s to the east during neap tides to ~20 cm/s to the NNW during spring tides. Temperature and salinity profiles suggest that the waters of the Halmahera <span class="hlt">Sea</span> are derived in part from the New Guinea Coastal Undercurrent.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3789407','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3789407"><span>First biological <span class="hlt">measurements</span> of deep-<span class="hlt">sea</span> corals from the Red <span class="hlt">Sea</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Roder, C.; Berumen, M. L.; Bouwmeester, J.; Papathanassiou, E.; Al-Suwailem, A.; Voolstra, C. R.</p> <p>2013-01-01</p> <p>It is usually assumed that metabolic constraints restrict deep-<span class="hlt">sea</span> corals to cold-water habitats, with ‘deep-sea’ and ‘cold-water’ corals often used as synonymous. Here we report on the first <span class="hlt">measurements</span> of biological characters of deep-<span class="hlt">sea</span> corals from the central Red <span class="hlt">Sea</span>, where they occur at temperatures exceeding 20°C in highly oligotrophic and oxygen-limited waters. Low respiration rates, low calcification rates, and minimized tissue cover indicate that a reduced metabolism is one of the key adaptations to prevailing environmental conditions. We investigated four sites and encountered six species of which at least two appear to be undescribed. One species is previously reported from the Red <span class="hlt">Sea</span> but occurs in deep cold waters outside the Red <span class="hlt">Sea</span> raising interesting questions about presumed environmental constraints for other deep-<span class="hlt">sea</span> corals. Our findings suggest that the present understanding of deep-<span class="hlt">sea</span> coral persistence and resilience needs to be revisited. PMID:24091830</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..1410078H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..1410078H"><span>The Semiannual Oscillation of Southern Ocean <span class="hlt">Sea</span> <span class="hlt">Level</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hibbert, A.</p> <p>2012-04-01</p> <p>The atmospheric Semiannual Oscillation (SAO) is a half-yearly wave in mean <span class="hlt">sea</span> <span class="hlt">level</span> air pressure, which exhibits equinoctial maxima between 45°S and 50°S and solstitial maxima between 55°S and 65°s, with a phase reversal occurring at around 60°S. Its existence has been attributed to a phase difference in the annual temperature cycle between mid- and high-latitudes which sets up meridional temperature and pressure gradients that are largest during September and March, enhancing atmospheric baroclinicity and inducing equinoctial maxima in the Southern Hemisphere Westerlies. In this study, we use harmonic analysis of atmospheric and oceanic Southern Ocean datasets to show that this atmospheric SAO induces oceanic counterparts in <span class="hlt">sea</span> <span class="hlt">level</span> and circumpolar transport. This aspect of atmosphere-ocean interaction is particularly important, given the capacity of the Antarctic Circumpolar Current (ACC) to influence regional climate through the exchange of heat, fresh water and nutrients to each of the major ocean basins. We examine the relative contributions of local and regional semiannual atmospheric fluctuations in explaining the observed <span class="hlt">sea</span> <span class="hlt">level</span> response at 20 Southern Ocean and South Atlantic tide gauge stations and find that the oceanic SAO is associated with a modulation of zonal surface wind strength at key latitudes between ~55°S and 65°S. We also explore whether a seasonal inequality in SAO amplitude might facilitate the deduction of the timescales upon which Southern Ocean 'eddy saturation' theory might operate. However, though we find evidence of biannual fluctuations in eddy kinetic energy, regional variations in the phases and amplitudes of these emergent harmonics prevent us from elucidating the possible timescales upon which an eddy response to the atmospheric SAO might arise.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017QSRv..155...13K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017QSRv..155...13K"><span>Drivers of Holocene <span class="hlt">sea-level</span> change in the Caribbean</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Khan, Nicole S.; Ashe, Erica; Horton, Benjamin P.; Dutton, Andrea; Kopp, Robert E.; Brocard, Gilles; Engelhart, Simon E.; Hill, David F.; Peltier, W. R.; Vane, Christopher H.; Scatena, Fred N.</p> <p>2017-01-01</p> <p>We present a Holocene relative <span class="hlt">sea-level</span> (RSL) database for the Caribbean region (5°N to 25°N and 55°W to 90°W) that consists of 499 <span class="hlt">sea-level</span> index points and 238 limiting dates. The database was compiled from multiple <span class="hlt">sea-level</span> indicators (mangrove peat, microbial mats, beach rock and acroporid and massive corals). We subdivided the database into 20 regions to investigate the influence of tectonics and glacial isostatic adjustment on RSL. We account for the local-scale processes of sediment compaction and tidal range change using the stratigraphic position (overburden thickness) of index points and paleotidal modeling, respectively. We use a spatio-temporal empirical hierarchical model to estimate RSL position and its rates of change in the Caribbean over 1-ka time slices. Because of meltwater input, the rates of RSL change were highest during the early Holocene, with a maximum of 10.9 ± 0.6 m/ka in Suriname and Guyana and minimum of 7.4 ± 0.7 m/ka in south Florida from 12 to 8 ka. Following complete deglaciation of the Laurentide Ice Sheet (LIS) by ∼7 ka, mid-to late-Holocene rates slowed to < 2.4 ± 0.4 m/ka. The hierarchical model constrains the spatial extent of the mid-Holocene highstand. RSL did not exceed the present height during the Holocene, except on the northern coast of South America, where in Suriname and Guyana, RSL attained a height higher than present by 6.6 ka (82% probability). The highstand reached a maximum elevation of +1.0 ± 1.1 m between 5.3 and 5.2 ka. Regions with a highstand were located furthest away from the former LIS, where the effects from ocean syphoning and hydro-isostasy outweigh the influence of subsidence from forebulge collapse.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009GGG....1012003B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009GGG....1012003B"><span>Alkenones, alkenoates, and organic matter in coastal environments of NW Scotland: Assessment of potential application for <span class="hlt">sea</span> <span class="hlt">level</span> reconstruction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bendle, James A. P.; Rosell-Melé, Antoni; Cox, Nicholas J.; Shennan, Ian</p> <p>2009-12-01</p> <p>Reconstruction of late Quaternary <span class="hlt">sea</span> <span class="hlt">level</span> history in areas of glacioisostatic uplift often relies on sediment archives from coastal isolation basins, natural coastal rock depressions previously isolated from or connected to the <span class="hlt">sea</span> at different times. Proxy indicators for marine, brackish, or lacustrine conditions combined with precise dating can constrain the time when the <span class="hlt">sea</span> crossed the sill threshold and isolated (or connected) the basin. The utility of isolation basins in investigations of <span class="hlt">sea</span> <span class="hlt">level</span> change is well known, but investigations have been mostly limited to microfossil proxies, the application of which can be limited by preservation and nonanalog problems. Here we investigate the potential of long-chain alkenones, alkenoates, and bulk organic parameters (TOC, Corg/N) for reconstructing past <span class="hlt">sea</span> <span class="hlt">level</span> changes in isolation basins in NW Scotland. We analyze organic biomarkers and bulk parameters from both modern basins (at different stages of isolation from the <span class="hlt">sea</span>) and fossil basins (with <span class="hlt">sea</span> <span class="hlt">level</span> histories reconstructed from established proxies). Logit regression analysis was employed to find which of the biomarker metrics or bulk organic <span class="hlt">measurements</span> could reliably characterize the sediment samples in terms of a marine/brackish or isolated/lacustrine origin. The results suggested a good efficiency for the alkenone index %C37:4 at predicting the depositional origin of the sediments. This study suggests that alkenones could be used as a novel proxy for <span class="hlt">sea</span> <span class="hlt">level</span> change in fossil isolation basins especially when microfossil preservation is poor.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1986QuRes..26....3D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1986QuRes..26....3D"><span>Global ice-sheet system interlocked by <span class="hlt">sea</span> <span class="hlt">level</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Denton, George H.; Hughes, Terence J.; Karlén, Wibjörn</p> <p>1986-07-01</p> <p>Denton and Hughes (1983, Quaternary Research20, 125-144) postulated that <span class="hlt">sea</span> <span class="hlt">level</span> linked a global ice-sheet system with both terrestrial and grounded marine components during late Quaternary ice ages. Summer temperature changes near Northern Hemisphere melting margins initiated <span class="hlt">sea-level</span> fluctuations that controlled marine components in both polar hemispheres. It was further proposed that variations of this ice-sheet system amplified and transmitted Milankovitch summer half-year insolation changes between 45 and 75°N into global climatic changes. New tests of this hypothesis implicate <span class="hlt">sea</span> <span class="hlt">level</span> as a major control of the areal extent of grounded portions of the Antarctic Ice Sheet, thus fitting the concept of a globally interlocked ice-sheet system. But recent atmospheric modeling results ( Manabe and Broccoli, 1985, Journal of Geophysical Research90, 2167-2190) suggest that factors other than areal changes of the grounded Antarctic Ice Sheet strongly influenced Southern Hemisphere climate and terminated the last ice age simultaneously in both polar hemispheres. Atmospheric carbon dioxide linked to high-latitude oceans is the most likely candidate ( Shackleton and Pisias, 1985, Atmospheric carbon dioxide, orbital forcing, and climate. In "The Carbon Cycle and Atmospheric CO 2: Natural Variations Archean to Present" (E. T. Sundquest and W. S. Broecker, Eds.), pp. 303-318. Geophysical Monograph 32, American Geophysical Union, Washington, D.C.), but another potential influence was high-frequency climatic oscillations (2500 yr). It is postulated that variations in atmospheric carbon dioxide acted through an Antarctic ice shelf linked to the grounded ice sheet to produce and terminate Southern Hemisphere ice-age climate. It is further postulated that Milankovitch summer insolation combined with a warm high-frequency oscillation caused marked recession of Northern Hemisphere ice-sheet melting margins and the North Atlantic polar front about 14,000 14C yr B.P. This</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA560458','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA560458"><span>Nearshore <span class="hlt">Sea</span> Clutter <span class="hlt">Measurements</span> from a Fixed Platform</span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>2012-04-01</p> <p>1 1 Figure 1 1 . Downrange profile history ...for a sample multipath run . ...................................... 1 2 Figure 1 2. (a) Unwrapped downrange profile history (DRPH). (b) Unwrapped...were in 6 min increments. The anemometer was located approximately 20 m above mean <span class="hlt">sea</span> <span class="hlt">level</span>. Tidal water <span class="hlt">level</span> was referenced to the Mean Lower Low</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2012/1025/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2012/1025/"><span>Preliminary investigation of the effects of <span class="hlt">sea-level</span> rise on groundwater <span class="hlt">levels</span> in New Haven, Connecticut</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Bjerklie, David M.; Mullaney, John R.; Stone, Janet R.; Skinner, Brian J.; Ramlow, Matthew A.</p> <p>2012-01-01</p> <p>. Approaches to improve simulations include but are not limited to incorporating: * The variable density of seawater into the model in order to understand the current and future location of the interface between freshwater and saltwater; * Collection of additional data in order to better resolve temporal and spatial patterns in water <span class="hlt">levels</span> in the aquifer; * Improved estimates of recharge through direct and indirect <span class="hlt">measurements</span> of freshwater discharge from the study area; and * Transient simulations for greater understanding of the amount of time required for water <span class="hlt">levels</span> and the position of the interface between freshwater and saltwater to adjust to changes in <span class="hlt">sea</span> <span class="hlt">level</span> and recharge.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10105080','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10105080"><span>The validation of ATSR <span class="hlt">measurements</span> with in situ <span class="hlt">sea</span> temperatures</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Minnett, P.J.; Stansfield, K.L.</p> <p>1993-10-08</p> <p>The largest source of uncertainty in the retrieval of SST (<span class="hlt">sea</span>-surface) temperature from space-borne infrared radiometric <span class="hlt">measurements</span> is in the correction for the effects of the intervening atmosphere. During a research cruise of the R/V Alliance <span class="hlt">measurements</span> of <span class="hlt">sea</span> surface temperature, surface meteorological variables and surface infrared radiances were taken. SST fields were generated from the ATSR data using pre-launch algorithims derived by the ATSR Instrument Team (A.M. Zavody, personal communication), and the initial comparison between ATSR <span class="hlt">measurements</span> and SST taken along the ship`s track indicate that the dual-angle atmospheric correction is accurate in mid-latitude conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015NatCC...5..167S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015NatCC...5..167S"><span>Responding to rising <span class="hlt">sea</span> <span class="hlt">levels</span> in the Mekong Delta</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Smajgl, A.; Toan, T. Q.; Nhan, D. K.; Ward, J.; Trung, N. H.; Tri, L. Q.; Tri, V. P. D.; Vu, P. T.</p> <p>2015-02-01</p> <p>Vietnamese communities in the Mekong Delta are faced with the substantial impacts of rising <span class="hlt">sea</span> <span class="hlt">levels</span> and salinity intrusion. The construction of embankments and dykes has historically been the principal strategy of the Vietnamese government to mitigate the effects of salinity intrusion on agricultural production. A predicted <span class="hlt">sea-level</span> rise of 30 cm by the year 2050 is expected to accelerate salinity intrusion. This study combines hydrologic, agronomic and behavioural assessments to identify effective adaptation strategies reliant on land-use change (soft options) and investments in water infrastructure (hard options). As these strategies are managed within different policy portfolios, the political discussion has polarized between choices of either soft or hard options. This paper argues that an ensemble of hard and soft policies is likely to provide the most effective results for people's livelihoods in the Mekong Delta. The consequences of policy deliberations are likely to be felt beyond the Mekong Delta as <span class="hlt">levels</span> of rice cultivation there also affect national and global food security.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRC..120.1527W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRC..120.1527W"><span>Evidence for multidecadal variability in US extreme <span class="hlt">sea</span> <span class="hlt">level</span> records</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wahl, Thomas; Chambers, Don P.</p> <p>2015-03-01</p> <p>We analyze a set of 20 tide gauge records covering the contiguous United States (US) coastline and the period from 1929 to 2013 to identify long-term trends and multidecadal variations in extreme <span class="hlt">sea</span> <span class="hlt">levels</span> (ESLs) relative to changes in mean <span class="hlt">sea</span> <span class="hlt">level</span> (MSL). Different data sampling and analysis techniques are applied to test the robustness of the results against the selected methodology. Significant but small long-term trends in ESLs above/below MSL are found at individual sites along most coastline stretches, but are mostly confined to the southeast coast and the winter season when storm surges are primarily driven by extratropical cyclones. We identify six regions with broadly coherent and considerable multidecadal ESL variations unrelated to MSL changes. Using a quasi-nonstationary extreme value analysis, we show that the latter would have caused variations in design relevant return water <span class="hlt">levels</span> (50-200 year return periods) ranging from ˜10 cm to as much as 110 cm across the six regions. The results raise questions as to the applicability of the "MSL offset method," assuming that ESL changes are primarily driven by changes in MSL without allowing for distinct long-term trends or low-frequency variations. Identifying the coherent multidecadal ESL variability is crucial in order to understand the physical driving factors. Ultimately, this information must be included into coastal design and adaptation processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910014943','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910014943"><span>Uprated OMS Engine Status-<span class="hlt">Sea</span> <span class="hlt">Level</span> Testing Results</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bertolino, J. D.; Boyd, W. C.</p> <p>1990-01-01</p> <p>The current Space Shuttle Orbital Maneuvering Engine (OME) is pressure fed, utilizing storable propellants. Performance uprating of this engine, through the use of a gas generator driven turbopump to increase operating pressure, is being pursued by the NASA Johnson Space Center (JSC). Component <span class="hlt">level</span> design, fabrication, and test activities for this engine system have been on-going since 1984. More recently, a complete engine designated the Integrated Component Test Bed (ICTB), was tested at <span class="hlt">sea</span> <span class="hlt">level</span> conditions by Aerojet. A description of the test hardware and results of the <span class="hlt">sea</span> <span class="hlt">level</span> test program are presented. These results, which include the test condition operating envelope and projected performance at altitude conditions, confirm the capability of the selected Uprated OME (UOME) configuration to meet or exceed performance and operational requirements. Engine flexibility, demonstrated through testing at two different operational mixture ratios, along with a summary of projected Space Shuttle performance enhancements using the UOME, are discussed. Planned future activities, including ICTB tests at simulated altitude conditions, and recommendations for further engine development, are also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016cosp...41E1677S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016cosp...41E1677S"><span>Investigation of the seasonal spatial variability of the Caspian <span class="hlt">Sea</span> <span class="hlt">level</span> by satellite altimetry.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Safarov, Elnur; Mammadov, Ramiz; Cretaux, Jean-Francois; Arsen, Adalbert; Safarov, Said; Amrahov, Elvin</p> <p>2016-07-01</p> <p><span class="hlt">Sea</span> <span class="hlt">level</span> fluctuations are among the most outstanding and debated issues of the Caspian <span class="hlt">Sea</span>. Precipitation, underground water and river input are consistent parts of the inflow of the Caspian <span class="hlt">Sea</span> water balance. The river input is also considered to be the main driver of the seasonal <span class="hlt">level</span> changes of the Caspian <span class="hlt">Sea</span>. Sufficiently large amount of this input is provided by the Volga. Although there is a good network of <span class="hlt">sea</span> <span class="hlt">level</span> stations covering the coastline of the <span class="hlt">sea</span>, these facilities are not capable to reflect the <span class="hlt">sea</span> <span class="hlt">level</span> variations over the all surface. Meanwhile, the Caspian <span class="hlt">Sea</span> is well observed by satellites Jason 1, Jason 2 and ENVISAT. Altimetric data taken from these satellites covers the surface of the <span class="hlt">sea</span> much better than the data from the in-situ network stations. In this paper we investigate the spatial variability of the <span class="hlt">sea</span> <span class="hlt">level</span> that could provide more insight into the influence of river input (especially the Volga river), precipitation and other hydro-meteorological parameters on the Caspian <span class="hlt">Sea</span> <span class="hlt">level</span>.The altimetric data was averaged per every 10 square kilometers through all the tracks by means of the pre-prepared program made especially for this work. Also new maps of seasonal spatial variability of amplitude and phase of the annual signal of the Caspian <span class="hlt">Sea</span> <span class="hlt">level</span> for each investigated satellite were created by employing ARCGIS software. Moreover, these peaks of <span class="hlt">sea</span> <span class="hlt">level</span> amplitude and phase of annual signal results were comparatively analyzed with the corresponding river discharge of the Volga.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.U24A..05R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.U24A..05R"><span><span class="hlt">Sea</span> <span class="hlt">Level</span> During Past Warm Periods - Unraveling Interactions Between Climate, Ice, Crust, and Mantle</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Raymo, M. E.; Mitrovica, J. X.; Rovere, A.; O'Leary, M.; Sandstrom, R. M.; Austermann, J.; Hearty, P. J.; Deconto, R. M.; Pollard, D.</p> <p>2015-12-01</p> <p>Changes in <span class="hlt">sea</span> <span class="hlt">level</span>, whether rapid or gradual, influence the style and preservation of shorelines and near-shore features including fossil reefs, paleo-<span class="hlt">sea</span> cliffs and scarps, as well as intertidal and subtidal facies and biota. Using insight from modern shoreline systems, members of the PLIOMAX FESD project have mapped mid-Pliocene, MIS11, and MIS5e shorelines at numerous localities around the world and then modeled the effects of subsequent glacial isostatic adjustment on their current position. For MIS5e we find evidence for a rapid rise in <span class="hlt">sea</span> <span class="hlt">level</span> in the later phase of the interglacial, consistent with a collapse of the West Antarctic Ice Sheet. Estimates for maximum <span class="hlt">sea</span> <span class="hlt">level</span> during MIS5e, between 6 and 9 m, are in agreement with other studies and imply mass loss from ice sheets at both poles. For MIS11, which appears to have been slightly warmer than MIS5e, our best estimate of <span class="hlt">sea</span> <span class="hlt">level</span> rise is 6-13 m, a value subsequently narrowed to 8.5-12 m. Recent advances in ice sheet models also illustrate the potential for a substantial Antarctic contribution to elevated <span class="hlt">sea-level</span> during MIS5e and other Pliestocene interglacials including MIS11. For the Pliocene interval around 3 Ma, we cannot place useful bounds on <span class="hlt">sea</span> <span class="hlt">level</span> because shoreline features have been vertically displaced many tens of meters by mantle dynamic topographic changes of uncertain magnitude and, probably to a lesser degree, by flexure associated with sediment redistribution. However, these once horizontal shorelines, which are sometimes hundreds of kilometers long, provide useful targets against which to <span class="hlt">measure</span> the performance of time-dependent mantle convection models. Ultimately, the paleo-shoreline data is telling us that when global climate warming is more than 2°C (relative to pre-industrial, or >1°C relative to today), significant loss of ice mass occurs at high latitudes equivalent to a minimum rise in <span class="hlt">sea</span> <span class="hlt">level</span> of 6m.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFMEP41B0609O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFMEP41B0609O"><span>Can the role of the tectonic-related processes be excluded on the Caspian <span class="hlt">Sea</span> <span class="hlt">level</span> fluctuations?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ozyavas, A.; Khan, S. D.</p> <p>2009-12-01</p> <p>The Caspian <span class="hlt">Sea</span> is the largest isolated reservoir in the world and located between Russia, Azerbaijan, Iran, Turkmenistan, and Kazakhstan. Its <span class="hlt">sea</span> <span class="hlt">level</span> is 27 meter below the mean <span class="hlt">sea</span> <span class="hlt">level</span> of the world oceans. Large <span class="hlt">sea</span> <span class="hlt">level</span> fluctuations have been recorded during its history and the reasons of these <span class="hlt">sea</span> <span class="hlt">level</span> variations have long been examined. While several authors attribute <span class="hlt">sea</span> <span class="hlt">level</span> oscillations to hydroclimatic change in the basin, some suggested that the activities associated with tectonism in the basin could have potential on hydrologic budget of the CS. The water balance of the CS from 1998 to 2005 is calculated. Evaporation is quite significant in water budget calculations in the CS due to the fact that almost all of the water input is compensated by the evaporation itself and that discharge to Kara Bogaz Gol bay is relatively small. We utilize NCEP/DOE Reanalysis II meteorological data to estimate evaporation over the CS by using Penman method. Tropical Rainfall <span class="hlt">Measuring</span> Mission (TRMM) is the source for computing the direct precipitation on the <span class="hlt">sea</span> surface. The Volga River is the main water source to it and 80 % of the total inflow to it has been provided via rivers. Total river runoff data along with discharge to KBG bay have been obtained from Geophysical Center of Russian Academy of Science (RAS). Even though Volga river discharge is usually of a high correlation with the <span class="hlt">sea</span> <span class="hlt">level</span> rise and drop until 2001, precipitation over the CS together with the contribution of the rest of the rivers has also strong influence over the <span class="hlt">sea</span> <span class="hlt">level</span> fluctuations for the rest of the years. Our results reveal that <span class="hlt">sea</span> <span class="hlt">level</span> changes from 1998 to 2005 are essentially controlled by meteorological factors. However, geological processes (groundwater outflow and inflow, mud volcanoes, tectonic activity) should be included to the water budget calculations of the CS.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007GeoRL..3410405G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007GeoRL..3410405G"><span>Mediterranean <span class="hlt">Sea</span> <span class="hlt">level</span> variations during the Messinian salinity crisis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gargani, Julien; Rigollet, Christophe</p> <p>2007-05-01</p> <p>The Mediterranean Basin has not always been connected to the Atlantic Ocean. During the Messinian salinity crisis (MSC), the Mediterranean <span class="hlt">Sea</span> became progressively isolated by a complex combination of tectonic and glacio-eustatic processes. When isolated, the Mediterranean water <span class="hlt">level</span> depends on the hydrological flux and is expected to vary significantly. The amplitude and number of large water <span class="hlt">level</span> fluctuations in the isolated Mediterranean is still controversial, despite numerous geological investigations. The observation of 3-5 surfaces of erosion in the Nile delta (Eastern Basin) provides new elements for understanding the dynamics of the MSC. Our model demonstrates that numerous water <span class="hlt">level</span> falls of short duration may explain the preservation of a discontinuous river profile at ~-500 m and ~-1500 m in the Western Basin, as well as the existence of deep surfaces of erosion in the Eastern Basin.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMOS33C1087Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMOS33C1087Y"><span>Current Land Subsidence and <span class="hlt">Sea</span> <span class="hlt">Level</span> Rise along the North American Coastal Region: Observations from 10-Year (2005-2014) Closely-Spaced GPS and Tide Gauge Stations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, L.; Yu, J.; Kearns, T.; Wang, G.</p> <p>2014-12-01</p> <p>Strong evidence has proved that the global <span class="hlt">sea-level</span> is now rising at an increased rate and it is projected to continue to rise. However the rise of the <span class="hlt">sea-level</span> is not uniform around the world. The local or relative <span class="hlt">sea-level</span> rise will be of great concern to the coastal regions. The combination of the land subsidence and global <span class="hlt">sea-level</span> rise causes the relative <span class="hlt">sea-level</span> to rise. Relative <span class="hlt">sea-level</span> rise increases the risk of flooding and wetland loss problems in near coastal areas, which in turn have important economic, environmental, and human health consequences for the heavily populated and ecologically important coastal region. However the role played by the coastal land subsidence is commonly absent during the discussion of <span class="hlt">sea-level</span> rise problems. The <span class="hlt">sea-level</span> can be <span class="hlt">measured</span> in two ways: satellite altimetry and tide gauges. The <span class="hlt">sea-level</span> <span class="hlt">measured</span> by satellite is called the geocentric <span class="hlt">sea-level</span> that is relative to earth center and the one <span class="hlt">measured</span> by tide gauges is called local <span class="hlt">sea-level</span> that is relative to the land. The tide gauge <span class="hlt">measurements</span> of the local <span class="hlt">sea-level</span> do not distinguish between whether the water is rising or the land is subsiding. In some coastal areas, land subsidence is occurring at a higher rate than the geocentric <span class="hlt">sea-level</span> is rising. This can have a great local effect. GPS technology has proven to be efficient and accurate for <span class="hlt">measuring</span> and tracking absolute land elevation change. There are about 300 publically available Continuously Operating Reference GPS Stations (CORS) within 15 km from the coastal line along North America. In this study, we use publicly available long-history (> 5 years) CORS data to derive current (2005-2014) coastal subsidence in North America. Absolute coastal <span class="hlt">sea-level</span> rise will be determined by combing the land subsidence and relative <span class="hlt">sea-level</span> <span class="hlt">measurements</span>. This study shows that the relative <span class="hlt">sea-level</span> of the Alaska area appears to be falling because the land is uplifting; this study also shows that the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JCR....32.1247W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JCR....32.1247W"><span>Acceleration in U.S. Mean <span class="hlt">Sea</span> <span class="hlt">Level</span>? A New Insight using Improved Tools</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Watson, Phil J.</p> <p>2016-08-01</p> <p>The detection of acceleration in mean <span class="hlt">sea</span> <span class="hlt">level</span> around the data-rich margins of the United States has been a keen endeavour of <span class="hlt">sea-level</span> researchers following the seminal work of Bruce Douglas in 1992. Over the past decade, such investigations have taken on greater prominence given mean <span class="hlt">sea</span> <span class="hlt">level</span> remains a key proxy by which to <span class="hlt">measure</span> a changing climate system. The physics-based climate projection models are forecasting that the current global average rate of mean <span class="hlt">sea-level</span> rise (≈3 mm/y) might climb to rates in the range of 10020 mm/y by 2100. Most research in this area has centred on reconciling current rates of rise with the significant accelerations required to meet the forecast projections of climate models. The analysis in this paper is based on a recently developed analytical package titled "msltrend," specifically designed to enhance estimates of trend, real-time velocity and acceleration in the relative mean <span class="hlt">sea-level</span> signal derived from long annual average ocean-water-<span class="hlt">level</span> time series. Key findings are that at the 95% confidence <span class="hlt">level</span>, no consistent or substantial evidence (yet) exists that recent rates of rise are higher or abnormal in the context of the historical records available for the United States, nor does any evidence exist that geocentric rates of rise are above the global average. It is likely that a further 20 years of data will identify whether recent increases east of Galveston and along the east coast are evidence of the onset of climate change induced acceleration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1711972M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1711972M"><span><span class="hlt">Measurements</span> of <span class="hlt">sea</span> ice proxies from Antarctic coastal shallow cores</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Maffezzoli, Niccolò; Vallelonga, Paul; Spolaor, Andrea; Barbante, Carlo; Frezzotti, Massimo</p> <p>2015-04-01</p> <p>Despite its close relationship with climate, the climatic impact of <span class="hlt">sea</span> ice remains only partially understood: an indication of this is the Arctic <span class="hlt">sea</span> ice which is declining at a faster rate than models predict. Thus, the need for reliable <span class="hlt">sea</span> ice proxies is of crucial importance. Among the <span class="hlt">sea</span> ice proxies that can be extracted from ice cores, interest has recently been shown in the halogens Iodine (I) and Bromine (Br) (Spolaor, A., et al., 2013a, 2013b). The production of <span class="hlt">sea</span> ice is a source of Sodium and Bromine aerosols through frost flower crystal formation and sublimation of salty blowing snow, while Iodine is emitted by the algae living underneath <span class="hlt">sea</span> ice. We present here the results of Na, Br and I <span class="hlt">measurements</span> in Antarctic shallow cores, drilled during a traverse made in late 2013 - early 2014 from Talos Dome (72° 00'S, 159°12'E) to GV7 (70° 41'S, 158° 51'E) seeking for <span class="hlt">sea</span> ice signature. The samples were kept frozen until the analyses, that were carried out by Sector Field Mass Spectroscopy Inductive Coupled Plasma (SFMS-ICP): special precautions and experimental steps were adopted for the detection of such elements. The coastal location of the cores allows a clear signal from the nearby <span class="hlt">sea</span> ice masses. The multiple cores are located about 50 km from each other and can help us to infer the provenance of the <span class="hlt">sea</span> ice that contributed to the proxy signature. Moreover, by simultaneously determining other chemical elements and compounds in the snow, it is possible to determine the relative timing of their deposition, thus helping us to understand their processes of emission and deposition.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19740006156','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19740006156"><span>Toward RADSCAT <span class="hlt">measurements</span> over the <span class="hlt">sea</span> and their interpretation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Claassen, J. P.; Fung, A. K.; Wu, S. T.; Chan, H. L.</p> <p>1973-01-01</p> <p>Investigations into several areas which are essential to the execution and interpretation of suborbital observations by composite radiometer - scatterometer sensor (RADSCAT) are reported. Experiments and theory were developed to demonstrate the remote anemometric capability of the sensor over the <span class="hlt">sea</span> through various weather conditions. It is shown that weather situations found in extra tropical cyclones are useful for demonstrating the all weather capability of the composite sensor. The large scale fluctuations of the wind over the <span class="hlt">sea</span> dictate the observational coverage required to correlate <span class="hlt">measurements</span> with the mean surface wind speed. Various theoretical investigations were performed to establish a premise for the joint interpretation of the experiment data. The effects of clouds and rains on downward radiometric observations over the <span class="hlt">sea</span> were computed. A method of predicting atmospheric attenuation from joint observations is developed. In other theoretical efforts, the emission and scattering characteristics of the <span class="hlt">sea</span> were derived. Composite surface theories with coherent and noncoherent assumptions were employed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFMPP13C1478G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFMPP13C1478G"><span>Discovery of Lower Pleistocene Shallow-marine Deposits on Mayaguana Island, Bahamas. Implications for Eustatic <span class="hlt">Sea-Level</span> Curves Derived From Deep-<span class="hlt">Sea</span> Oxygen-Isotope Records</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Godefroid, F.; Kindler, P.; Chiaradia, M.; Hasler, C.; Samankassou, E.</p> <p>2008-12-01</p> <p>87Sr/86Sr-dated marine and beach sediments exposed along the north shore of Mayaguana Island (Bahamas) provide new estimates of the elevation of high <span class="hlt">sea</span> stands during the Early Pleistocene that will contribute to better calibrate eustatic <span class="hlt">sea-level</span> curves derived from deep-<span class="hlt">sea</span> oxygen-isotope records. A newly investigated <span class="hlt">sea</span> cliff located to the west of Mount Misery Point on the northern coast of Mayaguana, in the SE part of the Bahamian archipelago, includes two vertically stacked sequences of shallow-marine carbonates separated and capped by paleosols and eolianites. The lower unit, reaching up to 5.5 m above modern <span class="hlt">sea</span> <span class="hlt">level</span>, consists of coarse laminated calcarenites containing numerous mollusk and red-algal fragments, and large in-situ coral specimens (Diploria strigosa). The second unit, exposed between 7.3 and 10 m, includes bioturbated, coral-rich limestones, overlain by thinly bedded calcarenites characterized by an early generation of fibrous rim cement. 87Sr/86Sr ratios <span class="hlt">measured</span> from these carbonates range from 0.709123 at the base of the section to 0.709142 at its top. The first unit can be interpreted as a peri-reefal facies deposited when relative <span class="hlt">sea</span> <span class="hlt">level</span> was at least 5.5 m above present. The second unit corresponds to one shallowing-upward sequence of subtidal and beach deposits generated when <span class="hlt">sea</span> <span class="hlt">level</span> was around 9 m above its actual stand. Sr-isotope ratios indicate that both units were formed during the Early Pleistocene, likely between 1.6 and 1.0 Ma BP. Comparison with existing oxygen-isotope records from deep- <span class="hlt">sea</span> sediments suggests that the identified <span class="hlt">sea-level</span> highstands could correspond to negative δ18O peaks estimated at 1.45 and 1.50 Ma BP. Based on the elevation of fossil reefs dating from the last interglacial (Marine Isotope Stage 5e) and the occurrence of Upper Miocene shallow-marine deposits close to modern <span class="hlt">sea</span> <span class="hlt">level</span>, Mayaguana can be considered as tectonically stable. The elevation values obtained for these Early Pleistocene</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20065715','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20065715"><span>ESR dating pleistocene barnacles from BC and Maine: a new method for tracking <span class="hlt">sea</span> <span class="hlt">level</span> change.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Blackwell, Bonnie A B; Gong, J J J; Skinner, Anne R; Blais-Stevens, Andrée; Nelson, Robert E; Blickstein, Joel I B</p> <p>2010-02-01</p> <p>Barnacles have never been successfully dated by electron spin resonance (ESR). Living mainly in the intertidal zone, barnacles die when <span class="hlt">sea</span> <span class="hlt">level</span> changes cause their permanent exposure. Thus, dating the barnacles dates past <span class="hlt">sea</span> <span class="hlt">level</span> changes. From this, we can <span class="hlt">measure</span> apparent <span class="hlt">sea</span> <span class="hlt">level</span> changes that occur due to ocean volume changes, crustal isostasy, and tectonics. ESR can date aragonitic mollusc shells ranging in age from 5 ka to at least 500 ka. By modifying the standard ESR method for molluscs to chemically dissolve 20 microm from off the shells, six barnacle samples from Norridgewock, Maine, and Khyex River, British Columbia, were tested for suitability for ESR dating. Due to Mn2+ interference peaks, the four Maine barnacle samples were not datable by ESR. Two barnacles from BC, which lacked Mn2+ interference, yielded a mean ESR age of 15.1 +/- 1.0 ka. These ages agree well with 14C dates on the barnacles themselves and wood in the overlying glaciomarine sediment. Although stability tests to calculate the mean dating signal lifetime and more ESR calibration tests against other barnacles of known age are needed to ensure the method's accuracy, ESR can indeed date Balanus, and thus, <span class="hlt">sea</span> <span class="hlt">level</span> changes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002CSR....22..779D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002CSR....22..779D"><span><span class="hlt">Sea</span> <span class="hlt">level</span> oscillations in coastal waters of the Buenos Aires province, Argentina</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dragani, W. C.; Mazio, C. A.; Nuñez, M. N.</p> <p>2002-03-01</p> <p><span class="hlt">Sea</span> <span class="hlt">level</span> oscillations, with periods ranging from a few minutes to almost 2 h, have been observed at various tide stations located on the coast of Buenos Aires. Simultaneous records of <span class="hlt">sea</span> <span class="hlt">level</span> elevation <span class="hlt">measured</span> in Mar de Ajó, Pinamar and Mar del Plata during 1982 have been spectrally analyzed. Significant spectral energy has been detected between 0.85 and 4.69 cycles per hour (cph) and the most energetic peaks have frequencies between 1.17 and 1.49 cph. Spectra, coherence, and phase difference have been analyzed for the most energetic event of the year. During that event, the most intensive spectral peak is at 1.17 cph for Mar de Ajó and Pinamar, and at 1.49 cph for Mar del Plata. Simultaneous total energy peaks at Mar de Ajó, Pinamar and Mar del Plata, and the coherence function estimated between Mar de Ajó and Pinamar suggests that <span class="hlt">sea</span> <span class="hlt">level</span> oscillations could be a regional phenomenon. The analyzed data suggest that <span class="hlt">sea</span> <span class="hlt">level</span> oscillations could be forced by atmospheric gravity waves associated with frontal passages.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.G53C0693M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.G53C0693M"><span>Implementation of CGPS at Estartit, Ibiza and Barcelona harbours for <span class="hlt">sea</span> <span class="hlt">level</span> monitoring</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Martinez-Benjamin, J. J.; Ortiz Castellon, M.; Martinez-Garcia, M.; Perez, B.; Bosch, E.; Termens, A.; Martinez de Oses, X.</p> <p>2009-12-01</p> <p>The determination of global and regional mean <span class="hlt">sea</span> <span class="hlt">level</span> variations with accura-cies better than 1 mm/yr is a critical problem, the resolution of which is central to the current debate on climate change and its impact on the environment. Highly accurate time series from both satellite altimetry and tide gauges are needed. <span class="hlt">Measuring</span> the <span class="hlt">sea</span> surface height with in-situ tide gauges and GPS receivers pro-vides an efficient way to control the long term stability of the radar altimeters and other applications as the vertical land motion and studies of <span class="hlt">sea</span> <span class="hlt">level</span> change. L’Estartit tide gauge is a classical floating tide gauge set up in l’Estartit harbour (NE Spain) in 1990. Data are taken in graphics registers from which each two hours the mean value is recorded in an electronic support and delivered to the Permanent Service for Mean <span class="hlt">Sea</span> <span class="hlt">level</span> (PSMSL). Periodic surveying campaigns along the year are carried out for monitoring possible vertical movement of the geodetic benchmark adjacent to the tide gauge. Puertos del Estado (Spanish Harbours) installed the tide gauge station at Ibiza har-bour in January 2003 and a near GPS reference station. The station belongs to the REDMAR network, composed at this moment by 21 stations distributed along the whole Spanish waters, including also the Canary islands (http://www.puertos.es). The tide gauge also belongs to the ESEAS (European <span class="hlt">Sea</span> <span class="hlt">Level</span>) network. A description of the actual infrastructure at Ibiza, Barcelona and l’Estartit har-bours is presented.The main objective is the implementation of these harbours as a precise geodetic areas for <span class="hlt">sea</span> <span class="hlt">level</span> monitoring and altimeter calibration. Actually is a CGPS with a radar tide gauge from Puertos del Estado and a GPS belonging to Puerto de Barcelona. A precise <span class="hlt">levelling</span> has been made by the Cartographic Insti-tute of Catalonia, ICC. The instrumentation of <span class="hlt">sea</span> <span class="hlt">level</span> <span class="hlt">measurements</span> has been improved by providing the Barcelona site with a radar tide gauge Datamar 3000C device and a</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.5572B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.5572B"><span>IODP Expedition 359: Maldives Monsoon and <span class="hlt">Sea</span> <span class="hlt">Level</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Betzler, Christian; Eberli, Gregor; Zarikian, Carlos</p> <p>2016-04-01</p> <p>Drilling the carbonate platforms and drifts in the Maldives aimed to recover the marine tropical record of the Neogene <span class="hlt">sea-level</span> changes and the onset of the monsoon related current system in the Indian Ocean. To reach this goal, eight sites were drilled along two transects in the Kardiva Channel in the Inner <span class="hlt">Sea</span> of the Maldives during IODP Expedition 359. The recovered cores and log data retrieved the material to achieve all the objectives set for the expedition. The most arresting accomplishment is the documentation of how the <span class="hlt">sea</span> <span class="hlt">level</span> controlled the carbonate platform system that was thriving during the Miocene Climate Optimum abruptly transitioned into a current-dominated system in the late Middle Miocene. This transition is linked to the onset of an early intensification of the Indian monsoon and the coeval demise of some of the Maldivian platforms. Cores and downhole logs allowed producing a solid record and reconstructing the Neogene environmental changes in the central Indian Ocean. Preliminary shipboard analyses allow a precise dating of this major paleoclimatological and paleoceanographical changes, as it also applies for the extension of the Oxygen Minimum Zone (OMZ) into this part of the Indian Ocean. Coring produced a solid framework to foster the post-cruise research of these distinct topics. In addition, complete spliced sections and logging at key sites during Expedition 359 provide the potential to assemble a cycle-based astrochronology for the Neogene section in the Maldives. This high-resolution chronology will allow: 1) independent ages to be assigned to key biostratigraphic events in the Maldives for comparison with those from other tropical regions; 2) more precise ages for the major sequence boundaries and unconformities; and 3) evaluation of higher-resolution sedimentation rate variations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70016863','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70016863"><span>General circulation model simulations of winter and summer <span class="hlt">sea-level</span> pressures over North America</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>McCabe, G.J.; Legates, D.R.</p> <p>1992-01-01</p> <p>In this paper, observed <span class="hlt">sea-level</span> pressures were used to evaluate winter and summer <span class="hlt">sea-level</span> pressures over North America simulated by the Goddard Institute for Space Studies (GISS) and the Geophysical Fluid Dynamics Laboratory (GFDL) general circulation models. The objective of the study is to determine how similar the spatial and temporal distributions of GCM-simulated daily <span class="hlt">sea-level</span> pressures over North America are to observed distributions. Overall, both models are better at reproducing observed within-season variance of winter and summer <span class="hlt">sea-level</span> pressures than they are at simulating the magnitude of mean winter and summer <span class="hlt">sea-level</span> pressures. -from Authors</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11679666','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11679666"><span><span class="hlt">Sea</span> <span class="hlt">level</span> rise during past 40 years determined from satellite and in situ observations.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cabanes, C; Cazenave, A; Le Provost, C</p> <p>2001-10-26</p> <p>The 3.2 +/- 0.2 millimeter per year global mean <span class="hlt">sea</span> <span class="hlt">level</span> rise observed by the Topex/Poseidon satellite over 1993-98 is fully explained by thermal expansion of the oceans. For the period 1955-96, <span class="hlt">sea</span> <span class="hlt">level</span> rise derived from tide gauge data agrees well with thermal expansion computed at the same locations. However, we find that subsampling the thermosteric <span class="hlt">sea</span> <span class="hlt">level</span> at usual tide gauge positions leads to a thermosteric <span class="hlt">sea</span> <span class="hlt">level</span> rise twice as large as the "true" global mean. As a possible consequence, the 20th century <span class="hlt">sea</span> <span class="hlt">level</span> rise estimated from tide gauge records may have been overestimated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.A43C0291P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.A43C0291P"><span><span class="hlt">Measurements</span> of Hygroscopicity- and Size-Resolved <span class="hlt">Sea</span> Spray Aerosol</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Phillips, B.; Dawson, K. W.; Royalty, T. M.; Reed, R. E.; Petters, M.; Meskhidze, N.</p> <p>2015-12-01</p> <p>Atmospheric aerosols play a central role in many environmental processes by influencing the Earth's radiative balance, tropospheric chemistry, clouds, biogeochemical cycles, and visibility as well as adversely impacting human health. Based on their origin, atmospheric aerosols can be defined as anthropogenic or natural. Recent studies have shown that a large fraction of uncertainty in the radiative effects of anthropogenic aerosols is related to uncertainty in natural—background—aerosols. Marine aerosols are of particular interest due to the abundance of oceans covering the Earth's surface. Despite their importance, limited information is currently available for size- and composition-resolved marine aerosol emission fluxes. Our group has designed and built an instrument for <span class="hlt">measuring</span> the size- and hygroscopicity-resolved <span class="hlt">sea</span> spray aerosol fluxes. The instrument was first deployed during spring 2015 at the end of the 560 m pier of the US Army Corps of Engineers' Field Research Facility in Duck, NC. <span class="hlt">Measurements</span> include 200 nm-sized diameter growth factor (hygroscopicity) distributions, <span class="hlt">sea</span> spray particle flux <span class="hlt">measurements</span>, and total sub-micron sized aerosol concentration. Ancillary ocean data includes salinity, pH, <span class="hlt">sea</span> surface temperature, dissolved oxygen content, and relative fluorescence (proxy for [Chl-a]). Hygroscopicity distribution <span class="hlt">measurements</span> show two broad peaks, one indicative of organics and sulfates and another suggestive of <span class="hlt">sea</span> salt. The fraction of 200 nm-sized salt particles having hygroscopicity similar to that of <span class="hlt">sea</span>-spray aerosol contributes up to ~24% of the distribution on days with high-speed onshore winds and up to ~3% on calm days with winds blowing from the continent. However, the total concentration of <span class="hlt">sea</span>-spray-like particles originating from offshore versus onshore winds was relatively similar. Changes in the relative contribution of <span class="hlt">sea</span>-salt to number concentration were caused by a concomitant changes in total aerosol concentration</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.A42D..04B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.A42D..04B"><span>Eddy Covariance <span class="hlt">Measurements</span> of the <span class="hlt">Sea</span>-Spray Aerosol Flu</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brooks, I. M.; Norris, S. J.; Yelland, M. J.; Pascal, R. W.; Prytherch, J.</p> <p>2015-12-01</p> <p>Historically, almost all estimates of the <span class="hlt">sea</span>-spray aerosol source flux have been inferred through various indirect methods. Direct estimates via eddy covariance have been attempted by only a handful of studies, most of which <span class="hlt">measured</span> only the total number flux, or achieved rather coarse size segregation. Applying eddy covariance to the <span class="hlt">measurement</span> of <span class="hlt">sea</span>-spray fluxes is challenging: most instrumentation must be located in a laboratory space requiring long sample lines to an inlet collocated with a sonic anemometer; however, larger particles are easily lost to the walls of the sample line. Marine particle concentrations are generally low, requiring a high sample volume to achieve adequate statistics. The highly hygroscopic nature of <span class="hlt">sea</span> salt means particles change size rapidly with fluctuations in relative humidity; this introduces an apparent bias in flux <span class="hlt">measurements</span> if particles are sized at ambient humidity. The Compact Lightweight Aerosol Spectrometer Probe (CLASP) was developed specifically to make high rate <span class="hlt">measurements</span> of aerosol size distributions for use in eddy covariance <span class="hlt">measurements</span>, and the instrument and data processing and analysis techniques have been refined over the course of several projects. Here we will review some of the issues and limitations related to making eddy covariance <span class="hlt">measurements</span> of the <span class="hlt">sea</span> spray source flux over the open ocean, summarise some key results from the last decade, and present new results from a 3-year long ship-based <span class="hlt">measurement</span> campaign as part of the WAGES project. Finally we will consider requirements for future progress.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1990QuRes..33....1H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1990QuRes..33....1H"><span>South Carolina interglacial sites and stage 5 <span class="hlt">sea</span> <span class="hlt">levels</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hollin, John T.; Hearty, Paul J.</p> <p>1990-01-01</p> <p>Amino acid and other studies have been made on the 30-km Pleistocene sections of the Intracoastal Waterway between Myrtle Beach and Little River, South Carolina. Our ratios differentiate the long-established Waccamaw (oldest), Canepatch, and Socastee formations. The ratios from the four laboratories that have worked in this area agree very well, and apparent conflicts with U-series dates may merely reflect an abundance of reworked corals. Our amino acid correlations with U-series coral dates in South Carolina, Bermuda, and the Mediterranean all argue that the classical Canepatch and its Horry Clay date from isotope stage 5e and not, as has been implied, from stage 7, 9, 11, or 13. Excavations and erosion have increased position-fixing problems along the Waterway, and "Canepatch" amino acid ratios and U-series dates (460,000 ± 100,000 yr B.P.) at "ICW5" may be from an older unit. The Canepatch shows the double marine transgression visible in many stage 5e deposits. Pollen shows that the second transgression occurred late in the interglaciation, and stratigraphic studies show that it reached 14 m. It therefore fits very well Antarctic ice-surge models of stage 5 <span class="hlt">sea</span> <span class="hlt">level</span> and climate. The Socastee adds to the evidence for one or more <span class="hlt">sea</span> <span class="hlt">levels</span> above 0 m late in stage 5.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017OcSci..13...47B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017OcSci..13...47B"><span>Changes in extreme regional <span class="hlt">sea</span> <span class="hlt">level</span> under global warming</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brunnabend, S.-E.; Dijkstra, H. A.; Kliphuis, M. A.; Bal, H. E.; Seinstra, F.; van Werkhoven, B.; Maassen, J.; van Meersbergen, M.</p> <p>2017-01-01</p> <p>An important contribution to future changes in regional <span class="hlt">sea</span> <span class="hlt">level</span> extremes is due to the changes in intrinsic ocean variability, in particular ocean eddies. Here, we study a scenario of future dynamic <span class="hlt">sea</span> <span class="hlt">level</span> (DSL) extremes using a high-resolution version of the Parallel Ocean Program and generalized extreme value theory. This model is forced with atmospheric fluxes from a coupled climate model which has been integrated under the IPCC-SRES-A1B scenario over the period 2000-2100. Changes in 10-year return time DSL extremes are very inhomogeneous over the globe and are related to changes in ocean currents and corresponding regional shifts in ocean eddy pathways. In this scenario, several regions in the North Atlantic experience an increase in mean DSL of up to 0.4 m over the period 2000-2100. DSL extremes with a 10-year return time increase up to 0.2 m with largest values in the northern and eastern Atlantic.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMGC13A1051K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMGC13A1051K"><span>Eco-technological management of Tuvalu against <span class="hlt">sea</span> <span class="hlt">level</span> rise</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kayanne, H.</p> <p>2012-12-01</p> <p>Atoll island is formed and maintained by sand production, transportation and sedimentation process. Major component of sand in the Pacific atolls is foraminifera, which is produced on the ocean-side reef flat, and then transported from the ocean-side to the lagoon-side coast through channels between the islands. Sand is then transported along the lagoon-side coast by longshore current, and finally deposited to nourish sandy beach. At present, however, this natural process has been deteriorated by local human stresses. High production of foraminifera and corals are degraded by human waste. Transportation of sand from the ocean to the lagoon is blocked by a causeway, and longshore transportation and sedimentation along the lagoon coast is prevented by jetties, dredges and upright seawalls. All these local factors severely reduce natural resilience and increase vulnerability against the projected future <span class="hlt">sea</span> <span class="hlt">level</span> rise and the global changes. Countermeasure plans must be based on and must not conflict with the natural island formation process. We launched "Eco-technological management of Tuvalu against <span class="hlt">sea</span> <span class="hlt">level</span> rise" under Science and Technology Research Partnership for Sustainable Development funded by JICA and JST. The goal of this project is to regenerate sandy beach along Fongafale Island, Funrafuti Atoll Tuvalu by rehabilitation of production, transportation and sedimentation process including establishing foraminifera culture system.; Fig. 1 Aerial view of Fongafale Is., Funafuti Atoll, Tuvalu.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.9121S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.9121S"><span>A High School Project Seminar on <span class="hlt">Sea</span> <span class="hlt">Level</span> Rise</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Seitz, M.; Bosch, W.</p> <p>2012-04-01</p> <p>In Bavaria the curriculum of the upper grade of high school includes a so called project seminar, running over one and a half year. The aims of the seminar are to let the pupils learn to work on a specifi