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Sample records for sea level muon

  1. The stopping rate of negative cosmic-ray muons near sea level

    NASA Technical Reports Server (NTRS)

    Spannagel, G.; Fireman, E. L.

    1971-01-01

    A production rate of 0.065 + or - 0.003 Ar-37 atom/kg min of K-39 at 2-mwe depth below sea level was measured by sweeping argon from potassium solutions. This rate is unaffected by surrounding the solution by paraffin and is attributed to negative muon captures and the electromagnetic interaction of fast muons, and not to nucleonic cosmic ray component. The Ar-37 yield from K-39 by the stopping of negative muons in a muon beam of a synchrocyclotron was measured to be 8.5 + or - 1.7%. The stopping rate of negative cosmic ray muons at 2-mwe depth below sea level from these measurements and an estimated 17% electromagnetic production is 0.63 + or - 0.13 muon(-)/kg min. Previous measurements on the muon stopping rate vary by a factor of 5. Our value is slightly higher but is consistent with two previous high values. The sensitivity of the Ar-37 radiochemical method for the detection of muons is considerably higher than that of the previous radiochemical methods and could be used to measure the negative muon capture rates at greater depths.

  2. Azimuthal angular dependence study of the atmospheric muon charge ratio at sea level using Geant4

    NASA Astrophysics Data System (ADS)

    Arslan, Halil; Bektasoglu, Mehmet

    2012-05-01

    The azimuth dependence of the cosmic muon charge ratio at sea level was estimated using the Geant4 simulation package. Simulations were separately run at 12 azimuth angles ranging from 0° to 330° with 30° increment. Two hundred thousand proton and alpha particles were randomly distributed over the zenith angle range 30° < θ < 40° at each azimuth angle. The kinetic energy spectra of proton and helium nuclei were taken from the balloon-flight measurements. The atmospheric muon charge ratio was calculated at each azimuthal angle for low energy muons with a mean momentum around 0.5 GeV/c. The Geant4 simulation results have been compared with those of the CORSIKA simulation program and with the WILLI measurements. The simulation results reproduce well the measured east-west effect with a non-zero asymmetry AEW = 0.24. This asymmetry in the charge ratio decreases from 0.37 to 0.19 as the momentum increases from 0.22 to 0.70 GeV/c.

  3. Muon enhancements at sea level in association with Swift-BAT and MILAGRO triggers

    SciTech Connect

    Augusto, C. R. A.; Navia, C. E.; Tsui, K. H.

    2008-06-15

    Recently, triggers occurring during high background rate intervals have been reporter by the Swift-BAT gamma-ray burst detector. Among them, there were two on January 24, two on January 25, and two on February 13 and 18, all in 2008. These Swift-BAT triggers in most cases are probably noise triggers that occurred while Swift was entering the South Atlantic Anomaly (SAA). In fact, we show that they happen during a plentiful precipitation of high energy particles in the SAA, producing muons in the atmosphere detected by two directional telescopes at sea level, inside the SAA region (Tupi experiment). They look like sharp peaks in the muon counting rate. In the same category are two triggers from the MILAGRO ground-based detector, on January 25 and 31, 2008, respectively. In addition, the trigger coordinates are close to (and, in two cases, inside) the field of view of the telescopes. From an additional analysis in the behavior of the muon counting rate, it is possible to conclude that the events are produced by precipitation of high energy charged particles in the SAA region. Thus, due to its localization, the Tupi experiment constitutes a new sensor of high energy particle precipitation in the SAA, and it can be useful in the identification of some triggers of gamma-ray burst detectors.

  4. Estimation of vertical sea level muon energy spectra from the latest primary cosmic ray elemental spectra

    NASA Astrophysics Data System (ADS)

    Mitra, M.; Molla, N. H.; Bhattacharyya, D. P.

    The directly measured elemental spectra of primary cosmic rays obtained from Webber et al., Seo et al., Menn et al., Ryan et al. and experiments like JACEE, CRN, SOKOL, RICH on P, He, CNO, Ne-S and Fe have been considered to estimate the vertical sea level muon energy spectra. The primary elemental energy spectra of P, He, CNO, Ne-S and Fe available from the different experimental data duly fitted by power law are given by Np(E)dE = 1.2216E-2.68 dE [cm2 .s.sr.GeV/n]-1 NHe(E)dE = 0.0424E-2.59 dE [cm2 .s.sr.GeV/n]-1 NCNO(E)dE = 0.0026E-2.57 dE[cm2 .s.sr.GeV/n]-1 NNe-S(E)dE = 0.00066E-2.57 dE [cm2 .s.sr.GeV/n]-1 NF e(E)dE = 0.0056E-2.55 dE [cm2 .s.sr.GeV/n]-1 Using the conventional superposition model the all nucleon primary cosmic ray spectrum has been derived which is of the form N(E)dE = 1.42E-2.66 dE [cm2 .s.sr.GeV/n]-1 We have considered all these spectra separately as parents of the secondary mesons and finallty the sea level muon fluxes at 00 from each species have been derived. To evaluate the meson spectra which are the initial air shower interaction products initiated by the primary nucleon air collisions, the hadronic energy moments have been calculated from the CERN LEBCEHS data for pp collisions and FNAL data for πp collisions. Pion production by secondary pions have been taken into account and the final total muon spectrum has been derived from pp rightarrowπ± x, pp → K± x, πp → π± x channels. The Z-factors have been corrected for p-air collisions. We have adopted the constant values of σp-air and σπ-air crosssections which are 273 mb and 213 mb, respectively. The adopted inelastic cross-sections for pp and πp interactions are 35 mb and 22 mb, respectively. The Q-G plasma correction of Z-factors have also been incorporated in the final form. The solution to the standard differential equation for mesons is considered for muon flux estimation from Ngenerations of the parent mesons. By this formulation vertical muon spectra from each element

  5. Angular and energy distribution for parent primaries of cosmic muons at the sea level using Geant4

    NASA Astrophysics Data System (ADS)

    Arslan, Halil; Bektasoglu, Mehmet

    2015-04-01

    The angular and energy distributions of the primary cosmic rays that are responsible for the muons reaching the sea level have been estimated using the Geant4 simulation package. The models used in the simulations were tested by comparing the simulation results for the differential muon flux with the BESS measurements performed in Lynn Lake, Canada. Then, direct relationship between the propagation directions of the muons and those of the responsible primary particles has been investigated. The median energies for the parent primaries of vertical muons reaching the sea level with the threshold energies (Eμ) in the range 0.5-300 GeV were obtained. Simulation results for the median primary energies, 15.5Eμ and 11.2Eμ for Eμ = 14 GeV and Eμ = 100 GeV, have been found to be in good agreement with the literature. Furthermore, median primary energies for the low energy muons with large zenith angle have been seen to be relatively higher than the ones for the muons with narrower angles.

  6. VARIATIONS OF THE MUON FLUX AT SEA LEVEL ASSOCIATED WITH INTERPLANETARY ICMEs AND COROTATING INTERACTION REGIONS

    SciTech Connect

    Augusto, C. R. A.; Kopenkin, V.; Navia, C. E.; Tsui, K. H.; Shigueoka, H.; Fauth, A. C.; Kemp, E.; Manganote, E. J. T.; Leigui de Oliveira, M. A.; Miranda, P.; Ticona, R.; Velarde, A.

    2012-11-10

    We present the results of an ongoing survey on the association between the muon flux variation at ground level (3 m above sea level) registered by the Tupi telescopes (Niteri-Brazil, 22.{sup 0}9S, 43.{sup 0}2W, 3 m) and the Earth-directed transient disturbances in the interplanetary medium propagating from the Sun (such as coronal mass ejections (CME), and corotating interaction regions (CIRs)). Their location inside the South Atlantic Anomaly region enables the muon telescopes to achieve a low rigidity of response to primary and secondary charged particles. The present study is primarily based on experimental events obtained by the Tupi telescopes in the period from 2010 August to 2011 December. This time period corresponds to the rising phase of solar cycle 24. The Tupi events are studied in correlation with data obtained by space-borne detectors (SOHO, ACE, GOES). Identification of interplanetary structures and associated solar activity was based on the nomenclature and definitions given by the satellite observations, including an incomplete list of possible interplanetary shocks observed by the CELIAS/MTOF Proton Monitor on the Solar and Heliospheric Observatory (SOHO) spacecraft. Among 29 experimental events reported in the present analysis, there are 15 possibly associated with the CMEs and sheaths, and 3 events with the CIRs (forward or reverse shocks); the origin of the remaining 11 events has not been determined by the satellite detectors. We compare the observed time (delayed or anticipated) of the muon excess (positive or negative) signal on Earth (the Tupi telescopes) with the trigger time of the interplanetary disturbances registered by the satellites located at Lagrange point L1 (SOHO and ACE). The temporal correlation of the observed ground-based events with solar transient events detected by spacecraft suggests a real physical connection between them. We found that the majority of observed events detected by the Tupi experiment were delayed in

  7. Sea-level muon spectrum in the energy range 1-10 TeV from the data of underground experiments

    SciTech Connect

    Lagutin, A. A. Yushkov, A. V.

    2006-03-15

    Within an adjoint approach, the properties of the muon component in various types of rock and in water are calculated with allowance for fluctuations of energy losses in all muon-interaction processes. The behavior of the muon spectrum at sea level is established on the basis of a comparison of the muon absorption curves obtained in this way and experimental data from underground facilities. It is shown that the deficit of the calculated muon flux obtained with the aid of data from direct measurements of the spectra of primary nuclei and Reggeon models of nuclear interactions is not less than 50% in the energy range 1-10 TeV.

  8. Measurement of integrated flux of cosmic ray muons at sea level using the INO-ICAL prototype detector

    SciTech Connect

    Pal, S.; Acharya, B.S.; Majumder, G.; Mondal, N.K.; Samuel, D.; Satyanarayana, B. E-mail: acharya@tifr.res.in E-mail: nkm@tifr.res.in E-mail: bsn@tifr.res.in

    2012-07-01

    The India-based Neutrino Observatory (INO) collaboration is planning to set-up a magnetized Iron-CALorimeter (ICAL) to study atmospheric neutrino oscillations with precise measurements of oscillations parameters. The ICAL uses 50 kton iron as target mass and about 28800 Resistive Plate Chambers (RPC) of 2 m × 2 m in area as active detector elements. As part of its R and D program, a prototype detector stack comprising 12 layers of RPCs of 1 m × 1 m in area has been set-up at Tata Institute of Fundamental Research (TIFR) to study the detector parameters using cosmic ray muons. We present here a study of muon flux measurement at sea level and lower latitude. (Site latitude: 18°54'N, longitude: 72°48'E.)

  9. Analytical calculation of muon intensities under deep sea-water

    NASA Technical Reports Server (NTRS)

    Inazawa, H.; Kobayakawa, K.

    1985-01-01

    The study of the energy loss of high energy muons through different materials, such as rock and sea-water can cast light on characteristics of lepton interactions. There are less ambiguities for the values of atomic number (Z) and mass number (A) in sea-water than in rock. Muon intensities should be measured as fundamental data and as background data for searching the fluxes of neutrino. The average range energy relation in sea-water is derived. The correction factors due to the range fluctuation is also computed. By applying these results, the intensities deep under sea are converted from a given muon energy spectra at sea-level. The spectra of conventional muons from eta, K decays have sec theta enhancement. The spectrum of prompt muons from charmed particles is almost isotropic. The effect of prompt muons is examined.

  10. Stopping rate of negative cosmic-ray muons near sea level.

    NASA Technical Reports Server (NTRS)

    Spannagel, G.; Fireman, E. L.

    1972-01-01

    A relatively simple method for measuring with high sensitivity the rate of stopped negative muons is described. A process in which Ar-37 is obtained from K-39 in connection with the stopping of a negative muon was used in the experiments. The Ar-37 activity can be measured in small proportional counters with extremely low backgrounds. It is possible to remove Ar-37 from potassium acetate powder at room temperature with almost 100 per cent efficiency merely by trapping the gas from the storage container with a charcoal trap at the liquid nitrogen temperature.

  11. Relationship of sea level muon charge ratio to primary composition including nuclear target effects

    NASA Technical Reports Server (NTRS)

    Goned, A.; Shalaby, M.; Salem, A. M.; Roushdy, M.

    1985-01-01

    The discrepancy between the muon charge ratio observed at low energies and that calculated using pp data is removed by including nuclear target effects. Calculations at high energies show that the primary iron spectrum is expected to change slope from 2 to 2.2 to 2.4 to 2.5 for energies approx. 4 x 10 to the 3 GeV/nucleon if scaling features continue to the highest energies.

  12. Feasibility of Sea-level Cosmic-Ray Muon-Capture SNM Detection

    SciTech Connect

    Rosenberg, L; Bernstein, A

    2005-03-11

    The first part of this report argues the average time between signal events for X-rays from negative muon capture on SNM is from a few to a few 10's of minutes, depending on how sophisticated one care's to make the detector. The second part of this report argues that the recoil proton background in the energy resolution window can be orders of magnitude larger than the expected signal. How could one evade this result? Firstly, one could conceive of a very highly segmented muon counter (or electromagnetic calorimeter) system to actually detect a stopping muon. This would be extraordinarily expensive for a large area and volume of a cargo container. There are also quite a few assumptions we applied to make the calculations tractable. For instance, we assumed the detector was fully efficient for a neutron recoil. probably something like 25% or 50% is more appropriate. However, probably the biggest uncertainty is the neutron energy spectrum. The Boehm et al. paper discusses the range of spectrum parameterizations, some of which are considerably softer and will lower the high-energy proton yield. This outcome is certainly possible. However, given the difference between signal and background rates, it would take a considerable change in detector parameters and particle yields to change the basic conclusion that this technique does not appear promising.

  13. Study of muons near shower cores at sea level using the E594 neutrino detector

    NASA Technical Reports Server (NTRS)

    Goodman, J. A.; Gupta, S. C.; Freudenreich, H.; Sivaprasad, K.; Tonwar, S. C.; Yodh, G. B.; Ellsworth, R. W.; Goodman, M. C.; Bogert, D.; Burnstein, R.

    1985-01-01

    The E594 neutrino detector has been used to study the lateral distribution of muons of energy 3 GeV near shower cores. The detector consists of a 340 ton fine grain calorimeter with 400,000 cells of flash chamber and dimensions of 3.7 m x 20 m x 3.7 m (height). The average density in the calorimeter is 1.4 gm/sq cm, and the average Z is 21. The detector was triggered by four 0.6 sq m scintillators placed immediately on the top of the calorimeter. The trigger required at least two of these four counters. The accompanying extensive air showers (EAS) was sampled by 14 scintillation counters located up to 15 m from the calorimeter. Several off line cuts have been applied to the data. Demanding five particles in at least two of the trigger detectors, a total of 20 particles in all of them together, and an arrival angle for the shower 450 deg reduced the data sample to 11053 events. Of these in 4869 cases, a computer algorithm found at least three muons in the calorimeter.

  14. The composition of cosmic rays near the Bend (10 to the 15th power eV) from a study of muons in air showers at sea level

    NASA Technical Reports Server (NTRS)

    Goodman, J. A.; Gupta, S. C.; Freudenreich, H. T.; Sivaprasad, K.; Tonwar, S. C.; Yodh, G. B.; Ellsworth, R. W.; Goodman, M. C.; Bogert, M. C.; Burnstein, R.

    1985-01-01

    The distribution of muons near shower cores was studied at sea level at Fermilab using the E594 neutrino detector to sample the muon with E testing 3 GeV. These data are compared with detailed Monte Carlo simulations to derive conclusions about the composition of cosmic rays near the bend in the all particle spectrum. Monte Carlo simulations generating extensive air showers (EAS) with primary energy in excess of 50 TeV are described. Each shower record contains details of the electron lateral distribution and the muon and hadron lateral distributions as a function of energy, at the observation level of 100g/cm. The number of detected electrons and muons in each case was determined by a Poisson fluctuation of the number incident. The resultant predicted distribution of muons, electrons, the rate events are compared to those observed. Preliminary results on the rate favor a heavy primary dominated cosmic ray spectrum in energy range 50 to 1000 TeV.

  15. Analytic representation of the proton-proton and proton-nucleus cross-sections and its application to the sea-level spectrum and charge ratio of muons

    NASA Technical Reports Server (NTRS)

    Badhwar, G. D.; Golden, R. L.; Stephens, S. A.

    1977-01-01

    We have calculated the sea-level differential muon momentum spectrum and their charge ratio from 1 GeV/c to 5000 GeV/c, using all of the available accelerator data. We find an excellent agreement between our calculation and the existing experimental data. We see no need, at present, to invoke any change either in the cosmic-ray chemical composition or in the nature of the hadron-nucleus interaction at hadron energies above 1500 GeV.

  16. Estimation of sea level muon energy spectra in the energy range 0.2 GeV TO 10 GeV

    NASA Astrophysics Data System (ADS)

    Haldar, T. K.; Mitra, M.; Bhattacharyya, D. P.

    The vertical muon energy spectrum has been calculated in the energy range 0.2 GeV to 10 GeV using the latest directly measured primary cosmic ray nucleon spectrum . The primary cosmic ray nucleon spectrum has been calculated from the available measurements JACEE, CRN, SOKOL and the experiments done by Ramaty, Ryan, Seo, Badhwar on P, He, CNO, Ne -Si and Fe. Then using the superposition model the all nucleon spectrum has been constructed which makes the form N(E)dE = 1.13E-2.61 dE [cm2 .s.sr.GeV/n]-1 The pT integrated Lorentz invariant crosssections available from the CERN LEBC EHS data for π± and K± production initiated by pp collisions has been fitted and then from the fitting parameters hadronic energy moments have been calculated. The adopted inelastic crosssection for pp interactions is 35 mb and the value of σp-air cross-section has been adopted as 273 mb.The Z-factors have been corrected for p-air collisions using the methodology of Minorikawa and Mitsui. The Q-G plasma correction of Z-factors has also been made. Adopting the methodology of Arnon Dar and taking the other interaction parameters the modified production co-efficients gNM AT M have been calculated. To calculate the muon flux in this methode one has to estimate Cπ and CK for which we used the parametric values like Bπ = 1, BK = 0.632, pa = 2.3424, αK = 1.048.Using those values, Cπ and CK have been found out to be 0.220137 and 0.007149 respectively. The survival probability of muons which are produced at atmospheric depth λ0 to survive down to atmospheric depth l has been calculated with the help of the average muon production depth λ0 = 100 gm-cm-2 and survival depth λF = 1033 gmcm-2 , respectively. The energy loss of muon during its propagation through atmosphere has been calculated. Finally the vertical muon energy spectrum at sea level from conventinal meson decay has been estimated and compared with experimental data of CAPRICE-94 (1999), Allkofer et al.(1976), Allkofer et al. (1971

  17. Muon Excess at Sea Level during the Progress of a Geomagnetic Storm and High-Speed Stream Impact Near the Time of Earth's Heliospheric Sheet Crossing

    NASA Astrophysics Data System (ADS)

    Augusto, C. R. A.; Navia, C. E.; de Oliveira, M. N.; Nepomuceno, A. A.; Kopenkin, V.; Sinzi, T.

    2017-08-01

    In this article we present results of studying the association between the muon flux variation at ground level, registered by the New-Tupi muon telescopes (22° 53'00'' S, 43° 06'13' W; 3 m above sea level), and the geomagnetic storm on 25 - 29 August 2015 that has raged for several days as a result of a coronal mass ejection (CME) impact on Earth's magnetosphere. A sequence of events started with an M3.5 X-ray class flare on 22 August 2015 at 21:19 UTC. The New-Tupi muon telescopes observed a Forbush decrease (FD) triggered by this geomagnetic storm, which began on 26 August 2015. After Earth crossed the heliospheric current sheet (HCS), an increase in particle flux was observed on 28 August 2015 by spacecraft and ground-level detectors. The observed peak was in temporal coincidence with the impact of a high-speed stream (HSS). We study this increase, which has been observed with a significance above 1.5% by ground-level detectors in different rigidity regimes. We also estimate the lower limit of the energy fluence injected on Earth. In addition, we consider the origin of this increase, such as acceleration of particles by shock waves at the front of the HSS and the focusing effect of the HCS crossing. Our results show possible evidence of a prolonged energetic (up to GeV energies) particle injection within the Earth atmosphere system, driven by the HSS. In most cases, these injected particles are directed to the polar regions. However, the particles from the high-energy tail of the spectrum can reach mid-latitudes, and this could have consequences for the atmospheric chemistry. For instance, the creation of NOx species may be enhanced, and this can lead to increased ozone depletion. This topic requires further study.

  18. Absolute spectrum and charge ratio of cosmic ray muons in the energy region from 0.2 GeV to 100 GeV at 600 m above sea level

    NASA Technical Reports Server (NTRS)

    De Pascale, M. P.; Morselli, A.; Picozza, P.; Golden, R. L.; Grimani, C.; Kimbell, B. L.; Stephens, S. A.; Stochaj, S. J.; Webber, W. R.; Basini, G.

    1993-01-01

    We have determined the momentum spectrum and charge ratio of muons in the region from 250 MeV/c to 100 GeV/c using a superconducting magnetic spectrometer. The absolute differential spectrum of muons obtained in this experiment at 600 m above sea level is in good agreement with the previous measurements at sea level. The differential spectrum can be represented by a power law with a varying index, which is consistent with zero below 450 MeV/c and steepens to a value of -2.7 +/- 0.1 between 20 and 100 GeV/c. The integral f1ux of muons measured in this experiment span a very large range of momentum and is in excellent agreement with the earlier results. The positive to negative muon ratio appears to be constant in the entire momentum range covered in this experiment within the errors and the mean value is 1.220 +/- 0.044. The absolute momentum spectrum and the charge ratio measured in this experiment are also consistent with the theoretical expectations. This is the only experiment which covers a wide range of nearly three decades in momentum from a very low momentum.

  19. Underwater measurements of muon intensity

    NASA Technical Reports Server (NTRS)

    Fedorov, V. M.; Pustovetov, V. P.; Trubkin, Y. A.; Kirilenkov, A. V.

    1985-01-01

    Experimental measurements of cosmic ray muon intensity deep underwater aimed at determining a muon absorption curve are of considerable interest, as they allow to reproduce independently the muon energy spectrum at sea level. The comparison of the muon absorption curve in sea water with that in rock makes it possible to determine muon energy losses caused by nuclear interactions. The data available on muon absorption in water and that in rock are not equivalent. Underground measurements are numerous and have been carried out down to the depth of approx. 15km w.e., whereas underwater muon intensity have been measured twice and only down to approx. 3km deep.

  20. Longitudinal development of muons in large air showers studies from the arrival time distributions measured at 900m above sea level

    NASA Technical Reports Server (NTRS)

    Kakimoto, F.; Tsuchimoto, I.; Enoki, T.; Suga, K.; Nishi, K.

    1985-01-01

    The arrival time distributions of muons with energies above 1.0GeV and 0.5GeV have been measured 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.

  1. The PHENIX Muon Trigger Upgrade Level-1 Trigger System

    NASA Astrophysics Data System (ADS)

    Lajoie, John; Kempel, Todd

    2010-02-01

    The PHENIX Muon Trigger Upgrade adds a set of Level-1 trigger detectors to the existing muon spectrometers and will enhance the ability of the experiment to pursue a rich program of spin physics in polarized proton collisions. The upgrade will allow the experiment to select high momentum muons from the decay of W bosons and reject both beam-associated and low-momentum collision background, enabling the study of quark and antiquark polarization in the proton. The Muon Trigger Upgrade will add momentum and timing information to the present muon Level-1 trigger, which only makes use of tracking in the PHENIX muon identifier (MuID) panels. Signals from new Resistive Plate Chambers (RPCs) and re-instrumented planes in the existing muon tracking (MuTr) chambers will provide momentum and timing information for the new Level-1 trigger. An RPC timing resolution of ˜2 ns will permit rejection of beam related backgrounds while tracking information from the RPCs and MuTr station will be used by the trigger to select events with high momentum muon candidates. The RPC and MuTr hit information will be sent by optical fibers to a set of Level-1 trigger processors that will make use of cutting edge FPGA technology to provide very high data densities in a compact form factor. The layout of the upgrade, details of the Level-1 electronics and trigger algorithm development will be presented. )

  2. Muon Simulation at the Daya Bay SIte

    SciTech Connect

    Mengyun, Guan; Jun, Cao; Changgen, Yang; Yaxuan, Sun; Luk, Kam-Biu

    2006-05-23

    With a pretty good-resolution mountain profile, we simulated the underground muon background at the Daya Bay site. To get the sea-level muon flux parameterization, a modification to the standard Gaisser's formula was introduced according to the world muon data. MUSIC code was used to transport muon through the mountain rock. To deploy the simulation, first we generate a statistic sample of sea-level muon events according to the sea-level muon flux distribution formula; then calculate the slant depth of muon passing through the mountain using an interpolation method based on the digitized data of the mountain; finally transport muons through rock to get underground muon sample, from which we can get results of muon flux, mean energy, energy distribution and angular distribution.

  3. Deficit of the calculated muon flux at sea level for E{sub {mu}} {>=} 100 GeV: Analysis of possible reasons

    SciTech Connect

    Lagutin, A. A. Tyumentsev, A. G. Yushkov, A. V.

    2006-02-15

    The reasons why a deficit of the calculated muon flux for E{sub {mu}} {>=} 100 GeV arises if use is made of data from direct measurements of the spectra of primary cosmic rays and present-day nuclear-interaction models are considered. It is shown that this problem may stem from significantly underestimating the primary-nucleon flux in balloon-borne experiments employing the technique of emulsion chambers. This procedure relies on an extrapolation of accelerator data; therefore, it is necessary to estimate, on the basis of various Reggeon models of hadron interactions, the systematic error introduced by this circumstance in the results of the measurements. Such an analysis would make it possible to refine the behavior of the spectra of primary cosmic rays, to reduce the methodological part of the error in the calculation of the fluxes of secondary cosmic rays in the atmosphere, and to draw more precise conclusions on the flaws in present-day interaction models without invoking new accelerator data.

  4. Measurement of Ground Level Muon Charge Ratio Using ECRS Simulation

    NASA Astrophysics Data System (ADS)

    Sanjeewa, Hakmana; He, Xiaochun; Cleven, Christopher

    2006-11-01

    The Muon charge ratio at the Earth's surface has been studied with a Geant4 based simulation for two different geomagnetic locations: Atlanta and Lynn Lake. The simulation results are shown in excellent agreement with the data from NMSU-WIZARD/CAPRICE and BESS experiments at Lynn Lake, At low momentum, ground level muon charge ratios show latitude dependent geomagnetic effects for both Atlanta and Lynn Lake from the simulation. The simulated charge ratio is 1.20 ± 0.05 (without geomagnetic field), 1.12 ± 0.05 (with geomagnetic field) for Atlanta and 1.22 ± 0.04 (with geomagnetic field) for Lynn Lake. These types of studies are very important for analyzing secondary cosmic ray muon flux distribution at Earth's surface and can be used to evaluate the parameter of atmospheric neutrino oscillations.

  5. The Level-1 Tile-Muon Trigger in the Tile Calorimeter upgrade program

    NASA Astrophysics Data System (ADS)

    Ryzhov, A.

    2016-12-01

    The Tile Calorimeter (TileCal) is the central hadronic calorimeter of the ATLAS experiment at the Large Hadron Collider (LHC). TileCal provides highly-segmented energy measurements for incident particles. Information from TileCal's outermost radial layer can assist in muon tagging in the Level-1 Muon Trigger by rejecting fake muon triggers due to slow charged particles (typically protons) without degrading the efficiency of the trigger. The main activity of the Tile-Muon Trigger in the ATLAS Phase-0 upgrade program was to install and to activate the TileCal signal processor module for providing trigger inputs to the Level-1 Muon Trigger. This report describes the Tile-Muon Trigger, focusing on the new detector electronics such as the Tile Muon Digitizer Board (TMDB) that receives, digitizes and then provides the signal from eight TileCal modules to three Level-1 muon endcap Sector-Logic Boards.

  6. 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.

  7. 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

  8. 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

  9. 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.

  10. 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.

  11. 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

  12. Effect of copper and aluminium on the event rate of cosmic ray muons at ground level in Bangi, Malaysia

    NASA Astrophysics Data System (ADS)

    Altameemi, Rasha N. I.; Gopir, G.

    2016-11-01

    In this study we determine the effect of aluminium (Al) and copper (Cu) shielding on the event rate of cosmic ray muons at ground level. The experiment was performed at Bangi in Malaysia with coordinates of 101.78° E, 2.92° N and elevation 30 m above sea level. Measurements were made along the vertical direction using muon telescopes (MTs) of parallel Geiger-Muller (GM) tubes with metal sheets above the MTs of up to 2.4 cm for Al and 2.7 cm for Cu. For these ranges of metal thicknesses, we find that the muon count rates increase linearly with the increase in metal thicknesses. The observed increase rate values are (0.18 ± 0.10) cm-1 and (0.26 ± 0.10)cm-1 for Al and Cu, respectively, with the larger value for Cu as expected from its higher atomic number and density. This indicates that for this thickness range, only the lower region of the Rossi curve is observed, with incoming cosmic ray muons producing charged particles in the metal layers, resulting in shower events or electromagnetic cascade. Thus, for this range of layer thickness, both aluminium and copper are not suitable to be used as shielding materials for ground level cosmic ray muons.

  13. 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

  14. 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.

  15. 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.

  16. Muon simulations for Super-Kamiokande, KamLAND, and CHOOZ

    SciTech Connect

    Tang, Alfred; Horton-Smith, Glenn; Kudryavtsev, Vitaly A.; Tonazzo, Alessandra

    2006-09-01

    Muon backgrounds at Super-Kamiokande, KamLAND, and CHOOZ are calculated using MUSIC. A modified version of the Gaisser sea-level muon distribution and a well-tested Monte Carlo integration method are introduced. Average muon energy, flux, and rate are tabulated. Plots of average energy and angular distributions are given. Implications for muon tracker design in future experiments are discussed.

  17. A Monte Carlo Calculation of Muon Flux at Ground Level from Primary Cosmic Gamma Rays

    SciTech Connect

    Fasso, Alberto

    1999-08-27

    The Monte Carlo program FLUKA was used to calculate the number of muons reaching detection level in events initiated by primary cosmic gamma ray interactions in the atmosphere. The calculation was motivated by the desire to gauge the sensitivity of arrays like that of Project GRAND to primary gamma cosmic rays while measuring single muons at detection level. Because direct gamma pair production is not a significant source of muons, normally the presence of muons is not considered as a signal for gamma rays. However, due to their non-negligible cross section for hadron production, high-energy gamma rays can initiate hadronic showers containing a large number of pions. These can decay producing secondary muons which then have a good chance of reaching detection level. The complete kinetic energy and space distribution of such muons can be predicted by simulating in detail the whole process by means of Monte Carlo techniques. However, the code used must be capable of handling both hadron-nucleus and photon-nucleus interactions. Unlike most available Monte Carlo particle transport programs, such interactions are implemented in FLUKA, up to several tens of TeV, based on Dual Parton and Vector Meson Dominance models. The FLUKA capability to describe hadronic cascades generated in the atmosphere by primary cosmic hadrons has already been shown in several studies. In the present paper, the investigation has been extended to primary gamma rays. The number of muons per photon is presented as a function of the primary energy in the region between 3 GeV and 10 TeV. As the energy of primary photons rises, their flux falls, whereas the number of muons per gamma rises. Combining these two effects, it can be predicted that gamma ray energies in the 30 GeV region produce the most muons at detection level. The radial and kinetic energy distributions of the muons are also presented.

  18. Muon level-crossing resonance in antiferromagnetic MnF/sub 2/

    SciTech Connect

    Kiefl, R.F.; Luke, G.M.; Kreitzman, S.R.; Celio, M.; Keitel, R.; Brewer, J.H.; Noakes, D.R.; Uemura, Y.J.; Portis, A.M.; Jaccarino, V.; and others

    1987-02-01

    We report the observation of a muon-nuclear level-crossing resonance (LCR) in the antiferromagnet MnF/sub 2/. The resonance occurs when the spin transition frequency of an interstitial muon is matched to that of the nearest-neighbor /sup 19/F nuclei, allowing for a resonant transfer of polarization from the muon to the nuclei. The applied external field H/sub 0/ at which the LCR occurs is a measure of the local magnetic field on the neighboring /sup 19/F nuclei. The observed shift relative to earlier /sup 19/F NMR results is attributed to the disturbing influence of the muon. A second resonance was observed when H/sub 0/ cancels the longitudinal component of the local field at the muon.

  19. Sea level extremes in the Caribbean Sea

    NASA Astrophysics Data System (ADS)

    Torres, R. Ricardo; Tsimplis, Michael N.

    2014-08-01

    Sea level extremes in the Caribbean Sea are analyzed on the basis of hourly records from 13 tide gauges. The largest sea level extreme observed is 83 cm at Port Spain. The largest nontidal residual in the records is 76 cm, forced by a category 5 hurricane. Storm surges in the Caribbean are primarily caused by tropical storms and stationary cold fronts intruding the basin. However, the seasonal signal and mesoscale eddies also contribute to the creation of extremes. The five stations that have more than 20 years of data show significant trends in the extremes suggesting that flooding events are expected to become more frequent in the future. The observed trends in extremes are caused by mean sea level rise. There is no evidence of secular changes in the storm activity. Sea level return periods have also been estimated. In the south Colombian Basin, where large hurricane-induced surges are rare, stable estimates can be obtained with 30 years of data or more. For the north of the basin, where large hurricane-induced surges are more frequent, at least 40 years of data are required. This suggests that the present data set is not sufficiently long for robust estimates of return periods. ENSO variability correlates with the nontidal extremes, indicating a reduction of the storm activity during positive ENSO events. The period with the highest extremes is around October, when the various sea level contributors' maxima coincide.

  20. 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.

  1. 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

  2. Sea Level Rise Data Discovery

    NASA Astrophysics Data System (ADS)

    Quach, N.; Huang, T.; Boening, C.; Gill, K. M.

    2016-12-01

    Research related to sea level rise crosses multiple disciplines from sea ice to land hydrology. The NASA Sea Level Change Portal (SLCP) is a one-stop source for current sea level change information and data, including interactive tools for accessing and viewing regional data, a virtual dashboard of sea level indicators, and ongoing updates through a suite of editorial products that include content articles, graphics, videos, and animations. The architecture behind the SLCP makes it possible to integrate web content and data relevant to sea level change that are archived across various data centers as well as new data generated by sea level change principal investigators. The Extensible Data Gateway Environment (EDGE) is incorporated into the SLCP architecture to provide a unified platform for web content and science data discovery. EDGE is a data integration platform designed to facilitate high-performance geospatial data discovery and access with the ability to support multi-metadata standard specifications. EDGE has the capability to retrieve data from one or more sources and package the resulting sets into a single response to the requestor. With this unified endpoint, the Data Analysis Tool that is available on the SLCP can retrieve dataset and granule level metadata as well as perform geospatial search on the data. This talk focuses on the architecture that makes it possible to seamlessly integrate and enable discovery of disparate data relevant to sea level rise.

  3. Energy deposition study of low-energy cosmic radiation at sea level

    NASA Astrophysics Data System (ADS)

    Wijesinghe, Pushpa

    In this dissertation work, a computer simulation model based on the Geant4 simulation package has been designed and developed to study the energy deposition and track structures of cosmic muons and their secondary electrons in tissue-like materials. The particle interactions in a cubic water volume were first simulated. To analyze the energy deposition and tracks in small structures, with the intention of studying the energy localization in nanometric structures such as DNA, the chamber was sliced in three dimentions. Validation studies have been performed by comparing the results with experimental, theoretical, and other simulation results to test the accuracy of the simulation model. A human body phantom in sea-level muon environment was modeled to measure the yearly dose to a human from cosmic muons. The yearly dose in this phantom is about 22 millirems. This is close to the accepted value for the yearly dose from cosmic radiation at sea level. Shielding cosmic muons with a concrete slab from 0 to 2 meters increased the dose received by the body. This dissertation presents an extensive study on the interactions of secondary electrons created by muons in water. Index words. Radiation Dosimetry Simulation, Track Structures, Sea-Level muon Flux, Energy Deposition

  4. Observation of a level crossing in a molecular nanomagnet using implanted muons.

    PubMed

    Lancaster, T; Möller, J S; Blundell, S J; Pratt, F L; Baker, P J; Guidi, T; Timco, G A; Winpenny, R E P

    2011-06-22

    We have observed an electronic energy level crossing in a molecular nanomagnet (MNM) using muon spin relaxation. This effect, not observed previously despite several muon studies of MNM systems, provides further evidence that the spin relaxation of the implanted muon is sensitive to the dynamics of the electronic spin. Our measurements on a broken ring MNM [H(2)N(t)Bu(is)Pr][Cr(8)CdF(9)(O(2)CC(CH(3))(3))(18)], which contains eight Cr ions, show clear evidence for the S = 0 --> S = 1 transition that takes place at B(c) = 2.3 T. The crossing is observed as a resonance-like dip in the average positron asymmetry and also in the muon spin relaxation rate, which shows a sharp increase in magnitude at the transition and a peak centred within the S = 1 regime.

  5. 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.

  6. 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.

  7. Using Neural Networks to Detect Di-muon Tracks for Fermilab E906/SeaQuest

    NASA Astrophysics Data System (ADS)

    Carstens, Paul; SeaQuest Collaboration

    2015-10-01

    The experiment E906/SeaQuest aims to gain further insight into the nucleon quark sea by gathering information about the anti-down/anti-up ratio produced by Drell-Yan events. SeaQuest collides a 120 GeV proton beam with one of several targets, liquid hydrogen, liquid deuterium, carbon, tungsten, iron, and two calibration targets, empty target and no target. The di-muon pairs created by the Drell-Yan events are monitored by four detector stations. Each has a set of hodoscopes, stations one, two, and three have wire chambers, and station four, which has a lower resolution, has a set of prop tubes. In order to separate the useful Drell-Yan events from dump events and background noise we employ the use of the hodoscopes to trigger potentially useful events to keep. This neural network would learn to properly discern Drell-Yan events by associating hodoscope readings from real data with results from existing trigger systems. By doing this, we could efficiently replicate existing results while alleviating the processing needed. This work is supported by U.S. DOE MENP Grant DE-FG02-03ER41243.

  8. Muon reconstruction and selection at the last trigger level of the ATLAS experiment

    NASA Astrophysics Data System (ADS)

    Crupi, R.

    2010-04-01

    The three-level Trigger and DAQ system of ATLAS is designed to be very selective while preserving the full physics potential of the experiment; out of the ~1 GHz of p-p interactions provided by the LHC at nominal operating conditions, ~200 events/sec are retained. This paper focuses on the muon reconstruction and selection algorithms employed at the last trigger level. One implements an "outside-in" approach; it starts from a reconstruction in the Muon Spectrometer (MS) and performs a backward extrapolation to the interaction point and track combination in the Inner Detector (ID). The other implements an "inside-out" strategy; it starts muon reconstruction from the ID and extrapolates tracks to MS. Algorithm implementations and results on data from real cosmic rays and simulated collisions are described.

  9. NEW APPROACHES: Measurement of the mean lifetime of cosmic ray muons in the A-level laboratory

    NASA Astrophysics Data System (ADS)

    Dunne, Peter; Costich, David; O'Sullivan, Sean

    1998-09-01

    The Turning Points in Physics module from the NEAB A-level Modular Physics syllabus requires students to have an understanding of relativistic time dilation and offers the measurement of the mean lifetime of cosmic ray muons as an example of supporting experimental evidence. This article describes a direct measurement of muon lifetime carried out in the A-level laboratory.

  10. The Gran Sasso muon puzzle

    SciTech Connect

    Fernandez-Martinez, Enrique; Mahbubani, Rakhi E-mail: rakhi@cern.ch

    2012-07-01

    We carry out a time-series analysis of the combined data from three experiments measuring the cosmic muon flux at the Gran Sasso laboratory, at a depth of 3800 m.w.e. These data, taken by the MACRO, LVD and Borexino experiments, span a period of over 20 years, and correspond to muons with a threshold energy, at sea level, of around 1.3 TeV. We compare the best-fit period and phase of the full muon data set with the combined DAMA/NaI and DAMA/LIBRA data, which spans the same time period, as a test of the hypothesis that the cosmic ray muon flux is responsible for the annual modulation detected by DAMA. We find in the muon data a large-amplitude fluctuation with a period of around one year, and a phase that is incompatible with that of the DAMA modulation at 5.2σ. Aside from this annual variation, the muon data also contains a further significant modulation with a period between 10 and 11 years and a power well above the 99.9% C.L threshold for noise, whose phase corresponds well with the solar cycle: a surprising observation for such high energy muons. We do not see this same period in the stratospheric temperature data.

  11. Glaciers and Sea Level Rise

    NASA Image and Video Library

    2017-09-28

    This ice cave in Belcher Glacier (Devon Island, Canada) was formed by melt water flowing within the glacier ice. To learn about the contributions of glaciers to sea level rise, visit: www.nasa.gov/topics/earth/features/glacier-sea-rise.html Credit: Angus Duncan, University of Saskatchewan NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

  12. Glaciers and Sea Level Rise

    NASA Image and Video Library

    2017-09-28

    Melt water ponded at surface in the accumulation zone of Columbia Glacier, Alaska, in July 2008. To learn about the contributions of glaciers to sea level rise, visit: www.nasa.gov/topics/earth/features/glacier-sea-rise.html Credit: W. Tad Pfeffer, University of Colorado at Boulder NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

  13. Glaciers and Sea Level Rise

    NASA Image and Video Library

    2017-09-28

    Summit camp on top of the Austfonna Ice Cap in Svalbard (Norwegian Arctic). To learn about the contributions of glaciers to sea level rise, visit: www.nasa.gov/topics/earth/features/glacier-sea-rise.html Credit: Thorben Dunse, University of Oslo NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

  14. Glaciers and Sea Level Rise

    NASA Image and Video Library

    2007-05-17

    Small valley glacier exiting the Devon Island Ice Cap in Canada. To learn about the contributions of glaciers to sea level rise, visit: http://www.nasa.gov/topics/earth/features/glacier-sea-rise.html Credit: Alex Gardner, Clark University NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

  15. Effective Sea-level Cosmic Ray Exposure of Copper During Transportation

    NASA Astrophysics Data System (ADS)

    Berguson, Timothy; Orrell, John; Aguayo, Estanislao; Greene, Austen

    2012-10-01

    The Majorana Project aims to observe neutrinoless double beta decay utilizing high purity germanium detectors enclosed in a low-background shield. Germanium and copper, which are to be used in the detector assembly, are susceptible to cosmogenic activation, which produces isotopes within the materials whose decay generates signals in the energy region of interest of neutrinoless double beta decay, thus serving as an unwanted background. In order to assure that the materials have not been exposed to cosmic radiation beyond the established acceptable limits, a muon detector, the Muon-Witness, was used to track the integral muon count rate. This muon rate can be used to estimate the activation levels of the materials relative to the cosmic background at sea level. Other Majorana collaborators have previously estimated the activation using another method, and the two results varied significantly. An analysis of the two methods, including simulations and measurements with the Muon-Witness checking for its efficiency to muons, seeks to understand this discrepancy.

  16. 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.

  17. Glaciers and Sea Level Rise

    NASA Image and Video Library

    2017-09-27

    Calving front of the Perito Moreno Glacier (Argentina). Contrary to the majority of the glaciers from the southern Patagonian ice field, the Perito Moreno Glacier is currently stable. It is also one of the most visited glaciers in the world. To learn about the contributions of glaciers to sea level rise, visit: www.nasa.gov/topics/earth/features/glacier-sea-rise.html Credit: Etienne Berthier, Université de Toulouse NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

  18. Glaciers and Sea Level Rise

    NASA Image and Video Library

    2017-09-27

    Calving front of the Upsala Glacier (Argentina). This glacier has been thinning and retreating at a rapid rate during the last decades – from 2006 to 2010, it receded 43.7 yards (40 meters) per year. During summer 2012, large calving events prevented boat access to the glacier. To learn about the contributions of glaciers to sea level rise, visit: www.nasa.gov/topics/earth/features/glacier-sea-rise.html Credit: Etienne Berthier, Université de Toulouse NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

  19. Glaciers and Sea Level Rise

    NASA Image and Video Library

    2017-09-28

    Peripheral glaciers and ice caps (isolated from the main ice sheet, which is seen in the upper right section of the image) in eastern Greenland. To learn about the contributions of glaciers to sea level rise, visit: www.nasa.gov/topics/earth/features/glacier-sea-rise.html Credit: Frank Paul, University of Zurich NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

  20. Glaciers and Sea Level Rise

    NASA Image and Video Library

    2017-09-28

    The Aletsch Glacier in Switzerland is the largest valley glacier in the Alps. Its volume loss since the middle of the 19th century is well-visible from the trimlines to the right of the image. To learn about the contributions of glaciers to sea level rise, visit: www.nasa.gov/topics/earth/features/glacier-sea-rise.html Credit: Frank Paul, University of Zurich NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

  1. Glaciers and Sea Level Rise

    NASA Image and Video Library

    2017-09-27

    An airplane drops essential support on the Austfonna Ice Cap in Svalbard (Norwegian Arctic). The triangular structure is a corner reflector used as ground reference for airborne radar surveys. To learn about the contributions of glaciers to sea level rise, visit: www.nasa.gov/topics/earth/features/glacier-sea-rise.html Credit: Andrea Taurisano, Norwegian Polar Institute NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

  2. Glaciers and Sea Level Rise

    NASA Image and Video Library

    2013-01-01

    Calving front of the Perito Moreno Glacier (Argentina). Contrary to the majority of the glaciers from the southern Patagonian ice field, the Perito Moreno Glacier is currently stable. It is also one of the most visited glaciers in the world. To learn about the contributions of glaciers to sea level rise, visit: http://www.nasa.gov/topics/earth/features/glacier-sea-rise.html Credit: Etienne Berthier, Université de Toulouse NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

  3. Glaciers and Sea Level Rise

    NASA Image and Video Library

    2008-08-25

    Aerial view of the Sverdrup Glacier, a river of ice that flows from the interior of the Devon Island Ice Cap (Canada) into the ocean. To learn about the contributions of glaciers to sea level rise, visit: http://www.nasa.gov/topics/earth/features/glacier-sea-rise.html Credit: Alex Gardner, Clark University NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

  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. Upgrade of the Muon Sorter in the Cathode Strip Chamber Level 1 Trigger System at CMS

    NASA Astrophysics Data System (ADS)

    Acosta, D.; Ecklund, K.; Furic, I.; Liu, J.; Madorsky, A.; Matveev, M.; Padley, P.

    2013-11-01

    The top level of the Level 1 Trigger System in the Cathode Strip Chamber (CSC) detector at CMS consists of the Track Finder (TF) crate with 12 Sector Processors (SP) and one Muon Sorter (MS) board. The MS provides sorting of up to 36 trigger objects from the SP boards, selects the four best (by a definable criterion) ones, and transmits then to the Global Trigger crate of CMS. With the anticipated LHC luminosity increase above 1034 cm-2s-1 at an energy of 6.5-7 TeV/beam the CSC TF needs to be upgraded. The new CSCTF will be robust to higher occupancies, provide improved transverse momentum assignment and increased precision of the muon output variables. A transition from the current 9U VME electronic standard to the more flexible uTCA and utilization of the Xilinx Virtex-6 and Virtex-7 FPGAs, with multiple embedded gigabit links, will allow us to build a higher performance TF such that the MS functions can be performed by one of the SP modules. We present here the results of our efforts in the past year to upgrade the CSC Muon Sorter, including the short term modifications of the existing VME board, long-term transition to the uTCA as well as firmware development for both of these projects.

  6. Range fluctuations of high energy muons passing through matter

    NASA Technical Reports Server (NTRS)

    Minorikawa, Y.; Mitsui, K.

    1985-01-01

    The information about energy spectrum of sea level muons at high energies beyond magnetic spectrographs can be obtained from the underground intensity measurements if the fluctuations problems are solved. The correction factor R for the range fluctuations of high energy muons were calculated by analytical method of Zatsepin, where most probable energy loss parameter are used. It is shown that by using the R at great depth together with the slope, lambda, of the vertical depth-intensity (D-I) curve in the form of exp(-t/lambda), the spectral index, gamma, in the power law energy spectrum of muons at sea level can be obtained.

  7. 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.

  8. Plastic scintillators in coincidence for the study of multi-particle production of sea level cosmic rays in dense medium

    NASA Technical Reports Server (NTRS)

    Chuang, L. S.; Chan, K. W.; Wada, M.

    1985-01-01

    Cosmic ray particles at sea level penetrate a thick layer of dense medium without appreciable interaction. These penetrating particles are identified with muons. The only appreciable interaction of muons are by knock on processes. A muon may have single, double or any number of knock on with atoms of the material so that one, two, three or more particles will come out from the medium in which the knock on processes occur. The probability of multiparticle production is expected to decrease with the increase of multiplicity. Measurements of the single, double, and triple particles generated in a dense medium (Fe and Al) by sea level cosmic rays at 22.42 N. Lat. and 114.20 E. Long. (Hong Kong) are presented using a detector composed of two plastic scintillators connected in coincidence.

  9. Cosmogenic Chlorine-36 Production in Calcite by Muons

    NASA Astrophysics Data System (ADS)

    Stone, J. O. H.; Evans, J. M.; Fifield, L. K.; Allan, G. L.; Cresswell, R. G.

    1998-02-01

    At depths below a few metres, 36Cl production in calcite is initiated almost entirely by cosmic ray muons. The principal reactions are (1) direct negative muon capture by Ca; 40Ca(μ -,α) 36Cl, and (2) capture by 35Cl of secondary neutrons produced in muon capture and muon-induced photodisintegration reactions. We have determined rates for 36Cl and neutron production due to muon capture in calcite from a 20 m (5360 g cm -2) depth profile in limestone. The 36Cl yield from muon capture by Ca in pure calcite is 0.012 ± 0.002 atom per stopped negative muon. The surface production rate of 36Cl by muon capture on Ca in calcite is, therefore, 2.1 ± 0.4 atom g -1a -1 at sea level and high latitude, approximately 11% of the production rate by Ca spallation. If it is assumed that 34% of the negative muons are captured by the Ca atom in calcite, the α-yield from 40Ca following muon capture is 0.043 ± 0.008, somewhat lower than the result of a recent muon irradiation experiment (0.062 ± 0.020), but well within the extremes of existing theoretical predictions (0.0033-0.15). The average neutron yield following muon capture in pure calcite is 0.44 ± 0.15 secondary neutrons per stopped negative muon, in good agreement with existing theoretical predictions. Cosmogenic isotope production by muons must be taken into account when dating young geomorphic surfaces, especially those created by excavation of only a few metres of overlying rock. Attention to isotope production by muons is also crucial to determining surface erosion rates accurately. Due to the deep penetration of muons compared to cosmic ray hadrons, the accumulation of muon-produced 36Cl is less sensitive to erosion than that of spallogenic 36Cl. Although production by muons at the surface is only a small fraction of production by spallation, the fraction of muon-produced 36Cl in rapidly eroding limestone surfaces can approach 50%. In such cases, erosion rates estimated using conventional models which attribute

  10. Borehole Muon Detector Development

    NASA Astrophysics Data System (ADS)

    Bonneville, A.; Flygare, J.; Kouzes, R.; Lintereur, A.; Yamaoka, J. A. K.; Varner, G. S.

    2015-12-01

    Increasing atmospheric CO2 concentrations have spurred investigation into carbon sequestration methods. One of the possibilities being considered, storing super-critical CO2 in underground reservoirs, has drawn more attention and pilot projects are being supported worldwide. Monitoring of the post-injection fate of CO2 is of utmost importance. Generally, monitoring options are active methods, such as 4D seismic reflection or pressure measurements in monitoring wells. We propose here to develop a 4-D density tomography of subsurface CO2 reservoirs using cosmic-ray muon detectors deployed in a borehole. Muon detection is a relatively mature field of particle physics and there are many muon detector designs, though most are quite large and not designed for subsurface measurements. The primary technical challenge preventing deployment of this technology in the subsurface is the lack of miniaturized muon-tracking detectors capable of fitting in standard boreholes and that will resist the harsh underground conditions. A detector with these capabilities is being developed by a collaboration supported by the U.S. Department of Energy. Current simulations based on a Monte Carlo modeling code predict that the incoming muon angle can be resolved with an error of approximately two degrees, using either underground or sea level spectra. The robustness of the design comes primarily from the use of scintillating rods as opposed to drift tubes. The rods are arrayed in alternating layers to provide a coordinate scheme. Preliminary testing and measurements are currently being performed to test and enhance the performance of the scintillating rods, in both a laboratory and a shallow underground facility. The simulation predictions and data from the experiments will be presented.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Energy spectrum of cascades generated by muons in Baksan underground scintillation telescope

    NASA Technical Reports Server (NTRS)

    Bakatanov, V. N.; Chudakov, A. E.; Novoseltsev, Y. F.; Novoseltseva, M. V.; Achkasov, V. M.; Semenov, A. M.; Stenkin, Y. V.

    1985-01-01

    Spectrum of cascades generated by cosmic ray muons underground is presented. The mean zenith angle of the muon arrival is theta=35 deg the depth approx. 1000 hg/sq cm. In cascades energy range 700 GeV the measured spectrum is in agreement with the sea-level integral muon spectrum index gamma=3.0. Some decrease of this exponent has been found in the range 4000 Gev.

  16. NOAA Regional Sea Level Trends and Scenarios

    NASA Astrophysics Data System (ADS)

    Sweet, W.; Zervas, C.; Leuliette, E. W.

    2016-12-01

    NOAA has a new website to help coastal communities recognize past changes in regional sea level to better plan for a range of possible rise scenarios this century. The site compares 11 regionalized and coherent tide-gauge and satellite-altimeter sea level series from around the U.S. to estimate multi-decadal changes that have occurred in response to regional sea surface height-related trends and variability. Local relative trends are obtainable even without data from a local tide gauge when combined with estimates of vertical land motion, which can be obtained from several years of record from a GPS-based continuously operating reference system (CORS). The regionalized series will be updated annually and displayed relative to the most recent sea level rise scenarios of the (i.e., 2014) National Climate Assessment to characterize the regional sea level change trajectory for future planning of associated impacts.

  17. 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

  18. Difference of sea level rising rate from steric and altimeter sea level in the regional Yellow and East China Seas

    NASA Astrophysics Data System (ADS)

    Kang, S. K.; Cherniawsky, J. Y.; Foreman, M. G. G.; Kim, E.

    2016-12-01

    Regional sea level rise is examined in the Yellow and East China Seas (YECS) for the Topex/Poseidon and Jason altimetry period. Coastal tidal data, altimetry and steric sea level data are examined and compared from 1993 to 2015. As usual, temperature and salinity data sampled at regular intervals are available for only a limited number of stations around the Korean Peninsula. The regional sea level rising rate from altimetry compares well with the sea level rising rate from coastal sea level data around Korean Peninsula and Japanese islands around the YECS where data are available. However, differences between the sea level rising rate from altimetry and the steric sea level rising rate are rather large, as expected, since mass effects can not be reflected in the steric sea level rising rate. This is significantly different from the results of the sea level rising trend in the deep East/Japan Sea where thermosteric sea level compares well with the altimetry sea level trend during 9 year period from 1992 to 2001 (Kang et al., 2005). This may suggest that the cause of variability in sea level rising may change with the global trend change in sea level rise with increasing melting effect.The difference of steric sea level and altimetry data for the last 23 years (1993-2015) is expected to be mainly due to mass effects or the addition of mass and dynamic effects. The limited number of data from CTD stations may cause inaccuracies in estimating regional steric sea level in the YECS. The steric sea level rising rate computed from Argo data in the northwestern Pacific (D. Roemmich, 2013), upstream of East China Sea, seems to indicate a negative steric sea level rising pattern during 2006-2013. This suggests that water characteristics affecting the East China Seas through the Kuroshio may contribute to a negative sea level rising trend. More discussion will be given during the meeting.This work is partially supported from research funds from KIOST project (PE99392).

  19. 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.

  20. Electronics for CMS Endcap Muon Level-1 Trigger System Phase-1 and HL LHC upgrades

    NASA Astrophysics Data System (ADS)

    Madorsky, A.

    2017-07-01

    To accommodate high-luminosity LHC operation at a 13 TeV collision energy, the CMS Endcap Muon Level-1 Trigger system had to be significantly modified. To provide robust track reconstruction, the trigger system must now import all available trigger primitives generated by the Cathode Strip Chambers and by certain other subsystems, such as Resistive Plate Chambers (RPC). In addition to massive input bandwidth, this also required significant increase in logic and memory resources. To satisfy these requirements, a new Sector Processor unit has been designed. It consists of three modules. The Core Logic module houses the large FPGA that contains the track-finding logic and multi-gigabit serial links for data exchange. The Optical module contains optical receivers and transmitters; it communicates with the Core Logic module via a custom backplane section. The Pt Lookup table (PTLUT) module contains 1 GB of low-latency memory that is used to assign the final Pt to reconstructed muon tracks. The μ TCA architecture (adopted by CMS) was used for this design. The talk presents the details of the hardware and firmware design of the production system based on Xilinx Virtex-7 FPGA family. The next round of LHC and CMS upgrades starts in 2019, followed by a major High-Luminosity (HL) LHC upgrade starting in 2024. In the course of these upgrades, new Gas Electron Multiplier (GEM) detectors and more RPC chambers will be added to the Endcap Muon system. In order to keep up with all these changes, a new Advanced Processor unit is being designed. This device will be based on Xilinx UltraScale+ FPGAs. It will be able to accommodate up to 100 serial links with bit rates of up to 25 Gb/s, and provide up to 2.5 times more logic resources than the device used currently. The amount of PTLUT memory will be significantly increased to provide more flexibility for the Pt assignment algorithm. The talk presents preliminary details of the hardware design program.

  1. Atmospheric Muon Lifetime, Standard Model of Particles and the Lead Stopping Power for Muons

    NASA Astrophysics Data System (ADS)

    Gutarra-Leon, Angel; Barazandeh, Cioli; Majewski, Walerian

    2017-01-01

    The muon is a fundamental particles of matter. It decays into three other leptons through an exchange of the weak vector bosons W +/W-. Muons are present in the atmosphere from cosmic ray showers. By detecting the time delay between arrival of the muon and an appearance of the decay electron in our detector, we'll measure muon's lifetime at rest. From the lifetime we should be able to find the ratio gw /MW of the weak coupling constant gw (a weak analog of the electric charge) to the mass of the W-boson MW. Vacuum expectation value v of the Higg's field, which determines the masses of all particles of the Standard Model (SM), could be then calculated from our muon experiment as v =2MWc2/gw =(τ m μc2/6 π3ĥ)1/4m μc2 in terms of muon mass mµand muon lifetime τ only. Using known experimental value for MWc2 = 80.4 GeV we'll find the weak coupling constant gw. Using the SM relation e =gwsin θ√ hc ɛ0 with the experimental value of the Z0-photon weak mixing angle θ = 29o we could find from our muon lifetime the value of the elementary electric charge e. We'll determine the sea-level fluxes of low-energy and high-energy cosmic muons, then we'll shield the detector with varying thicknesses of lead plates and find the energy-dependent muon stopping power in lead.

  2. 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.

  3. 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

  4. Mangrove dieback during fluctuating sea levels.

    PubMed

    Lovelock, Catherine E; Feller, Ilka C; Reef, Ruth; Hickey, Sharyn; Ball, Marilyn C

    2017-05-10

    Recent evidence indicates that climate change and intensification of the El Niño Southern Oscillation (ENSO) has increased variation in sea level. Although widespread impacts on intertidal ecosystems are anticipated to arise from the sea level seesaw associated with climate change, none have yet been demonstrated. Intertidal ecosystems, including mangrove forests are among those ecosystems that are highly vulnerable to sea level rise, but they may also be vulnerable to sea level variability and extreme low sea level events. During 16 years of monitoring of a mangrove forest in Mangrove Bay in north Western Australia, we documented two forest dieback events, the most recent one being coincident with the large-scale dieback of mangroves in the Gulf of Carpentaria in northern Australia. Diebacks in Mangrove Bay were coincident with periods of very low sea level, which were associated with increased soil salinization of 20-30% above pre-event levels, leading to canopy loss, reduced Normalized Difference Vegetation Index (NDVI) and reduced recruitment. Our study indicates that an intensification of ENSO will have negative effects on some mangrove forests in parts of the Indo-Pacific that will exacerbate other pressures.

  5. 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.

  6. 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.

  7. 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)

  8. 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

  9. Vulnerability of marginal seas to sea level rise

    NASA Astrophysics Data System (ADS)

    Gomis, Damia; Jordà, Gabriel

    2017-04-01

    Sea level rise (SLR) is a serious thread for coastal areas and has a potential negative impact on society and economy. SLR can lead for instance to land loss, beach reduction, increase of the damage of marine storms on coastal infrastructures and to the salinization of underground water streams. It is well acknowledged that future SLR will be inhomogeneous across the globe, with regional differences of up to 100% with respect to global mean sea level (GMSL). Several studies have addressed the projections of SLR at regional scale, but most of them are based on global climate models (GCMs) that have a relatively coarse spatial resolution (>1°). In marginal seas this has proven to be a strong limitation, as their particular configurations require spatial resolutions that are not reachable by present GCMs. A paradigmatic case is the Mediterranean Sea, connected to the global ocean through the Strait of Gibraltar, a narrow passage of 14 km width. The functioning of the Mediterranean Sea involves a variety of processes including an overturning circulation, small-scale convection and a rich mesoscale field. Moreover, the long-term evolution of Mediterranean sea level has been significantly different from the global mean during the last decades. The observations of present climate and the projections for the next decades have lead some authors to hypothesize that the particular characteristics of the basin could allow Mediterranean mean sea level to evolve differently from the global mean. Assessing this point is essential to undertake proper adaptation strategies for the largely populated Mediterranean coastal areas. In this work we apply a new approach that combines regional and global projections to analyse future SLR. In a first step we focus on the quantification of the expected departures of future Mediterranean sea level from GMSL evolution and on the contribution of different processes to these departures. As a result we find that, in spite of its particularities

  10. 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.

  11. 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

  12. 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

  13. Bayesian Prediction and Projection of Sea Levels

    NASA Astrophysics Data System (ADS)

    Berliner, M.

    2014-12-01

    I will begin with a brief review of Bayesian hierarchical modeling and then turn to a model for sea levels. It is well-accepted that global sea levels have been rising in response to rising global temperatures. The strategy is the development of a Bayesian hierarchical model of sea levels. The hierarchical nature of the model is formulated to enable inference at various spatial scales. Further, temperature is incorporated in the model as a predictor or explanatory variable. Hence, information regarding future sea levels provided by the model rely on information regarding future temperatures. Forming predictions of future temperatures can be done in severalways, depending on the goals of the analysis. I consider two classes of goals. In the first we seek short-term or medium-range forecasts as in weather-like forecasting. In the second we seek projections of sea levels under various emissions scenarios as in studies of the impacts of climate change. I illustrate methods and results for each class and suggest how results can contribute to decision support.

  14. 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.

  15. 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..

  16. 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.

  17. Sea level changes in the holocene

    NASA Astrophysics Data System (ADS)

    Kidson, C.

    Over the last 30 years the emphasis in studies of the recovery from low last glaciation sea levels has changed significantly. The search for a eustatic sea level curve having global relevance has ended. Studies into the rheology of the earth's crust, and recognition that the geoid has not remained stable over time, have resulted in the recognition that there must have been regional differences in eustatic response to deglaciation. As a part of this re-appraisal there has been a growing appreciation that crustal isostatic response to the removal of the weight of ice sheets has been accompanied by a consequential hydro-isostatic response, particularly in the areas of the shelf seas. In the later part of the post-war period attention has additionally been focussed on the much greater potential for error over the whole field of palaeoenvironmental reconstruction in the Holocene, including not only errors in dating, but also a large number of possible sources of errors in heighting. As a result of this, an increasing number of scientists are withholding judgement on the nature of sea level rise and, more particularly, on the problem of higher than present late Holocene eustatic sea levels. The problems outstanding in the early 1960s have not yet been resolved but the bases of uncertainty have changed.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. The Atmospheric Muon Lifetime, with the Lead Absorption Potential for Muons and References to the Standard Model of Particle Physics

    NASA Astrophysics Data System (ADS)

    Barazandeh, Cioli; Gutarra-Leon, Angel; Majewski, Walerian

    2017-01-01

    Muon is one of twelve fundamental particles and has the longest free-particle lifetime. It decays into three leptons through an exchange of weak vector bosons W +/W-. Muons are present in atmospheric secondary cosmic rays and reach the sea level. By detecting the time delay between arrival of muons and appearance of decay electrons in a scintillation detector, we will measure muon's lifetime at rest. From the lifetime we can find the ratio gw /MW of the weak coupling constant gw (a weak analog of the electric charge) to mass of the W-boson MW. Vacuum expectation value v of the Higgs field, which determines masses Standard Model (SM) particles, can be calculated as v =2MWc2/gw =(τmμc2/6π3\\hcirc)1/4mμc2 regarding muon mass mμ and muon lifetime τ only. Using the experimental value for MWc2 = 80.4 GeV, we will find weak coupling constant gw. With the SM relation e =gwsin θ√ hcε0 and experimental value of the Z0-photon weak mixing angle θ = 29o we use our muon lifetime to find the elementary electric charge e value. In this experiment we will also determine the sea level fluxes of low-energy (<160 MeV) and high-energy cosmic muons, then will shield the detector with varying thicknesses of lead plates and from the new values of fluxes find the energy-dependent muon stopping power in lead.

  5. 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.

  6. 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…

  7. Annotated Bibliography of Relative Sea Level Change

    DTIC Science & Technology

    1991-09-01

    Quaternary sea-level changes. Former studies of Tasmanian Quaternary shorelines assumed that stable or quasi-stable tectonic conditions prevailed (Lewis...that moved through Devils Hole-- an open fault zone at Ash Meadows, Nevada--between 50 and 310 ka (thousand years ago). The configuration of the versus

  8. 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)

  9. 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)

  10. 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...

  11. 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...

  12. 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…

  13. Analysis of Sea Level Rise in Action

    NASA Astrophysics Data System (ADS)

    Gill, K. M.; Huang, T.; Quach, N. T.; Boening, C.

    2016-12-01

    NASA's Sea Level Change Portal provides scientists and the general public with "one-stop" source for current sea level change information and data. Sea Level Rise research is a multidisciplinary research and in order to understand its causes, scientists must be able to access different measurements and to be able to compare them. The portal includes an interactive tool, called the Data Analysis Tool (DAT), for accessing, visualizing, and analyzing observations and models relevant to the study of Sea Level Rise. Using NEXUS, an open source, big data analytic technology developed at the Jet Propulsion Laboratory, the DAT is able provide user on-the-fly data analysis on all relevant parameters. DAT is composed of three major components: A dedicated instance of OnEarth (a WMTS service), NEXUS deep data analytic platform, and the JPL Common Mapping Client (CMC) for web browser based user interface (UI). Utilizing the global imagery, a user is capable of browsing the data in a visual manner and isolate areas of interest for further study. The interfaces "Analysis" tool provides tools for area or point selection, single and/or comparative dataset selection, and a range of options, algorithms, and plotting. This analysis component utilizes the Nexus cloud computing platform to provide on-demand processing of the data within the user-selected parameters and immediate display of the results. A RESTful web API is exposed for users comfortable with other interfaces and who may want to take advantage of the cloud computing capabilities. This talk discuss how DAT enables on-the-fly sea level research. The talk will introduce the DAT with an end-to-end tour of the tool with exploration and animating of available imagery, a demonstration of comparative analysis and plotting, and how to share and export data along with images for use in publications/presentations. The session will cover what kind of data is available, what kind of analysis is possible, and what are the outputs.

  14. 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

  15. 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.

  16. Inconsistencies in sea level pressure trends between different atmospheric products. Impact on sea level trend estimation

    NASA Astrophysics Data System (ADS)

    Gomis, D.; Jordà, G.

    2012-04-01

    Long term climate datasets are of great importance to understand the processes behind climate variability, to evaluate the performance of climate models and to identify signals of climate change. Among the different atmospheric variables, sea level pressure (SLP) is the basic dynamical variable and is the most widely analyzed quantity. From the ocean perspective, SLP is of crucial importance for a dynamical interpretation of sea level records. In order to isolate the contribution to sea level variability of circulation and heat and freshwater contents, a common practice is to remove the sea level fluctuations induced by SLP. At seasonal and longer time scales, sea level is expected to react as an inverted barometer (IB) to changes in SLP. Therefore, provided that accuracy of available SLP data is high enough, the atmospheric contribution to sea level variability can be isolated and removed from sea level records. This is routinely done for tide gauge records, altimetry or sea level reconstructions. Different atmospheric gridded products spanning the last decades are nowadays available. On the one hand, there are historical SLP datasets where observations from land stations and ocean observations have been interpolated into a regular grid. On the other hand, there are reanalyses where an atmospheric model is run assimilating the historical data. Both kind of products have been extensively used in recent years either directly (i.e. to analyse the SLP evolution) or indirectly (i.e. through the removal of IB effect on sea level records). However, it is well known that the quality of those products may not be homogeneous on time. In this contribution, we compare long term SLP trends from different atmospheric products (reanalysis and gridded historical datasets), and evaluate the uncertainties introduced by them in the sea level trend estimations. The results show that discrepancies between datasets can induce an uncertainty up to 0.5 mm/yr for the period 1958-2001 on

  17. 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

  18. 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

  19. DUACS: Toward High Resolution Sea Level Products

    NASA Astrophysics Data System (ADS)

    Faugere, Y.; Gerald, D.; Ubelmann, C.; Claire, D.; Pujol, M. I.; Antoine, D.; Desjonqueres, J. D.; Picot, N.

    2016-12-01

    The DUACS system produces, as part of the CNES/SALP project, and the Copernicus Marine Environment and Monitoring Service, high quality multimission altimetry Sea Level products for oceanographic applications, climate forecasting centers, geophysic and biology communities... These products consist in directly usable and easy to manipulate Level 3 (along-track cross-calibrated SLA) and Level 4 products (multiple sensors merged as maps or time series) and are available in global and regional version (Mediterranean Sea, Arctic, European Shelves …).The quality of the products is today limited by the altimeter technology "Low Resolution Mode" (LRM), and the lack of available observations. The launch of 2 new satellites in 2016, Jason-3 and Sentinel-3A, opens new perspectives. Using the global Synthetic Aperture Radar mode (SARM) coverage of S3A and optimizing the LRM altimeter processing (retracking, editing, ...) will allow us to fully exploit the fine-scale content of the altimetric missions. Thanks to this increase of real time altimetry observations we will also be able to improve Level-4 products by combining these new Level-3 products and new mapping methodology, such as dynamic interpolation. Finally these improvements will benefit to downstream products : geostrophic currents, Lagrangian products, eddy atlas… Overcoming all these challenges will provide major upgrades of Sea Level products to better fulfill user needs.

  20. 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

  1. 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.

  2. Consequences of sea level variability and sea level rise for Cuban territory

    NASA Astrophysics Data System (ADS)

    Hernández, M.; Martínez, C. A.; Marzo, O.

    2015-03-01

    The objective of the present paper was to determine a first approximation of coastal zone flooding by 2100, taking into account the more persistent processes of sea level variability and non-accelerated linear sea level rise estimation to assess the main impacts. The annual linear rate of mean sea level rise in the Cuban archipelago, obtained from the longest tide gauge records, has fluctuated between 0.005 cm/year at Casilda and 0.214 cm/year at Siboney. The main sea level rise effects for the Cuban coastal zone due to climate change and global warming are shown. Monthly and annual mean sea level anomalies, some of which are similar to or higher than the mean sea level rise estimated for halfway through the present century, reinforce the inland seawater penetration due to the semi-daily high tide. The combination of these different events will result in the loss of goods and services, and require expensive investments for adaption.

  3. 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. 

  4. 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.

  5. 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).

  6. 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…

  7. 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…

  8. Cosmic-muon intensity measurement and overburden estimation in a building at surface level and in an underground facility using two BC408 scintillation detectors coincidence counting system.

    PubMed

    Zhang, Weihua; Ungar, Kurt; Liu, Chuanlei; Mailhot, Maverick

    2016-10-01

    A series of measurements have been recently conducted to determine the cosmic-muon intensities and attenuation factors at various indoor and underground locations for a gamma spectrometer. For this purpose, a digital coincidence spectrometer was developed by using two BC408 plastic scintillation detectors and an XIA LLC Digital Gamma Finder (DGF)/Pixie-4 software and card package. The results indicate that the overburden in the building at surface level absorbs a large part of cosmic ray protons while attenuating the cosmic-muon intensity by 20-50%. The underground facility has the largest overburden of 39 m water equivalent, where the cosmic-muon intensity is reduced by a factor of 6. The study provides a cosmic-muon intensity measurement and overburden assessment, which are important parameters for analysing the background of an HPGe counting system, or for comparing the background of similar systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. 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.

  10. 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.

  11. Muon colliders

    SciTech Connect

    Palmer, R.B. |; Sessler, A.; Skrinsky, A.

    1996-01-01

    Muon Colliders have unique technical and physics advantages and disadvantages when compared with both hadron and electron machines. They should thus be regarded as complementary. Parameters are given of 4 TeV and 0.5 TeV high luminosity {micro}{sup +}{micro}{sup {minus}}colliders, and of a 0.5 TeV lower luminosity demonstration machine. We discuss the various systems in such muon colliders, starting from the proton accelerator needed to generate the muons and proceeding through muon cooling, acceleration and storage in a collider ring. Problems of detector background are also discussed.

  12. Muon colliders

    NASA Astrophysics Data System (ADS)

    Palmer, R. B.; Sessler, A.; Skrinsky, A.; Tollestrup, A.; Baltz, A. J.; Chen, P.; Cheng, W.-H.; Cho, Y.; Courant, E.; Fernow, R. C.; Gallardo, J. C.; Garren, A.; Green, M.; Kahn, S.; Kirk, H.; Lee, Y. Y.; Mills, F.; Mokhov, N.; Morgan, G.; Neuffer, D.; Noble, R.; Norem, J.; Popovic, M.; Schachinger, L.; Silvestrov, G.; Summers, D.; Stumer, I.; Syphers, M.; Torun, Y.; Trbojevic, D.; Turner, W.; Van Ginneken, A.; Vsevolozhskaya, T.; Weggel, R.; Willen, E.; Winn, D.; Wurtele, J.

    1996-05-01

    Muon Colliders have unique technical and physics advantages and disadvantages when compared with both hadron and electron machines. They should thus be regarded as complementary. Parameters are given of 4 TeV and 0.5 TeV high luminosity μ+μ- colliders, and of a 0.5 TeV lower luminosity demonstration machine. We discuss the various systems in such muon colliders, starting from the proton accelerator needed to generate the muons and proceeding through muon cooling, acceleration and storage in a collider ring. Problems of detector background are also discussed.

  13. Sea level forecasts using neural networks

    NASA Astrophysics Data System (ADS)

    Röske, Frank

    1997-03-01

    In this paper, a new method for predicting the sea level employing a neural network approach is introduced. It was designed to improve the prediction of the sea level along the German North Sea Coast under standard conditions. The sea level at any given time depends upon the tides as well as meteorological and oceanographic factors, such as the winds and external surges induced by air pressure. Since tidal predictions are already sufficiently accurate, they have been subtracted from the observed sea levels. The differences will be predicted up to 18 hours in advance. In this paper, the differences are called anomalies. The prediction of the sea level each hour is distinguished from its predictions at the times of high and low tide. For this study, Cuxhaven was selected as a reference site. The predictions made using neural networks were compared for accuracy with the prognoses prepared using six models: two hydrodynamic models, a statistical model, a nearest neighbor model, which is based on analogies, the persistence model, and the verbal forecasts that are broadcast and kept on record by the Sea Level Forecast Service of the Federal Maritime and Hydrography Agency (BSH) in Hamburg. Predictions were calculated for the year 1993 and compared with the actual levels measured. Artificial neural networks are capable of learning. By applying them to the prediction of sea levels, learning from past events has been attempted. It was also attempted to make the experiences of expert forecasters objective. Instead of using the wide-spread back-propagation networks, the self-organizing feature map of Kohonen, or “Kohonen network”, was applied. The fundamental principle of this network is the transformation of the signal similarity into the neighborhood of the neurons while preserving the topology of the signal space. The self-organization procedure of Kohonen networks can be visualized. To make predictions, these networks have been subdivided into a part describing the

  14. Past Sea Level Reconstruction and Variability of Sea Level Trend Patterns over 1958-2005 in the Mediterranean Sea basin

    NASA Astrophysics Data System (ADS)

    Meyssignac, B.; Cazenave, A. A.; Morrow, R. A.; Llovel, W.; Maisongrande, P.; Fenoglio-Marc, L.

    2009-12-01

    For the past decades, there are no direct basin-scale observations informing on the spatial trend patterns in Mediterranean sea level. Yet it is important to know the dominant modes of regional variability on interannual/decadal/multidecadal time scale in the Mediterranean basin and their driving mechanisms. For that purpose, we have developed a reconstruction method of past Mediterranean sea level (since 1958) that combines long tide gauge records of limited coverage and 2-D sea level patterns based on runs from two different Ocean General Circulation Models (OGCMs). Instead of using 2-D spatial patterns from satellite altimetry (as done in previous studies; e.g., Calafat et al., 2009), here we prefer to use OGCM runs on the past few decades on the assumption that they better capture the decadal variability of the spatial trend patterns. The two OGCMs considered are the ORCA05 run (without data assimilation) over 1958-2005 available from the DRAKKAR project and the SODA reanalyse over 1958-2005 available from GODAE (Carton et al., 2008), assimilating all available in situ temperature, salinity and sea level data. The two sea level reconstructions are compared to each other as well as with previous studies (e.g., Calafat et al., 2009). The dominant modes of temporal variability are discussed and sea level hindcasts at tide gauge sites not used in the analysis are compared to actual observations. Comparisons with steric sea level patterns based on in situ hydrographic data are also presented and discussed with regard to the conclusions of past studies based on tide gauge records analysis.

  15. Sea-level transitioning dual bell nozzles

    NASA Astrophysics Data System (ADS)

    Stark, Ralf; Génin, Chloé

    2017-09-01

    A detailed study was conducted to evaluate the impact of sea-level transitioning dual bell nozzles on the payload mass delivered into geostationary transfer orbit by Ariane 5 ECA. For this purpose, a multitude of Vulcain 2 and Vulcain 2.1 nozzle extension contours were designed. The two variable parameters were the position of the wall inflection and the constant wall pressure of the nozzle extension. Accounting for the two variable parameters, an approved analytical method was applied to predict the impact of the dual bell nozzles on the payload mass.

  16. Towards data-driven regional sea level projections

    NASA Astrophysics Data System (ADS)

    Larson, J.; Nerem, R. S.; Landerer, F. W.; Hamlington, B.

    2016-12-01

    Sea level change will be one of the greatest environmental challenges facing society in the coming century. Projecting future regional sea level change remains a challenge due to the underlying complexity of the Earth system. The standard method for projecting sea level relies on physics-based, global climate models. While these models are robust, they fail to account for processes and feedbacks that we do not yet fully understand, such as ocean-driven mass loss at ice sheet margins. To account for uncertainty in the underlying physics of the climate system, an alternative, observation-driven modeling approach can be taken. One increasingly popular observation driven model, referred to as the semi-empirical method, combines statistical relationships between past climate observations with physical constraints to understand how sea level has responded to global temperature in the past. This knowledge can then be combined with global temperature projections to forecast sea level forward in time. The semi-empirical method has been successfully applied to global mean sea level but has never been used to project regional sea level change, which can differ significantly from the global average. However, a regional approach requires developing separate semi-empirical models for each component of sea level change. Here we use historic sea level data and sea level fingerprint models to push the semi-empirical method into the regional domain to better project sea level along the coasts.

  17. 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.

  18. Influence of Sea Level Rise on the Dynamics of Salt Inflows in the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Hordoir, R.; Axell, L.; Löptien, U.; Dietze, H.; Kuznetsov, I.

    2016-02-01

    The Baltic Sea is a marginal sea, located in a highly industrialized region in Central Northern Europe.Salt water inflows from the North Sea and associated ventilation of the deep exert crucial control on the entire Baltic Sea ecosystem.This study explores the impact of anticipated sea level changes on the dynamics of those inflows. We usea numerical oceanic general circulation model covering both the Baltic andthe North Sea. The model sucessfully retraces the essential ventilation dynamicsthroughout the period 1961 to 2007. A suite of idealized experiments suggests thatrising sea level is associated with intensified ventilation as salt water inflowsbecome stronger, longer and more frequent. Expressed quantitatively as a salinityincrease in the deep central Baltic Sea we find that a sea level rise of 1 m triggers asaltening of more than 1 PSU. This substantial increase in ventilation is theconsequence of the increasing cross section in the Danish Straits amplified bya reduction of vertical mixing.

  19. Deglacial sea level history of the East Siberian Sea and Chukchi Sea margins

    NASA Astrophysics Data System (ADS)

    Cronin, Thomas M.; O'Regan, Matt; Pearce, Christof; Gemery, Laura; Toomey, Michael; Semiletov, Igor; Jakobsson, Martin

    2017-09-01

    Deglacial (12.8-10.7 ka) sea level history on the East Siberian continental shelf and upper continental slope was reconstructed using new geophysical records and sediment cores taken during Leg 2 of the 2014 SWERUS-C3 expedition. The focus of this study is two cores from Herald Canyon, piston core SWERUS-L2-4-PC1 (4-PC1) and multicore SWERUS-L2-4-MC1 (4-MC1), and a gravity core from an East Siberian Sea transect, SWERUS-L2-20-GC1 (20-GC1). Cores 4-PC1 and 20-GC were taken at 120 and 115 m of modern water depth, respectively, only a few meters above the global last glacial maximum (LGM; ˜ 24 kiloannum or ka) minimum sea level of ˜ 125-130 meters below sea level (m b.s.l.). Using calibrated radiocarbon ages mainly on molluscs for chronology and the ecology of benthic foraminifera and ostracode species to estimate paleodepths, the data reveal a dominance of river-proximal species during the early part of the Younger Dryas event (YD, Greenland Stadial GS-1) followed by a rise in river-intermediate species in the late Younger Dryas or the early Holocene (Preboreal) period. A rapid relative sea level rise beginning at roughly 11.4 to 10.8 ka ( ˜ 400 cm of core depth) is indicated by a sharp faunal change and unconformity or condensed zone of sedimentation. Regional sea level at this time was about 108 m b.s.l. at the 4-PC1 site and 102 m b.s.l. at 20-GC1. Regional sea level near the end of the YD was up to 42-47 m lower than predicted by geophysical models corrected for glacio-isostatic adjustment. This discrepancy could be explained by delayed isostatic adjustment caused by a greater volume and/or geographical extent of glacial-age land ice and/or ice shelves in the western Arctic Ocean and adjacent Siberian land areas.

  20. 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.

  1. 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.

  2. Long-term Caspian Sea level change

    NASA Astrophysics Data System (ADS)

    Chen, J. L.; Pekker, T.; Wilson, C. R.; Tapley, B. D.; Kostianoy, A. G.; Cretaux, J.-F.; Safarov, E. S.

    2017-07-01

    Caspian Sea level (CSL) has undergone substantial fluctuations during the past several hundred years. The causes over the entire historical period are uncertain, but we investigate here large changes seen in the past several decades. We use climate model-predicted precipitation (P), evaporation (E), and observed river runoff (R) to reconstruct long-term CSL changes for 1979-2015 and show that PER (P-E + R) flux predictions agree very well with observed CSL changes. The observed rapid CSL increase (about 12.74 cm/yr) and significant drop ( -6.72 cm/yr) during the periods 1979-1995 and 1996-2015 are well accounted for by integrated PER flux predictions of +12.38 and -6.79 cm/yr, respectively. We show that increased evaporation rates over the Caspian Sea play a dominant role in reversing the increasing trend in CSL during the past 37 years. The current long-term decline in CSL is expected to continue into the foreseeable future, under global warming scenarios.

  3. 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.

  4. 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

  5. Global sea level change: Determination and interpretation

    NASA Astrophysics Data System (ADS)

    Douglas, Bruce C.

    1995-07-01

    The notion of sea level rise brings to the popular mind the specter of deep inundation of coastal regions. One pictures skyscrapers emerging from the waters like so many sleeping flamingos standing in the shallows of a lake. Of course if all of the world's ice sheets suddenly melted or collapsed, this vision would apply to New York City and its coastal counterparts. But there is a general consensus that such a calamity is not an immediate threat [Houghton et al, 1990]. The actual situation for the recent historical past and near future appears to be more benign, but with nonetheless extremely significant, even devastating impacts due to erosion and flooding of coastal areas.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. Muon muon collider: Feasibility study

    SciTech Connect

    1996-06-18

    A feasibility study is presented of a 2 + 2 TeV muon collider with a luminosity of L = 10{sup 35} cm{sup {minus}2} s{sup {minus}1}. The resulting design is not optimized for performance, and certainly not for cost; however, it does suffice--the authors believe--to allow them to make a credible case, that a muon collider is a serious possibility for particle physics and, therefore, worthy of R and D support so that the reality of, and interest in, a muon collider can be better assayed. The goal of this support would be to completely assess the physics potential and to evaluate the cost and development of the necessary technology. The muon collider complex consists of components which first produce copious pions, then capture the pions and the resulting muons from their decay; this is followed by an ionization cooling channel to reduce the longitudinal and transverse emittance of the muon beam. The next stage is to accelerate the muons and, finally, inject them into a collider ring which has a small beta function at the colliding point. This is the first attempt at a point design and it will require further study and optimization. Experimental work will be needed to verify the validity of diverse crucial elements in the design.

  11. Partitioning of small amphiphiles at surfactant bilayer/water interfaces: an avoided level crossing muon spin resonance study.

    PubMed

    Scheuermann, Robert; Tucker, Ian M; Dilger, Herbert; Staples, Ed J; Ford, Gary; Fraser, Stuart B; Beck, Bettina; Roduner, Emil

    2004-03-30

    The temperature-dependent variation of local environment and reorientation dynamics of the small amphiphile 2-phenylethanol in lamellar phase dispersions of the dichain cationic surfactants, 2,3-diheptadecyl ester ethoxypropyl-1,1,1-trimethylammonium chloride (DHTAC) and dioctadecyldimethylammonium chloride (DODMAC), and the nonionic surfactant, tetra(ethylene glycol) n-dodecyl ether (C12E4), have been determined using avoided level crossing muon spin resonance spectroscopy (ALC-muSR). For cosurfactant radicals the hydrophobic or hydrophilic character of the surrounding media can be determined from their magnetic resonance signatures. Comparison of the three different bilayer-forming surfactant systems shows that the ALC-muSR technique is able to distinguish both major and subtle differences in the partitioning of the cosurfactant radicals between the different systems.

  12. A New Approach in Coal Mine Exploration Using Cosmic Ray Muons

    NASA Astrophysics Data System (ADS)

    Darijani, Reza; Negarestani, Ali; Rezaie, Mohammad Reza; Fatemi, Syed Jalil; Akhond, Ahmad

    2016-08-01

    Muon radiography is a technique that uses cosmic ray muons to image the interior of large scale geological structures. The muon absorption in matter is the most important parameter in cosmic ray muon radiography. Cosmic ray muon radiography is similar to X-ray radiography. The main aim in this survey is the simulation of the muon radiography for exploration of mines. So, the production source, tracking, and detection of cosmic ray muons were simulated by MCNPX code. For this purpose, the input data of the source card in MCNPX code were extracted from the muon energy spectrum at sea level. In addition, the other input data such as average density and thickness of layers that were used in this code are the measured data from Pabdana (Kerman, Iran) coal mines. The average thickness and density of these layers in the coal mines are from 2 to 4 m and 1.3 gr/c3, respectively. To increase the spatial resolution, a detector was placed inside the mountain. The results indicated that using this approach, the layers with minimum thickness about 2.5 m can be identified.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. New estimate of the current rate of sea level rise from a sea level budget approach

    NASA Astrophysics Data System (ADS)

    Dieng, H. B.; Cazenave, A.; Meyssignac, B.; Ablain, M.

    2017-04-01

    We revisit the global mean sea level (GMSL) budget during the whole altimetry era (January 1993 to December 2015) using a large number of data sets. The budget approach allows quantifying the TOPEX A altimeter drift (amounting 1.5 ± 0.5 mm/yr over 1993-1998). Accounting for this correction and using ensemble means for the GMSL and components lead to closure of the sea level budget (trend of the residual time series being 0.0 ± 0.22 mm/yr). The new GMSL rate over January 1993 to December 2015 is now close to 3.0 mm/yr. An important increase of the GMSL rate, of 0.8 mm/yr, is found during the second half of the altimetry era (2004-2015) compared to the 1993-2004 time span, mostly due to Greenland mass loss increase and also to slight increase of all other components of the budget.

  1. 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.

  2. 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.

  3. Ice-sheet and sea-level changes.

    PubMed

    Alley, Richard B; Clark, Peter U; Huybrechts, Philippe; Joughin, Ian

    2005-10-21

    Future sea-level rise is an important issue related to the continuing buildup of atmospheric greenhouse gas concentrations. The Greenland and Antarctic ice sheets, with the potential to raise sea level approximately 70 meters if completely melted, dominate uncertainties in projected sea-level change. Freshwater fluxes from these ice sheets also may affect oceanic circulation, contributing to climate change. Observational and modeling advances have reduced many uncertainties related to ice-sheet behavior, but recently detected, rapid ice-marginal changes contributing to sea-level rise may indicate greater ice-sheet sensitivity to warming than previously considered.

  4. Sea-level rise and its impact on coastal zones.

    PubMed

    Nicholls, Robert J; Cazenave, Anny

    2010-06-18

    Global sea levels have risen through the 20th century. These rises will almost certainly accelerate through the 21st century and beyond because of global warming, but their magnitude remains uncertain. Key uncertainties include the possible role of the Greenland and West Antarctic ice sheets and the amplitude of regional changes in sea level. In many areas, nonclimatic components of relative sea-level change (mainly subsidence) can also be locally appreciable. Although the impacts of sea-level rise are potentially large, the application and success of adaptation are large uncertainties that require more assessment and consideration.

  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. The Adriatic Sea: A Long-Standing Laboratory for Sea Level Studies

    NASA Astrophysics Data System (ADS)

    Vilibić, Ivica; Šepić, Jadranka; Pasarić, Mira; Orlić, Mirko

    2017-07-01

    The paper provides a comprehensive review of all aspects of Adriatic Sea level research covered by the literature. It discusses changes occurring over millennial timescales and documented by a variety of natural and man-made proxies and post-glacial rebound models; mean sea level changes occurring over centennial to annual timescales and measured by modern instruments; and daily and higher-frequency changes (with periods ranging from minutes to a day) that are contributing to sea level extremes and are relevant for present-day flooding of coastal areas. Special tribute is paid to the historic sea level studies that shaped modern sea level research in the Adriatic, followed by a discussion of existing in situ and remote sensing observing systems operating in the Adriatic area, operational forecasting systems for Adriatic storm surges, as well as warning systems for tsunamis and meteotsunamis. Projections and predictions of sea level and related hazards are also included in the review. Based on this review, open issues and research gaps in the Adriatic Sea level studies are identified, as well as the additional research efforts needed to fill the gaps. The Adriatic Sea, thus, remains a laboratory for coastal sea level studies for semi-enclosed, coastal and marginal seas in the world ocean.

  7. 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.

  8. Quantifying the impact of basin dynamics on the regional sea level rise in the Black Sea

    NASA Astrophysics Data System (ADS)

    Kubryakov, Arseny A.; Stanichny, Sergey V.; Volkov, Denis L.

    2017-06-01

    Satellite altimetry measurements show that the magnitude of the Black Sea sea level trends is spatially uneven. While the basin-mean sea level rise from 1993 to 2014 was about 3.15 mm yr-1, the local rates of sea level rise varied from 1.5-2.5 mm yr-1 in the central part to 3.5-3.8 mm yr-1 at the basin periphery and over the northwestern shelf and to 5 mm yr-1 in the southeastern part of the sea. We show that the observed spatial differences in the dynamic sea level (anomaly relative to the basin-mean) are caused by changes in the large- and mesoscale dynamics of the Black Sea. First, a long-term intensification of the cyclonic wind curl over the Black Sea, observed in 1993-2014, strengthened divergence in the center of the basin and led to the rise of the sea level in coastal and shelf areas and a lowering in the basin's interior. Second, an extension of the Batumi anticyclone to the west resulted in ˜ 1.2 mm yr-1 higher rates of sea level rise in the southeastern part of the sea. Further, we demonstrate that the large-scale dynamic sea level variability in the Black Sea can be successfully reconstructed using the wind curl obtained from an atmospheric reanalysis. This allows for the correction of historical tide gauge records for dynamic effects in order to derive more accurate estimates of the basin-mean sea level change in the past, prior to the satellite altimetry era.

  9. Climate variability, extremes and trends of total sea level variations of the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Lehmann, Andreas; Herrford, Josefine; Höflich, Katharina; Getzlaff, Klaus

    2017-04-01

    The total sea level change of the Baltic Sea is a combination of wind-driven large volume changes (LVCs), local sea level variations (water level raised by wind and seiche) and wind waves including the sea level change by climatic-driven water density changes and the global sea level rise. The ocean surface velocity is a combination of Ekman surface flow, baroclinic and barotropic flow components and Stokes drift. The first two components can be calculated by standard hydrodynamic 3-dimensional ocean circulation models. But the calculation of the Stokes drift needs an additional approach. The Stokes velocity is a function of the significant wave height and period. It is important for the generation of Langmuir circulation which in turn contributes to the vertical mixing near the ocean surface and to the wind-driven surface transport. We used the Kiel Baltic Sea ice-ocean model (BSIOM) coupled with a simple fully integrated wave model to determine total sea level changes of the entire Baltic Sea for the period 1979-2016. BSIOM has been forced by ERA-Interim reanalysis data (1979-2016). The coupled model system allows the calculation of the total sea level change on a 2.5 km model grid of the entire Baltic Sea as a combination of large volume changes (LVCs), local sea level variations and wind waves including the sea level rise due to climatic-driven water density changes. Thus, combining sea level changes of different time and space scales. Different areas of the Baltic Sea show different trends in significant wave heights over different seasons. During winter, an increase of significant wave height is mainly associated with the retreat of the sea ice cover. There is also an increase of significant wave height of about 5 cm/decade in the eastern Gotland basin during winter. In summer and autumn we found negative trends strongest in the south-western Baltic Sea. Extreme total sea level variations occur if LVCs coincide with local sea level variations and wind waves.

  10. Sea-level fluctuations during the last glacial cycle

    NASA Astrophysics Data System (ADS)

    Siddall, M.; Rohling, E. J.; Almogi-Labin, A.; Hemleben, Ch.; Meischner, D.; Schmelzer, I.; Smeed, D. A.

    2003-06-01

    The last glacial cycle was characterized by substantial millennial-scale climate fluctuations, but the extent of any associated changes in global sea level (or, equivalently, ice volume) remains elusive. Highstands of sea level can be reconstructed from dated fossil coral reef terraces, and these data are complemented by a compilation of global sea-level estimates based on deep-sea oxygen isotope ratios at millennial-scale resolution or higher. Records based on oxygen isotopes, however, contain uncertainties in the range of +/-30m, or +/-1°C in deep sea temperature. Here we analyse oxygen isotope records from Red Sea sediment cores to reconstruct the history of water residence times in the Red Sea. We then use a hydraulic model of the water exchange between the Red Sea and the world ocean to derive the sill depth-and hence global sea level-over the past 470,000 years (470kyr). Our reconstruction is accurate to within +/-12m, and gives a centennial-scale resolution from 70 to 25kyr before present. We find that sea-level changes of up to 35m, at rates of up to 2cmyr-1, occurred, coincident with abrupt changes in climate.

  11. Mean sea level determination from satellite altimetry

    NASA Technical Reports Server (NTRS)

    Kahn, W. D.; Agrawal, B. B.; Brown, R. D.

    1979-01-01

    The primary experiment on the Geodynamics Experimental Ocean Satellite-3 (GEOS-3) is the radar altimeter. This experiment's major objective is to demonstrate the utility of measuring the geometry of the ocean surface; i.e., the geoid. Results obtained from this experiment so far indicate that the planned objectives of measuring the topography of the ocean surface with an absolute accuracy of + or - 5 m can be met and perhaps exceeded. The GEOS-3 satellite altimeter measurements have an instrument precision in the range of + or - 25 cm to + or - 50 cm when the altimeter is operating in the 'short pulse' mode. After one year's operations of the altimeter, data from over 5000 altimeter passes have been collected. With the mathematical models developed and the altimeter data presently available, mapping of local areas of ocean topography has been realized to the planned accuracy levels and better. This paper presents the basic data processing methods employed and some interesting results achieved with the early data. Plots of mean sea surface heights as inferred by the altimeter measurements are compared with a detailed 1 by 1 deg gravimetric geoid.

  12. 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

  13. 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

  14. Inception of a global atlas of Holocene sea levels

    NASA Astrophysics Data System (ADS)

    Khan, Nicole; Rovere, Alessio; Engelhart, Simon; Horton, Benjamin

    2017-04-01

    Determining the rates, mechanisms and geographic variability of sea-level change is a priority science question for the next decade of ocean research. To address these research priorities, the HOLocene SEA-level variability (HOLSEA) working group is developing the first standardized global synthesis of Holocene relative sea-level data to: (1) estimate the magnitudes and rates of global mean sea-level change during the Holocene; and (2) identify trends in spatial variability and decipher the processes responsible for geographic differences in relative sea-level change. Here we present the preliminary efforts of the working group to compile the database, which includes sea-level index points and limiting data from a range of different indicators across seven continents from the Last Glacial Maximum to present. We follow a standard protocol that incorporates full consideration of vertical and temporal uncertainty for each sea-level index point, including uncertainties associated with the relationship of each indicator to past sea-level and the methods used to date each indicator. We describe the composition of the global database, identify gaps in data availability, and highlight our effort to create an online platform to access the data. These data will be made available in a special issue of Quaternary Science Reviews and archived on NOAA's National Centers for Environmental Information (NCEI) in early 2018. We also invite researchers who collect or model Holocene sea-level data to participate. Long-term, this effort will enhance predictions of 21st century sea-level rise, and provide a vital contribution to the assessment of natural hazards with respect to sea-level rise and coastal response.

  15. 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.

  16. Sea Level Rise and Consequences for Navigable Coastal Inlets

    DTIC Science & Technology

    2009-01-01

    Rosati, Ph.D., P.E., and Nicholas C. Kraus, Ph.D. U.S. Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory 3909 Halls Ferry...ac- company a rise in sea level. Means of planning for and coping with this process are also discussed. SEA LEVEL RISE Global or eustatic sea...Research and Development Center,Coastal and Hydraulics Laboratory,3909 Halls Ferry Rd,Vicksburg,MS,39180 8. PERFORMING ORGANIZATION REPORT NUMBER 9

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. The Paris Agreement's imprint on 2300 sea level rise

    NASA Astrophysics Data System (ADS)

    Mengel, Matthias; Nauels, Alexander; Rogelj, Joeri; Schleussner, Carl-Friedrich

    2017-04-01

    The 2015 Paris Agreement aims at reducing climate-related risks by putting a limit to global mean temperature increase. Furthermore, global greenhouse gas emissions should peak as soon as possible and reach net-zero in the second half of the 21st century under the agreement. Sea level rise is one of the major impacts of climate change and will continue for long after emissions have ceased. Here we quantify the effect of near-term and long-term emissions constraints of the Paris Agreement on climate-driven sea level rise until 2300 using a contribution-based methodology that is consistent with the IPCC AR5 sea level estimates. We study median sea level rise for scenarios stabilizing global mean temperatures between 1.5° C and 2° C above pre-industrial levels and net-zero greenhouse gas emission scenarios that lead to declining temperatures. Once global mean temperatures pass 1.5 °C, sea level rise below one meter until 2300 is out of reach for temperature stabilization scenarios. Net-zero emissions can reduce sea level rise caused by temperature overshoot only within limits. By linking sea level rise to near-term mitigation action, we find that delayed near-term mitigation action leads to increased sea level rise far beyond 2100.

  2. Muon Muon Collider: Feasibility Study

    SciTech Connect

    Gallardo, J.C.; Palmer, R.B.; Tollestrup, A.V.; Sessler, A.M.; Skrinsky, A.N.; Ankenbrandt, C.; Geer, S.; Griffin, J.; Johnstone, C.; Lebrun, P.; McInturff, A.; Mills, Frederick E.; Mokhov, N.; Moretti, A.; Neuffer, D.; Ng, K.Y.; Noble, R.; Novitski, I.; Popovic, M.; Qian, C.; Van Ginneken, A. /Fermilab /Brookhaven /Wisconsin U., Madison /Tel Aviv U. /Indiana U. /UCLA /LBL, Berkeley /SLAC /Argonne /Sobolev IM, Novosibirsk /UC, Davis /Munich, Tech. U. /Virginia U. /KEK, Tsukuba /DESY /Novosibirsk, IYF /Jefferson Lab /Mississippi U. /SUNY, Stony Brook /MIT /Columbia U. /Fairfield U. /UC, Berkeley

    2012-04-05

    A feasibility study is presented of a 2 + 2 TeV muon collider with a luminosity of L = 10{sup 35} cm{sup -2}s{sup -1}. The resulting design is not optimized for performance, and certainly not for cost; however, it does suffice - we believe - to allow us to make a credible case, that a muon collider is a serious possibility for particle physics and, therefore, worthy of R and D support so that the reality of, and interest in, a muon collider can be better assayed. The goal of this support would be to completely assess the physics potential and to evaluate the cost and development of the necessary technology. The muon collider complex consists of components which first produce copious pions, then capture the pions and the resulting muons from their decay; this is followed by an ionization cooling channel to reduce the longitudinal and transverse emittance of the muon beam. The next stage is to accelerate the muons and, finally, inject them into a collider ring wich has a small beta function at the colliding point. This is the first attempt at a point design and it will require further study and optimization. Experimental work will be needed to verify the validity of diverse crucial elements in the design. Muons because of their large mass compared to an electron, do not produce significant synchrotron radiation. As a result there is negligible beamstrahlung and high energy collisions are not limited by this phenomena. In addition, muons can be accelerated in circular devices which will be considerably smaller than two full-energy linacs as required in an e{sup +} - e{sup -} collider. A hadron collider would require a CM energy 5 to 10 times higher than 4 TeV to have an equivalent energy reach. Since the accelerator size is limited by the strength of bending magnets, the hadron collider for the same physics reach would have to be much larger than the muon collider. In addition, muon collisions should be cleaner than hadron collisions. There are many detailed particle

  3. Regional Long-Term Sea Level and Sea Surface Temperature Characteristics from Satellite Observations

    NASA Astrophysics Data System (ADS)

    Andersen, O. B.; Knudsen, P.; Beckley, B.

    2006-07-01

    For a the large portion of the world's population liv ing in coastal zones forecasts of long- term sea lev el change is importan t for a var iety of environmen tal and socio- economic r easons. Satellite altimetry offers a unique opportunity for improving our knowledge about glob al and r egional sea level change on bo th global and reg ional scale. Joint TOPEX/PO SEIDON(T/P) +JASON-1 sea level observations and Reyno lds AVH RR sea surface temperature observ ations over th e most recen t 12 years hav e qualitativ ely been used to study regional correlations between long-term changes in sea level and sea surface temper ature. Long-term is here tak en to be lin ear signals in the 12-year time per iod Consistent in creases in both sea level and sea surface temp eratures ar e found in large parts of the world's oceans over this per iod. In the Indian Ocean and particularly th e Pacif ic Ocean , the trends in both sea level and temper ature are domin ated by the larg e changes associated w ith th e El N iño Southern Oscillation (ENSO) . Co mparison with similar trend estimates u sing only 8 years of satellite data shows the incr eased decoupling with ENSO and th e imp act of inter-annual variability on sea lev el tr end estimates.

  4. Developing advanced tools for modelling extreme sea level climate change in European Seas

    NASA Astrophysics Data System (ADS)

    She, Jun; Murawski, Jens; Hintz, Kasper S.

    2017-04-01

    With increasing speed of global warming, sea level rise in the European coasts has become increasing threats to our social-economy and safety. "Hundred-year storm surge events" have been reported in different locations in recent years. Ocean hydrodynamic modelling is one of the major tools for reconstructing and predicting sea level changes in climate scales. Although storm surge modelling is one of the most classic applications of ocean models, there still exist changes in producing accurate sea level variability in all European Sea coasts, especially for the extreme events. This presentation addresses major challenges in pan-European storm surge modelling, presenting sea level simulation results from a two-way nested pan-European Sea (with 10 sub-domains) three-dimensional hydrodynamic model HIROMB-BOOS (HBM). The difference of using two-dimensional and three-dimensional models for storm surge prediction is also analyzed based on past years' operational experiences.

  5. 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.

  6. 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.

  7. Upper limit for sea level projections by 2100

    NASA Astrophysics Data System (ADS)

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

    2014-10-01

    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. This leads to an intrinsically hard to quantify fat tail in the probability distribution for global mean sea level rise. Thus our low probability upper limit of sea level projections cannot be considered definitive. Nevertheless, our upper limit of 180 cm for sea level rise by 2100 is based on both expert opinion and process studies and hence indicates that other lines of evidence are needed to justify a larger sea level rise this century.

  8. Sea-level-rise impacts: Questioning inevitable migration

    NASA Astrophysics Data System (ADS)

    Kniveton, Dominic

    2017-08-01

    It is assumed that sea-level rise due to climate change will be so severe that those living near sea level will be forced to relocate. However, new research around a series of islands that have suffered subsidence due to a recent earthquake suggests that instead, island residents remain and use a range of strategies to adapt to regular flooding.

  9. Separating decadal global water cycle variability from sea level rise.

    PubMed

    Hamlington, B D; Reager, J T; Lo, M-H; Karnauskas, K B; Leben, R R

    2017-04-20

    Under a warming climate, amplification of the water cycle and changes in precipitation patterns over land are expected to occur, subsequently impacting the terrestrial water balance. On global scales, such changes in terrestrial water storage (TWS) will be reflected in the water contained in the ocean and can manifest as global sea level variations. Naturally occurring climate-driven TWS variability can temporarily obscure the long-term trend in sea level rise, in addition to modulating the impacts of sea level rise through natural periodic undulation in regional and global sea level. The internal variability of the global water cycle, therefore, confounds both the detection and attribution of sea level rise. Here, we use a suite of observations to quantify and map the contribution of TWS variability to sea level variability on decadal timescales. In particular, we find that decadal sea level variability centered in the Pacific Ocean is closely tied to low frequency variability of TWS in key areas across the globe. The unambiguous identification and clean separation of this component of variability is the missing step in uncovering the anthropogenic trend in sea level and understanding the potential for low-frequency modulation of future TWS impacts including flooding and drought.

  10. 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…

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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…

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. Understanding Sea Level Change: A Physics Based Approach

    NASA Astrophysics Data System (ADS)

    Kim, K. Y.

    2014-12-01

    Sea level change is an issue of immense importance in conjunction with global warming. The advent of satellite measurements offers a unique opportunity to address the global patterns of sea level height change associated with global warming. The rate of sea level change, however, is still uncertain due to the relatively short length of the satellite measurements, which began in 1993. In the present study, the contribution of global warming was separated from natural variability via cyclostationary EOF analysis in a sea level reconstruction dataset covering 1950-2010. Global sea level change due to the warming signal is within the range of fluctuations of the global average sea level computed directly from the data but is much less contaminated by natural variability as in the globally averaged sea level heights. A quadratic polynomial fit to the global warming signal indicates that the rate of sea level rise has increased by 0.2 mm yr-1 per decade and is 1.3 mm yr-1 as of 2010. The current rate of sea level rise is lower than that estimated from the globally averaged sea level heights by 0.2 mm yr-1 but is in the 1s range of the estimate (1.3 - 1.8 mm yr-1). Separation of the global warming mode from natural variability allow us to estimate the magnitude of natural variability and the relative significance of sea level change due to global warming. It appears that the sea level change due to global warming is, in general, comparable to natural variability in magnitude so far. Notable exceptions are over the southern tropical Indian, equatorial Pacific, tropical Atlantic, and along the extensions of the western boundary currents. Sea level rise due to warming is expected to exceed several standard deviations of natural variability by 2060 over the majority of the world oceans. This implies that coastal regions will be much more prone to disasters (such as hurricanes) due to warming-induced sea level rise.

  2. 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.

  3. 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.

  4. Greenhouse effect, sea level rise, and coastal zone management

    SciTech Connect

    Titus, J.G.

    1986-01-01

    Increasing concentrations of carbon dioxide and other gases are expected to warm the earth several degrees in the next century by a mechanism known as the greenhouse effect. Such a warming could cause sea level to rise two to five feet by expanding ocean water, melting mountain glaciers, and perhaps eventually causing polar glaciers to melt and slide into the oceans. A rise in sea level of even three feet could cause substantial erosion of beaches and coastal wetlands, increased flooding, and intrusion of salt water into rivers, bays, and aquifer. Fortunately, many of the adverse consequences can be avoided by taking timely measures in anticipation of sea level rise. Nevertheless, many coastal zone managers are reluctant to take these measures until the prospect of sea level rise becomes more certain. This article examines the implications of future sea level rise and identifies anticipatory measures that may be appropriate today in spite of current uncertainties. 46 references, 4 figures, 1 table.

  5. 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.

  6. 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.

  7. Lifetime of Cosmic-Ray Muons and the Standard Model of Fundamental Particles

    NASA Astrophysics Data System (ADS)

    Mukherji, Sahansha; Shevde, Yash; Majewski, Walerian

    2015-04-01

    Muon is one of the twelve fundamental particles of matter, having the longest free-particle lifetime. It decays into three other leptons through an exchange of the weak vector bosons W+/W-. Muons are present in the secondary cosmic ray showers in the atmosphere, reaching the sea level. By detecting time delay between arrival of the muon and an appearance of the decay electron in our single scintillation detector (donated by the Thomas Jefferson National Accelerator Facility, Newport News, VA), we measured muon's lifetime at rest. It compares well with the value predicted by the Standard Model of Particles. From the lifetime we were able to calculate the ratio gw /MW of the weak coupling constant gw (an analog of the electric charge) to the mass of the W-boson MW. Using further Standard Model relations and an experimental value for MW, we calculated the weak coupling constant, the electric charge of the muon, and the vacuum expectation value of the Higgs field. We determined the sea-level flux of cosmic muons.

  8. 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.

  9. High-energy cosmic ray muons in the Earth's atmosphere

    SciTech Connect

    Kochanov, A. A.; Sinegovskaya, T. S.; Sinegovsky, S. I.

    2013-03-15

    We present the calculations of the atmospheric muon fluxes at energies 10-10{sup 7} GeV based on a numerical-analytical method for solving the hadron-nucleus cascade equations. It allows the non-power-law behavior of the primary cosmic ray (PCR) spectrum, the violation of Feynman scaling, and the growth of the total inelastic cross sections for hadron-nucleus collisions with increasing energy to be taken into account. The calculations have been performed for a wide class of hadron-nucleus interaction models using directly the PCR measurements made in the ATIC-2 and GAMMA experiments and the parameterizations of the primary spectrum based on a set of experiments. We study the dependence of atmospheric muon flux characteristics on the hadronic interaction model and the influence of uncertainties in the PCR spectrum and composition on the muon flux at sea level. Comparison of the calculated muon energy spectra at sea level with the data from a large number of experiments shows that the cross sections for hadron-nucleus interactions introduce the greatest uncertainty in the energy region that does not include the knee in the primary spectrum.

  10. Sea level rise and variability around Peninsular Malaysia

    NASA Astrophysics Data System (ADS)

    Tkalich, Pavel; Luu, Quang-Hung; Tay, Tze-Wei

    2014-05-01

    Peninsular Malaysia is bounded from the west by Malacca Strait and the Andaman Sea, both connected to the Indian Ocean, and from the east by South China Sea being largest marginal sea in the Pacific Basin. As a result, sea level along Peninsular Malaysia coast is assumed to be governed by various regional phenomena associated with the adjacent parts of the Indian and Pacific Oceans. At annual scale, sea level anomalies (SLAs) are generated by the Asian monsoon; interannual sea level variability is determined by the El Niño-Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD); whilst long term sea level trend is coordinated by the global climate change. To quantify the relative impacts of these multi-scale phenomena on sea level trend and variability surrounding the Peninsular Malaysia, long-term tide gauge record and satellite altimetry are used. During 1984-2011, relative sea level rise (SLR) rates in waters of Malacca Strait and eastern Peninsular Malaysia are found to be 2.4 ± 0.8 mm/yr and 2.7 ± 0.6 mm/yr, respectively. Discounting for their vertical land movements (0.8 ± 2.6 mm/yr and 0.9 ± 2.2 mm/yr, respectively), their pure SLR rates are 1.6 ± 3.4 mm/yr and 1.8 ± 2.8 mm/yr, respectively, which are lower than the global tendency. At interannual scale, ENSO affects sea level over the Malaysian east coast in the range of ± 5 cm with very high correlation coefficient. Meanwhile, IOD modulates sea level anomalies in the Malacca Strait in the range of ± 2 cm with high correlation coefficient. Interannual regional sea level drops are associated with El Niño events and positive phases of the IOD index; while the rises are correlated with La Niña episodes and the negative periods of the IOD index. Seasonally, SLAs are mainly monsoon-driven, in the order of 10-25 cm. Geographically, sea level responds differently to the monsoon: two cycles per year are observed in the Malacca Strait, presumably due to South Asian - Indian Monsoon; while single

  11. 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.

  12. 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.

  13. 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

  14. Uncovering the Anthropogenic Sea Level Change using an Improved Sea Level Reconstruction for the Indian Ocean

    NASA Astrophysics Data System (ADS)

    Kumar, P.; Hamlington, B.; Thompson, P. R.; Han, W.

    2016-12-01

    Despite having some of the world's most densely populated and vulnerable coastal regions, sea level (SL) variability in the Indian Ocean (IO) has received considerably less attention than the Pacific Ocean. Differentiating the internal variability from the long-term trend in global mean sea level (GMSL) at decadal time-scales is vital for planning and mitigation efforts in the IO region. Understanding the dynamics of internal and anthropogenic SL change is essential for understanding the dynamic pathways that link the IO basin to terrestrial climates world-wide. With a sparse pre-satellite observational record of the IO, the Indo-Pacific internal climate variability is difficult to represent accurately. However, an improved representation of pre-satellite SL variability can be achieved by using a multivariate reconstruction technique. By using cyclostationary empirical orthogonal functions (CSEOFs) that can capture time-varying spatial patterns, gaps in the historical record when observations are sparse are filled using spatial relationships from time periods when the observational network is dense. This reconstruction method combines SL data and sea surface temperature (SST) to create a SL reconstruction that spans a period from 1900 to present, long enough to study climate signals over interannual to decadal time scales. This study aims at estimating the component of SL rise that relates to anthropogenic forcing by identifying and removing the fraction related to internal variability. An improved understanding of how the internal climate variability can affect the IO SL trend and variability, will provide an insight into the future SL changes. It is also important to study links between SL and climate variability in the past to understand how SL will respond to similar climatic events in the future and if this response will be influenced by the changing climate.

  15. Climate variabilities of sea level around the Korean Peninsula

    NASA Astrophysics Data System (ADS)

    Youn, Yong-Hoon; Oh, Im Sang; Park, Young-Hyang; Kim, Ki-Hyun

    2004-08-01

    In order to study the climate variabilities of the sea level around the Korean Peninsula, tidal data observed at local stations in Korea were compared against those obtained using TOPEX/POSEIDON (T/P) altimetric sea level data. In the course of our study, the amount of sea level rise was estimated using the tidal data from 9 stations selected by an anomaly coherency analysis. The results indicated that the sea level has risen by 0.28 cm yr-1 around the Korean Peninsula over the past two decades. The extent of such a rise is about two times higher than that of the global increase (0.1 0.2 cm yr-1). However, because most global warming effects occurred mainly over mid- and high-latitudes, this level of change appears to be realistic. According to the spectral analysis (at a spectral window of k = 2, k is the number of subdivisions), the decadal band of sea level variability is computed at 30% of the energy. Its spectral peak is found at 12.8 years. In the interannual band, the predominant sea level variability is in the 1.4 1.9-year band, with a sharp peak at 1.6 years. A secondary peak, although marginal, has a period of 2.2 years. Based on our estimates of sea level height from Topex/Poseidon, the quasi-biennial periodicity of 1.6 years is the representative interannual sea level variability in the seas adjacent to Korea. Trends vary greatly according to the geographical location, from a maximum of 1.0 cm yr-1 (the southern sector of the East Sea) to a minimum of 0.17 cm yr-1 (the northern sector of the East Sea). This is fairly consistent with the qualitative description already given with reference to the global map. As an analogue to the pattern seen in Korea, that of the Yellow Sea reveals practically the same trend as that of the adjacent seas (0.56 cm yr-1). However, in the case of TOPEX/POSEIDON (T/P) data, there is no clear evidence of a linkage between the interannual sea level variability around the Korean Peninsula and ENSO.

  16. 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

  17. 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.

  18. 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.

  19. Decadal sea level variability in the East China Sea linked to the North Pacific Gyre Oscillation

    NASA Astrophysics Data System (ADS)

    Moon, Jae-Hong; Song, Y. Tony

    2017-07-01

    In view of coastal community's need for adapting to sea level rise (SLR), understanding and predicting regional variability on decadal to longer time scales still remain a challenging issue in SLR research. Here, we have examined the low-frequency sea level signals in the East China Sea (ECS) from the 50-year hindcast of a non-Boussinesq ocean model in comparison with data sets from altimeters, tide-gauges, and steric sea level produced by in-situ profiles. It is shown that the mean sea levels in the ECS represent significant decadal fluctuations over the past 50 years, with a multi-decadal trend shift since the mid-1980s compared to the preceding 30 years. The decadal fluctuations in sea level are more closely linked to the North Pacific Gyre Oscillation (NPGO) rather than the Pacific Decadal Oscillation, which reflects the multi-decadal trend shift. A composite analysis indicates that wind patterns associated with the NPGO is shown to control the decadal variability of the western subtropical North Pacific. A positive NPGO corresponds to cyclonic wind stress curl anomaly in the western subtropical regions that results in a higher sea level in the ECS, particularly along the continental shelf, and lower sea levels off the ECS. The reverse occurs in years of negative NPGO.

  20. 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.

  1. Improving sea level simulation in Mediterranean regional climate models

    NASA Astrophysics Data System (ADS)

    Adloff, Fanny; Jordà, Gabriel; Somot, Samuel; Sevault, Florence; Arsouze, Thomas; Meyssignac, Benoit; Li, Laurent; Planton, Serge

    2017-08-01

    For now, the question about future sea level change in the Mediterranean remains a challenge. Previous climate modelling attempts to estimate future sea level change in the Mediterranean did not meet a consensus. The low resolution of CMIP-type models prevents an accurate representation of important small scales processes acting over the Mediterranean region. For this reason among others, the use of high resolution regional ocean modelling has been recommended in literature to address the question of ongoing and future Mediterranean sea level change in response to climate change or greenhouse gases emissions. Also, it has been shown that east Atlantic sea level variability is the dominant driver of the Mediterranean variability at interannual and interdecadal scales. However, up to now, long-term regional simulations of the Mediterranean Sea do not integrate the full sea level information from the Atlantic, which is a substantial shortcoming when analysing Mediterranean sea level response. In the present study we analyse different approaches followed by state-of-the-art regional climate models to simulate Mediterranean sea level variability. Additionally we present a new simulation which incorporates improved information of Atlantic sea level forcing at the lateral boundary. We evaluate the skills of the different simulations in the frame of long-term hindcast simulations spanning from 1980 to 2012 analysing sea level variability from seasonal to multidecadal scales. Results from the new simulation show a substantial improvement in the modelled Mediterranean sea level signal. This confirms that Mediterranean mean sea level is strongly influenced by the Atlantic conditions, and thus suggests that the quality of the information in the lateral boundary conditions (LBCs) is crucial for the good modelling of Mediterranean sea level. We also found that the regional differences inside the basin, that are induced by circulation changes, are model-dependent and thus not

  2. Mapping the Causes and Impacts of Decadal Sea Level Variability

    NASA Astrophysics Data System (ADS)

    Hamlington, B.

    2016-12-01

    Under a warming climate, increased variability in the water cycle and changes in precipitation patterns over land are expected to occur, subsequently impacting the terrestrial water cycle/balance. On global scales, such changes in terrestrial water storage (TWS) will be reflected in the water contained in the ocean and manifest as sea level variations. Thus, naturally occurring climate-driven water storage variability can potentially serve to obscure the long-term trend in sea level rise, in addition to modulating the impacts of sea level rise through natural periodic undulation in regional and global sea level. Here, we use a broad suite of observations, focusing on those from satellites in particular, to examine the link between sea level variability and TWS on decadal timescales. We find that decadal sea level variability centered in the Pacific Ocean is closely tied to the occurrence of extended periods of increased and decreased TWS in many areas across the globe. Identifying this variability has important implications for uncovering the background trend in sea level, and we examine how separating decadal variability from the satellite altimetry record impacts the ability the estimate an acceleration from the relatively short satellite record. The results here also demonstrate that precipitation-driven variability that is regional in nature can lead to decadal changes in the exchange of water between land and ocean that is measurable on global scales. While on a basic level the resulting relationship between global mean sea level, precipitation and TWS is not unexpected, extracting a signal from multiple climate variables that persists for a decade and undergoes regular shifts in phase as evidenced by the historical record establishes an important link between sea level, TWS, and precipitation that can be tracked and monitored in the future.

  3. Sea level rise with warming above 2 degree

    NASA Astrophysics Data System (ADS)

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

    2017-04-01

    Holding the increase in the global average temperature to below 2 °C above pre-industrial levels, and pursuing efforts to limit the temperature increase to 1.5 °C, has been agreed by the representatives of the 196 parties of United Nations, as an appropriate threshold beyond which climate change risks become unacceptably high. Sea level rise is one of the most damaging aspects of warming climate for the more than 600 million people living in low-elevation coastal areas less than 10 meters above sea level. Fragile coastal ecosystems and increasing concentrations of population and economic activity in coastal areas, are reasons why future sea level rise is one of the most damaging aspects of the warming climate. Furthermore, sea level is set to continue to rise for centuries after greenhouse gas emissions concentrations are stabilised due to system inertia and feedback time scales. Impact, risk, adaptation policies and long-term decision making in coastal areas depend on regional and local sea level rise projections and local projections can differ substantially from the global one. Here we provide probabilistic sea level rise projections for the global coastline with warming above the 2 degree goal. A warming of 2°C makes global ocean rise on average by 20 cm, but more than 90% of coastal areas will experience greater rises, 40 cm along the Atlantic coast of North America and Norway, due to ocean dynamics. If warming continues above 2°C, then by 2100 sea level will rise with speeds unprecedented throughout human civilization, reaching 0.9 m (median), and 80% of the global coastline will exceed the global ocean sea level rise upper 95% confidence limit of 1.8 m. Coastal communities of rapidly expanding cities in the developing world, small island states, and vulnerable tropical coastal ecosystems will have a very limited time after mid-century to adapt to sea level rises.

  4. Past sea level reconstruction and variability of sea level trend patterns over 1970-2001 in the Mediterranean Sea basin derived from Altimetry and 2 long OGCM runs.

    NASA Astrophysics Data System (ADS)

    Meyssignac, Benoit; Cazenave, Anny; Morrow, Rosemary; Marcos, Marta; Calafat, Francisco; Llovel, William

    2010-05-01

    For the past decades, there are no direct basin-scale sea level observations concerning the spatial sea level patterns and their evolution in the Mediterranean Sea. In order to understand physical processes driving sea level variability it is important to know the dominant modes of regional variability on interannual/decadal/multidecadal time scale in the Mediterranean basin. It is also of interest for assessing ocean circulation models dedicated to the Mediterranean Sea. For these purposes, we have developed a reconstruction method of past Mediterranean sea level (since 1970) that combines long tide gauge records of limited spatial coverage and 2-D sea level patterns based on the AVISO altimetry dataset and on runs from two different Ocean General Circulation Models (OGCMs). In the latter case, we use runs from the ORCA05 model (without data assimilation) over 1958-2005 available from the DRAKKAR project and the SODA reanalysis over 1958-2005 available from GODAE (Carton et al., 2008), assimilating all available in situ temperature, salinity and sea level data. We also perform the past sea level reconstruction over the Mediterranean Sea using 2-D spatial patterns from satellite altimetry. The three sea level reconstructions are inter-compared, together with results from a published study (Calafat and Gomis, 2009). The dominant modes of temporal variability are discussed and sea level hindcasts at tide gauge sites not used in the analysis are compared to actual observations. Comparisons with steric sea level patterns based on in situ hydrographic data are also presented and discussed with regard to the conclusions of past studies based on tide gauge records analysis. .

  5. 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

  6. Lower bounds to future sea-level rise

    NASA Astrophysics Data System (ADS)

    Zecca, Antonio; Chiari, Luca

    2012-12-01

    Sea-level rise is among the most important changes expected as a consequence of anthropogenic global warming. Climate model-based projections made until the Fourth Assessment Report (AR4) of the Intergovernmental Panel on Climate Change (IPCC) yield a 21st century rise spanning nearly 20-60 cm. However, it is known that current climate models are likely to underestimate sea-level change in response to rapid climatic variations. Recent alternative semi-empirical approaches predict a much higher sea-level rise than the IPCC AR4 projections. Nevertheless, the underway depletion of conventional fossil fuels might, at least in principle, constrain future fossil CO2 emissions and, in turn, affect also the extent of sea-level rise. Here we project 2000-2200 sea-level rise with a semi-empirical method coupled to a simple climate model that is run under a range of fossil-fuel exhaustion scenarios. We find that, in spite of fossil-fuel depletion, sea level is predicted to rise by at least ~ 80 cm at the end of this century and is expected to continue rising for at least the next two hundred years. The present results support the need for prompt and substantial emission cuts in order to slow down future sea-level rise and implement adaptation measures.

  7. 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.

  8. 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).

  9. 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.

  10. 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.

  11. 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.

  12. Polarized muon beams for muon collider

    NASA Astrophysics Data System (ADS)

    Skrinsky, A. N.

    1996-11-01

    An option for the production of intense and highly polarized muon beams, suitable for a high-luminosity muon collider, is described briefly. It is based on a multi-channel pion-collection system, narrow-band pion-to-muon decay channels, proper muon spin gymnastics, and ionization cooling to combine all of the muon beams into a single bunch of ultimately low emittance.

  13. Analysis of Sea Level Rise in Singapore Strait

    NASA Astrophysics Data System (ADS)

    Tkalich, Pavel; Luu, Quang-Hung

    2013-04-01

    Sea level in Singapore Strait is governed by various scale phenomena, from global to local. Global signals are dominated by the climate change and multi-decadal variability and associated sea level rise; at regional scale seasonal sea level variability is caused by ENSO-modulated monsoons; locally, astronomic tides are the strongest force. Tide gauge records in Singapore Strait are analyzed to derive local sea level trend, and attempts are made to attribute observed sea level variability to phenomena at various scales, from global to local. It is found that at annual scale, sea level anomalies in Singapore Strait are quasi-periodic, of the order of ±15 cm, the highest during northeast monsoon and the lowest during southwest monsoon. Interannual regional sea level falls are associated with El Niño events, while the rises are related to La Niña episodes; both variations are in the range of ±9 cm. At multi-decadal scale, sea level in Singapore Strait has been rising at the rate 1.2-1.9 mm/year for the period 1975-2009, 2.0±0.3 mm/year for 1984-2009, and 1.3-4.7 mm/year for 1993-2009. When compared with the respective global trends of 2.0±0.3, 2.4, and 2.8±0.8 mm/year, Singapore Strait sea level rise trend was weaker at the earlier period and stronger at the recent decade.

  14. 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.

  15. 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

  16. 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

  17. 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

  18. 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.

  19. 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.

  20. 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).

  1. Sea level trend and variability around Peninsular Malaysia

    NASA Astrophysics Data System (ADS)

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

    2015-08-01

    Sea level rise due to climate change is non-uniform globally, necessitating regional estimates. Peninsular Malaysia is located in the middle of Southeast Asia, bounded from the west by the Malacca Strait, from the east by the South China Sea (SCS), and from the south by the Singapore Strait. The sea level along the peninsula may be influenced by various regional phenomena native to the adjacent parts of the Indian and Pacific oceans. To examine the variability and trend of sea level around the peninsula, tide gauge records and satellite altimetry are analyzed taking into account vertical land movements (VLMs). At annual scale, sea level anomalies (SLAs) around Peninsular Malaysia on the order of 5-25 cm are mainly monsoon driven. Sea levels at eastern and western coasts respond differently to the Asian monsoon: two peaks per year in the Malacca Strait due to South Asian-Indian monsoon; an annual cycle in the remaining region mostly due to the East Asian-western Pacific monsoon. At interannual scale, regional sea level variability in the range of ±6 cm is correlated with El Nino-Southern Oscillation (ENSO). SLAs in the Malacca Strait side are further correlated with the Indian Ocean Dipole (IOD) in the range of ±5 cm. Interannual regional sea level falls are associated with El Nino events and positive phases of IOD, whilst rises are correlated with La Nina episodes and negative values of the IOD index. At seasonal to interannual scales, we observe the separation of the sea level patterns in the Singapore Strait, between the Raffles Lighthouse and Tanjong Pagar tide stations, likely caused by a dynamic constriction in the narrowest part. During the observation period 1986-2013, average relative rates of sea level rise derived from tide gauges in Malacca Strait and along the east coast of the peninsula are 3.6±1.6 and 3.7±1.1 mm yr-1, respectively. Correcting for respective VLMs (0.8±2.6 and 0.9±2.2 mm yr-1), their corresponding geocentric sea level rise rates

  2. 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.

  3. 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

  4. Regional patterns of sea level change in the German North Sea in a worldwide context

    NASA Astrophysics Data System (ADS)

    Wahl, Thomas; Frank, Torsten; Jensen, Jürgen

    2010-05-01

    Sea Level Rise (SLR) is one of the major consequences we are facing in times of a warming climate and it is obvious that a higher sea level influences the heights of occurring storm surges and thus results in a higher risk of inundation for the affected coastal areas. Therefore, regional and global sea level rise are subjects to many recent scientific publications. In contrast, the mean sea level (MSL) and its variability over the last centuries in the German North Sea area have not been analysed in detail up to now. A methodology to analyse observed sea level rise (SLR) in the German Bight, the shallow south-eastern part of the North Sea, is presented. The contribution focuses on the description of the methods used to generate and analyse high quality mean sea level (MSL) time series. Parametric fitting approaches as well as non-parametric data adaptive filters, such as Singular System Analysis (SSA) are applied. For padding non-stationary sea level time series, an advanced approach named Monte-Carlo autoregressive padding (MCAP) is introduced. This approach allows the specification of uncertainties of the behaviour of smoothed time series near the boundaries. The results for the North Sea point to a weak negative acceleration of SLR since 1844 with a strong positive acceleration at the end of the 19th century, to a period of almost no SLR around the 1970s with subsequent positive acceleration and to high recent rates. The comparison between the German North Sea and a global sea level reconstruction clearly reveals the existence of different patterns of SLR. A stronger SLR in the German North Sea area is detected for a period covering some decades starting at the end of the 19th century and for another period covering the last ten to fifteen years. These findings and the indications for the natural variability of this complex system and further research topics will be discussed. This is a German Coastal Engineering Research Council (KFKI) project, funded by the

  5. 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

  6. Using Holocene relative sea-level data to inform future sea-level predictions: An example from southwest England

    NASA Astrophysics Data System (ADS)

    Gehrels, W. Roland; Dawson, David A.; Shaw, Jon; Marshall, William A.

    2011-08-01

    Holocene relative sea-level data contain information on vertical land movements along coasts and, hence, can provide vital input for predictions of future sea-level change. At Thurlestone, in southwest England, late Holocene coastal sediments were cored and sampled in coastal back-barrier marshes. The presence of a basal sedimentary unit containing salt-marsh microfossils made it possible to obtain precise estimates of late Holocene relative sea-level change from the sediments. This is important because previous studies have suggested that the southwest of England is experiencing the fastest rates of land subsidence in the British Isles. Ten new late Holocene basal sea-level index points fill an important gap in the palaeosea-level data set for southwest England. Another 15 early and middle Holocene sea-level index points are available from previous work. The data show that relative sea level rose by about 10 m between 9000 and 7000 cal. yr BP and a further 8 m in the last 7000 yr. In the last 2000 yr, relative sea level rose on average by 0.9 mm/yr. The coast is currently subsiding by 1.1 mm/yr due to ongoing glacial isostatic adjustment (GIA). The Bradley et al. (2009) GIA model, which is used in the United Kingdom to determine land-motion rates for input into future sea-level predictions, underestimates the rate of coastal subsidence by about 0.16 mm/yr, but performs better than other models. Our data validate the land-motion rates currently used in regional sea-level projections.

  7. 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.

  8. The multimillennial sea-level commitment of global warming

    PubMed Central

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

    2013-01-01

    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. PMID:23858443

  9. 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/2014AGUFMED13C3467T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMED13C3467T"><span>Climate And <span class="hlt">Sea</span> <span class="hlt">Level</span>: It's In Our Hands Now</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Turrin, M.; Bell, R. E.; Ryan, W. B. F.</p> <p>2014-12-01</p> <p>Changes in <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">Sea</span> <span class="hlt">Level</span> Rise Polar Explorer App developed through the PoLAR CCEP grant offers a guided tour through the many layers of science that impact <span class="hlt">sea</span> <span class="hlt">level</span> rise. This map-based data-rich app is framed around a series of questions that move the user through map layers with just the <span class="hlt">level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">level</span> 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 <span class="hlt">level</span> of the student group. The map layers also include a range of complexities. Basic questions like "What is <span class="hlt">sea</span> <span class="hlt">level</span>?" talk about shorelines, past <span class="hlt">sea</span> <span class="hlt">levels</span> and elevations beneath the <span class="hlt">sea</span>. Questions like "Why does <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span> change? Questions about "What about <span class="hlt">sea</span> <span class="hlt">level</span> in the past?" can bring challenges for students who have</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12553651','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12553651"><span>Measurements with a Ge detector and Monte Carlo computations of dose rate yields due to cosmic <span class="hlt">muons</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Clouvas, A; Xanthos, S; Antonopoulos-Domis, M; Silva, J</p> <p>2003-02-01</p> <p>The present work shows how portable Ge detectors can be useful for measurements of the dose rate due to ionizing cosmic radiation. The methodology proposed converts the cosmic radiation induced background in a Ge crystal (energy range above 3 MeV) to the absorbed dose rate due to <span class="hlt">muons</span>, which are responsible for 75% of the cosmic radiation dose rate at <span class="hlt">sea</span> <span class="hlt">level</span>. The key point is to observe in the high energy range (above 20 MeV) the broad <span class="hlt">muon</span> peak resulting from the most probable energy loss of <span class="hlt">muons</span> in the Ge detector. An energy shift of the <span class="hlt">muon</span> peak was observed, as expected, for increasing dimensions of three Ge crystals (10%, 20%, and 70% efficiency). Taking into account the dimensions of the three detectors the location of the three <span class="hlt">muon</span> peaks was reproduced by Monte Carlo computations using the GEANT code. The absorbed dose rate due to <span class="hlt">muons</span> has been measured in 50 indoor and outdoor locations at Thessaloniki, the second largest town of Greece, with a portable Ge detector and converted to the absorbed dose rate due to <span class="hlt">muons</span> in an ICRU sphere representing the human body by using a factor derived from Monte Carlo computations. The outdoor and indoor mean <span class="hlt">muon</span> dose rate was 25 nGy h(-1) and 17.8 nGy h(-1), respectively. The shielding factor for the 40 indoor measurements ranges from 0.5 to 0.9 with a most probable value between 0.7-0.8.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.5762L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.5762L"><span>Two Decades of Global and Regional <span class="hlt">Sea</span> <span class="hlt">Level</span> Observations from the ESA Climate Change Initiative <span class="hlt">Sea</span> <span class="hlt">Level</span> Project</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Legeais, JeanFrancois; Larnicol, Gilles; Cazenave, Anny; Ablain, Michael; Benveniste, Jérôme; Lucas, BrunoManuel; Timms, Gary; Johannessen, Johnny; Knudsen, Per; Cipollini, Paolo; Roca, Monica; Rudenko, Sergei; Fernandes, Joana; Balmaseda, Magdalena; Quartly, Graham; Fenoglio-Marc, Luciana; Scharfennberg, Martin; Meyssignac, Benoit; Guinle, Thierry; Andersen, Ole</p> <p>2015-04-01</p> <p><span class="hlt">Sea</span> <span class="hlt">level</span> is a very sensitive index of climate change and variability. <span class="hlt">Sea</span> <span class="hlt">level</span> integrates the ocean warming, mountain glaciers and ice sheet melting. Understanding the <span class="hlt">sea</span> <span class="hlt">level</span> variability and changes implies an accurate monitoring of the <span class="hlt">sea</span> <span class="hlt">level</span> variable at climate scales, in addition to understanding the ocean variability and the exchanges between ocean, land, cryosphere, and atmosphere. That is why <span class="hlt">Sea</span> <span class="hlt">Level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span> ECV with regular updates, as required for climate studies. After a first phase (2011-2013), the program has started in 2014 a second phase of 3 years. The objectives of this second phase are to involve the climate research community, to refine their needs and collect their feedbacks on product quality, to develop, test and select the best algorithms and standards to generate an updated climate time series and to produce and validate the <span class="hlt">Sea</span> <span class="hlt">Level</span> ECV product. This will better answer the climate user needs by improving the quality of the <span class="hlt">Sea</span> <span class="hlt">Level</span> products and maintain a sustain service for an up-to-date production. To this extent, the ECV time series has been extended and it now covers the period 1993-2013. We will firstly present the main achievements of the ESA CCI <span class="hlt">Sea</span> <span class="hlt">Level</span> Project. On the one hand, the major steps required to produce the 21 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, the work plan and key challenges of the second phase of the project are described.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.4218K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.4218K"><span><span class="hlt">Sea-level</span> variability over the Common Era</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kopp, Robert; Horton, Benjamin; Kemp, Andrew; Engelhart, Simon; Little, Chris</p> <p>2017-04-01</p> <p>The Common Era (CE) <span class="hlt">sea-level</span> response to climate forcing, and its relationship to centennial-timescale climate variability such as the Medieval Climate Anomaly (MCA) and the Little Ice Age (LIA), is fragmentary relative to other proxy-derived climate records (e.g. atmospheric surface temperature). However, the Atlantic coast of North America provides a rich sedimentary record of CE relative <span class="hlt">sea</span> <span class="hlt">level</span> with sufficient spatial and temporal resolution to inform mechanisms underlying regional and global <span class="hlt">sea</span> <span class="hlt">level</span> variability and their relationship to other climate proxies. This coast has a small tidal range, improving the precision of <span class="hlt">sea-level</span> reconstructions. Coastal subsidence (from glacial isostatic adjustment, GIA) creates accommodation space that is filled by salt-marsh peat and preserves accurate and precise <span class="hlt">sea-level</span> indicators and abundant material for radiocarbon dating. In addition to longer term GIA induced land-<span class="hlt">level</span> change from ongoing collapse of the Laurentide forebulge, these records are ideally situated to capture climate-driven <span class="hlt">sea</span> <span class="hlt">level</span> changes. The western North Atlantic Ocean <span class="hlt">sea</span> <span class="hlt">level</span> is sensitive to static equilibrium effects from melting of the Greenland Ice Sheet, as well as large-scale changes in ocean circulation and winds. Our reconstructions reveal two distinct patterns in <span class="hlt">sea-level</span> during the CE along the United States Atlantic coast: (1) South of Cape Hatteras, North Carolina, to Florida <span class="hlt">sea-level</span> rise is essentially flat, with the record dominated by long-term geological processes until the onset of historic rates of rise in the late 19th century; (2) North of Cape Hatteras to Connecticut, <span class="hlt">sea</span> <span class="hlt">level</span> rise to maximum around 1000CE, a <span class="hlt">sea-level</span> minimum around 1500 CE, and a long-term <span class="hlt">sea-level</span> rise through the second half of the second millennium. The northern-intensified <span class="hlt">sea-level</span> fall beginning 1000 is coincident with shifts toward persistent positive NAO-like atmospheric states inferred from other proxy records and is consistent with</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMED43A0678M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMED43A0678M"><span>Hazard Risk to Near <span class="hlt">Sea-Level</span> Populations due to Tropical Cyclone Intensification and <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>Montain, J.; Byrne, J. M.; Elsner, J.</p> <p>2010-12-01</p> <p>Tropical cyclone (TC) intensification has been well documented in the science literature. TC intensification combined with <span class="hlt">sea-level</span> rise contributes to an enhanced risk to huge populations living near <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">level</span> evaluation of the increasing risk to human life and health.</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/2016EGUGA..18.1563H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.1563H"><span>The importance of <span class="hlt">sea-level</span> research (Plinius Medal Lecture)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Horton, Benjamin</p> <p>2016-04-01</p> <p>200 million people worldwide live in coastal regions less than 5 meters above <span class="hlt">sea</span> <span class="hlt">level</span>. 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 <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea-level</span> rise and the frequency (recurrence interval) and magnitude of destructive events. Reconstructions of paleo <span class="hlt">sea</span> <span class="hlt">level</span> are important for identifying the meltwater contributions, constraining parameters in Earth-Ice models, and estimating past and present rates of spatially variable <span class="hlt">sea-level</span> change associated glacial isostatic adjustment, sediment compaction and tidal range variability. <span class="hlt">Sea-level</span> reconstructions capture multiple phases of climate and <span class="hlt">sea-level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span>. Geologic evidence of paleoearthquakes elucidates characteristic and repeated pattern of land-<span class="hlt">level</span> 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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6830903','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6830903"><span>Greenhouse effect, <span class="hlt">sea</span> <span class="hlt">level</span> rise, and coastal wetlands</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Titus, J.G.</p> <p>1988-07-01</p> <p>To further society's understanding of how to rationally respond to the possibility of a substantial rise in <span class="hlt">level</span>, EPA has undertaken assessments of the impacts of <span class="hlt">sea</span> <span class="hlt">level</span> rise on economic development, beach erosion control strategies, salinity of estuaries and aquifers, and coastal drainage and sewage systems. Those studies have generally found that even a one-foot rise in a <span class="hlt">sea</span> <span class="hlt">level</span> has important implications for the planning and design of coastal facilities. This report examines the potential impacts of <span class="hlt">sea</span> <span class="hlt">level</span> on coastal wetlands in the United States. Coastal marshes and swamps are generally within a few feet of <span class="hlt">sea</span> <span class="hlt">level</span>, and hence could be lost if seal <span class="hlt">level</span> rises significantly. Although new wetlands could form where new areas are flooded, this cannot happen where the land adjacent to today's wetlands is developed and protected from the rising <span class="hlt">sea</span>. Once built, neighborhoods can be expected to last a century or longer. Therefore, todays coastal development could limit the ability of coastal wetlands to survive <span class="hlt">sea</span> <span class="hlt">level</span> in the next century. Chapter 1 provides an overview of the greenhouse effect, projections of future <span class="hlt">sea</span> <span class="hlt">level</span> rise, the basis for expecting significant impacts on coastal wetlands, and possible responses. Chapters 2 and 3 present case studies of the potential impacts on wetlands around Charleston, South Carolina, and Long Beach Island, New Jersey, based on field surveys. Chapter 4 presents a first attempt to estimate the nationwide impact, based on topographic maps. Finally, Chapter 5 describes measures that wetland protection officials can take today. This report neither examines the impact of <span class="hlt">sea</span> <span class="hlt">level</span> rise on specific federal programs nor recommends specific policy changes.</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/2017GMD....10.2495N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017GMD....10.2495N"><span>Synthesizing long-term <span class="hlt">sea</span> <span class="hlt">level</span> rise projections - the MAGICC <span class="hlt">sea</span> <span class="hlt">level</span> model v2.0</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nauels, Alexander; Meinshausen, Malte; Mengel, Matthias; Lorbacher, Katja; Wigley, Tom M. L.</p> <p>2017-06-01</p> <p><span class="hlt">Sea</span> <span class="hlt">level</span> rise (SLR) is one of the major impacts of global warming; it will threaten coastal populations, infrastructure, and ecosystems around the globe in coming centuries. Well-constrained <span class="hlt">sea</span> <span class="hlt">level</span> projections are needed to estimate future losses from SLR and benefits of climate protection and adaptation. Process-based models that are designed to resolve the underlying physics of individual <span class="hlt">sea</span> <span class="hlt">level</span> drivers form the basis for state-of-the-art <span class="hlt">sea</span> <span class="hlt">level</span> projections. However, associated computational costs allow for only a small number of simulations based on selected scenarios that often vary for different <span class="hlt">sea</span> <span class="hlt">level</span> components. This approach does not sufficiently support <span class="hlt">sea</span> <span class="hlt">level</span> impact science and climate policy analysis, which require a <span class="hlt">sea</span> <span class="hlt">level</span> projection methodology that is flexible with regard to the climate scenario yet comprehensive and bound by the physical constraints provided by process-based models. To fill this gap, we present a <span class="hlt">sea</span> <span class="hlt">level</span> model that emulates global-mean long-term process-based model projections for all major <span class="hlt">sea</span> <span class="hlt">level</span> components. Thermal expansion estimates are calculated with the hemispheric upwelling-diffusion ocean component of the simple carbon-cycle climate model MAGICC, which has been updated and calibrated against CMIP5 ocean temperature profiles and thermal expansion data. Global glacier contributions are estimated based on a parameterization constrained by transient and equilibrium process-based projections. <span class="hlt">Sea</span> <span class="hlt">level</span> contribution estimates for Greenland and Antarctic ice sheets are derived from surface mass balance and solid ice discharge parameterizations reproducing current output from ice-sheet models. The land water storage component replicates recent hydrological modeling results. For 2100, we project 0.35 to 0.56 m (66 % range) total SLR based on the RCP2.6 scenario, 0.45 to 0.67 m for RCP4.5, 0.46 to 0.71 m for RCP6.0, and 0.65 to 0.97 m for RCP8.5. These projections lie within the range of the latest IPCC SLR</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.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/2016NatCC...6..253K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatCC...6..253K"><span>Overestimation of marsh vulnerability to <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>Kirwan, Matthew L.; Temmerman, Stijn; Skeehan, Emily E.; Guntenspergen, Glenn R.; Fagherazzi, Sergio</p> <p>2016-03-01</p> <p>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 <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span> rise, and that process-based models predict survival under a wide range of future <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span> rise, and the potential for marshes to migrate inland.</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('https://www.ncbi.nlm.nih.gov/pubmed/27346549','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27346549"><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="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Muis, Sanne; Verlaan, Martin; Winsemius, Hessel C; Aerts, Jeroen C J H; Ward, Philip J</p> <p>2016-06-27</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('http://adsabs.harvard.edu/abs/2010PhTea..48..328L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010PhTea..48..328L"><span>Does <span class="hlt">Sea</span> <span class="hlt">Level</span> Change When a Floating Iceberg Melts?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lan, Boon Leong</p> <p>2010-05-01</p> <p>On the answer page to a recent "Figuring Physics" question, the cute mouse asks another question: "Does the [<span class="hlt">sea</span>] water <span class="hlt">level</span> change if the iceberg melts?" The conventional answer2-4 is "no." However, in this paper I will show through a simple analysis involving Archimedes' principle that the <span class="hlt">sea</span> <span class="hlt">level</span> will rise. The analysis shows the wrong conventional answer is due to the wrong assumption that water from a melted iceberg has the same density as seawater. An iceberg is freshwater ice.5 The <span class="hlt">sea</span> <span class="hlt">level</span> rise is essentially due to the difference in the density of seawater (1024 kg/m3) and freshwater (1000 kg/m3). A simple experiment, suitable as an introductory laboratory exercise, that validates the predicted <span class="hlt">sea</span> <span class="hlt">level</span> rise is presented at the end of the paper.</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="https://images.nasa.gov/">NASA Image and Video Library</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://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('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://pubs.er.usgs.gov/publication/70169064','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70169064"><span>Overestimation of marsh vulnerability to <span class="hlt">sea</span> <span class="hlt">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>Kirwan, Matthew L.; Temmerman, Stijn; Skeehan, Emily E.; Guntenspergen, Glenn R.; Fagherazzi, Sergio</p> <p>2016-01-01</p> <p>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 <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span> rise, and that process-based models predict survival under a wide range of future <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span> rise, and the potential for marshes to migrate inland.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/15006428','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/15006428"><span><span class="hlt">MUON</span> ACCELERATION</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>BERG,S.J.</p> <p>2003-11-18</p> <p>One of the major motivations driving recent interest in FFAGs is their use for the cost-effective acceleration of <span class="hlt">muons</span>. This paper summarizes the progress in this area that was achieved leading up to and at the FFAG workshop at KEK from July 7-12, 2003. Much of the relevant background and references are also given here, to give a context to the progress we have made.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.5384G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.5384G"><span>North Atlantic <span class="hlt">sea-level</span> variability during the last millennium</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gehrels, Roland; Long, Antony; Saher, Margot; Barlow, Natasha; Blaauw, Maarten; Haigh, Ivan; Woodworth, Philip</p> <p>2014-05-01</p> <p>Climate modelling studies have demonstrated that spatial and temporal <span class="hlt">sea-level</span> variability observed in North Atlantic tide-gauge records is controlled by a complex array of processes, including ice-ocean mass exchange, freshwater forcing, steric changes, changes in wind fields, and variations in the speed of the Gulf Stream. Longer records of <span class="hlt">sea-level</span> change, also covering the pre-industrial period, are important as a 'natural' and long-term baseline against which to test model performance and to place recent and future <span class="hlt">sea-level</span> changes and ice-sheet change into a long-term context. Such records can only be reliably and continuously reconstructed from proxy methods. Salt marshes are capable of recording decimetre-scale <span class="hlt">sea-level</span> variations with high precision and accuracy. In this paper we present four new high-resolution proxy records of (sub-) decadal <span class="hlt">sea-level</span> variability reconstructed from salt-marsh sediments in Iceland, Nova Scotia, Maine and Connecticut that span the past 400 to 900 years. Our records, based on more than 100 new radiocarbon analyses, Pb-210 and Cs-137 measurements as well as other biological and geochemical age markers, together with hundreds of new microfossil observations from contemporary and fossil salt marshes, capture not only the rapid 20th century <span class="hlt">sea-level</span> rise, but also small-scale (decimetre, multi-decadal) <span class="hlt">sea-level</span> fluctuations during preceding centuries. We show that in Iceland three periods of rapid <span class="hlt">sea-level</span> rise are synchronous with the three largest positive shifts of the reconstructed North Atlantic Oscillation (NAO) index. Along the North American east coast we compare our data with salt-marsh records from New Jersey, North Carolina and Florida and observe a trend of increased pre-industrial <span class="hlt">sea-level</span> variability from south to north (Florida to Nova Scotia). Mass changes and freshwater forcing cannot explain this pattern. Based on comparisons with instrumental <span class="hlt">sea-level</span> data and modelling studies we hypothesise that</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/2017EGUGA..1917351G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1917351G"><span>Decadal <span class="hlt">sea-level</span> changes in the Indian Ocean</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gangan, Nidheesh; Vialard, Jerome; Lengaingne, Matthieu; Izumo, Takeshi; Alakkatt, Unnikrishnan</p> <p>2017-04-01</p> <p>While the Interdecadal Pacific Oscillation (IPO) has been identified as the main driver of natural decadal <span class="hlt">sea-level</span> variations in the Pacific, Indian Ocean natural decadal <span class="hlt">sea-level</span> variability remains a largely uncharted territory. In this study, we analyse Indian Ocean natural decadal <span class="hlt">sea-level</span> variations from a large set of observational products, CMIP3 and CMIP5 pre-industrial simulations. The various observational products display very consistent patterns of decadal <span class="hlt">sea-level</span> variability in the Pacific, but not in the Indian Ocean, most likely because of sparse observational coverage in the IO. In contrast, almost all CMIP simulations display two very consistent patterns of Indian Ocean decadal <span class="hlt">sea-level</span> variability, which explain a large part of the total <span class="hlt">sea-level</span> variance in this basin. The first mode consists of a dipolar <span class="hlt">sea-level</span> pattern, with negative signals in the eastern Indian Ocean from the west coast of Australia to the northern Bay of Bengal and positive signals northeast of Madagascar. This mode is largely driven by the wind variability related to the decadal variations of the Indian Ocean Dipole, which is partly independent from decadal climate variability in the tropical Pacific. The second mode is completely independent from decadal Pacific variability, and consists of a broad <span class="hlt">sea-level</span> pattern east of Madagascar. This mode is excited by decadal wind variations in the subtropical Indian Ocean, most likely associated with fluctuations of the Mascarene high. The two decadal modes identified in CMIP models are broadly consistent with those deduced from the relatively short altimeter dataset or from the longer ORA reanalysis. <span class="hlt">Sea-level</span> reconstructions generally reproduce the dipolar mode but do not capture the decadal <span class="hlt">sea-level</span> variability east of Madagascar, presumably because of the absence of long tide-gauge records in this region. This study hence illustrates that CMIP simulations can provide some guidance for identifying robust modes of</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://ntrs.nasa.gov/search.jsp?R=19870033250&hterms=sea+level+changes&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dsea%2Blevel%2Bchanges','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19870033250&hterms=sea+level+changes&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dsea%2Blevel%2Bchanges"><span>Accurate measurement of mean <span class="hlt">sea</span> <span class="hlt">level</span> changes by altimetric satellites</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Born, G. H.; Tapley, B. D.; Ries, J. C.; Stewart, R. H.</p> <p>1986-01-01</p> <p>A technique for monitoring changes in global mean <span class="hlt">sea</span> <span class="hlt">levels</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span> are investigated. The data reveal that the stability of an altimeter can be determined with an accuracy of + or - 7 cm using globally averaged <span class="hlt">sea</span> surface height measurements. The application of this procedure to the US/French Ocean Topography Experiment is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920037309&hterms=sea+level&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dsea%2Blevel','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920037309&hterms=sea+level&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dsea%2Blevel"><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://ntrs.nasa.gov/search.jsp?R=19870033250&hterms=sea+level+change&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dsea%2Blevel%2Bchange','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19870033250&hterms=sea+level+change&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dsea%2Blevel%2Bchange"><span>Accurate measurement of mean <span class="hlt">sea</span> <span class="hlt">level</span> changes by altimetric satellites</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Born, G. H.; Tapley, B. D.; Ries, J. C.; Stewart, R. H.</p> <p>1986-01-01</p> <p>A technique for monitoring changes in global mean <span class="hlt">sea</span> <span class="hlt">levels</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span> are investigated. The data reveal that the stability of an altimeter can be determined with an accuracy of + or - 7 cm using globally averaged <span class="hlt">sea</span> surface height measurements. The application of this procedure to the US/French Ocean Topography Experiment is discussed.</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('http://adsabs.harvard.edu/abs/2017EGUGA..19.7162B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.7162B"><span>A Holocene <span class="hlt">sea-level</span> database for Southeast Asia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bender, Maren; Mann, Thomas; Stocchi, Paolo; Switzer, Adam; Horton, Benjamin P.; Lukman, Muhammad; Jompa, Jamaluddin; Rovere, Alessio</p> <p>2017-04-01</p> <p>The study of former relative <span class="hlt">sea-level</span> (RSL) changes is essential to disentangle changes in <span class="hlt">sea</span> <span class="hlt">level</span> due to vertical land motion (e.g. tectonics, Glacial Isostatic Adjustment - GIA) and eustatic (e.g. ice equivalent <span class="hlt">sea</span> <span class="hlt">level</span>) causes. To study RSL changes at a regional scale it is essential that databases of <span class="hlt">sea-level</span> indicators are produced following standardized protocols (Hijma et al., 2015). This has been already done in several regions (e.g. the US Atlantic coast, the Caribbean, or the Mediterranean (Engelhart and Horton, 2012) A database has been compiled for Southeast Asia but was limited in geographical extent and didn't include the influence of local process such as tidal range changes and compaction. Southeast Asia is highly vulnerable to relative <span class="hlt">sea</span> <span class="hlt">level</span> changes, as it is characterized by low-lying, densely populated islands and subsiding deltas. We present a database of Holocene <span class="hlt">sea-level</span> histories in Southeast Asia and part of the Indo-Pacific from published and unpublished data, which has been evaluated and using a standardized protocol. We analyzed 526 <span class="hlt">sea</span> <span class="hlt">level</span> index points, defining their locations the height of former <span class="hlt">sea</span> <span class="hlt">level</span> and the age with their associated uncertainty. Radiocarbon ages were re-calibrated using Calib 7.0.0 / 7.1 (Stuiver et al., 2017) and the calibration curves Intcal13 or Marine13. In our database, we also indicated possible tectonic vertical land motion, and we present the results of GIA modelling for different areas in SE Asia. We also show regions of South East Asia and parts of the Indo-Pacific where there is an absence of data and where the collection of new RSL data is mostly needed.</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('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('https://www.osti.gov/scitech/biblio/6119181','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6119181"><span>Holocene sequence stratigraphy and <span class="hlt">sea</span> <span class="hlt">level</span> rise, south Florida margin</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Locker, S.D.; Hine, A.C.; Toscano, M.A. ); Shinn, E.A. )</p> <p>1993-03-01</p> <p>Fluctuation of late Quaternary <span class="hlt">sea</span> <span class="hlt">level</span> has been an important factor controlling erosional and depositional patterns on portions of the outer shelf and slope seaward of the lower-most Florida Keys. Studies in this area using high-resolution seismic, side scan sonar, bottom grab sampling, and submersible dives document a Holocene succession of lowstand wedge, transgressive, and highstand systems tract facies which have formed in response to <span class="hlt">sea</span> <span class="hlt">level</span> flooding the margin. The last lowstand of <span class="hlt">sea</span> <span class="hlt">level</span> is recorded by widespread scallop-like erosion along the slope front, occurring as deep as 150 m. Upslope from the erosional cuts, the transgressive systems tract includes a series of drowned shoreline (and reef) accumulations in the depth range 60--110 meters. Rocks recovered form paleoshorelines near 100 m water depth were submarine-cemented grainstones composed of early Holocene shallow-water carbonates. This transgressive section is partially buried by weakly laminated to reflection free fined-grained deposits of the highstand systems tract. These recent muddy silts reflect a sediment source initiated by flooding of the inner shelf platform and subsequent alongslope transport of fines exported offbank. Two very continuous, linear, and thin (< 5 m thick) paleoshorelines at 60--62 m and 66--68 m reflect a response to a change in rate of <span class="hlt">sea-level</span> rise across a low gradient surface. The deeper shoreline deposits, ranging from 75--110 m below <span class="hlt">sea</span> <span class="hlt">level</span> are isolated features and occur on steeper slopes. The character of preserved transgressive deposits suggests the Holocene rate of rise is punctuated. The lowest stand of <span class="hlt">sea</span> <span class="hlt">level</span> produced distinctive erosional features. Accretional transgressive deposits formed during the <span class="hlt">sea-level</span> rise. Interactions between antecedent topography, bottom currents, and changes in sediment supply, slope gradients, and rate of <span class="hlt">sea-level</span> rise are key factors controlling facies patterns, accumulation rates, and depositional geometries.</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> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110023308','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110023308"><span>Experiments in Reconstructing Twentieth-Century <span class="hlt">Sea</span> <span class="hlt">Levels</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ray, Richard D.; Douglas, Bruce C.</p> <p>2011-01-01</p> <p>One approach to reconstructing historical <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea</span>-surface heights from either satellite altimetry or a numerical ocean model. The problem is revisited here for <span class="hlt">sea</span> <span class="hlt">level</span> since 1900. A new approach to handling the tide-gauge datum problem by direct solution offers possible advantages over the method of integrating <span class="hlt">sea-level</span> differences, with the potential of eventually adjusting datums into the global terrestrial reference frame. The resulting time series of global mean <span class="hlt">sea</span> <span class="hlt">levels</span> appears fairly insensitive to the adopted set of EOFs. In contrast, charts of regional <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea-level</span> 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 <span class="hlt">sea-level</span> 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.</p> </li> <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://adsabs.harvard.edu/abs/2011AGUFM.G21B0812L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.G21B0812L"><span>Local <span class="hlt">Sea</span> <span class="hlt">Level</span> Derived from Reflected GNSS Signals</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Löfgren, J. S.; Haas, R.; Scherneck, H.; Bos, M. S.</p> <p>2011-12-01</p> <p>The traditional way to observe <span class="hlt">sea</span> <span class="hlt">level</span> is to use tide gauges, resulting in measurements relative to the Earth's crust. However, in order to measure the <span class="hlt">sea-level</span> change due to changes in ocean water volume and/or other oceanographic phenomena, all types of crustal motion at the measurement site need to be known. We present a remote sensing technique for measuring local <span class="hlt">sea</span> <span class="hlt">level</span> using standard geodetic-type Global Navigation Satellite System (GNSS) receivers. The installation consists of a zenith-looking Right Hand Circular Polarized (RHCP) antenna, receiving the direct signals, and a nadir-looking Left Hand Circular Polarized antenna, receiving the signals reflected of the <span class="hlt">sea</span> surface. Each antenna is connected to a receiver and the antenna pair is deployed back-to-back at a coastal site. Estimating the vertical baseline between the two antennas, using standard geodetic analysis, the local <span class="hlt">sea</span> <span class="hlt">level</span> and its temporal variations can be determined. The advantage of this technique is that it allows to measure both <span class="hlt">sea</span> surface height changes with relative positioning and land surface height changes, e.g., by precise point positioning of the RHCP antenna. Furthermore, the combined measurements of local <span class="hlt">sea</span> <span class="hlt">level</span> are automatically corrected for land motion, meaning that this installation could provide continuously reliable <span class="hlt">sea-level</span> estimates in tectonic active regions. This GNSS-based tide gauge has been operating continuously at the Onsala Space Observatory (OSO) on the west coast of Sweden since September 2010. We present results from several months of operations and compare them to <span class="hlt">sea-level</span> measurements from two stilling well gauges about 18 km south and 33 km north of OSO. We find a high degree of agreement between the time series with correlation coefficients of larger than 0.95. The root-mean-square differences between the GNSS-derived <span class="hlt">sea</span> <span class="hlt">level</span> and the stilling well gauge measurements are 5.9 cm and 5.5 cm, which is lower than between the two stilling well (6</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3871948','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3871948"><span>Impact of Altimeter Data Processing on <span class="hlt">Sea</span> <span class="hlt">Level</span> Studies</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Fernandes, M. Joana; Barbosa, Susana; Lázaro, Clara</p> <p>2006-01-01</p> <p>This study addresses the impact of satellite altimetry data processing on <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span> anomalies with respect to a mean <span class="hlt">sea</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span> trend determined from TOPEX altimetry is dependent on the adopted models for the major geophysical corrections. The main effects come from the <span class="hlt">sea</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span> trend, from 0.0 to 0.2 mm/yr, with a small latitude dependence. The difference in <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span> trend of about 0.1 mm/yr. The interannual signals of <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span> trend. These results strike the need for a continuous improvement in the modelling of the various effects that influence the altimeter measurement.</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/1994ChJOL..12..154C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994ChJOL..12..154C"><span>Mean <span class="hlt">sea</span> <span class="hlt">level</span> and <span class="hlt">sea</span> surface variability of northwest pacific ocean and eastern China <span class="hlt">seas</span> from Geosat altimetry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Ge; He, Ming-Xia; Masatoshi, Akiyama; Yasuhiro, Sugimori; Jun, Suwa</p> <p>1994-06-01</p> <p>Collinear analysis technique is widely used for determining <span class="hlt">sea</span> surface variability with Geosat altimeter data from its Exact Repeat Mission (ERM). But most of the researches have been only on global scale or in oceans deeper than 2000 m. In shallow shelf waters this method is hampered by the inaccuracy of ocean tide data supplied with Geosat Geophysical Data Records (GDRs). This work uses a modified collinear analysis technique characterized by simultaneous separation of mean <span class="hlt">sea</span> <span class="hlt">level</span> and ocean tide with the least squares method, to compute <span class="hlt">sea</span> surface variability in the Northwest Pacific Ocean and eastern China <span class="hlt">Seas</span>. The mean <span class="hlt">sea</span> <span class="hlt">level</span> map obtained contains not only bathymetric but also dynamic features such as amphidromes, indicating considerable improvement over previous works. Our <span class="hlt">sea</span> surface variability maps show clearly the main current system, the well-known Zhejiang coastal upwelling, and a northern East China <span class="hlt">Sea</span> meso-scale eddy in good agreement with satellite <span class="hlt">sea</span> surface temperature (SST) observation and historical in situ measurement. These all suggest that meaningful and reliable oceanographic results can still be achieved in shallow shelf waters from Geosat altimetry as long as proper data processing techniques are applied.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920048967&hterms=barometer&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dbarometer','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920048967&hterms=barometer&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dbarometer"><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('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/2016NLE.....5...37P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NLE.....5...37P"><span>Analysis of the <span class="hlt">sea</span> <span class="hlt">levels</span> in Kiribati A Rising <span class="hlt">Sea</span> of Misrepresentation Sinks Kiribati</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Parker, Albert</p> <p>2016-03-01</p> <p>The <span class="hlt">sea</span> <span class="hlt">levels</span> of Kiribati have been stable over the last few decades, as elsewhere in the world. The Australian government funded Pacific <span class="hlt">Sea</span> <span class="hlt">Level</span> Monitoring (PSLM) project has adjusted <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea</span> <span class="hlt">levels</span> 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014GeoJI.199.1018N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014GeoJI.199.1018N"><span>Simultaneous estimation of lithospheric uplift rates and absolute <span class="hlt">sea</span> <span class="hlt">level</span> change in southwest Scandinavia from inversion of <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>Nielsen, Lars; Hansen, Jens Morten; Hede, Mikkel Ulfeldt; Clemmensen, Lars B.; Pejrup, Morten; Noe-Nygaard, Nanna</p> <p>2014-11-01</p> <p>Relative <span class="hlt">sea</span> <span class="hlt">level</span> curves contain coupled information about absolute <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span> change from relative <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span> change rates for ancient times in areas where a dense coverage of relative <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span> change rates in southwest Scandinavia from modern relative <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span> rise values of ˜0.8/1.2 mm yr-1 (before</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.7156C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.7156C"><span>The Enigma of 20th century <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>Cathles, Larry</p> <p>2014-05-01</p> <p><span class="hlt">Sea</span> <span class="hlt">level</span> has been constant at near-present <span class="hlt">levels</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span> records that extend back to 1700 AD, and the impossibility of projecting the current <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span> rise. Our GIA model suggests no ocean mass increases (~0 mm/y of equivalent <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span> rise over the last 100 years with much smaller preceding <span class="hlt">sea</span> <span class="hlt">level</span> 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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4150292','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4150292"><span><span class="hlt">Sea</span> <span class="hlt">level</span>: measuring the bounding surfaces of the ocean</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Tamisiea, Mark E.; Hughes, Chris W.; Williams, Simon D. P.; Bingley, Richard M.</p> <p>2014-01-01</p> <p>The practical need to understand <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span>. Additional data sources, particularly satellite altimetry missions, have helped us to better identify the rates and causes of <span class="hlt">sea-level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span>. While information from many scientific disciplines is needed to understand <span class="hlt">sea-level</span> change, this review focuses on contributions from geodesy and the role of the ocean's bounding surfaces: the <span class="hlt">sea</span> surface and the Earth's crust. PMID:25157196</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25157196','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25157196"><span><span class="hlt">Sea</span> <span class="hlt">level</span>: measuring the bounding surfaces of the ocean.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tamisiea, Mark E; Hughes, Chris W; Williams, Simon D P; Bingley, Richard M</p> <p>2014-09-28</p> <p>The practical need to understand <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span>. Additional data sources, particularly satellite altimetry missions, have helped us to better identify the rates and causes of <span class="hlt">sea-level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span>. While information from many scientific disciplines is needed to understand <span class="hlt">sea-level</span> change, this review focuses on contributions from geodesy and the role of the ocean's bounding surfaces: the <span class="hlt">sea</span> surface and the Earth's crust.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012QSRv...40...54C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012QSRv...40...54C"><span>Quantitative constraints on the <span class="hlt">sea-level</span> fall that terminated the Littorina <span class="hlt">Sea</span> Stage, southern Scandinavia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Clemmensen, Lars B.; Murray, Andrew S.; Nielsen, Lars</p> <p>2012-04-01</p> <p>The island of Anholt in the Kattegat <span class="hlt">sea</span> (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 <span class="hlt">sea</span> <span class="hlt">level</span>. 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 <span class="hlt">sea-level</span>. Assuming a constant uplift rate of 1.2 mm/yr, the corresponding drop in absolute <span class="hlt">sea-level</span> is estimated to be around 2.6 m. This marked <span class="hlt">sea-level</span> 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 <span class="hlt">Sea</span> stage in the Baltic <span class="hlt">Sea</span> region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11.4734V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11.4734V"><span>Ice2<span class="hlt">sea</span> - the future glacial contribution to <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>Vaughan, D. G.; Ice2sea Consortium</p> <p>2009-04-01</p> <p>The melting of continental ice (glaciers, ice caps and ice sheets) is a substantial source of current <span class="hlt">sea-level</span> rise, and one that is accelerating more rapidly than was predicted even a few years ago. Indeed, the most recent report from Intergovernmental Panel on Climate Change highlighted that the uncertainty in projections of future <span class="hlt">sea-level</span> rise is dominated by uncertainty concerning continental ice, and that understanding of the key processes that will lead to loss of continental ice must be improved before reliable projections of <span class="hlt">sea-level</span> rise can be produced. Such projections are urgently required for effective <span class="hlt">sea</span>-defence management and coastal adaptation planning. Ice2<span class="hlt">sea</span> is a consortium of European institutes and international partners seeking European funding to support an integrated scientific programme to improve understanding concerning the future glacial contribution to <span class="hlt">sea-level</span> rise. This includes improving understanding of the processes that control, past, current and future <span class="hlt">sea-level</span> rise, and generation of improved estimates of the contribution of glacial components to <span class="hlt">sea-level</span> rise over the next 200 years. The programme will include targeted studies of key processes in mountain glacier systems and ice caps (e.g. Svalbard), and in ice sheets in both polar regions (Greenland and Antarctica) to improve understanding of how these systems will respond to future climate change. It will include fieldwork and remote sensing studies, and develop a suite of new, cross-validated glacier and ice-sheet model. Ice2<span class="hlt">sea</span> will deliver these results in forms accessible to scientists, policy-makers and the general public, which will include clear presentations of the sources of uncertainty. Our aim is both, to provide improved projections of the glacial contribution to <span class="hlt">sea-level</span> rise, and to leave a legacy of improved tools and techniques that will form the basis of ongoing refinements in <span class="hlt">sea-level</span> projection. Ice2<span class="hlt">sea</span> will provide exciting opportunities for many</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMOS31B2008P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMOS31B2008P"><span><span class="hlt">Sea</span> <span class="hlt">Level</span> Budget along the East Coast of North America</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pease, A. M.; Davis, J. L.; Vinogradova, N. T.</p> <p>2016-12-01</p> <p>We analyzed tide gauge data, taken from 1955 to 2015, from 29 locations along the east coast of North America. A well-documented period of <span class="hlt">sea-level</span> acceleration began around 1990. The <span class="hlt">sea</span> <span class="hlt">level</span> rate (referenced to epoch 1985.0) and acceleration (post-1990) are spatially and temporally variable, due to various physical processes, each of which is also spatially and temporally variable. To determine the <span class="hlt">sea-level</span> budgets for rate and acceleration, we considered a number of major contributors to <span class="hlt">sea</span> <span class="hlt">level</span> change: ocean density and dynamics, glacial isostatic adjustment (GIA), the inverted barometer effect, and mass change associated with the Greenland Ice Sheet (GIS) and the Antarctic Ice Sheet (AIS). The geographic variability in the budgets for <span class="hlt">sea-level</span> rate is dominated by GIA. At some sites, GIA is the largest contributor to the rate. The geographic variability in the budgets for <span class="hlt">sea-level</span> acceleration is dominated by ocean dynamics and density and GIS mass loss. The figure below shows budgets for <span class="hlt">sea-level</span> rate (left) and acceleration (right) for Key West, Fla., (top) and The Battery in New York City (bottom). The blue represents values (with error bar shown) estimated from tide gauge observations, and the yellow represents the total values estimated from the individual model contributions (each in red, green, cyan, pink, and black). The estimated totals for rate and acceleration are good matches to the tide-gauge inferences. To achieve a reasonable fit, a scaling factor (admittance) for the combined contribution of ocean dynamics and density was estimated; this admittance may reflect the low spatial sampling of the GECCO2 model we used, or other problems in modeling coastal <span class="hlt">sea-level</span>. The significant contributions of mass loss to the acceleration enable us to predict that, if such mass-loss continues or increases, the character of <span class="hlt">sea-level</span> change on the North American east coast will change in the next 50-100 years. In particular, whereas GIA presently</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://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/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://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/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/2000SSRv...93..207D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000SSRv...93..207D"><span><span class="hlt">Muon</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>Duldig, Marc L.</p> <p>2000-07-01</p> <p><span class="hlt">Muon</span> observations are complementary to neutron monitor observations but there are some important differences in the two techniques. Unlike neutron monitors, <span class="hlt">muon</span> telescope systems use coincidence techniques to obtain directional information about the arriving particle. Neutron monitor observations require simple corrections for pressure variations to compensate for the varying mass of atmospheric absorber over a site. In contrast, <span class="hlt">muon</span> observations require additional corrections for the positive and negative temperature effects. <span class="hlt">Muon</span> observations commenced many years before neutron monitors were constructed. Thus, <span class="hlt">muon</span> data over a larger number of solar cycles is available to study solar modulation on anisotropies and other cosmic ray variations. The solar diurnal and semi-diurnal variations have been studied for many years. Using the techniques of Bieber and Chen it has been possible to derive the radial gradient, parallel mean-free path and symmetric latitude gradient of cosmic rays for rigidities <200 GV. The radial gradient varies with the 11-year solar activity cycle whereas the parallel mean-free path appears to vary with the 22-year solar magnetic cycle. The symmetric latitudinal gradient reverses at each solar polarity reversal. These results are in general agreement with predictions from modulation models. In undertaking these analyses the ratio of the parallel to perpendicular mean-free path must be assumed. There is strong contention in the literature about the correct value to employ but the results are sufficiently robust for this to be, at most, a minor problem. An asymmetric latitude gradient of highly variable nature has been found. These observations do not support current modulation models. Our view of the sidereal variation has undergone a revolution in recent times. Nagashima, Fujimoto and Jacklyn proposed a narrow Tail-In source anisotropy and separate Loss-Cone anisotropy as being responsible for the observed variations. A new analysis</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://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> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013GPC...110...99C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013GPC...110...99C"><span>History of Aral <span class="hlt">Sea</span> <span class="hlt">level</span> variability and current scientific debates</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cretaux, Jean-François; Letolle, René; Bergé-Nguyen, Muriel</p> <p>2013-11-01</p> <p>The Aral <span class="hlt">Sea</span> has shrunk drastically over the past 50 years, largely due to water abstraction from the Amu Darya and Syr Darya rivers for land irrigation. Over a longer timescale, Holocene palaeolimnological reconstruction of variability in water <span class="hlt">levels</span> of the Aral <span class="hlt">Sea</span> since 11,700 BP indicates a long history of alternating phases of regression and transgression, which have been attributed variously to climate, tectonic and anthropogenic forcing. The hydrological history of the Aral <span class="hlt">Sea</span> has been investigated by application of a variety of scientific approaches, including archaeology, palaeolimnological palaeoclimate reconstruction, geophysics, sedimentology, and more recently, space science. Many issues concerning lake <span class="hlt">level</span> variability over the Holocene and more recent timescales, and the processes that drive the changes, are still a matter for active debate. Our aim in this article is to review the current debates regarding key issues surrounding the causes and magnitude of Aral <span class="hlt">Sea</span> <span class="hlt">level</span> variability on a variety of timescales from months to thousands of years. Many researchers have shown that the main driving force of Aral <span class="hlt">Sea</span> regressions and transgressions is climate change, while other authors have argued that anthropogenic forcing is the main cause of Aral <span class="hlt">Sea</span> water <span class="hlt">level</span> variations over the Holocene. Particular emphasis is made on contributions from satellite remote sensing data in order to improve our understanding of the influence of groundwater on the current hydrological water budget of the Aral <span class="hlt">Sea</span> since 2005. Over this period of time, water balance computation has been performed and has shown that the underground water inflow to the Aral <span class="hlt">Sea</span> is close to zero with an uncertainty of 3 km3/year.</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/26319030','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26319030"><span>How Much Are Floridians Willing to Pay for Protecting <span class="hlt">Sea</span> Turtles from <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>Hamed, Ahmed; Madani, Kaveh; Von Holle, Betsy; Wright, James; Milon, J Walter; Bossick, Matthew</p> <p>2016-01-01</p> <p><span class="hlt">Sea</span> <span class="hlt">level</span> rise (SLR) is posing a great inundation risk to coastal areas. Some coastal nesting species, including <span class="hlt">sea</span> 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 <span class="hlt">sea</span> 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 <span class="hlt">sea</span> 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 <span class="hlt">sea</span> 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 <span class="hlt">sea</span> turtle habitat. The greatest indicators of whether or not an individual was willing to pay to protect <span class="hlt">sea</span> 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 <span class="hlt">sea</span> turtles having an effect on their life were also more likely to pay.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EnMan..57..176H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EnMan..57..176H"><span>How Much Are Floridians Willing to Pay for Protecting <span class="hlt">Sea</span> Turtles from <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>Hamed, Ahmed; Madani, Kaveh; Von Holle, Betsy; Wright, James; Milon, J. Walter; Bossick, Matthew</p> <p>2016-01-01</p> <p><span class="hlt">Sea</span> <span class="hlt">level</span> rise (SLR) is posing a great inundation risk to coastal areas. Some coastal nesting species, including <span class="hlt">sea</span> 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 <span class="hlt">sea</span> 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 <span class="hlt">sea</span> 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 <span class="hlt">sea</span> 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 <span class="hlt">sea</span> turtle habitat. The greatest indicators of whether or not an individual was willing to pay to protect <span class="hlt">sea</span> 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 <span class="hlt">sea</span> turtles having an effect on their life were also more likely to pay.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014OcScD..11.1519L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014OcScD..11.1519L"><span><span class="hlt">Sea</span> <span class="hlt">level</span> trend and variability around the 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>Luu, Q. H.; Tkalich, P.; Tay, T. W.</p> <p>2014-06-01</p> <p>Peninsular Malaysia is bounded from the west by Malacca Strait and the Andaman <span class="hlt">Sea</span> both connected to the Indian Ocean, and from the east by South China <span class="hlt">Sea</span> being largest marginal <span class="hlt">sea</span> in the Pacific Basin. Resulting <span class="hlt">sea</span> <span class="hlt">level</span> along Peninsular Malaysia coast is assumed to be governed by various regional phenomena associated with the adjacent parts of the Indian and Pacific Oceans. At annual scale, <span class="hlt">sea</span> <span class="hlt">level</span> anomalies (SLAs) are generated by the Asian monsoon; interannual <span class="hlt">sea</span> <span class="hlt">level</span> variability is determined by the El Niño-Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD); while long-term <span class="hlt">sea</span> <span class="hlt">level</span> trend is related to global climate change. To quantify the relative impacts of these multi-scale phenomena on <span class="hlt">sea</span> <span class="hlt">level</span> trend and variability around the Peninsular Malaysia, long-term tide gauge record and satellite altimetry are used. During 1984-2011, relative <span class="hlt">sea</span> <span class="hlt">level</span> rise (SLR) rates in waters of Malacca Strait and eastern Peninsular Malaysia are found to be 2.4 ± 1.6 mm yr-1 and 2.7 ± 1.0 mm yr-1, respectively. Allowing for corresponding vertical land movements (VLM; 0.8 ± 2.6 mm yr-1 and 0.9 ± 2.2 mm yr-1), their absolute SLR rates are 3.2 ± 4.2 mm yr-1 and 3.6 ± 3.2 mm yr-1, respectively. For the common period 1993-2009, absolute SLR rates obtained from both tide gauge and satellite altimetry in Peninsular Malaysia are similar; and they are slightly higher than the global tendency. It further underlines that VLM should be taken into account to get better estimates of SLR observations. At interannual scale, ENSO affects <span class="hlt">sea</span> <span class="hlt">level</span> over the Malaysian coast in the range of ±5 cm with a very high correlation. Meanwhile, IOD modulates <span class="hlt">sea</span> <span class="hlt">level</span> anomalies mainly in the Malacca Strait in the range of ±2 cm with a high correlation coefficient. Interannual regional <span class="hlt">sea</span> <span class="hlt">level</span> drops are associated with El Niño events and positive phases of the IOD index; while the rises are correlated with La Niña episodes and the negative periods of the IOD index</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('https://ntrs.nasa.gov/search.jsp?R=19830041107&hterms=global+climate+change&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dglobal%2Bclimate%2Bchange','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19830041107&hterms=global+climate+change&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dglobal%2Bclimate%2Bchange"><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('https://www.osti.gov/scitech/biblio/6533694','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6533694"><span>Local <span class="hlt">sea</span> <span class="hlt">level</span> change and future of Louisiana coast</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Nummedal, D.</p> <p>1983-09-01</p> <p>The relative elevation of <span class="hlt">sea</span> and land has been changing through time in response to two fundamentally different groups of factors. Global factors include changes in the volume of the ocean basins owing to tectonic processes and changes in the total amount of ocean water due to glaciation. Local factors include subsidence of continental margins and compaction of recent sediments. Over this century, global <span class="hlt">sea</span> <span class="hlt">level</span> (eustatic) appears to have been rising at a rate of 1.2 mm per year. Along the south-central Louisiana coast the land surface appears to be sinking at a rate of about 8 mm per year. Recent global climatic modeling suggests strongly that we are about to enter a period of rapidly accelerating warming due to increased amount of carbon dioxide in the atmosphere. As a consequence, eustatic <span class="hlt">sea</span> <span class="hlt">level</span> rise is predicted to accelerate because of both steric expansion of the ocean water and continued melting of polar ice caps. For the next 40 years the eustatic <span class="hlt">sea</span> <span class="hlt">level</span> rise may average 10 mm per year. The local relative <span class="hlt">sea</span> <span class="hlt">level</span> in coastal Louisiana would therefore rise at about twice its present rate over this time period. The numbers presented above are average value for the Louisiana coastal plain. Local variability in subsidence rate appear to be related to the thickness of Holocene sediments. The highest rates of subsidence are found in the modern Mississippi (birdfoot) delta and in coastal Terrebonne Parish above the late Pleistocene Mississippi trench; in both areas the Holocene section is in excess of 200 m (650 ft) thick. The high rate of local <span class="hlt">sea</span> <span class="hlt">level</span> rise along the Louisiana coast makes it imperative that plans for coastal development and protection consider the long-term consequences of <span class="hlt">sea</span> <span class="hlt">level</span> change.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016Ocgy...56....6M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016Ocgy...56....6M"><span>Spectrum of mesoscale <span class="hlt">sea</span> <span class="hlt">level</span> oscillations in the northern Black <span class="hlt">Sea</span>: Tides, seiches, and inertial oscillations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Medvedev, I. P.; Kulikov, E. A.</p> <p>2016-01-01</p> <p>Long-term data from 23 tide gauges were used to analyze the spectrum of mesoscale <span class="hlt">sea</span> <span class="hlt">level</span> variability of the Black <span class="hlt">Sea</span>. The tides have sharp spectral peaks, and they are detected at diurnal and semidiurnal frequencies for all stations. A local wide spectral peak associated with inertial oscillations is located between the diurnal and semidiurnal tidal peaks. This peak is well known in the spectra of the current velocity variations of the Black <span class="hlt">Sea</span>, but in the <span class="hlt">sea</span> <span class="hlt">level</span> spectrum it has been identified for the first time. At frequencies of >3 cpd, <span class="hlt">sea</span> <span class="hlt">level</span> spectra of the Black <span class="hlt">Sea</span> have (1) wide maxima in the continuous spectrum, which correspond to the main eigenmodes of the <span class="hlt">sea</span> with periods of 5.6, 4.8, 4.1, and 3.1 h, and (2) sharp peaks of radiational harmonics S3, S4, S5, and S6. The periods of seiches calculated in this study are close to the periods of eigenmodes of the Black <span class="hlt">Sea</span>, obtained by the numerical modeling of other authors. The main factors influencing the formation of radiational tides in the Black <span class="hlt">Sea</span> are presumably breezes and runoff from large rivers. The significant predominance of a harmonic with frequency of 5 cpd (S5) over other radiational harmonics is caused by the influence of an eigenmode, with a frequency of about 5 cpd. The proximity of the periods of these oscillations leads to resonant amplification and to a corresponding increase in amplitude of the radiational harmonic S5.</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/2017EGUGA..19.4526B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.4526B"><span>Holocene <span class="hlt">sea</span> <span class="hlt">level</span>, a semi-empirical contemplation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bittermann, Klaus; Kemp, Andrew; Vermeer, Martin; Rahmstorf, Stefan</p> <p>2017-04-01</p> <p>Holocene eustatic <span class="hlt">sea</span> <span class="hlt">level</span> from approximately -10,000-1800 CE was characterized by an increase of about 60 m, with the rate progressively slowing down until <span class="hlt">sea</span> <span class="hlt">level</span> almost stabilizes between 500-1800 CE. Global and northern-hemisphere temperatures rose from the last glacial termination until the 'Holocene Optimum'. From there, up to the start of the recent anthropogenic rise, they almost steadily decline. How are the <span class="hlt">sea-level</span> and temperature evolutions linked? We investigate this with a semi-empirical <span class="hlt">sea-level</span> model. We found that, due to the nature of Milankovitch forcing, northern-hemisphere temperature (we used the Greenland temperature by Vinther et al., 2009) is a better model driver than global mean temperature because the evolving mass of northern-hemisphere land ice was the dominant cause of Holocene global <span class="hlt">sea-level</span> trends. The adjustment timescale for this contribution is 1200 years (900-1500 years; 90% confidence interval). To fit the observed <span class="hlt">sea-level</span> history, the model requires a small additional constant rate (Bittermann 2016). This rate turns out to be of the same order of magnitude as reconstructions of Antarctic <span class="hlt">sea-level</span> contributions (Briggs et al. 2014, Golledge et al. 2014). In reality this contribution is unlikely to be constant but rather has a dominant timescale that is large compared to the time considered. We thus propose that Holocene <span class="hlt">sea</span> <span class="hlt">level</span> can be described by a linear combination of a temperature driven rate, which becomes negative in the late Holocene (as Northern Hemisphere ice masses are diminished), and a positive, approximately constant term (possibly from Antarctica), which starts to dominate from the middle of the Holocene until the start of industrialization. Bibliography: Bittermann, K. 2016. Semi-empirical <span class="hlt">sea-level</span> modelling. PhD Thesis University of Potsdam. Briggs, R.D., Pollard, D., & Tarasov, L. 2014. A data-constrained large ensemble analysis of Antarctic evolution since the Eemian. Quaternary science reviews</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> </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('http://adsabs.harvard.edu/abs/2013EGUGA..15.1547V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.1547V"><span>Ice2<span class="hlt">sea</span> - tackling uncertainty in projections 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>Vaughan, David</p> <p>2013-04-01</p> <p>The future security and prosperity of our growing coastal cities and survival of many unique coastal habitats requires scientists to deliver reliable <span class="hlt">sea-level</span> projections, which will form the basis of protection and adaptation planning for vulnerable coastal regions. Most contributions to <span class="hlt">sea-level</span> rise can now be predicted with some confidence; the greatest remaining uncertainty lies in the contribution of ice-loss from Antarctica and Greenland. An EU Framework-7 programme, ice2<span class="hlt">sea</span>, is working to inform the IPCC Fifth Assessment, and provide policy-makers with reliable <span class="hlt">sea-level</span> projections, taking account of the long response-times of ice sheets and the complex atmospheric and oceanic changes that impact them. The collective efforts of 24 partners in Europe and overseas to the ice2<span class="hlt">sea</span> have produced projections of the contribution of global glaciers and ice sheets to <span class="hlt">sea-level</span> rise, using process-based models tied to specific emissions scenarios. These projections are synthesised here, with identification of geographical areas and processes where uncertainty is significantly reduced, and others where potential for future reduction remain urgently required.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995ECSS...40....1S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995ECSS...40....1S"><span>Seasonal variations of the <span class="hlt">sea</span> <span class="hlt">level</span> in the central part of the Red <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>Sultan, S. A. R.; Ahmad, F.; El-Hassan, A.</p> <p>1995-01-01</p> <p>Seasonal <span class="hlt">sea-level</span> changes at two coastal stations, Jeddah and Port Sudan, display higher <span class="hlt">levels</span> in winter and lower <span class="hlt">levels</span> in summer, showing a coherence over a distance of 300 km. The amplitude of these changes is slightly higher at Jeddah compared with that of Port Sudan. Analysis of wind stress indicates that the cross-shore component plays a dominant role in the <span class="hlt">sea-level</span> changes at Port Sudan in contrast to Jeddah where a major part of the changes can be accounted for by the long-shore component.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18832639','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18832639"><span>A chronology of Paleozoic <span class="hlt">sea-level</span> changes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Haq, Bilal U; Schutter, Stephen R</p> <p>2008-10-03</p> <p><span class="hlt">Sea</span> <span class="hlt">levels</span> have been determined for most of the Paleozoic Era (542 to 251 million years ago), but an integrated history of <span class="hlt">sea</span> <span class="hlt">levels</span> has remained unrealized. We reconstructed a history of <span class="hlt">sea-level</span> fluctuations for the entire Paleozoic by using stratigraphic sections from pericratonic and cratonic basins. Evaluation of the timing and amplitude of individual <span class="hlt">sea-level</span> events reveals that the magnitude of change is the most problematic to estimate accurately. The long-term <span class="hlt">sea</span> <span class="hlt">level</span> shows a gradual rise through the Cambrian, reaching a zenith in the Late Ordovician, then a short-lived but prominent withdrawal in response to Hirnantian glaciation. Subsequent but decreasingly substantial eustatic highs occurred in the mid-Silurian, near the Middle/Late Devonian boundary, and in the latest Carboniferous. Eustatic lows are recorded in the early Devonian, near the Mississippian/Pennsylvanian boundary, and in the Late Permian. One hundred and seventy-two eustatic events are documented for the Paleozoic, varying in magnitude from a few tens of meters to approximately 125 meters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMOS23D..07B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMOS23D..07B"><span>Impact of internal climate memory on 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>Becker, M.; Karpytchev, M.; Hu, A.; Deser, C.; Lennartz-Sassinek, S.</p> <p>2016-12-01</p> <p>Estimating the magnitude of <span class="hlt">sea</span> <span class="hlt">level</span> rise (SLR) for the end of 21st century is among the primary goals of current climate research. An important practical aspect of this problem is that any projection of the SLR is obtained with uncertainty, which is partly due to internal variability of the Earth climate system. This internal variability is due to complex non-linear interactions within the Earth climate system and can induce diverse quasi-periodic oscillatory modes and a long-term memory behavior. It has been demonstrated that the interplay of long-term memory fluctuations in <span class="hlt">sea</span> <span class="hlt">level</span> changes can be modeled by a power-law process. Therefore, this makes possible the uncertainty estimations in <span class="hlt">sea</span> <span class="hlt">level</span> trends caused by the internal variability. The obvious question is whether the long-memory of the internal variability is correctly simulated in climate models. In this study, we (1) analyze the scaling behaviour of the <span class="hlt">sea</span> <span class="hlt">level</span> fluctuations projected for the 21st century by the National Center for Atmospheric Research Community Climate System Model (NCAR-CCSM) and (2) compare the uncertainties in predicated <span class="hlt">sea</span> <span class="hlt">level</span> changes obtained from a NCAR-CCSM multi-member ensemble simulations with estimates derived from the Lennartz-Bunde statistics for the power-law processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017GeoJI.210.1264M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017GeoJI.210.1264M"><span>Vertical land motion and <span class="hlt">sea</span> <span class="hlt">level</span> change in Macaronesia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mendes, V. B.; Barbosa, S. M.; Romero, I.; Madeira, J.; Brum da Silveira, A.</p> <p>2017-08-01</p> <p>This study addresses long-term <span class="hlt">sea</span> <span class="hlt">level</span> variability in Macaronesia from a holistic perspective using all available instrumental records in the region, including a dense network of GPS continuous stations, tide gauges and satellite observations. A detailed assessment of vertical movement from GPS time series underlines the influence of the complex volcano-tectonic setting of the Macaronesian islands in local uplift/subsidence. Relative <span class="hlt">sea</span> <span class="hlt">level</span> for the region is spatially highly variable, ranging from -1.1 to 5.1 mm yr-1. Absolute <span class="hlt">sea</span> <span class="hlt">level</span> from satellite altimetry exhibits consistent trends in the Macaronesia, with a mean value of 3.0 ± 0.5 mm yr-1. Typically, <span class="hlt">sea</span> <span class="hlt">level</span> trends from tide gauge records corrected for vertical movement using the estimates from GPS time series are lower than uncorrected estimates. The agreement between satellite altimetry and tide gauge trends corrected for vertical land varies substantially from island to island. Trends derived from the combination of GPS and tide gauge observations differ by less than 1 mm yr-1 with respect to absolute <span class="hlt">sea</span> <span class="hlt">level</span> trends from satellite altimetry for 56 per cent of the stations, despite the heterogeneity in length of both GPS and tide gauge series, and the influence of volcanic-tectonic processes affecting the position of some GPS stations.</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('http://adsabs.harvard.edu/abs/2003EOSTr..84...13L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EOSTr..84...13L"><span><span class="hlt">Sea</span> <span class="hlt">level</span> and coastal erosion require large-scale monitoring</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Leatherman, Stephen P.; Douglas, Bruce C.; LaBrecque, John L.</p> <p></p> <p>There is a coastward migration of the world's population, which is occurring at the same time as rising <span class="hlt">sea</span> <span class="hlt">level</span> and shoreline recession; this is the definition of a collision course. Rates of beach erosion along the U.S. east coast average slightly less than a meter per year, putting expensive beachfront development at risk to storm impact. Global <span class="hlt">sea</span> <span class="hlt">levels</span> have risen about 20 cm in the last century; relative rates of rise have more than doubled this amount in some areas due to land subsidence. Future <span class="hlt">sea</span> <span class="hlt">levels</span> are projected to rise significantly faster than occurred in the 20th century, resulting in acceleration of the present rate of shore recession. There is much debate about future rates of <span class="hlt">sea</span> <span class="hlt">level</span> rise, and even some disagreement about the historical rate based on analysis of tide gauge records [IPCC, 2001; Douglas etal, 2001]. An array of satellites are providing the requisite measurements to determine global <span class="hlt">sea</span> <span class="hlt">level</span> changes in concert with tide gauges and terrestrial references. At the same time, new technologies such as airborne and spaceborne laser mapping are beginning to provide the data sets necessary for three-dimensional monitoring of shoreline changes.</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('https://eric.ed.gov/?q=sea+AND+level&pg=4&id=EJ328737','ERIC'); return false;" href="https://eric.ed.gov/?q=sea+AND+level&pg=4&id=EJ328737"><span><span class="hlt">Sea</span> <span class="hlt">Level</span> Change, A Fundamental Process When Interpreting Coastal Geology and Geography.</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>Zeigler, John M.</p> <p>1985-01-01</p> <p>Discusses the meaning of <span class="hlt">sea</span> <span class="hlt">level</span> change and identifies the major factors responsible for this occurrence. Elaborates on the theory and processes involved in indirect measurement of changes in <span class="hlt">sea</span> volume. Also explains how crustal movement affects <span class="hlt">sea</span> <span class="hlt">level</span>. (ML)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=sea+AND+level&pg=4&id=EJ328737','ERIC'); return false;" href="http://eric.ed.gov/?q=sea+AND+level&pg=4&id=EJ328737"><span><span class="hlt">Sea</span> <span class="hlt">Level</span> Change, A Fundamental Process When Interpreting Coastal Geology and Geography.</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>Zeigler, John M.</p> <p>1985-01-01</p> <p>Discusses the meaning of <span class="hlt">sea</span> <span class="hlt">level</span> change and identifies the major factors responsible for this occurrence. Elaborates on the theory and processes involved in indirect measurement of changes in <span class="hlt">sea</span> volume. Also explains how crustal movement affects <span class="hlt">sea</span> <span class="hlt">level</span>. (ML)</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/2017EGUGA..1918337N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1918337N"><span><span class="hlt">Sea-level</span> rise risks to coastal cities</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nicholls, Robert J.</p> <p>2017-04-01</p> <p>Understanding the consequence of <span class="hlt">sea-level</span> rise for coastal cities has long lead times and huge political implications. Civilisation has emerged and developed during a period of several thousand years during which in geological terms <span class="hlt">sea</span> <span class="hlt">level</span> has been unusually stable. We have now moved out of this period and the challenge will be to develop a long-term proactive assessment approach to manage this challenge. In 2005 there were 136 coastal cities with a population exceeding one million people and a collective population of 400 million people. All these coastal cities are threatened by flooding from the <span class="hlt">sea</span> to varying degrees and these risks are increasing due to growing exposure (people and assets), rising <span class="hlt">sea</span> <span class="hlt">levels</span> due to climate change, and in some cities, significant coastal subsidence due to human agency (drainage and groundwater withdrawals from susceptible soils). In these cities we wish to avoid major flood events, with associated damage and potentially deaths and ultimately decline of the cities. Flood risks grow with <span class="hlt">sea-level</span> rise as it raises extreme <span class="hlt">sea</span> <span class="hlt">levels</span>. As <span class="hlt">sea</span> <span class="hlt">levels</span> continue to rise, protection will have to be progressively upgraded. Even with this, the magnitude of losses when flood events do occur would increase as coastal cities expand, and water depths and hence unit damage increase with <span class="hlt">sea-level</span> rise/subsidence. This makes it critical to also prepare for larger coastal flood disasters than we experience today and raises questions on the limits to adaptation. There is not an extensive literature or significant empirical information on the limits to adaptation in coastal cities. These limits are not predictable in a formal sense - while the rise in mean <span class="hlt">sea</span> <span class="hlt">level</span> raises the likelihood of a catastrophic flood, extreme events are what cause damage and trigger a response, be it abandonment, a defence upgrade or something else. There are several types of potential limits that could be categorised into three broad types: • Physical</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMPP13B2115L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMPP13B2115L"><span><span class="hlt">Sea</span> <span class="hlt">Level</span> Variations During Snowball Earth Formation: A Preliminary Analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Y.; Peltier, W. R.</p> <p>2012-12-01</p> <p>The <span class="hlt">sea</span> <span class="hlt">level</span> changes that would have accompanied the "Snowball Earth" events of the Late Neoproterozoic (1000 Ma - 540 Ma) have remained enigmatic. Emplacement of the voluminous ice sheets on the continents during these events should have drawn down eustatic <span class="hlt">sea</span> <span class="hlt">level</span> by ~1000 m but geological evidence of this having actually occurred is scant. The only reliable estimate is apparently that based upon observations from the Otavi Group in Northern Namibia (Hoffman et al. (2007), Earth Planet Sc Lett, 258(1-2), 114-131, doi:10.1016/j.epsl.2007.03.032) which indicates a <span class="hlt">sea</span> <span class="hlt">level</span> change of approximately 500 m to have occurred. In this work, we provide a preliminary theoretical estimate of the extent to which the ocean surface could have fallen with respect to the continents during such snowball Earth events. Our analyses are performed by solving the <span class="hlt">Sea</span> <span class="hlt">Level</span> Equation for a spherically symmetric Maxwell Earth subject to extensive continental glaciation for a realistic land-<span class="hlt">sea</span> distribution. We find, as expected, that the fall of relative <span class="hlt">sea</span> <span class="hlt">level</span> must have been highly non-uniform, with the collapse of the geoid least near the coastal regions and greatest in the ocean basin interiors. For a 720 Ma (Sturtian) continental configuration, the ice sheet volume in a snowball state is ~824 m <span class="hlt">sea</span> <span class="hlt">level</span> equivalent, but ocean surface lowering (relative to the original surface) can be as little as ~300 m near the coast of a continental fragment that was host of a major ice dome. Although the mean water depth (relative <span class="hlt">sea</span> <span class="hlt">level</span>) is reduced by ~824 m, because the mean elevation of the ocean floor is increased by ~193 m, the mean ocean surface fall is only ~631 m. The change of continental freeboard (which may be recorded in the sedimentary record) at the edge of the continents is usually larger than the lowering of ocean surface due to the forebulge effect, ranging from 400 - 600 m. For the 570 Ma (Marinoan) continental configuration, ice sheet volumes is ~1180 m in eustatic <span class="hlt">sea</span></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://www.youtube.com/watch?v=dWz3s9OIIZQ','SCIGOVIMAGE-NASA'); return false;" href="http://www.youtube.com/watch?v=dWz3s9OIIZQ"><span>NASA Now: Climate Change: <span class="hlt">Sea</span> <span class="hlt">Level</span> Rise</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p></p> <p>Dr. Josh Willis discusses the connection between oceans and global climate change. Learn why NASA measures greenhouse gases and how we detect ocean <span class="hlt">levels</span> from space. These are crucial vital signs ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMNH53A3857T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMNH53A3857T"><span><span class="hlt">Sea-Level</span> Anomalies Facilitate Beach Erosion and Increase Barrier Island Vulnerability to Storms and <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>Theuerkauf, E. J.; Rodriguez, A. B.; Fegley, S. R.; Luettich, R. A., Jr.</p> <p>2014-12-01</p> <p><span class="hlt">Sea-level</span> anomalies are intra-seasonal (weeks to months) periods of high water <span class="hlt">level</span> induced by oceanographic and meteorological processes, such as reduced Gulf Stream transport strength or persistent northeasterly winds. Although flooding associated with <span class="hlt">sea-level</span> anomalies has been documented along continental coastlines (e.g. U.S. East Coast), these phenomena are not presently included in coastal models and management plans. We present the first measurements of beach erosion after a year with frequent <span class="hlt">sea-level</span> anomalies. Erosion during this year, which was not impacted by large storms, was similar to a year with a hurricane, indicating that <span class="hlt">sea-level</span> anomalies are important facilitators of coastal erosion. Beach erosion was measured at Onslow Beach, NC (OB) in a year with frequent <span class="hlt">sea-level</span> anomalies (2009-2010) and compared to erosion during a year with no major events (2010-2011) and the year with Hurricane Irene (2011-2012). <span class="hlt">Sea-level</span> anomalies were identified in water <span class="hlt">level</span> data from a NOAA tide gauge in Wrightsville Beach, NC. From 2009-2010 anomalously high <span class="hlt">sea</span> <span class="hlt">level</span> occurred ~40% of the time, compared to ~8% from 2010-2011 and ~10% from 2011-2012. Significant wave heights, measured from an acoustic wave and current profiler and NOAA buoys offshore of OB, were not statistically different among these 3 years. The average backshore, high intertidal, and mid intertidal maximum depth of erosion for all sites along OB in the year with frequent <span class="hlt">sea-level</span> anomalies were ~25, 50, and 55 cm, respectively. These values are greater than those measured after the year with no major events (~13, 29, and 32 cm) and similar to those measured after the year with Hurricane Irene (~27, 49, and 40 cm). OB has high along-strike variability in barrier island morphology, thus results apply to many beaches and barrier islands. Our results suggest that anomalies are important mechanisms of coastal change and likely amplify erosion in response to accelerated <span class="hlt">sea-level</span> rise and</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('https://eric.ed.gov/?q=carbon+AND+dioxide+AND+levels&pg=2&id=EJ290512','ERIC'); return false;" href="https://eric.ed.gov/?q=carbon+AND+dioxide+AND+levels&pg=2&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> </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://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/2005GMS...161..111D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005GMS...161..111D"><span>Gulf of Mexico and Atlantic coast <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>Douglas, Bruce C.</p> <p></p> <p>Twentieth-century relative <span class="hlt">sea</span> <span class="hlt">level</span> rise shows considerable variability along the U.S. East and Gulf coasts. Local rates of rise lie in the range of about 1.5 to more than 4 mm per year for records from Key West, Florida, to New York City. Rates of <span class="hlt">sea</span> <span class="hlt">level</span> rise in the Gulf of Mexico can be much higher. In Texas and Louisiana, long-term water <span class="hlt">levels</span> are rising up to about 10 mm per year. This is having disastrous consequences in the form of wetlands loss in the region, estimated to be as much as 65 km2 per year in the Mississippi Delta area of Louisiana alone. Beach erosion is also significant along both the Gulf and Atlantic coasts, resulting in ever-increasing exposure of fixed structures to the damaging impacts of storms. The especially high rates of <span class="hlt">sea</span> <span class="hlt">level</span> rise in Louisiana and Texas are a result of their particular geomorphology, and anthropogenic alterations in the form of sediment diversion and withdrawal of underground fluids. The average long-term local rate of <span class="hlt">sea</span> <span class="hlt">level</span> rise on the rest of the U.S. East and Gulf coasts when corrected for glacial isostatic adjustment is about 2 mm per year, in conformity with 20th century global <span class="hlt">sea</span> <span class="hlt">level</span> rise. U.S. East and Gulf coast tide gauge records also have regionally coherent low frequency (decadal and longer) variations that need to be understood because of their impact on wetlands loss, and to enable accurate determination of long-term trends of <span class="hlt">sea</span> <span class="hlt">level</span> rise.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19850027714','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850027714"><span><span class="hlt">Muons</span> in gamma showers</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stanev, T.; Vankov, C. P.; Halzen, F.</p> <p>1985-01-01</p> <p><span class="hlt">Muon</span> production in gamma-induced air showers, accounting for all major processes. For <span class="hlt">muon</span> energies in the GeV region the photoproduction is by far the most important process, while the contribution of micron + micron pair creation is not negligible for TeV <span class="hlt">muons</span>. The total rate of <span class="hlt">muons</span> in gamma showers is, however, very low.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17..445M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17..445M"><span>Tracking multidecadal trends in <span class="hlt">sea</span> <span class="hlt">level</span> using coral microatolls</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Majewski, Jedrzej; Pham, Dat; Meltzner, Aron; Switzer, Adam; Horton, Benjamin; Heng, Shu Yun; Warrick, David</p> <p>2015-04-01</p> <p>Tracking multidecadal trends in <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea-level</span> change at multidecadal timescales associated with vertical land movements, climate induced <span class="hlt">sea-level</span> rise and other oceanographic phenomena such as the El Niño/Southern Oscillation (ENSO) or Indian Ocean Dipole (IOD) with the assumption that the highest <span class="hlt">level</span> of survival (HLS) of coral microatolls track <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea-level</span> 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 <span class="hlt">sea-level</span> reconstructions for 1950-2011. The <span class="hlt">sea-level</span> 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 <span class="hlt">levels</span> at multi decadal time scales and can be used as a proxy for relative <span class="hlt">sea</span> <span class="hlt">level</span> (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</p> </li> <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://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> <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://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('https://ntrs.nasa.gov/search.jsp?R=19770059848&hterms=tsunami&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dtsunami','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19770059848&hterms=tsunami&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dtsunami"><span>A <span class="hlt">sea-level</span> recorder for tectonic studies</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bilham, R.</p> <p>1977-01-01</p> <p>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 <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span>. 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 <span class="hlt">sea-level</span> recorders have been installed in seismic gaps in the Aleutians and in the Caribbean.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950046393&hterms=sea+level&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dsea%2Blevel','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950046393&hterms=sea+level&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dsea%2Blevel"><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/2016GeoRL..43.6478W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoRL..43.6478W"><span>A new perspective on global mean <span class="hlt">sea</span> <span class="hlt">level</span> (GMSL) acceleration</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>2016-06-01</p> <p>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 <span class="hlt">sea</span> <span class="hlt">level</span>. By virtue, over recent years, the issue of whether or not there is a measurable acceleration in global mean <span class="hlt">sea</span> <span class="hlt">level</span> has resulted in fierce, widespread professional, social, and political debate. Attempts to measure acceleration in global mean <span class="hlt">sea</span> <span class="hlt">level</span> (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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014GeoRL..41.5530D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014GeoRL..41.5530D"><span>Evidence for long-term memory in <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>Dangendorf, Sönke; Rybski, Diego; Mudersbach, Christoph; Müller, Alfred; Kaufmann, Edgar; Zorita, Eduardo; Jensen, Jürgen</p> <p>2014-08-01</p> <p>Detection and attribution of anthropogenic climate change signals in <span class="hlt">sea</span> <span class="hlt">level</span> rise (SLR) has experienced considerable attention during the last decades. Here we provide evidence that superimposed on any possible anthropogenic trend there is a significant amount of natural decadal and multidecadal variability. Using a set of 60 centennial tide gauge records and an ocean reanalysis, we find that <span class="hlt">sea</span> <span class="hlt">levels</span> exhibit long-term correlations on time scales up to several decades that are independent of any systematic rise. A large fraction of this long-term variability is related to the steric component of <span class="hlt">sea</span> <span class="hlt">level</span>, but we also find long-term correlations in current estimates of mass loss from glaciers and ice caps. These findings suggest that (i) recent attempts to detect a significant acceleration in regional SLR might underestimate the impact of natural variability and (ii) any future regional SLR threshold might be exceeded earlier/later than from anthropogenic change alone.</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/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('http://adsabs.harvard.edu/abs/2017GeoRL..44.8953H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017GeoRL..44.8953H"><span>Detection of <span class="hlt">sea</span> <span class="hlt">level</span> fingerprints derived from GRACE gravity data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hsu, Chia-Wei; Velicogna, Isabella</p> <p>2017-09-01</p> <p>Mass changes of ice sheets, glaciers and ice caps, land water hydrology, atmosphere, and ocean cause a nonuniform <span class="hlt">sea</span> <span class="hlt">level</span> rise due to the self-attraction and loading effects called <span class="hlt">sea</span> <span class="hlt">level</span> fingerprints (SLF). SLF have been previously derived from a combination of modeled and observed mass fluxes from the continents into the ocean. Here we derive improved SLF from time series of time variable gravity data from the Gravity Recovery and Climate Experiment (GRACE) mission for April 2002 to October 2014. We evaluate the GRACE-derived SLF using ocean bottom pressure (OBP) data from stations in the tropics, where OBP errors are the lowest. We detect the annual phase of the SLF in the OBP signal and separate it unambiguously from the barystatic <span class="hlt">sea</span> <span class="hlt">level</span> (BSL) at two stations. At the basin scale, the SLF explain a larger fraction of the variance in steric-corrected altimetry than the BSL, which has implications for evaluating mass transport between ocean basins.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=rising+AND+sea+AND+levels&id=EJ389555','ERIC'); return false;" href="https://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://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/2017ThApC.129..129O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ThApC.129..129O"><span>Investigation of <span class="hlt">sea</span> <span class="hlt">level</span> trends and the effect of the north atlantic oscillation (NAO) on the black <span class="hlt">sea</span> and the eastern 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>Ozgenc Aksoy, Aysegul</p> <p>2017-07-01</p> <p>The North Atlantic Oscillation (NAO) has significant effects on <span class="hlt">sea</span> <span class="hlt">levels</span>, weather, and climate. In this study, the <span class="hlt">sea</span> <span class="hlt">level</span> trends and the effects of the North Atlantic Oscillation Indices (NAOI) on annual mean <span class="hlt">sea</span> <span class="hlt">level</span> data were assessed for the Black <span class="hlt">Sea</span> and the Eastern Mediterranean <span class="hlt">Sea</span>. The trends of <span class="hlt">sea</span> <span class="hlt">level</span> and NAOI were determined using Mann-Kendall dimensionless z statistics. Generally, upward <span class="hlt">sea</span> <span class="hlt">level</span> trends were detected for the Black <span class="hlt">Sea</span> and the Eastern Mediterranean <span class="hlt">Sea</span>. In the Black <span class="hlt">Sea</span>, significant and continuous upward trends were detected after the year 1950. Weaker trends were detected for the Eastern part of the Mediterranean <span class="hlt">Sea</span>. <span class="hlt">Sea</span> <span class="hlt">level</span> trends were correlated with trends in NAO indices; negative correlations were detected for the Black <span class="hlt">Sea</span>, whereas positive correlations were found for the Eastern Mediterranean <span class="hlt">Sea</span>. Paired t tests were performed to determine the turning points for all <span class="hlt">sea</span> <span class="hlt">level</span> data sets. The value of t was positive for all data sets, which means that the mean value of the data set before the turning point was smaller than the mean value of the data set after the turning point.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950049105&hterms=sea+level&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dsea%2Blevel','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950049105&hterms=sea+level&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dsea%2Blevel"><span>Comparison of TOPEX <span class="hlt">sea</span> surface heights and tide gauge <span class="hlt">sea</span> <span class="hlt">levels</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mitchum, Gary T.</p> <p>1994-01-01</p> <p>TOPEX <span class="hlt">sea</span> surface height data from the first 300 days of the mission are compared to <span class="hlt">sea</span> <span class="hlt">level</span> data from 71 tide gauges. The initial comparison uses <span class="hlt">sea</span> surface height data processed according to standard procedures as defined in the users handbook. It is found that the median correlations for island and for coastal tide gauges are 0.53 and 0.42, respectively. The analogous root mean square (RMS) differences between the two data sets are 7.9 and 10.4 cm. The comparisons improve significantly when a 60-day harmonic is fit to the differences and removed. This period captures aliased M(sub 2) and S(sub 2) tidal energy that is not removed by the tide model. Making this correction and smoothing the <span class="hlt">sea</span> surface height data over 25-km along-track segments results in median correlations of 0.58 and 0.46 for the islands and coastal stations, and median RMS differences of 5.8 and 7.7 cm, respectively. Removing once per revolution signals from the <span class="hlt">sea</span> surface heights results in degraded comparisons with the <span class="hlt">sea</span> <span class="hlt">levels</span>. It is also found that a number of stations have poor comparisons due to propagating signals that introduce temporal lags between the altimeter and tide gauge time series. A final comparison is made by eliminating stations where this propagation effect is large, discarding two stations that are suspected to have problems with the <span class="hlt">sea</span> <span class="hlt">level</span> data, smoothing over 10-day intervals, and restricting attention to islands gauges. This results in a set of 552 data pairs that have a correlation of 0.66 and a RMS difference of 4.3 cm. The conclusion is that on timescales longer than about 10 days the RMS <span class="hlt">sea</span> surface height errors are less than or of the order of several centimeters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMOS13A1794M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMOS13A1794M"><span>Interannual <span class="hlt">sea</span> <span class="hlt">level</span> variability in the Eastern Indian Ocean and Southern 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>Mohan, S. S.; Vethamony, P.</p> <p>2016-12-01</p> <p><span class="hlt">Sea</span> <span class="hlt">level</span> anomalies (SLAs) derived from satellite observations (over a period of 21 years) and tide gauge data compiled from 24 stations from the Eastern Indian Ocean (EIO) and southern South China <span class="hlt">Sea</span> (SCS) have been analysed to study the inter-annual variability of SLAs in the EIO and southern SCS. To examine the seasonality in interannual variability, 3 months to 7 years band pass filtered non-seasonal SLAs were considered. A large fraction of interannual SLA variability in the south eastern SCS is linked to ENSO and rest of the region is characterized by small scale interannual variations. Analysis of both tide gauge and altimetry data confirms that interannual <span class="hlt">sea</span> <span class="hlt">level</span> anomalies in the SCS shows seasonality with pronounced variation occurring during winter and fall seasons. Both tide gauge and altimetry data show that 40% of interannual SLAs at Malacca Strait and southeastern SCS and 50% at Java <span class="hlt">Sea</span> could be explained by both ENSO and IOD. Malacca Strait and Java <span class="hlt">Sea</span> SLAs at interannual scale show coherent variability with that of eastern equatorial Indian Ocean. Regional correlation pattern and Wavelet power spectrum of SLAs at Java <span class="hlt">Sea</span> shows similar dominant periodicities as in the Malacca Strait. Strong oscillations associated with climate modes are centered at 2-5 year period. Interannual SLAs at southeastern SCS show the importance of western Pacific on <span class="hlt">sea</span> <span class="hlt">level</span> modulation through the Luzon and Mindoro Straits. Wind variations largely explain the interannual SLA variation in the EIO and southern SCS. Interannual zonal wind variations in the equatorial Indian Ocean induce SLA variations in the Malacca Strait and Java <span class="hlt">Sea</span>. Remote and local winds that drive interannual variability of SLAs in the EIO and southeastern SCS are associated with both ENSO and IOD events.</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/2016AGUFMOS23D..06K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMOS23D..06K"><span>Regional <span class="hlt">sea-level</span> projections: Drivers of uncertainty</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kopp, R. E.</p> <p>2016-12-01</p> <p>Much of the focus of <span class="hlt">sea-level</span> rise projections is on global mean <span class="hlt">sea</span> <span class="hlt">level</span> (GMSL) rise, yet no one lives at the global mean. Interpreting records of past <span class="hlt">sea-level</span> changes and projecting future changes require an understanding of the relationships between GMSL and regional relative <span class="hlt">sea</span> <span class="hlt">level</span> (RSL) (e.g., [1]). Differences between the two are attributable to four types of processes: (1) those associated with shifts in atmospheric and ocean dynamics and in regional ocean density anomalies; (2) those associated with the shifting of mass between the cryosphere or terrestrial hydrosphere and the ocean; (3) natural processes independent of contemporary climate change, associated with factors such as glacial-isostatic adjustment, sediment compaction, and tectonics; and (4) anthropogenic processes independent of contemporary climate change, associated with factors such as groundwater and hydrocarbon withdrawal. Historically, deviations of RSL change from GMSL change have been dominated by atmospheric/ocean dynamic processes (#1) on annual to decadal timescales, and by geological processes (#3) on millennial timescales. Projecting forward, the growing cryospheric contribution to <span class="hlt">sea-level</span> rise implies an increasingly important role for land-ice changes (#2) on regional RSL variability over decadal to millennial timescales. Probabilistic frameworks for <span class="hlt">sea-level</span> rise projections (e.g. [2]) provide a quantitative basis for assessing the relative importance over different timescales of different contributors to uncertainty in (a) RSL rise at a particular location, (b) the deviation of RSL rise from GMSL, and (c) the growth of local flood risk as a result of RSL rise. This talk presents examples of regional uncertainty decomposition and its use in identifying key research directions. References: 1. R. E. Kopp et al. (2015). Current Climate Change Reports 1, 192-204. doi:10.1007/s40641-015-0015-5.2. R. E. Kopp et al. (2014). Earth's Future 2, 287-306, doi:10.1002/2014EF000239.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMGC21C1101K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMGC21C1101K"><span>Attribution of Annual Maximum <span class="hlt">Sea</span> <span class="hlt">Levels</span> to Tropical Cyclones</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Khouakhi, A.; Villarini, G.</p> <p>2015-12-01</p> <p>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 <span class="hlt">sea</span> <span class="hlt">levels</span> is therefore essential. In this work we examine the contribution of TCs to annual maximum <span class="hlt">sea</span> <span class="hlt">levels</span> 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 <span class="hlt">Sea</span> <span class="hlt">Level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea</span> <span class="hlt">levels</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhDT........35A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhDT........35A"><span>Final <span class="hlt">muon</span> cooling for a <span class="hlt">muon</span> collider</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Acosta Castillo, John Gabriel</p> <p></p> <p>To explore the new energy frontier, a new generation of particle accelerators is needed. <span class="hlt">Muon</span> colliders are a promising alternative if <span class="hlt">muon</span> cooling can be made to work. <span class="hlt">Muons</span> are 200 times heavier than electrons, so they produce less synchrotron radiation, and they behave like point particles. However, they have a short lifetime of 2.2 mus and the beam is more difficult to cool than an electron beam. The <span class="hlt">Muon</span> Accelerator Program (MAP) was created to develop concepts and technologies required by a <span class="hlt">muon</span> collider. An important effort has been made in the program to design and optimize a <span class="hlt">muon</span> beam cooling system. The goal is to achieve the small beam emittance required by a <span class="hlt">muon</span> collider. This work explores a final ionization cooling system using magnetic quadrupole lattices with a low enough beta* region to cool the beam to the required limit with available low Z absorbers.</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/2016AGUFMOS12A..01K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMOS12A..01K"><span>Separating steric <span class="hlt">sea</span> <span class="hlt">level</span> and ocean bottom pressure in the Tropical Asian <span class="hlt">Seas</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kleinherenbrink, M.; Riva, R.; Frederikse, T.</p> <p>2016-12-01</p> <p>Direct observations of Ocean Bottom Pressure (OBP) in the Tropical Asian <span class="hlt">Seas</span> (TAS) are normally avoided due to a cut-off of typically 300 km in GRACE gravity fields from the coast to limit hydrological leakage.The limited number of temperature and salinity observations lead to interpolation problems and make it difficult to infer steric changes in the region.To close the <span class="hlt">sea</span> <span class="hlt">level</span> budget in the tropical ocean using Argo, GRACE and altimetry, the TAS area is therefore omitted (Von Schuckmann et al., 2014).However, due to its large <span class="hlt">sea</span> <span class="hlt">level</span> trends, the omission of the TAS in global <span class="hlt">sea</span> <span class="hlt">level</span> budgets leads to an underestimation of 0.5 mm/yr between 2005-2011 (Von Schuckmann et al., 2014).Furthermore, no studies exist to date that separate total <span class="hlt">sea</span> <span class="hlt">level</span> into the steric and OBP components, which in combination with large bathymetry fluctuations, hampers the understanding of the dynamics causing interannual variability in <span class="hlt">sea</span> <span class="hlt">level</span> in the area. We separate the steric and OBP components in the TAS, using altimetry, optimally filtered ITSG-Grace2016 gravity fields and temperature and salinity grids from various ocean reanalyses.By combining the observations from the three sources in a statistically optimal way, we aim to get the best separation of OBP and steric <span class="hlt">sea</span> <span class="hlt">level</span>.The sum of the OBP and steric <span class="hlt">sea</span> <span class="hlt">level</span> trends is statistically equal to trend differences caused by omitting the TAS, which makes it possible to correct global <span class="hlt">sea</span> <span class="hlt">level</span> budgets.Secondly, the interannual variability is mostly captured by regression with the El-Nino Southern Oscillation (ENSO) 3.4 index.In the deeper regions of the TAS this is primarily a steric signal, however in the shallow areas the interannual signal is of OBP origin.Finally, a large fraction of the OBP trends in the TAS region is explained by trends derived from fingerprints of Greenland, Anarctic, and glacier melt as well as dam retention and land hydrology plus a contribution of the nodal cycle.However, especially in the</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/2017E%26SS....4..138M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017E%26SS....4..138M"><span>Coherence between <span class="hlt">sea</span> <span class="hlt">level</span> oscillations and orbital perturbations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mawad, Ramy</p> <p>2017-03-01</p> <p><span class="hlt">Sea</span> <span class="hlt">level</span> rising and oscillations indicate global Earth's mass variability. I propose inflow of mass to the Earth from space through coronal mass ejections, solar wind, small comets, and meteoroids that brings water to Earth's atmosphere. Outflow mass can also escape plasma into space. <span class="hlt">Sea</span> <span class="hlt">level</span> rising is highly correlated with Earth's orbital perturbations. Monthly and annual periodicities are found in the two variables. Monthly periodicities are attributed to the oscillations of center of gravity of the Earth-Moon system as the Moon revolves around the Earth. Annual periodicities are found with minimum in February and maximum in November, pointing to mass variability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19890054519&hterms=SEA+POWER&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DSEA%2BPOWER','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19890054519&hterms=SEA+POWER&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DSEA%2BPOWER"><span>Pulse compression and <span class="hlt">sea</span> <span class="hlt">level</span> tracking in satellite altimetry</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chelton, Dudley B.; Walsh, Edward J.; Macarthur, John L.</p> <p>1989-01-01</p> <p>An account is given of the pulse-compression technique, in which a radar altimeter transmits a relatively long pulse and processes the returned signal in a way equivalent to transmitting a very short one and measuring the returned power in a sequence of range gates. The effective short pulse enhances the range resolution that would be obtained from the actual long pulse. Pulse compression and <span class="hlt">sea-level</span> tracking are important to the overall error budget for altimetric estimates of <span class="hlt">sea</span> <span class="hlt">level</span>. Attention is presently given to the high degree of accuracy required for the NASA TOPEX altimeter scheduled for launch in mid-1992.</p> </li> <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/2016AGUFM.H53B1698S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.H53B1698S"><span>Land <span class="hlt">Sea</span> <span class="hlt">Level</span> Difference Impacts on Socio-Hydrological System.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sung, K.; Yu, D. J.; Oh, W. S.; Sangwan, N.</p> <p>2016-12-01</p> <p>Allowing moderate shocks can be a new solution that helps to build adaptive capacity in society is a rising issue. In Social-Ecological field, Carpenter et al. (2015) suggested that exposure to short-term variability leads to long term resilience by enlarging safe operating space (SOS). The SOS refers to the boundary of favorable state that ecosystem can maintain resilience without imposing certain conditions (Carpenter et al. 2015). Our work is motivated by defining SOS in socio-hydrological system(SHS) because it can be an alternative way for flood management beyond optimized or robust flood control. In this context, large flood events that make system to cross the SOS should be fully managed, but frequent small floods need to be allowed if the system is located in SOS. Especially, land <span class="hlt">sea</span> <span class="hlt">level</span> change is critical factor to change flood resilience since it is one of the most substantial disturbance that changes the entire boundary of SOS. In order to have broader perspective of vulnerability and resilience of the coastal region, it is crucial to understand the land <span class="hlt">sea</span> <span class="hlt">level</span> dynamics changed with human activities and natural variances.The risk of land <span class="hlt">sea</span> <span class="hlt">level</span> change has been researched , but most of these researches have focused on explain cause and effect of land <span class="hlt">sea</span> <span class="hlt">level</span> change, paying little attention to its dynamics interacts with human activities. Thus, an objective of this research is to study dynamics of human work, land <span class="hlt">sea</span> <span class="hlt">level</span> change and resilience to flood with SOS approach. Especially, we focus on the case in Ganges-Brahmaputra, Bangladesh where has high vulnerability to flood, and is faced with relatively rapid land <span class="hlt">sea</span> <span class="hlt">level</span> change problem. To acheive the goal, this study will develop a stylized model by extending the human - flood interaction model combined with relative <span class="hlt">sea</span> <span class="hlt">level</span> difference equation. The model describes the dynamics of flood protection system which is changed by SHS and land <span class="hlt">sea</span> <span class="hlt">level</span> chage. we will focus on the aggradation</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/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://adsabs.harvard.edu/abs/2017EGUGA..1914422L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1914422L"><span>Cyclones leading to positive and negative <span class="hlt">sea</span> <span class="hlt">level</span> extremes 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>Lionello, Piero; Conte, Dario; Reale, Marco</p> <p>2017-04-01</p> <p>This study describes the strong link between cyclones crossing the Mediterranean region and <span class="hlt">sea</span> <span class="hlt">level</span> extremes, which are mainly caused by a pressure-induced redistribution of water within the basin, though wind plays a substantial role in shallow water areas (mainly in the Gulf of Gabes and North Adriatic <span class="hlt">Sea</span>). Cyclones produce positive and negative anomalies in different parts of the basin, depending on their positions and tracks. For example, cyclones entering from the Atlantic Ocean domain produce initially positive <span class="hlt">sea</span> <span class="hlt">level</span> anomalies and successively, as they continue moving along the Mediterranean branch of the storm track, negative anomalies at several coastal stations in the western Mediterranean. Cyclones generated in the Western Mediterranean cause positive <span class="hlt">sea</span> <span class="hlt">level</span> anomalies along most of the basin coastline, but negative anomalies along the northwestern coast. The link between cyclone position and <span class="hlt">sea</span> <span class="hlt">level</span> anomaly is evident for both positive and negative events, but the dependence of the magnitude of the anomaly on the value of the low-pressure minimum is much stronger for the former than for the latter.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015OcScD..12..551P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015OcScD..12..551P"><span>Accelerated <span class="hlt">sea</span> <span class="hlt">level</span> rise and Florida Current transport</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Park, J.; Sweet, W.</p> <p>2015-04-01</p> <p>The Florida Current is the headwater of the Gulf Stream and is a component of the North Atlantic western boundary current from which a geostrophic balance between <span class="hlt">sea</span> surface height and mass transport directly influence coastal <span class="hlt">sea</span> <span class="hlt">levels</span> along the Florida Straits. A linear regression of daily Florida Current transport estimates does not find a significant change in transport over the last decade, however, a nonlinear trend extracted from empirical mode decomposition suggests a 3 Sv decline in mean transport. This decline is consistent with observed tide gauge records in Florida Bay and the Straits, all exhibiting an acceleration of mean <span class="hlt">sea</span> <span class="hlt">level</span> rise over the decade. It is not known whether this recent change represents natural variability or the onset of the anticipated secular decline in Atlantic meridional overturning circulation, nonetheless, such changes have direct impacts on the sensitive ecological systems of the Everglades as well as the climate of western Europe and eastern North America.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015OcSci..11..607P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015OcSci..11..607P"><span>Accelerated <span class="hlt">sea</span> <span class="hlt">level</span> rise and Florida Current transport</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Park, J.; Sweet, W.</p> <p>2015-07-01</p> <p>The Florida Current is the headwater of the Gulf Stream and is a component of the North Atlantic western boundary current from which a geostrophic balance between <span class="hlt">sea</span> surface height and mass transport directly influence coastal <span class="hlt">sea</span> <span class="hlt">levels</span> along the Florida Straits. A linear regression of daily Florida Current transport estimates does not find a significant change in transport over the last decade; however, a nonlinear trend extracted from empirical mode decomposition (EMD) suggests a 3 Sv decline in mean transport. This decline is consistent with observed tide gauge records in Florida Bay and the straits exhibiting an acceleration of mean <span class="hlt">sea</span> <span class="hlt">level</span> (MSL) rise over the decade. It is not known whether this recent change represents natural variability or the onset of the anticipated secular decline in Atlantic meridional overturning circulation (AMOC); nonetheless, such changes have direct impacts on the sensitive ecological systems of the Everglades as well as the climate of western Europe and eastern North America.</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('http://adsabs.harvard.edu/abs/2015EGUGA..17.5134U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.5134U"><span>Steric <span class="hlt">sea</span> <span class="hlt">level</span> change in the Bay of Bengal: investigating the most variable component of <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>Uebbing, Bernd; Kusche, Jürgen; Rietbroek, Roelof; Shum, Ck</p> <p>2015-04-01</p> <p>Regional <span class="hlt">sea</span> <span class="hlt">level</span> change is influenced by contributions from mass sources, like melting of glaciers and the ice-sheets in Greenland and Antarctica, as well as steric contributions from changes in temperature and salinity of the oceans. Radar altimetry indicates a <span class="hlt">sea</span> <span class="hlt">level</span> trend in the Bay of Bengal of about 6 mm- yr over the time period of 2002-2014, which is significantly larger than the global mean trend. Here, we explain 80% of this rise by steric contributions and 20% by mass-related contributions. The increased rise of <span class="hlt">sea</span> <span class="hlt">level</span> in the Bay of Bengal threatens the coastal vulnerability of the surrounding countries like Bangladesh, where this effect is exacerbated in combination with land subsidence of the very low lying coastal areas. The BanD-AID (Bangladesh Delta: Assessment of the Causes of <span class="hlt">Sea-level</span> Rise Hazards and Integrated Development of Predictive Modeling Towards Mitigation and Adaptation) project tries to assess the current and future <span class="hlt">sea</span> <span class="hlt">level</span> rise and its impacts on the people living in the threatened coastal areas. As a part of this, it is necessary to analyze the different mass and steric contributors to the total <span class="hlt">sea</span> <span class="hlt">level</span> rise to aid in the prediction of future risks. We use data from radar altimetry and the GRACE mission to separate the total <span class="hlt">sea</span> <span class="hlt">level</span> rise into contributions from mass sources and steric changes. In our approach, temporal GRACE gravity data and Jason-1 and -2 along track altimetry data are fitted to time invariant spatial patterns (fingerprints) to avoid problems with GRACE resolution, filtering, geocenter and related issues. Our results show that in the Bay of Bengal the steric component is influenced by annual and interannual phenomena and, at the same time, it is significantly larger compared to the individual mass contributions, which show a linear and relatively stable behavior over time. We validate the steric component of our inversion by comparing it to independent steric estimates from 4-D gridded temperature and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFM.G51A0146M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFM.G51A0146M"><span>Monitoring <span class="hlt">Sea</span> <span class="hlt">Level</span> At L'Estartit, Spain</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.; Ortiz Castellon, M.; Martinez-Garcia, M.; Talaya, J.; Rodriguez Velasco, G.; Perez, B.</p> <p>2007-12-01</p> <p><span class="hlt">Sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea-level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span>, 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 <span class="hlt">sea</span> heights at centimetre <span class="hlt">level</span>, 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 <span class="hlt">sea</span></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('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('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://adsabs.harvard.edu/abs/2002EGSGA..27.2961T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002EGSGA..27.2961T"><span>The Offlap Break Position Vs <span class="hlt">Sea</span> <span class="hlt">Level</span>: A Discussion</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tropeano, M.; Pieri, P.; Pomar, L.; Sabato, L.</p> <p></p> <p>Sedimentary lithosomes with subhorizontal topsets, basinward prograding foresets and subhorizontal bottomsets are common in the geologic record, and most of them display similar bedding architectures and/or seismic reflection patterns (i.e. Gylbert- type deltas and shelf wedges). Nevertheless, in shallow marine settings these bodies may form in distinct sedimentary environments and they result from different sed- imentary processes. The offlap break (topset edge) occurs in relation to the posi- tion of baselevel and two main groups of lithosomes can be differentiated with re- spect to the position of the offlap break within the shelf profile. The baselevel of the first group is the <span class="hlt">sea</span> <span class="hlt">level</span> (or lake <span class="hlt">level</span>); the topsets are mainly composed by continental- or very-shallow-water sedimentary facies and the offlap break practi- cally corresponds to the shoreline. Exemples of these lithosomes are high-constructive deltas (river-dominated deltas) and prograding beaches. For the second group, base- <span class="hlt">level</span> corresponds to the base of wave/tide traction, and their topsets are mostly composed by shoreface/nearshore deposits. Examples of these lithosomes are high- destructive deltas (wave/tide-dominated deltas) and infralittoral prograding wedges (i.e Hernandez-Molina et al., 2000). The offlap break corresponds to the shelf edge (shoreface edge), which is located at the transition between nearshore and offshore set- tings, where a terrace prodelta- or transition-slope may develop (Pomar &Tropeano, 2001). Two main problems derive from these alternative interpretations of shallow- marine seaward prograding lithosomes: 1) both in ancient sedimentary shallow-marine successios (showing seaward prograding foresets) and in high resolution seismic pro- files (showing shelf wedges), the offlap break is commonly considered to correspond to the <span class="hlt">sea-level</span> (shoreline) and used to inferr paleo <span class="hlt">sea-level</span> positions and to construct <span class="hlt">sea-level</span> curves. Without a good facies control, this use of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFMIN51B0400S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFMIN51B0400S"><span><span class="hlt">Sea</span> <span class="hlt">Level</span> Station Metadata for Tsunami Detection, Warning and Research</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stroker, K. J.; Marra, J.; Kari, U. S.; Weinstein, S. A.; Kong, L.</p> <p>2007-12-01</p> <p>The devastating earthquake and tsunami of December 26, 2004 has greatly increased recognition of the need for water <span class="hlt">level</span> data both from the coasts and the deep-ocean. In 2006, the National Oceanic and Atmospheric Administration (NOAA) completed a Tsunami Data Management Report describing the management of data required to minimize the impact of tsunamis in the United States. One of the major gaps defined in this report is the access to global coastal water <span class="hlt">level</span> data. NOAA's National Geophysical Data Center (NGDC) and National Climatic Data Center (NCDC) are working cooperatively to bridge this gap. NOAA relies on a network of global data, acquired and processed in real-time to support tsunami detection and warning, as well as high-quality global databases of archived data to support research and advanced scientific modeling. In 2005, parties interested in enhancing the access and use of <span class="hlt">sea</span> <span class="hlt">level</span> station data united under the NOAA NCDC's Integrated Data and Environmental Applications (IDEA) Center's Pacific Region Integrated Data Enterprise (PRIDE) program to develop a distributed metadata system describing <span class="hlt">sea</span> <span class="hlt">level</span> stations (Kari et. al., 2006; Marra et.al., in press). This effort started with pilot activities in a regional framework and is targeted at tsunami detection and warning systems being developed by various agencies. It includes development of the components of a prototype <span class="hlt">sea</span> <span class="hlt">level</span> station metadata web service and accompanying Google Earth-based client application, which use an XML-based schema to expose, at a minimum, information in the NOAA National Weather Service (NWS) Pacific Tsunami Warning Center (PTWC) station database needed to use the PTWC's Tide Tool application. As identified in the Tsunami Data Management Report, the need also exists for long-term retention of the <span class="hlt">sea</span> <span class="hlt">level</span> station data. NOAA envisions that the retrospective water <span class="hlt">level</span> data and metadata will also be available through web services, using an XML-based schema. Five high</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003EAEJA.....3643P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA.....3643P"><span>from radar measurement to <span class="hlt">sea</span> <span class="hlt">level</span> forecats</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Picot, N.; Toumazou, V.; Vincent, P.; Noubel, J.</p> <p>2003-04-01</p> <p>A new single ground segment for the DORIS/Spot, DORIS/(TOPEX/POSEIDON -T/P-, Jason, ENVISAT, CRYOSAT) missions has been built to operate DORIS instruments and altimetry payloads that fly simultaneously on different satellites and to satisfy users’ common needs. This is the goal of the SSALTO multi-mission altimetry, orbit determination and location ground segment to answer these needs, and more specifically to ensure that the expertise acquired in the frame of one mission enriches the other ones. For each single altimetry mission, the classical <span class="hlt">level</span> 2 products, namely the I/GDRs (Interim/Geophysical Data Records), are regularly produced, extensively checked through various techniques (crossover and along-track analysis, etc.) and distributed to the users. More importantly, SSALTO is also generating coherent multi-mission products in the near-real time and off-line modes. Indeed, the SSALTO multi-mission ground segment now includes the DUACS service historically developed by the CLS team in the frame of a European programme. DUACS has demonstrated that altimeter data can be processed in near real time with sufficient accuracy to help improving the skill of climate simulations and, more specially, seasonal climate forecasts. The near-real time (NRT) and historical products developed and refined by DUACS are now widely used in the scientific community. They cover a large spectrum of operational oceanography needs, from mesoscale to climate applications. SSALTO will continue DUACS to serve operational oceanography and climate forecasting projects. This is a key input for MERCATOR system. The MERCATOR-Ocean french project produces a weekly bulletin since January 17, 2001 providing a two-week forecast : this operational oceanography system describes, analyses and predicts conditions at the ocean surface and subsurface in real time, anytime, anywhere in the world, at global, basin or regional scale. MERCATOR-Ocean is the french contribution to the international GODAE</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/2010TCry....4..621B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010TCry....4..621B"><span>The <span class="hlt">sea</span> <span class="hlt">level</span> fingerprint of recent ice mass fluxes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bamber, J.; Riva, R.</p> <p>2010-12-01</p> <p>The <span class="hlt">sea</span> <span class="hlt">level</span> contribution from glacial sources has been accelerating during the first decade of the 21st Century (Meier et al., 2007; Velicogna, 2009). This contribution is not distributed uniformly across the world's oceans due to both oceanographic and gravitational effects. We compute the <span class="hlt">sea</span> <span class="hlt">level</span> signature for ice mass fluxes due to changes in the gravity field, Earth's rotation and related effects for the nine year period 2000-2008. Mass loss from Greenland results in a relative <span class="hlt">sea</span> <span class="hlt">level</span> (RSL) reduction for much of North Western Europe and Eastern Canada. RSL rise from this source is concentrated around South America. Losses in West Antarctica marginally compensate for this and produce maxima along the coastlines of North America, Australia and Oceania. The combined far-field pattern of wastage from all ice melt sources, is dominated by losses from the ice sheets and results in maxima at latitudes between 20° N and 40° S across the Pacific and Indian Oceans, affecting particularly vulnerable land masses in Oceania. The spatial pattern of RSL variations from ice mass losses used in this study is time-invariant and cumulative. Thus, <span class="hlt">sea</span> <span class="hlt">level</span> rise, based on the gravitational effects from the ice losses considered here, will be amplified for this sensitive region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011EOSTr..92..455C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011EOSTr..92..455C"><span>Was pre-twentieth century <span class="hlt">sea</span> <span class="hlt">level</span> stable?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cronin, Thomas M.</p> <p>2011-12-01</p> <p><span class="hlt">Sea</span> <span class="hlt">level</span> rise (SLR) ranks high on the list of climate change issues because the expected acceleration from the current rate (about 3.1 millimeters per year) poses threats to coastal regions. Tide gauge, salt marsh, and archaeological records, and modeling of glacioisostatic adjustment (GIA) have led to the widely accepted idea that late Holocene (the past ˜2000 years) <span class="hlt">sea</span> <span class="hlt">level</span> was stable prior to acceleration beginning around 1850-1900 C.E. For instance, according to the Intergovernmental Panel on Climate Change Fourth Assessment Report, before the last century, <span class="hlt">sea</span> <span class="hlt">level</span> had "stabilized" over the past 2000 years, rising at a mean rate of 0-0.2 millimeter per year [Bindoff et al., 2007]. Others maintain that <span class="hlt">sea</span> <span class="hlt">level</span> was "nearly stable" over the past few thousand years [Nicholls and Cazenave, 2010], pre-twentieth century rates were "close to zero" [Church et al., 2008], or "stable from at least BC 100 until AD 950" and "stable, or slightly falling" from 1350 until the nineteenth century [Kemp et al., 2011].</p> </li> <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/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> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1912716G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1912716G"><span>Annual mean <span class="hlt">sea</span> <span class="hlt">level</span> and its sensitivity to wind climate</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gerkema, Theo; Duran Matute, Matias</p> <p>2017-04-01</p> <p>Changes in relative mean <span class="hlt">sea</span> <span class="hlt">level</span> affect coastal areas in various ways, such as the risk of flooding, the evolution of barrier island systems, or the development of salt marshes. Long-term trends in these changes are partly masked by variability on shorter time scales. Some of this variability, for instance due to wind waves and tides (with the exception of long-period tides), is easily averaged out. In contrast, inter-annual variability is found to be irregular and large, of the order of several decimeters, as is evident from tide gauge records. This is why the climatic trend, typically of a few millimeters per year, can only be reliably identified by examining a record that is long enough to outweigh the inter-annual and decadal variabilities. In this presentation we examine the relation between the annual wind conditions from meteorological records and annual mean <span class="hlt">sea</span> <span class="hlt">level</span> along the Dutch coast. To do this, we need reliable and consistent long-term wind records. Some wind records from weather stations in the Netherlands date back to the 19th century, but they are unsuitable for trend analysis because of changes in location, height, surroundings, instrument type or protocol. For this reason, we will use only more recent, homogeneous wind records, from the past two decades. The question then is whether such a relatively short record is sufficient to find a convincing relation with annual mean <span class="hlt">sea</span> <span class="hlt">level</span>. It is the purpose of this work to demonstrate that the answer is positive and to suggest methods to find and exploit such a relation. We find that at the Dutch coast, southwesterly winds are dominant in the wind climate, but the west-east direction stands out as having the highest correlation with annual mean <span class="hlt">sea</span> <span class="hlt">level</span>. For different stations in the Dutch Wadden <span class="hlt">Sea</span> and along the coast, we find a qualitatively similar pattern, although the precise values of the correlations vary. The inter-annual variability of mean <span class="hlt">sea</span> <span class="hlt">level</span> can already be largely explained by</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/2016EGUGA..1812016S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1812016S"><span>Uncertainty estimates of altimetric Global Mean <span class="hlt">Sea</span> <span class="hlt">Level</span> timeseries</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Scharffenberg, Martin; Hemming, Michael; Stammer, Detlef</p> <p>2016-04-01</p> <p>An attempt is being presented concerned with providing uncertainty measures for global mean <span class="hlt">sea</span> <span class="hlt">level</span> time series. For this purpose <span class="hlt">sea</span> 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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008GeCar..34..109J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008GeCar..34..109J"><span>Geoid Profiles in the Baltic <span class="hlt">Sea</span> Determined Using GPS and <span class="hlt">Sea</span> <span class="hlt">Level</span> Surface</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jürgenson, Harli; Liibusk, Aive; Ellmann, Artu</p> <p>2008-12-01</p> <p>The idea was to compare the geoid of <span class="hlt">sea</span> areas by an independent method, like GPS <span class="hlt">levelling</span>, on the mainland. On the earth surface we can compare the gravimetric geoid with GPS <span class="hlt">levelling</span> to get an accuracy estimation and tilt information. On the <span class="hlt">sea</span> we can do it by the GPS methodology and eliminating the current water tilt corrections and the <span class="hlt">sea</span> 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 <span class="hlt">level</span>'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 <span class="hlt">Sea</span> 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 <span class="hlt">level</span> 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 <span class="hlt">level</span> surface is a very complex issue; special studies of that were conducted as well.</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('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/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('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('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> </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('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/2017ClDy...49..163M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ClDy...49..163M"><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>2017-07-01</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/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/2016EGUGA..18.6327T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.6327T"><span>Investigating the influence of <span class="hlt">sea</span> <span class="hlt">level</span> oscillations in the Danish Straits on the Baltic <span class="hlt">Sea</span> dynamics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tikhonova, Natalia; Gusev, Anatoly; Diansky, Nikolay; Zakharchuk, Evgeny</p> <p>2016-04-01</p> <p> 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 <span class="hlt">sea</span>, and in the Stockholm area, this harmonic is at the noise <span class="hlt">level</span>. The 40dy and 121dy harmonics have slightly lower amplitudes than the original prescribed signal, but they are almost unchanged while propagating further into the <span class="hlt">sea</span>, 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 <span class="hlt">sea</span>, and spectral density peaks are at the noise <span class="hlt">level</span>. 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 <span class="hlt">Sea</span>, but the Baltic <span class="hlt">Sea</span> configuration may affect the magnitude and propagation extent of these oscillations. Thus, the fluctuations in the North <span class="hlt">Sea</span> and the Danish Straits can significantly contribute to the Baltic <span class="hlt">Sea</span> 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)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRC..120.5490A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRC..120.5490A"><span>The seasonal cycle and variability of <span class="hlt">sea</span> <span class="hlt">level</span> in the 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>Amiruddin, A. M.; Haigh, I. D.; Tsimplis, M. N.; Calafat, F. M.; Dangendorf, S.</p> <p>2015-08-01</p> <p>The spatial and temporal characteristics of the seasonal <span class="hlt">sea</span> <span class="hlt">level</span> cycle in the South China <span class="hlt">Sea</span> (SCS) and its forcing mechanisms are investigated using tide gauge records and satellite altimetry observations along with steric and meteorological data. The coastal mean annual amplitude of the seasonal cycle varies between zero and 24 cm, reaching a maximum between July and January. The maximum mean semiannual amplitude is 7 cm, peaking between March and June. Along the coast, the seasonal cycle accounts for up to 92% of the mean monthly <span class="hlt">sea</span> <span class="hlt">level</span> variability. Atmospheric pressure explains a significant portion of the seasonal cycle with dominant annual signals in the northern SCS, the Gulf of Thailand and the north-western Philippines <span class="hlt">Sea</span>. The wind forcing is dominant on the shelf areas of the SCS and the Gulf of Thailand where a simple barotropic model forced by the local wind shows annual amplitudes of up to 27 cm. In the deep basin of the SCS, the Philippines <span class="hlt">Sea</span> and the shallow Malacca Strait, the steric component is the major contributor with the maximum annual amplitudes reaching 15 cm. Significant variability in the seasonal cycle is found on a year-to-year basis. The annual and semiannual amplitudes vary by up to 63% and 45% of the maximum values, 15 cm and 11 cm, respectively. On average, stepwise regression analysis of contribution of different forcing factors accounts for 66% of the temporal variability of the annual cycle. The zonal wind was found to exert considerable influence in the Malacca Strait.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.6112Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.6112Z"><span>Correlation and coherence analysis between <span class="hlt">sea</span> surface temperature and altimetric <span class="hlt">sea</span> <span class="hlt">level</span> anomaly data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zbylut-Górska, Maria; Kosek, Wiesław; Wnęk, Agnieszka; Młocek, Wojciech; Rutkowska, Agnieszka; Popiński, Waldemar; Niedzielski, Tomasz</p> <p>2016-04-01</p> <p>One of the main causes of the <span class="hlt">sea</span> <span class="hlt">level</span> variations is the steric effect caused by changes of local <span class="hlt">sea</span> surface temperature (SST). To show how the altimetric <span class="hlt">Sea</span> <span class="hlt">Level</span> Anomaly (SLA) data are related to the SST data, correlation coefficients between them as a function of geographic location were computed. The analysis showed a high positive correlation (about 0.7), especially in the Northern and South-Eastern parts of the Pacific Ocean and a large part of the Atlantic Ocean. There is a negative correlation of about 0.5 in the South-East part of Indian Ocean, on the Arafura <span class="hlt">Sea</span> and the Red <span class="hlt">Sea</span>. In addition the time-frequency coherence and semblance functions between the SLA and SST data were calculated using Fourier transform band pass filter. The maps of such coherence and semblance functions in frequency bands corresponding to the annual oscillation and its integer multiplicities were computed. The most imporntat contribution to the correlation coefficient values has the annual oscillation in the SST and SLA data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24739960','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24739960"><span><span class="hlt">Sea-level</span> and deep-<span class="hlt">sea</span>-temperature variability over the past 5.3 million years.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rohling, E J; Foster, G L; Grant, K M; Marino, G; Roberts, A P; Tamisiea, M E; Williams, F</p> <p>2014-04-24</p> <p>Ice volume (and hence <span class="hlt">sea</span> <span class="hlt">level</span>) and deep-<span class="hlt">sea</span> temperature are key measures of global climate change. <span class="hlt">Sea</span> <span class="hlt">level</span> 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-<span class="hlt">sea</span> oxygen isotope (δ(18)O) data that are influenced by processes unrelated to <span class="hlt">sea</span> <span class="hlt">level</span>. For deep-<span class="hlt">sea</span> temperature, only one continuous high-resolution (Mg/Ca-based) record exists, with related <span class="hlt">sea-level</span> estimates, spanning the past 1.5 Myr. Here we present a novel <span class="hlt">sea-level</span> reconstruction, with associated estimates of deep-<span class="hlt">sea</span> temperature, which independently validates the previous 0-1.5 Myr reconstruction and extends it back to 5.3 Myr ago. We find that deep-<span class="hlt">sea</span> temperature and <span class="hlt">sea</span> <span class="hlt">level</span> 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-<span class="hlt">sea</span> temperature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19850027776','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850027776"><span>Comments on the measurements of multiple <span class="hlt">muon</span> phenomena</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sato, T.; Takahashi, T.; Higashi, S.</p> <p>1985-01-01</p> <p>The extensive air showers in the energy around 10 to the 15th power eV include those initiated by astrophysical primary gamma-rays. The observations need a precise measurement on the directions of primary particles. It is one of the methods to measure the directions of high-energy <span class="hlt">muons</span> in air showers. The accuracy in measuring the direction, by calculating the cosmic-ray phenomena in the atmosphere at very high energy was investgated. The results calculated by Monte Carlo method suggest that one may determine the direction of primary cosmic-rays within errors of 10/3 rad in observing <span class="hlt">muons</span> of above 100 GeV at <span class="hlt">sea</span> <span class="hlt">level</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMPP11G..08R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMPP11G..08R"><span>Searching for Eustasy in Pliocene <span class="hlt">Sea-Level</span> Records (Invited)</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.; Hearty, P. J.; O'Leary, M.; Mitrovica, J.; Deconto, R.; Inglis, J. D.; Robinson, M. M.</p> <p>2010-12-01</p> <p>It is widely accepted that greenhouse gas-induced warming over the next few decades to centuries could lead to a rise in <span class="hlt">sea</span> <span class="hlt">level</span> due to melting ice caps. Yet despite the enormous social and economic consequences for society, our ability to predict the likelihood and location of future melting is hampered by an insufficient theoretical and historical understanding of ice sheet behavior in the past. Various lines of evidence suggest that CO2 <span class="hlt">levels</span> in the mid-Pliocene were between 350-450 ppm, similar to today, and it is important that significant effort be made to confirm these estimates, especially in light of policy discussions that seek to determine a “safe” <span class="hlt">level</span> of atmospheric CO2. Likewise, accurate estimates of mid-Pliocene <span class="hlt">sea</span> <span class="hlt">levels</span> are necessary if we are to better constrain Greenland and Antarctic ice sheet stability in a slightly warmer world. Current published estimates of mid-Pliocene <span class="hlt">sea</span> <span class="hlt">level</span> (during times of maximum insolation forcing) range from +5m to >+40m (relative to present) reflecting a huge range of uncertainty in the sensitivity of polar ice sheets, including the East Antarctic Ice Sheet, to a modest global warming. Accurate determination of the maximum mid-Pliocene <span class="hlt">sea</span> <span class="hlt">level</span> rise is needed if climate and ice sheet modelers are to better assess the robustness of models used to predict the effects of anthropogenic global warming. Pliocene ice volume/highstand estimates fall into two classes, those derived from geologic evidence of past high stands and those derived from geochemical proxies of ice-sensitive changes in ocean chemistry. Both methods have significant errors and uncertainties associated with them. Recent multidisciplinary work along the intra-plate continental margin of Roe Plain (~250 x 30 km) on the southern coastline of Western Australia provides additional constraints on <span class="hlt">sea</span> <span class="hlt">level</span> during the mid-Pliocene. Outcroppings of shore-proximal marine deposits are observed at two distinct elevations across the plain, +28 ± 2 m</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMOS31B2007D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMOS31B2007D"><span>Causes of accelerating <span class="hlt">sea</span> <span class="hlt">level</span> on the East Coast of North America: Implications for future <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>Davis, J. L.; Vinogradova, N. T.</p> <p>2016-12-01</p> <p>The tide-gauge record from the North American east coast reveals significant accelerations in <span class="hlt">sea</span> <span class="hlt">level</span> starting in the late 20th century. We analyze the tide-gauge data using a model in which the accelerations are assumed to be zero prior to 1990. The estimated accelerations range from near zero to 0.3 mm yr-2 and exhibit a systematic spatial variability. (See figure, points with error bars.) We model this variability using several processes: ongoing mass change in Greenland and Antarctica as measured by the GRACE satellites; ocean dynamic and steric variability provided by the GECCO2 ocean synthesis; and the inverted barometer effect. We find that the spatial variability of observed <span class="hlt">sea-level</span> acceleration is well modeled by the sum of these processes. (See figure, blue line.) However, to achieve this fit requires estimation of an admittance for the dynamical and steric contribution, possibly due to the coarse resolution of this analysis or to simplifications associated with parameterization of bottom friction in the shallow coastal areas. Although the ocean dynamic and pressure contributions to the acceleration may fluctuation in the future, other studies indicate that the ice-mass component will increase systematically with time. This component of <span class="hlt">sea-level</span> acceleration is 0.1-0.15 mm yr-2, which if it continues is by itself capable of increasing <span class="hlt">sea</span> <span class="hlt">level</span> in a century by 0.5-0.75 m on the east coast of North America.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11017453','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11017453"><span>CPT and lorentz tests with <span class="hlt">muons</span></span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bluhm; Kostelecky; Lane</p> <p>2000-02-07</p> <p>Precision experiments with <span class="hlt">muons</span> are sensitive to Planck-scale CPT and Lorentz violation that is undetectable in other tests. Existing data on the muonium ground-state hyperfine structure and on the <span class="hlt">muon</span> anomalous magnetic moment could be analyzed to provide dimensionless figures of merit for CPT and Lorentz violation at the <span class="hlt">levels</span> of 4x10(-21) and 10(-23).</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> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.7423M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.7423M"><span>Geodetic infrastructure at the Barcelona harbour 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, Juan Jose; Gili, Josep; Lopez, Rogelio; Tapia, Ana; Pros, Francesc; Palau, Vicenc; Perez, Begona</p> <p>2015-04-01</p> <p>The presentation is directed to the description of the actual geodetic infrastructure of Barcelona harbour with three tide gauges of different technologies for <span class="hlt">sea</span> <span class="hlt">level</span> determination and contribution to regional <span class="hlt">sea</span> <span class="hlt">level</span> rise and understanding past and present <span class="hlt">sea</span> <span class="hlt">level</span> rise in the Barcelona harbour. It is intended that the overall system will constitute a CGPS Station of the ESEAS (European <span class="hlt">Sea</span> <span class="hlt">Level</span>) 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, <span class="hlt">sea</span> <span class="hlt">level</span>, 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 <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">levelling</span> has been made several times in the last two years because the tower is founded in reclaimed land and</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://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=barometer&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dbarometer','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19900033471&hterms=barometer&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dbarometer"><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('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/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/2017EaFut...5..304V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EaFut...5..304V"><span>Extreme <span class="hlt">sea</span> <span class="hlt">levels</span> on the rise along Europe's coasts</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vousdoukas, Michalis I.; Mentaschi, Lorenzo; Voukouvalas, Evangelos; Verlaan, Martin; Feyen, Luc</p> <p>2017-03-01</p> <p>Future extreme <span class="hlt">sea</span> <span class="hlt">levels</span> (ESLs) and flood risk along European coasts will be strongly impacted by global warming. Yet, comprehensive projections of ESL that include mean <span class="hlt">sea</span> <span class="hlt">level</span> (MSL), tides, waves, and storm surges do not exist. Here, we show changes in all components of ESLs until 2100 in view of climate change. We find that by the end of this century, the 100-year ESL along Europe's coastlines is on average projected to increase by 57 cm for Representative Concentration Pathways (RCP)4.5 and 81 cm for RCP8.5. The North <span class="hlt">Sea</span> region is projected to face the highest increase in ESLs, amounting to nearly 1 m under RCP8.5 by 2100, followed by the Baltic <span class="hlt">Sea</span> and Atlantic coasts of the UK and Ireland. Relative <span class="hlt">sea</span> <span class="hlt">level</span> rise (RSLR) is shown to be the main driver of the projected rise in ESL, with increasing dominance toward the end of the century and for the high-concentration pathway. Changes in storm surges and waves enhance the effects of RSLR along the majority of northern European coasts, locally with contributions up to 40%. In southern Europe, episodic extreme events tend to stay stable, except along the Portuguese coast and the Gulf of Cadiz where reductions in surge and wave extremes offset RSLR by 20-30%. By the end of this century, 5 million Europeans currently under threat of a 100-year ESL could be annually at risk from coastal flooding under high-end warming. The presented dataset is available through this link: http://data.jrc.ec.europa.eu/collection/LISCOAST.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMOS31A1703R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMOS31A1703R"><span>Implications of <span class="hlt">Sea</span> <span class="hlt">Level</span> Rise on Coastal Flood Hazards</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Roeber, V.; Li, N.; Cheung, K.; Lane, P.; Evans, R. L.; Donnelly, J. P.; Ashton, A. D.</p> <p>2012-12-01</p> <p>Recent global and local projections suggest the <span class="hlt">sea</span> <span class="hlt">level</span> will be on the order of 1 m or higher than the current <span class="hlt">level</span> by the end of the century. Coastal communities and ecosystems in low-lying areas are vulnerable to impacts resulting from hurricane or large swell events in combination with <span class="hlt">sea-level</span> rise. This study presents the implementation and results of an integrated numerical modeling package to delineate coastal inundation due to storm landfalls at future <span class="hlt">sea</span> <span class="hlt">levels</span>. The modeling package utilizes a suite of numerical models to capture both large-scale phenomena in the open ocean and small-scale processes in coastal areas. It contains four components to simulate (1) meteorological conditions, (2) astronomical tides and surge, (3) wave generation, propagation, and nearshore transformation, and (4) surf-zone processes and inundation onto dry land associated with a storm event. Important aspects of this package are the two-way coupling of a spectral wave model and a storm surge model as well as a detailed representation of surf and swash zone dynamics by a higher-order Boussinesq-type wave model. The package was validated with field data from Hurricane Ivan of 2005 on the US Gulf coast and applied to tropical and extratropical storm scenarios respectively at Eglin, Florida and Camp Lejeune, North Carolina. The results show a nonlinear increase of storm surge <span class="hlt">level</span> and nearshore wave energy with a rising <span class="hlt">sea</span> <span class="hlt">level</span>. The exacerbated flood hazard can have major consequences for coastal communities with respect to erosion and damage to infrastructure.</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/2006GeoRL..3314606Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006GeoRL..3314606Z"><span>Annual <span class="hlt">sea</span> <span class="hlt">level</span> amphidromes in the South China <span class="hlt">Sea</span> revealed 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>Zhang, Caiyun; Wang, Bin; Chen, Ge</p> <p>2006-07-01</p> <p>Annual phase-amplitude characteristics of <span class="hlt">sea</span> <span class="hlt">level</span> anomaly (SLA) in the South China <span class="hlt">Sea</span> (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 <span class="hlt">seas</span>. 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.</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('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/2008AGUSM.U31B..01W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUSM.U31B..01W"><span>Implications of Rising <span class="hlt">Sea</span> <span class="hlt">Level</span> on Everglades Restoration</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wanless, H. R.</p> <p>2008-05-01</p> <p>The strong likelihood of a significant rise in <span class="hlt">sea</span> <span class="hlt">level</span> during this century must be incorporated into the design of the Comprehensive Everglades Restoration Plan (CERP) and its execution. With a warming Arctic and increased wind shear in the waters adjacent to Antarctica, accelerated ice melt of both Greenland and Antarctica has begun. With positive feedbacks, this melt appears irreversible on the century scale. Scientists of the Miami-Dade County Climate Change Task Force project that a global rise of <span class="hlt">sea</span> <span class="hlt">level</span> of at least 0.9-1.5 meters (3-5 feet) will occur by the end of the century. This anticipated rise will diminish the value of CERP unless (a) the design thoroughly incorporates a realistic <span class="hlt">sea</span> <span class="hlt">level</span> rise scenario and (b) there is a refocus of CERP's design to optimize water flow for wetland-community peat growth with the purpose of retarding saline encroachment. The goals of Everglades restoration must become (1) to provide an increase in water flowing at a gradually increasing elevation to permit rapid accumulation of robust organic peat beneath the freshwater wetland and (2) to actively manage the coastal mangrove wetland (e.g., aid hurricane recovery) to help it maintain a robust upwards-building peat margin. If this is done, the central and northern Everglades may survive as a healthy wetland habitat and provide fresh groundwater resources well into the next century. Actively building freshwater and mangrove peat and a dependable supply of freshwater are both critical to retarding saline encroachment up the Everglades depression. Without these, a 1.5 meter rise in <span class="hlt">sea</span> <span class="hlt">level</span> could move saline water nearly to Lake Okeechobee. Critical research questions and changes in management need to be addressed for this to succeed. The communities and conditions for optimal freshwater peat buildup must be documented and demonstrated. New management strategies must be designed and maintained to encourage rapid recovery of mangrove forests destroyed by hurricanes</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1917489E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1917489E"><span>Reconciling projections of the Antarctic contribution to <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>Edwards, Tamsin; Holden, Philip; Edwards, Neil; Wernecke, Andreas</p> <p>2017-04-01</p> <p>Two recent studies of the Antarctic contribution to <span class="hlt">sea</span> <span class="hlt">level</span> rise this century had best estimates that differed by an order of magnitude (around 10 cm and 1 m by 2100). The first, Ritz et al. (2015), used a model calibrated with satellite data, giving a 5% probability of exceeding 30cm by 2100 for <span class="hlt">sea</span> <span class="hlt">level</span> rise due to Antarctic instability. The second, DeConto and Pollard (2016), used a model evaluated with reconstructions of palaeo-<span class="hlt">sea</span> <span class="hlt">level</span>. They did not estimate probabilities, but using a simple assumption here about the distribution shape gives up to a 5% chance of Antarctic contribution exceeding 2.3 m this century with total <span class="hlt">sea</span> <span class="hlt">level</span> rise approaching 3 m. If robust, this would have very substantial implications for global adaptation to climate change. How are we to make sense of this apparent inconsistency? How much is down to the data - does the past tell us we will face widespread and rapid Antarctic ice losses in the future? How much is due to the mechanism of rapid ice loss ('cliff failure') proposed in the latter paper, or other parameterisation choices in these low resolution models (GRISLI and PISM, respectively)? How much is due to choices made in the ensemble design and calibration? How do these projections compare with high resolution, grounding line resolving models such as BISICLES? Could we reduce the huge uncertainties in the palaeo-study? Emulation provides a powerful tool for understanding these questions and reconciling the projections. By describing the three numerical ice sheet models with statistical models, we can re-analyse the ensembles and re-do the calibrations under a common statistical framework. This reduces uncertainty in the PISM study because it allows massive sampling of the parameter space, which reduces the sensitivity to reconstructed palaeo-<span class="hlt">sea</span> <span class="hlt">level</span> values and also narrows the probability intervals because the simple assumption about distribution shape above is no longer needed. We present reconciled probabilistic</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/821148','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/821148"><span>CDF Run 2 <span class="hlt">muon</span> system</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>C. M. Ginsburg</p> <p>2004-02-05</p> <p>The CDF <span class="hlt">muon</span> detection system for Run 2 of the Fermilab Tevatron is described. <span class="hlt">Muon</span> stubs are detected for |{eta}| < 1.5, and are matched to tracks in the central drift chamber at trigger <span class="hlt">level</span> 1 for |{eta}| < 1.25. Detectors in the |{eta}| < 1 central region, built for previous runs, have been enhanced to survive the higher rate environment and closer bunch spacing (3.5 {micro}sec to 396 nsec) of Run 2. Azimuthal gaps in the central region have been filled in. New detectors have been added to extend the coverage from |{eta}| < 1 to |{eta}| < 1.5, consisting of four layers of drift chambers covered with matching scintillators for triggering. The <span class="hlt">Level</span> 1 Extremely Fast Tracker supplies matching tracks with measured p{sub T} for the <span class="hlt">muon</span> trigger. The system has been in operation for over 18 months. Operating experience and reconstructed data are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.5303V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.5303V"><span>Detecting the <span class="hlt">sea</span> <span class="hlt">level</span> fingerprint of accelerated Greenland mass loss</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</p> <p>2017-04-01</p> <p>The tide-gauge record from the North American east coast reveals significant accelerations in <span class="hlt">sea</span> <span class="hlt">level</span> starting in the late 20th century. We analyze the tide-gauge data using a model in which the accelerations are assumed to be zero prior to 1990. The estimated accelerations range from near zero to 0.3 mm yr-2 and exhibit a systematic spatial variability. We model this variability using several processes: ongoing mass change in Greenland and Antarctica as measured by the GRACE satellites; ocean dynamic and steric variability provided by the GECCO2 ocean synthesis; and the inverted barometer effect. Because we are using accelerations over several decades, the contribution from glacial isostatic adjustment is negligible, a substantial benefit of this approach. This approach also enables us to estimate admittances for any of these processes. By including an admittance for the Greenland mass loss, we test the hypothesis that the self-attraction and loading <span class="hlt">sea</span> <span class="hlt">level</span> fingerprint associated with accelerated mass loss is real and observable in the <span class="hlt">sea</span> <span class="hlt">level</span> data. An admittance of zero indicates a rejection of this process. Our estimated admittance is 0.75 ± 0.16, a clear positive detection at the <span class="hlt">level</span> of 4-5 standard deviations.</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('https://eric.ed.gov/?q=Ocean&pg=6&id=EJ920579','ERIC'); return false;" href="https://eric.ed.gov/?q=Ocean&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('http://eric.ed.gov/?q=land&pg=3&id=EJ920579','ERIC'); return false;" href="http://eric.ed.gov/?q=land&pg=3&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('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://adsabs.harvard.edu/abs/2017EGUGA..1911021L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1911021L"><span>Is there any hiatus in global mean <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>Luu, Quang-Hung; Tkalich, Pavel; Wu, Qing</p> <p>2017-04-01</p> <p>The existence of global warming hiatus remains a subject of continuous public and academic debates. In this study, we examine the change of <span class="hlt">sea</span> <span class="hlt">level</span> rise rate during the onset of hiatus (1994-2003) by means of statistical estimations. To deduce the trend, we remove natural variability using satellite altimetry data in association with other climatic indices for the period 1993-2015 at regional scales. After major fluctuations related to El Niño-Southern Oscillation, Pacific Decadal Oscillation, and solar radiation are deducted, the revised rate is found to be slightly faster whereas the uncertainty is reduced by half. Corroborating earlier approaches, our results associate the tendency of global mean <span class="hlt">sea</span> <span class="hlt">level</span> rise during the onset with climate variability.</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.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/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.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('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://www.osti.gov/scitech/servlets/purl/1363911','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1363911"><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.osti.gov/scitech">SciTech Connect</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. As a result, 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('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> </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_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><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" 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_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</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="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011EOSTr..92Q.408S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011EOSTr..92Q.408S"><span>Groundwater depletion's contribution to <span class="hlt">sea</span> <span class="hlt">level</span> rise increasing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schultz, Colin</p> <p>2011-11-01</p> <p>Since the turn of the twentieth century, industrial-scale redistribution of water from landlocked aquifers to the ocean has driven up the global average <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span> 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.</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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4632582','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4632582"><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="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Pike, David A.; Roznik, Elizabeth A.; Bell, Ian</p> <p>2015-01-01</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. PMID:26587269</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/2014AGUFMIN41B3656J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMIN41B3656J"><span>The Future of GLOSS <span class="hlt">Sea</span> <span class="hlt">Level</span> Data Archaeology</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jevrejeva, S.; Bradshaw, E.; Tamisiea, M. E.; Aarup, T.</p> <p>2014-12-01</p> <p>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 <span class="hlt">Sea</span> <span class="hlt">Level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span> data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5434477','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5434477"><span>High <span class="hlt">level</span> of North <span class="hlt">Sea</span> activity should stay</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kemp, A.G. )</p> <p>1991-12-01</p> <p>This paper reports that this next year will see development activity in the UK sector of the North <span class="hlt">Sea</span> remain on a lofty plane. In fact, the value of expenditures could increase significantly above 1991 <span class="hlt">levels</span> and reach {Brit pounds}4.5 billion ($7.83 million). Such massive activity is due to the coincident development of large oil and natural gas fields, among which are Bruce, Miller, Scott, Everest, Lomond and Alba.</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/2011GeoJI.186.1036T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011GeoJI.186.1036T"><span>Ongoing glacial isostatic contributions to observations of <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>Tamisiea, Mark E.</p> <p>2011-09-01</p> <p>Studies determining the contribution of water fluxes to <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span> 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 <span class="hlt">sea</span> <span class="hlt">level</span>' 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 <span class="hlt">sea</span> <span class="hlt">level</span> studies based on gravity data; each study must estimate a bound on the GIA correction consistent with the adopted data-analysis scheme.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6578049','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6578049"><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://www.osti.gov/scitech">SciTech Connect</a></p> <p>Denton, G.H.; Hughes, T.J.; Karlen, W.</p> <p>1986-01-01</p> <p>Denton and Hughes 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 later 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/sup 0/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. But factors other than areal changes of the grounded Antarctic Ice Sheet may have 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, but another potential influence was high-frequency climatic oscillations. 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 /sup 14/C yr B.P. This permitted renewed formation of North Atlantic Deep Water, which could well have controlled atmospheric carbon dioxide. Combined melting and consequent <span class="hlt">sea-level</span> rise from the three warming factors initiated irreversible collapse of the interlocked global ice-sheet system, which was at its largest but most vulnerable configuration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu