These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

Weather Variability, Tides, and Barmah Forest Virus Disease in the Gladstone Region, Australia  

PubMed Central

In this study we examined the impact of weather variability and tides on the transmission of Barmah Forest virus (BFV) disease and developed a weather-based forecasting model for BFV disease in the Gladstone region, Australia. We used seasonal autoregressive integrated moving-average (SARIMA) models to determine the contribution of weather variables to BFV transmission after the time-series data of response and explanatory variables were made stationary through seasonal differencing. We obtained data on the monthly counts of BFV cases, weather variables (e.g., mean minimum and maximum temperature, total rainfall, and mean relative humidity), high and low tides, and the population size in the Gladstone region between January 1992 and December 2001 from the Queensland Department of Health, Australian Bureau of Meteorology, Queensland Department of Transport, and Australian Bureau of Statistics, respectively. The SARIMA model shows that the 5-month moving average of minimum temperature (? = 0.15, p-value < 0.001) was statistically significantly and positively associated with BFV disease, whereas high tide in the current month (? = ?1.03, p-value = 0.04) was statistically significantly and inversely associated with it. However, no significant association was found for other variables. These results may be applied to forecast the occurrence of BFV disease and to use public health resources in BFV control and prevention. PMID:16675420

Naish, Suchithra; Hu, Wenbiao; Nicholls, Neville; Mackenzie, John S.; McMichael, Anthony J.; Dale, Pat; Tong, Shilu

2006-01-01

2

Tides and Decadal Variability  

NASA Technical Reports Server (NTRS)

This paper reviews the mechanisms by which oceanic tides and decadal variability in the oceans are connected. We distinguish between variability caused by tides and variability observed in the tides themselves. Both effects have been detected at some level. The most obvious connection with decadal timescales is through the 18.6-year precession of the moon's orbit plane. This precession gives rise to a small tide of the same period and to 18.6-year modulations in the phase and amplitudes of short-period tides. The 18.6-year "node tide" is very small, no more than 2 cm anywhere, and in sea level data it is dominated by the ocean's natural Variability. Some authors have naively attributed climate variations with periods near 19 years directly to the node tide, but the amplitude of the tide is too small for this mechanism to be operative. The more likely explanation (Loder and Garrett, JGR, 83, 1967-70, 1978) is that the 18.6-y modulations in short-period tides, especially h e principal tide M2, cause variations in ocean mixing, which is then observed in temperature and other climatic indicators. Tidally forced variability has also been proposed by some authors, either in response to occasional (and highly predictable) tidal extremes or as a nonlinear low-frequency oscillation caused by interactions between short-period tides. The former mechanism can produce only short-duration events hardly more significant than normal tidal ranges, but the latter mechanism can in principle induce low-frequency oscillations. The most recent proposal of this type is by Keeling and Whorf, who highlight the 1800-year spectral peak discovered by Bond et al. (1997). But the proposal appears contrived and should be considered, in the words of Munk et al. (2002), "as the most likely among unlikely candidates."

Ray, Richard D.

2003-01-01

3

Lunar tide contribution to thermosphere weather  

NASA Astrophysics Data System (ADS)

As the utilization of low-Earth orbit increases, so does the need for improved ephemeris predictions and thus more accurate density models. In this paper we quantify the density variability of the thermosphere attributable to the lunar gravitational tide, a potentially predictable component of variability not included in any operational density prediction models to date. Using accelerometer measurements from the GOCE satellite near 260 km altitude, the level of lunar tidal density variability is shown to be about half that associated with the low level of geomagnetic variability that occurs about 75% of the time (Kp ? 3), thus constituting an element of "space weather." Our conclusion is that the lunar tide ought to be considered for inclusion in contemporary density models of the thermosphere for operational ephemeris predictions. Some suggested first steps are included in the conclusions of this paper.

Zhang, Jesse T.; Forbes, Jeffrey M.; Zhang, Casey H.; Doornbos, Eelco; Bruinsma, Sean L.

2014-08-01

4

Weather sends red tide packing  

NSDL National Science Digital Library

This Mobile Register newspaper article provides general information about the impact of a cold front on red tide in Alabama. Red tide in the area had been rising until the front passed through, killing most of the phytoplankton bloom.

Finch, Bill; Register, Mobile

5

Intraseasonal variability and tides in Makassar Strait  

NASA Astrophysics Data System (ADS)

Intraseasonal variability and tides along the Makassar Strait, the major route of Indonesian throughflow, are investigated using spectral and time-frequency analyses which are applied to sea level, wind and mooring data. Semidiurnal and diurnal tides are dominant features, with higher (lower) semidiurnal (diurnal) energy in the north compared to the south. Sea levels and mooring data display intraseasonal variability which are probably a response to remotely forced Kelvin waves from the Indian Ocean through Lombok Strait and to Rossby waves from the Pacific Ocean. Sea levels in Tarakan and Balikpapan and Makassar mooring velocities reveal intraseasonal features with periods of 48-62 days associated with Rossby waves from the Sulawesi Sea. Kelvin wave features with periods of 67-100 days are seen in Bali (Lombok Strait), at the mooring sites and in Balikpapan, however, they are not seen in Tarakan, which implies that these waves diminish after passing through the Makassar Strait.

Susanto, R. Dwi; Gordon, Arnold L.; Sprintall, Janet; Herunadi, Bambang

6

Interannual and Intraseasonal Variability of the Diurnal Tide  

NASA Astrophysics Data System (ADS)

Temporal variations in the amplitude of the diurnal tide (DT) have been observed by radars with a seasonal dependence that is typically semiannual in the tropics. During some years the wind variation departs from the normal seasonal behavior with anomalously large amplitudes compared to most other years. This anomaly often takes the form of a greatly enhanced boreal spring equinoctal maximum. The boreal spring of 2008 is a example of this behavior. Diurnal amplitudes in the meridional winds are shown in the figure below for the first 6 months of 2008. Note that the diurnal tide undergoes a sharp increase in amplitude up to 80 ms-1 during this event. The characteristics of this event are diagnosed in a variety of global data sets. These include our own physics-based assimilation of SABER temperatures, and gridded analyses from the national weather services (NCAR/NCEP and ECMWF). Tidal amplitude variations are sometimes attributed to nonlinear interaction. However, this type of interaction would be expected to produce non-migrating tides, e.g., westward-2 or standing. SABER data show that the amplitude anomaly is mainly in the migrating DT. The global data sets allow us to explore properties of the anomaly, such as its origin, evolution in time, and associated momentum flux. In addition to this case study, we also investigate the general characteristics of DT interannual variability during the years of the SABER mission (2002-present). Diurnal tide momentum deposition plays a significant role in controlling the zonal mean wind in the mesosphere, We demonstrate its importance in driving the mesospheric semiannual oscillation (MSAO). Diurnal tide wind amplitudes in the meridional component observed at two radar sites, Rarotonga, Cook Islands (22.1°S, 159.8°W), and at Guanacaste, Costa Rica (10.3°N, 85.6°W).

Riggin, D. M.; Ortland, D. A.; Lieberman, R. S.; Oberheide, J.; Murayama, Y.; Hocking, W. K.; Vincent, R. A.; Reid, I. M.; Kumar, G. K.; Batista, P. P.; Clemesha, B. R.

2013-12-01

7

Solar Variability, Weather, and Climate  

Microsoft Academic Search

Solar Variability, Weather, and Climate reassesses the question of solar variability and its effects on weather and climate, taking into account new measurements and more recent theories of the earth's atmosphere. The papers, which make up this book, were presented at an American Geophysical Union meeting in December 1978. Besides a review of the current basic knowledge on the topic,

A. Berger

1983-01-01

8

Solar variability, weather, and climate  

NASA Technical Reports Server (NTRS)

Advances in the understanding of possible effects of solar variations on weather and climate are most likely to emerge by addressing the subject in terms of fundamental physical principles of atmospheric sciences and solar-terrestrial physis. The limits of variability of solar inputs to the atmosphere and the depth in the atmosphere to which these variations have significant effects are determined.

1982-01-01

9

Tides  

NSDL National Science Digital Library

This data tip from Bridge, the Ocean Sciences Education Teacher Resource Center archive, focuses on tides. Students learn how to plan for tide-affected activities by using the NOAA Tide Predictions page to calculate tidal predictions for several days at a site of interest in the coastal United States. Students are also linked to a site with global data where they may generate a graph of tidal predictions for a location near them. Several other educational sites are referenced.

2000-08-01

10

High-tide flight by wintering Dunlins (Calidris alpina): a weather-dependent trade-off between energy loss and predation risk  

E-print Network

Falcons (Falco peregrinus Tunstall, 1771), which captured 81 prey in 494 attacks. The maximum kill rate: Dunlins, Calidris alpina, high-tide flight, weather dependence, Peregrine Falcon, Falco peregrinus variables étaient chassés par des faucons pèlerins (Falco peregrinus Tunstall, 1771), qui ont capturé 81

11

Understanding the variability of an extreme storm tide along a coastline  

NASA Astrophysics Data System (ADS)

Correctly determining the peak storm tide height along the coastline, and expressing the associated natural variability, is essential for a robust prediction of coastal flood risk. A new approach is proposed that calculates a storm tide relationship (relative to a tide gauge) by using a storm surge model to describe the natural spatial variability based on the features of a large number of very high storm tides. Two historic flood events (1953 and 2007) were used to validate this characteristics approach along the East Anglia coastline (U.K.), and predicted water-levels were found to be in good agreement with tide gauge observations (Root Mean Squared Error of 36 cm), especially when compared to the method of assuming a storm tide of constant return period (Root Mean Squared Error of 59 cm). Detailed observations of storm tide height between tide gauge locations are rare; therefore, Synthetic Aperture Radar (SAR) was employed to calculate the LiDAR geo-referenced storm tide height along the North Somerset coastline of the Bristol Channel (U.K.). Two SAR observed "extreme" storm tide events were used to validate the characteristics approach between tide gauges (Root Mean Squared Error of 1.2 m and 0.7 m), and indicated the presence of localised wave effects to the observed storm tide height that could have a significant effect to flood risk estimates.

Lewis, M.; Schumann, G.; Bates, P.; Horsburgh, K.

2013-05-01

12

Effects of weather and tides on feeding and flock positions of wintering redheads in the Chandeleur Sound, Louisiana  

Microsoft Academic Search

We studied the effects of weather and tides on percent feeding and flock positions of wintering redheads (Aythya americana Eyton) in the Chandeleur Sound, Louisiana, USA. Flock scans (n = 750) were made on 55 flocks from November through March of 1988–1989. The percent of the flock that was feeding was negatively correlated with time of day, temperature, water level,

Thomas C. Michot; E. Barry Moser; Wayne Norling

1994-01-01

13

Weather variability, climatic change, and grain production.  

PubMed

A cooling trend in the world's climate would have serious effects in the monsoon belts depending on whether or not the recent changes in snow and ice cover in the polar regions were responsible for the droughts in Africa and the failure of the monsoons over South Asia. The cooling and shrinking of the atmosphere at the higher latitudes is believed to have brought the subtropical anticyclones nearer to the tropical rainbelt and have caused a shifting of the monsoon belt. The regions that would be most severely affected by a continuation of the cooling trend to the year 2000 would be the higher latitudes (above 50 degrees) where spring wheat is grown and the warm band below 30 degrees latitude where rice is the principal grain crop. Weather variability is a much more important consideration in grain production than a cooling trend. Our highest yields are made when weather is near normal or slightly cooler than normal. It is when weather variables deviate greatly from normal that yields are lowest. Even if the weather does trend toward the coolness of a century ago yields will not be reduced significantly unless the weather becomes more varible. PMID:17740005

Thompson, L M

1975-05-01

14

Assessing the temporal variability in extreme storm-tide time series for coastal flood risk assessment  

NASA Astrophysics Data System (ADS)

probability of extreme storm-tide events has been extensively studied; however, the variability within the duration of such events and implications to flood risk is less well understood. This research quantifies such variability during extreme storm-tide events (the combined elevation of the tide, surge, and their interactions) at 44 national tide gauges around the UK. Extreme storm-tide events were sampled from water level measurements taken every 15 min between 1993 and 2012. At each site, the variability in elevation at each time step, relative to a given event peak, was quantified. The magnitude of this time series variability was influenced both by gauge location (and hence the tidal and nontidal residual characteristics) and the time relative to high water. The potential influence of this variability on coastal inundation was assessed across all UK gauge sites, followed by a detailed case study of Portsmouth. A two-dimensional hydrodynamic model of the Portsmouth region was used to demonstrate that given a current 1 in 200 year storm-tide event, the predicted number of buildings inundated differed by more than 30% when contrasting simulations forced with the upper and lower bounds of the observed time series variability. The results indicate that variability in the time series of the storm-tide event can have considerable influence upon overflow volumes, hence with implications for coastal flood risk assessments. Therefore, further evaluating and representing this uncertainty in future flood risk assessments is vital, while the envelopes of variability defined in this research provides a valuable tool for coastal flood modelers.

Quinn, N.; Lewis, M.; Wadey, M. P.; Haigh, I. D.

2014-08-01

15

Barometric Tides from ECMWF Operational Analyses  

NASA Technical Reports Server (NTRS)

The solar diurnal and semidiurnal tidal oscillations in surface pressure are extracted from the the operational analysis product of the European Centre for Medium Range Weather Forecasting (ECMWF). For the semidiurnal tide this involves a special temporal interpolation, following Van den Dool and colleagues. The resulting tides are compared with a ground truth tide dataset, a compilation of well-determined tide estimates deduced from long time series of station barometer measurements. These comparisons show that the ECMWF tides are significantly more accurate than the tides deduced from two other widely available reanalysis products. Spectral analysis of ECMWF pressure series shows that the tides consist of sharp central peaks with modulating sidelines at integer multiples of 1 cycle/year, superimposed on a broad cusp of stochastic energy. The integrated energy in the cusp dominates that of the sidelines. This complicates development of a simple model that can characterize the full temporal variability of the tides.

Ray, R. D.; Ponte, R. M.

2003-01-01

16

Variability of diurnal tides and planetary waves during November 1978-May 1979  

NASA Astrophysics Data System (ADS)

Nonlinear interactions between stationary waves and the migrating tides have been proposed as possible sources of nonmigrating tides in the middle and upper atmosphere. The objective of this study is to increase observational support for these processes. We examine the evolution of stationary planetary waves and nonmigrating diurnal tides in the lower mesosphere during November 1978-May 1979, based on a newly released, version 6 of the Nimbus 7 LIMS dataset. Planetary wavenumber one is large and variable during the Northern hemisphere winter months, reaching peak amplitude in the lower mesosphere between 20 and 30 January. This behavior is accompanied by rapid amplification of nonmigrating diurnal tides with zonal wavenumbers zero and two. These components correspond to product waves generated by interaction between the migrating diurnal tide and the stationary wave. The westward traveling zonal wavenumber two diurnal tide is dominant at tropical latitudes, in accordance with theoretical studies. The correlation between the nonmigrating tide and stationary wavenumber one is highest when the stationary wave penetrates to subtropical latitudes.

Lieberman, R. S.; Oberheide, J.; Hagan, M. E.; Remsberg, E. E.; Gordley, L. L.

2004-04-01

17

On the Temporal Variability of Low-Mode Internal Tides in the Deep Ocean  

NASA Technical Reports Server (NTRS)

In situ measurements of internal tides are typically characterized by high temporal variability, with strong dependence on stratification, mesoscale eddies, and background currents commonly observed. Thus, it is surprising to find phase-locked internal tides detectable by satellite altimetry. An important question is how much tidal variability is missed by altimetry. We address this question in several ways. We subset the altimetry by season and find only very small changes -- an important exception being internal tides in the South China Sea where we observe strong seasonal dependence. A wavenumber-domain analysis confirms that throughout most of the global ocean there is little temporal variability in altimetric internal-tide signals, at least in the first baroclinic mode, which is the mode that dominates surface elevation. The analysis shows higher order modes to be significantly more variable. The results of this study have important practical implications for the anticipated SWOT wide-swath altimeter mission, for which removal of internal tide signals is critical for observing non-tidal submesoscale phenomena.

Ray, Richard D.; Zaron, E. D.

2010-01-01

18

A Link between Variability of the Semidiurnal Tide and Planetary Waves in the Opposite Hemisphere  

NASA Technical Reports Server (NTRS)

Horizontal wind observations over four years from the meteor radar at Esrange (68 deg N) are analyzed to determine the variability of the semidiurnal tide. Simultaneous global observations of temperature and geopotential from the SABER satellite instrument are used to construct time series of planetary wave amplitudes and geostrophic mean zonal wind. During NH summer and fall, the temporal variability of the semidiurnal tide at Esrange is found to be well correlated with the amplitude of planetary wavenumber 1 in the stratosphere in high southern latitudes (i.e., in the opposite hemisphere). The correlations indicate that a significant part of the tidal variations at Esrange is due to dynamical interactions in the Southern Hemisphere. Other times of the year do not indicate a corresponding robust correlation pattern for the Esrange tides over multiple years.

Smith, Anne K.; Pancheva, Dora V.; Mitchell, Nicholas J.; Marsh, Daniel R.; Russell, James M., III; Mlynczak, Martin G.

2007-01-01

19

Atmospheric tides forced by troposphere heating: Longitudinal variability of upper atmosphere consequences  

NASA Astrophysics Data System (ADS)

This PhD work is motivated by the unprecedented observations provided by the SABER (Sounding of the Atmosphere using Broadband Emission Radiometry) instrument on the TIMED (Thermosphere Ionosphere Mesosphere Energetics and Dynamics) spacecraft. Through creative methods that avoid aliasing problems between tidal variations and mean background temporal variations, a fairly clear picture of both migrating and nonmigrating solar thermal tides from the stratosphere to the MLT (Mesosphere and Lower Thermosphere) region is obtained. The background structures in zonal mean temperatures, geopotential, and the zonal mean gradient zonal winds are also achieved. By retrieving net radiative heating rate profiles from the most updated solar radiative fluxes provided by ISCCP/NASA-GISS (International Satellite Cloud Climatology Project/NASA Goddard Institute for Space Studies) and constructing latent heating rate profiles from the most recent TRMM/NASA-GSFC (Tropical Rainfall Measuring Mission/NASA Goddard Space Flight Center) daily latent heating profiles and 3-hourly TRMM rainfall rates, total tropospheric tidal heating rate profiles are obtained. The Global Scale Wave Model (GSWM) is thus updated with the new tropospheric heat sources and observed mean background inputs to result in the latest version of GSWM, GSWM-09. By comparing GSWM-09 and SABER tidal signatures, the importance of troposphere heat energy in driving atmospheric tides in the MLT region is confirmed and the relative importance of radiative and latent heat sources for migrating and nonmigrating tides is demonstrated with emphasis on longitudinal variability of MLT tides. It confirms that the eastward-propagating diurnal tide with zonal wave number 3 is the outstanding nonmigrating tide due to the topography-modulated tropospheric heating. The critical factors for the seasonal-latitudinal variations of DE3 are examined based on classical tidal theory and its modern developments, since these variations are much improved in GSWM-09, taking observed SABER tidal signatures as the reference. It demonstrates that both mean zonal wind and tropospheric heating are critical in determining the seasonal-latitudional variations of DE3.

Zhang, Xiaoli

20

The influence of atmospheric tide and planetary wave variability during sudden stratosphere warmings on the low latitude ionosphere  

NASA Astrophysics Data System (ADS)

Numerical simulations are performed for a sudden stratosphere warming (SSW) under different atmospheric tide and planetary wave forcing conditions to investigate the tidal variability in the mesosphere and lower thermosphere (MLT). The influence of variability of different tides in the MLT on generating perturbations to the low latitude ionosphere is also investigated. Significant changes are found to occur in the migrating semidiurnal solar (SW2) and lunar (M2) tides as well as in the westward propagating nonmigrating semidiurnal tide with zonal wave number 1 (SW1). The changes in the zonal mean atmosphere that occur during SSWs lead to an enhancement in the SW2 and M2 tides. The vertical wavelength of the SW2 is also changed, resulting in phase variability in the SW2 at a constant altitude. Significant enhancements in the SW1 are found to occur only in the presence of additional planetary wave forcing, and this demonstrates that nonlinear planetary wave?tide interactions lead to the enhanced SW1 during SSWs. The amplitude and phase variability of the SW2 is found to be capable of producing temporal variability in the vertical plasma drift velocity that is similar to the observed variability. Changes in the M2 during SSWs can contribute up to an additional ˜30% of the total ionosphere variability; however, the overall influence of the lunar tide is found to be dependent upon the phase of the moon relative to the timing of the SSW. Although the influence is relatively minor, the SW1 also contributes to the low latitude ionosphere variability during SSWs. The simulation results for the vertical plasma drift velocity and total electron content (TEC) further illustrate that significant longitude variability occurs in the ionosphere response to SSWs.

Pedatella, N. M.; Liu, H.-L.

2013-08-01

21

Impact of the winter North-Atlantic weather regimes on subtropical sea-surface height variability  

NASA Astrophysics Data System (ADS)

Interannual variability of subtropical sea-surface-height (SSH) anomalies, estimated by satellite and tide-gauge data, is investigated in relation to wintertime daily North-Atlantic weather regimes. Sea-level anomalies can be viewed as proxies for the subtropical gyre intensity because of the intrinsic baroclinic structure of the circulation. Our results show that the strongest correlation between SSH and weather regimes is found with the so-called Atlantic-Ridge (AR) while no significant values are obtained for the other regimes, including those related to the North Atlantic Oscillation (NAO), known as the primary actor of the Atlantic dynamics. Wintertime AR events are characterized by anticyclonic wind anomalies off Europe leading to a northward shift of the climatological wind-stress curl. The latter affects subtropical SSH annual variability by altered Sverdrup balance and ocean Rossby wave dynamics propagating westward from the African coast towards the Caribbean. The use of a simple linear planetary geostrophic model allows to quantify those effects and confirms the primary importance of the winter season to explain the largest part of SSH interannual variability in the Atlantic subtropical gyre. Our results open new perspectives in the comprehension of North-Atlantic Ocean variability emphasizing the role of AR as a driver of interannual variability at least of comparable importance to NAO.

Barrier, Nicolas; Treguier, Anne-Marie; Cassou, Christophe; Deshayes, Julie

2013-09-01

22

A new interpretation of Mars aerobraking variability: Planetary wave-tide interactions  

NASA Astrophysics Data System (ADS)

This study presents a new interpretation of Mars aerobraking density observations in terms of planetary wave-tide interactions. Mars Global Surveyor and Mars Reconnaissance Orbiter provide invaluable information about tidal activity in the lower thermosphere of Mars through the longitude structure that they reveal in near-Sun-synchronous frame of reference. However, this same perspective does not permit one to uncover the origins of day-to-day variability of these structures. Herein, by employing a new arrangement of the data and understanding the relationship between spectral features in longitude space versus UT space, we are able to attribute a significant amount of density variability in the aerobraking region to the effect of tidal modulation by planetary waves in the 5-20 day period range.

Moudden, Y.; Forbes, J. M.

2010-09-01

23

Understanding Space Weather: The Sun as a Variable Star  

NASA Technical Reports Server (NTRS)

The Sun is a complex system of systems and until recently, less than half of its surface was observable at any given time and then only from afar. New observational techniques and modeling capabilities are giving us a fresh perspective of the solar interior and how our Sun works as a variable star. This revolution in solar observations and modeling provides us with the exciting prospect of being able to use a vastly increased stream of solar data taken simultaneously from several different vantage points to produce more reliable and prompt space weather forecasts. Solar variations that cause identifiable space weather effects do not happen only on solar-cycle timescales from decades to centuries; there are also many shorter-term events that have their own unique space weather effects and a different set of challenges to understand and predict, such as flares, coronal mass ejections, and solar wind variations

Strong, Keith; Saba, Julia; Kucera, Therese

2011-01-01

24

Understanding Space Weather: The Sun as a Variable Star  

NASA Technical Reports Server (NTRS)

The Sun is a complex system of systems and until recently, less than half of its surface was observable at any given time and then only from afar. New observational techniques and modeling capabilities are giving us a fresh perspective of the solar interior and how our Sun works as a variable star. This revolution in solar observations and modeling provides us with the exciting prospect of being able to use a vastly increased stream of solar data taken simultaneously from several different vantage points to produce more reliable and prompt space weather forecasts. Solar variations that cause identifiable space weather effects do not happen only on solar-cycle timescales from decades to centuries; there are also many shorter-term events that have their own unique space weather effects and a different set of challenges to understand and predict, such as flares, coronal mass ejections, and solar wind variations.

Strong, Keith; Saba, Julia; Kucera, Therese

2012-01-01

25

Spatial differences in thermal structure and variability within a small bay: Interplay of diurnal winds and tides  

NASA Astrophysics Data System (ADS)

We characterize diurnal and semidiurnal temporal variability of the spring and summer near-shore hydrographic structure and circulation in Cartagena Bay, a small open bay in central Chile, and assess the relative role of diurnal wind and semidiurnal tide as forcing mechanisms of that variability. Our results highlight that the relative importance of these forcing mechanisms and the thermal structure can vary over small spatial scales within the bay. The water column at the southern and most wind-sheltered study site within the Bay (CTGN) was stratified all day despite the sea breeze. Throughout the water column, temperature variability at CTGN was strongly associated with the semidiurnal tide. At the northern site (ECIM), which was relatively more exposed to wind forcing, surface layer temperature fluctuations were principally diurnal and tightly associated with diurnal wind variability. The wind effect weakened near the bottom, where temperature variability was also correlated with the semidiurnal tide. At ECIM, we observed a vertically sheared cross-shore current structure, with onshore surface flow and offshore flow at mid-depth during strong winds. The diurnal variability in cross-shore flows matched diurnal variability in winds, suggesting that this vertical circulation could be directly forced by the wind. The diurnal circulation and the spatial differences in thermal structure across the bay are likely to be important for larval dispersal and material transport in and out of the Bay, as well as between near-shore waters and the shoreline.

Bonicelli, Jessica; Moffat, Carlos; Navarrete, Sergio A.; Largier, John L.; Tapia, Fabian J.

2014-10-01

26

Sea-level variability in tide-gauge and geological records: An empirical Bayesian analysis (Invited)  

NASA Astrophysics Data System (ADS)

Sea level varies at a range of temporal and spatial scales, and understanding all its significant sources of variability is crucial to building sea-level rise projections relevant to local decision-making. In the twentieth-century record, sites along the U.S. east coast have exhibited typical year-to-year variability of several centimeters. A faster-than-global increase in sea-level rise in the northeastern United States since about 1990 has led some to hypothesize a 'sea-level rise hot spot' in this region, perhaps driven by a trend in the Atlantic Meridional Overturning Circulation related to anthropogenic climate change [1]. However, such hypotheses must be evaluated in the context of natural variability, as revealed by observational and paleo-records. Bayesian and empirical Bayesian statistical approaches are well suited for assimilating data from diverse sources, such as tide-gauges and peats, with differing data availability and uncertainties, and for identifying regionally covarying patterns within these data. We present empirical Bayesian analyses of twentieth-century tide gauge data [2]. We find that the mid-Atlantic region of the United States has experienced a clear acceleration of sea level relative to the global average since about 1990, but this acceleration does not appear to be unprecedented in the twentieth-century record. The rate and extent of this acceleration instead appears comparable to an acceleration observed in the 1930s and 1940s. Both during the earlier episode of acceleration and today, the effect appears to be significantly positively correlated with the Atlantic Multidecadal Oscillation and likely negatively correlated with the North Atlantic Oscillation [2]. The Holocene and Common Era database of geological sea-level rise proxies [3,4] may allow these relationships to be assessed beyond the span of the direct observational record. At a global scale, similar approaches can be employed to look for the spatial fingerprints of land ice melt [5]. We end by presenting preliminary results from such an analysis. [1] Sallenger et al. (2012), Nat. Clim. Change 2: 884-888. [2] Kopp (in press),Geophys. Res. Lett. [3] Engelhart and Horton (2011), Quat. Sci. Rev. 54: 12-25. [4] Kemp et al. (2011), Proc. Natl. Acad. Sci. 108: 11017-11022. [5] Hay et al. (2013). Proc. Natl. Acad. Sci. 110: 3692-3699.

Kopp, R. E.; Hay, C.; Morrow, E.; Mitrovica, J. X.; Horton, B.; Kemp, A.

2013-12-01

27

Ocean tides  

Microsoft Academic Search

According to their spatial scales and to the generation mechanisms applying, tidal phenomena in the sea are presented together with hydrodynamic models explaining their existence and appearance. The astronomical tide generating forces, to which the tidal variations of the ocean state variables can finally be traced, have planetary scale and therefore can directly excite tidal oscillations in the open ocean.

Wilfried Zahel

1997-01-01

28

Initialisation of Land Surface Variables for Numerical Weather Prediction  

NASA Astrophysics Data System (ADS)

Land surface processes and their initialisation are of crucial importance for Numerical Weather Prediction (NWP). Current land data assimilation systems used to initialise NWP models include snow depth analysis, soil moisture analysis, soil temperature and snow temperature analysis. This paper gives a review of different approaches used in NWP to initialise land surface variables. It discusses the observation availability and quality, and it addresses the combined use of conventional observations and satellite data. Based on results from the European Centre for Medium-Range Weather Forecasts (ECMWF), results from different soil moisture and snow depth data assimilation schemes are shown. Both surface fields and low-level atmospheric variables are highly sensitive to the soil moisture and snow initialisation methods. Recent developments of ECMWF in soil moisture and snow data assimilation improved surface and atmospheric forecast performance.

de Rosnay, Patricia; Balsamo, Gianpaolo; Albergel, Clément; Muñoz-Sabater, Joaquín; Isaksen, Lars

2014-05-01

29

Temporal variability of global Topex\\/Poseidon altimetry: tide and annual signals?  

Microsoft Academic Search

Summary  The global power of the differences of altimetric sea heights at collocated points in the first 44 cycles of the Topex\\/Poseidon\\u000a (T\\/P) mission, apparently shows the influence of errors in the major tides and long period ocean signals. Results show the\\u000a principal semidiurnal tides (M2\\/S2 lumped together) in the Cartwright and Ray (1991) model are probably in error globally\\u000a by

C. A. Wagner; C. K. Tai; J. M. Kuhn

1995-01-01

30

Quantifying storm tide risk in Fiji due to climate variability and change  

NASA Astrophysics Data System (ADS)

Extreme sea level events due to tropical cyclone storm surge combined with astronomical tide (storm tides) severely impact Pacific Island communities and these impacts are expected to increase with projected sea level rise. However, these sea level extremes are not well characterised by available tide gauge records owing to the low frequency of occurrence of tropical cyclones, the sparse array of tide gauges and the short time frame over which many gauges in this region have been operating. In this study, a combined statistical/dynamical method for estimating storm tide risk is presented. Tropical cyclones in the Fiji region over the period 1969-2007 are characterised in a statistical model that represents cyclone frequency, intensity and movement. The statistical model is then used to develop a population of “synthetic” cyclones that provide boundary conditions to a hydrodynamic storm surge and tidal model. This Monte-Carlo method is applied to the coasts of the Fiji archipelago. It is found that storm tide risk is higher on the northwest coasts of both the southern and northern main islands Viti Levu and Vanua Levu, respectively. Modelling suggests that there is a greater tendency for higher storm surges to occur on southwest Viti Levu under El Niño and La Niña years compared with average years, but elsewhere on Viti Levu and Vanua Levu, there is a tendency for slightly lower storm surges in La Niña years. Imposing perturbations to the cyclone statistical model that represent projected tropical cyclone changes in intensity and frequency for mid to late 21st Century, leads to storm tide return period curves that are steeper such that sea levels associated with return periods of 200 years or more become higher, those with return periods of 50 years and less become lower and the 1-in-100 year heights are little changed. Projected changes in sea level are found to make the largest contribution to increased extreme sea level risk.

McInnes, Kathleen L.; Walsh, Kevin J. E.; Hoeke, Ron K.; O'Grady, Julian G.; Colberg, Frank; Hubbert, Graeme D.

2014-05-01

31

A WINTERING FLOCK OF GOLDEN PLOVERS'Pluviaiis'apricaria iN RELATION TO TiDE AND WEATHER  

Microsoft Academic Search

and at times Golden Plover. We decided to make daily accounts of the Plover from November 1977 through to March 1978, noting which areas they used and whether they were feeding or resting, to see if this correlated with environmental factors such as temperature, tide or wind. Since the Dunbar meteorological station lies within the study area such data was

Rennie Weatherhead

32

Red Tide  

NSDL National Science Digital Library

This CDC web page includes links to PDF or html formatted files containing information about Karenia brevis, a phytoplankton responsible for toxic red tide events. Links include information about red tide, what the CDC is doing about red tide, links to other red tide related sites, and publications about red tide.

Control, U. S.

33

Weather  

NSDL National Science Digital Library

This is a first grade weather unit. SEASONS Fall Winter Build a Snowman Spring Summer What things determine and effect the weather? Cloud Precipitation Sunshine Temperature Visibility Wind Direction Wind Force WEATHER VIDEOS Tornado Hurricane Hail Lightning FUN AND GAMES Dress the Bear for the Weather The Great Weather Race Game Weather coloring books for kids ...

Stearns, Ms.

2008-10-25

34

Weather  

NSDL National Science Digital Library

This lesson is written for fourth grade students. Students will explore weather and the effects it has on their lives. What is weather? video of what is weather Let's take a walk through the weather. Put on your hats and coats! Clouds Cloud Types Clouds - Dan's Wild Weather Page What to Wear? What to Wear? What to Drink? Weather Patterns and Climatic Regions ...

Bullough, Ms.

2010-06-24

35

Space Weather Products from the Extreme Ultraviolet Variability Experiment (EVE)  

NASA Astrophysics Data System (ADS)

A majority of the solar flare energy is released in the hard x-ray (HXR), soft x-ray (SXR), and extreme ultraviolet (EUV) ranges, and thus these wavelengths are an important measure of solar activity for myriad of space weather applications and operations. The EUV Variability Experiment (EVE) aboard NASA's Solar Dynamics Observatory (SDO) is observing the solar SXR and EUV irradiance continuously from its GEO orbit with 10 sec and better cadence and with spectral resolution of 0.1 nm over most of the EUV range (6-105 nm). EVE's space weather data products are near realtime with latency less than a minute. While EVE Level 1-3 products are intended to be research quality, the quicklook Level 0C and 0CS products are appropriate for space weather operations. For example, the EVE Level 0CS product includes EVE's EUV SpectroPhometer (ESP) measurement of the 1-7 nm band irradiance that is used as a backup proxy for the GOES X-ray Sensor (XRS) 0.1-0.8 nm flare monitor. The ESP and also EVE's Solar Aspect Monitor (SAM) x-ray imager also provide realtime knowledge of the flare location. The EVE Level 0C product includes EVE's Multiple EUV Grating Spectrographs (MEGS) spectra and a listing of the brighter lines. Of particular interest for this session, the cooler coronal emission lines, e.g. Fe IX - Fe XII in the 17-20 nm range, often have coronal dimming during and after a flare, and the slope and depth of the dimming may be indicative of a coronal mass ejection (CME) velocity and mass. If so, then EVE's realtime monitor of these cooler coronal emissions could become a useful proxy for CME warnings.

Woods, T. N.; Woodraska, D.; Jones, A. R.; Eparvier, F. G.; Caspi, A.

2012-12-01

36

Weather  

NSDL National Science Digital Library

Have you ever wondered how the weather man, or meteorolgist, on TV knows what to say about tomorrow\\'s weather? It\\'s because they have certain tools that they use that help them predict what the weather will be. Throughout this school year you are going to be making tools and predicting weather just like a meterorologist! Task You are going to be weather forcasters! You are going to record and track weather patterns throughout the year. You will also use weather tools to make predictions about the weather like real weather forecasters! The Process 1. First we need to learn a little bit about weather so ...

Williams, Ms.

2005-10-25

37

Congruent responses to weather variability in high arctic herbivores.  

PubMed

Assessing the role of weather in the dynamics of wildlife populations is a pressing task in the face of rapid environmental change. Rodents and ruminants are abundant herbivore species in most Arctic ecosystems, many of which are experiencing particularly rapid climate change. Their different life-history characteristics, with the exception of their trophic position, suggest that they should show different responses to environmental variation. Here we show that the only mammalian herbivores on the Arctic islands of Svalbard, reindeer (Rangifer tarandus) and sibling voles (Microtus levis), exhibit strong synchrony in population parameters. This synchrony is due to rain-on-snow events that cause ground ice and demonstrates that climate impacts can be similarly integrated and expressed in species with highly contrasting life histories. The finding suggests that responses of wildlife populations to climate variability and change might be more consistent in Polar regions than elsewhere owing to the strength of the climate impact and the simplicity of the ecosystem. PMID:23015455

Stien, Audun; Ims, Rolf A; Albon, Steve D; Fuglei, Eva; Irvine, R Justin; Ropstad, Erik; Halvorsen, Odd; Langvatn, Rolf; Loe, Leif Egil; Veiberg, Vebjørn; Yoccoz, Nigel G

2012-12-23

38

Two-layer tidal modeling of the Yellow and East China Seas with application to seasonal variability of the M2 tide  

Microsoft Academic Search

The baroclinic response of tide and tidal currents in the Yellow and East China Seas is investigated using a two-layer numerical model. Seasonal variability in the M2 tide, especially the smaller summer amplitudes prevailing along the Korea\\/Tsushima Strait [Kang et al., 1995], is investigated by a series of numerical experiments with varying degrees of stratification specific to winter and summer.

Sok Kuh Kang; Michael G. G. Foreman; Heung-Jae Lie; Jae-Hak Lee; Josef Cherniawsky; Ki-Dai Yum

2002-01-01

39

A new interpretation of Mars aerobraking variability: Planetary wave-tide interactions  

Microsoft Academic Search

This study presents a new interpretation of Mars aerobraking density observations in terms of planetary wave-tide interactions. Mars Global Surveyor and Mars Reconnaissance Orbiter provide invaluable information about tidal activity in the lower thermosphere of Mars through the longitude structure that they reveal in near-Sun-synchronous frame of reference. However, this same perspective does not permit one to uncover the origins

Y. Moudden; J. M. Forbes

2010-01-01

40

Entropy Shows that Global Warming Should Cause Increased Variability in the Weather  

E-print Network

Elementary physical reasoning seems to leave it inevitable that global warming would increase the variability of the weather. The first two terms in an approximation to the global entropy are used to show that global warming has increased the free energy available to drive the weather, and that the variance of the weather should increase correspondingly.

John Michael Williams

2000-08-28

41

Weathering  

NSDL National Science Digital Library

This course handout covers the processes and effects of weathering. The purpose of this handout is to contrast weathering and erosion, contrast and discuss chemical and mechanical weathering, list the products resulting from the chemical weathering of igneous rocks, and list and discuss the factors that influence the type and rate of rock weathering. Many photographs accompany this summary which depict weathered landscapes. Links are provided to the online Physical Geology resources at Georgia Perimeter College.

Gore, Pamela

1995-08-29

42

Ocean tides  

NASA Technical Reports Server (NTRS)

A review of recent developments in the study of ocean tides and related phenomena is presented. Topics briefly discussed include: the mechanism by which tidal dissipation occurs; continental shelf, marginal sea, and baroclinic tides; estimation of the amount of energy stored in the tide; the distribution of energy over the ocean; the resonant frequencies and Q factors of oceanic normal modes; the relationship of earth tides and ocean tides; and numerical global tidal models.

Hendershott, M. C.

1975-01-01

43

Weather.  

ERIC Educational Resources Information Center

This theme issue of "The Goldfinch" focuses on weather in Iowa and weather lore. The bulletin contains historical articles, fiction, activities, and maps. The table of contents lists: (1) "Wild Rosie's Map"; (2) "History Mystery"; (3) "Iowa's Weather History"; (4) "Weather Wonders"; (6) "Seasonal Jobs"; (7) "Fiction: Winter Courage"; (8) "Stayin'…

Ruth, Amy, Ed.

1996-01-01

44

Weather Radar and Hydrology 1 Influence of rainfall spatial variability on hydrological modelling: a  

E-print Network

Weather Radar and Hydrology 1 Influence of rainfall spatial variability on hydrological modelling variability as well as characteristics and hydrological behavior of catchments, we have proceeded simulator and a distributed hydrological model (with four production functions and a distributed transfer

Paris-Sud XI, Université de

45

Global structure and seasonal variability of the migrating terdiurnal tide in the mesosphere and lower thermosphere  

NASA Astrophysics Data System (ADS)

The morphology of the migrating terdiurnal tide with zonal wavenumber 3 (TW3) in the mesosphere and lower thermosphere (MLT) is revealed using the TIMED satellite datasets from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) and the TIMED Doppler Interferometer (TIDI) instruments from 2002 to 2009, as well as the Thermosphere Ionosphere Mesosphere Electrodynamics General Circulation Model (TIME-GCM). The annual mean structures of the TW3 from the TIME-GCM clearly resemble the first real symmetric (3,3) Hough mode. The TW3 temperature and zonal wind components have three peaks at midlatitudes and near the equator, while the TW3 meridional wind components show four peaks at mid and low latitudes. These features are consistent with those resolved in SABER temperature and TIDI zonal wind above ~95 km. TW3 components in the TIME-GCM are stronger during winter and spring months at midlatitudes, which is in agreement with previous ground-based radar measurements. On the other hand, TW3 components of temperature, zonal and meridional winds from SABER and TIDI display different seasonal variations at different altitudes and latitudes. The results presented in this paper will provide an observational basis for further modeling study of terdiurnal tide impacts on the thermosphere and ionosphere.

Yue, Jia; Xu, Jiyao; Chang, Loren C.; Wu, Qian; Liu, Han-Li; Lu, Xian; Russell, James

2013-12-01

46

Weather  

NSDL National Science Digital Library

Introduction: How much do you know about weather? What kinds of weather do we have surrounding us? What is the weather like today? You may know a lot about weather already, you may not. Either way, you will learn more now as we take a look into what causes our weather and the methods we use to record and predict it. We will all become meteorologists, which are scientists who study the atmosphere and can predict weather. Put on your raincoats, and lets started! Task: You are the resident meteorologist at a local news station. It is your job to record and predict the weather each day, and then present it that night on the evening news. Not only should you be able to show the weather that we will be experiencing right ...

Hendricks, Ms.

2007-12-06

47

Mahogany Tides  

NSDL National Science Digital Library

This Smithsonian K-12 Education website provides a brief overview of mahogany tide (also known as red tide) events. These events are caused by dinoflagellates, a special type of phytoplankton, and can harm sea life. This website also features links to other related red tide sites.

Education, Smithsonian

48

Weather  

NSDL National Science Digital Library

What are the different types of weather? In this project you will compare different types of weather by drawing pictures and making it into a flip book. First you will begin by learning about the different types of weather. Read about each topic. Then get together with your partner and draw a picture of each type of weather. 1. Thunder storm Thunder storm Thunder storm Kids 2. Lightning Lightning Lightning picture 3. Tornado Tornadoes Tornado Kids 4. ...

Jennie, Miss

2009-10-22

49

ASSESSMENT OF THE POTENTIAL EFFECTS OF CLIMATE CHANGE AND CLIMATE VARIABILITY ON WEATHER-RELATED MORBIDITY  

EPA Science Inventory

The potential effects of climate change and climate variability on weather-related morbidity are assessed. Heat-related and cold-related morbidity in children are analyzed. The impact of inclement weather on accidental injuries is evaluated. The relationship of violent crime to w...

50

King Tide floods in Tuvalu  

NASA Astrophysics Data System (ADS)

The spatial and temporal distributions of sea level rise present regional floods in some certain areas. The low-lying island countries are obviously the spots affected severely. Tuvalu, an atoll island country located in the south-west Pacific Ocean, is suffering the devastating effects of losing life, property, and intending migration caused by floods. They blame the regional flooding to King Tide, a term used but not clearly identified by Pacific islanders. In this study, we clarify what King Tide is first. By the tide gauge and topography data, we estimated the reasonable value of 3.2 m as the threshold of King Tide. This definition also fits to the statement by National Oceanic and Atmospheric Administration (NOAA) of King Tide occurring once or twice a year. In addition, We cross validate the 19 yr data of tide gauge and satellite altimeter (1993-2012), the correlation coefficient indicates King Tide phenomenon is considerable connected to warm water mass. The 28 King Tide events revealed the fact that flooding can be referenced against spring tide levels, so can it be turned up by warm water mass. The warm water mass pushes up sea level; once spring tide, storm surge, or other climate variability overlaps it, the rising sea level might overflow and so has been called "King Tide" for the floods in Tuvalu. This study provides more understanding of the signals of King Tide and an island country case study of regional sea level rise.

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

2013-05-01

51

Spatial and temporal variability of tide-induced salt flux in a partially mixed estuary  

E-print Network

Mechanisms for the tidal component of salt flux in the Hudson River estuary are investigated using a 3D numerical model. Variations with river discharge, fortnightly tidal forcing, and along channel variability are explored. ...

Engel, Patricia Ann

2009-01-01

52

On the occurrence and variability of the terdiurnal tide in the equatorial mesosphere and lower thermosphere and a comparison with the Kyushu-GCM  

NASA Astrophysics Data System (ADS)

We studied the occurrence characteristics and variability of the terdiurnal tide (8 hour period) in the equatorial mesosphere and lower thermosphere (MLT), using a meteor radar at Koto Tabang (0.2°S, 100.3°E) and MF radars at Tirunelveli (8.7°N, 77.8°E) and Pameungpeuk (7.4°S, 107.4°E). These locations, one being located right over the equator and the other two at conjugate points around the equator within ±10°, form a unique experimental setup to study equatorial MLT dynamics. The terdiurnal tide exists as a distinct wave signature at all three locations. While the daily amplitudes can be as large as 15 m s-1, the monthly mean amplitudes lie between 1 and 10 m s-1. The amplitude of the terdiurnal tide at Pameungpeuk is generally smaller than that observed at Tirunelveli and Koto Tabang. The seasonal variation in amplitude shows both annual and semiannual oscillations of ˜1 m s-1 at all three locations. The present observations combined with previous reports indicate that the timing of the primary maximum of the terdiurnal tide amplitude shifts from autumn to late spring and early summer as one moves from high latitudes to the equator (all with respect to the Northern Hemisphere). The amplitudes and seasonal variation in the present observations show good comparison with that simulated by the General Circulation Model (GCM) developed by Kyushu University, Japan. This study supports the occurrence of nonlinear interaction between diurnal and semidiurnal tides and shows that gravity waves play an important role in the generation of the terdiurnal tide.

Venkateswara Rao, N.; Tsuda, T.; Gurubaran, S.; Miyoshi, Y.; Fujiwara, H.

2011-01-01

53

Weathering  

NSDL National Science Digital Library

This interactive Flash resource provides information regarding physical and chemical weathering at an introductory physical geology or Earth science level. It includes animations, diagrams, and supplementary information and is suitable for high school or undergraduate students.

Smoothstone; Mifflin, Houghton

54

Red Tides  

NSDL National Science Digital Library

This comprehensive website answers questions such as: what is red tide, where are they found, why do they occur, how do they affect marine organisms, how do they affect humans, how are shellfish tested for the toxin, and what is being done to remediate the red tide problem. The site features color pictures and black and white maps.

Communications Directorate, Department O.

55

A Bayesian hierarchical model with spatial variable selection: the effect of weather on insurance claims  

PubMed Central

Climate change will affect the insurance industry. We develop a Bayesian hierarchical statistical approach to explain and predict insurance losses due to weather events at a local geographic scale. The number of weather-related insurance claims is modelled by combining generalized linear models with spatially smoothed variable selection. Using Gibbs sampling and reversible jump Markov chain Monte Carlo methods, this model is fitted on daily weather and insurance data from each of the 319 municipalities which constitute southern and central Norway for the period 1997–2006. Precise out-of-sample predictions validate the model. Our results show interesting regional patterns in the effect of different weather covariates. In addition to being useful for insurance pricing, our model can be used for short-term predictions based on weather forecasts and for long-term predictions based on downscaled climate models. PMID:23396890

Scheel, Ida; Ferkingstad, Egil; Frigessi, Arnoldo; Haug, Ola; Hinnerichsen, Mikkel; Meze-Hausken, Elisabeth

2013-01-01

56

Meteogram: A Day's Weather Variables, Hour by Hour, on the Same Page  

NSDL National Science Digital Library

This activity is designed to teach students how to read and understand a meteogram. It should enable students to more readily understand the movements of fronts and the interactions of weather variables as illustrated by the meteogram. Generally students measure and observe the variables as separate entities but by viewing the weather variables including temperature, dew point, wind speed, wind direction, precipitation, cloud cover, atmospheric pressure, cloud elevation, maximum and minimum temperatures simultaneously hour by hour, the interrelationships are more evident. The site includes suggested questions and links to helpful sites.

Rauch, Arden

57

Daily weather variables and affective disorder admissions to psychiatric hospitals  

NASA Astrophysics Data System (ADS)

Numerous studies have reported that admission rates in patients with affective disorders are subject to seasonal variation. Notwithstanding, there has been limited evaluation of the degree to which changeable daily meteorological patterns influence affective disorder admission rates. A handful of small studies have alluded to a potential link between psychiatric admission rates and meteorological variables such as environmental temperature (heat waves in particular), wind direction and sunshine. We used the Kruskal-Wallis test, ARIMA and time-series regression analyses to examine whether daily meteorological variables—namely wind speed and direction, barometric pressure, rainfall, hours of sunshine, sunlight radiation and temperature—influence admission rates for mania and depression across 12 regions in Ireland over a 31-year period. Although we found some very weak but interesting trends for barometric pressure in relation to mania admissions, daily meteorological patterns did not appear to affect hospital admissions overall for mania or depression. Our results do not support the small number of papers to date that suggest a link between daily meteorological variables and affective disorder admissions. Further study is needed.

McWilliams, Stephen; Kinsella, Anthony; O'Callaghan, Eadbhard

2014-03-01

58

Daily weather variables and affective disorder admissions to psychiatric hospitals.  

PubMed

Numerous studies have reported that admission rates in patients with affective disorders are subject to seasonal variation. Notwithstanding, there has been limited evaluation of the degree to which changeable daily meteorological patterns influence affective disorder admission rates. A handful of small studies have alluded to a potential link between psychiatric admission rates and meteorological variables such as environmental temperature (heat waves in particular), wind direction and sunshine. We used the Kruskal-Wallis test, ARIMA and time-series regression analyses to examine whether daily meteorological variables-namely wind speed and direction, barometric pressure, rainfall, hours of sunshine, sunlight radiation and temperature-influence admission rates for mania and depression across 12 regions in Ireland over a 31-year period. Although we found some very weak but interesting trends for barometric pressure in relation to mania admissions, daily meteorological patterns did not appear to affect hospital admissions overall for mania or depression. Our results do not support the small number of papers to date that suggest a link between daily meteorological variables and affective disorder admissions. Further study is needed. PMID:24599495

McWilliams, Stephen; Kinsella, Anthony; O'Callaghan, Eadbhard

2014-12-01

59

A k-nearest-neighbor simulator for daily precipitation and other weather variables  

NASA Astrophysics Data System (ADS)

A multivariate, nonparametric time series simulation method is provided to generate random sequences of daily weather variables that "honor" the statistical properties of the historical data of the same weather variables at the site. A vector of weather variables (solar radiation, maximum temperature, minimum temperature, average dew point temperature, average wind speed, and precipitation) on a day of interest is resampled from the historical data by conditioning on the vector of the same variables (feature vector) on the preceding day. The resampling is done from the k nearest neighbors in state space of the feature vector using a weight function. This approach is equivalent to a nonparametric approximation of a multivariate, lag 1 Markov process. It does not require prior assumptions as to the form of the joint probability density function of the variables. An application of the resampling scheme with 30 years of daily weather data at Salt Lake City, Utah, is provided. Results are compared with those from the application of a multivariate autoregressive model similar to that of Richardson [1981].

Rajagopalan, Balaji; Lall, Upmanu

1999-10-01

60

"Weather" Variability Of Close-in Extrasolar Giant Planets  

E-print Network

Shallow-water numerical simulations show that the atmospheric circulation of the close-in extrasolar giant planet (EGP) HD 209458b is characterized by moving circumpolar vortices and few bands/jets (in contrast with ~10 bands/jets and absence of polar vortices on cloud-top Jupiter and Saturn). The large spatial scales of moving circulation structures on HD 209458b may generate detectable variability of the planet's atmospheric signatures. In this Letter, we generalize these results to other close-in EGPs, by noting that shallow-water dynamics is essentially specified by the values of the Rossby (Ro) and Burger (Bu) dimensionless numbers. The range of likely values of Ro (~ 0.01 - 10) and Bu (~ 1 - 200) for the atmospheric flow of known close-in EGPs indicates that their circulation should be qualitatively similar to that of HD 209458b. This results mostly from the slow rotation of these tidally-synchronized planets.

Kristen Menou; James Y-K. Cho; Sara Seager; Brad Hansen

2002-10-22

61

A knearest-neighbor simulator for daily precipitation and other weather variables  

E-print Network

A k­nearest-neighbor simulator for daily precipitation and other weather variables Balaji wind speed, and precipitation) on a day of interest is resampled from the historical data. This approach is equivalent to a nonparametric approximation of a multivariate, lag 1 Markov process. It does

Balaji, Rajagopalan

62

Development of a variable speed limit strategy to reduce secondary collision risks during inclement weathers.  

PubMed

Inclement weather reduces traveler's sight distance and increases vehicle's stopping distance. Once a collision occurred during inclement weather and resulted in a slow traffic, approaching vehicles may not have adequate time to make emergency responses to the hazardous traffic, resulting in increased potentials of secondary collisions. The primary objective of this study is to develop a control strategy of variable speed limits (VSL) to reduce the risks of secondary collisions during inclement weathers. By analyzing the occurrence condition of secondary collision, the VSL strategy is proposed to dynamically adjust the speed limits according to the current traffic and weather conditions. A car-following model is modified to simulate the vehicle maneuvers with the VSL control. Two surrogate safety measures, based on the time-to-collision notion, are used to evaluate the control effects of VSL. Five weather scenarios are evaluated in simulation. The results show that the VSL strategy effectively reduces the risks of secondary collisions in various weather types. The time exposed time-to-collision (TET) is reduced by 41.45%-50.74%, and the time integrated time-to-collision (TIT) is reduced by 38.19%-41.19%. The safety effects are compared to those with a previous VSL strategy. The results show that in most cases our strategy outperforms the previous one. We also evaluate how driver's compliance to speed limit affects the effectiveness of VSL control. PMID:25035970

Li, Zhibin; Li, Ye; Liu, Pan; Wang, Wei; Xu, Chengcheng

2014-11-01

63

Toxic Tide  

NSDL National Science Digital Library

This website provides access to a news article published in September 2005 by the Sarasota Herald-Tribune in which Mote Marine researchers responded to a series of questions posed by the Herald-Tribune editorial board about red tides. The article discusses a historical bloom event that occurred on Florida's Gulf Coast in 2005. The article also provides information about the causative organism, Karenia brevis, as well as about the general occurrence of red tides in this region, health effects, and the environmental factors that trigger a bloom event.

Mahadevan, Kumar; Pierce, Richard; Kirkpatrick, Barbara; Kirkpatrick, Gary; Dixon, L. K.; Herald-Tribune, Sarasota

64

Kingdom of the Tides.  

ERIC Educational Resources Information Center

Areas of discussion are the history of tides, the forces which exert an influence upon the earth's tides, the behavior of tides as modified by terrestrial features, "freak" behavior of tides, the marine life which inhabits tidal areas, the manner in which tides have helped to shape the course of history, how tides affect our lives on a day to day…

Carter, Samuel, III

65

What weather variables are important in predicting heat-related mortality? A new application of statistical learning methods.  

PubMed

Hot weather increases risk of mortality. Previous studies used different sets of weather variables to characterize heat stress, resulting in variation in heat-mortality associations depending on the metric used. We employed a statistical learning method - random forests - to examine which of the various weather variables had the greatest impact on heat-related mortality. We compiled a summertime daily weather and mortality counts dataset from four U.S. cities (Chicago, IL; Detroit, MI; Philadelphia, PA; and Phoenix, AZ) from 1998 to 2006. A variety of weather variables were ranked in predicting deviation from typical daily all-cause and cause-specific death counts. Ranks of weather variables varied with city and health outcome. Apparent temperature appeared to be the most important predictor of heat-related mortality for all-cause mortality. Absolute humidity was, on average, most frequently selected as one of the top variables for all-cause mortality and seven cause-specific mortality categories. Our analysis affirms that apparent temperature is a reasonable variable for activating heat alerts and warnings, which are commonly based on predictions of total mortality in next few days. Additionally, absolute humidity should be included in future heat-health studies. Finally, random forests can be used to guide the choice of weather variables in heat epidemiology studies. PMID:24834832

Zhang, Kai; Li, Yun; Schwartz, Joel D; O'Neill, Marie S

2014-07-01

66

Virtual Tide Pool  

NSDL National Science Digital Library

Virtual Tide Pool features a three dimensional view of a tide pool during both low and high tides. Students can see animals that live under, above, and at the waters surface. This site offers the ability to pan the tide pool for a 360 degree view, with zoom options, and gives descriptions of the animals found during both low and high tides.

Science NetLinks (PBS;)

2003-04-29

67

Tide-related variability of TAG hydrothermal activity observed by deep-sea monitoring system and OBSH  

NASA Astrophysics Data System (ADS)

Hydrothermal activities were monitored by an ocean bottom seismometer with hydrophone (OBSH) and a composite measuring system (Manatee) including CTD, current meter, transmission meter and cameras at a small depression on the TAG hydrothermal mound in the Mid-Atlantic Ridge. Low-frequency pressure pulses detected by the hydrophone with semi-diurnal periodicity seem to correspond to cycles of hydrothermal upflow from a small and short-lived smoker vent close to the observing site. The peaks of pressure pulses are synchronous with the maximum gradient of areal strain decrease due to tidal load release. Microearthquakes with very near epicenters occur sporadically and do not appear to be directly correlatable to hydrothermal venting. Temporal variations in bottom water temperature also have semi-diurnal periodicity but are more complicated than the pressure events. Temperatures may be affected both by upwelling of hot water and by lateral flow of the bottom current changing its directions with ocean tide.

Fujioka, Kantaro; Kobayashi, Kazuo; Kato, Kazuhiro; Aoki, Misumi; Mitsuzawa, Kyohiko; Kinoshita, Masataka; Nishizawa, Azusa

1997-12-01

68

Tides and gravity labs  

NSDL National Science Digital Library

How does gravity cause tides in the oceans? This section, part of an interactive laboratory series for grades 8-12, introduces students to four activities on tides and gravity that cover critical orbital speed between Earth and the moon, gravitational forces between two bodies, tidal effects from the sun and moon, and the change in tidal levels over time. The activities include hands-on animations of concepts whose variables can be manipulated by students. Questions posed to students include answer boxes that are printable upon conclusion of the activities. The final activity involves collecting tidal data over 24-hour and 29-day periods. Student data are stored in printable tables. Views of moon phases for each time period are provided, as is a downloadable worksheet. Copyright 2005 Eisenhower National Clearinghouse

University of Utah. Astrophysics Science Project Integrating Research and Education (ASPIRE)

2002-01-01

69

Mechanism for the effects of variable solar activity on the weather. Final report  

SciTech Connect

The goal of the research was to help in identifying the most likely physical mechanisms for the effects of variable solar activity on the weather. The method of attack was largely empirical, and this method was chosen for the following reasons: (1) in order to tap the great pool of scientific talent that may be able to offer sound physical mechanisms, it is necessary to demonstrate that there are some important relationships to explain; and (2) if the experiments are carefully designed, they can be useful in eliminating certain mechanisms which seem to have a low probability of success, and picking out the mechanisms which look more promising. Some results are presented.

None

1981-01-01

70

Circulation weather types and spatial variability of daily precipitation in the Iberian Peninsula %K circulation weather types, daily gridded precipitation, Iberian Peninsula, spatial variability, seasonal variability  

NASA Astrophysics Data System (ADS)

The relationships between atmospheric circulation patterns and daily Iberian rainfall are here explored at high spatial resolution (0.2°) using the Jenkinson and Collison automated classification scheme with 26 Weather Types (WTs). The WTs were computed by means of the daily EMULATE Mean Sea Level Pressure dataset (EMSLP) while the high resolution precipitation database corresponds to the recent Iberia02 daily gridded precipitation dataset over the 1950-2003 period. Six monthly indexes relating the WTs and precipitation were analyzed: their Frequency, the Mean Precipitation, the Percentage Contribution, the Area of Influence, the Precipitation Intensity and Efficiency. Except for the Frequency of the WTs, all other indexes were evaluated studying their spatial distribution over the Iberian Peninsula, focusing on a WT and a month at time. A small number of WTs (7) was found to capture a high percentage (~70%) of monthly Iberian precipitation. The Westerly WT is the most influent one, followed by the Cyclonic, the Northwesterly and the Southwesterly WTs. Westerly flows, however, do not affect the Mediterranean fringe or the Cantabrian coast, which are dominated by the Easterly and Northerly WTs, respectively. Rainfall along the Mediterranean coastline and the Ebro basin depends on a variety of WTs, but their effects are confined to narrow areas and short temporal intervals, suggesting that local factors such as convective processes, orography and the proximity to a warm water body could play a major role in precipitation processes. We show that the use of daily gridded precipitation dataset holds the advantage of measuring the daily rainfall amount due to each WT directly instead to relying on the predicted values of the regression model as done in previous works.

Ramos, Alexandre; Cortesi, Nicola; Trigo, Ricardo

2014-10-01

71

Influence of seasonal weather and climate variability on crop yields in Scotland.  

PubMed

The climatic sensitivity of four important agriculture crops (wheat, barley, oats, potatoes) in a northern temperate bioclimatic region is investigated using national-level yield data for 1963-2005. The climate variables include monthly and annual meteorological data, derived bioclimatic metrics, and the North Atlantic Oscillation index. Statistical analysis shows that significant relationships between yield and climate vary depending on the crop type and month but highlight the influence of precipitation (negative correlation) and sunshine duration (positive correlation) rather than temperature. Soil moisture deficit is shown to be a particular useful indicator of yield with drier summers providing the best yields for Scotland as a whole. It is also tentatively inferred that the sensitivity of these crops, particularly wheat and barley, to soil moisture deficits has increased in recent years. This suggests that improved crop yields are optimised for dry sunny years despite the continued prevalence of considerable inter-annual variability in seasonal weather. PMID:22960748

Brown, Iain

2013-07-01

72

New Jersey Tide Telemetry System  

USGS Publications Warehouse

Each summer the population of the barrier-island communities of New Jersey increases by tens of thousands. When a coastal storm threatens these communities, the limited number of bridges and causeways that connect the islands with the mainland become overcrowded, making evacuations from the barrier islands to the mainland difficult. Timely evacuation depends on well-defined emergency evacuation plans used in conjunction with accurate flood forecasting and up to the minute (real-time) tide-level information. The 'Great Nor'easter' storm that struck the coastal areas of New Jersey on December 11, 1992, caused about $270 million in insured damages to public and private property (Dorr and others, 1995). Most of the damage was due to tidal flooding and storm surge, which were especially severe along the back bay areas. Comprehensive and reliable tide-level and meteorological data for the back bays was needed to make accurate flood forecasts. Collection of tidal data for the ocean and large bays was adequately covered by the National Oceanic and Atmospheric Administration's National Ocean Service (NOAA's NOS), but in New Jersey little to no data are available for the back-bay areas. The back bays behave quite differently than the ocean as a result of the complex interaction between the winds and the geometry of the inlets and bays. A slow moving Nor'easter can keep tide levels in back bays several feet higher than the ocean tide by not allowing tides to recede, resulting in flooding of bridges and causeways that link the barrier islands to the mainland. The U.S. Geological Survey (USGS), in cooperation with the New Jersey Department of Transportation (NJDOT), designed and installed the New Jersey Tide Telemetry System (NJTTS) with assistance from NOAA's NOS in 1997. This system is part of a statewide network of tide gages, weather stations, and stream gages that collect data in real time. The NJTTS supplies comprehensive, reliable real-time tide-level and meteorological data for flood-prone areas along the New Jersey shore and back bays. These data are transmitted to computer base stations located at offices of the National Weather Service, New Jersey State Police (NJSP), NJDOT, county emergency management agencies, other critical decision-making centers, and the World Wide Web (WWW). This fact sheet describes the NJTTS and identifies its benefits.

Hoppe, Heidi L.

2007-01-01

73

Influence of synoptic weather patterns on solar irradiance variability in Europe  

NASA Astrophysics Data System (ADS)

Solar radiation is important for many aspects of existence on Earth, including the biosphere, the hydrological cycle, and creatures living on the planet. Previous studies have reported decadal trends in observational records of surface shortwave (SW) irradiance around the world, too strong to be caused by varying solar output. These observed decadal trends have been dubbed "solar dimming and brightening" and are believed to be related to changes in atmospheric aerosols and cloud cover. Because the observed solar variability coincides with qualitative air pollution histories, the dimming and brightening have become almost synonymous with shortwave attenuation by anthropogenic aerosols. However, there are indications that atmospheric circulation patterns have influenced the dimming and brightening in some regions, e.g., Alaska and Scandinavia. In this work, we focus on the role of atmospheric circulation patterns in modifying shortwave irradiance. An examination of European SW irradiance data from the Global Energy Balance Archive (GEBA) shows that while there are periods of predominantly decreasing (~1970-1985) and increasing (~1985-2007) SW irradiance, the changes are not spatially uniform within Europe and in a majority of locations not statistically significant. To establish a connection between weather patterns and sunshine, regression models of SW irradiance are fitted using a daily classification of European weather called Grosswetterlagen (GWL). The GWL reconstructions of shortwave irradiance represent the part of the solar variability that is related to large scale weather patterns, which should be effectively separated from the influence of varying anthropogenic aerosol emissions. The correlation (R) between observed and reconstruced SW irradiance is between 0.31 and 0.75, depending on station and season, all statistically significant (p<0.05, estimated with a bootstrap test). In central and eastern parts of Europe, the observed decadal SW variability is poorly represented by the GWL models, but in northern Europe, the GWL model recreates observed decadal solar variability well. This finding suggests that natural and/or anthropogenic variations in circulation patterns have influenced solar dimming and brightening to a higher degree in the north than in the rest of Europe.

Parding, Kajsa; Hinkelman, Laura; Liepert, Beate; Ackerman, Thomas; Dagestad, Knut-Frode; Asle Olseth, Jan

2014-05-01

74

Weather and Forecasting Fine-Scale Orographic Precipitation Variability and Gap-Filling Radar Potential in Little  

E-print Network

Weather and Forecasting Fine-Scale Orographic Precipitation Variability and Gap-Filling Radar Title: Fine-Scale Orographic Precipitation Variability and Gap-Filling Radar Potential in Little and forecasting of precipitation in LCC using a gap-filling radar. Powered by Editorial Manager® and Produ

Steenburgh, Jim

75

Relative Roles of Weather Variables and Change in Human Population in Malaria: Comparison over Different States of India  

PubMed Central

Background Pro-active and effective control as well as quantitative assessment of impact of climate change on malaria requires identification of the major drivers of the epidemic. Malaria depends on vector abundance which, in turn, depends on a combination of weather variables. However, there remain several gaps in our understanding and assessment of malaria in a changing climate. Most of the studies have considered weekly or even monthly mean values of weather variables, while the malaria vector is sensitive to daily variations. Secondly, rarely all the relevant meteorological variables have been considered together. An important question is the relative roles of weather variables (vector abundance) and change in host (human) population, in the change in disease load. Method We consider the 28 states of India, characterized by diverse climatic zones and changing population as well as complex variability in malaria, as a natural test bed. An annual vector load for each of the 28 states is defined based on the number of vector genesis days computed using daily values of temperature, rainfall and humidity from NCEP daily Reanalysis; a prediction of potential malaria load is defined by taking into consideration changes in the human population and compared with the reported number of malaria cases. Results For most states, the number of malaria cases is very well correlated with the vector load calculated with the combined conditions of daily values of temperature, rainfall and humidity; no single weather variable has any significant association with the observed disease prevalence. Conclusion The association between vector-load and daily values of weather variables is robust and holds for different climatic regions (states of India). Thus use of all the three weather variables provides a reliable means of pro-active and efficient vector sanitation and control as well as assessment of impact of climate change on malaria. PMID:24971510

Goswami, Prashant; Murty, Upadhayula Suryanarayana; Mutheneni, Srinivasa Rao; Krishnan, Swathi Trithala

2014-01-01

76

Influence of Weather Variables and Plant Communities on Grasshopper Density in the Southern Pampas, Argentina  

PubMed Central

A study was conducted to evaluate the influence of weather (precipitation and temperature) and plant communities on grasshopper density over a 14-year period (1996–2009) in Benito Juárez County, Southern Pampas, Argentina. Total density strongly varied among plant communities. Highest values were registered in 2001 and 2003 in highly disturbed pastures and in 2002 and 2009 in halophilous grasslands. Native grasslands had the lowest density values. Seasonal precipitation and temperature had no significant effect on total grasshopper density. Dichroplus elongatus (Giglio-Tos) (Orthoptera: Acridoidea), Covasacris pallidinota (Bruner), Dichroplus pratensis Bruner, Scotussa lemniscata Stål, Borellia bruneri (Rehn) and Dichroplus maculipennis (Blanchard) comprised, on average, 64% of the grasshopper assemblages during low density years and 79% during high density years. Dichroplus elongatus, S. lemniscata and C. pallidinota were the most abundant species in 2001, 2002 and 2003, while D. elongatus, B. brunneri and C. pallidinota in 2009. Dichroplus elongatus and D. pratensis, mixed feeders species, were positively affected by summer rainfall. This suggests that the increase in summer precipitation had a positive effect on the quantity and quality forage production, affecting these grasshopper populations. Scotussa lemniscata and C. pallidinota were negatively affected by winter and fall temperature, possibly affecting the embryonic development before diapause and hatching. Dichroplus elongatus and D. pratensis were associated with highly disturbed pastures, S. lemniscata with pastures and B. bruneri and D. maculipennis with halophilous grasslands. Covasacris pallidinota was closely associated with halophilous grasslands and moderately disturbed pastures. Weather conditions changed over the years, with 2001, 2002 and 2003 having excessive rainfall while 2008 and 2009 were the driest years since the study started. We suggest that although seasonal precipitation and temperature had no significant effect on total grasshopper density, these weather variables and plant communities had differential influence on the dominant grasshopper species. PMID:22220572

de Wysiecki, Maria Laura; Arturi, Marcelo; Torrusio, Sandra; Cigliano, Maria Marta

2011-01-01

77

Influence of weather variables and plant communities on grasshopper density in the Southern Pampas, Argentina.  

PubMed

A study was conducted to evaluate the influence of weather (precipitation and temperature) and plant communities on grasshopper density over a 14-year period (1996-2009) in Benito Juárez County, Southern Pampas, Argentina. Total density strongly varied among plant communities. Highest values were registered in 2001 and 2003 in highly disturbed pastures and in 2002 and 2009 in halophilous grasslands. Native grasslands had the lowest density values. Seasonal precipitation and temperature had no significant effect on total grasshopper density. Dichroplus elongatus (Giglio-Tos) (Orthoptera: Acridoidea), Covasacris pallidinota (Bruner), Dichroplus pratensis Bruner, Scotussa lemniscata Stål, Borellia bruneri (Rehn) and Dichroplus maculipennis (Blanchard) comprised, on average, 64% of the grasshopper assemblages during low density years and 79% during high density years. Dichroplus elongatus, S. lemniscata and C. pallidinota were the most abundant species in 2001, 2002 and 2003, while D. elongatus, B. brunneri and C. pallidinota in 2009. Dichroplus elongatus and D. pratensis, mixed feeders species, were positively affected by summer rainfall. This suggests that the increase in summer precipitation had a positive effect on the quantity and quality forage production, affecting these grasshopper populations. Scotussa lemniscata and C. pallidinota were negatively affected by winter and fall temperature, possibly affecting the embryonic development before diapause and hatching. Dichroplus elongatus and D. pratensis were associated with highly disturbed pastures, S. lemniscata with pastures and B. bruneri and D. maculipennis with halophilous grasslands. Covasacris pallidinota was closely associated with halophilous grasslands and moderately disturbed pastures. Weather conditions changed over the years, with 2001, 2002 and 2003 having excessive rainfall while 2008 and 2009 were the driest years since the study started. We suggest that although seasonal precipitation and temperature had no significant effect on total grasshopper density, these weather variables and plant communities had differential influence on the dominant grasshopper species. PMID:22220572

de Wysiecki, María Laura; Arturi, Marcelo; Torrusio, Sandra; Cigliano, María Marta

2011-01-01

78

Using Space Weather Variability in Evaluating the Radiation Environment Design Specifications for NASA's Constellation Program  

NASA Technical Reports Server (NTRS)

NASA's Constellation program, initiated to fulfill the Vision for Space Exploration, will create a new generation of vehicles for servicing low Earth orbit, the Moon, and beyond. Space radiation specifications for space system hardware are necessarily conservative to assure system robustness for a wide range of space environments. Spectral models of solar particle events and trapped radiation belt environments are used to develop the design requirements for estimating total ionizing radiation dose, displacement damage, and single event effects for Constellation hardware. We first describe the rationale using the spectra chosen to establish the total dose and single event design environmental specifications for Constellation systems. We then compare variability of the space environment to the spectral design models to evaluate their applicability as conservative design environments and potential vulnerabilities to extreme space weather events

Coffey, Victoria N.; Blackwell, William C.; Minow, Joseph I.; Bruce, Margaret B.; Howard, James W.

2007-01-01

79

Earth Tides, Ocean Tides and Tidal Loading  

Microsoft Academic Search

The distortion of the Earth's gravitational potential field by the M2 ocean tide has been calculated, accounting for both the elastic deformation of the Earth and the self potential of the water. The potential field generated by the ocean tide is almost everywhere greater than a tenth, and over much of the ocean is half as large as the lunar

W. E. Farrell

1973-01-01

80

The Amazon hydrometeorology: Climatology, variability and links to changes in weather patterns  

NASA Astrophysics Data System (ADS)

My thesis focuses on improving the quantification of the hydrological cycle and understanding the atmospheric processes that link weather to climate in the Amazon River basin. By using ERA40 and independent observations, I assess how well we can estimate the surface water budget in the Amazon River basin. I find that ERA40 basin wide annual precipitation (P) overall agrees with observations showing a slight underestimation of 10% in average, whereas runoff (R) is underestimated by a larger margin (˜25%). Observed residual of precipitation and runoff (denoted as P-R) is better estimated by ERA40 P-R than actual ET which includes soil moisture nudging. The causes for said discrepancies were found to partly relate to soil moisture nudging that needs to be applied during the dry season to produce realistic ET and compensate for the low soil moisture recharge during the previous wet season. Insufficient recharge may in part be caused by underestimation of rainfall amount and intensity; moreover the shallow root layer in the model does not represent the deep soil water reservoir characteristic of the Amazonian forest. Whether the hydrological cycle and weather patterns in the Amazon have changed during the past few decades is a highly debatable but central question for detecting climate change in the region. The second part of my thesis focus on the physical links between rainfall changes detected in observations, and changes of synoptic scale systems as represented by ERA40. My results suggest that an observed delayed wet season onset is consistent with a decreasing number of cold air incursion (CAI) days in southern Amazon for the period 1979--2001. The variability of CAI into southern Amazon is related to the variability of SST upstream of South America in the tropical Pacific and Indian Oceans. A Singular Value Decomposition Analysis (SVD) between CAI days and global SST reveal three main modes of co-variability. The first mode describes the effect of the El Nino-Southern Oscillation. During El Nino (La Nina) a strong (weak) subtropical jet stream over South America tends to prevent transient systems from moving to southern Amazon, resulting in decreased (increased) CAI days during SON. The second mode of co-variability shows an anomalously warm western Indian Ocean also related to strong subtropical jet stream, except the jet is positioned farther north in South America, which along with the absence of a well defined subpolar jet stream, favors the northward displacement of transient waves into central South America, but show little response in southern Amazon. The CAI days reconstructed from the first and second modes do not present any significant trend in southern Amazon. CAI days reconstructed from the third mode of co-variability on the other hand, reproduces the SON observed trend in almost its entirety. The third mode of co-variability describes negative (positive) anomalies in CAI days associated with cold (warm) SST anomalies in the eastern tropical Pacific, anomalous wavetrain in the Southern Hemisphere and Walker Cell displacement that are unfavorable (favorable) to the incursion of CAI into southern Amazon. The temporal evolution of this mode correlates negatively with the Pacific Decadal Oscillation, suggesting that the recent gradual shift in PDO polarity reflected on the interannual response of Southern Pacific atmospheric patterns, hence on the behavior of transients propagation. The negative PDO index and its related atmospheric patterns are in agreement with the reduced observed CAI days, which also related to a delayed wet season onset in the southern Amazon.

Fernandes, Katia De Avila

81

Waves and Tides  

NSDL National Science Digital Library

In this 7-10 day investigation, learners develop an understanding of waves and tides and their motion through discussion, demonstration, and hands-on activities. Learners demonstrate wave motion in containers and create marigrams to show local tide data and to compare tide patterns from different parts of the world. Learners consider whether waves or tides account for the movement of bath toys to their final locations. This detailed lesson plan includes learner hand-outs, evaluation questions, and curricular connections.

Grant, Alaska S.

2011-01-01

82

HarborTides.com  

NSDL National Science Digital Library

HarborTides.com is a neat, user-friendly facility for tide information for over 2,500 harbors in the US (and Bermuda). Users may browse by state or search by zip code for information on high and low tides, sunrise and sunset, and longitude and latitude for every harbor. After filling out a form for free membership, users can also print out monthly tide tables.

83

Large-Scale Variability of Single Galactic Wolf-Rayet Stars: Using Gemini Poor Weather Time to Improve the Survey  

NASA Astrophysics Data System (ADS)

A spectroscopic survey of all single (or not known to be binary) Galactic Wolf-Rayet stars in search for large scale variability has been conducted. Using the “poor weather time” at the Gemini Observatory, this survey could be increased with the inclusion of stars with v < 16 mag. Here is a short update of our latest results.

Chené, A.-N.; St-Louis, N.; Moffat, A. F. J.

2012-12-01

84

Pseudowhitening of weather Radar signals to improve spectral moment and polarimetric variable estimates at low signal-to-noise ratios  

Microsoft Academic Search

Pseudowhitening of oversampled signals in range is proposed as a method to improve the performance of spectral moment and polarimetric variable estimators on weather surveillance radars. In an attempt to overcome the noise sensitivity of the whitening transformation, a solution based on the minimum mean-square-error criterion is considered first; however, this transformation is less practical than whitening because it requires

Sebastián M. Torres; Christopher D. Curtis; J. R. Cruz

2004-01-01

85

Moon and Tide Patterns  

NSDL National Science Digital Library

In this activity, students will use Moon and tide data from the internet to construct charts and answer questions about the patterns they see. They will be reminded that the Moon has something to do with ocean tides and will discover what the connections are. They will also discover when tides, moonrise and moonset, and phases of the Moon occur.

Passow, Michael

86

What Causes Tides?  

ERIC Educational Resources Information Center

The phenomenon of tides has a faraway source. This rise and fall of the water level over a period of several hours is a result of the gravitational pull of the Moon and the Sun on Earth's oceans. Tides exhibit predictable cycles on daily, monthly, and yearly scales. The magnitude of the tides is dependent on the position of the Earth and Moon in…

Donovan, Deborah

2004-01-01

87

Do weather changes influence pain levels in women with fibromyalgia, and can psychosocial variables moderate these influences?  

NASA Astrophysics Data System (ADS)

The aim of this study was to examine the association between fibromyalgia pain and weather, and to investigate whether psychosocial factors influence this relationship. Women with chronic widespread pain/fibromyalgia ( N = 50) enrolled in a larger study, were recruited from a 4-week inpatient rehabilitation program in Norway ( 2009-2010), and reported their pain and psychological factors up to three times per day (morning, afternoon, evening) for 5 weeks. These ratings were then related to the official local weather parameters. Barometric pressure recorded simultaneously impacted pain significantly while temperature, relative humidity, and solar flux did not. No psychological variables influenced the weather-pain interaction. No weather parameter predicted change in the subsequent pain measures. The magnitude of the inverse association between pain and barometric pressure was very small, and none of the psychological variables studied influenced the association between pain and barometric pressure. All in all, the evidence for a strong weather-pain association in fibromyalgia seems limited at best.

Smedslund, Geir; Eide, Hilde; Kristjansdottir, Ólöf Birna; Nes, Andrea Aparecida Gonçalves; Sexton, Harold; Fors, Egil A.

2014-09-01

88

Climate Variability and Weather Extremes: Model-Simulated and Historical Data. Chapter 9  

NASA Technical Reports Server (NTRS)

Extremes in weather and climate encompass a wide array of phenomena including tropical storms, mesoscale convective systems, snowstorms, floods, heat waves, and drought. Understanding how such extremes might change in the future requires an understanding of their past behavior including their connections to large-scale climate variability and trends. Previous studies suggest that the most robust findings concerning changes in short-term extremes are those that can be most directly (though not completely) tied to the increase in the global mean temperatures. These include the findings that (IPCC 2007): There has been a widespread reduction in the number of frost days in mid-latitude regions in recent decades, an increase in the number of warm extremes, particularly warm nights, and a reduction in the number of cold extremes, particularly cold nights. For North America in particular (CCSP SAP 3.3, 2008): There are fewer unusually cold days during the last few decades. The last 10 years have seen a lower number of severe cold waves than for any other 10-year period in the historical record that dates back to 1895. There has been a decrease in the number of frost days and a lengthening of the frost-free season, particularly in the western part of North America. Other aspects of extremes such as the changes in storminess have a less clear signature of long term change, with considerable interannual, and decadal variability that can obscure any climate change signal. Nevertheless, regarding extratropical storms (CCSP SAP 3.3, 2008): The balance of evidence suggests that there has been a northward shift in the tracks of strong low pressure systems (storms) in both the North Atlantic and North Pacific basins. For North America: Regional analyses suggest that there has been a decrease in snowstorms in the South and lower Midwest of the United States, and an increase in snowstorms in the upper Midwest and Northeast. Despite the progress already made, our understanding of the basic mechanisms by which extremes vary is incomplete. As noted in IPCC (2007), Incomplete global data sets and remaining model uncertainties still restrict understanding of changes in extremes and attribution of changes to causes, although understanding of changes in the intensity, frequency and risk of extremes has improved. Separating decadal and other shorter-term variability from climate change impacts on extremes requires a better understanding of the processes responsible for the changes. In particular, the physical processes linking sea surface temperature changes to regional climate changes, and a basic understanding of the inherent variability in weather extremes and how that is impacted by atmospheric circulation changes at subseasonal to decadal and longer time scales, are still inadequately understood. Given the fundamental limitations in the time span and quality of global observations, substantial progress on these issues will rely increasingly on improvements in models, with observations continuing to play a critical role, though less as a detection tool, and more as a tool for addressing physical processes, and to insure the quality of the climate models and the verisimilitude of the simulations (CCSP SAP 1.3, 2008).

Schubert, Siegfried D.; Lim, Young-Kwon

2012-01-01

89

Prospects for downscaling seasonal precipitation variability using conditioned weather generator parameters  

NASA Astrophysics Data System (ADS)

This paper explores the use of synoptic-scale predictor variables to downscale both high- and low-frequency components of daily precipitation at sites across the British Isles. Part I investigates seasonal and inter-annual variations in three weather generator parameters with respect to concurrent variations in a North Atlantic Oscillation (NAO) index and area-average sea surface temperature (SST) anomalies. Marked spatial gradients were found in the strength of the associated correlation fields using rainfall data for the period 1961-90. For example, the persistence of winter wet-spells was most strongly correlated with the NAO index in NW Scotland, and the persistence of autumn dry-spells with SST anomalies in SE England. At such locations, North Atlantic conditioning accounted for over 40% of the inter-annual variability of precipitation occurrence. In Part II, three downscaling models were compared using independent daily precipitation data for sites located in the regions of strongest North Atlantic forcing. The parameters of Model M were implicitly conditioned by three regional airflow indices; the parameters of Model X were explicitly conditioned by either the NAO index or SST anomalies and daily vorticity; and the parameters of Model U (a three-parameter stochastic rainfall model) were unconditional. Overall, the conditional models displayed greater skill for monthly rainfall statistics relative to Model U (the control), but still did not completely remove overdispersion. On comparing Models M and X, it was evident that explicit conditioning did bestow additional advantages for the chosen sites and seasons of greatest forcing. However, further research is required to determine the generality of these results for other regions and periods of the rainfall record.

Wilby, R. L.; Conway, D.; Jones, P. D.

2002-04-01

90

Temporal Variability of Fair-Weather Cumulus Statistics at the ACRF SGP Site  

SciTech Connect

Continental fair-weather cumuli exhibit significant diurnal, day-to-day, and year-to-year variability. This study describes the climatology of cloud macroscale properties, including the cloud-base height, cloud-top height, cloud thickness, and cloud chord length over the U.S. Department of Energy¹s Atmospheric Radiation Measurement (ARM) Climate Research Facility (ARCF) Southern Great Plains (SGP) site. The diurnal cycle of cloud fraction, cloud-base height, and cloud-thickness were well defined. The cloud fraction reached its maximum value near 14:00 CST. The average cloud-base height increased throughout the day, while the average cloud thickness decreased with time. In contrast to the other cloud properties, the average cloud-chord length remained nearly constant throughout the day. The sensitivity of the cloud properties to the year-to-year variability and to changes in low-level moisture were compared. The cloud-base height was found to be sensitive to both the year and the low-level moisture, the cloud thickness was much more sensitive to the year then to the low-level moisture, and the cloud fraction and cloud chord length were more sensitive to the low-level moisture than to the year. Distributions of the cloud-chord length over the ARCF SGP site were computed and were well fit by an exponential distribution. The contribution of clouds of each cloud-chord length to the total cloud fraction was computed, and it was found the clouds with a chord length of about 1 km contributed the most to the observed cloud fraction.

Berg, Larry K.; Kassianov, Evgueni I.

2008-07-01

91

Star Gardens: Tides  

NSDL National Science Digital Library

In this activity students will learn that tides are caused by the gravitational pull of the moon and sun on the surface of the ocean. They will discover that tides are predictable changes in sea level that occur at regular intervals, and rise and fall roughly twice during each 24-hour period. Students will also find that tides follow the phases of the moon, with the highest and lowest tides occurring during the full and new moons. They will create a tide calendar by plotting a month-long tidal curve on an ordinary pictorial calendar. They will realize that because tides affect both the natural environment and human activities in many ways, it is important to know when they will occur.

92

The Causes of Tides  

NSDL National Science Digital Library

This document explains the predictable and periodic movements of ocean waters that are known as tides and how they are produced by the gravitational forces of the moon and sun. It describes how gravitational attraction and centrifugal force create bulges on either side of the Earth (the high tides), and how two coinciding and simultaneous low tides occur at equal distances around the earth between them. It also explains tidal range and why it varies greatly with geographic location.

93

The Causes of Tides  

NSDL National Science Digital Library

This document explains the predictable and periodic movements of ocean waters that are known as tides and how they are produced by the gravitational forces of the moon and sun. It describes how gravitational attraction and centrifugal force create bulges on either side of the Earth (the high tides), and how two coinciding and simultaneous low tides occur at equal distances around the earth between them. It also explains tidal range and why it varies greatly with geographic location.

Oberrecht, Kenn

2007-01-30

94

Regional Differences in the Growing Incidence of Dengue Fever in Vietnam Explained by Weather Variability  

PubMed Central

Dengue fever is a major health problem in Vietnam, but its incidence differs from province to province. To understand this at the local level, we assessed the effect of four weather components (humidity, rainfall, temperature and sunshine) on the number of dengue cases in nine provinces of Vietnam. Monthly data from 1999 to 2009 were analysed by time-series regression using negative binomial models. A test for heterogeneity was applied to assess the weather-dengue association in the provinces. Those associations were significantly heterogeneous (for temperature, humidity, and sunshine: P < 0.001 heterogeneity test; for rainfall: P = 0.018 heterogeneity test). This confirms that weather components strongly affect dengue transmission at a lag time of 0 to 3 months, with considerable variation in their influence among different areas in Vietnam. This finding may promote the strategic prevention of dengue disease by suggesting specific plans at the local level, rather than a nationally unified approach. PMID:24808744

Vu, Ha Hai; Okumura, Junko; Hashizume, Masahiro; Tran, Duong Nhu; Yamamoto, Taro

2014-01-01

95

Oxidative weathering chemical migration under variably saturated conditions and supergene copper enrichment  

Microsoft Academic Search

Transport of oxygen gas from the land surface through an unsaturated zone has a strong influence on oxidative weathering processes. Oxidation of sulfide minerals such as pyrite (FeSâ), one of the most common naturally occurring minerals, is the primary source of acid drainage from mines and waste rock piles. Here we present a detailed numerical model of supergene copper enrichment

Tianfu Xu; K. Pruess; G. Brimhall

1999-01-01

96

Simulation of extreme temperature events by a stochastic weather generator: effects of interdiurnal and interannual variability reproduction  

NASA Astrophysics Data System (ADS)

A WGEN-like four-variate (maximum and minimum temperature, precipitation and solar radiation) stochastic daily weather generator Met&Roll is used to provide synthetic weather series for models simulating crop growth and hydrological regime in present and changed climate conditions. Since impacts of climate change will be largely affected by changes in climate variability and extreme events, present climate models should satisfactorily reproduce both interdiurnal and interannual variability of the weather series and the occurrence of extremes. Three improvements of Met&Roll aiming at a better reproduction of interdiurnal and interannual variability have been introduced: (i) lag-0 and lag-1 correlations among solar radiation and daily extreme temperatures are allowed to vary during a year; (ii) a Markov chain of the third order (instead of the first order) is used to model precipitation occurrence; (iii) the synthetic daily weather series is adjusted to fit the series of the monthly means, which is generated using the four-variate first-order autoregressive (AR) model.Model performance regarding the simulation of extreme temperature events is evaluated against observations at 83 stations covering most of Europe. None of the improvements of the generator lead to a generally better reproduction of extreme high and low temperatures (1 day extremes); the basic version of the generator performs best for annual maxima, whereas the inclusion of the annual cycle of correlations slightly enhances the simulation of annual minima. For multiday extremes, the incorporation of the monthly generator tends to improve heat- and cold-wave characteristics, mainly the chaining of hot and cold days in spells; in western and central Europe, it improves (worsens) the simulation of heat waves (cold waves). Bad reproduction of most extreme event characteristics out of western and central Europe indicates a limited applicability of a generator based on the first-order AR model for temperature outside the mild climate zone and in areas with a high degree of continentality. The validity of assumptions of the generator should be tested using weather series related to a given area before its application in impact studies, and, if necessary, adjustments must be made.

Kyselý, Jan; Dubrovský, Martin

2005-02-01

97

Oxidative weathering chemical migration under variably saturated conditions and supergene copper enrichment  

SciTech Connect

Transport of oxygen gas from the land surface through an unsaturated zone has a strong influence on oxidative weathering processes. Oxidation of sulfide minerals such as pyrite (FeS{sub 2}), one of the most common naturally occurring minerals, is the primary source of acid drainage from mines and waste rock piles. Here we present a detailed numerical model of supergene copper enrichment that involves the oxidative weathering of pyrite (FeS{sub 2}) and chalcopyrite (CuFeS{sub 2}), and acidification that causes mobilization of metals in the unsaturated zone, with subsequent formation of enriched ore deposits of chalcocite (CuS) and covellite (Cu{sub 2}S) in the reducing conditions below the water table. We examine and identify some significant conceptual and computational issues regarding the oxidative weathering processes through the modeling tool. The dissolution of gaseous oxygen induced by the oxidation reduces oxygen partial pressure, as well as the total pressure of the gas phase. As a result, the gas flow is modified, then the liquid phase flow. Results indicate that this reaction effect on the fluid flow may not be important under ambient conditions, and gas diffusion can be a more important mechanism for oxygen supply than gas or liquid advection. Acidification, mobilization of metals, and alteration of primary minerals mostly take place in unsaturated zone (oxidizing), while precipitation of secondary minerals mainly occurs in saturated zone (reducing). The water table may be considered as an interface between oxidizing and reducing zones. Moving water table due to change of infiltration results in moving oxidizing zone and redistributing aqueous chemical constitutes and secondary mineral deposits. The oxidative weathering processes are difficult to model numerically, because concentrations of redox sensitive chemical species such as O{sub 2}(aq), SO{sub 4}{sup 2-} and HS{sup -} may change over tens of orders of magnitude between oxidizing and reducing conditions. In order to simulate substantial reaction progress over geologic time, one can benefit from the quasi-stationary state (QSS) approximation. A significant saving of computing time using QSS is demonstrated through the example. In addition, changes in porosity and permeability due to mineral dissolution and precipitation are also addressed in some degree. Even though oxidative weathering is sensitive to many factors, this work demonstrates that our model provides a comprehensive suite of process modeling capabilities, which could serve as a prototype for oxidative weathering processes with broad significance for geoscientific, engineering, and environmental applications.

Xu, Tianfu; Pruess, K.; Brimhall, G.

1999-04-01

98

A variable vertical resolution weather model with an explicitly resolved planetary boundary layer  

NASA Technical Reports Server (NTRS)

A version of the fourth order weather model incorporating surface wind stress data from SEASAT A scatterometer observations is presented. The Monin-Obukhov similarity theory is used to relate winds at the top of the surface layer to surface wind stress. A reasonable approximation of surface fluxes of heat, moisture, and momentum are obtainable using this method. A Richardson number adjustment scheme based on the ideas of Chang is used to allow for turbulence effects.

Helfand, H. M.

1981-01-01

99

A variable data rate satellite user terminal for multimedia communication able to react against weather impairments (DASIA 2002)  

NASA Astrophysics Data System (ADS)

In the frame of Ground Segment products LABEN - a Finmeccanica Company - is developing an advanced Satellite User Terminal for Multimedia Communication able to react against weather impairments. LABEN has been responsible during the Phase B for the design of the Resource Sharing Experiment (RSE) Earth Terminal of the DAVID Program (ASI). The RSE shall demonstrate conceptual and operational feasibility of the variable data rate link with a LEO satellite (DAVID). This abstract wants to provide a brief description of the proposed system and to outline the near future evolution of these Multimedia Earth Terminals linked to new services and applications.

Bux, W.; Ferrari, M.; D'Ambrosio, A.

2002-07-01

100

Studying the space weather variability of the high-latitude ionosphere by using a physics-based data assimilation model  

NASA Astrophysics Data System (ADS)

The high-latitude ionosphere is a very dynamic region in the solar-terrestrial environment. Frequent disturbances in the region can adversely affect numerous military and civilian technologies. Accurate specifications and forecasts of the high-latitude electrodynamic and plasma structures have fundamental space weather importance for enabling mitigation of adverse effects. We developed a data assimilation model for the high-latitude ionosphere. The model consists of a set of first-principle physical models and an ensemble Kalman filter and assimilates the real-time (or rear real-time) observational measurements. Presently, the model can ingest the magnetic perturbation from the ground-based magnetometers in the high-latitude regions, magnetic measurements of IRIDIUM satellites, SuperDARN line-of-sight velocity, and in-situ drift velocity measured by DMSP satellites. In this presentation, we will show the preliminary results of a systematic study of the space weather variability of the electrodynamic and plasma structures in the high-latitude ionosphere by using our data assimilation model. The study covers the periods of various seasons and geomagnetic conditions. With these results, we would demonstrate the dynamic nature of the high-latitude ionosphere and elucidate the importance of the data assimilation technique for accurate specification and forecasting of space weather.

Zhu, L.; Schunk, R. W.; Scherliess, L.; Eccles, J. V.; Sojka, J. J.

2012-12-01

101

Studying the space weather variability of the high-latitude ionosphere by using a physics-based data assimilation model  

NASA Astrophysics Data System (ADS)

The high-latitude ionosphere is a very dynamic region in the solar-terrestrial environment. Frequent disturbances in the region can adversely affect numerous military and civilian technologies. Accurate specifications and forecasts of the high-latitude electrodynamic and plasma structures have fundamental space weather importance for enabling mitigation of adverse effects. We developed a data assimilation model for the high-latitude ionosphere. The model consists of a set of first-principle physical models and an ensemble Kalman filter and assimilates the real-time (or rear real-time) observational measurements. Presently, the model can ingest the magnetic perturbation from the ground-based magnetometers in the high-latitude regions, magnetic measurements of IRIDIUM satellites, SuperDARN line-of-sight velocity, and in-situ drift velocity measured by DMSP satellites. In this presentation, we will show the preliminary results of a systematic study of the space weather variability of the electrodynamic and plasma structures in the high-latitude ionosphere by using our data assimilation model. The study covers the periods of various seasons and geomagnetic conditions. With these results, we would demonstrate the dynamic nature of the high-latitude ionosphere and elucidate the importance of the data assimilation technique for accurate specification and forecasting of space weather.

Zhu, Lie; Eccles, Vince; Scherliess, Ludger; Sojka, Jan J.; Schunk, Robert

2012-07-01

102

The potential impacts of climate variability and change on health impacts of extreme weather events in the United States.  

PubMed Central

Extreme weather events such as precipitation extremes and severe storms cause hundreds of deaths and injuries annually in the United States. Climate change may alter the frequency, timing, intensity, and duration of these events. Increases in heavy precipitation have occurred over the past century. Future climate scenarios show likely increases in the frequency of extreme precipitation events, including precipitation during hurricanes, raising the risk of floods. Frequencies of tornadoes and hurricanes cannot reliably be projected. Injury and death are the direct health impacts most often associated with natural disasters. Secondary effects, mediated by changes in ecologic systems and public health infrastructure, also occur. The health impacts of extreme weather events hinge on the vulnerabilities and recovery capacities of the natural environment and the local population. Relevant variables include building codes, warning systems, disaster policies, evacuation plans, and relief efforts. There are many federal, state, and local government agencies and nongovernmental organizations involved in planning for and responding to natural disasters in the United States. Future research on health impacts of extreme weather events should focus on improving climate models to project any trends in regional extreme events and as a result improve public health preparedness and mitigation. Epidemiologic studies of health effects beyond the direct impacts of disaster will provide a more accurate measure of the full health impacts and will assist in planning and resource allocation. PMID:11359686

Greenough, G; McGeehin, M; Bernard, S M; Trtanj, J; Riad, J; Engelberg, D

2001-01-01

103

The Earth Tides.  

ERIC Educational Resources Information Center

In addition to oceans, the earth is subjected to tidal stresses and undergoes tidal deformations. Discusses origin of tides, tidal stresses, and methods of determining tidal deformations (including gravity, tilt, and strain meters). (JN)

Levine, Judah

1982-01-01

104

Phytoplankton variability in Lake Fraijanes, Costa Rica, in response to local weather variation.  

PubMed

Phytoplankton species show a variety in morphology which is the result of adaptations to pelagic life including responses to fluctuations in water column dynamics driven by weather conditions. This has been reported in the oceans and in Northern temperate lakes. In order to observe whether tropical freshwater phytoplankton responds to seasonal variation in weather, the weekly variation in temperature of the water column and phytoplankton composition was studied in Lake Fraijanes, Costa Rica, a shallow (6.2m) lake at 1 640m above sea level. A chain of data loggers for temperature was placed in the deepest point in the lake to register temperature every hour at four different depths, and phytoplankton samples were retrieved every week for a year. Additional monthly samples for nutrients were taken at two depths. Notwithstanding its shallowness, the lake developed a thermal gradient which kept the water column stratified for several months during dry season. Whole lake overturns occurred during cold spells with intense precipitation. Phytoplankton changed throughout the year mainly through a shift in dominant taxa. From September to February the lake was frequently mixed by rain storms and windy weather. At this time, phytoplankton was dominated by Chlorococcal green algae. From March to June, the lake was stratified and warmer. Phytoplankton became dominated by Cyanobateria, mainly colonial Chroococcales. The rainy season started again in May 2009. During June and July the lake started to mix intermittently during rain events and phytoplankton showed a brief increase in the contribution of Chlorococcales. These changes fitted well to a general model of phytoplankton succession based on functional groups identified according to their morphology and adaptations. PMID:25102633

Umaña-Villalobos, Gerardo

2014-06-01

105

A novel underwater weather station  

Microsoft Academic Search

A new form of underwater weather station has been designed for long term recording with great reliability and low power consumption.The novelty of the instrument lies in its use of a non-destructive,non-volatile magnetic memory. The original instrument was designed as a tide gauge capable of recording deep-sea tides on the ocean floor for at least a year's duration. Analog data

J. Matthews; Gil Mimken

1974-01-01

106

Carbon dioxide variability during cold front passages and fair weather days at a forested mountaintop site  

NASA Astrophysics Data System (ADS)

This study describes temporal carbon dioxide (CO 2) changes at a new meteorological site on a mountaintop in the Virginia Blue Ridge Mountains during the first year of measurements. Continental mountaintop locations are increasingly being used for CO 2 monitoring, and investigations are needed to better understand measurements made at these locations. We focus on CO 2 mixing ratio changes on days with cold front passages and on fair weather days. Changes in CO 2 mixing ratios are largest during cold front passages outside the growing season and on clear, fair weather days in the growing season. 67% (60%) of the frontal passages during the non-growing (growing) season have larger postfrontal than prefrontal CO 2 mixing ratios. The increase in CO 2 mixing ratio around the frontal passage is short-lived and coincides with changes in CO and O 3. The CO 2 increase can therefore be used as an additional criterion to determine the timing of frontal passages at the mountaintop station. The CO 2 increase can be explained by an accumulation of trace gases along frontal boundaries. The magnitude and duration of the CO 2 increase is affected by the wind speed and direction that determine the source region of the postfrontal air. Southward-moving fronts result in the largest prolonged period of elevated CO 2, consistent with the postfrontal advection of air from the Northeastern United States where anthropogenic contributions are relatively large compared to other areas in the footprint of the mountaintop station. These anthropogenic contributions to the CO 2 changes are confirmed through concurrent CO measurements and output from NOAA's CarbonTracker model.

Lee, Temple R.; De Wekker, Stephan F. J.; Andrews, Arlyn E.; Kofler, Jonathan; Williams, Jonathan

2012-01-01

107

Spatial variability of trace metals and inorganic nutrients in surface waters of Todos Santos Bay, México in the summer of 2005 during a red tide algal bloom.  

PubMed

Dissolved and particulate metals (Ag, Cd, Co, Cu, Ni, and Zn) and nutrients (PO(4), NO(3), and H(4)SiO(4)) were measured in Todos Santos Bay (TSB) in August 2005. Two sources producing local gradients were identified: one from a dredge discharge area (DDA) and another south of the port and a creek. The average concentrations of dissolved Cd and Zn (1.3 and 15.6 nM, respectively) were higher by one order of magnitude than the surrounding Pacific waters, even during upwelling, and it is attributed to the presence of a widespread and long-lasting red tide coupled with some degree of local pollution. A clear spatial gradient (10 to 6 pM), from coast to offshore, of dissolved Ag was evident, indicating the influence of anthropogenic inputs. The particulate fraction of all metals, except Cu, showed a factor of ~3 decrease in concentrations from the DDA to the interior of the bay. The metal distributions were related to the bay's circulation by means of a numerical model that shows a basically surface-wind-driven offshore current with subsurface compensation currents toward the coast. Additionally, the model shows strong vertical currents over the DDA. Principal component analysis revealed three possible processes that could be influencing the metal concentrations within TSB: anthropogenic inputs (Cd, Ag, and Co), biological proceses (NO(3), Zn, and Cu), and upwelling and mixing (PO(4), H(4)SiO(4), Cd, and Ni). The most striking finding of this study was the extremely high Cd concentrations, which have been only reported in highly contaminated areas. As there was a strong red tide, it is hypothesized that the dinoflagellates are assimilating the Cd, which is rapidly remineralized and being concentrated on the stratified surface layers. PMID:18726538

Lares, M L; Marinone, S G; Rivera-Duarte, I; Beck, A; Sañudo-Wilhelmy, S

2009-05-01

108

Waves: Internal Tides  

NASA Technical Reports Server (NTRS)

Oceanic internal tides are internal waves with tidal periodicities. They are ubiquitous throughout the ocean, although generally more pronounced near large bathymetric features such as mid-ocean ridges and continental slopes. The internal vertical displacements associated with these waves can be extraordinarily large. Near some shelf breaks where the surface tides are strong, internal displacements (e.g., of an isothermal surface) can exceed 200 meters. Displacements of 10 meters in the open ocean are not uncommon. The associated current velocities are usually comparable to or larger than the currents of the surface tide. On continental shelves internal tides can occasionally generate packets of internal solitons, which are detectable in remote sensing imagery. Other common nonlinear features are generation of higher harmonics (e.g., 6-hr waves) and wave breaking. Internal tides are known to be an important energy source for mixing of shelf waters. Recent research suggests that they may also be a significant energy source for deep-ocean mixing.

Ray, Richard D.

1999-01-01

109

Effects of weather variability and soil parameter uncertainty on the soil-crop-climate system  

SciTech Connect

The variability of crop and soil states due to uncertain climatic inputs and soil properties is quantified using a mathematical representation of the physiological, biochemical, hydrological, and physical processes related to plant growth. The components of the state-space model of the soil-crop-climate interactions are a plant growth, a moisture transport, and a solute transport model. A linear model for the perturbations of the state and the inputs around the nominal (first-order mean) values is derived. The linear model is used for second-moment uncertainty propagation due to fluctuations of the climatic forcing in time and due to the spatial variability of the soil properties. The most important climatic variables affecting crop production are identified in a case study. Correlation of climatic inputs between days is found to increase the crop yield variance. Significant variance reduction is found in transforming random soil properties to soil-state variables and then to plant-state variables. 31 refs., 4 figs.

Protopapas, A.L. (Polytechnic Univ., Brooklyn, NY (United States)); Bras, R.L. (Massachusetts Institute of Technology, Cambridge (United States))

1993-04-01

110

Tides and Water Levels  

NSDL National Science Digital Library

This site serves as a gateway to three sections devoted to learning about tides and water levels: an online tutorial, an list of links to tidal resources, and formal lesson plans. The tutorial is an overview of the complex systems that govern the movement of tides and water levels. It is content rich, is presented in easy-to-understand language, and includes many illustrative and interactive graphics to visually enhance the text. The links direct users to specific tidal and current data offered within the National Ocean Service and National Oceanic and Atmospheric Administration's family of products. Lesson plans integrate information presented in the tutorial with online data. These lesson plans have been developed for students in grades 9-12 and focus on the forces that cause and effect tides, analysis of the variations in tidal patterns and what conditions may cause them, and the effect of lunar cycles on living organisms.

111

Types of Tides and Tidal Currents  

NSDL National Science Digital Library

This text discusses differences in ocean tides. Along America's Atlantic Coast, two high and low tides occur daily. Such tides are called semidiurnal. On the north shore of the Gulf of Mexico, the tide is diurnal, meaning that it moves in and out again once a day while in the Pacific Northwest, there are mixed tides, two highs and two lows a day, characterized by significant disparity between successive tides. The site also explains flood current or flood tide, ebb current or ebb tide, and slack water or slack tide. There is a detailed discussion of spring tide and neap tide and also an explanation of the difference between riptide and tiderip.

112

Integrating interannual climate variability forecasts into weather-indexed crop insurance. The case of Malawi, Kenya and Tanzania  

NASA Astrophysics Data System (ADS)

In this study we explore the potential for re-insurance schemes built on regional climatic forecasts. We focus on micro-insurance contracts indexed on precipitation in 9 villages in Kenya, Tanzania (Eastern Africa) and Malawi (Southern Africa), and analyze the precipitation patterns and payouts resulting from El Niño Southern Oscillation (ENSO). The inability to manage future climate risk represents a “poverty trap” for several African regions. Weather shocks can potentially destabilize not only household, but also entire countries. Governments in drought-prone countries, donors and relief agencies are becoming aware of the importance to develop an ex-ante risk management framework for weather risk. Joint efforts to develop innovative mechanisms to spread and pool risk such as microinsurance and microcredit are currently being designed in several developing countries. While ENSO is an important component in modulating the rainfall regime in tropical Africa, the micro-insurance experiments currently under development to address drought risk among smallholder farmers in this region do not take into account ENSO monitoring or forecasting yet. ENSO forecasts could be integrated in the contracts and reinsurance schemes could be designed at the continental scale taking advantage of the different impact of ENSO on different regions. ENSO is associated to a bipolar precipitation pattern in Southern and Eastern Africa. La Niña years (i.e. Cold ENSO Episodes) are characterized by dry climate in Eastern Africa and wet climate in Southern Africa. During El Niño (or Warm Episode) the precipitation dipole is inverted, and Eastern Africa experiences increased probability for above normal rainfall (Halpert and Ropelewski, 1992, Journal of Climate). Our study represents the first exercise in trying to include ENSO forecasts in micro weather index insurance contract design. We analyzed the contracts payouts with respect to climate variability. In particular (i) we simulated possible payouts using historical precipitation data and analyzed the differences between years with different ENSO states from 1961 to 2005; (ii) we applied Monte Carlo methods to simulate precipitation distributions in each location and calculated the mean and variance of payouts associated to different ENSO states. The results obtained from historical precipitation data indicate that more abundant rainfall reduces payouts and the risk of loan default during La Niña in southern Kenya and Malawi, during El Niño in Tanzania. The results of the Monte Carlo simulations confirm our findings. Our results suggest that re-insurance schemes could be successfully designed to exploit the anti-correlation patterns related to interannual climate variability for different regions in Africa. Moreover, the exploratory framework presented can potentially be refined applied to other regions (e.g. Central and Latin America).

Vicarelli, M.; Giannini, A.; Osgood, D.

2009-12-01

113

A Sensitive Search for Variability in Late L Dwarfs: The Quest for Weather  

E-print Network

We have conducted a photometric monitoring program of 3 field late-L brown dwarfs looking for evidence of non-axisymmetric structure or temporal variability in their photospheres. The observations were performed using Spitzer/IRAC 4.5 and 8 micron bandpasses and were designed to cover at least one rotational period of each object. One-sigma RMS (root mean squared) uncertainties of less than 3 mmag at 4.5 micron and around 9 mmag at 8 micron were achieved. Two out of the three objects studied exhibit some modulation in their light curves at 4.5 micron - but not 8 micron - with periods of 7.4 hr and 4.6 hr and peak-to-peak amplitudes of 10 mmag and 8 mmag. Although the lack of detectable 8 micron variation suggests an instrumental origin for the detected variations, the data may nevertheless still be consistent with intrinsic variability since the shorter wavelength IRAC bandpasses probe more deeply into late L dwarf atmospheres than the longer wavelengths. A cloud feature occupying a small percentage (1-2 %) of the visible hemisphere could account for the observed amplitude of variation. If, instead, the variability is indeed instrumental in origin, then our non-variable L dwarfs could be either completely covered with clouds or objects whose clouds are smaller and uniformly distributed. Such scenarios would lead to very small photometric variations. Followup IRAC photometry at 3.6 and 5.8 micron bandpasses should distinguish between the two cases. In any event, the present observations provide the most sensitive search to date for structure in the photospheres of late-L dwarfs at mid-IR wavelengths, and our photometry provides stringent upper limits to the extent to which the photospheres of these transition L dwarfs are structured.

M. Morales-Calderon; J. R. Stauffer; J. Davy Kirkpatrick; S. Carey; C. R. Gelino; D. Barrado y Navascues; L. Rebull; P. Lowrance; M. S. Marley; D. Charbonneau; B. M. Patten; S. T. Megeath; D. Buzasi

2006-07-24

114

Tidal friction for semidiurnal tides  

Microsoft Academic Search

The quadratic law of bottom friction demands an increased frictional coefficient for the S2 and N2 tides with respect to a dominant M2 tidal signal. A numerical model of the semidiurnal tides in the northeast Atlantic gives an increase in friction of ˜35% for the N2, S2 and K2 tides with respect to the M2 tide and this value is

R. D. Pingree; D. K. Griffiths

1987-01-01

115

Climate Variability, Weather and Enteric Disease Incidence in New Zealand: Time Series Analysis  

PubMed Central

Background Evaluating the influence of climate variability on enteric disease incidence may improve our ability to predict how climate change may affect these diseases. Objectives To examine the associations between regional climate variability and enteric disease incidence in New Zealand. Methods Associations between monthly climate and enteric diseases (campylobacteriosis, salmonellosis, cryptosporidiosis, giardiasis) were investigated using Seasonal Auto Regressive Integrated Moving Average (SARIMA) models. Results No climatic factors were significantly associated with campylobacteriosis and giardiasis, with similar predictive power for univariate and multivariate models. Cryptosporidiosis was positively associated with average temperature of the previous month (??=? 0.130, SE?=? 0.060, p <0.01) and inversely related to the Southern Oscillation Index (SOI) two months previously (??=? ?0.008, SE?=? 0.004, p <0.05). By contrast, salmonellosis was positively associated with temperature (? ?=?0.110, SE?=?0.020, p<0.001) of the current month and SOI of the current (? ?=?0.005, SE?=?0.002, p<0.050) and previous month (? ?=?0.005, SE?=?0.002, p<0.05). Forecasting accuracy of the multivariate models for cryptosporidiosis and salmonellosis were significantly higher. Conclusions Although spatial heterogeneity in the observed patterns could not be assessed, these results suggest that temporally lagged relationships between climate variables and national communicable disease incidence data can contribute to disease prediction models and early warning systems. PMID:24376707

Lal, Aparna; Ikeda, Takayoshi; French, Nigel; Baker, Michael G.; Hales, Simon

2013-01-01

116

Science 101: What causes tides?  

NSDL National Science Digital Library

Tides exhibit predictable cycles on daily, monthly, and yearly scales. The magnitude of the tides is dependent on the position of the Earth and Moon in relation to the Sun, but is also influenced by other factors. This is a brief introduction to what causes tides.

Donovan, Deborah

2004-07-01

117

Florida's Red Tide Infestation  

NSDL National Science Digital Library

This CBS news article reports a toxic algae bloom that spread along the Florida's west coast in 2001, threatening the wildlife of Tampa Bay's estuary. The article briefly discusses the cause of the red tide and its affect on the shellfish industry.

News, Cbs

118

How reliable is the offline linkage of Weather Research & Forecasting Model (WRF) and Variable Infiltration Capacity (VIC) model?  

NASA Astrophysics Data System (ADS)

The aim for this research is to evaluate the ability of the offline linkage of Weather Research & Forecasting Model (WRF) and Variable Infiltration Capacity (VIC) model to produce hydrological, e.g. evaporation (ET), soil moisture (SM), runoff, and baseflow. First, the VIC model was run by using observed meteorological data and calibrated in the Upper Mississippi River Basin (UMRB) from 1980 to 2010. Subsequently, a simulation based on an offline linkage of WRF and VIC was performed in the UMRB with the calibrated parameters established above from 2006 to 2009. Standard measured meteorological inputs to VIC were replaced by WRF meteorological variables. A spatiotemporal comparison of offline simulated ET, SM, runoff, and baseflow produced by the VIC calibrated run (base data) and by the offline linkage run was conducted. The results showed that the offline linkage of VIC with WRF was able to achieve good agreement in the simulation of monthly and daily soil moisture, and monthly evaporation. This suggests the VIC linkage should function without causing a large change in the moisture budget. However, the offline linkage showed most disagreement in daily and monthly runoff, and baseflow which is related to errors in WRF precipitation.

Tang, Chunling; Dennis, Robin L.

2014-05-01

119

Hurricane Sandy Storm Tide Mapper  

NSDL National Science Digital Library

United States Geological Survey (USGS) provides real-time map-based information from USGS storm tide sensors. The data is reflected on the Hurricane Sandy Tide Mapper. The mapper provides location information, site photos and data for storm tide and inland flooding. In addition, the data from these sensors is used to create models of the precise time the storm-tide arrived, how ocean and inland water levels changed during the storm, the depth of the storm-tide throughout the event, and how long it took for the water to recede.

120

Red Tide in the Northeast  

NSDL National Science Digital Library

This Rhode Island Sea Grant fact sheet provides information about red tide algal blooms in New England. It addresses where and when red tides occur, how to know if shellfish are safe to consume, and other important facts about red tide. The site features a black and white picture of the dinoflagellate responsible for red tide in New England and a regional map of where infected shell fish have been found. It also features links to other red tide related sites and a list of pertinent reading material.

Ely, Elenor; Ross, Neil W.; Island, Sea G.

121

On the sub-grid-scale variability of oceanic winds and the accuracy of numerical weather prediction models as deduced from QuikSCAT backscatter distributions  

Microsoft Academic Search

Observed probability distributions of QuikSCAT scatterometer cross sections are matched to expected distributions calculated using a Geophysical Model Function (GMF) with a wind speed threshold and inherent wind variability on the subfootprint scale and also on grid scales of numerical weather prediction (NWP) models. Two independent approaches are taken: In one, the 3-D sample size is 2° × 2° and

Naoya Suzuki; Mark A. Donelan; William J. Plant

2007-01-01

122

A Fourier series model to predict hourly heating and cooling energy use in commercial buildings with outdoor temperature as the only weather variable  

Microsoft Academic Search

Accurate modeling of hourly heating and cooling energy use in commercial buildings can be achieved by a Generalized Fourier Series (GFS) approach involving weather variables such as dry-bulb temperature, specific humidity and horizontal solar flux. However, there are situations when only temperature data is available. The objective of this paper is to (i) describe development of a variant of the

A. Dhar; T. A. Reddy; D. E. Claridge

1999-01-01

123

Altimetry, Orbits and Tides  

NASA Technical Reports Server (NTRS)

The nature of the orbit error and its effect on the sea surface heights calculated with satellite altimetry are explained. The elementary concepts of celestial mechanics required to follow a general discussion of the problem are included. Consideration of errors in the orbits of satellites with precisely repeating ground tracks (SEASAT, TOPEX, ERS-1, POSEIDON, amongst past and future altimeter satellites) are detailed. The theoretical conclusions are illustrated with the numerical results of computer simulations. The nature of the errors in this type of orbits is such that this error can be filtered out by using height differences along repeating (overlapping) passes. This makes them particularly valuable for the study and monitoring of changes in the sea surface, such as tides. Elements of tidal theory, showing how these principles can be combined with those pertinent to the orbit error to make direct maps of the tides using altimetry are presented.

Colombo, O. L.

1984-01-01

124

An objective daily Weather Type classification for Iberia since 1850; patterns, trends, variability and impact in precipitation  

NASA Astrophysics Data System (ADS)

In recent years a large number of automated classifications of atmospheric circulation patterns have been published covering the entire European continent or specific sub-regions (Huth et al., 2008). This generalized use of objective classifications results from their relatively straightforward computation but crucially from their capacity to provide simple description of typical synoptic conditions as well as their climatic and environmental impact. For this purpose, the vast majority of authors has employed the Reanalyses datasets, namely from either NCEP/NCAR or ECMWF projects. However, both these widely used datasets suffer from important caveats, namely their restricted temporal coverage, that is limited to the last six decades (NCEP/NCAR since 1948 and ECMWF since 1958). This limitation has been partially mitigated by the recent availability of continuous daily mean sea level pressure obtained within the European project EMULATE, that extended the historic records over the extra-tropical Atlantic and Europe (70°-25° N by 70° W-50° E), for the period 1850 to the present (Ansell, T. J. et al. 2006). Here we have used the extended EMULATE dataset to construct an automated version of the Lamb Weather type (WTs) classification scheme (Jones et al 1993) adapted for the center of the Iberian Peninsula. We have identified 10 basic WTs (Cyclonic, Anticyclonic and 8 directional types) following a similar methodology to that previously adopted by Trigo and DaCamara, 2000 (for Portugal) and Lorenzo et al. 2008 (for Galicia, northwestern Iberia). We have evaluated trends of monthly/seasonal frequency of each WT for the entire period and several shorter periods. Finally, we use the long-term precipitation time series from Lisbon (recently digitized) and Cadiz (southern Spain) to evaluate, the impact of each WT on the precipitation regime. It is shown that the Anticyclonic (A) type, although being the most frequent class in winter, gives a rather small contribution to the winter precipitation amount, observed on a daily basis. On the other hand, the three wettest WTs, namely the Cyclonic (C), South-westerly (SW) and Westerly (W) types, together representing roughly a third of all winter days, do account for more than 60% of the observed daily precipitation. It is shown that the large inter-annual variability of precipitation in both cities is highly related with the corresponding inter-annual variability of the wet WTs. Ansell, T. J. et al. (2006) Daily mean sea level pressure reconstructions for the European - North Atlantic region for the period 1850-2003, Journal of Climate, 19, 2717-2742, doi: 10.1175/JCLI3775.1 Huth R., Beck C., Philipp A., Demuzere M, Ustrnul Z, Cahynová M., Kyselý J., Tveito O.E. (2008) Classifications of atmospheric circulation patterns: recent advances and applications. Trends and Directions in Climate Research: Ann. N.Y. Acad. Sci. 1146:, 105-152 Jones, P. D. , M. Hulme , K. R. Briffa. (1993) A comparison of Lamb circulation types with an objective classification scheme. Int. J. Climatol. 13: 655- 663. Lorenzo M.N., Taboada J.J. and Gimeno L. (2008) Links between circulation weather types and teleconnection patterns and their influence on precipitation patterns in Galicia (NW Spain). Int. J. Climatol. Published Online: Nov 12 2007 5:30AM DOI: 10.1002/joc.1646. Trigo R.M. and Da Camara C.C. (2000) Circulation weather types and their influence on the precipitation regime in Portugal. Int. J. Climatol., 20, 1559-1581.

Ramos, A. M.; Trigo, R. M.; Lorenzo, M. N.; Vaquero, J. M.; Gallego, M. C.; Valente, M. A.; Gimeno, L.

2009-04-01

125

Deep sea tides determination from GEOS-3  

NASA Technical Reports Server (NTRS)

GEOS 3 altimeter data in a 5 degree X 5 degree square centered at 30 deg N, 70 deg W were analyzed to evaluate deep sea tide determination from a spacecraft. The signal to noise ratio of known tidal variability to altimeter measurement of sea level above the ellipsoid was 0.1. A sample was obtained in a 5 deg x 5 deg area approximately once every four days. The randomly spaced time series was analyzed using two independent least squares techniques.

Maul, G. A.; Yanaway, A.

1978-01-01

126

Tides of the Caribbean Sea  

Microsoft Academic Search

Analysis of tidal characteristics from 45 gauge locations indicates that the Caribbean Sea has a microtidal range, for the most part between 10 and 20 cm. The tide is primarily either mixed semidiurnal or mixed diurnal but a substantial section from Puerto Rico to Venezuela experiences diurnal tides. Empirical charts of six component tides (M2, S2, N2, K1, O1, and

Björn Kjerfve

1981-01-01

127

The microplankton succession in the Ría de Vigo revisited: species assemblages and the role of weather-induced, hydrodynamic variability  

NASA Astrophysics Data System (ADS)

We have analysed meteorological, hydrographic, and microplankton species abundance data, collected every 3-4 days during 1987 in the Ría de Vigo (NW Iberian Peninsula), to investigate the effect of environmental variability on the structure of the microplankton community. Three microplankton assemblages were distinguished, composed chiefly of: small- to medium-sized centric and pennate diatoms (i.e., C- and/or R-species, r-strategists), small-sized organisms from different taxonomic groups (i.e., C- or S-species, r-strategists), and medium- to large-sized dinoflagellates (i.e., S-species, K-strategists). Community changes were related to different scales of meteorological and hydrographic variability. At the seasonal scale, the succession from r-strategists towards K-strategists, or from C- and/or R-species towards S-species, was related with the annual cycle of mixing/stratification and high/low flushing. Within this seasonal pattern, a series of short-term 'successions' were identified, the onset of which co-occurred with hydrodynamic changes induced by meteorological disturbances. These results support the conclusions articulated in a previous paper on microplankton community structure during 1991 concerning: (1) the relative persistence of characteristic microplankton assemblages and their ecological interpretation in terms of adaptive strategies, and (2) the key role of weather-induced, hydrodynamic variability, especially at short-term scales, in shaping the structure of the community. The contrasting meteorology in 1987 and 1991 would explain interannual differences of community structure, such as the larger proportion of diatoms in 1991 than in 1987 due to increased intensity and duration of the upwelling seasonal cycle that year. At the species level, the early phase of the seasonal succession was characterised by the coexistence (i.e., single-species biomass, Bi?40% of total biomass) or alternating dominance ( Bi>40% BT) among (C-R) species, while the late part was characterised by the alternating dominance among species with different adaptive strategies. For instance, in September-October, the short-term succession started with the dominance of the (C-R) species Leptocylindrus danicus (˜80% of BT, during 3 weeks), followed by the (S-R) species Ceratium fusus+ Ceratium furca (˜70% of BT, 1 week), and finished with the dominance of small microheterotrophs (˜70% of BT, 2 weeks).

Nogueira, E.; Figueiras, F. G.

2005-02-01

128

The King of Tides  

NSDL National Science Digital Library

This well-constructed WebQuest begins with the announcement: âThe moon has been accused of causing the tides! Using real data collected from the Internet, your teamâs job is to bring proof one way or another!â The group task, the process for finding data and establishing proof, and the evaluation are outlined and explained clearly. However, as on all WebQuests, you will have to check the site addresses given, since Web addresses change or disappear over time. The two-week project, which depends on analysis of real data, culminates in a final report to the court.

Byles, Bill

2003-11-21

129

The ultimate high tide  

SciTech Connect

This paper discusses the possible coastal impacts of a rise in sea level. Control measures that are available to coastal communities are emphasized, including pumping of seawater into the ground, replenishing beach sand, protection or moving of potable-water intakes, elevating roadways, and building dikes. Economics will determine which, if any, measures are reasonable at a particular site. There is an upward trend in the mean CO{sub 2} concentration and predictions about the greenhouse effect are creating a rising tide of concern.

Dean, R.G. (Florida Dept. of Natural Resources, Tallahassee (USA))

1990-01-01

130

2012 Special symposium on Red tides Red-tide world  

E-print Network

2012 Special symposium on Red tides Red-tide world Date: October 26 (Friday) 2012 09, USA (PhD) Theodore J. Smayda Editor-in- chief, Harmful Algae Sandra E. Shumway Editor-in- chief, Harmful Algae Professor University of Rhode Island, USA University of Oslo, Norway (PhD) Professor

Jeong, Hae Jin

131

Europa Tide Movie  

NASA Technical Reports Server (NTRS)

[figure removed for brevity, see original site] Click on the image for Europa Tide Movie

In this movie Europa is seen in a cutaway view through two cycles of its 3.5 day orbit about the giant planet Jupiter. Like Earth, Europa is thought to have an iron core, a rocky mantle and a surface ocean of salty water. Unlike on Earth, however, this ocean is deep enough to cover the whole moon, and being far from the sun, the ocean surface is globally frozen over. Europa's orbit is eccentric, which means as it travels around Jupiter, large tides, raised by Jupiter, rise and fall. Jupiter's position relative to Europa is also seen to librate, or wobble, with the same period. This tidal kneading causes frictional heating within Europa, much in the same way a paper clip bent back and forth can get hot to the touch, as illustrated by the red glow in the interior of Europa's rocky mantle and in the lower, warmer part of its ice shell. This tidal heating is what keeps Europa's ocean liquid and could prove critical to the survival of simple organisms within the ocean, if they exist.

2007-01-01

132

Invited paper Tide distribution and  

E-print Network

­331. C 2004, by Institute of Oceanology PAS. KEYWORDS Tides Extreme tides Energy conservation Tidal power-mail:ffzk@ims.uaf.edu Manuscript received 17 June 2004, reviewed 30 July 2004, accepted 19 August 2004. Abstract Tidal power along tidal power proved to be very successful only in the last century through the tidal power plant

Kowalik, Zygmunt

133

Tide pushing shellfishers into red  

NSDL National Science Digital Library

This USA Today article provides very general information about the 2005 red tide outbreak off the Gulf of Maine. It offers possible explanations for the outbreak, what is being done to protect people from hazards related to red tide, and how the outbreak has devastated local shellfishers.

Hampson, Rick; Today, Usa

134

Tides in water saturated rock  

Microsoft Academic Search

Analysis of water table records from wells or boreholes often reveals the presence of tidal fluctuations. Amplitudes of well tides can attain several centimeters when the well or borehole is open to a confined aquifer. The phenomenon reflects extension and compression cycles of the aquifer rock, i.e. volume strain tides of a water saturated formation. Besides tidal fluctuations, barometric pressure

Hans-Joachim Kctmpel

135

Temporal and spatial variability of Fe and Mn in perched groundwater flowing through weathered argillite underlying a steep forested hillslope  

NASA Astrophysics Data System (ADS)

Groundwater flowing through weathered bedrock dictates the runoff chemistry to streams in many catchments yet; its chemical evolution has been rarely documented. In particular, observations of Fe and Mn dynamics in groundwater are extremely challenging due to their high reactivity. To preserve the sample integrity for these elements we have developed a new sampling scheme that is applicable to autosamplers; a gravitational filtration system (GFS). GFS is capable of filtering samples by gravity within 30 minutes after the sampling. The GFS samples showed a good agreement with reference samples, which were collected following the standard sampling method for trace metals (i.e. immediate filtration and acidification). Since October 2011, GFS has been employed to monitor Fe and Mn in perched groundwater that moves through weathered argillite in an intensively instrumented hillslope (Rivendell), in the Angelo Coast Range Reserve. The study site is located at the headwaters of the Eel River, northern California, characterized by a typical coastal Californian Mediterranean climate. We collected groundwater samples at 3 wells along the hillslope (upslope (W10), mid-slope (W3) and near the creek (W1)) with 1-3 day intervals. Additionally, rainwater and throughfall samples were collected at a meadow near the hillslope and at the middle of the hillslope, respectively. The results from our observations indicate that Fe and Mn exhibit distinct spatial and temporal behavior under variable hydrologic conditions. The concentrations of Fe in throughfall vs. rainwater were similar (0.45?M vs. 0.49?M), but Mn in throughfall was 10-fold higher than that in rainwater (1.2 ?M vs. 0.1 ?M). In the early rainy season, W10's water table was deep (-18m) and Fe and Mn in W10 were 30-150 nM and 1-2 ?M, respectively. As the rainy season proceeds, W10's water table rose by 4-6m, indicating the arrival of new water. At this time, Mn in W10 decreased to ~0.1 ?M, synchronizing with the water table rise, and remained unchanged throughout the season. In contrast, Fe slowly declined to <10nM for this high water table regime. During the summer recession limb, Fe and Mn concentrations in W10 began to increase. During the dry summer, the concentrations of Fe and Mn at W3 were 2-3?M and 15-20 ?M, respectively. At the beginning of the rainy seasons, the W3 water table slowly rose (<1 m) and both Fe and Mn decreased by 10-fold. The concentrations of Fe and Mn decreased to 20-70nM and 0.1 ?M, respectively, when W3's water table became highly dynamic and fluctuated about 4 m. At W1, Fe and Mn remained in the 50-100nM and 5-10 ?M ranges, respectively; however, the water table was extremely responsive to rainfall inputs. Mn in W1 was briefly diluted to <0.1 ?M during large rainstorms and rebounded within several days. In the late summer of 2012, Fe and Mn in W1 increased up to 2-6 ?M and 80 ?M, respectively. These high-frequency observations of Fe and Mn will provide insight into the biogeochemical cycles of redox sensitive elements in upland terrains, allowing for better quantitative estimation of these elemental fluxes.

Kim, H.; Bishop, J. K.

2013-12-01

136

Types of Tides and Tidal Currents  

NSDL National Science Digital Library

This text discusses differences in ocean tides. Along America\\'s Atlantic Coast, two high and low tides occur daily. Such tides are called semidiurnal. On the north shore of the Gulf of Mexico, the tide is diurnal, meaning that it moves in and out again once a day while in the Pacific Northwest, there are mixed tides, two highs and two lows a day, characterized by significant disparity between successive tides. The site also explains flood current or flood tide, ebb current or ebb tide, and slack water or slack tide. There is a detailed discussion of spring tide and neap tide and also an explanation of the difference between riptide and tiderip.

Oberrecht, Kenn

2007-01-29

137

Modelling the barotropic tide along the West-Iberian margin  

NASA Astrophysics Data System (ADS)

The present work explores the use of a numerical model to predict the barotropic tide along the West-Iberian region, extending from the Gulf of Cadiz to the Bay of Biscay and from the shelf to nearby seamounts (Gorringe and Galicia banks). The model is used, in a single isopycnal layer, to simulate the 2D propagation of the following eight principal tidal constituents: M2, S2, N2, K2, K1, O1, P1 and Q1. Astronomical tide-raising force is introduced into the equations of motion in order to improve model results. Recently updated global tide solutions are optimally combined to force a polychromatic tidal spectrum at the open boundaries. New bathymetry is built from hydrographic databases and used to increase the accuracy of the model, especially over the Portuguese continental shelf. Data from several tide gauges and acoustic Doppler current profilers are used to validate the numerical solution. Tidal amplitude and tidal current velocity solutions are evaluated by classical harmonic analysis of in situ and simulated time-series. Model outputs demonstrate the improvement of the regional hydrodynamic tide solution from earlier references. The harmonic solutions highlight small-scale variability over the shelf, and over nearby seamounts, due to the generation of diurnal continental shelf waves and topographic modulation of the semi-diurnal tidal ellipses. The barotropic forcing term is calculated over the study region and the main internal tide generation "hotspots" are revealed.

Quaresma, Luis S.; Pichon, Annick

2013-01-01

138

M2 World Ocean tide from tide gauge measurements  

NASA Astrophysics Data System (ADS)

An empirical model of the M2 oceanic tide has been computed from the harmonic constants of a subset of deep sea and coastal tide gauge measurements. The optimal interpolation of these data based on “inverse theory” uses a priori covariance functions deduced from a global hydrodynamical model. The inverse solution, produced with its associated error maps and samples of error spectra, is surprisingly good when compared to in situ data and to a hydrodynamical model.

Francis, O.; Mazzega, P.

139

Perigean Spring Tides and Apogean Neap Tides in History  

NASA Astrophysics Data System (ADS)

On January 4, 1912 - almost exactly 100 years ago - both a full Moon and a lunar perigee occurred, with these two events separated by only a few minutes of time and with the Earth near perihelion. The resulting lunar distance (356,375 km) on that date stands as the closest approach of the Moon to the Earth in an interval of more than 1400 years. The centennial of this extreme lunar perigee is an appropriate time to consider the effect of lunar distance on the range of ocean tides. At most ocean ports, spring tides of increased range occur near new and full Moon. If a lunar perigee falls near new or full Moon, then perigean spring tides of even greater range are possible. Conversely, if a lunar apogee falls near first quarter or last quarter Moon, then apogean neap tides of unusually reduced range can occur. Examples of perigean spring tides include a near-coincidence of lunar perigee and new Moon in December 1340 that may be related to a plot device in Chaucer's "The Franklin's Tale,” a Canterbury tale that describes an extreme high tide covering the rocks on the coast of Brittany in "the cold and frosty season of December.” Another example, the disaster known as the Bristol Channel Flood, occurred shortly after a lunar perigee and new Moon in January 1607. A German U-boat employed an exceptionally high perigean spring tide shortly after the new Moon of October 1939 to enter Scapa Flow by an unexpected route and sink the HMS Royal Oak. An apogean neap tide prevailed during the amphibious assault of the U. S. Marines at Tarawa in November 1943, making the eventual victory more costly because the landing craft were unable to reach the island and instead grounded on the surrounding reef.

Olson, Donald W.

2012-01-01

140

Thompson/Ocean 420/Winter 2005 Tide Dynamics 1 Tide Dynamics  

E-print Network

). Shown below are the co-range and co-tidal lines for the M2 tide. Note: "cophase" here is the same as "coThompson/Ocean 420/Winter 2005 Tide Dynamics 1 Tide Dynamics Dynamic Theory of Tides. In the equilibrium theory of tides, we assumed that the shape of the sea surface was always in equilibrium

Thompson, LuAnne

141

How Can Conventional Drinking Water Treatment Facilities Build Resilience to Climate and Weather Induced Water Supply Variability?  

EPA Science Inventory

Abstract: Water supplies are vulnerable to a host of climate- and weather-related stressors such as droughts, intense storms/flooding, snowpack depletion, sea level changes, and consequences from fires, landslides, and excessive heat or cold. Surface water resources (lakes, reser...

142

Dynamic Tides in Close Binaries  

E-print Network

The basic theory of dynamic tides in close binaries is reviewed. Particular attention is paid to resonances between dynamic tides and free oscillation modes and to the role of the apsidal-motion rate in probing the internal structure of binary components. The discussed effects are generally applicable to stars across the entire Hertzsprung-Russell diagram, including the binary OB-stars discussed at this meeting.

B. Willems

2005-11-10

143

Red Tide and Shellfish Poisoning  

NSDL National Science Digital Library

This EnviroFacts informational page discusses how red tide develops and how people might be affected by this phenomenon. It covers physical damage, oxygen depletion, direct poisoning, and indirect poisoning including paralytic shellfish poisoning (PSP), diarrhetic shellfish poisoning (DSP), neurotoxic shellfish poisoning (NSP), amnesiac shellfish poisoning (ASP), and aerosol toxins. The page concludes with a discussion of red tide and the role of the sea fisheries research institute.

Maneveldt, Gavin W.; Matthews, Sue; Pitcher, Grant; Van Der Vyver, Irma

2010-01-29

144

Modulations of Atmospheric Tides and Their Impact on UT1  

NASA Astrophysics Data System (ADS)

Sub-diurnal variations in Earth rotation parameters as obtained from space-geodetic observations contain substantial variability even after correcting for the effects of oceanic tides. Those residuals are in particular apparent at frequencies of 1, 2, and 3 cycles per solar day, where atmospheric tides are known to occur. Those tides are principally excited by water vapor absorption and ozone heating in the middle atmosphere, but are also affected by the absorption of solar energy at the surface and corresponding radiative or convective vertical transfer processes, that might vary over a wide range of time-scales. Based on atmospheric data from the latest ECMWF re-analysis ERA Interim, the contributions of atmospheric tides to variations in UT1 with periods of 12 and 24 hours are described by corresponding zonal standing waves in both vertically varying winds and atmospheric pressure at the Earth's surface. Whereas tidal signatures in the surface pressure are found to be rather stable in time, substantial variability of the tidal variations are found in the troposheric winds. By means of both typical seasonal conditions as well as rather exceptional atmospheric state related to the 1997 ENSO event, the potential range of the impact of time-varying atmospheric tides on UT1 will be discussed.

Dobslaw, H.; Kadow, C.

2012-12-01

145

Tides in Colliding Galaxies  

NASA Astrophysics Data System (ADS)

Long tails and streams of stars are the most noticeable traces of galaxy collisions. However, their tidal origin was recognized only less than 50 years ago and more than 10 years after their first observations. This review describes how the idea of galactic tides has emerged thanks to advances in numerical simulations, from the first simulations that included tens of particles to the most sophisticated ones with tens of millions of them and state-of-the-art hydrodynamical prescriptions. Theoretical aspects pertaining to the formation of tidal tails are then presented. The third part turns to observations and underlines the need for collecting deep multi-wavelength data to tackle the variety of physical processes exhibited by collisional debris. Tidal tails are not just stellar structures, but turn out to contain all the components usually found in galactic disks, in particular atomic/molecular gas and dust. They host star-forming complexes and are able to form star-clusters or even second-generation dwarf galaxies. The final part of the review discusses what tidal tails can tell us (or not) about the structure and the content of present-day galaxies, including their dark components, and explains how they may be used to probe the past evolution of galaxies and the history of their mass assembly. On-going deep wide-field surveys disclose many new low-surface brightness structures in the nearby Universe, offering great opportunities for attempting galactic archeology with tidal tails.

Duc, Pierre-Alain; Renaud, Florent

146

Tides and Modern Geodesy  

NASA Technical Reports Server (NTRS)

In modem high-precision geodesy, and especially in modem space geodesy, every measurement that one makes contains tidal signals. Generally these signals are considered noise and must somehow be eliminated. The stringent requirements of the latest space geodetic missions place severe demands on tidal models. On the other hand, these missions provide the strongest data for improving tidal models. In particular, TOPEX/POSEIDON altimetry and LAGEOS laser ranging have improved models to such an extent that new geophysical information about the ocean and the solid Earth are coming to light. Presumably GRACE intersatellite ranging data will also add to this information. This paper discusses several of these new geophysical results, with special emphasis given to the dissipation of tidal energy. Strong constraints have recently been placed on the partitioning of energy dissipation among the ocean, atmosphere, and solid earth and between the deep and shallow ocean. The dissipation in deep water is associated with internal tides and has potentially important implications for understanding the ocean's thermohaline circulation.

Ray, Richard D.; Chao, Benjamin F. (Technical Monitor)

2002-01-01

147

Tides in colliding galaxies  

E-print Network

Long tails and streams of stars are the most noticeable upshots of galaxy collisions. Their origin as gravitational, tidal, disturbances has however been recognized only less than fifty years ago and more than ten years after their first observations. This Review describes how the idea of galactic tides emerged, in particular thanks to the advances in numerical simulations, from the first ones that included tens of particles to the most sophisticated ones with tens of millions of them and state-of-the-art hydrodynamical prescriptions. Theoretical aspects pertaining to the formation of tidal tails are then presented. The third part of the review turns to observations and underlines the need for collecting deep multi-wavelength data to tackle the variety of physical processes exhibited by collisional debris. Tidal tails are not just stellar structures, but turn out to contain all the components usually found in galactic disks, in particular atomic / molecular gas and dust. They host star-forming complexes and a...

Duc, Pierre-Alain

2011-01-01

148

Weather Vane  

NSDL National Science Digital Library

In this meteorology activity, learners build weather vanes using straws, paperclips, and cardstock. Learners will explore wind and air resistance as well as how weather vanes are used to understand and predict weather.

Workshop, Fresno C.

2011-01-01

149

Weather Watch  

ERIC Educational Resources Information Center

Suggests a number of ways in which Federal Aviation Agency weather report printouts can be used in teaching the weather section of meteorology. These weather sequence reports can be obtained free of charge at most major airports. (JR)

Bratt, Herschell Marvin

1973-01-01

150

Red Tide off Texas Coast  

NASA Technical Reports Server (NTRS)

Red tides (algae) bloomed late this summer along a 300-mile stretch of Texas' Gulf Coast, killing millions of fish and shellfish as well as making some people sick. State officials are calling this the worst red tide bloom in 14 years. The algae produces a poison that paralyzes fish and prevents them from breathing. There is concern that the deadly algae could impact or even wipe out this year's oyster harvest in Texas, which usually peaks during the Thanksgiving and Christmas holidays. The red tides were first observed off the Texas coast in mid-August and have been growing steadily in size ever since. Red tides tend to bloom and subside rapidly, depending upon changes in wind speed and direction, water temperature, salinity, and rainfall patterns (as the algae doesn't do as well in fresher water). This true-color image of the Texas Gulf Coast was acquired on September 29, 2000, by the Moderate-resolution Imaging Spectroradiometer (MODIS) flying aboard NASA's Terra spacecraft. The red tide can be seen as the dark reddish discoloration in the ocean running southwest to northeast along the coast. In this scene, the bloom appears to be concentrated north and east of Corpus Christi, just off Matagorda Island. The image was made at 500-meter resolution using a combination of MODIS' visible bands 1 (red), 4 (green), and 3 (blue). The city of Houston can be seen clearly as the large, greyish cluster of pixels to the north and west of Galveston Bay, which is about mid-way up the coastline in this image. Also visible in this image are plumes of smoke, perhaps wildfires, both to the north and northeast of Houston. For more information about red tides, refer to the Texas Red Tide Web site. Image courtesy Andrey Savtchenko, MODIS Data Support Team, and the MODIS Ocean Team, NASA's Goddard Space Flight Center

2002-01-01

151

Wide variability in physical activity environments and weather-related outdoor play policies in child-care centers within a single county of Ohio  

PubMed Central

Objectives To examine the variability of physical activity environments and outdoor play-policies in child-care centers, and to determine if they are associated with center demographic characteristics Design Telephone survey—the Early Learning Environments Physical Activity and Nutrition Telephone Survey (ELEPhANTS) Setting Child-care centers in Hamilton County (Cincinnati area), Ohio, 2008–9. Participants Directors of all 185 licensed full-time child-care centers in Hamilton County. Outcome Measures Descriptive measures of center playground and indoor physical activity environments, and weather-related outdoor-play policies. Results 162 (88%) centers responded. Most (93%) centers reported an on-site playground, but only half reported their playgrounds as large, at least 1/3rd covered in shade, or having a variety of portable play equipment. Only half reported having a dedicated indoor gross-motor room where children could be active during inclement weather. Only 20% of centers allowed children to go outside in temperatures below 32°F, and 43% of centers reported allowing children outdoors during light rain. A higher percent of children receiving tuition-assistance was associated with lower quality physical activity facilities and stricter weather-related practices. National accreditation was associated with more physical-activity promoting practices. Conclusion We found considerable variability in the indoor and outdoor playground offerings among child-care centers, even within a single county of Ohio. Per center policy and limited inside options, children’s active opportunities are curtailed due to sub-freezing temperatures or light rain. Policy change and parent/teacher education may be needed to ensure children achieve ample opportunity for daily physical activity. PMID:21199969

Copeland, Kristen A; Sherman, Susan N; Khoury, Jane C; Foster, Karla E; Saelens, Brian E; Kalkwarf, Heidi J

2011-01-01

152

The Lunar Semidiurnal Tide in the Thermosphere  

NASA Astrophysics Data System (ADS)

Renewed interest in lunar tidal influences on the ionosphere-thermosphere (IT) system has emerged in connection with Fejer's discovery of a possible connection between stratospheric warmings and lunar tidal perturbations of the equatorial ionosphere. By virtue of its gravitational force on the solid earth, oceans and atmosphere, the moon produces perturbations in the temperature, density, pressure and wind fields of earth's atmosphere. Lunar tidal winds in the dynamo region (ca. 100-150 km) can furthermore generate electric fields that map into the F-region and redistribute ionospheric plasma. Direct penetration (propagation) of lunar tides to F-region heights can also transport ionospheric plasma. In this paper we examine the global structure of the main M2 (period = 12.42h) lunar tide through examination of temperatures measured by the TIMED SABER instrument between 90 and 110 km and densities inferred from accelerometers on the CHAMP and GRACE satellites in the 350-550 altitude range. Ten-year mean SABER temperature amplitudes are of order 5-10 K while the corresponding density perturbations approach amplitudes of order 5% at 360 km and 10% at 480 km. Evidence for significant longitude variability is also presented. Global-Scale Wave Model (GSWM) simulations agree in seasonal-latitudinal structure with the above results, and moreover provide estimates of E- and F-region winds. The observed amplitudes are large enough to impose non-negligible day-to-day variability on the IT system.

Forbes, J.; Zhang, X.

2012-04-01

153

Seasonal Asymmetry in Martian Tides  

NASA Astrophysics Data System (ADS)

Several studies have unveiled the sources of nonmigrating tides on Mars, these sources traditionally including the dramatic changes in the martian topography and the non-uniformity of the surface thermal properties. These surface contrasts in combination with the solar diurnal cycle lead to production of a spectrum of nonmigrating tides with varying strengths. Dust plays a central role in the tidal generation process as it intercepts solar radiation in the troposphere, thus injecting the diurnal cycle directly into the atmosphere. The role of dust in shaping every facet of of the martian dynamics has long been known and studied including its contribution to tidal excitation. In this presentation we show how the interplay between surface-generated tidal components and those excited by longitudinally-varying solar absorption due to dust, explains the seasonal asymmetry of nonmigrating tides as seen in middle-atmosphere Mars Climate Sounder (MCS).

Moudden, Youssef; Forbes, Jeffrey

2014-05-01

154

Severe Weather  

ERIC Educational Resources Information Center

Educating the public about safety issues related to severe weather is part of the National Oceanic and Atmospheric Administration's (NOAA) mission. This month's insert, Severe Weather, has been created by NOAA to help educate the public about hazardous weather conditions. The four types of severe weather highlighted in this poster are hurricanes,…

Forde, Evan B.

2004-01-01

155

Severe Weather  

ERIC Educational Resources Information Center

Educating the public about safety issues related to severe weather is part of the National Oceanic and Atmospheric Administration's (NOAA) mission. This article deals with a poster entitled, "Severe Weather," that has been created by NOAA to help educate the public about hazardous weather conditions. The four types of severe weather highlighted in…

Forde, Evan B.

2004-01-01

156

Disaggregation of screen-level variables in a numerical weather prediction model with an explicit simulation of subgrid-scale land-surface heterogeneity  

NASA Astrophysics Data System (ADS)

The earth's surface is characterized by small-scale heterogeneity attributable to variability in land cover, soil characteristics and orography. In atmospheric models, this small-scale variability can be partially accounted for by the so-called mosaic approach, i.e., by computing the land-surface processes on a grid with an explicit higher horizontal resolution than the atmosphere. The mosaic approach does, however, not account for the subgrid-scale variability in the screen-level atmospheric parameters, part of which might be related to land-surface heterogeneity itself. In this study, simulations with the numerical weather prediction model COSMO are shown, employing the mosaic approach together with a spatial disaggregation of the atmospheric forcing by the screen-level variables to the subgrid-scale. The atmospheric model is run with a 2.8 km horizontal grid resolution while the land surface processes are computed on a 400-m horizontal grid. The disaggregation of the driving atmospheric variables at screen-level is achieved by a three-step statistical downscaling with rules learnt from high-resolution fully coupled COSMO simulations, where both, atmosphere and surface, were simulated on a 400-m grid. The steps encompass spline interpolation of the grid scale variables, conditional regression based on the high-resolution runs, and an optional stochastic noise generator which restores the variability of the downscaled variables. Simulations for a number of case studies have been carried out, with or without mosaic surface representation and with or without atmospheric disaggregation, and evaluated with respect to the surface state variables and the turbulent surface exchange fluxes of sensible and latent heat. The results are compared with the high-resolution fully coupled COSMO simulations. The results clearly demonstrate the high importance of accounting for subgrid-scale surface heterogeneity. It is shown that the atmospheric disaggregation leads to clear additional improvements in the structures of the two-dimensional surface state variable fields, but to only marginally impacts on the simulation of the turbulent surface exchange fluxes. A detailed analysis of these results identifies strongly correlated errors in atmospheric and surface variables in the mosaic approach as the main reason for the latter. The effects of these errors largely cancel out in the flux parameterization, and thus explain the comparably good results for the fluxes in the mosaic approach without atmospheric disaggregation despite inferior performance for the surface state variables themselves. Inserting noise in the disaggregation scheme leads to a deterioration of the results.

Schomburg, A.; Venema, V.; Ament, F.; Simmer, C.

2012-05-01

157

UM Weather  

NSDL National Science Digital Library

Sponsored by The Weather Underground at the University of Michigan at Ann Arbor, UM Weather bills itself as the "Internet's premier source of weather information." The site offers several general audience tools such as the Fast Forecast for any city in the US, ski weather, and weather cams. But, it also provides access to over two dozen weather software packages, a new computer model forecasts page, and most impressively a list of close to 400 other weather related Web sites. Professionals and researchers will appreciate the non-technical feel of the site and the valuable information they can procure from it.

1994-01-01

158

WWW Tide and Current Predictor  

NSDL National Science Digital Library

From the University of South Carolina's Wethey Lab Homepage, the tide and current predictor contains up-to-date basic predictions and a format for obtaining customized predictions. Access to data is organized by location. Location choices include US Upper East Coast (Maine through Virginia), US Lower East Coast (North Carolina through Florida Keys), US Gulf Coast sites (East to West), US West Coast sites (North to South), Northern sites (except Japan) outside contiguous US (East to West), Southern sites outside contiguous US (East to West), and Japan and nearby sites (North to South). Also, the site includes answers to FAQs concerning this tide predictor.

159

Baroclinic tides in an axially symmetric basin  

E-print Network

INTRODUCTION AViD LITERATURE REVIEW . 1 Barotropic Tides . 2 Recognition and Observation of Baroclinic Tides 3 Baroclinic Tide Generation Mechanisms 4 t'Iodels of Baroclinic Tides . , 5 Overview of the Present Study . . RESEARCH METHODS 1 Linearized... Equations of Motion on an f-plane. . . . 2 Local Vertical Structure Functions . 3 Coupled Normal Mode Equations . 4 The Coupling Matrix . . 5 Transform of Modal Equations to the Frequency Domain . 6 Inner and Outer Boundary Conditions . 7 Solution...

Dever, Edward Paul

2012-06-07

160

4, 371398, 2007 Internal tides and  

E-print Network

OSD 4, 371­398, 2007 Internal tides and energy fluxes over Great Meteor Seamount T. Gerkema and H-access review for the journal Ocean Science Internal tides and energy fluxes over Great Meteor Seamount T@nioz.nl) 371 #12;OSD 4, 371­398, 2007 Internal tides and energy fluxes over Great Meteor Seamount T. Gerkema

Boyer, Edmond

161

Ocean tide measurement by seasat altimeter data  

Microsoft Academic Search

Tides in the deep ocean have been measured directly by satellite altimetry, independent of knowledge of earth tides, ocean loading, tidal dissipation, or ocean bottom topography. Conventional tide predictions for the deep ocean are sensitive to uncertainties in these parameters. Correction of Seasat altimetry for orbit uncertainty, and subsequent harmonic analysis of sub-track crossover differences, provides a simple and direct

R. Brown

1982-01-01

162

Awaiting High Tide to Set Block Nets  

USGS Multimedia Gallery

Sampling fish within the intertidal zone of a mangrove forest requires setting a block net at the interface between forest and river at high tide, then retrieving the net at low tide.  Here researchers await high tide to set the nets seen in the boat. ...

2010-08-13

163

Secular Changes in the Solar Semidiurnal Tide of the Western North Atlantic Ocean  

NASA Technical Reports Server (NTRS)

An analysis of twentieth century tide gauge records reveals that the solar semidiurnal tide S, has been decreasing in amplitude along the eastern coast of North America and at the mid-ocean site Bermuda. In relative terms the observed rates are unusually large, of order 10% per century. Periods of greatest change, however, are inconsistent among the stations, and roughly half the stations show increasing amplitude since the late 1990s. Excepting the Gulf of Maine, lunar tides are either static or slightly increasing in amplitude; a few stations show decreases. Large changes in solar, but not lunar, tides suggest causes related to variable radiational forcing, but the hypothesis is at present unproven. Citation: Ray, R. D. (2009), Secular changes in the solar semidiurnal tide of the western North Atlantic Ocean

Ray, Richard D.

2009-01-01

164

The magnetic tides of Honolulu  

NASA Astrophysics Data System (ADS)

We review the phenomenon of time-stationary, periodic quiet-time geomagnetic tides. These are generated by the ionospheric and oceanic dynamos, and, to a lesser-extent, by the quiet-time magnetosphere, and they are affected by currents induced in the Earth's electrically conducting interior. We examine historical time series of hourly magnetic-vector measurements made at the Honolulu observatory. We construct high-resolution, frequency-domain Lomb-periodogram and maximum-entropy power spectra that reveal a panorama of stationary harmonics across periods from 0.1 to 10000.0-d, including harmonics that result from amplitude and phase modulation. We identify solar-diurnal tides and their annual and solar-cycle sideband modulations, lunar semi-diurnal tides and their solar-diurnal sidebands, and tides due to precession of lunar eccentricity and nodes. We provide evidence that a method intended for separating the ionospheric and oceanic dynamo signals by midnight subsampling of observatory data time series is prone to frequency-domain aliasing. The tidal signals we summarize in this review can be used to test our fundamental understanding of the dynamics of the quiet-time ionosphere and magnetosphere, induction in the ocean and in the electrically conducting interior of the Earth, and they are useful for defining a quiet-time baseline against which magnetospheric-storm intensity is measured.

Love, J. J.; Rigler, E. J.

2013-12-01

165

Source apportionment of PM2.5 at multiple sites in Venice (Italy): Spatial variability and the role of weather  

NASA Astrophysics Data System (ADS)

This study investigates the chemical speciation of fine particulate matter (PM2.5) collected at three sites in the Venice area, eastern Po Valley (Italy). This area is one of the few hot spots left in Europe where levels of PM2.5 frequently breach EU target values and cause a serious risk for public health. Elemental composition, inorganic ions and polycyclic aromatic hydrocarbon concentrations were quantified in 448 PM2.5 samples and the multiple-site PMF receptor model was based on the elemental and inorganic ion data. Six factors associated with potential sources were quantified, namely, secondary sulfate, ammonium nitrate and combustions, fossil fuels, traffic, industrial and glassmaking. Source apportionment results were further processed using a series of chemometric tools for returning additional information about the seasonal and spatial changes of factors extracted by the PMF analysis. In addition, PMF results were also studied in combination with weather conditions and PAH concentrations revealing that sources of secondary nitrate and sulfate are homogeneously distributed throughout the area, while remaining pollutant sources may have a distinct origin. PMF results were cluster analyzed to sort out samples with similar source profiles and then the wind roses of grouped samples were examined to assess the role of wind speed and direction on PM2.5 pollution and chemistry. The tested tools and the results obtained can be used for air quality assessment studies and air pollution reduction strategies.

Masiol, Mauro; Squizzato, Stefania; Rampazzo, Giancarlo; Pavoni, Bruno

2014-12-01

166

Impacts of weather variability on turbulent heat fluxes in Phoenix, AZ and Portland, OR 1 2 12 2 3 3  

E-print Network

simulates the surface energy balance of urban areas at the local or neighborhood scale 2 (0.01­100 km and a local- esearch Question RHow does the mix of land cover affect the summer daytime surface energy balance, and what are the relative contributions of climate and variable land cover on the surface energy balance

Hall, Sharon J.

167

Weather on the Nearest Brown Dwarfs: Resolved Simultaneous Multi-wavelength Variability Monitoring of WISE J104915.57-531906.1AB  

NASA Astrophysics Data System (ADS)

We present two epochs of MPG/ESO 2.2 m GROND simultaneous six-band (r'i'z' JHK) photometric monitoring of the closest known L/T transition brown dwarf binary WISE J104915.57-531906.1AB. We report here the first resolved variability monitoring of both the T0.5 and L7.5 components. We obtained 4 hr of focused observations on the night of 2013 April 22 (UT), as well as 4 hr of defocused (unresolved) observations on the night of 2013 April 16 (UT). We note a number of robust trends in our light curves. The r' and i' light curves appear to be anti-correlated with z' and H for the T0.5 component and in the unresolved light curve. In the defocused dataset, J appears correlated with z' and H and anti-correlated with r' and i', while in the focused dataset we measure no variability for J at the level of our photometric precision, likely due to evolving weather phenomena. In our focused T0.5 component light curve, the K band light curve displays a significant phase offset relative to both H and z'. We argue that the measured phase offsets are correlated with atmospheric pressure probed at each band, as estimated from one-dimensional atmospheric models. We also report low-amplitude variability in i' and z' intrinsic to the L7.5 component.

Biller, Beth A.; Crossfield, Ian J. M.; Mancini, Luigi; Ciceri, Simona; Southworth, John; Kopytova, Taisiya G.; Bonnefoy, Mickaël; Deacon, Niall R.; Schlieder, Joshua E.; Buenzli, Esther; Brandner, Wolfgang; Allard, France; Homeier, Derek; Freytag, Bernd; Bailer-Jones, Coryn A. L.; Greiner, Jochen; Henning, Thomas; Goldman, Bertrand

2013-11-01

168

Table 1 Highest tides (tide ranges) of the global ocean Country Site Tide range (m)  

E-print Network

Puerto Rio Gallegos 13.3 Russia Bay of Mezen (White Sea) 10.0 Russia Penzhinskaya Guba 13.4 (Sea into narrow bays and river estuaries along a coastline. For instance, the tides in the Bay of Fundy in Canada coast of Austra- lia, and the Okhotsk Sea of Russia. Table 1 contains ranges of amplitude for some

Gorban, Alexander N.

169

Mechanical Weathering  

NSDL National Science Digital Library

This activity was designed to give students an opportunity to realize that all rocks weather mechanically and each specific rock type has its own particular rate of weathering. Students discover that mechanical weathering is the process of breaking down bedrock into smaller fragments by physical as opposed to chemical means and that rock weathering, although it seems to occur slowly in human terms, is an extremely significant part of the rock cycle. They will learn that weathered rock materials are called sediments and are the structural basis for soils and can also be compacted into sedimentary rock. Students will realize that rock weathering rates vary widely depending on mineral content, texture, rock type, and climate and that differential weathering (varying weathering rates for two or more rock types in physical contact with each other) has given rise to some of the world's most breathtaking scenery.

170

Weathering Animation  

NSDL National Science Digital Library

Weathering is the term that describes all the processes that break down rocks in the environment near the Earth's surface. This module will help you to understand two weathering processes: mechanical and chemical.

2002-01-01

171

Weather Forecasting  

NSDL National Science Digital Library

This website, supplied by Annenberg / CPB, discusses weather satellites, Doppler radar, and additional tools forecasters use to predict the weather. Students can find a wind chill calculator along with a brief discussion of the history of forecasting and weather lore. Once you have a firm grasp on the science of weather forecasting, be sure to check out the other sections of this site, which include: "ice and snow," "our changing climate," "the water cycle," and "powerful storms."

2008-03-27

172

Nonmigrating tidal heating and MLT tidal wind variability due to the El Niño-Southern Oscillation  

NASA Astrophysics Data System (ADS)

Tides forced by large-scale weather systems in the tropical troposphere introduce significant longitudinal and local time variability in the upper atmosphere. This paper presents variability of tidal harmonics of the latent heating from 2002 to 2011 associated with the El Niño-Southern Oscillation (ENSO) and the tidal wind response in the mesosphere/lower thermosphere (MLT) region. Emphasis is on the strong ENSO cycle 2009-2011. Latent tidal heating rates are computed from TRMM satellite precipitation data, with added radiative heating from MERRA reanalysis, as functions of time, latitude, and altitude. The heating rates for the two most affected nonmigrating tides (DE3 and DE2) are examined and compared with MLT tidal wind variability from TIDI/TIMED. Principal component analysis (PCA) is used to identify the tidal modes most affected by ENSO. Our results indicate that the tidal response to ENSO is largest during winter for both of the tides, with the largest response occurring in the DE3 tidal winds during the La Niña phase, with an increase of roughly 70% for the winter months of 2010/2011, and negligible response during the El Niño phase. The ENSO effect in the tidal forcing closely resembles the first symmetric and antisymmetric Hough modes of DE3 and DE2, thus being an efficient mechanism to transmit the ENSO signal into the MLT tides.

Warner, K.; Oberheide, J.

2014-02-01

173

Antarctic Weather  

NSDL National Science Digital Library

Visitors to this site can read a discussion about the weather in Anarctica, including why it is so cold, how weather observations are conducted there, and what role the continent plays in the global weather system. Links to related topics, a wind chill calculator, and a Fahrenheit-Celsius-Kelvin temperature converter are also provided.

174

The tides of Titan.  

PubMed

We have detected in Cassini spacecraft data the signature of the periodic tidal stresses within Titan, driven by the eccentricity (e = 0.028) of its 16-day orbit around Saturn. Precise measurements of the acceleration of Cassini during six close flybys between 2006 and 2011 have revealed that Titan responds to the variable tidal field exerted by Saturn with periodic changes of its quadrupole gravity, at about 4% of the static value. Two independent determinations of the corresponding degree-2 Love number yield k(2) = 0.589 ± 0.150 and k(2) = 0.637 ± 0.224 (2?). Such a large response to the tidal field requires that Titan's interior be deformable over time scales of the orbital period, in a way that is consistent with a global ocean at depth. PMID:22745254

Iess, Luciano; Jacobson, Robert A; Ducci, Marco; Stevenson, David J; Lunine, Jonathan I; Armstrong, John W; Asmar, Sami W; Racioppa, Paolo; Rappaport, Nicole J; Tortora, Paolo

2012-07-27

175

Estimating Tides from a Planetary Flyby Mission  

NASA Astrophysics Data System (ADS)

Previous and current laser altimeter instruments (e.g. MOLA, NLR, LOLA, MLA) acquired measurements in orbit to provide global topography and study the surface and sub-surface properties of planetary bodies. We show that altimetric data from multiple flybys can make significant contributions to the geophysical understanding of the target body. In particular, the detection of the body tide (e.g. surface deformation due to the tides raised by the Sun or the parent body) and the estimation of its amplitude can yield critical information about the interior structure. We conduct a full simulation of a planetary flyby mission around Europa. We use the GEODYN II program developed and maintained at NASA GSFC to process altimetric and radiometric tracking data created using truth models. The data are processed in short two-day segments (arcs) centered on each closest approach. The initial trajectory is integrated using a priori (truth) models of the planetary ephemeris, the gravity field, the tidal Love numbers k2 and h2 (which describe the amplitudes of the time-variable tidal potential and the time-variable radial deformation respectively). The gravity field is constructed using a Kaula-like power law and scaling considerations from other planetary bodies. The global-scale static topography is also chosen to follow a power law, and higher-resolution local maps consistent with recent stereo-topography work are used to assess the expected variations along altimetric profiles. We assume realistic spacecraft orientation to drive a spacecraft macro-model and model the solar radiation pressure acceleration. Radiometric tracking data are generated from the truth trajectory accounting for geometry (occultations by Europa or Jupiter or the Sun), DSN visibility and scheduling (8h per day) and measurement noise (Ka-band quality, plasma noise). Doppler data have a 10-second integration step while Range data occur every 5 minutes. The altimetric data are generated using realistic instrument performance (frequency, maximum range, measurement noise) and an artificial topographic map of the surface. These simulated data are processed using perturbed initial states, and batched least-squares estimation yield estimated values and uncertainties for selected parameters. Preliminary results with Ka-band radiometric data alone suggest the Love number k2 can be recovered to about 1 percent with this flyby tour trajectory. Altimetric crossovers are to be constructed and used to constrain the deformational tidal Love number h2. The number, and impact, of available crossovers strongly depends on the capability of the laser altimeter, and we quantify how a larger maximum range can contribute to the recovery of the body tide.

Mazarico, Erwan; Genova, Antonio; Smith, David; Zuber, Maria; Sun, Xiaoli

2014-05-01

176

Simulated planetary wave-tide interactions in the atmosphere of Mars  

NASA Astrophysics Data System (ADS)

This study is a first attempt to simulate the nonlinear interactions between planetary waves and tides in the atmosphere of Mars and to examine the consequences of the secondary waves that result from these interactions. Recent analysis of aerobraking densities show clear signatures of secondary waves produced by the modulation of tides by planetary waves. The vertically propagating secondary waves serve to modulate longitudinal density structures (due to nonmigrating tides) at planetary wave periods, even in the local absence of planetary waves. In this parametric study, using a general circulation model of Mars, we determine the most important waves produced by these interactions and quantify their induced variability at aerobraking altitudes.

Moudden, Y.; Forbes, J. M.

2011-01-01

177

Toxic Blooms: Understanding Red Tides  

NSDL National Science Digital Library

This online seminar reviews the topic of red tides in four sessions, which review the effect HABs have on public health, wildlife and the economy; describe common harmful algal species and their toxins; identify poisoning symptoms; compare methods of treatment if poisoned; describe some potential methods to control HABs; and identify research areas where information on HABs is still inadequate. After completing the sessions, an optional knowledge test is provided based on the seminar material.

Anderson, Don; The Woods Hole Oceanographic Institution, Fathom

178

The magnetic tides of Honolulu  

NASA Astrophysics Data System (ADS)

We review and analyse the phenomenon of time-invariant, periodic geomagnetic tides. These are generated by the deterministic physics of the ionospheric and oceanic dynamos, and, to a lesser extent, by the solar-quiet magnetosphere, and they are affected by currents induced in the Earth's electrically conducting interior. Using a long historical time-series of hourly magnetic vector measurements made at the Honolulu observatory, we construct high-resolution, frequency-domain power spectra across periods from 0.1 to 10 000.0 d using maximum-entropy and Lomb periodogram algorithms. Recognizing that harmonics corresponding to fundamental forcing periods can, themselves, have amplitude and phase modulation driven by other forcing harmonics, we identify solar-diurnal tides and their annual and solar-cycle sideband modulations, lunar semidiurnal tides and their solar-diurnal sidebands, and tides due to precession of lunar eccentricity and nodes. In contrast to reports by other investigators, we cannot identify tidal signals that might be related to the 22-yr Hale cycle, the Chandler wobble and the quasi-biennial oscillation. Using a least-squares algorithm to estimate the amplitudes and phases of individual tidal constituents, we construct synthetic model time-series that are representative of geomagnetic tidal variation. The signals summarized in this report can be used to test fundamental understanding of the dynamics of the solar-quiet ionosphere and magnetosphere, the ocean and the electrically conducting interior of the Earth, and they can be used to specify a quiet-time baseline against which magnetospheric storm disturbance can be measured.

Love, Jeffrey J.; Rigler, E. Joshua

2014-06-01

179

Severe Weather  

NSDL National Science Digital Library

Educating the public about safety issues related to severe weather is part of the National Oceanic and Atmospheric Administration's (NOAA) mission. The National Weather Service (NWS)--which is part of NOAA and its parent agency, the Department of Commerce--is charged with the critical responsibility of observing and reporting the weather and with issuing forecasts and warnings of weather and floods in the interest of national safety and economy. Through a massive network of weather-monitoring and reporting stations around the globe, including land, sea, air, and space-borne instruments, NWS scientists constantly assimilate all of the reliable weather data available. Much of this data are then used in numerical computer models of the atmosphere that help to accurately describe and interpret current conditions and produce the best possible forecasts of future weather.

Forde, Evan B.

2004-04-01

180

Influence analysis of Arctic tide gauges using leverages  

NASA Astrophysics Data System (ADS)

Reconstructions of historical sea level in the Arctic Ocean are fraught with difficulties related to lack of data, uneven distribution of tide gauges and seasonal ice cover. Considering the period from 1950 to the present, we attempt to identify conspicuous tide gauges in an automated way, using the statistical leverage of each individual gauge. This may be of help in determining appropriate procedures for data preprocessing, of particular importance for the Arctic area as the GIA is hard to constrain and many gauges are located on rivers. We use a model based on empirical orthogonal functions from a calibration period, in this preliminary case Drakkar ocean model data, which are forced using historical tide gauge data from the PSMSL database. The resulting leverage for each tide gauge may indicate that it represents a distinct mode of variability, or that its time series is perturbed in a way inappropriate for the reconstruction so that it should be removed from the reconstruction model altogether. Therefore, the characteristics of the high-leverage gauges are examined in detail.

Limkilde Svendsen, Peter; Baltazar Andersen, Ole; Aasbjerg Nielsen, Allan

2014-05-01

181

Coastal numerical modelling of tides: Sensitivity to domain size and remotely generated internal tide  

NASA Astrophysics Data System (ADS)

The propagation of remotely generated superinertial internal tides constitutes a difficulty for the modelling of regional ocean tidal variability which we illustrate in several ways. First, the M2 tidal solution inside a control region located along the Southern California Bight coastline is monitored while the extent of the numerical domain is increased (up to 512×512 km). While the amplitude and phase of sea level averaged over the region is quasi-insensitive to domain size, a steady increase of kinetic energy, predominantly baroclinic, is observed with increasing domain size. The increasing flux of energy into the control region suggests that this trend is explained by the growing contribution from remote generation sites of internal tide which can propagate up to the control region. Increasing viscosities confirms this interpretation by lowering baroclinic energy levels and limiting their rate of increase with domain size. Doubling the grid spacing allows consideration of numerical domains 2 times larger. While the coarse grid has lower energy levels than the finer grid, the rate of energy increase with domain size appears to be slowing for the largest domain of the coarse grid simulations. Forcing the smallest domain with depth-varying tidal boundary conditions from the simulation in the largest domain produces energy levels inside the control region comparable to those in the control region for the largest domain, thereby confirming the feasibility of a nested approach. In contrast, simulations forced with a subinertial tidal constituent (K1) show that when the propagation of internal tide is limited, the control region kinetic energy is mostly barotropic and the magnitudes of variations of the kinetic energy with domain size are reduced.

Ponte, Aurelien L.; Cornuelle, Bruce D.

2013-02-01

182

Ocean circulation for the Indonesian seas driven by tides and atmospheric forcings: Comparison to observational data  

NASA Astrophysics Data System (ADS)

A 1/36° high-resolution nested structure ocean model for Indonesian seas that combines atmospheric and tidal forcings (hereafter referred to as IP3-tide) has been developed based on the modified Princeton Ocean Model (POM). Prior to model application, in 2004, we analyzed the IP3-tide by using observational data, derived data, and a global atlas model. A comparison between IP3-tide with 13 tide gauge points and 11 T/P points resulted in 76-92% certainty. Correlation of temperature from scattered depths and points between the model and XBT data reached 97.5% agreement. The modeled velocity successfully captured the low and high frequency variability shown in INSTANT mooring and TAO/TRITON data. Explicit simulation of tidal processes by regional ocean circulation model improved the representation of circulation in the Indonesian seas. At the tidal frequencies, vertical mixing is increased due to the impact of baroclinic tides and horizontal mixing is enhanced by presence of barotropic tidal motion. Enhanced mixing is responsible for eroding the salinity maximum found in the water masses advected from the Pacific Ocean. On the other hand, seasonal variability changes the vertical density structure of water column, which influences the distribution of internal tidal waves. These results demonstrated the importance of explicit tide simulation by regional ocean circulation model for correct presentation of ocean circulation structure and its variability in the Indonesian seas.

Kartadikaria, A. R.; Miyazawa, Y.; Varlamov, S. M.; Nadaoka, K.

2011-09-01

183

Meteor radar observations of short-term variability of quasi 2 day waves and their interaction with tides and planetary waves in the mesosphere-lower thermosphere region over Thumba (8.5°N, 77°E)  

NASA Astrophysics Data System (ADS)

Meteor radar measurements of zonal and meridional winds over a low-latitude station, Thumba (8.5°N, 77°E), during March 2006 to March 2009 are used to study the quasi 2 day wave structure in the mesosphere-lower thermosphere (MLT) region. Emphasis is placed on the study of the day-to-day variations of quasi 2 day waves and their interaction with diurnal tides and planetary waves. The seasonal variation of quasi 2 day waves showed two maxima, one during summer and the other during winter, coinciding with the strong eastward winds in the MLT region along with a distinct peak during the month of October. Subsequent analysis of TIMED/SABER observations during October revealed the presence of a westward propagating quasi 2 day wave with zonal wave number 3 over the present latitude. The seasonal variation of quasi 2 day wave is also discussed with respect to the Stratospheric Semiannual Oscillation (SSAO), and we found that the quasi 2 day wave activity peaks in the MLT region during the phase transition of SSAO as well as during the eastward phase. Wavelet and subsequent bispectral analysis confirmed the wave-wave interactions of quasi 2 day wave and planetary waves with periods of 5-10 and 15-20 days. The 16 h oscillation, which is believed to be generated by interaction of quasi 2 day wave and diurnal tide, showed an excellent correlation with quasi 2 day wave activity. Apart from reporting day-to-day variation of quasi 2 day wave for the first time over this latitude, there are two new results from the present study: (1) a consistent peak in quasi 2 day activity during October, which has never been reported and has been observed for the first time over low latitudes, and (2) the relation between SSAO and quasi 2 day wave activity.

Suresh Babu, Veena; Kishore Kumar, Karanam; John, Sherine R.; Subrahmanyam, K. V.; Ramkumar, Geetha

2011-08-01

184

Predicting Weather  

NSDL National Science Digital Library

By performing the activities presented in this website, fourth grade students can learn about weather instruments and data collection. This website, produced by the Government of Saskatchewan, also explores how the weather can impact local communities. Each activity presented here includes both objectives and assessment techniques for the lesson. Sixteen different activity suggestions provide students and teachers with ample opportunities to explore weather in the classroom.

2008-03-28

185

Weather Experiments  

NSDL National Science Digital Library

Looking for fun ways to learn about weather? Weather Wiz Kids has 39 fun weather related experiments for you to try. These experiments can be done in the classroom with your friends or even at home! Some of the experiments on the site include: tornado in a bottle, make lightning, make it rain, cloud in a bottle, what's in the wind, the Doppler Effect, and baking soda volcano.

2010-01-01

186

Weather Instruments  

NSDL National Science Digital Library

This Topic in Depth discusses the variety of instruments used to collect climate and weather data. The first two websites provide simple introductions to the many weather instruments. Bethune Academy's Weather Center (1) discusses the functions of psychrometers, anemometers, weather balloons, thermometers, and barometers. The Illinois State Water Survey (2) furnishes many images of various instruments that collect data daily for legal issues, farmers, educators, students, and researchers. The third website (3), created by the Center for Improving Engineering and Science Education (CIESE), provides a classroom activity to educate users on how to build and use weather instruments. By the end of the group project, students should know all about wind vanes, rain gauges, anemometers, and thermometers. Next, the Miami Museum of Science provides a variety of activities to help students learn about the many weather instruments including wind scales and wind chimes (4). Students can learn about the wind, air pressure, moisture, and temperature. At the fifth website, the Tyson Research Center at Washington University describes the devices it uses in its research (5). At the various links, users can find out the center's many projects that utilize meteorological data such as acid rain monitoring. The sixth website, a pdf document created by Dr. John Guyton at the Mississippi State University Extension Service, provides guidance to teachers about the education of weather patterns and instruments (6). Users can find helpful information on pressure systems, humidity, cloud patterns, and much more. Next, the University of Richmond discusses the tools meteorologists use to learn about the weather (7). While providing materials about the basic tools discussed in the other websites, this site also offers information about weather satellites, radar, and computer models. After discovering the many weather instruments, users can learn about weather data output and analysis at the Next Generation Weather Lab website (8). This expansive website provides an abundance of surface data and upper air data as well as satellite and radar images for the United States.

187

The far-reaching back-effect of coastal tides upon open-ocean tides  

Microsoft Academic Search

As part of a study into various factors that impact the amplitudes of semidiurnal tides in the open and coastal ocean, we investigate the back-effect of coastal tides upon open-ocean tides. We use two tools for our study--a forward numerical model of the global ocean tides, and analytical solutions for a damped\\/driven non-rotating one-dimensional deep ocean basin of uniform depth

B. K. Arbic; C. Garrett; R. H. Karsten

2008-01-01

188

Weather Forecasting  

NSDL National Science Digital Library

This activity (on page 2 of the PDF) is a full inquiry investigation into meteorology and forecasting. Learners will research weather folklore, specifically looking for old-fashioned ways of predicting the weather. Then, they'll record observations of these predictors along with readings from their own homemade barometer, graphing the correct predictions for analysis. Relates to linked video, DragonflyTV: Forecasting.

Twin Cities Public Television, Inc.

2005-01-01

189

Space Weather  

E-print Network

Space Weather :: Printer Friendly Version of Article 2004SW000119 http://www.agu magnetic Faraday cages, to designing artificial magnetospheres around the spacecraft, to employing into nature. Louis J. Lanzerotti is Editor of Space Weather, Distinguished Research Professor at the New

Shepherd, Simon

190

Wacky Weather  

ERIC Educational Resources Information Center

What do a leaf blower, water hose, fan, and ice cubes have in common? Ask the students who participated in an integrative science, technology, engineering, and mathematics (I-STEM) education unit, "Wacky Weather," and they will tell say "fun and severe weather"--words one might not have expected! The purpose of the unit…

Sabarre, Amy; Gulino, Jacqueline

2013-01-01

191

Tides and Trends in Higher Education.  

ERIC Educational Resources Information Center

This paper examines changes in American higher education, using the metaphor of ocean tides. The tides of change in the 1980s included public demands for assessment and accountability; fairness and credibility in advantages and benefits; improved quality of education; effectiveness and efficiency; assurance that college graduates were personally…

Fincher, Cameron

192

Internal tide radiation from the Luzon Strait  

NASA Astrophysics Data System (ADS)

M2, K1, and O1 internal tides originating in the Luzon Strait are investigated using the sea surface height measurements by multiple satellites ERS-2, Envisat, TOPEX/Poseidon, Jason-1/2, and Geosat Follow-On. A plane wave fit method is used to resolve multiple internal tides in arbitrary horizontal directions. The Luzon Strait is an energetic internal tide generation site, and radiates internal tides both westward into the South China Sea (SCS) and eastward into the western Pacific (WP). In the SCS, the K1 and O1 internal tides propagate over 1600 km, reaching the Vietnam coast; in the WP, they propagate over 2500 km and arrive to the Mariana Ridge and Guam. The K1 and O1 internal tides refract toward the Equator during propagation. The M2 internal tides in the SCS bifurcate into two beams. The northwestward beam is coincident with the frequent occurrence of internal solitary waves in this region, implying their causative relation. The phase speeds inferred from the altimetric along-beam propagation agree with the theoretical values. Due to the influence of the Earth's rotation, the K1 and O1 phase speeds decrease remarkably from high to low latitudes. For the diurnal internal tides, the eastward radiation is about 50% greater than the westward radiation. For M2, the westward radiation is about two times the eastward radiation. The altimetric energy fluxes are about 50% of those in numerical model simulations.

Zhao, Zhongxiang

2014-08-01

193

Resonance of Infragravity Waves With Ocean Tides ?  

Microsoft Academic Search

How and where the ocean tides dissipate the energy are longstanding questions whose answers would bear on consequences ranging from the history of the Moon to the climate changes. Historically, there are two principal mechanisms of the sink of tidal energy. One is the bottom friction in shallow seas and the other is topographic scattering of surface tides into internal

H. Sugioka; Y. Fukao; D. Suetsugu; H. Shiobara; T. Kanazawa

2008-01-01

194

WEATHER ON OTHER WORLDS. I. DETECTION OF PERIODIC VARIABILITY IN THE L3 DWARF DENIS-P J1058.7-1548 WITH PRECISE MULTI-WAVELENGTH PHOTOMETRY  

SciTech Connect

Photometric monitoring from warm Spitzer reveals that the L3 dwarf DENIS-P J1058.7-1548 varies sinusoidally in brightness with a period of 4.25{sup +0.26}{sub -0.16} hr and an amplitude of 0.388% {+-} 0.043% (peak-to-valley) in the 3.6 {mu}m band, confirming the reality of a 4.31 {+-} 0.31 hr periodicity detected in J-band photometry from the SOAR telescope. The J-band variations are a factor of 2.17 {+-} 0.35 larger in amplitude than those at 3.6 {mu}m, while 4.5 {mu}m Spitzer observations yield a 4.5 {mu}m/3.6 {mu}m amplitude ratio of only 0.23 {+-} 0.15, consistent with zero 4.5 {mu}m variability. This wide range in amplitudes indicates rotationally modulated variability due to magnetic phenomena and/or inhomogeneous cloud cover. Weak H{alpha} emission indicates some magnetic activity, but it is difficult to explain the observed amplitudes by magnetic phenomena unless they are combined with cloud inhomogeneities (which might have a magnetic cause). However, inhomogeneous cloud cover alone can explain all our observations, and our data align with theory in requiring that the regions with the thickest clouds also have the lowest effective temperature. Combined with published vsin (i) results, our rotation period yields a 95% confidence lower limit of R{sub *} {>=} 0.111 R{sub Sun }, suggesting upper limits of 320 Myr and 0.055 M{sub Sun} on the age and mass. These limits should be regarded cautiously because of {approx}3{sigma} inconsistencies with other data; however, a lower limit of 45 Degree-Sign on the inclination is more secure. DENIS-P J1058.7-1548 is only the first of nearly two dozen low-amplitude variables discovered and analyzed by the Weather on Other Worlds project.

Heinze, Aren N.; Metchev, Stanimir [Department of Physics and Astronomy, State University of New York, Stony Brook, NY 11794-3800 (United States); Apai, Daniel; Flateau, Davin [University of Arizona Department of Astronomy, 933 N. Cherry Avenue, Tucson, AZ 85721 (United States); Kurtev, Radostin [Departamento de Fisica y Astronomia, Facultad de Ciencias, Universidad de Valparaiso, Av. Gran Bretana 1111, Casilla 5030, Valparaiso (Chile); Marley, Mark [NASA Ames Research Center, MS-245-3, Moffett Field, CA 94035 (United States); Radigan, Jacqueline [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4 (Canada); Burgasser, Adam J. [University of California San Diego, Center for Astrophysics and Space Science, 9500 Gilman Drive, Mail Code 0424, La Jolla, CA 92093 (United States); Artigau, Etienne [Departement de Physique and Observatoire du Mont Megantic, Universite de Montreal, C.P. 6128, Succ. Centre-Ville, Montreal, QC, H3C 3J7 (Canada); Plavchan, Peter, E-mail: aren.heinze@stonybrook.edu, E-mail: stanimir.metchev@stonybrook.edu [NASA Exoplanet Science Institute, California Institute of Technology, M/C 100-22, 770 South Wilson Avenue, Pasadena, CA 91125 (United States)

2013-04-20

195

Weather, Climate, and You.  

ERIC Educational Resources Information Center

Information from the American Institute of Medical Climatologists on human responses to weather and climatic conditions, including clouds, winds, humidity, barometric pressure, heat, cold, and other variables that may exert a pervasive impact on health, behavior, disposition, and the level of efficiency with which individuals function is reviewed.…

Blai, Boris, Jr.

196

Weather Forecasting  

NSDL National Science Digital Library

Weather Forecasting is a set of computer-based learning modules that teach students about meteorology from the point of view of learning how to forecast the weather. The modules were designed as the primary teaching resource for a seminar course on weather forecasting at the introductory college level (originally METR 151, later ATMO 151) and can also be used in the laboratory component of an introductory atmospheric science course. The modules assume no prior meteorological knowledge. In addition to text and graphics, the modules include interactive questions and answers designed to reinforce student learning. The module topics are: 1. How to Access Weather Data, 2. How to Read Hourly Weather Observations, 3. The National Collegiate Weather Forecasting Contest, 4. Radiation and the Diurnal Heating Cycle, 5. Factors Affecting Temperature: Clouds and Moisture, 6. Factors Affecting Temperature: Wind and Mixing, 7. Air Masses and Fronts, 8. Forces in the Atmosphere, 9. Air Pressure, Temperature, and Height, 10. Winds and Pressure, 11. The Forecasting Process, 12. Sounding Diagrams, 13. Upper Air Maps, 14. Satellite Imagery, 15. Radar Imagery, 16. Numerical Weather Prediction, 17. NWS Forecast Models, 18. Sources of Model Error, 19. Sea Breezes, Land Breezes, and Coastal Fronts, 20. Soundings, Clouds, and Convection, 21. Snow Forecasting.

Nielsen-Gammon, John

1996-09-01

197

Planetary Weather  

NSDL National Science Digital Library

This lesson plan is part of the DiscoverySchool.com lesson plan library for grades 6-8. It focuses on the weather conditions on other planets. After learning more about weather patterns, students research the weather on a given planet and create a visual display of the conditions there. It includes objectives, materials, procedures, discussion questions, evaluation ideas, suggested readings, and vocabulary. There are videos available to order which complement this lesson, and links to teaching tools for making custom quizzes, worksheets, puzzles and lesson plans.

198

Bottom Pressure Tides Along a Line in the Southeast Atlantic Ocean and Comparisons with Satellite Altimetry  

NASA Technical Reports Server (NTRS)

Seafloor pressure records, collected at 11 stations aligned along a single ground track of the Topex/Poseidon and Jason satellites, are analyzed for their tidal content. With very low background noise levels and approximately 27 months of high-quality records, tidal constituents can be estimated with unusually high precision. This includes many high-frequency lines up through the seventh-diurnal band. The station deployment provides a unique opportunity to compare with tides estimated from satellite altimetry, point by point along the satellite track, in a region of moderately high mesoscale variability. That variability can significantly corrupt altimeter-based tide estimates, even with 17 years of data. A method to improve the along-track altimeter estimates by correcting the data for nontidal variability is found to yield much better agreement with the bottom-pressure data. The technique should prove useful in certain demanding applications, such as altimetric studies of internal tides.

Ray, Richard D.; Byrne, Deidre A.

2010-01-01

199

Impact of tidal density variability on orbital and reentry predictions  

NASA Astrophysics Data System (ADS)

Since the first satellites entered Earth orbit in the late 1950's and early 1960's, the influences of solar and geomagnetic variability on the satellite drag environment have been studied, and parameterized in empirical density models with increasing sophistication. However, only within the past 5 years has the realization emerged that "troposphere weather" contributes significantly to the "space weather" of the thermosphere, especially during solar minimum conditions. Much of the attendant variability is attributable to upward-propagating solar tides excited by latent heating due to deep tropical convection, and solar radiation absorption primarily by water vapor and ozone in the stratosphere and mesosphere, respectively. We know that this tidal spectrum significantly modifies the orbital (>200 km) and reentry (60-150 km) drag environments, and that these tidal components induce longitude variability not yet emulated in empirical density models. Yet, current requirements for improvements in orbital prediction make clear that further refinements to density models are needed. In this paper, the operational consequences of longitude-dependent tides are quantitatively assessed through a series of orbital and reentry predictions. We find that in-track prediction differences incurred by tidal effects are typically of order 200 ± 100 m for satellites in 400-km circular orbits and 15 ± 10 km for satellites in 200-km circular orbits for a 24-hour prediction. For an initial 200-km circular orbit, surface impact differences of order 15° ± 15° latitude are incurred. For operational problems with similar accuracy needs, a density model that includes a climatological representation of longitude-dependent tides should significantly reduce errors due to this source.

Leonard, J. M.; Forbes, J. M.; Born, G. H.

2012-12-01

200

Weatherizing America  

ScienceCinema

As Recovery Act money arrives to expand home weatherization programs across the country, Zachary Stewart of Phoenix, Ariz., and others have found an exciting opportunity not only to start working again, but also to find a calling.

Stewart, Zachary; Bergeron, T.J.; Barth, Dale; Qualis, Xavier; Sewall, Travis; Fransen, Richard; Gill, Tony;

2013-05-29

201

Weather One  

NSDL National Science Digital Library

This website contains summaries and lessons about various aspects of weather. This includes the seasons, types of clouds, air, winds, global warming, hurricanes, tornadoes and lightning. Worksheets are provided to accompany the lesson themes.

Friend, Duane

202

Winter Weather  

MedlinePLUS

... During a Wildfire Responders Wildfire Smoke After a Fire Worker Safety During Fire Cleanup Wildfires PSAs Related Links Winter Weather Extreme ... at Disaster Sites Preventing Chain Saw Injuries During Tree Removal Electrical Safety and Generators Handling Human Remains ...

203

Weather Creator  

NSDL National Science Digital Library

This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What can you do to make it rain or even snow? 4. Does it always snow when ...

Kshumway

2009-09-28

204

Exploring Weather  

NSDL National Science Digital Library

Second Grade Standard 3: Students will develop an understanding of their environment. Objective 2: Observe and describe weather. Indicator a: Observe and describe patterns of change in weather. Monday, February 1st: Look at the five-day forecast for Salt Lake City, Utah at Five day forecasts. The high temperature for the day will be in red and the low temperature will be in blue. Make sure you look at the temperature listed in degrees Farenheit (F) not degrees Celcius (C). Make ...

Emily, Miss

2010-01-29

205

Weather Maps  

NSDL National Science Digital Library

This lesson plan is part of the DiscoverySchool.com lesson plan library for grades K-5. It focuses on basic information about the weather and how different weather maps depict conditions. Included are objectives, materials, procedures, discussion questions, evaluation ideas, suggested readings, and vocabulary. There are videos available to order which complement this lesson, and links to teaching tools for making custom quizzes, worksheets, puzzles and lesson plans.

206

A theory of ionospheric response to upward-propagating tides: Electrodynamic effects and tidal mixing effects  

NASA Astrophysics Data System (ADS)

The atmospheric tide at ionospheric heights is composed of those locally generated and those propagated from below. The role of the latter in producing the variability of the daytime ionosphere is examined using the National Center for Atmospheric Research Thermosphere-Ionosphere-Electrodynamics General Circulation Model. The impact of upward-propagating tides is evaluated by running simulations with and without tidal forcing at the lower boundary (approximately 96 km), which imitates the effect of tides from below. When migrating diurnal and semidiurnal tides at the lower boundary is switched on, the intensity of E region currents and the upward velocity of the equatorial F region vertical plasma drift rapidly increase. The low-latitude ionospheric total electron content (TEC) first increases, then gradually decreases to below the initial level. The initial increase in the low-latitude TEC is caused by an enhanced equatorial plasma fountain while the subsequent decrease is due to changes in the neutral composition, which are characterized by a global-scale reduction in the mass mixing ratio of atomic oxygen O1. The results of further numerical experiments indicate that the mean meridional circulation induced by dissipating tides in the lower thermosphere is mainly responsible for the O1 reduction; it acts like an additional turbulent eddy and produces a "mixing effect" that enhances net downward transport and loss of O1. It is stressed that both electrodynamic effects and mixing effects of upward-propagating tides can be important in producing the variability of ionospheric plasma density. Since the two mechanisms act in different ways on different time scales, the response of the actual ionosphere to highly variable upward-propagating tides is expected to be complex.

Yamazaki, Yosuke; Richmond, Arthur D.

2013-09-01

207

Tides, the PIG, and "warm" water  

NASA Astrophysics Data System (ADS)

The present rapid melting of the Pine Island Glacier (PIG) has been attributed to basal melting driven by the ocean. Specifically, this ocean melting is attributed to currents and tides pumping "warm" Circumpolar Deep Water (CDW) into the ice shelf cavity. To identify tidal activity in the region, an observational time series of yo-yo CTD (Conductivity, Temperature, and Depth) data collected in the PIG outflow region was analyzed. The water column in front of the PIG consisted of two primary layers, a meltwater layer exiting the ice shelf cavity over a layer of CDW. Semidiurnal tides were present in both layers, with both the strength and direction of the tides differing between the two layers. The upper layer tides were stronger and directed in and out of the cavity, while the lower layer tides were primarily directed along the front of the cavity. Energy was found to be transferred from the semidiurnal tide to other frequencies and to be reflected by the ice shelf front. These mechanisms were most prominent at the interfaces between layers and indicate potential mixing between the layers. In conclusion, tides were found to contribute to the circulation into the ice shelf cavity and also to mixing of the exiting water, which influences pumping of the CDW into the ice shelf cavity and melting of the PIG.

Robertson, Robin

2010-08-01

208

Dissipation and Synchronization due to Creeping Tides.  

NASA Astrophysics Data System (ADS)

We present a new reophysical theory of the dynamical tides of celestial bodies. It is founded on a Newtonian creep instead of the classical delayed elastic approach of the standard viscoelastic theories. All results of the theory derive from the solution of a non-homogeneous ordinary differential equation and lags appear as a natural outcome from the solution of the equation and are not external ad hoc quantities plugged in an elastic model. The lag due to the Newtonian creep is proportional to the tide frequency (as in Darwin’s original theory), and is necessarily small. The amplitudes depend on the viscosity of the body and on the frequency of the tide. As a consequence, the so-called pseudo-synchronous rotation has an excess velocity roughly proportional to 6ne2/(?2+1/?2) (? is the tide frequency in units of a relaxation factor inversely proportional to the viscosity) instead of the exact 6ne2 of standard theories. The dissipation is inversely proportional to (? + 1/?) thus, in the inviscid limit it is roughly proportional to the frequency (as in standard theories), but that behavior is inverted when the viscosity is high and the response factor much smaller than the tide frequency. When the viscosity is high, however, the creeping tide fails to reproduce the actual geometric tide and, to reconcile theory and observation, we need to assume the coexistence of a small elastic tide superposed to the creeping tide. The theory is applied to several Solar System and extrasolar bodies and the values of the relaxation factor ? (and its current correspondent Q) are derived for these bodies on the basis of currently available data.

Ferraz-Mello, Sylvio

2012-05-01

209

Investigation on empirical estimation of minor tides  

NASA Astrophysics Data System (ADS)

In general recent global ocean tide models provide tidal constants for the most dominant semi-diurnal, diurnal, selected shallow water and some long period tides, typically M2, N2, N2 , K2, 2N2, O1 , P1 , Q1 , K1, S1, M4, Mf and Mm. Contributions of minor tidal terms and modulations of the main terms are in general considered by inferring admittance assumptions and nodal corrections. The rather new hydrodynamic model FES2012 extends this list and now provides additional tables for tidal constants for some 18 complementary minor tides. We investigate here if the long time series of precise multi-mission altimeter data (e.g. on the repeated ground tracks of TOPEX/Jason1/Jason2) allows a robust empirical estimation of those minor tides which appear to be (after the major tides listed above) the next dominant tidal waves. Candidate minor tidal waves are M1, J1, ?1, ?2, L2, T2, ?2. Can these partial tides empirically separated from tides with adjacent frequencies (e.g. ?2 versus 2N2 or T2 versus S2)? How do the tidal constant for those minor tides compare with those of the hydrodynamic model FES2012? What are the quantitative differences between applying admittance theory and using the tidal constants derived empirically? These investigations are performed in the context of the SPOT-project, aiming to improve the transfer function from ocean tide angular momentum to Earth rotation parameters, the variations of polar motion and LOD.

Bosch, Wolfgang; Madzak, Matthias; Hagedorn, Jan; Schuh, Harald; Böhm, Sigrid

2014-05-01

210

Possible forcing of global temperature by the oceanic tides  

PubMed Central

An approximately decadal periodicity in surface air temperature is discernable in global observations from A.D. 1855 to 1900 and since A.D. 1945, but with a periodicity of only about 6 years during the intervening period. Changes in solar irradiance related to the sunspot cycle have been proposed to account for the former, but cannot account for the latter. To explain both by a single mechanism, we propose that extreme oceanic tides may produce changes in sea surface temperature at repeat periods, which alternate between approximately one-third and one-half of the lunar nodal cycle of 18.6 years. These alternations, recurring at nearly 90-year intervals, reflect varying slight degrees of misalignment and departures from the closest approach of the Earth with the Moon and Sun at times of extreme tide raising forces. Strong forcing, consistent with observed temperature periodicities, occurred at 9-year intervals close to perihelion (solar perigee) for several decades centered on A.D. 1881 and 1974, but at 6-year intervals for several decades centered on A.D. 1923. As a physical explanation for tidal forcing of temperature we propose that the dissipation of extreme tides increases vertical mixing of sea water, thereby causing episodic cooling near the sea surface. If this mechanism correctly explains near-decadal temperature periodicities, it may also apply to variability in temperature and climate on other times-scales, even millennial and longer. PMID:11607740

Keeling, Charles D.; Whorf, Timothy P.

1997-01-01

211

Diurnal tides in the Arctic Ocean  

NASA Technical Reports Server (NTRS)

A 2D numerical model with a space grid of about 14 km is applied to calculate diurnal tidal constituents K(1) and O(1) in the Arctic Ocean. Calculated corange and cotidal charts show that along the continental slope, local regions of increased sea level amplitude, highly variable phase and enhanced currents occur. It is shown that in these local regions, shelf waves (topographic waves) of tidal origin are generated. In the Arctic Ocean and Northern Atlantic Ocean more than 30 regions of enhanced currents are identified. To prove the near-resonant interaction of the diurnal tides with the local bottom topography, the natural periods of oscillations for all regions have been calculated. The flux of energy averaged over the tidal period depicts the gyres of semitrapped energy, suggesting that the shelf waves are partially trapped over the irregularities of the bottom topography. It is shown that the occurrence of near-resonance phenomenon changes the energy flow in the tidal waves. First, the flux of energy from the astronomical sources is amplified in the shelf wave regions, and afterwards the tidal energy is strongly dissipated in the same regions.

Kowalik, Z.; Proshutinsky, A. Y.

1993-01-01

212

Ocean Tide and Waves Beneath the Ross Ice Shelf, Antarctica  

Microsoft Academic Search

The ocean tide in the southern Ross Sea is principally diurnal. The tropic tide range (double amplitude) is between 1 and 2 meters, depending on the location, and is closely related to the local water-layer thickness. The range of the tropic tide is more than three times the range of the equatorial tide. Cotidal and coamplitude charts were made for

Richard T. Williams; Edwin S. Robinson

1979-01-01

213

THE EARTH TIDE EFFECTS ON PETROLEUM RESERVOIRS Preliminary Study  

E-print Network

THE EARTH TIDE EFFECTS ON PETROLEUM RESERVOIRS Preliminary Study A THESIS SUBMITTED ON THE STRESS-STRAIN THEORY AND THE EARTH TIDE MECHANISM 4 2.1 Stress-Strain Theory 4 2.2 General Information on Tides 14 3. THE EFFECTS OF EARTH TIDES ON OPEN WELL-AQUIFER SYSTEMS: STATE OF THE ART 22 3.1 Static

Stanford University

214

Analysis of migrating diurnal tides detected in FORMOSAT-3/COSMIC temperature data  

NASA Astrophysics Data System (ADS)

The characteristics of atmospheric tides in the upper troposphere and lower stratosphere region are investigated using radio occultation (RO) measurements performed by the Formosa Satellite Mission-3/Constellation Observing System for Meteorology, Ionosphere, and Climate (FORMOSAT-3/COSMIC) satellite constellation and compared to tides observed in short-term forecast model fields of European Centre for Medium-Range Weather Forecasts (ECMWF) and National Centers for Environmental Prediction (NCEP). Spectral analysis of 2 years of monthly data (2007 to 2008) yields the migrating diurnal tide to be the largest spectral component. This diurnal tide shows similar temporal, latitudinal, and altitudinal characteristics in all data sets equatorward of 50°. Beyond 50°, COSMIC local time sampling is insufficient within 1 month, which prevents space-time spectral analysis from isolating atmospheric waves. Diurnal tides of temperature are characterized by largest amplitudes in the tropics (0.8 K to 1.0 K at an altitude of 30 km). Amplitudes of diurnal tides analyzed in model data are more pronounced by ˜20%. An annual cycle of the amplitudes, characteristically linked to the movement of the intertropical convergence zone, is clearly revealed. Tropical diurnal phase features downward progression of waves fronts with a vertical wavelength of 20 km. Extratropical diurnal tides are most pronounced in the model data sets with amplitudes of up to 0.5 K at 30 km. In this analysis we also see the influence of high-altitude initialization of RO data by background information in using data processed by two different centers (University Corporation for Atmospheric Research (UCAR) and Wegener Center (WEGC)). UCAR data, initialized by a climatology without tidal information, exhibit no appreciable extratropical diurnal tides, while WEGC data, initialized by ECMWF forecasts, show more pronounced ones. Overall the results underpin the utility of the local-time resolving COSMIC RO constellation data for monitoring diurnal tide dynamics in the stratosphere. The agreement between observational and model data further confirms that the tidal dynamics is appropriately captured in the models, which is important for other (middle/upper) atmosphere models relying on ECMWF or NCEP dynamics.

Pirscher, B.; Foelsche, U.; Borsche, M.; Kirchengast, G.; Kuo, Y.-H.

2010-07-01

215

Sea anemone exposed at low tide  

NSDL National Science Digital Library

Sea anemones are sensitive to drying out. To avoid drying out during low tide and periods of intense sunlight, the anemones roll up to keep their tentacles moist. The outer body of the anemone is thick and tolerant of heat.

Katie Hale (California State University, Fullerton;Student, Biological Sciences)

2007-01-05

216

Tides at the Battery, New York  

NSDL National Science Digital Library

In this exercise, students use online data, spreadsheets, and graphs to analyze tidal fluctuations at the Battery in New York. They will be asked to examine and compare the observed and predicted tides, and then make their own predictions.

Burrows, Charles

217

Internal tide generation by tall ocean ridges  

E-print Network

Internal tides are internal waves of tidal period generated by tidal currents flowing over submarine topography. Tall ridges that are nominally two-dimensional (2-D) are sites of particularly strong generation. The subsequent ...

Echeverri Mondragón, Paula

2009-01-01

218

Geodetic Fixing of Tide Gauge Bench Marks.  

National Technical Information Service (NTIS)

Under the auspices of the International Association for Physical Sciences of the Ocean (IAPSO) a committee was established to identify the oceanographic and geophysical requirements for fixing Tide Gauge Bench Marks (TGBM's) in an absolute terrestrial coo...

W. E. Carter, D. G. Aubrey, T. Baker, C. Boucher, C. LeProvost

1989-01-01

219

Investigations in Marine Chemistry: Tide Pool Ecology.  

ERIC Educational Resources Information Center

Students investigated the salinity of tide pools at different levels in the intertidal zone. Data are analyzed collectively. Students graphed and discussed data. Included are suggestions for evaluation and further study. (Author)

Schlenker, Richard M.

220

Myocardial infarction and weather.  

PubMed

The association of meterological factors with acute myocardial infarction was studied within a one-year period in Helsinki. Seasonal variation was found with the lowest incidence in summer and the highest in late autumn. Environmental temperature was not significantly correlated with the incidence of myocardial infarction but the case fatality rate was higher on coldest days. Atmospheric pressure turned out to be the meteorological variable with the highest correlation with the occurrence of myocardial infarction. Rapid decrease in atmospheric pressure was also associated with increased incidence of acute myocardial infarction. Relative humidity had little independent effect. The weather types with highest and lowest risk of heart attack were determined by the combined use of factor and cluster analysis. The most unfavourable turned out to be a relatively cold and moist weather with low atmospheric pressure, common in Helsinki during early winter and late autumn. The incidence of infarction did not increase on typical cold and dry winter days. The most favourable weather was warm, dry and stable summer weather. The difference in incidences between most and least favourable weather types was three-fold. PMID:616207

Sarna, S; Romo, M; Siltanen, P

1977-08-01

221

Weather from the Stratosphere?  

NASA Technical Reports Server (NTRS)

Is the stratosphere, the atmospheric layer between about 10 and 50 km, important for predicting changes in weather and climate? The traditional view is that the stratosphere is a passive recipient of energy and waves from weather systems in the underlying troposphere, but recent evidence suggests otherwise. At a workshop in Whistler, British Columbia (1), scientists met to discuss how the stratosphere responds to forcing from below, initiating feedback processes that in turn alter weather patterns in the troposphere. The lowest layer of the atmosphere, the troposphere, is highly dynamic and rich in water vapor, clouds, and weather. The stratosphere above it is less dense and less turbulent (see the figure). Variability in the stratosphere is dominated by hemispheric-scale changes in airflow on time scales of a week to several months. Occasionally, however, stratospheric air flow changes dramatically within just a day or two, with large-scale jumps in temperature of 20 K or more. The troposphere influences the stratosphere mainly through atmospheric waves that propagate upward. Recent evidence shows that the stratosphere organizes this chaotic wave forcing from below to create long-lived changes in the stratospheric circulation. These stratospheric changes can feed back to affect weather and climate in the troposphere.

Baldwin, Mark P.; Thompson, David W. J.; Shuckburgh, Emily F.; Norton, Warwick A.; Gillett, Nathan P.

2006-01-01

222

Weather Forecasting  

NSDL National Science Digital Library

Weather Forecasting is one of several online guides produced by the Weather World 2010 project at the University of Illinois. These guides use multimedia technology and the dynamic capabilities of the web to incorporate text, colorful diagrams, animations, computer simulations, audio, and video to introduce topics and concepts in the atmospheric sciences. This module introduces forecast methods and the numerous factors one must consider when attempting to make an accurate forecast. Sections include forecasting methods for different scenarios, surface features affecting forecasting, forecasting temperatures for day and night, and factors for forecasting precipitation.

2010-01-01

223

Wild Weather  

NSDL National Science Digital Library

In this online, interactive module, students learn about severe weather (thunderstorms, hurricanes, tornadoes, and blizzards) and the key features for each type of "wild weather" using satellite images. The module is part of an online course for grades 7-12 in satellite meteorology, which includes 10 interactive modules. The site also includes lesson plans developed by teachers and links to related resources. Each module is designed to serve as a stand-alone lesson, however, a sequential approach is recommended. Designed to challenge students through the end of 12th grade, middle school teachers and students may choose to skim or skip a few sections.

224

Wonderful Weather  

NSDL National Science Digital Library

Second Grade Standard 3: Students will develop an understanding of their environment. Objective 2: Observe and describe weather. Indicator a: Observe and describe patterns of change in weather. Monday November 6th: Look at the five-day forecast for Logan Utah at Five Day Forecast in Utah. The high temperature for the day will be in red and the low temperature will be in blue. Look at the temperature listed in degrees Farenheit (F) not degrees Celcius (C). Make a bar graph for the ...

Broadhead, Ms.

2007-11-06

225

Space Weather  

NSDL National Science Digital Library

With three levels to choose from on each page - beginner, intermediate or advanced - this site provides information on Space Weather and the terms scientists use to describe the everchanging conditions in space. Explosions on the Sun create storms of radiation, fluctuating magnetic fields, and swarms of energetic particles. These phenomena travel outward through the Solar System with the solar wind. Upon arrival at Earth, they interact in complex ways with Earth's magnetic field, creating Earth's radiation belts and the Aurora. Some space weather storms can damage satellites, disable electric power grids, and disrupt cell phone communications systems. This site provides images, activities, and interesting facts about all of these events.

2004-02-06

226

Unisys Weather  

NSDL National Science Digital Library

The Unisys weather website offers a host of weather analyses and forecasts. In the Analyses link, visitors can find satellite images as well as surface, upper air, and radar images. Visitors can learn the intricacies of Unisys's many forecast models such as the Nested Grid Model (NGM), Aviation Model, and the Rapid Update Cycle (RUC) Model. Users can find archived hurricane data for the Atlantic, the Eastern Pacific, and the Western Pacific. The site also furnishes archived surface maps, infrared satellite images, upper air charts, and sea surface temperature (SST) plots.

227

Asymmetric tide in Lake Vallunden (Spitsbergen)  

NASA Astrophysics Data System (ADS)

We observed strongly asymmetric tide in a channel connecting the Van Mijen Fjord and Lake Vallunden in Spitsbergen. The channel is approximately 100 m long, 10 m wide, and 1-2 m deep. Asymmetric tide was also observed in the lake. The form of the semidiurnal tide is described by a combination of only three harmonics (M2, S2 and M4) with different amplitudes and phases. The flood dominant form of the surface elevation in the channel (unlike the ebb dominant tide in the fjord) is formed over a horizontal distance of 50 m over a shallow bottom at the entrance to the channel. The tide in shallow places becomes asymmetric due to nonlinear effects caused by the influence of the bottom and especially by choking of the tidal flow over a sill that is located between the fjord and channel. We think that such a small distance, over which the form of the tide changes, is caused by the small scale of the channel related to the fjord. We suggest a numerical model related to these measurements.

Marchenko, A. V.; Morozov, E. G.

2013-11-01

228

QBO Generated Inter-annual Variations of the Diurnal Tide in the Mesosphere  

NASA Technical Reports Server (NTRS)

We report results from a study with the Numerical Spectral Model (NSM), which produces in the mesosphere significant inter-annual variations in the diurnal tide. Applying Hines Doppler Spread Parameterization (DPS), small-scale gravity waves (GW) drive the Quasi-biennial Oscillation (QBO) and Semi-annual Oscillation (SAO). With a GW source that peaks at the equator and is taken to be isotropic and independent of season, the NSM generates near the equator a QBO with variable periods around 27 months and zonal wind amplitudes close to 20 m / s at 30 Ism. As reported earlier, the NSM reproduces the observed equinoctial maxima in the diurnal tide at altitudes around 95 km. In the present paper it is shown that the QBO modulates the tide such that the seasonal amplitude maxima can vary from one year to another by as much as 30%. Since the period of the QBO is variable, its phase relative to the seasonal cycle changes. The magnitude of the QBO modulation of the tide thus varies considerably as our long-term model simulation shows. To shed light on the underlying mechanism, the relative importance of the linearized advection terms are discussed that involve the meridional and vertical winds of the diurnal tide.

Mayr, Hans G.; Mengel, John G.

2004-01-01

229

Weathering Experiments  

NSDL National Science Digital Library

This experiment is designed to allow students to observe and understand chemical and physical weathering of simulated "rocks". They will place the materials in plastic bags, one wet and one dry, and store them for 3-4 days. At the end of the storage period, they will observe the contents of both bags and answer some questions about what they see.

230

Weather control  

Microsoft Academic Search

Weather modification, the intentional altering of atmospheric conditions to suit the purposes of humankind, has five basic forms: (1) fog dissipation; (2) rain and snow enhancement; (3) hail suppression; (4) lightning suppression; and (5) the abatement of severe storms such as hurricanes and tornadoes. The dissipation of fog and the seeding of clouds with dry ice or silver iodide to

Leepson

1980-01-01

231

Wonderful Weather  

NSDL National Science Digital Library

In this activity, learners conduct three experiments to examine temperature, the different stages of the water cycle, and how convection creates wind. These activities can be used individually or as a group for a lesson on weather. Note: boiling water is required for this activity; adult supervision required.

Workshop, Mission S.

2013-01-01

232

Weather Stations  

NSDL National Science Digital Library

This is a series of seven brief activities about Jupiter's atmosphere and weather. Learners will look at Jupiter's distinct banded appearance, violent storms, and clouds of many different colors. The activities are part of Explore! Jupiter's Family Secrets, a series designed to engage children in space and planetary science in libraries and informal learning environments.

233

The Weather Doctor  

NSDL National Science Digital Library

Published by Spectrum Educational Enterprises, The Weather Doctor Web site is maintained by meteorologist Keith Heidorn. Visitors to the site will find everything from the joys of weather watching, to making rain, to weather history, to much more. Coming from someone who clearly enjoys what they do, this site explores unique aspects of weather including weather people, weather history, and weather and arts.

Heidorn, Keith.

2002-01-01

234

Wind Forcing of the North Sea Pole Tide  

NASA Technical Reports Server (NTRS)

The Chandler wobble of the earth's rotation has a period near 14 months and sets up the 0.5 cm amplitude pole tide in the deep oceans, However, the pole tide is anomalously large in the North Sea, where the amplitude increases sharply up to 3 cm along the continental coast. It is shown here that the sea levels are well correlated with winds at the pole tide frequency. The Princeton Ocean Model is used to investigate the response of the North Sea to wind forcing. The barotropic numerical ocean model depicts realistic coastlines and bathymetry at 5 ft x 5 ft resolution, with 97 x 73 grid points. The monthly mean wind fields for the 40-year period (1958-1997) from the National Centers for Atmospheric Prediction (NCEP) reanalysis were used to force the model. The winds were converted to stress with a neutral drag coefficient that varied linearly with windspeed (instead of using the NCEP windstress). A 5-day simulation was made for each month until the resulting flow regime came into equilibrium, and model water levels at various station locations were saved for comparison with tidal-gauge observed sea levels from the Permanent Service for Mean Sea Level (PSMSL). The comparison is made for 10 North Sea stations with high quality tide gauge data. We find: (1) good agreement in annual and semi-annual phases and in the trend of amplitude w.r.t. latitude; (2) more importantly for this study, the model-predicted and observed non-seasonal sea level variations show a very significant temporal correlation as well as spectral coherence. However, a large amplitude difference exists between the two sets -- the overall amplitude variability of the observed is generally a factor of 2-3 larger than the model prediction (this same phenomenon has been reported in ocean circulation studies, although the cause is not yet clear.) Our results indicate that the wind forcing is the main cause of the observed large pole tide in the North Sea.

OConnor, W.; Chao, B. F.; Zheng, D. W.; Au, Z. Y.

1998-01-01

235

Tacoma Power Weatherization  

E-print Network

Tacoma Power Weatherization Specifications August 2009 KnowYourPower.com | #12;TACOMA POWER WEATHERIZATION SPECIFICATIONS 2009 edition Page 2 #12;TACOMA POWER WEATHERIZATION SPECIFICATIONS 2009 edition

236

Weather Cycles  

NSDL National Science Digital Library

We are professionals in the teaching profession. We designed this project for children ranging from 4th grade to 6th grade. This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. YOU WILL NEED: Paper with copied questions, Overhead projector and Students broken up into groups of 3. Form groups of three. Have each group explore the following simulation: Weather Maker Simulator Have students use the simulation to answer the following questions on paper. They should be discussing the questions in their groups. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What ...

Mitchell, Mrs.

2010-09-23

237

Weather control  

SciTech Connect

Weather modification, the intentional altering of atmospheric conditions to suit the purposes of humankind, has five basic forms: (1) fog dissipation; (2) rain and snow enhancement; (3) hail suppression; (4) lightning suppression; and (5) the abatement of severe storms such as hurricanes and tornadoes. The dissipation of fog and the seeding of clouds with dry ice or silver iodide to produce rain are the most successful weather modification techniques. Both are used extensively and with varying degrees of success in the United States and around the world. Cloud seeding, though, is not effective in easing the harshness of a drought, such as the one that hit the Southwest, Midwest and Great Plains this summer.

Leepson, M.

1980-09-05

238

Weather Watchers  

NSDL National Science Digital Library

Students are introduced to some essential meteorology concepts so they more fully understand the impact of meteorological activity on air pollution control and prevention. First, they develop an understanding of the magnitude and importance of air pressure. Next, they build a simple aneroid barometer to understand how air pressure information is related to weather prediction. Then, students explore the concept of relative humidity and its connection to weather prediction. Finally, students learn about air convection currents and temperature inversions. In an associated literacy activity, students learn how scientific terms are formed using Latin and Greek roots, prefixes and suffixes, and are introduced to the role played by metaphor in language development. Note: Some of these activities can be conducted simultaneously with the air quality activity (What Color Is Your Air Today?) of Air Pollution unit, Lesson 1.

Integrated Teaching And Learning Program

239

National Weather Service  

MedlinePLUS

HOME FORECAST Local Graphical Aviation Marine Rivers and Lakes Hurricanes Severe Weather Fire Weather Sun/Moon Long Range Forecasts Climate Prediction PAST WEATHER Past Weather Heating/Cooling Days Monthly ...

240

Development of Operational Wave-Tide-Storm surges Coupling Prediction System  

NASA Astrophysics Data System (ADS)

The Korean Peninsula is surrounded by the Yellow Sea, East China Sea, and East Sea. This complex oceanographic system includes large tides in the Yellow Sea and seasonally varying monsoon and typhoon events. For Korea's coastal regions, floods caused by wave and storm surges are among the most serious threats. To predict more accurate wave and storm surges, the development of coupling wave-tide-storm surges prediction system is essential. For the time being, wave and storm surges predictions are still made separately in KMA (Korea Meteorological Administration) and most operational institute. However, many researchers have emphasized the effects of tides and storm surges on wind waves and recommended further investigations into the effects of wave-tide-storm surges interactions and coupling module. In Korea, especially, tidal height and current give a great effect on the wave prediction in the Yellow sea where is very high tide and related research is not enough. At present, KMA has operated the wave (RWAM : Regional Wave Model) and storm surges/tide prediction system (STORM : Storm Surges/Tide Operational Model) for ocean forecasting. The RWAM is WAVEWATCH III which is a third generation wave model developed by Tolman (1989). The STORM is based on POM (Princeton Ocean Model, Blumberg and Mellor, 1987). The RWAM and STORM cover the northwestern Pacific Ocean from 115°E to 150°E and from 20°N to 52°N. The horizontal grid intervals are 1/12° in both latitudinal and longitudinal directions. These two operational models are coupled to simulate wave heights for typhoon case. The sea level and current simulated by storm surge model are used for the input of wave model with 3 hour interval. The coupling simulation between wave and storm surge model carried out for Typhoon Nabi (0514), Shanshan(0613) and Nari (0711) which were effected on Korea directly. We simulated significant wave height simulated by wave model and coupling model and compared difference between uncoupling and coupling cases for each typhoon. When the typhoon Nabi hit at southern coast of Kyushu, predicted significant wave height reached over 10 m. The difference of significant wave height between wave and wave-tide-storm surges model represents large variation at the southwestern coast of Korea with about 0.5 m. Other typhoon cases also show similar results with typhoon Nabi case. For typhoon Shanshan case the difference of significant wave height reached up to 0.3 m. When the typhoon Nari was affected in the southern coast of Korea, predicted significant wave height was about 5m. The typhoon Nari case also shows the difference of significant wave height similar with other typhoon cases. Using the observation from ocean buoy operated by KMA, we compared wave information simulated by wave and wave-storm surges coupling model. The significant wave height simulated by wave-tide-storm surges model shows the tidal modulation features in the western and southern coast of Korea. And the difference of significant wave height between two models reached up to 0.5 m. The coupling effect also can be identified in the wave direction, wave period and wave length. In addition, wave spectrum is also changeable due to coupling effect of wave-tide-storm surges model. The development, testing and application of a coupling module in which wave-tide-storm surges are incorporated within the frame of KMA Ocean prediction system, has been considered as a step forward in respect of ocean forecasting. In addition, advanced wave prediction model will be applicable to the effect of ocean in the weather forecasting system. The main purpose of this study is to show how the coupling module developed and to report on a series of experiments dealing with the sensitivities and real case prediction of coupling wave-tide-storm surges prediction system.

You, S. H.; Park, S. W.; Kim, J. S.; Kim, K. L.

2009-04-01

241

Modelling alongshore flow in a semi-enclosed lagoon strongly forced by tides and waves  

NASA Astrophysics Data System (ADS)

Alongshore flows strongly driven by tides and waves is studied in the context of a one-dimensional numerical model. Observations from field surveys performed in a semi-enclosed lagoon (1.7 km×0.2 km) outside Xai-Xai, Mozambique, are used to validate the model results. The model is able to capture most of the observed temporal variability of the current, but sea surface height tends to be overestimated at high tide, especially during high wave events. Inside the lagoon we observed a mainly uni-directional alongshore current, with speeds up to 1 ms-1. The current varies primarily with the tide, being close to zero near low tide, generally increasing during flood and decreasing during ebb. The observations revealed a local minimum in the alongshore flow at high tide, which the model was successful in reproducing. Residence times in the lagoon were calculated to be less than one hour with wave forcing dominating the flushing. At this beach a high number of drowning casualties have occurred, but no connection was found between them and strong current events in a simulation covering the period 2011-2012.

Taskjelle, Torbjørn; Barthel, Knut; Christensen, Kai H.; Furaca, Noca; Gammelsrød, Tor; Hoguane, António M.; Nharreluga, Bilardo

2014-08-01

242

Weather Forecasting for Weather Derivatives  

Microsoft Academic Search

Abstract: We take a nonstructural time-series approach to modeling and forecasting daily average temperature in ten U.S. cities, and we inquire systematically as to whether it may prove useful from the vantage point of participants in the weather derivatives market. The answer is, perhaps surprisingly, yes. Time series modeling reveals both strong conditional mean dynamics,and conditional variance dynamics in daily

Sean D. Campbell; Francis X. Diebold

2005-01-01

243

Non-stationary internal tides observed with satellite altimetry  

NASA Astrophysics Data System (ADS)

Temporal variability of the internal tide is inferred from a 17-year combined record of Topex/Poseidon and Jason satellite altimeters. A global sampling of along-track sea-surface height wavenumber spectra finds that non-stationary variance is generally 25% or less of the average variance at wavenumbers characteristic of mode-1 tidal internal waves. With some exceptions the non-stationary variance does not exceed 0.25 cm2. The mode-2 signal, where detectable, contains a larger fraction of non-stationary variance, typically 50% or more. Temporal subsetting of the data reveals interannual variability barely significant compared with tidal estimation error from 3-year records. Comparison of summer vs. winter conditions shows only one region of noteworthy seasonal changes, the northern South China Sea. Implications for the anticipated SWOT altimeter mission are briefly discussed.

Ray, R. D.; Zaron, E. D.

2011-09-01

244

Non-Stationary Internal Tides Observed with Satellite Altimetry  

NASA Technical Reports Server (NTRS)

Temporal variability of the internal tide is inferred from a 17-year combined record of Topex/Poseidon and Jason satellite altimeters. A global sampling of along-track sea-surface height wavenumber spectra finds that non-stationary variance is generally 25% or less of the average variance at wavenumbers characteristic of mode-l tidal internal waves. With some exceptions the non-stationary variance does not exceed 0.25 sq cm. The mode-2 signal, where detectable, contains a larger fraction of non-stationary variance, typically 50% or more. Temporal subsetting of the data reveals interannual variability barely significant compared with tidal estimation error from 3-year records. Comparison of summer vs. winter conditions shows only one region of noteworthy seasonal changes, the northern South China Sea. Implications for the anticipated SWOT altimeter mission are briefly discussed.

Ray, Richard D.; Zaron, E. D.

2011-01-01

245

FINITE ELEMENT MODEL FOR TIDES AND CURRENTS WITH FIELD APPLICATIONS.  

USGS Publications Warehouse

A finite element model, based upon the shallow water equations, is used to calculate tidal amplitudes and currents for two field-scale test problems. Because tides are characterized by line spectra, the governing equations are subjected to harmonic decomposition. Thus the solution variables are the real and imaginary parts of the amplitude of sea level and velocity rather than a time series of these variables. The time series is recovered through synthesis. This scheme, coupled with a modified form of the governing equations, leads to high computational efficiency and freedom from excessive numerical noise. Two test-cases are presented. The first is a solution for eleven tidal constituents in the English Channel and southern North Sea, and three constituents are discussed. The second is an analysis of the frequency response and tidal harmonics for south San Francisco Bay.

Walters, Roy A.

1988-01-01

246

Mountain Weather  

NSDL National Science Digital Library

Mountains can be awe-inspiring both for the vistas they provide and for the weather events and long-term climate systems they support. This interactive feature illustrates how a moisture-laden air mass interacts with a mountain slope to produce characteristic patterns of precipitation over the mountain and surrounding areas. Viewers can see how clouds and precipitation form as the air mass ascends the windward side of the peak, and observe the rain shadow created on the leeward side by the descending, warmed, and moisture-depleted air. A background essay and list of discussion questions supplement the interactive feature.

247

The front on the Northern Flank of Georges Bank in spring: 1. Tidal and subtidal variability  

E-print Network

by a mode 1 internal wave at the M2 frequency, with cross-bank velocities comparable to the barotropic tide and shipboard acoustic Doppler current profiler surveys revealed the variability of the intense internal tide on the northern edge of Georges Bank. The nature of the internal tide was modulated by episodic surface intrusions

Kurapov, Alexander

248

Role of tides in Arctic ocean\\/ice climate  

Microsoft Academic Search

A three-dimensional coupled ocean\\/ice model, intended for long-term Arctic climate studies, is extended to include tidal effects. From saved output of an Arctic tides model, we introduce parameterizations for (1) enhanced ocean mixing associated with tides and (2) the role of tides fracturing and mobilizing sea ice. Results show tides enhancing loss of heat from Atlantic waters. The impact of

Greg Holloway; Andrey Proshutinsky

2007-01-01

249

Lunar semidiurnal tide at Adelaide and Wuhan at 80 to 100 km height  

Microsoft Academic Search

Lunar tides in the atmosphere have been an interesting subject despite of their small amplitude because not only the tide-generating source is well known but also lunar tides are present in the atmosphere. Although having a much smaller amplitude than solar tides, lunar tides are also present in the atmosphere. Lunar tides are attractive for theoretical and observational studies because

X. J. Niu; J. G. Xiong; W. X. Wan; B. Q. Ning; L. B. Liu; R. A. Vincent

2004-01-01

250

Solid Earth and ocean tides estimated from satellite orbit analyses  

Microsoft Academic Search

The earth's tidal deformations cause perturbations in the motions of close earth satellites, observations of which give estimates of the Love number k2 and phase lag ?. The contribution of the ocean tides has generally been considered unimportant, but this is not so. These ocean tides cause the same spectrum of orbital perturbations as the solid tide, and a complete

Kurt Lambeck; Anny Cazenave; Georges Balmino

1974-01-01

251

Downstream Amazon river dynamics under oceanic tide influence  

Microsoft Academic Search

Effect of oceanic tide over downstream Amazon river dynamics has been monitored between 1999 and 2001. River topography and bathymetry has been determined, tide induced water levels fluctuations have been monitored at eleven gauging stations along a 1100 km long fluvial reach, water discharges fluctuations along a tide cycle have been measured at 9 sections during low, medium and high

P. Kosuth; A. Larque; M. Soussa da Silva; N. Filizola

2003-01-01

252

Automatic Red Tide Detection using MODIS Satellite Images  

Microsoft Academic Search

Red tides pose a significant economic and environmental threat in the Gulf of Mexico. Detecting red tide is important for understanding this phenomenon. In this thesis, machine learning approaches based on Random Forests, Support Vector Machines and K-Nearest Neighbors have been evaluated for red tide detection from MODIS satellite images. Detection results using machine learning algorithms were compared to ship

Wijian Cheng

2009-01-01

253

FULLY COMPRESSIVE TIDES IN GALAXY MERGERS  

SciTech Connect

The disruptive effect of galactic tides is a textbook example of gravitational dynamics. However, depending on the shape of the potential, tides can also become fully compressive. When that is the case, they might trigger or strengthen the formation of galactic substructures (star clusters and tidal dwarf galaxies), instead of destroying them. We perform N-body simulations of interacting galaxies to quantify this effect. We demonstrate that tidal compression occurs repeatedly during a galaxy merger, independently of the specific choice of parameterization. With a model tailored to the Antennae galaxies, we show that the distribution of compressive tides matches the locations and timescales of observed substructures. After extending our study to a broad range of parameters, we conclude that neither the importance of the compressive tides (approx15% of the stellar mass) nor their duration (approx10{sup 7} yr) is strongly affected by changes in the progenitors' configurations and orbits. Moreover, we show that individual clumps of matter can enter compressive regions several times in the course of a simulation. We speculate that this may spawn multiple star formation episodes in some star clusters, through, e.g., enhanced gas retention.

Renaud, F.; Boily, C. M. [Observatoire Astronomique and CNRS UMR 7550, Universite de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg (France); Naab, T. [University Observatory, Scheinerstr. 1, D-81679 Munich (Germany); Theis, Ch., E-mail: renaud@astro.u-strasbg.f [Institut fuer Astronomie der Univ. Wien, Tuerkenschanzstr. 17, A-1180 Vienna (Austria)

2009-11-20

254

Earth tides and ocean tidal loading  

Microsoft Academic Search

The tidal deformation of the solid earth is superimposed by the loading effect caused by the ocean tides. There are two contributions: the attraction of the moving water masses and the deformation of the crust due to the water load. Thus, the elasticity of the local crust-mantle structure controls the response. The distribution of the continents and the topography of

Gerhard Jentzsch

1997-01-01

255

Semidiurnal solar tides in the mountain atmosphere  

SciTech Connect

Harmonic analysis of Doppler radar wind profiler data west of the Rocky Mountains has identified a coherent semidiurnal wind system above the wintertime boundary layer at multiple sites in the region. The unusual characteristics of this mountain wind system (its semidiurnal frequency, amplitude, phase, and direction of rotation) suggest that is is a semidiurnal solar tide. Such tides have not been previously documented in the mountain atmosphere or in the troposphere generally but, because semidiurnal signatures are well known in surface barometric traces, and large amplitude semidiurnal tides are known in the upper atmosphere, they are not unexpected. Our future research on this semidiurnal cordilleran wind system will focus on obtaining sufficient data to resolve further the vertical structure, seasonal variation, and spatial variations of the wind system. Of particular interest is the role of the Rocky Mountains and other cordilleras in modifying the global tides. It remains to be seen whether semidiurnal cordilleran circulations will be of sufficient magnitude to be observed across major arcuate-shaped east-west-oriented mountain massifs such as the Alps. There, wind systems may develop in response to pressure gradients (Frei and Davies, 1993) that form across the Alps due to differences in the amplitudes and phases of semidiurnal and diurnal pressure oscillations on the north and south sides of the mountain barrier.

Whiteman, C.D.; Bian, X.

1994-09-01

256

Antarctic tides from GRACE satellite accelerations  

NASA Astrophysics Data System (ADS)

Models are routinely used to remove the effects of global ocean tides from GRACE data during processing to reduce temporal aliasing into monthly GRACE solutions. These models have typically been derived using data from satellite altimeter missions such as TOPEX/Poseidon. Therefore the polar components of tide models aren't well constrained by altimetry data, potentially resulting in errors that are likely to alias into monthly GRACE gravity fields at all latitudes. Nine years of GRACE inter-satellite accelerations are inverted to solve for corrections to the amplitude and phase of major solar and lunar ocean tides at latitudes south of 50°S using a mascon approach. The tide model originally applied to the data was GOT4.7, truncated to maximum degree and order 90. Uncertainty estimates are derived from tidal solutions on land, and by subtracting two independent solutions that each use 4.5 years of data. Features in the M2, K1, S2, and O1 solutions that rise above the noise floor likely represent errors in the GOT4.7 model. This ill-posed problem requires regularization; Tikhonov damping and truncated SVD are compared. The regularization strength is optimized by calculating residuals for accelerations withheld from the inversion at different regularization strengths. This regularization limits the inversion's resolution, which is characterized at different latitudes.

Killett, B.; Desai, S. D.; Yuan, D.; Watkins, M. M.; Wiese, D. N.; Zlotnicki, V.

2012-12-01

257

Harmful Algal Blooms: Brown Tide Blooms  

NSDL National Science Digital Library

This University of Maryland SeaGrant web page discusses brown tide blooms, particularly those caused by Aureococcus anophagefferens and Aureoumbra lagunesis in Rhode Island and Texas, respectively. The page explores the economic and ecological effects in both regions and highlights various theories regarding their formation and recurrence.

Kane, Andrew; Jacobs, Dan; The Aquatic Pathobiology Center, University of Maryland; SeaGrant

258

Characterizing internal tides near the Luzon Strait  

NASA Astrophysics Data System (ADS)

In the Luzon Strait, which lies between the Philippines and Taiwan and connects the western Pacific Ocean and the South China Sea, ridges extending along the ocean bottom generate large internal tides—waves with a tidal frequency within the ocean, not on its surface—that propagate into the South China Sea and the Pacific Ocean.

Balcerak, Ernie

2013-09-01

259

Arctic Ocean tides from GRACE satellite accelerations  

NASA Astrophysics Data System (ADS)

Models are routinely used to remove the effects of global ocean tides from GRACE data during processing to reduce temporal aliasing into monthly GRACE solutions. These models have typically been derived using data from satellite altimeters such as TOPEX/Poseidon. Therefore the Arctic ocean components of tide models are not constrained by altimetry data, potentially resulting in errors that are likely to alias into monthly GRACE gravity fields at all latitudes. Seven years of GRACE inter-satellite accelerations are inverted to solve for corrections to the amplitude and phase of major solar and lunar ocean tides at latitudes north of 50°N using a mascon approach. The tide model originally applied to our data was FES2004, truncated to maximum degree lmax = 90. Simulations are performed to verify that our inversion algorithm works as designed. Uncertainty estimates are derived from tidal solutions on land, and by subtracting two independent solutions that each use 3.5 years of data. Features above the noise floor in the M2, K1, S2, and O1 solutions likely represent errors in FES2004. Errors due to truncating the spherical harmonic expansion of FES2004 are too small, and errors in the land mask model (needed to transform sea surface heights into mass) only affect coastal areas and do not produce similar relative amplitudes for any examined tides. In the oceans north of 50°N, these residuals tend to reduce the FES2004 amplitudes for M2, K1, S2, and O1. Reductions in the variance of accelerations not used in our inversion suggest that our results can be used to improve GRACE processing.

Killett, B.; Wahr, J.; Desai, S.; Yuan, D.; Watkins, M.

2011-11-01

260

Generation of diurnal K1 internal tide in the Luzon Strait and its influence on surface tide in the South China Sea  

Microsoft Academic Search

The predominance of diurnal surface tides over semidiurnal surface tides in the South China Sea (SCS) has been attributed to the near-resonance response of the former in the SCS. Recent observations further revealed vigorous internal tides in the northern SCS. Conceivably, internal tides generated in the Luzon Strait could modify the surface tide in the SCS. We use a three-dimensional

Sen Jan; Ching-Sheng Chern; Joe Wang; Shenn-Yu Chao

2007-01-01

261

Satellite-based red tide monitoring in the Korean coastal waters  

NASA Astrophysics Data System (ADS)

Occurrence and spread of red tide known to develop in the environment of eutrophic coastal region, cause living sea creatures great damages such as fishkills, shellfish poisoning, mortality in benthic habitats. In the Korean coastal waters, harmful Cochlodinium polykrikoides blooms frequently appeared mainly in the environment of semi-enclosed bay, and it has also occurred and distributed to the East Sea of the Korean Peninsula since 1995. Ocean color observation satellite images, have successfully distinguished HABs in the coastal region. Geostationary ocean color imager (GOCI), a new ocean color satellite imager placed in a geostationary orbit, has advantage over other ocean color sensors in that it collects images every hour during daytime enabling monitoring of temporal variability in ocean environment. GOCI has successfully identified the short-term variations in coastal water turbidity, investigated ocean surface current and detected eddies in the Korea coasts and East China Sea with a spatial resolution of 500 m. Thus, GOCI can be effectively applied to the monitoring of the dynamic movement and spread of the red tide. In this study, distribution and spread range of red tide, which had been found in the east coast of Korean peninsula in August 2013, was monitored using GOCI. The red tide had originally been occurred in the Southeatern coastal area of Korean peninsula in the middle of July 2013 and spread to the east coast of the peninsula. Several days of cruise was carried out for the identification of the red tide species and their optical characteristics. GOCI was employed to detect the patches of the red tide and its movement for about a month based upon the results of the field works.

Choi, Jong-Kuk; Park, Young Je; Noh, Jae Hoon; Min, Jee-Eun

2014-05-01

262

The Weather Dude  

NSDL National Science Digital Library

The Weather Dude is a weather education Web site offered by meteorologist Nick Walker of The Weather Channel. For kids, the site offers a great online textbook entitled Weather Basics, which explains everything from precipitation to the seasons, using simple text and fun graphics. Other fun things for kids include weather songs, questions and quizzes, weather proverbs, and more. Teachers are also provided with helpful resources such as weather activity sheets and printable blank maps, as well as many other links to weather forecasts and information that will help make teaching about weather fun.

Walker, Nick.

2002-01-01

263

Diurnal and spatial variabilities of monsoonal CG lightning and precipitation and their association with the synoptic weather conditions over South Korea  

NASA Astrophysics Data System (ADS)

The spatial and temporal variations in cloud-to-ground (CG) lightning and precipitation during the summer monsoon months in Korea have been analyzed in relation to the regional synoptic weather conditions. The lightning data used in this study were collected from a lightning detection network installed by the Korean Meteorological Administration, while the precipitation data were collected from 386 Automatic Weather Stations spread over the entire Korean Peninsula during 2000 to 2001. A distinctive morning peak of precipitation is observed over the midwest region of Korea. Along the east coast, little precipitation and CG flash counts are found. Despite the strong afternoon peaks of convective rainfall due to the high elevation over the southern inland region, the south coast shows nocturnal or early morning peaks, which represents a common oceanic pattern of flash counts. In 2000, the nighttime peak for lightning counts dominates over the southern area, while the afternoon peak was strong in the midland during the summer, mainly due to the northward transportation of moisture to the Korean Peninsula. Conversely, the strong afternoon peak for the southern region was confronted with early morning peaks in the midwestern region during 2001. The eastward transport of moisture has been analyzed and was considered to be dominant in 2001. The study of several warm and cold type fronts in 2000 and 2001 indicate that the warm type fronts in 2000 were associated with very little lightning, while the cold type fronts appeared to be responsible for the occurrence of abundant lightning in 2001, thereby, indicating that the warm and cold type fronts were representative of the local lightning distribution in the respective years.

Hyun, Yu-Kyung; Kar, S. K.; Ha, Kyung-Ja; Lee, J. H.

2010-10-01

264

Effects in the Middle and Upper Atmosphere due to Meteorological and Geospace Variability During 2006  

NASA Astrophysics Data System (ADS)

In the recent geomagnetic quiescent years observations showed that the ionosphere and thermosphere is influenced not only from geospace but also from below by tropospheric weather. This is especially apparent in the observed longitudinal variation of quantities like ion drift, neutral winds, composition, ionospheric current and electron density. The National Center for Atmospheric Research (NCAR) thermosphere-ionosphere-mesosphere-electrodynamics general circulation model (TIME-GCM) can model many of the observed tidal features. In this study we will focus on the migrating and nonmigrating tidal variability due to the effects of meterological variability under realistic geospace conditions for 2006. We quantify the effect on the tides due to the planetary wave activity at the lower boundary by using control simulations. We examine the change in the tidal propagation due to changes in the background atmosphere. We highlight the introduced temporal variability of major tidal components and their effect on the electrodynamics, the ionosphere and upper thermosphere.

Maute, A. I.; Hagan, M. E.; Roble, R. G.; Richmond, A. D.

2011-12-01

265

External Resource: Mechanical Weathering  

NSDL National Science Digital Library

A student activity with teacher's sheet, to give the students an opportunity to realize that all rocks weather mechanically and each specific rock type has its own particular rate of weathering. Mechanical weathering is the process of breaking down bedroc

1900-01-01

266

Baroclinic tides in the Southern Indian Ocean from altimetry Claire Maraldi1, ?, *, F. Lyard1, L. Testut1, R. Coleman2, 3, 4 * claire.maraldi@legos.obs-mip.fr  

E-print Network

-track filter (cutoff 400 km and less) Amplitude of the M2 barotropic and baroclinic signal before and after low-90 days Aliased period of M2 : 62.1 days some of the ACC variability is analyzed as being M2 tide RMS barotropic tide have been reviewed to better understand the M2 baroclinic generation in the southern Indian

267

Apparent Relations Between Solar Activity and Solar Tides Caused by the Planets  

NASA Technical Reports Server (NTRS)

A solar storm is a storm of ions and electrons from the Sun. Large solar storms are usually preceded by solar flares, phenomena that can be characterized quantitatively from Earth. Twenty-five of the thirty-eight largest known solar flares were observed to start when one or more tide-producing planets (Mercury, Venus, Earth, and Jupiter) were either nearly above the event positions (less than 10 deg. longitude) or at the opposing side of the Sun. The probability for this to happen at random is 0.039 percent. This supports the hypothesis that the force or momentum balance (between the solar atmospheric pressure, the gravity field, and magnetic field) on plasma in the looping magnetic field lines in solar corona could be disturbed by tides, resulting in magnetic field reconnection, solar flares, and solar storms. Separately, from the daily position data of Venus, Earth, and Jupiter, an 11-year planet alignment cycle is observed to approximately match the sunspot cycle. This observation supports the hypothesis that the resonance and beat between the solar tide cycle and nontidal solar activity cycle influences the sunspot cycle and its varying magnitudes. The above relations between the unpredictable solar flares and the predictable solar tidal effects could be used and further developed to forecast the dangerous space weather and therefore reduce its destructive power against the humans in space and satellites controlling mobile phones and global positioning satellite (GPS) systems.

Hung, Ching-Cheh

2007-01-01

268

Modelling tides and surface drift in the Arabian Gulf—application to the Gulf oil spill  

NASA Astrophysics Data System (ADS)

A tide and surge forecasting model capable of predicting conditions for up to 5 days ahead has been developed to provide environmental data on tides, currents and particle trajectories in the Arabian Gulf. A two-dimensional depth-integrated model on a 5' × 5' grid of the entire Gulf, driven by a 10 constituent tidal forcing at the mouth near the Strait of Hormuz and by meteorological forecasts from the United Kingdom Meteorological Office global numerical weather prediction model was used to provide hourly distributions of the depth-averaged tidal and wind-driven currents. Following the discharge of oil from Mina Al Ahmadi into the Gulf in January 1991 an oil spill model was interfaced to the tide and surge model, providing forecasts of the movement and spread of the oil slick. The oil spill model used a three-dimensional particle tracking algorithm to model the dispersion of the oil so that surface and sub-surface concentrations could be determined. The effects of surface evaporation and decay of the oil were included in the model.

Proctor, Roger; Flather, Roger A.; Elliott, Alan J.

1994-04-01

269

Deriving long-term sea level variations at tide gauge stations in Atlantic North America  

NASA Astrophysics Data System (ADS)

Tide gauge recording is an indispensable geodetic tool to study local sea level variations in coastal areas and mean sea level trends on a global scale. Combined with satellite altimetry sea surface heights or GNSS- derived ellipsoidal heights, tide gauge records have been used for deriving estimates of vertical crustal motion elsewhere. The objective of our paper is to study the capabilities of the method of singular spectrum analysis, which is generically related to empirical orthogonal functions/principal component analysis technique, to derive local long-term and secular sea level trends. This method allows one to extract any anomalous sea level signals, which is difficult to achieve by the conventional harmonic analysis. We use a set of tide gauge stations in Atlantic Canada and the USA extracted from the monthly PSMSL data base. To create continuous time series, we fill all time gaps by interpolating the main periodic and trend components of the sea level signal using the least squares harmonic analysis. We analyze all tide gauge time series simultaneously through singular value decomposition of the time-lagged series combined in a data trajectory matrix. This enables us to extract and separate the main modes of variability of the local sea level and to study only the long-term spatio-temporal patterns in the sea level variations. Our preliminary results show that the length of the tide gauge time series and the relative contribution of the signals to the total sea level variance are the two crucial factors that may preclude the separation of the local secular sea level fall or rise from any decadal sea level variability. The outcome of our study will be useful for combined satellite altimetry/TG/GRACE studies of sea level changes in the coastal areas, studies of vertical crustal motion due to postglacial rebound in the region, as well as the definition and realization of a dynamic reference surface for orthometric heights in North America.

Ince, E. S.; Sideris, M. G.; Rangelova, E.

2009-05-01

270

Tide-influenced sedimentary environments and facies  

SciTech Connect

This volume contains examples of recent as well as fossil tide-influenced sedimentary facies. Studies of recent tidal processes and sediments provide an insight into the way in which tidal facies and sequences develop, and into the processes which are active. The studies performed on fossil rocks give information on one-to-one scale model experiments that have been executed by nature both relatively recently and in the distant past. In this work, the parallel presentation of papers on recent and fossil examples of tide-influenced sedimentary facies and environments follows the philosophy of comparative sedimentology, aiming at an understanding of both the past and the present, with the aim also, of forecasting future developments.

De Boer, P.L.; Van Gelder, A.; Nio, S.D.

1988-01-01

271

Prospects for Improved Forecasts of Weather and Short-Term Climate Variability on Subseasonal (2-Week to 2-Month) Times Scales  

NASA Technical Reports Server (NTRS)

This workshop, held in April 2002, brought together various Earth Sciences experts to focus on the subseasonal prediction problem. While substantial advances have occurred over the last few decades in both weather and seasonal prediction, progress in improving predictions on these intermediate time scales (time scales ranging from about two weeks to two months) has been slow. The goals of the workshop were to get an assessment of the "state of the art" in predictive skill on these time scales, to determine the potential sources of "untapped" predictive skill, and to make recommendations for a course of action that will accelerate progress in this area. One of the key conclusions of the workshop was that there is compelling evidence for predictability at forecast lead times substantially longer than two weeks. Tropical diabatic heating and soil wetness were singled out as particularly important processes affecting predictability on these time scales. Predictability was also linked to various low-frequency atmospheric "phenomena" such as the annular modes in high latitudes (including their connections to the stratosphere), the Pacific/North American (PNA) pattern, and the Madden Julian Oscillation (MJO). The latter, in particular, was highlighted as a key source of untapped predictability in the tropics and subtropics, including the Asian and Australian monsoon regions.

Schubert, Siegfried; Dole, Randall; vandenDool, Huug; Suarez, Max; Waliser, Duane

2002-01-01

272

ERRATUM: Resonant Tides in Close Orbiting Planets  

Microsoft Academic Search

In the paper ``Resonant Tides in Close Orbiting Planets'' by S. H. Lubow, C. A. Tout, and M. Livio (ApJ, 484, 866 [1997]), there is a misprint in the abstract. The abstract states that ``the torque is exerted in a region where H\\/rp>>1....'' Instead, it should state that ``the torque is exerted in a region where H\\/rp<<1....''

S. H. Lubow; C. A. Tout; M. Livio

1999-01-01

273

Semidiurnal Internal Tides in Massachusetts Bay  

Microsoft Academic Search

bility may occur. The total internal wave energy occurring in a bandwidth of 7.32 X 10 - cph, centered on the semidiurnal frequency, is approximately 4.3 X 105 ergs\\/cm% which is about 8.6% of the total energy of the barotropic tide. These results, which were deduced from linear theory, may not be entirely accurate because the asymmetry of the temperature

David Halpern

1971-01-01

274

New England Red Tide Outbreak 2005  

NSDL National Science Digital Library

This Woods Hole Oceanographic Institution website provides general information about the 2005 outbreak of toxic alga Alexandrium fundyense, a type of algae that causes red tide. This bloom outbreak is the worst in New England since 1972 and occurred off of the Gulf of Maine. The site also addresses possible causes for the bloom, why the bloom was so intense and widespread, and its economic cost. The web page features color diagrams of infected sites, pictures, and links to related sites.

2009-07-16

275

Comparison between physical variables acquired by a new multiparametric platform, ELFO, and data calculated by a three-dimensional hydrodynamic model in different weather conditions at Tiber River mouth (Latium coast, Italy)  

NASA Astrophysics Data System (ADS)

The coastal ecosystem is characterized by high variability physical processes, which are strongly influenced by sudden changes in weather conditions. For this reason instruments able to collect data in a short time or mathematical models able to simulate the same phenomena from experimental data are basic. In this study in situ data are compared with data calculated by three-dimensional hydrodynamic model. The multiparametric platform was developed ad hoc by Laboratory of Experimental Oceanology and Marine Ecology (DECOS, Tuscia University) for coastal monitoring by small vessels (ELFO), and integrates temperature, conductivity, dissolved oxygen and suspended solids measures with bio-optical measures like fluorescence, photosynthetic efficiency and PAR. The hydrodynamic model is the three-dimensional coastal hydrodynamic DELFT3D-FLOW simulating processes of temperature and salinity diffusion and the transport of suspended sediment (cohesive and non cohesive) in the water column. This study analyses the area at mouth of Tiber river investigated by two surveys wiht different weather conditions. Data collected during the first survey were used to calibrate the DELFT3D-FLOW model which computational domain extends from the Argentario headland to Capo Anzio. A microscale wind field (resolution of about 7 km), provided by the atmospheric model COSMO-ME (developed by CNMCA of Aeronautica Militare, Italy), was used to reproduce the hydrodynamic field and the distribution of the physical variables of the whole period. In this way the data calculated by the model can be compared with those collected in situ during the second survey. Moreover dynamic phenomena existed between the two monitoring periods can be investigated.

Bonamano, Simone; Piermattei, Viviana; Marcelli, Marco; Peviani, Maximo

2010-05-01

276

Body Tides of a Realistic Earth  

NASA Astrophysics Data System (ADS)

A precise modelling of the Earth tides is necessary to correct the space gravimetry observations, from satellites such as GRACE and GOCE. It is also useful to correct ground measurements, and even more important for superconducting gravimeters, which have a 10 nGal precision. The Earth response (deformation and gravity) to tides or atmospheric load is generally computed assuming radial symmetry in stratified Earth models, at the hydrostatic equilibrium. Our study aims at providing a new Earth tide model, which accounts for the whole complexity of a more realistic Earth. Our model is based on a dynamically consistent equilibrium state which includes lateral variations in density and rheological parameters (shear and bulk moduli), and interface topographies. We use a finite element method and we solve numerically the gravito-elasticity equations. The deviation from the hydrostatic equilibrium has been taken into account as a first order perturbation. The equations are written in the Fourier domain, in order to allow degree one translational and rotational modes of the Earth. We investigate the impact on Earth tidal response of an equilibrium state different from hydrostatic and of the topography of the interfaces, for a simple model of lateral variation: a spherical anomaly in the mantle, which can represent plumes and superplumes. At the M2 frequency (semi-diurnal), we estimate the order of magnitude of the perturbation as a function of the radius and physical parameters of the anomaly.

Metivier, L.; Greff-Lefftz, M.; Diament, M.

2005-12-01

277

Modeling tides around Pine Island, Antarctic  

NASA Astrophysics Data System (ADS)

Tide is one of the least studied factors in ocean-sea ice coupled systems, which poses great challenges in our understanding of such coupled systems and great uncertainty in the hindcast and forecast of climate. In order to study the effects of tides in coupled ocean-sea ice systems, tidal signal is added to a coupled ocean-sea ice model around Pine Island, Antarctic. The oceanic component of the coupled model, which has a horizontal resolution of 1km and 70 levels in the vertical direction, is configured from the Massachusetts Institute of Technology General Circulation Model (MITgcm). The tidal boundary condition is from Circum-Antarctic Tide Simulation (CATS2008a). When sea surface height is solved explicitly, Flather boundary condition proved to be an effective way to add tidal signal in a regional ocean circulation model. Instead of solving sea surface height explicitly, MITgcm separates the pressure field into surface, hydrostatic, and non-hydrostatic parts, and solves the pressure field as a Poisson equation. Our preliminary results indicate that using the Poisson equation method poses unique challenges when applying tidal boundary condition to MITgcm. Suitable numerical schemes will be designed to add tidal signal to MITgcm. Tidal solution from MITgcm will be compared with that from CATS and available observations.

Wang, X.; Schodlok, M.; Menemenlis, D.

2012-12-01

278

Interactions between tides and other frequencies in the Indonesian seas  

NASA Astrophysics Data System (ADS)

Interactions of tidal constituents and the transfer of energy from the tidal frequencies to other frequencies are investigated using 3-D tidal simulations for the Indonesian seas, focusing on an area of active internal tides. Semidiurnal tides strongly affect diurnal tides; however, semidiurnal tides are essentially unaffected by diurnal tides. The semidiurnal and diurnal constituents interact with each other through non-linear interference, both destructive and constructive. Semidiurnal tides generate harmonics at nearly the diurnal frequency and higher vertical wavenumbers. In Ombai Strait, these harmonics are out of phase with the diurnal tides and interact destructively with the diurnal tides, effectively negating the diurnal response in some locations. However, this is not a general response, and interactions differ between locations. Energy is also transferred from both semidiurnal and diurnal tides to other frequencies across the spectrum, with more energy originating from semidiurnal tides. These energy transfers are not homogeneous, and the spectral responses differ between the Makassar and Ombai Straits, with the region east of Ombai showing a more active surface response compared to a more intense benthic response in Makassar. In deep water away from topography, velocity spectra generally follow the Garrett-Munk (GM) relation. However, in areas of internal tide generation, spectral density levels exceed GM levels, particularly between 4 and 8 cycles per day (cpd), indicating increased non-linear interactions and energy transfer through resonant interactions. The model indicates strong surface trapping of internal tides, with surface velocity spectra having significantly higher energy between 4 and 8 cpd even 100 km away from the prominent sill generating the internal tides.

Robertson, Robin

2011-01-01

279

LETTER doi:10.1038/nature12400 A rigid and weathered ice shell on Titan  

E-print Network

LETTER doi:10.1038/nature12400 A rigid and weathered ice shell on Titan D. Hemingway1 , F. Nimmo1 , H. Zebker2 & L. Iess3 Several lines of evidence suggest that Saturn's largest moon, Titan, has to wavelengths that are controlled by tides and rotation, we suggest that Titan's moment of inertia may be even

Nimmo, Francis

280

A Climatology of Fair-Weather Cloud Statistics at the Atmospheric Radiation Measurement Program Southern Great Plains Site: Temporal and Spatial Variability  

SciTech Connect

In previous work, Berg and Stull (2005) developed a new parameterization for Fair-Weather Cumuli (FWC). Preliminary testing of the new scheme used data collected during a field experiment conducted during the summer of 1996. This campaign included a few research flights conducted over three locations within the Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF) Southern Great Plains (SGP) site. A more comprehensive verification of the new scheme requires a detailed climatology of FWC. Several cloud climatologies have been completed for the ACRF SGP, but these efforts have focused on either broad categories of clouds grouped by height and season (e.g., Lazarus et al. 1999) or height and time of day (e.g., Dong et al. 2005). In these two examples, the low clouds were not separated by the type of cloud, either stratiform or cumuliform, nor were the horizontal chord length (the length of the cloud slice that passed directly overhead) or cloud aspect ratio (defined as the ratio of the cloud thickness to the cloud chord length) reported. Lane et al. (2002) presented distributions of cloud chord length, but only for one year. The work presented here addresses these shortcomings by looking explicitly at cases with FWC over five summers. Specifically, we will address the following questions: •Does the cloud fraction (CF), cloud-base height (CBH), and cloud-top height (CTH) of FWC change with the time of day or the year? •What is the distribution of FWC chord lengths? •Is there a relationship between the cloud chord length and the cloud thickness?

Berg, Larry K.; Kassianov, Evgueni I.; Long, Charles N.; Gustafson, William I.

2006-03-30

281

GPS estimates of ocean tide loading in NW-France: Determination of ocean tide loading constituents and comparison with a recent ocean tide model  

E-print Network

1 GPS estimates of ocean tide loading in NW-France: Determination of ocean tide loading Descartes, 67000 Strasbourg, France. Accepted date. Received date; in original form date Short title: GPS scales by the means of spurious signals. GPS measurements, in turn, could provide local improvements

Paris-Sud XI, Université de

282

NONLINEAR TIDES IN CLOSE BINARY SYSTEMS  

SciTech Connect

We study the excitation and damping of tides in close binary systems, accounting for the leading-order nonlinear corrections to linear tidal theory. These nonlinear corrections include two distinct physical effects: three-mode nonlinear interactions, i.e., the redistribution of energy among stellar modes of oscillation, and nonlinear excitation of stellar normal modes by the time-varying gravitational potential of the companion. This paper, the first in a series, presents the formalism for studying nonlinear tides and studies the nonlinear stability of the linear tidal flow. Although the formalism we present is applicable to binaries containing stars, planets, and/or compact objects, we focus on non-rotating solar-type stars with stellar or planetary companions. Our primary results include the following: (1) The linear tidal solution almost universally used in studies of binary evolution is unstable over much of the parameter space in which it is employed. More specifically, resonantly excited internal gravity waves in solar-type stars are nonlinearly unstable to parametric resonance for companion masses M' {approx}> 10-100 M{sub Circled-Plus} at orbital periods P Almost-Equal-To 1-10 days. The nearly static 'equilibrium' tidal distortion is, however, stable to parametric resonance except for solar binaries with P {approx}< 2-5 days. (2) For companion masses larger than a few Jupiter masses, the dynamical tide causes short length scale waves to grow so rapidly that they must be treated as traveling waves, rather than standing waves. (3) We show that the global three-wave treatment of parametric instability typically used in the astrophysics literature does not yield the fastest-growing daughter modes or instability threshold in many cases. We find a form of parametric instability in which a single parent wave excites a very large number of daughter waves (N Almost-Equal-To 10{sup 3}[P/10 days] for a solar-type star) and drives them as a single coherent unit with growth rates that are a factor of Almost-Equal-To N faster than the standard three-wave parametric instability. These are local instabilities viewed through the lens of global analysis; the coherent global growth rate follows local rates in the regions where the shear is strongest. In solar-type stars, the dynamical tide is unstable to this collective version of the parametric instability for even sub-Jupiter companion masses with P {approx}< a month. (4) Independent of the parametric instability, the dynamical and equilibrium tides excite a wide range of stellar p-modes and g-modes by nonlinear inhomogeneous forcing; this coupling appears particularly efficient at draining energy out of the dynamical tide and may be more important than either wave breaking or parametric resonance at determining the nonlinear dissipation of the dynamical tide.

Weinberg, Nevin N. [Department of Physics, and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Arras, Phil [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States); Quataert, Eliot; Burkart, Josh, E-mail: nevin@mit.edu [Astronomy Department and Theoretical Astrophysics Center, 601 Campbell Hall, University of California, Berkeley, CA 94720 (United States)

2012-06-01

283

Future Weather Station  

NSDL National Science Digital Library

In this activity students build dioramas of futuristic weather stations to demonstrate their knowledge of weather forecasting. They will work in groups to research modern forecasting equipment and techniques, and then build a weather station that will do something we cannot do at present (such as stopping tornadoes). They will present their dioramas and then discuss the pros and cons of controlling the weather.

284

Corridor Integrated Weather System  

Microsoft Academic Search

n Flight delays are now a major problem in the U.S. National Airspace System. A significant fraction of these delays are caused by reductions in en route capacity due to severe convective weather. The Corridor Integrated Weather System (CIWS) is a fully automated weather analysis and forecasting system designed to support the development and execution of convective weather impact mitigation

James E. Evans; Elizabeth R. Ducot

2006-01-01

285

Weather in Your Life.  

ERIC Educational Resources Information Center

Facts and activities related to weather and meteorology are presented in this unit. Separate sections cover the following topics: (1) the water cycle; (2) clouds; (3) the Beaufort Scale for rating the speed and force of wind; (4) the barometer; (5) weather prediction; (6) fall weather in Iowa (sleet, frost, and fog); (7) winter weather in Iowa…

Kannegieter, Sandy; Wirkler, Linda

286

Vertical Crustal Movements in Italy from Tide Gauge and Satellite Altimetry data  

NASA Astrophysics Data System (ADS)

Our goal is to determine vertical crustal movement rates from tide gauge and satellite altimetry measurements. Tide gauges measure sea level, but as they are fixed to the coast, they sense both sea surface height variations and vertical crustal movements. Satellite altimetric measurements determine sea surface height variations directly and can be used to separate the crustal signal from the sea surface height variations in tide gauge measurements. We apply the methodology to the Southern Italy, an area of broad scientific interest, due to its high seismic risk and its location as standpoint for a great bridge that should connect Sicily to the Italian mainland, but it can be exported to any parts of the world where tide gauge observations are available. Along the Italian coastline 26 tide gauge stations with 10-years of continuous data are available. We have explored the sea level data statistically, including a study of the space-time variation of rates, of the optimal way of calculating rates and of the correlation-coefficients between stations. The tidal sea level change rates have a relatively large variability, greatly ascribable to the short time interval of analysis (10 years), and are comprised between -5 and +9 mm/yr with an approximate uncertainty of 0.5 mm/yr. The satellite altimetric data pose a challenge to the joint analysis, due to very different time resolution (10 days versus hourly sampling of tide gauges), sparse spatial sampling of the Mediterranean due to track distances, and the difficulty in acquiring altimetric data in the vicinity of the coast. We have analyzed the satellites Topex/Poseidon and Jason1. The study of Envisat data is under way and it could provide more detailed data, since its track distance is sensibly shorter, even if time sampling interval is 35 days. We explore also the satellite altimetric data statistically, investigating the correlation matrices of the data and the time-space variation of the sea surface change rates. We move along the tracks, trying to approach the coast as near as possible. We construct time series with 10 day sampling interval at discrete locations with the criterion of covering the Mediterranean homogeneously. We calculate histograms as we go near the coast and we find that at a distance of about 45 km from the coast the number of points drastically is reduced leading to a time series with many interruptions. We also find that the sea surface change rates derived from the altimeter have an even greater variability compared to the tide gauges for the same years, showing that changes far from the coast are greater than near the coast. We discuss the problem of how to use the altimeter data in those cases in which the tracks are far from the tide gauges, as is the case for the satellite Topex/Poseidon and the tectonically interesting tide gauge stations of Sicily and Calabria. An adequate space-time interpolation of the satellite data produces maps of spatial variations of sea surface change that are used in the study of the differential sea level rates of tide gauges. We show that geologically consistent crustal uplift rates are found for the highly seismic area of eastern Sicily and Calabria.

Braitenberg, Carla; Lavinia, Tunini; Barbara, Grillo; Nagy, Ildiko'

2010-05-01

287

Australian Severe Weather  

NSDL National Science Digital Library

The Australian Severe Weather Web site is maintained by self proclaimed severe weather enthusiasts Michael Bath and Jimmy Deguara. Other weatherphobes will fully appreciate what the authors have assembled. Everything from weather images, storm news, tropical cyclone data, bush fire and wild fire information, weather observation techniques, and even video clips and Web cam links. Although these other items make the site well rounded, the extensive amount of categorized weather pictures (which are quite extraordinary) are reason enough to visit.

288

What's the Weather?  

NSDL National Science Digital Library

In this lesson, students use daily observations, videos, and activities to learn about meteorology and the changing nature of weather. They will also identify weather events that are commonly reported in the news and discuss how weather affects lives. They should understand that weather can change daily and weather patterns change over the seasons, and that it has characteristics that can be measured and predicted. Suggestions for an optional field trip are also provided.

2005-01-01

289

Oceanic tide maps and spherical harmonic coefficients from Geosat altimetry  

NASA Technical Reports Server (NTRS)

Maps and tables for the global ocean tides, 69 degree N to 68 degree S, derived from two years of Geosat altimetry are presented. Global maps of local and Greenwich admittance of the (altimetric) ocean tide, and maps of amplitude and Greenwich phase lag of the ocean tide are shown for M(sub 2), S(sub 2), N(sub 2), O(sub 1), and K(sub 1). Larger scale maps of amplitude and phases are also shown for regional areas of special interest. Spherical harmonic coefficients of the ocean tide through degree and order 8 are tabulated for the six major constituents.

Cartwright, D. E.; Ray, R. D.; Sanchez, B. V.

1991-01-01

290

Hydroxyl radical generation by red tide algae.  

PubMed

The unicellular marine phytoplankton Chattonella marina is known to have toxic effects against various living marine organisms, especially fishes. However, details of the mechanism of the toxicity of this plankton remain obscure. Here we demonstrate the generation of superoxide and hydroxyl radicals from a red tide unicellular organism, C. marina, by using ESR spectroscopy with the spin traps 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) and N-t-butyl-alpha-phenylnitrone (PBN), and by using the luminol-enhanced chemiluminescence response. The spin-trapping assay revealed productions of spin adduct of superoxide anion (O2-) (DMPO-OOH) and that of hydroxyl radical (.OH) (DMPO-OH) in the algal suspension, which was not observed in the ultrasonic-ruptured suspension. The addition of superoxide dismutase (500 U/ml) almost completely inhibited the formation of both DMPO-OOH and DMPO-OH, and carbon-centered radicals were generated with the disappearance of DMPO-OH after addition of 5% dimethyl sulfoxide (Me2SO) and 5% ethanol. Furthermore, the generation of methyl and methoxyl radicals, which are thought to be produced by the reaction of hydroxyl radical and Me2SO under aerobic condition, was identified using spin trapping with a combination of PBN and Me2SO. Luminol-enhanced chemiluminescence assay also supported the above observations. These results clearly indicate that C. marina generates and releases the superoxide radical followed by the production of hydroxyl radical to the surrounding environment. The velocity of superoxide generation by C. marina was about 100 times faster than that by mammalian phagocytes per cell basis. The generation of oxygen radical is suggested to be a pathogenic principle in the toxication of red tide to susceptible aquaculture fishes and may be directly correlated with the coastal pollution by red tide. PMID:1312810

Oda, T; Akaike, T; Sato, K; Ishimatsu, A; Takeshita, S; Muramatsu, T; Maeda, H

1992-04-01

291

Trapped diurnal internal tides, propagating semidiurnal internal tides, and mixing estimates in the California  

E-print Network

(SRCR) in the Southern California Bight (SCB) on line 90. While finding elevated mixing near topography-Sea Res. II January 3, 2014 #12;SCB. Numerous sources of internal tides at the rough topography in the SCB the Southern California Bight (SCB) [Beckenbach and Terrill, 2008;16 Kim et al., 2011; Nam and Send, 2011

Johnston, Shaun

292

Red Tide Strands South African Rock Lobsters  

NASA Technical Reports Server (NTRS)

Although some red tides form a healthy part of phytoplankton production, recurrent harmful or toxic blooms also occur, with results depending upon the type of plankton and on atmospheric and oceanic conditions. At Elands Bay in South Africa's Western Cape province, about 1000 tons of rock lobsters beached themselves during February 2002, when the decay of dense blooms of phytoplankton caused a rapid reduction in the oxygen concentration of nearshore waters. The lobsters (or crayfish, as they are known locally) moved toward the breaking surf in search of oxygen, but were stranded by the retreating tide. The Multi-angle Imaging SpectroRadiometer's nadir camera acquired these red, green, blue composites on February 2 and 18, 2002, during Terra orbits 11315 and 11548. The colors have been accentuated to highlight the bloom, and land and water have been enhanced separately. The two views show the shoreward migration of the algal bloom. Each image represents an area of about 205 kilometers x 330 kilometers. Elands Bay is situated near the mouth of the Doring River, about 75 kilometers northeast of the jutting Cape Columbine. The term 'red tide' is used to refer to a number of different types of phytoplankton blooms of various hues. The wine color of certain parts of this bloom are consistent with the ciliate species Mesodinium rubrum, which has been associated with recurring harmful algal blooms along the Western Cape coast. Under these conditions, the lobsters are not poisoned. During the recent event, government and military staff transported as many of the living lobsters as possible to areas that were less affected by the red tide. At the same time, people came from across South Africa to gather the undersized creatures for food. The effects of the losses on the maritime economy are expected to be felt over the next few years. MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology. Image credit: NASA/GSFC/LaRC/JPL, MISR Team.

2002-01-01

293

Red Tide Strands South African Rock Lobsters  

NASA Technical Reports Server (NTRS)

Although some red tides form a healthy part of phytoplankton production, recurrent harmful or toxic blooms also occur, with results depending upon the type of plankton and on atmospheric and oceanic conditions. At Elands Bay in South Africa's Western Cape province, about 1000 tons of rock lobsters beached themselves during February 2002, when the decay of dense blooms of phytoplankton caused a rapid reduction in the oxygen concentration of nearshore waters. The lobsters (or crayfish, as they are known locally) moved toward the breaking surf in search of oxygen, but were stranded by the retreating tide.

The Multi-angle Imaging SpectroRadiometer's nadir camera acquired these red, green, blue composites on February 2 and 18, 2002, during Terra orbits 11315 and 11548. The colors have been accentuated to highlight the bloom, and land and water have been enhanced separately. The two views show the shoreward migration of the algal bloom. Each image represents an area of about 205 kilometers x 330 kilometers. Elands Bay is situated near the mouth of the Doring River, about 75 kilometers northeast of the jutting Cape Columbine.

The term 'red tide' is used to refer to a number of different types of phytoplankton blooms of various hues. The wine color of certain parts of this bloom are consistent with the ciliate species Mesodinium rubrum, which has been associated with recurring harmful algal blooms along the Western Cape coast. Under these conditions, the lobsters are not poisoned. During the recent event, government and military staff transported as many of the living lobsters as possible to areas that were less affected by the red tide. At the same time, people came from across South Africa to gather the undersized creatures for food. The effects of the losses on the maritime economy are expected to be felt over the next few years.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

2002-01-01

294

The internal tide off Panama City, Florida  

E-print Network

June 1963 Ma)or Sub)ect: Physical Oceanography THE INTERNAL TIDE OFF PANAMA CITY, FLORIDA A Thesis By Noel E. J. Boston Approved as to style and content by: a an o t e omm ttee a o t e epartm June 1963 856088 ACKNOWLEDGMENTS The work... 3. Kelvin Wave Model. V. CONCLUSIONS. BI BL IOGRAP HY Page 62 62 63 67 72 74 LIST OF TABLES TABLE I. Distribution of survey responsibilities. . Page 13 II Station time table for the R/V SEICHE and the R/V ANTILLA 1200 June 19 to 1200...

Boston, Noel Edward James

2012-06-07

295

What's SO COOL about Red Tide?  

NSDL National Science Digital Library

This Mote Marine Laboratory magazine article details a new study by Sarasota Operations Coastal Oceans Observation Lab (SO COOL) that is using technology to track harmful algal blooms (HABs). Autonomous underwater vehicles (AUVs) are equipped with temperature and salinity meters as well as a "Breve-buster," which is an instrument that collects water samples and determines levels of red-tide causing algae by shining a light through the sample and noting the light absorbing characteristics within the sample (indicative of these algae).

Donald, David

2009-07-03

296

Weather Camp 2012 "Weather and Climate All Around Us"  

E-print Network

Weather Camp 2012 "Weather and Climate All Around Us" Are you interested in the weather? Come to Weather Camp at UNL What is Weather Camp? For more information Weather camp is a week long day camp for students who will be 11-14 years old at the time of the camp Most of the activities at Weather Camp 2012

Farritor, Shane

297

Interactive Weather Information Network  

NSDL National Science Digital Library

Offered by the National Oceanic and Atmospheric Administration (NOAA), the Interactive Weather Information Network (IWIN) is a collection of interactive weather maps and satellite images that is updated every five seconds. Visitors can see cloud cover animation loops, NEXRAD Radar images of precipitation, a map of all current weather fronts, and an interactive national map to see information about any particular state. Other information on the site includes a listing of any active weather warnings, a link for world weather data, and more, making this a must-see site for all those users interested in the most current weather happenings anywhere.

2002-01-01

298

Pilot weather advisor  

NASA Technical Reports Server (NTRS)

The results of the work performed by ViGYAN, Inc., to demonstrate the Pilot Weather Advisor cockpit weather data system using a broadcast satellite communication system are presented. The Pilot Weather Advisor demonstrated that the technical problems involved with transmitting significant amount of weather data to an aircraft in-flight or on-the-ground via satellite are solvable with today's technology. The Pilot Weather Advisor appears to be a viable solution for providing accurate and timely weather information for general aviation aircraft.

Kilgore, W. A.; Seth, S.; Crabill, N. L.; Shipley, S. T.; Graffman, I.; Oneill, J.

1992-01-01

299

Edheads: Weather Activities  

NSDL National Science Digital Library

This great interactive resource allows you multiple opportunities to explore weather related concepts. After clicking start, you will learn how to report and predict the weather at the underground W.H.E.D weather caves! Each activity has three different levels, and each level is harder than the one before it. This resource also includes a teacher's guide (with pre- and post- tests) and links to additional weather related resources. These include a weather glossary, a Fahrenheit to Celsius & Celsius to Fahrenheit converter, and a link that provides information about interesting people in the weather field.

2010-01-01

300

Mean winds, tides and gravity waves in the upper middle atmosphere during ALOHA-90  

SciTech Connect

Wind measurements made with a partial reflection radar located on Christmas Island (2{degree}N, 157{degree}W) are used to describe the dynamical state of the equatorial mesopause region during ALOHA-90. Time mean westward (easterly) winds prevailed at most heights, and reached their maximum values of about {minus}60 ms{sup {minus}1} near 85 km, but the mean meridional motions were weak. Strong oscillations due to the 24, 12, and 8 hr atmospheric tides were also observed in both wind components. The inferred vertical wavelengths were large, even for the diurnal tide. On the nights of 22 and 25 March, when airborne lidar observations were made in the vicinity of Christmas Island, the prevailing and tidal winds combined to produce especially strong westward winds ({minus}100 ms{sup {minus}1}). Gravity wave activity was also high during March/April, especially for short period waves, although considerable day-to-day variability was noted.

Vincent, R.A.; Lesicar, D. (Univ. of Adelaide (Australia))

1991-07-01

301

Exploring a Red Tide Incubator in Monterey Bay  

Microsoft Academic Search

There is growing evidence that a global increase in red tide blooms is occurring. Red tides can dramatically affect the structure and function of shelf sea ecosystems as well as compromise economies that depend on coastal resources. During the summer of 2007 weekly research cruises conducted in situ Underway mapping surveys along a transect in the northeast corner of Monterey

Shaun A. Rudolph; John Ryan; Erich Rienecker

302

Impact of sea level rise on tide gate function.  

PubMed

Sea level 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 sea level 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 sea level elevations on the tide gate's ability to prevent upstream flooding. Model predictions indicate that sea level 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 sea level 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. PMID:23379951

Walsh, Sean; Miskewitz, Robert

2013-01-01

303

Observed tides on the Northeastern Bering Sea shelf  

Microsoft Academic Search

Bottom pressure observations (November 1981 to August 1982) show that the diurnal tides dominate the outer reaches of the northeastern Bering Sea shelf. The diurnal tides decrease inshore from the shelf break (maximum K1 amplitude of 38 cm) and appear to be evanescent Sverdrup (Poincaré) waves on the outer shelf. The K1 amplitude (2.3 cm) in the Bering Strait is

Harold O. Mofjeld

1986-01-01

304

Coherence of internal tide modulations along the Hawaiian Ridge  

Microsoft Academic Search

Long time series of sea level from tide gauges along the north side of the Hawaiian Ridge and shorter series of dynamic heights inferred from inverted echo sounders moored just north of the main Hawaiian Islands are examined for evidence of internal tides at the M2 frequency. We find that the amplitudes and phases of the M2 tidal components have

Gary T. Mitchum; Stephen M. Chiswell

2000-01-01

305

TIDE-TSUNAMI INTERACTIONS Zygmunt Kowalik, Tatiana Proshutinsky,  

E-print Network

with amplitude 0.24 m, the next constituent K1 of mixed luni-solar origin has amplitude 0.14 m. 2 TABLE 1TIDE-TSUNAMI INTERACTIONS Zygmunt Kowalik, Tatiana Proshutinsky, Institute of Marine Science in the coastal regions and related to interaction with tides. Observations and computations of the Indian Ocean

Kowalik, Zygmunt

306

Barotropic and baroclinic tides in Philippine seas - a modeling study  

Microsoft Academic Search

A Regional Ocean Modeling System (ROMS) is applied in Sulu sea and its adjacent waters to look at the barotropic and baroclinic tides. The model is initialized from results of global HYbrid Coordinate Ocean Model (HYCOM). Surface forcing from the Navy's Operational Global Atmospheric Prediction System Model is prescribed. The barotropic tide and tidal current from OSU Tidal Prediction Software

B. Zhang; E. Curchitser; J. Levin; H. Arango

2008-01-01

307

Secular Changes in the Tide of the Gulf of Maine  

Microsoft Academic Search

For the past century the amplitude of the principal semidiurnal lunar tide in the Gulf of Maine has been dramatically increasing. For example, at Eastport, Maine, the trend in M2 amplitude is 13 cm\\/century, comparable to the rise in mean sea level. At the same time the solar tide S2 has been decreasing. These tidal changes, which occur throughout the

R. D. Ray

2008-01-01

308

Tide observations in the Korea-Tsushima Strait  

Microsoft Academic Search

Tides are analyzed in the Korea-Tsushima Strait using measurements from 11 moorings, each containing an acoustic Doppler current profiler (ADCP) and a pressure gauge. These instruments were bottom moored at depths ranging from 59 to 142 m from May 1999 until October 1999 along two lines across the Strait, northeast and southwest of Tsushima Island. Tide amplitudes range over 3

W. J. Teague; H. T. Perkins; G. A. Jacobs

2001-01-01

309

Current and tide observations in the southern Yellow Sea  

Microsoft Academic Search

Determination of mean currents and tides are particularly difficult in coastal regions. Flows are often nongeostrophic and short lived. Bathymetry is frequently not adequately known and can greatly influence coastal dynamics. To better quantify tides and currents in the southern Yellow Sea, three pressure gauges and three acoustic Doppler current profilers (ADCPs) were bottom moored for 4-6 month intervals at

W. J. Teague; H. T. Perkins; Z. R. Hallock; G. A. Jacobs

1998-01-01

310

DEVELOPMENT AND EVALUATION OF A RUBBER "DUCK BILL" TIDE GATE  

EPA Science Inventory

A unique 54 in. diameter "duckbill" rubber tide gate (RTG) was designed, fabricated, and installed in a typical New York City tide gate chamber. The operation of the RTG was observed over two years. The RTG was very effective in preventing the inflow of tidal waters and generally...

311

Effects of tides on deltaic deposition: Causes and responses  

Microsoft Academic Search

This paper explores the response of deltas to tidal reworking and discusses the conditions at which deltas may become strongly tide influenced or tide dominated. Three case studies are presented, from the Cretaceous Western Interior, the Devonian Baltic Basin and the Eocene Central Basin of Spitsbergen. All datasets contain extensive outcrop data, the Baltic Basin dataset also extensive core data.The

Piret Plink-Björklund

312

Climate Change and Extreme Weather  

NSDL National Science Digital Library

This module discusses how a changing climate can also lead to changes in extreme weather events on the local scale. The role of natural variability is also explained. The module describes how climate change can have both positive and negative effects, depending on the situation, location, and the vulnerability of the population. While research on climate change and extreme events is still relatively new, the module discusses what changes scientists think are likely if greenhouse gas emissions continue to rise.

Comet

2012-08-14

313

The effects of low-tide rainfall on metal content of suspended sediment in the Sacramento-San Joaquin Delta  

NASA Astrophysics Data System (ADS)

Rain falling near low tide is capable of eroding and transporting cohesive sediment from marsh and mudflat surfaces. Given that metals adsorb strongly to silt- and clay-sized particles, it is conceivable that lowtide rainfall may also liberate previously-deposited metals from storage in intertidal sediment. To investigate the potential for rainfall as an agent of remobilization of metals, this study tested the hypothesis of sediment, and therefore metals and nutrients, mobilization during these punctuated low-tide rainfall events. Water samples were collected during low-tide rain events in winter and wind resuspension events in summer from a marsh in central California. The concentrations of suspended sediment, particulate organic carbon and nitrogen, and total adsorbed concentration (mass of metal per volume of filtered water) of most metals were higher during a low tide rainfall event than during wind-only and fair-weather events. Metal contents (mass of metal per mass of sediment) were also greater during the rain event for most metals. Principle components analysis and the relationships between total adsorbed metals and SSC suggest rainfall during low tide can mobilize a different source of sediment than the background sediment available for tidal and wind-wave resuspension. The metal content of bulk sediment samples from around the study area could not be matched satisfactorily to the suspended sediment in any of the events, implying that bulk sediment should not be used to extrapolate to suspended sediment in terms of adsorbed metal content. Some of the adsorbed metals were present during the rain event in amounts that could be toxic, depending on the actual bioavailability of the metals.; Summary plots of measured organic parameters. (A) POC (B) PN (C) C:N (D) total leachable metal concentration, sum of all measured metals. The solid line inside box is the median and the dashed line is the mean.

Moskalski, S. M.; Torres, R.; Bizimis, M.; Bergamaschi, B. A.; Fleck, J.; Goni, M. A.

2012-12-01

314

[Study of red tide spectral characteristics and its mechanism].  

PubMed

In situ spectral data of different red tide, whose dominant species are leptocylindrus danicus, chattonella marina, skeletonema costatum, and mesodinium rubrum, were acquired by above water method utilizing spectrometer manufactured by FieldSpec Dual VNIR (USA). It is emphasized that the characteristic reflectance peak lying between 687 and 728 nm can be used to distinguish between red tide and normal sea water. Also the spectral discrepancy between different dominant species of red tide is pointed out, which could be utilized to identify certain red tide species by remote sensing technique. Mechanisms of phytoplankton red tide spectra peaks and vales are given. Spectral characteristics of mesodinium rubrum, a kind of protozoan, may be related to its symbiotic alga in its body and phytoplankton pigment crumb. So, research on ingestion preference, symbiotic property with algae, and fluorescence emission character of such symbiotic algae under normal temperature may be helpful for the deep understanding of mechanism of mesodinium rubrum spectra. PMID:16883860

Cui, Ting-Wei; Zhang, Jie; Ma, Yi; Sun, Ling

2006-05-01

315

Diurnal tides at low latitudes: Radar, satellite, and model results  

NASA Astrophysics Data System (ADS)

Mean winds and tidal signatures in the mesosphere and lower thermosphere (MLT) region are derived from meteor radar observations at three sites around 22°S acquired in 2005. The observed differences of mean winds and tides are discussed in relation to the meteorological situation in the lower atmosphere and the possible generation of non-migrating tides. The longitudinally well separated radar sites allowed the evaluation of the migrating tidal component. The seasonal variation of signatures of the diurnal tide derived from ground-based radar observations, TIDI measurements aboard TIMED satellite, and model results obtained with HAMMONIA (Hamburg Model of the Neutral and Ionized Atmosphere) are compared. The ground-based, satellite, and model results of the total diurnal tide are in good agreement. The same is true for the migrating diurnal tide obtained from the radar observations, TIDI observations and from the model studies of HAMMONIA and GSWM00 (Global Scale Wave Model).

Kishore Kumar, G.; Singer, W.; Oberheide, J.; Grieger, N.; Batista, P. P.; Riggin, D. M.; Schmidt, H.; Clemesha, B. R.

2014-10-01

316

On Observing the Weather  

NSDL National Science Digital Library

In this article, Mount Washington Observatory meteorologist Tim Markle shares the ins and outs of his daily weather-observing routine and offers insights on making weather observations at home or at school.

Crane, Peter

2004-05-01

317

Favorite Demonstration: Differential Weathering  

NSDL National Science Digital Library

In this inquiry-based demonstration, the consumption of a Baby Ruth candy bar is used to nurture students' interest in chemical and physical weathering. In addition, two other concepts can be illustrated: the difference between weathering and erosion and

Francek, Mark

2002-10-01

318

Owlie Skywarn's Weather Book  

NSDL National Science Digital Library

This is an online activity book from the National Weather Service that teaches about hazardous weather. The site also includes links to kids sites for the Federal Emergency Management Agency (FEMA) and the National Oceanic and Atmospheric Agency (NOAA).

Garcia, Cris; Davis, Steve

2001-06-22

319

Weather in Antarctica  

NSDL National Science Digital Library

This homepage includes information about the weather in Antarctica and links to pages on the climate, wind chill, clouds, snow and ice, and pressure and storms of Antarctica. The current weather conditions updated automatically at various stations are also provided.

Hutchings, Thomas

1998-01-01

320

Winter Weather Emergencies  

MedlinePLUS

Severe winter weather can lead to health and safety challenges. You may have to cope with Cold related health problems, including ... there are no guarantees of safety during winter weather emergencies, you can take actions to protect yourself. ...

321

Weather Camp 2012: Weather and Climate All Around Us Are you interested in the weather?  

E-print Network

Weather Camp 2012: Weather and Climate All Around Us Are you interested in the weather? Come to Weather Camp at UNL! What is Weather Camp? For more information Weather camp is a week-long day camp for students who will be 11-14 years old at the time of the camp. Most of the activities at Weather Camp 2012

Farritor, Shane

322

Weather and Road Management  

NSDL National Science Digital Library

Anticipating and dealing with weather and the hazards it creates is a real challenge for those in departments of transportation. This module gives road and highway managers a basic understanding of meteorology and weather hazards so that they can better interpret weather forecast information used to make road management decisions. The module also highlights web-based forecast products available from the National Weather Service that can help in the decision-making process.

Comet

2008-07-21

323

Stormfax Weather Services  

NSDL National Science Digital Library

This site offers links to a variety of weather information, including national, international and local weather maps and forecasts, satellite and radar imagery, and severe weather warnings. There are also links to diverse resources such as fire maps, glacier inventories, snow depths, storm surges and tropical storms. There are reports and advisories about El Nino and La Nina. The site also has a glossary of weather terms and conversion charts for temperature, wind speed and atmospheric pressure.

2002-06-10

324

Enviropedia: Introduction to Weather  

NSDL National Science Digital Library

This resource provides an overview of weather, the day-to-day changes in temperature, air pressure, moisture, wind, cloudiness, rainfall and sunshine. Links embedded in the text provide access to descriptions of cloud types and to information on weather hazards such as fog, hurricanes, thunderstorms, and tornadoes. Other topics include meteorology, weather measurements, and weather mapping. Materials are also provided on the water cycle and its elements, such as evaporation, uplift and cooling of air, dew point, condensation, and precipitation.

2007-12-12

325

Fire Weather Climatology  

NSDL National Science Digital Library

The âFire Weather Climatologyâ module provides a comprehensive look at fire regions across the United States and characteristics of typical fire seasons in each region. In addition, critical fire weather patterns are described in terms of their development, duration and impact on fire weather. Numerous case studies provide examples and opportunities to practice recognizing these critical patterns and how they can affect fire ignition and spread. This module is part of the Advanced Fire Weather Forecasters Course.

Comet

2008-04-28

326

Global ocean tides. Part V. The diurnal principal lunar tide (O1), atlas of tidal charts and maps. Final report  

Microsoft Academic Search

In Part I of this report (AD-A060 913), a unique hydrodynamical interpolation technique was introduced, extensively tested, and evaluated in order to compute partial global ocean tides in great detail and with a high degree of accuracy. This novel method has been applied to construct the diurnal principal lunar (O1) ocean tide with a relative accuracy of better than 5

Schwiderski

1981-01-01

327

Weather Theory Introduction  

E-print Network

11-1 Weather Theory Chapter 11 Introduction Weather is an important factor that influences aircraft), visibility (clearness or cloudiness), and barometric pressure (high or low). The term weather can also apply of the atmosphere. Atmosphere The atmosphere is a blanket of air made up of a mixture of gases that surrounds

328

American Weather Stories.  

ERIC Educational Resources Information Center

Weather has shaped United States' culture, national character and folklore; at times it has changed the course of history. The seven accounts compiled in this publication highlight some of the nation's weather experiences from the hurricanes that threatened Christopher Columbus to the peculiar run of bad weather that has plagued American…

Hughes, Patrick

329

Predicting Seasonal Weather  

NSDL National Science Digital Library

This module is about a new method of predicting seasonal weather. The site describes the effects of El Nino on global weather and the accuracy of the new model. It includes links to classroom resources for a variety of weather-based units.

Dybas, Cheryl

2008-12-07

330

Extreme Weather on Earth  

NSDL National Science Digital Library

In this activity, students utilize a set of photographs and a 30 minute video on weather to investigate extreme weather events. They are posed with a series of questions that ask them to identify conditions predictive of these events, and record them on a worksheet. Climate and weather concepts defined.

Mika, Anna; Education, National G.

331

Space Weather Now  

NSDL National Science Digital Library

The Space Weather Now page is intended to give the non-technical user a "plain language" look at space weather. It includes information about relevant events and announcements, data from and about different instruments and satellites watching various aspects of space weather, alerts and advisories, daily themes of products and services, and links appropriate for the various groups of users.

Center, Space E.; Service, National O.

332

Climate and Weather  

NSDL National Science Digital Library

This video discusses the differences between climate and weather by defining and presenting examples of each. When presenting examples of weather, the video focuses on severe events and how meteorologists predict and study the weather using measurement, satellites, and radar. The climate focus is primarily on an overview of climate zones.

Geographic, National

333

METEOROLOGICAL Weather and Forecasting  

E-print Network

AMERICAN METEOROLOGICAL SOCIETY Weather and Forecasting EARLY ONLINE RELEASE This is a preliminary and interpretation of information from National Weather Service watches and warnings by10 decision makers such an outlier to the regional severe weather climatology. An analysis of the synoptic and13 mesoscale

334

Winter Weather Introduction  

E-print Network

Winter Weather Management #12;Introduction · Campus Facilities Staff · Other Campus Organizations #12;Purpose · Organize and coordinate the campus response to winter weather events to maintain campus for use by 7 AM. · Response will be modified depending upon forecast and current weather conditions. #12

Taylor, Jerry

335

Intelligent weather agent for aircraft severe weather avoidance  

E-print Network

avoidance capability has increased. In this thesis, an intelligent weather agent is developed for general aviation aircraft. Using a radar image from an onboard weather radar, the intelligent weather agent determines the safest path around severe weather...

Bokadia, Sangeeta

2012-06-07

336

Convective Weather Avoidance with Uncertain Weather Forecasts  

NASA Technical Reports Server (NTRS)

Convective weather events have a disruptive impact on air traffic both in terminal area and in en-route airspaces. In order to make sure that the national air transportation system is safe and efficient, it is essential to respond to convective weather events effectively. Traffic flow control initiatives in response to convective weather include ground delay, airborne delay, miles-in-trail restrictions as well as tactical and strategic rerouting. The rerouting initiatives can potentially increase traffic density and complexity in regions neighboring the convective weather activity. There is a need to perform rerouting in an intelligent and efficient way such that the disruptive effects of rerouting are minimized. An important area of research is to study the interaction of in-flight rerouting with traffic congestion or complexity and developing methods that quantitatively measure this interaction. Furthermore, it is necessary to find rerouting solutions that account for uncertainties in weather forecasts. These are important steps toward managing complexity during rerouting operations, and the paper is motivated by these research questions. An automated system is developed for rerouting air traffic in order to avoid convective weather regions during the 20- minute - 2-hour time horizon. Such a system is envisioned to work in concert with separation assurance (0 - 20-minute time horizon), and longer term air traffic management (2-hours and beyond) to provide a more comprehensive solution to complexity and safety management. In this study, weather is dynamic and uncertain; it is represented as regions of airspace that pilots are likely to avoid. Algorithms are implemented in an air traffic simulation environment to support the research study. The algorithms used are deterministic but periodically revise reroutes to account for weather forecast updates. In contrast to previous studies, in this study convective weather is represented as regions of airspace that pilots are likely to avoid. The automated system periodically updates forecasts and reassesses rerouting decisions in order to account for changing weather predictions. The main objectives are to reroute flights to avoid convective weather regions and determine the resulting complexity due to rerouting. The eventual goal is to control and reduce complexity while rerouting flights during the 20 minute - 2 hour planning period. A three-hour simulation is conducted using 4800 flights in the national airspace. The study compares several metrics against a baseline scenario using the same traffic and weather but with rerouting disabled. The results show that rerouting can have a negative impact on congestion in some sectors, as expected. The rerouting system provides accurate measurements of the resulting complexity in the congested sectors. Furthermore, although rerouting is performed only in the 20-minute - 2-hour range, it results in a 30% reduction in encounters with nowcast weather polygons (100% being the ideal for perfectly predictable and accurate weather). In the simulations, rerouting was performed for the 20-minute - 2-hour flight time horizon, and for the en-route segment of air traffic. The implementation uses CWAM, a set of polygons that represent probabilities of pilot deviation around weather. The algorithms were implemented in a software-based air traffic simulation system. Initial results of the system's performance and effectiveness were encouraging. Simulation results showed that when flights were rerouted in the 20-minute - 2-hour flight time horizon of air traffic, there were fewer weather encounters in the first 20 minutes than for flights that were not rerouted. Some preliminary results were also obtained that showed that rerouting will also increase complexity. More simulations will be conducted in order to report conclusive results on the effects of rerouting on complexity. Thus, the use of the 20-minute - 2-hour flight time horizon weather avoidance teniques performed in the simulation is expected to provide benefits for short-term weather avoidan

Karahan, Sinan; Windhorst, Robert D.

2009-01-01

337

Semidiurnal internal tides in a Patagonian Fjord  

NASA Astrophysics Data System (ADS)

The fjords of central Chilean Patagonia (47 °S) receive input of fresh water from precipitation (˜2500 m3) and from the Baker River (˜900 m3 s-1). This buoyancy input generates a two layer hydrographic system characterized by strong salinity stratification (~30 g/kg over a depth range of 7-15 m), which drives baroclinic circulation. Hourly current velocity profiles were collected with an ADCP mooring at a depth of 40 m during March-April 2009. Data allowed, for the first time, the detection of semidiurnal internal tidal waves that traveled near the pycnocline with a maximum wavelength of 2400 km at ~8 m depth and with horizontal phase speed of ~0.55 m s-1. Harmonic, wavelet, and EOF analysis techniques applied to the echo anomaly signal and to the baroclinic velocity, showed largest semidiurnal amplitudes near the pycnocline and the first three dominant modes of the EOF described a two-layer flow structure. The semidiurnal internal waves were found in sporadic packets as fluctuations near the pycnocline. High correlation values (r2=0.67) suggest that semidiurnal internal tides in this region were related to high discharge pulses of the Baker River. Also, the internal wave propagation angle (? = 87°) suggests that pulses in river discharge, rather than interaction of barotropic tide with bathymetry (a sill), modulate these internal tides, which is also a novel finding. The vertical modulation of the pycnocline triggers undulations that may enhance mixing through shear instabilities at the wave interface. This mixing mechanism is likely the main transporter of nutrients from deep waters toward the surface, which favors primary production. The Baker River may be dramatically altered through damming and reducing the freshwater supply to channels and fjords. Damming then could impact mixing mechanisms and modify the local fjord ecosystem. Future work needs to concentrate on determining the effect of wind, which is believed to be related to the major variance in mode 1 (62.6%) of the echo anomaly signal. This mode showed dominance of diurnal fluctuations.

Ross, L.; Perez, I.; Valle-Levinson, A.

2013-05-01

338

Model estimates of the contribution of atmospheric lunar tides to the formation of global meteorological processes in the Earth troposphere  

NASA Astrophysics Data System (ADS)

A numerical linearized thermohydrodynamic model of generation and formation of global growing tropospheric disturbances caused by atmospheric lunar tides is developed. The model allows calculating unstable disturbances of pressure, density, temperature and wind speed at grid points of the numerical model from height and latitude, as well as from time since the model is also nonstationary. As numerical experiments showed, the unstable solutions obtained are exponentially increasing in time, which is due to vertical and horizontal temperature gradients that are included in the model’s input parameters and whose values agree with experimental data. In numerical experiments, atmospheric lunar tides act as regular disturbances. By using numerical modeling with the model developed, it is shown that slight atmospheric lunar tides can initiate significant global disturbances of temperature, pressure, density and wind speed in the troposphere of the two hemispheres. The amplitude of these disturbances is two or three orders of magnitude larger than that of the atmospheric lunar tides. The analysis of the results obtained allows classifying increasing solutions in terms of geophysical hydrodynamics. These solutions can be referred to either solutions for inertial waves (that are similar to two-dimensional Rossby waves) or solutions for internal (three-dimensional) inertial waves. The altitude-latitude isolines of meridional stream functions of increasing unsteady solutions clearly showed that global disturbances initiating atmospheric lunar tides represent a chain of toroidal (Tailor) vortices meridionally, i.e. from one pole to the other, located in the troposphere. Characteristic time of the increase in disturbances amplitude varies from 80 hours in winter to 120 hours in summer. The periods of global disturbances are about 15 days in winter and increase to 30 days in summer. From the results obtained, we can conclude that atmospheric tides are to be taken into account in numerical models of medium and long-range weather forecasts. References. A.A. Gavrilov. Tropospheric and lower-stratospheric zonal circulation disturbances produced by atmospheric lunar tides. In: Physical Problems of Ecology, Moscow State University, Moscow, Max-Press, 2013, ?.19, pp.142-152.

Gavrilov, Anatoliy A.; Pokazeyev, Konstantin V.

339

Terminal weather information management  

NASA Technical Reports Server (NTRS)

Since the mid-1960's, microburst/windshear events have caused at least 30 aircraft accidents and incidents and have killed more than 600 people in the United States alone. This study evaluated alternative means of alerting an airline crew to the presence of microburst/windshear events in the terminal area. Of particular interest was the relative effectiveness of conventional and data link ground-to-air transmissions of ground-based radar and low-level windshear sensing information on microburst/windshear avoidance. The Advanced Concepts Flight Simulator located at Ames Research Center was employed in a line oriented simulation of a scheduled round-trip airline flight from Salt Lake City to Denver Stapleton Airport. Actual weather en route and in the terminal area was simulated using recorded data. The microburst/windshear incident of July 11, 1988 was re-created for the Denver area operations. Six experienced airline crews currently flying scheduled routes were employed as test subjects for each of three groups: (1) A baseline group which received alerts via conventional air traffic control (ATC) tower transmissions; (2) An experimental group which received alerts/events displayed visually and aurally in the cockpit six miles (approx. 2 min.) from the microburst event; and (3) An additional experimental group received displayed alerts/events 23 linear miles (approx. 7 min.) from the microburst event. Analyses of crew communications and decision times showed a marked improvement in both situation awareness and decision-making with visually displayed ground-based radar information. Substantial reductions in the variability of decision times among crews in the visual display groups were also found. These findings suggest that crew performance will be enhanced and individual differences among crews due to differences in training and prior experience are significantly reduced by providing real-time, graphic display of terminal weather hazards.

Lee, Alfred T.

1990-01-01

340

External Resource: Weathering and Erosion  

NSDL National Science Digital Library

This activity includes background information about weathering, as well as simple demonstrations/activities to model how weather conditions contribute to weathering and erosion. Topics include: chemical weathering, dunes, erosion, floods, glaciers, physi

1900-01-01

341

Plymouth State Weather Center  

NSDL National Science Digital Library

The Plymouth State Weather Center provides a variety of weather information, including a tropical weather menu with current and archived data on tropical depressions, storms, or hurricanes in the Atlantic or Eastern Pacific Oceans. An interactive Weather Product Generator allows students to make their own surface data maps and meteograms (24-hour summaries of weather at a specific location), and view satellite imagery. There are also interactive weather maps for the U.S., Canada, and Alaska that display the latest observations, and text servers which provide current written observations for New England and North America. A set of past and current weather data products provides information on minimum and maximum temperatures, wind chill, and heat index. In addition, there are collections of satellite loops/movies, radar/lightning images, loops, and movies, and a set of tutorials on clouds, the sun and its effects on the environment, and balanced atmospheric flows.

342

Avalanche Weather Forecasting  

NSDL National Science Digital Library

Avalanches form through the interaction of snowpack, terrain, and weather, the latter being the focus of this module. The module begins with basic information about avalanches, highlighting weather's role in their development. The rest of the module teaches weather forecasters how to make an avalanche weather forecast, that is, one in which key weather parameters are evaluated for their impact on avalanche potential. The forecasts are used primarily by avalanche forecasters, who integrate them with other information to determine when to issue avalanche hazard warnings. The module contains five cases that let users apply the avalanche weather forecast process to different combinations of snowpack, terrain, and weather conditions. It is a companion to the COMET module "Snowpack and Its Assessment," which describes snowpack development and various assessment techniques.

Comet

2010-09-30

343

Beyond the Weather Chart: Weathering New Experiences.  

ERIC Educational Resources Information Center

Describes an early childhood educator's approach to teaching children about rain, rainbows, clouds, precipitation, the sun, air, and wind. Recommends ways to organize study topics and describes experiments that can help children better understand the different elements of weather. (MOK)

Huffman, Amy Bruno

1996-01-01

344

Fortnightly Earth rotation, ocean tides and mantle anelasticity  

NASA Astrophysics Data System (ADS)

This study of the fortnightly Mf tide comprises three main topics: (1) a new determination of the fortnightly component of polar motion and length of day (LOD) from a multidecade time-series of observed space-geodetic data; (2) the use of the polar motion determination as one constraint in the development of a hydrodynamic ocean model of the Mf tide and (3) the use of these results to place new constraints on mantle anelasticity at the Mf tidal period. Our model of the Mf ocean tide assimilates more than 14 years of altimeter data from the Topex/Poseidon and Jason-1 satellites. Because the Mf altimetric signal-to-noise ratio is very small, it is critical that altimeter data not be overweighted. The polar motion data, plus tide-gauge data and independent altimeter data, give useful additional information, with only the polar motion putting constraints on tidal current velocities. The resulting ocean-tide model, plus the dominant elastic body tide, leaves a small residual in observed LOD caused by mantle anelasticity. The inferred effective tidal Q of the anelastic body tide is 90 and is in line with a ?? frequency dependence with ? in the range 0.2-0.3.

Ray, Richard D.; Egbert, Gary D.

2012-04-01

345

Of Yo-Yos, the PIG and Tides  

NASA Astrophysics Data System (ADS)

The rapid melting of the Pine Island Glacier (PIG) has been attributed to ocean melting. Specifically, this ocean melting is attributed to currents and tides pumping Circumpolar Deep Water (CDW) into the ice shelf cavity. To illuminate the role of tides in the melting of the PIG and the circulation and mixing at the ice shelf front, a time series of yo-yo CTD (Conductivity, Temperature, and Depth) data collected in the PIG outflow region was analyzed. The water column in the region consisted of two primary layers, a meltwater layer exiting the ice shelf cavity over a layer of CDW. Semidiurnal tides were present in both layers, with both the strength and direction of the tides differing between the two layers. The upper layer tides were stronger and directed in and out of the cavity, while the lower layer tides were primarily directed along the front of the cavity. The upper layer consisted of two meltwater layers. In the uppermost of these layers, waves with a semidiurnal frequency were propagating downward at a speed consistent with the M2 tide with the stratification. Energy was found to be transferred from the semidiurnal tide to other frequencies and to be reflected from the ice shelf front. These mechanisms were most prominent at the interfaces between layers and indicate potential mixing between the layers. In conclusion, tides were found to contribute to the circulation into the ice shelf cavity and also to mixing of the exiting water, which influences pumping of the CDW into the ice shelf cavity and melting of the PIG.

Robertson, R.

2009-12-01

346

Bifurcation analysis of brown tide by reaction-diffusion equation using finite element method  

SciTech Connect

In this paper, we analyze the bifurcation of a biodynamics system in a two-dimensional domain by virtue of reaction-diffusion equations. The discretization method in space is the finite element method. The computational algorithm for an eigenspectrum is described in detail. On the basis of an analysis of eigenspectra according to Helmholtz`s equation, the discrete spectra in regards to the physical variables are numerically obtained in two-dimensional space. In order to investigate this mathematical model in regards to its practical use, we analyzed the stability of two cases, i.e., hydranth regeneration in the marine hydroid Tubularia and a brown tide in a harbor in Japan. By evaluating the stability according to the linearized stability definition, the critical parameters for outbreaks of brown tide can be theoretically determined. In addition, results for the linear combination of eigenspectrum coincide with the distribution of the observed brown tide. Its periodic characteristic was also verified. 10 refs., 8 figs., 5 tabs.

Kawahara, Mutsuto; Ding, Yan [Chuo Univ., Tokyo (Japan)] [Chuo Univ., Tokyo (Japan)

1997-03-01

347

Solar and lunar tides in the geomagnetic field  

Microsoft Academic Search

Amplitudes of spectral geomagnetic field components and signal\\/noise ratios are estimated at frequencies of lunar and solar\\u000a tides based on the data registered at the experimental site of Vladimir State University (VlSU) and Japanese geomagnetic stations\\u000a Kakioka (1913–2006) and Memambetsu (1950–1999). The influence of thermal solar tides S1, S2, S3, and S4 and lunar gravitational\\u000a tides O1, M2, and N2

L. V. Grunskaya; V. N. Morozov; A. A. Zakirov; D. V. Rubai; R. V. Rubai

2011-01-01

348

Observation of ocean tides below the Filchner and Ronne Ice Shelves, Antarctica, using synthetic aperture radar interferometry: Comparison with tide model predictions  

NASA Astrophysics Data System (ADS)

Tides near and under floating glacial ice, such as ice shelves and glacier termini in fjords, can influence heat transport into the subice cavity, mixing of the under-ice water column, and the calving and subsequent drift of icebergs. Free-surface displacement patterns associated with ocean variability below glacial ice can be observed by differencing two synthetic aperture radar (SAR) interferograms, each of which represents the combination of the displacement patterns associated with the time-varying vertical motion and the time-independent lateral ice flow. We present the pattern of net free-surface displacement for the iceberg calving regions of the Ronne and Filchner Ice Shelves in the southern Weddell Sea. By comparing SAR-based displacement fields with ocean tidal models, the free-surface displacement variability for these regions is found to be dominated by ocean tides. The inverse barometer effect, i.e., the ocean's isostatic response to changing atmospheric pressure, also contributes to the observed vertical displacement. The principal value of using SAR interferometry in this manner lies in the very high lateral resolution (tens of meters) obtained over the large region covered by each SAR image. Small features that are not well resolved by the typical grid spacing of ocean tidal models may contribute to such processes as iceberg calving and cross-frontal ventilation of the ocean cavity under the ice shelf.

Rignot, E.; Padman, L.; MacAyeal, D. R.; Schmeltz, M.

349

Weather and Atmosphere  

NSDL National Science Digital Library

In this unit, students learn the basics about weather and the atmosphere. They investigate materials engineering as it applies to weather and the choices available to us for clothing to counteract the effects of weather. Students have the opportunity to design and analyze combinations of materials for use in specific weather conditions. In the next lesson, students also are introduced to air masses and weather forecasting instrumentation and how engineers work to improve these instruments for atmospheric measurements on Earth and in space. Then, students learn the distinguishing features of the four main types of weather fronts that accompany high and low pressure air masses and how those fronts are depicted on a weather map. During this specific lesson, students learn different ways that engineers help with storm prediction, analysis and protection. In the final lesson, students consider how weather forecasting plays an important part in their daily lives by learning about the history of weather forecasting and how improvements in weather technology have saved lives by providing advance warning of natural disasters.

Integrated Teaching And Learning Program

350

Space Weathering of Rocks  

NASA Technical Reports Server (NTRS)

Space weathering discussions have generally centered around soils but exposed rocks will also incur the effects of weathering. On the Moon, rocks make up only a very small percentage of the exposed surface and areas where rocks are exposed, like central peaks, are often among the least space weathered regions we find in remote sensing data. However, our studies of weathered Ap 17 rocks 76015 and 76237 show that significant amounts of weathering products can build up on rock surfaces. Because rocks have much longer surface lifetimes than an individual soil grain, and thus record a longer history of exposure, we can study these products to gain a deeper perspective on the weathering process and better assess the relative impo!1ance of various weathering components on the Moon. In contrast to the lunar case, on small asteroids, like Itokowa, rocks make up a large fraction of the exposed surface. Results from the Hayabusa spacecraft at Itokowa suggest that while the low gravity does not allow for the development of a mature regolith, weathering patinas can and do develop on rock surfaces, in fact, the rocky surfaces were seen to be darker and appear spectrally more weathered than regions with finer materials. To explore how weathering of asteroidal rocks may differ from lunar, a set of ordinary chondrite meteorites (H, L, and LL) which have been subjected to artificial space weathering by nanopulse laser were examined by TEM. NpFe(sup 0) bearing glasses were ubiquitous in both the naturally-weathered lunar and the artificially-weathered meteorite samples.

Noble, Sarah

2011-01-01

351

NOAA Daily Weather Maps  

NSDL National Science Digital Library

The charts on this website are the principal charts of the former Weather Bureau publication, "Daily Weather Map." They are the Surface Weather Map, the 500-Millibar Height Contours chart, the Highest and Lowest Temperatures chart, and the Precipitation Areas and Amounts chart. For each day, simple charts are arranged on a single page. These charts are the surface analysis of pressure and fronts, color shading, in ten degree intervals,of maximum and minimum temperature, 500-Millibar height contours, and color shaded 24-hour total precipitation. These charts act as links to their respective Daily Weather Map charts. All charts are derived from the operational weather maps prepared at the National Centers for Environmental Prediction, Hydrometeorological Prediction Center, National Weather Service.

Center, Hydrometeorological P.

2011-01-01

352

Molecular insights into the niche of harmful brown tides  

E-print Network

Recurrent brown tide blooms caused by the harmful alga Alureococcus anophagefferens have decimated coastal ecosystems and shellfisheries along the Eastern U.S and South Africa. The exact mechanisms controlling bloom ...

Wurch, Louie L. (Louie Lorne)

2011-01-01

353

Catching the Tide: A Review of Tidal Energy Systems  

ERIC Educational Resources Information Center

Harnessing energy from the tides is a much-promoted but rarely realised way of generating electricity. This article examines some of the systems that are currently in use or under development, and outlines their economic, environmental and technical implications.

Harris, Frank

2014-01-01

354

Increasing storm tides in New York Harbor, 1844-2013  

NASA Astrophysics Data System (ADS)

of the nine highest recorded water levels in the New York Harbor region have occurred since 2010 (March 2010, August 2011, and October 2012), and eight of the largest twenty have occurred since 1990. To investigate whether this cluster of high waters is a random occurrence or indicative of intensified storm tides, we recover archival tide gauge data back to 1844 and evaluate the trajectory of the annual maximum storm tide. Approximately half of long-term variance is anticorrelated with decadal-scale variations in the North Atlantic Oscillation, while long-term trends explain the remainder. The 10 year storm tide has increased by 0.28 m. Combined with a 0.44 m increase in local sea level since 1856, the 10 year flood level has increased by approximately 0.72 ± 0.25 m, and magnified the annual probability of overtopping the typical Manhattan seawall from less than 1% to about 20-25%.

Talke, S. A.; Orton, P.; Jay, D. A.

2014-05-01

355

Bermuda sea level in relation to tides, weather, and baroclinic fluctuations  

Microsoft Academic Search

The sea-level record over an 8-year period at the Biological Station, Bermuda, has been analyzed in an attempt to deduce the complete physics of sea-level variations in the frequency band of 1 cycle per 8 years to 0.5 cycles per hour. The admittance of the linear tidal lines was calculated, and, on the basis of certain assumptions about a linear

Carl Wunsch

1972-01-01

356

Weather and Climate Data  

NSDL National Science Digital Library

The Weather and Climate Data site for the Center for Ocean-Land-Atmosphere Studies (COLA) contains analyses of current conditions and the state of the atmosphere; weather forecasts; metropolitan quick-look weather summaries and meteograms; short-term climate outlooks for temperature, precipitation and soil moisture; El Nino forecasts for understanding the ocean-atmosphere system; and maximum potential hurricane intensity maps showing potential minimum pressure and potential maximum winds for the oceans.

357

Space Weather Media Viewer  

NSDL National Science Digital Library

This is version 3 of the space Weather Media Viewer, created to work with the space Weather Action Center to see near-real time data and to provide additional images and resources available for educational use. It features easy downloads that can also be added to news reports and space weather reports. It was designed for ease in adding any media (videos, images) data.

2011-01-01

358

Winter weather activity  

NSDL National Science Digital Library

This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Weather Maker Simulator Use the weather simulation above to answer the following questions in complete sentences on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What usually happens when there is a large difference between the temperatures? 4. What happens when there is high ...

Frankovic, Whitney

2009-09-28

359

Weather Radar Fundamentals  

NSDL National Science Digital Library

This 2-hour module presents the fundamental principles of Doppler weather radar operation and how to interpret common weather phenomena using radar imagery. This is accomplished via conceptual animations and many interactive radar examples in which the user can practice interpreting both radar reflectivity and radar velocity imagery. Although intended as an accelerated introduction to understanding and using basic Doppler weather radar products, the module can also serve as an excellent refresher for more experienced users.

Comet

2012-03-21

360

RBSP Space Weather data  

NASA Astrophysics Data System (ADS)

On August 23, 2012, NASA will launch two identical probes into the radiation belts to provide unprecedented insight into the physical processes and dynamics of near-Earth space. The RBSP mission in addition to the scientific data return, provides a 1Kbps real-time space weather broadcast data in support of real time space weather modeling, forecast and prediction efforts. Networks of ground stations have been identified to downlink the space weather data. The RBSP instrument suites have selected space weather data to be broadcast from their collected space data on board the spacecraft, a subset from measurements based on information normally available to the instrument. The data subset includes particle fluxes at a variety of energies, and magnetic and electric field data. This selected space weather data is broadcast at all times through the primary spacecraft science downlink antennas when an observatory is not in a primary mission-related ground contact. The collected data will resolve important scientific issues and help researchers develop and improve various models for the radiation belts that can be used by forecasters to predict space weather phenomena and alert astronauts and spacecraft operators to potential hazards. The near real-time data from RBSP will be available to monitor and analyze current environmental conditions, forecast natural environmental changes and support anomaly resolution. The space weather data will be available on the RBSP Science Gateway at http://athena.jhuapl.edu/ and will provide access to the space weather data received from the RBSP real-time space weather broadcast. The near real-time data will be calibrated and displayed on the web as soon as possible. The CCMC will ingest the RBSP space weather data into real-time models. The raw space weather data will be permanently archived at APL. This presentation will provide a first look at RBSP space weather data products.

Weiss, M.; Fox, N. J.; Mauk, B. H.; Barnes, R. J.; Potter, M.; Romeo, G.; Smith, D.

2012-12-01

361

WWW - Wonderful Web Weather  

NSDL National Science Digital Library

This is a web quest for students to research weather forecasting using the Internet. Students work in groups to study how accurate weather forecasts are by tracking the weather for 3 days in several locations. Using graphs students then compare how each location scored in accuracy and present their findings to the class. This site contains links for students to use for more background information, a process for the students to follow, and evaluation rubrics for the student-produced graphs and presentation.

Parrish, Jason

2007-12-12

362

Weather and climate  

NASA Technical Reports Server (NTRS)

Recommendations for using space observations of weather and climate to aid in solving earth based problems are given. Special attention was given to: (1) extending useful forecasting capability of space systems, (2) reducing social, economic, and human losses caused by weather, (3) development of space system capability to manage and control air pollutant concentrations, and (4) establish mechanisms for the national examination of deliberate and inadvertent means for modifying weather and climate.

1975-01-01

363

Detection of a Europan Ocean from Tides and Rotation  

Microsoft Academic Search

Europa's icy surface displays tectonic evidence of thin shell (<20km) dynamics while the predicted total depth of the ice-water layer is 80-140km from moment of inertia. Jupiter raises 20-30m periodic tide resulting from orbit eccentricity. This 3.55d tide can be detected from an orbiting spacecraft using altimetry (which measures Love number h2 and Doppler tracking (which observes the gravimetric k2

C. F. Yoder

2000-01-01

364

Internal tides and waves near the continental shelf edge  

Microsoft Academic Search

The subject is reviewed from the viewpoints of theory, internal tide and wave structure and their implications.A wider theoretical context suggests scope for further investigation of natural or nearly-trapped forms above the inertial frequency.Although internal tides in many locations are observed to have first-mode vertical structure, higher modes are seen offshore from shallow shelf-break forcing and for particular Froude numbers,

J. M. Huthnance

1989-01-01

365

Effects of Long Period Ocean Tides on the Earth's Rotation  

NASA Technical Reports Server (NTRS)

The spectra of polar motion excitation functions exhibit enhanced power in the fortnightly tidal band. This enhanced power is attributed to ocean tidal excitation. Ocean tide models predict polar motion excitation effects that differ with each other, and with observations, by factors as large as 2-3. There is a need for inproved models for the effect of long-period ocean tides on Earth's rotation.

Gross, Richard S.; Chao, Ben F.; Desai, Shailen D.

1996-01-01

366

Exploring the Lunar Interior with Tides, Gravity and Orientation  

Microsoft Academic Search

Exploration of the internal structure and properties of the Moon continues. Existing information from gravity field, tides and 3-dimensional orientation includes moments of inertia, mean density, tidal Love numbers, tidal dissipation, and fluid-core\\/solid-mantle interactions from dissipation and oblateness. Tracking orbiting spacecraft gives gravity field and a Love number k2. Lunar laser ranging (LLR) determined tides and orientation give Love numbers

James G. Williams; D. H. Boggs; H. Noda

2010-01-01

367

Ocean tide loading effects on new gravity tide measurements made at south of Spain  

NASA Astrophysics Data System (ADS)

Tidal gravity observations have been made recently in Algodonales (ALG) site located in the region of Andalucía, at the south of Spain. Other former gravity tide observations around this region were made in Granada and San Fernando (Vieira et al., 1983), which are 165 km northeast and 85 km southwest distant from ALG, respectively. It is planned to make shortly new gravity measurements in Melilla, which is a Spanish city placed at the other side of the Strait of Gibraltar (north of Morocco). In this way, we will dispose of an interesting gravity profile for studying the elastic response of the Earth at tidal periods in this important area of geodynamic activity. In fact, this broad region is situated around the interaction area of the Eurasia and Africa plates, where various geological structures are present, as the Alboran Sea basin, the Betico-Rifean chain, the Gulf of Cádiz and the Atlas mountain range. Also, the area is affected by occurrence of moderate magnitude earthquakes, mostly focused at shallow and intermediate depths (< 40 km) although exist records of very deep earthquakes located at the south of Granada. The two tectonic plates that interact have different movements slightly, which originates an accumulation of efforts in the fault line, that contributes to the earthquake occurrence in the zone (see e.g. Stich et al., 2006; Buforn et al., 2004; Fullea et al., 2006). The gravity observations made in ALG site, which is situated about 55km far from the coast, are considerably affected by ocean tide loading produced by the effect of the nearest Atlantic Ocean and Mediterranean Sea. Thus, the gravity effect induced by the ocean masses contributes up to 9% of the observed signal, for the main tidal constituents. The ocean loading effects have been calculated following the Farrell's (1972) procedure through the convolution between gravity Green's functions and the ocean tide distribution given by global oceanic models (TPXO7.1, FES2004, GOT00, GOT4.7,..). To improve the loading predictions in the area, we have used the recently developed regional oceanic model named IBER01 (Benavent et al., 2009). The model was constructed by assimilating satellite altimeter data and tide gauge measurements into a hydrodynamic model and is extended through the domain given by 48° .0N to 34° .0N and 6° .0E to 16° .0W, having a resolution of 5'×5'. Thus, the contribution of IBER01 to the tidal loading calculated at ALG site represents about 72% and 55% of the total load for semidiurnal and diurnal waves, respectively. Results obtained show that precise calculations of ocean tide loading improves the interpretation of the gravity tide models obtained in the area and also allow us to assess the efficiency of the global oceanic models around the Strait of Gibraltar where the Mediterranean and Atlantic waters converge.

Arnoso, Jose; Benavent, Maite; Montesinos, Fuensanta G.

2010-05-01

368

Reconstruction of regional mean sea level anomalies from tide gauges using the neural network approach  

NASA Astrophysics Data System (ADS)

Regional mean sea level anomalies (SLA) are estimated from tide gauge values directly using the neural network approach. A neural network is an artificial neural system, a computational model inspired by the notion of neurophysical processes. It consists of several processing elements called neurons, which are interconnected with each other exchanging information. In this presentation a backpropagation network (BPN) is used. In this type of network the neurons are ordered into layers: an input layer on the top, one or more hidden layers below and an output layer at the bottom. The connection strength between the neurons are estimated in a training phase, i.e. the BNP learns from given examples. For our purpose 56 tide gauges are selected from the PSMSL data set that comply with the following conditions: 1) there are more than 11 annual mean values given in [1993,2005] 2) more than 50 annual mean values are given in [1900,2007] and 3) the tide gauge is neighboured by at least one ocean point on a 1x1 degree grid. The selected tide gauges are GIA corrected using the Peltier ICE5G_VM4_L90 dataset available on the PSMSL web site. For each ocean region (trop. Indian, ... South Atlantic to Global Ocean) a separate BPN is trained that uses all tide gauges to compute the regional mean SLA's. To avoid possible problems with the local reference frame all computations are done in the space of temporal derivatives. Beyond that, this makes the data more suitable for the BPN because it better limits the possible range of the numerical values. Furthermore, known regional mean target values are needed to train the BPN. These are derived from gridded satellite altimetry data either processed by GFZ Potsdam (TOPEX/Poseidon data only) and/or the dataset available on the CSIRO sea level web side (combined TOPEX and Jason data). Although every tide gauge has more then 50 years of data, many values are missing, especially prior to 1950. To fill these data gaps at the input layer of the BPN several alternatives are tested. This includes a reconstruction using an EOF basis estimated from all timesteps that have a complete tide gauge dataset. Furthermore a "forecast" network is build, that is trained to compute the values at all tide gauge positions for timestep (n+1) from all values at the steps (n) and (n-1). Additionally an equivalent "backcast" network is constructed that computes the values for step (n-1) from the steps (n) and (n+1). The resulting SLA's are presented. The results appear to be relatively insensitive against what is filled into the data gaps as far as the amount of missing input data does not exceed 20%, i.e. after 1950. Nearly all regions show a sea level rise with a multidecadal/interannual variability superimposed.

Wenzel, M.; Schroeter, J.

2009-04-01

369

Pilot Weather Advisor System  

NASA Technical Reports Server (NTRS)

The Pilot Weather Advisor (PWA) system is an automated satellite radio-broadcasting system that provides nearly real-time weather data to pilots of aircraft in flight anywhere in the continental United States. The system was designed to enhance safety in two distinct ways: First, the automated receipt of information would relieve the pilot of the time-consuming and distracting task of obtaining weather information via voice communication with ground stations. Second, the presentation of the information would be centered around a map format, thereby making the spatial and temporal relationships in the surrounding weather situation much easier to understand

Lindamood, Glenn; Martzaklis, Konstantinos Gus; Hoffler, Keith; Hill, Damon; Mehrotra, Sudhir C.; White, E. Richard; Fisher, Bruce D.; Crabill, Norman L.; Tucholski, Allen D.

2006-01-01

370

Weather assessment and forecasting  

NASA Technical Reports Server (NTRS)

Data management program activities centered around the analyses of selected far-term Office of Applications (OA) objectives, with the intent of determining if significant data-related problems would be encountered and if so what alternative solutions would be possible. Three far-term (1985 and beyond) OA objectives selected for analyses as having potential significant data problems were large-scale weather forecasting, local weather and severe storms forecasting, and global marine weather forecasting. An overview of general weather forecasting activities and their implications upon the ground based data system is provided. Selected topics were specifically oriented to the use of satellites.

1977-01-01

371

Winter Storm (weather)  

NSDL National Science Digital Library

This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. First think about these questions: 1. What is your favorite aspect of winter weather? 2. How does the weather effect your everyday life? Form groups of THREE. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper... 1. In general, when are winds formed? 2. When winds are blowing, how can you ...

Miller, Aubree

2009-09-28

372

Washington Post Weather  

NSDL National Science Digital Library

The Washington Post makes a bid for the already crowded Internet weather market with WeatherPost. Coverage includes current conditions and four-day forecasts for 3,600 cities worldwide, as well as snapshot and time-lapse satellite maps (provided by Accu Weather). For US cities, users may also access UV and air quality maps and data, as well as seasonal maps (snow cover, tanning index, heat index, and BeachCast) and other radar images such as precipitation. Users may enter a city name into the homepage search box, or may browse by country or state/province. The historical weather database offers compiled monthly average weather data for nearly 1,000 cities worldwide; the database is searchable. An aspect of the site that sets it apart from many other weather pages is the weather reference desk, which includes a weather glossary, weather calculators (JavaScript converters for temperature, wind chill, heat index, etc.) and a page devoted to storm chasers.

1997-01-01

373

Space Weather: Welcome, SEC  

NSDL National Science Digital Library

This video presentation welcomes the Space Weather Prediction Center, formerly known as the Space Environment Center or SEC to the National Weather Service (NWS) as an operational entity of the National Centers for Environmental Prediction (NCEP) family. Describing the ways in which space weather affects global communications and power resources, it demonstrates the importance of space weather forecasting as a part of the NWS family of services. With the inclusion of SWPC, the NWS now provides environmental understanding from the sun to the sea.

Comet

2005-01-11

374

Dynamic ocean-tide effects on Earth's rotation  

NASA Technical Reports Server (NTRS)

This article develops 'broad-band' Liouville equations which are capable of determining the effects on the rotation of the Earth of a periodic excitation even at frequencies as high as semi-diurnal; these equations are then used to predict the rotational effects of altimetric, numerical and 32-constituent spherical harmonic ocean-tide models. The rotational model includes a frequency-dependent decoupled core, the effects of which are especially marked near retrograde diurnal frequencies; and a fully dynamic oceanic response, whose effects appear to be minor despite significant frequency dependence. The model also includes solid-earth effects which are frequency dependent as the result of both anelasticity at long periods and the fluid-core resonance at nearly diurnal periods. The effects of both tidal inertia and relative angular momentum on Earth rotation (polar motion, length of day, 'nutation' and Universal Time) are presented for 32 long- and short-period ocean tides determined as solutions to the author's spherical harmonic tide theory. The lengthening of the Chandler wobble period by the pole tide is also re-computed using the author's full theory. Additionally, using the spherical harmonic theory, tidal currents and their effects on rotation are determined for available numerical and altimetric tide height models. For all models, we find that the effects of tidal currents are at least as important as those of tide height for diurnal and semi-diurnal constituents.

Dickman, S. R.

1993-01-01

375

DYNAMICAL TIDES IN ROTATING PLANETS AND STARS  

SciTech Connect

Tidal dissipation may be important for the internal evolution as well as the orbits of short-period massive planets-hot Jupiters. We revisit a mechanism proposed by Ogilvie and Lin for tidal forcing of inertial waves, which are short-wavelength, low-frequency disturbances restored primarily by Coriolis rather than buoyancy forces. This mechanism is of particular interest for hot Jupiters, because it relies upon a rocky core, and because these bodies are otherwise largely convective. Compared to waves excited at the base of the stratified, externally heated atmosphere, waves excited at the core are more likely to deposit heat in the convective region and thereby affect the planetary radius. However, Ogilvie and Lin's results were numerical, and the manner of the wave excitation was not clear. Using WKB methods, we demonstrate the production of short waves by scattering of the equilibrium tide off the core at critical latitudes. The tidal dissipation rate associated with these waves scales as the fifth power of the core radius, and the implied tidal Q is of order ten million for nominal values of the planet's mass, radius, orbital period, and core size. We comment upon an alternative proposal by Wu for exciting inertial waves in an unstratified fluid body by means of compressibility rather than a core. We also find that even a core of rock is unlikely to be rigid. But Ogilvie and Lin's mechanism should still operate if the core is substantially denser than its immediate surroundings.

Goodman, J.; Lackner, C. [Princeton University Observatory, Princeton, NJ 08544 (United States)], E-mail: jeremy@astro.princeton.edu

2009-05-10

376

Statistical Sampling of Tide Heights Study  

NASA Technical Reports Server (NTRS)

The goal of the study was to determine if it was possible to reduce the cost of verifying computational models of tidal waves and currents. Statistical techniques were used to determine the least number of samples required, in a given situation, to remain statistically significant, and thereby reduce overall project costs. Commercial, academic, and Federal agencies could benefit by applying these techniques, without the need to 'touch' every item in the population. For example, the requirement of this project was to measure the heights and times of high and low tides at 8,000 locations for verification of computational models of tidal waves and currents. The application of the statistical techniques began with observations to determine the correctness of submitted measurement data, followed by some assumptions based on the observations. Among the assumptions were that the data were representative of data-collection techniques used at the measurement locations, that time measurements could be ignored (that is, height measurements alone would suffice), and that the height measurements were from a statistically normal distribution. Sample means and standard deviations were determined for all locations. Interval limits were determined for confidence levels of 95, 98, and 99 percent. It was found that the numbers of measurement locations needed to attain these confidence levels were 55, 78, and 96, respectively.

2002-01-01

377

Dynamical Tides in Rotating Planets and Stars  

E-print Network

Tidal dissipation may be important for the internal evolution as well as the orbits of short-period massive planets--hot Jupiters. We revisit a mechanism proposed by Ogilvie and Lin for tidal forcing of inertial waves, which are short-wavelength, low-frequency disturbances restored primarily by Coriolis rather than buoyancy forces. This mechanism is of particular interest for hot Jupiters because it relies upon a rocky core, and because these bodies are otherwise largely convective. Compared to waves excited at the base of the stratified, externally heated atmosphere, waves excited at the core are more likely to deposit heat in the convective region and thereby affect the planetary radius. However, Ogilvie and Lin's results were numerical, and the manner of the wave excitation was not clear. Using WKB methods, we demonstrate the production of short waves by scattering of the equilibrium tide off the core at critical latitudes. The tidal dissipation rate associated with these waves scales as the fifth power of...

Goodman, Jeremy

2008-01-01

378

Probing the tides in interacting galaxy pairs  

NASA Technical Reports Server (NTRS)

Detailed spectroscopic and imaging observations of colliding elliptical galaxies revealed unmistakable diagnostic signatures of the tidal interactions. It is possible to compare both the distorted luminosity distributions and the disturbed internal rotation profiles with numerical simulations in order to model the strength of the tidal gravitational field acting within a given pair of galaxies. Using the best-fit numerical model, one can then measure directly the mass of a specific interacting binary system. This technique applies to individual pairs and therefore complements the classical methods of measuring the masses of galaxy pairs in well-defined statistical samples. The 'personalized' modeling of galaxy pairs also permits the derivation of each binary's orbit, spatial orientation, and interaction timescale. Similarly, one can probe the tides in less-detailed observations of disturbed galaxies in order to estimate some of the physical parameters for larger samples of interacting galaxy pairs. These parameters are useful inputs to the more universal problems of (1) the galaxy merger rate, (2) the strength and duration of the driving forces behind tidally stimulated phenomena (e.g., starbursts and maybe quasi steller objects), and (3) the identification of long-lived signatures of interaction/merger events.

Borne, Kirk D.

1990-01-01

379

Meteorology:Meteorology: Weather and ClimateWeather and Climate  

E-print Network

1 Meteorology:Meteorology: Weather and ClimateWeather and Climate Large Scale Weather SystemsLarge--scale Weather Systemsscale Weather Systems Tropical cyclones (1-2) Location, Structure, Life-cycle Formation and modification, airmasses that effect the British Isles Airmasses affecting the British Isles

380

Weather and emotional state  

NASA Astrophysics Data System (ADS)

Introduction Given the proven effects of weather on the human organism, an attempt to examine its effects on a psychic and emotional level has been made. Emotions affect the bio-tonus, working ability and concentration, hence their significance in various domains of economic life, such as health care, education, transportation, tourism, etc. Data and methods The research has been made in Sofia City within a period of 8 months, using 5 psychological methods (Eysenck Personality Questionnaire (EPQ), State-Trait Anxiety Inventory (STAI), Test for Self-assessment of the emotional state (developed by Wessman and Ricks), Test for evaluation of moods and Test "Self-confidence - Activity - Mood" (developed by the specialists from the Military Academy in Saint Petersburg). The Fiodorov-Chubukov's complex-climatic method was used to characterize meteorological conditions because of the purpose to include in the analysis a maximal number of meteorological elements. 16 weather types are defined in dependence of the meteorological elements values according to this method. Abrupt weather changes from one day to another, defined by the same method, were considered as well. Results and discussions The results obtained by t-test show that the different categories of weather lead to changes in the emotional status, which indicates a character either positive or negative for the organism. The abrupt weather changes, according to expectations, have negative effect on human emotions but only when a transition to the cloudy weather or weather type, classified as "unfavourable" has been realized. The relationship between weather and human emotions is rather complicated since it depends on individual characteristics of people. One of these individual psychological characteristics, marked by the dimension "neuroticism", has a strong effect on emotional reactions in different weather conditions. Emotionally stable individuals are more "protected" to the weather influence on their emotions, while those who are emotionally unstable have a stronger dependence to the impacts of the weather.

Spasova, Z.

2010-09-01

381

On tidal resonance in the global ocean and the back?effect of coastal tides upon open?ocean tides  

Microsoft Academic Search

The resonance of semi?diurnal tidal elevations is investigated with a forward numerical forced damped global tide model and an analytical model of forced?damped tides in a deep ocean basin coupled to a shelf. The analytical model contains the classical half?wavelength and quarter?wavelength resonances in the deep ocean and shelf, respectively, as well as a forcing?scale dependence which depends on the

Brian K. Arbic; Richard H. Karsten; Chris Garrett

2009-01-01

382

Space weather applications with PICARD  

NASA Astrophysics Data System (ADS)

The PICARD mission aims at providing a better understanding of the origin of solar variability and the relations between the Sun and Earth's climate. Some of the instruments from PICARD will also be of direct interest to space weather. SODISM will provide regular UV images at 215 and 393 nm wavelength and PREMOS will measure the solar spectral irradiance in 5 channels, 3 of which are in the visible and in the near-infrared. Some potential applications will be discussed as well as synergies with other spectral irradiance observations, such as by LYRA on PROBA2 and EVE on SDO.

Dudok de Wit, Thierry; Thuillier, Gerard

383

Designing a Weather Station  

ERIC Educational Resources Information Center

The collection and analysis of weather data is crucial to the location of alternate energy systems like solar and wind. This article presents a design challenge that gives students a chance to design a weather station to collect data in advance of a large wind turbine installation. Data analysis is a crucial part of any science or engineering…

Roman, Harry T.

2012-01-01

384

Mild and Wild Weather.  

ERIC Educational Resources Information Center

Presents background information and six activities that focus on clouds, precipitation, and stormy weather. Each activity includes an objective, recommended age level(s), subject area(s), and instructional strategies. Also provided are two ready-to-copy pages (a coloring page on lightning and a list of weather riddles to solve). (JN)

NatureScope, 1985

1985-01-01

385

People and Weather.  

ERIC Educational Resources Information Center

Provides: (1) background information on ways weather influences human lives; (2) activities related to this topic; and (3) a ready-to-copy page with weather trivia. Each activity includes an objective, list of materials needed, recommended age level(s), subject area(s), and instructional strategies. (JN)

NatureScope, 1985

1985-01-01

386

Weather Cardboard Carpentry  

ERIC Educational Resources Information Center

Included are instructions and diagrams for building weather instruments (wind vane, Celsius temperature scale, and anemometer) from simple tools and Tri-Wall, a triple-thick corrugated cardboard. Ordering sources for Tri-Wall are listed. Additional weather instruments that can be constructed are suggested. (CS)

DeBruin, Jerome E.

1977-01-01

387

Home Weatherization Visit  

SciTech Connect

Secretary Steven Chu visits a home that is in the process of being weatherized in Columbus, OH, along with Ohio Governor Ted Strickland and Columbus Mayor Michael Coleman. They discuss the benefits of weatherization and how funding from the recovery act is having a direct impact in communities across America.

Chu, Steven

2009-01-01

388

Weathering warming in Colorado  

SciTech Connect

This article describes the results of a field experiment heating patches of a subalpine meadow in the Rocky Mountains to determine what will weather and what will weather under projected global warming. The problems with actually measuring the feedback is discussed, along with the changes which come as the meadow is heated.

Gillis, A.M.

1996-03-01

389

Teacher's Weather Sourcebook.  

ERIC Educational Resources Information Center

This book is a teaching resource for the study of weather-related phenomena. A "weather unit" is often incorporated into school study because of its importance to our daily lives and because of its potential to cut across disciplinary content. This book consists of two parts. Part I covers the major topics of atmospheric science such as the modern…

Konvicka, Tom

390

Erosion and Weathering  

NSDL National Science Digital Library

Weathering and erosion work together as natural forces, removing and transporting material. Sediments, the by-products of these processes, are subsequently deposited to produce characteristic landforms such as dunes, deltas, and glacial moraines. This slide show presents images of landforms that result from erosion and weathering, as well as measures designed to mitigate their unwanted effects.

391

Critical Fire Weather Patterns  

E-print Network

-- 1.1 Typical Summer Weather Cycle PDT -- 1.1 Dry Thunderstorms PHX -- 1.1 North Winds PHX -- 2 Thunderstorms RNO -- 1.1 Washoe Zephyr RNO -- 2.1 Winds & Thunderstorms SAC -- 1.1 Pre--Frontal Winds SLC -- 1 days. Normally the pacific weather front will have enough instability for a few dry thunderstorms

Clements, Craig

392

What Is Space Weather?  

NSDL National Science Digital Library

This resource provides a brief overview of the phenomenon known as space weather, which happens when energetic particles emitted by the Sun impact the Earth's magnetosphere. Users can view images, video clips, and animations of auroras and other types of space weather. A set of links to related websites is also provided.

393

Benign Weather Modification.  

National Technical Information Service (NTIS)

Weather modification is a technology once embraced by the U.S. military as a tool to help both wartime and peacetime missions. However, interest in the ability to modify weather has waned over recent years and is now nearly non-existent. This study examin...

B. E. Coble

1996-01-01

394

Benign Weather Modification.  

National Technical Information Service (NTIS)

Weather modification is a technology once embraced by the United States (US) military as a tool to help both wartime and peacetime missions. However, interest in the ability to modify weather has waned over recent years and is now nearly nonexistent. This...

B. B. Coble

1997-01-01

395

Weathering Database Technology  

ERIC Educational Resources Information Center

Collecting weather data is a traditional part of a meteorology unit at the middle level. However, making connections between the data and weather conditions can be a challenge. One way to make these connections clearer is to enter the data into a database. This allows students to quickly compare different fields of data and recognize which…

Snyder, Robert

2005-01-01

396

Exercising in Cold Weather  

MedlinePLUS

... www.nia.nih.gov/Go4Life Exercising in Cold Weather Exercise has benefits all year, even during winter. ... activities when it’s cold outside: l Check the weather forecast. If it’s very windy or cold, exercise ...

397

Fabulous Weather Day  

ERIC Educational Resources Information Center

Each year, first graders at Kensington Parkwood Elementary School in Kensington, Maryland, look forward to Fabulous Weather Day. Students learn how meteorologists collect data about the weather, how they study wind, temperature, precipitation, basic types/characteristics of clouds, and how they forecast. The project helps the students grow in…

Marshall, Candice; Mogil, H. Michael

2007-01-01

398

On Observing the Weather  

ERIC Educational Resources Information Center

Rain, sun, snow, sleet, wind... the weather affects everyone in some way every day, and observing weather is a terrific activity to attune children to the natural world. It is also a great way for children to practice skills in gathering and recording information and to learn how to use simple tools in a standardized fashion. What better way to…

Crane, Peter

2004-01-01

399

Weathering and weathering rates of natural stone  

NASA Astrophysics Data System (ADS)

Physical and chemical weathering were studied as separate processes in the past. Recent research, however, shows that most processes are physicochemical in nature. The rates at which calcite and silica weather by dissolution are dependent on the regional and local climatic environment. The weathering of silicate rocks leaves discolored margins and rinds, a function of the rocks' permeability and of the climatic parameters. Salt action, the greatest disruptive factor, is complex and not yet fully understood in all its phases, but some of the causes of disruption are crystallization pressure, hydration pressure, and hygroscopic attraction of excess moisture. The decay of marble is complex, an interaction between disolution, crack-corrosion, and expansion-contraction cycies triggered by the release of residual stresses. Thin spalls of granites commonly found near the street level of buildings are generally caused by a combination of stress relief and salt action. To study and determine weathering rates of a variety of commercial stones, the National Bureau of Standards erected a Stone Exposure Test Wall in 1948. Of the many types of stone represented, only a few fossiliferous limestones permit a valid measurement of surface reduction in a polluted urban environment.

Winkler, Erhard M.

1987-06-01

400

Scholastic: Weather Watch  

NSDL National Science Digital Library

The Weather Watch series of online projects investigates seasonal weather phenomena. Students discover the scientific explanations for these events, and use tools and resources for enhanced research. The Hurricanes project allows students to monitor patterns and plot the progression of hurricanes. The Winter Storms project contains an interactive weather maker allowing students to create different weather patterns by changing factors. A winter storm timeline provides stories of the harshest blizzards that have occurred in the U.S. The Weather Reporters project includes a selection of hands-on science experiments for classroom participation, leading up to sharing results online with students worldwide. Each project provides assessment tools and lesson plan suggestions for educators. Links are provided for additional resources.

401

Predicting the Weather  

NSDL National Science Digital Library

This Topic in Depth explores the science behind predicting the weather. First, the United States Search and Rescue Task Force describe the basic tools and knowledge used to create weather forecasts (1). Students can find concise, clear explanations of weather, fronts and air masses, high and low pressure, precipitation, and water vapor and humidity as well. By performing the activities presented in the second website, fourth grade students can learn about weather instruments and data collection (2). This website, produced by the Government of Saskatchewan, also explores how the weather can impact local communities. Third, Edheads offers a Macromedia Flash Player enhanced interactive module allowing students to predict the weather by examining weather maps (3 ). Through this website, users can become familiar with the concepts of warm and cold fronts, wind direction and speed, air pressure, and humidity. The fourth website, supplied by Annenberg / CPB, discusses weather satellites, Doppler radar, and additional tools forecasters use to predict the weather (4). Students can find a wind chill calculator along with a brief discussion of the history of forecasting and weather lore. Next, NOAA provides graphics for five forecast models: the ETA, the Global Forecast System (GFS), the Wave Watch III (WW3), the Nested Grid model (NGM), and the Rapid Update Cycle (RUC) (5). Outputs are available for North America, North Pacific, Western North Atlantic, and the Polar Ice Drift. Users can find links to detailed descriptions of the inputs and history of each model. Sixth, the British government's Met Office describes numerical modeling and its components (6). Students and educators can learn about the future in forecasting as well as educational opportunities with the Cooperative Program for Meteorology, Education, and Training (COMET).

402

Improved Estimates of Temporally Coherent Internal Tides and Energy Fluxes from Satellite Altimetry  

NASA Technical Reports Server (NTRS)

Satellite altimetry has opened a surprising new avenue to observing internal tides in the open ocean. The tidal surface signatures are very small, a few cm at most, but in many areas they are robust, owing to averaging over many years. By employing a simplified two dimensional wave fitting to the surface elevations in combination with climatological hydrography to define the relation between the surface height and the current and pressure at depth, we may obtain rough estimates of internal tide energy fluxes. Initial results near Hawaii with Topex/Poseidon (T/P) data show good agreement with detailed 3D (three dimensional) numerical models, but the altimeter picture is somewhat blurred owing to the widely spaced T/P tracks. The resolution may be enhanced somewhat by using data from the ERS-1 (ESA (European Space Agency) Remote Sensing) and ERS-2 satellite altimeters. The ERS satellite tracks are much more closely spaced (0.72 deg longitude vs. 2.83 deg for T/P), but the tidal estimates are less accurate than those for T/P. All altimeter estimates are also severely affected by noise in regions of high mesoscale variability, and we have obtained some success in reducing this contamination by employing a prior correction for mesoscale variability based on ten day detailed sea surface height maps developed by Le Traon and colleagues. These improvements allow us to more clearly define the internal tide surface field and the corresponding energy fluxes. Results from throughout the global ocean will be presented.

Ray, Richard D.; Chao, Benjamin F. (Technical Monitor)

2002-01-01

403

Mapping Hurricane Inland-Storm Tides  

NASA Astrophysics Data System (ADS)

Historically, hurricane-induced storm-tides were documented through analysis of structural or vegetative damage and high-water marks. However, these sources rarely provided quantitative information about the timing of the flooding, the sequencing of multiple paths by which the storm-surge waters arrived, or the magnitude of waves and wave run-up comprising floodwaters. In response to these deficiencies, the U.S. Geological Survey (USGS) developed and deployed an experimental mobile storm-surge network to provide detailed time-series data for selected hurricane landfalls. The USGS first deployed the network in September 2005 as Hurricane Rita approached the Texas and Louisiana coasts. The network for Rita consisted of 32 water-level and 14 barometric-pressure monitoring sites. Sensors were located at distances ranging from a few hundred feet to approximately 30 miles inland and sampled 4,000 square miles. Deployments have also occurred for Hurricanes Wilma, Gustav, and Ike. For Hurricane Gustav, more than 100 water level sensors were deployed. Analysis of the water-level data enable construction of maps depicting surge topography through time and space, essentially rendering elements of a 3-dimensional view of the storm-surge dome as it moves on- shore, as well as a map of maximum water-level elevations. The USGS also acquired LIDAR topographic data from coasts impacted by hurricanes. These data reveal extreme changes to the beaches and barrier islands that arise from hurricane storm surge and waves. By better understanding where extreme changes occur along our coasts, we will be able to position coastal structures away from hazards.

Turco, M.; East, J. W.; Dorsey, M. E.; McGee, B. D.; McCallum, B. E.; Pearman, J. L.; Sallenger, A. H.; Holmes, R. R.; Berembrock, C. E.; Turnipseed, D. P.; Mason, R. R.

2008-12-01

404

The Anelastic Equilibrium Tide in Giant Planets  

NASA Astrophysics Data System (ADS)

Once a planetary system is formed, its dynamical evolution is governed by gravitational interactions between its components, be it a star-planet or planet-satellite interaction. By converting kinetic energy into heat, the tides pertub their orbital and rotational properties. The rate at which the system evolves depends on the physical properties of tidal dissipation. Therefore, to understand the past history and predict the fate of a binary system, one has to identify the dissipative processes that achieve this conversion of energy. Planetary systems display a large diversity of planets by their composition. Since tidal mechanism is closely related with the internal structure of the perturbed body, one has to investigate its effects on either its fluid and solid layers. Studies have been carried out on tidal effects in fluid bodies such as stars and envelopes of giant planets. However, the planetary solid regions may also contribute to tidal dissipation, be it the mantles of Earth-like planets that have been investigated by many works, or the cores of giant planets. The purpose of our study is to determine the tidal dissipation in the solid central regions of giant planets, taking into account the presence of a fluid envelope. We derive the different Love numbers that describe the anelastic deformation and discuss the dependence of the quality factor Q on the rheological parameters and the size of the core. Taking plausible values for these parameters, and discussing the frequency-dependence of the solid dissipation, we show how this mechanism may compete with the dissipation in fluid layers, when applied to Jupiter- and Saturn-like planets. We also discuss the case of the icy giants Uranus and Neptune. Finally, we present the way to implement the results in the equations that describe the dynamical evolution of planetary systems.

Remus, Francoise; Mathis, S.; Zahn, J.; Lainey, V.

2012-10-01

405

Global and regional past sea level from an ensemble of reconstructions based on Altimetry, OGCM runs and tide gauges  

NASA Astrophysics Data System (ADS)

For the past decades, information about sea level is sparse and essentially based on tide gauge records along islands and continental coastlines. This dataset cannot alone inform on open ocean regional variability. But it is important to know the dominant modes of the global and regional sea level variability on interannual/decadal/multidecadal time scales in order to understand the physical processes which drive them. For this purpose, several two-dimensional (2-D) past sea level reconstructions over the last century have been developed (e.g., Chambers et al., 2002a, b, Church et al., 2004, Berge-Nguyen et al., 2008, Llovel et al., 2009, Church and White, 2011, Calafat et al. 2010, Meyssignac et al., 2011, 2012, Ray and Douglas, 2011, Hamlington et al., 2011). In this presentation we use the Empirical Orthogonal Function -EOF- approach to reconstruct past sea level. This approach uses EOFs to combine long tide gauge records of limited spatial coverage and 2-D sea level patterns based on the altimetry dataset or on runs from Ocean General Circulation Models (OGCM). We developed 5 past sea level reconstructions based on EOFs from OGCMs with data assimilation, 2 reconstructions based on EOFs from OGCMs without data assimilation and 1 reconstruction based EOFs from satellite altimetry. Compared to previous reconstructions in the literature these reconstructions use data corrected for glacial isostatic adjustment (both tide gauge records and Altimetry) and tide gauge records corrected for vertical crustal motion with GPS measurements when available. The 8 reconstructions are based on more than 400 tide gauge records and cover the period 1900-2012 on a monthly basis. Performances of the 8 reconstructions are discussed in comparison with independent tide gauges not used in the reconstruction process. We also discuss the differences between the different reconstructions in terms of global mean sea level over the period 1900-2012 and in terms of sea level trend patterns over the period 1950-2012. Then, we present a ';mean' reconstruction based on the ensemble average of the 8 individual reconstructions. The dominant modes of temporal variability and the spatial trend patterns of this mean reconstruction are discussed.

Meyssignac, B.; Palanisamy, H. K.; Cazenave, A. A.; Shum, C.

2013-12-01

406

A weather generator for hydrological, ecological, and agricultural applications  

Microsoft Academic Search

This paper presents a weather generator that allows simulation of hydrometeorological variables representative of a given geographic location: precipitation, total cloud cover, incoming shortwave radiation, air temperature, humidity, and wind speed. The approach captures the essential relationships among the quantities of interest, while modeling the diurnal variation of weather conditions at the hourly scale. Precipitation is considered to be the

Valeriy Y. Ivanov; Rafael L. Bras; David C. Curtis

2007-01-01

407

ORIGINAL PAPER Interannual variations in fire weather, fire extent,  

E-print Network

-Euroamerican tree-ring-based fire records. We investigated how interannual variability in two fire weather indicesORIGINAL PAPER Interannual variations in fire weather, fire extent, and synoptic-scale circulation by wet winters and dry summers, and by high fire activity. The importance of synoptic-scale circulation

Taylor, Alan

408

Environmental Education Tips: Weather Activities.  

ERIC Educational Resources Information Center

Provides weather activities including questions, on weather, heating the earth's surface, air, tools of the meteorologist, clouds, humidity, wind, and evaporation. Shows an example of a weather chart activity. (RT)

Brainard, Audrey H.

1989-01-01

409

Weather and Fire  

E-print Network

Recent cooler temperatures and rain showers have moderated fire behavior across Alaska. “The fires are taking a breather, but our firefighters are not, ” said Pete Buist, Fire Information Officer. When the weather provides a break like this, firefighters take advantage of it by redoubling their efforts and maximizing progress towards completing fire management objectives. Yesterday’s weather included over 3,000 lightning strikes across the state and scattered showers from inch to nearly an inch in some locations. Mild temperatures and scattered showers are expected to continue into the weekend. A thermal Weather is one of the most significant factors in determining the severity of wildland fires. The intensity of fires and the rate with which they spread is directly related to the wind speed, temperature and relative humidity. Accurate and timely weather information is vital to the planning and execution of strategies for suppressing wildfires. trough is moving northward across Alaska, but thunderstorms will decrease and temperatures will increase over the next few days. A high pressure ridge is attempting to move westward into the Interior, and if successful, warm weather could return next week. For additional details on fire weather see the AICC weather page at

unknown authors

2010-01-01

410

Fire Weather Forecasting: Clear Communications  

NSDL National Science Digital Library

The âFire Weather Forecasting: Clear Communicationsâ distance learning module offers best practices for Fire Weather Forecasters needing to communicate weather information when deployed in the field. The 30-minute module defines strategies for communicating with Weather Forecast Offices and with customers. Examples include writing a useful fire weather forecast discussion and undertaking proper planning to quickly and accurately disseminate information. This distance learning module is part of the Advanced Fire Weather Forecasters Course.

Comet

2008-03-05

411

Lunar and Solar Torques on the Oceanic Tides  

NASA Technical Reports Server (NTRS)

Brosche and Seiler recently suggested that direct lunar and solar tidal torques on the oceanic tides play a significant role in the earth's short-period angular momentum balance ("short-period" here meaning daily and sub-daily). We reexamine that suggestion here, concentrating on axial torques and hence on variations in rotation rate. Only those spherical harmonic components of the ocean tide having the same degree and order as the tidal potential induce nonzero torques. Prograde components (those moving in the same direction as the tide-generating body) produce the familiar secular braking of the earth's rotation. Retrograde components, however, produce rapid variations in UTI at twice the tidal frequency. There also exist interaction torques between tidal constituents, e.g. solar torques on lunar tides. They generate UTI variations at frequencies equal to the sums and differences of the original tidal frequencies. We give estimates of the torques and angular momentum variations for each of the important regimes, secular to quarter-diurnal. For the M(sub 2) potential acting on the M(sub 2) ocean tide, we find an associated angular momentum variation of amplitude 3 x 10(exp 19) N m. This is 5 to 6 orders of magnitude smaller than the angular momentum variations associated with tidal currents. We conclude that these torques do not play a significant role in the short-period angular momentum balance.

Ray, Richard D.; Bills, Bruce G.; Chao, Benjamin F.

1998-01-01

412

The gravitational effect of ocean tide loading at high latitude coastal stations in Norway  

NASA Astrophysics Data System (ADS)

Gravity measurements close to the ocean are strongly affected by ocean tide loading (OTL). The gravitational OTL effect consists of three parts, i.e. a change in gravity caused by direct attraction from the variable water-masses, by displacement of the observing point due to the load, and by redistribution of masses due to crustal deformation. We compare the OTL gravitational effect of several global models to observed time-series of gravity to identify the best model for four arctic observation sites. We also investigate if the global models are sufficient for correcting gravity observations. The NAO99b model fits the observations best at three stations. At two stations (Tromsø and Bodø) the global models explain the variability in the observations well. At the other two (Honningsvåg and Andøya), a significant periodic signal remains after the OTL correction has been applied. We separate two of the gravitational effects, the direct attraction and the change in gravity due to displacement, to study the local effects. Simple geometric models of the water load and independent measurements from local tide-gauges are used to calculate these effects. This leads to improved correspondence with the OTL signal, hence demonstrating the importance of careful modelling of local effects for correction of gravity observations in coastal stations.

Lysaker, D. I.; Breili, K.; Pettersen, B. R.

2008-09-01

413

World Weather Information Service  

NSDL National Science Digital Library

The World Meteorological Organization Web site offers the World Weather Information Service page. Here, visitors will find official weather forecasts and climatological information for selected cities worldwide. Users choose a particular continent and country, and are then presented with a list of various cities they can get information on. This includes the date and time of the current forecast, minimum and maximum temperatures for that day, a general cloud description, and a monthly review of various data for that city. If for nothing else, the site does a good job of providing a very straightforward and easy way to find weather information from hundreds of cities around the globe.

414

Weather Map Assignment  

NSDL National Science Digital Library

I gave this assignment so that students could relate real-time weather changes to mid-latitude cyclones and air mass movement. Basically, by the time I assigned the project, we have discussed all the necessary weather phenomena and this project gives the students a way to apply what we have discussed to "reality" by explaining why the weather occurred the way it did over a short time period. It also provides me with a way to assess how well they are able to tie all the major concepts together, which is one of the goals of the course.

Brueseke, Matt

415

Weather Observing Fundamentals  

NSDL National Science Digital Library

"Weather Observing Fundamentals" provides guidance for U.S. Navy Aerographer's Mates, Quartermasters, and civilian observers tasked with taking and reporting routine, special, and synoptic observations. Although the focus of this lesson is on shipboard observations, much of the content applies to land-based observing and reporting as well. The lesson details standard procedures for taking accurate weather observations and for encoding those observations on COMNAVMETOCCOM Report 3141/3. Exercises throughout the lesson and four weather identification drills at the end provide learners with opportunities to practice and build their skills. The lesson covers a large amount of content. You may wish to work through the material in multiple sessions.

Comet

2014-03-11

416

Weathering and Erosion  

NSDL National Science Digital Library

This Classroom Connectors lesson plan discusses weather conditions and their contribution to weathering and erosion. Students learn to explain the process of physical and chemical weathering. They also learn to compare and contrast erosion resulting from wind, ice and water. The site provides goals, objectives, an outline, time required, materials, activities, and closure ideas for the lesson. The Classroom Connectors address content with an activity approach while incorporating themes necessary to raise the activity to a higher cognition level. The major motivation is to employ instructional strategies that bring the students physically and mentally into touch with the science they are studying.

417

WeatherTracker  

NSDL National Science Digital Library

WeatherTracker is the ideal desktop application for anyone who always wants to know what the weather outside is like. The temperature, barometric pressure, humidity, winds, and current conditions can be displayed in three different formats, updated hourly for North American Cities. The local forecasts, climate data and near shore marine forecasts can be displayed in other windows and are available for select North American cities. Other cities are limited to temperature and current conditions. WeatherTracker is shareware with a fee of $20.00.

418

Wonderful World of Weather  

NSDL National Science Digital Library

This website uses real time data for many activities for learning about the weather. It can be modified to fit virtually any grade level. The project is broken up into 3 sets of lessons; Introductory Activities, Real Time Data Activities, and Language Arts Activities. Each lesson gives a recommended time for completion, to help keep students and teachers on track. There is a helpful teachers guide section with background information about real time data, curriculum standards, and assessment suggestions. Th students gallery has many examples of real projects other students have already created. There is also a helpful reference guide, with information on real time weather, projects, and weather lesson plans.

2006-01-01

419

Space Weather Now  

NSDL National Science Digital Library

The NOAA Space Weather Now website provides non-technical information and an assortment of images detailing current space weather. Visitors can find summaries describing auroras, plots of current auroral ovals on the poles, and viewing information for the Northern and Southern Hemispheres. The Real-Time Solar Wind Pages furnish dynamic plots of data, geomagnetic activity test product information, and resources about the four instruments used to collect data on geomagnetic storms. The website features Space Weather Scales to help the public understand the severity of environmental disturbances due to geomagnetic storms, solar radiation storms, and radio blackouts. Visitors can find the latest news, alerts, advisory bulletins, and much more.

420

Successfully Transitioning Science Research to Space Weather Applications  

NASA Technical Reports Server (NTRS)

The awareness of potentially significant impacts of space weather on spaceand ground ]based technological systems has generated a strong desire in many sectors of government and industry to effectively transform knowledge and understanding of the variable space environment into useful tools and applications for use by those entities responsible for systems that may be vulnerable to space weather impacts. Essentially, effectively transitioning science knowledge to useful applications relevant to space weather has become important. This talk will present proven methodologies that have been demonstrated to be effective, and how in the current environment those can be applied to space weather transition efforts.

Spann, James

2012-01-01

421

Weathering in a Cup.  

ERIC Educational Resources Information Center

Two easy student activities that demonstrate physical weathering by expansion are described. The first demonstrates ice wedging and the second root wedging. A list of the needed materials, procedure, and observations are included. (KR)

Stadum, Carol J.

1991-01-01

422

Weathering of Martian Evaporites  

NASA Technical Reports Server (NTRS)

Evaporites in martian meteorites contain weathering or alteration features that may provide clues about the martian near-surface environment over time. Additional information is contained in the original extended abstract.

Wentworth, S. J.; Velbel, M. A.; Thomas-Keprta, K. L.; Longazo, T. G.; McKay, D. S.

2001-01-01

423

Tombstone Weathering Lab  

NSDL National Science Digital Library

Students work in groups in a cemetery to collect a quantitative and a qualitative measure of the extent of weathering of tombstones and their ages. The data are shared between all students, graphed as scatter plots, and the rate of weathering is estimated. Students write about and then discuss the results, the difference between the quantitative and qualitative measures, and speculate on factors in addition to time that may be important for weathering rate. The exercise ends with each students writing a hypothesis about a factor that influences weathering rate and describing a research project that could test that hypothesis. This activity is aimed at developing an understanding of the scatter in "real data", allowing for practice of team work, and hypothesis generation and testing. Designed for a geomorphology course Has minimal/no quantitative component

Anders, Alison

424

Weather Information Processing  

NASA Technical Reports Server (NTRS)

Science Communications International (SCI), formerly General Science Corporation, has developed several commercial products based upon experience acquired as a NASA Contractor. Among them are METPRO, a meteorological data acquisition and processing system, which has been widely used, RISKPRO, an environmental assessment system, and MAPPRO, a geographic information system. METPRO software is used to collect weather data from satellites, ground-based observation systems and radio weather broadcasts to generate weather maps, enabling potential disaster areas to receive advance warning. GSC's initial work for NASA Goddard Space Flight Center resulted in METPAK, a weather satellite data analysis system. METPAK led to the commercial METPRO system. The company also provides data to other government agencies, U.S. embassies and foreign countries.

1991-01-01

425

Microbial Weathering of Olivine  

NASA Astrophysics Data System (ADS)

Controlled microbial weathering of olivine experiments displays a unique style of nanoetching caused by biofilm attachment to mineral surfaces. We are investigating whether the morphology of biotic nanoetching can be used as a biosignature.

Longazo, T. G.; Wentworth, S. J.; Southam, G.; McKay, D. S.

2002-03-01

426

Weather and Climate.  

National Technical Information Service (NTIS)

Recommendations for using space observations of weather and climate to aid in solving earth based problems are given. Special attention was given to: (1) extending useful forecasting capability of space systems, (2) reducing social, economic, and human lo...

1975-01-01

427

Winter Weather: Outdoor Safety  

MedlinePLUS

... During a Wildfire Responders Wildfire Smoke After a Fire Worker Safety During Fire Cleanup Wildfires PSAs Related Links Winter Weather Extreme ... a two-wave radio, waterproof matches and paraffin fire starters with you. Do not use alcohol and ...

428

Winter Weather: Hypothermia  

MedlinePLUS

... During a Wildfire Responders Wildfire Smoke After a Fire Worker Safety During Fire Cleanup Wildfires PSAs Related Links Winter Weather Extreme ... at Disaster Sites Preventing Chain Saw Injuries During Tree Removal Electrical Safety and Generators Handling Human Remains ...

429

Winter Weather: Indoor Safety  

MedlinePLUS

... During a Wildfire Responders Wildfire Smoke After a Fire Worker Safety During Fire Cleanup Wildfires PSAs Related Links Winter Weather Extreme ... 3 feet of anything that may catch on fire, such as drapes, furniture, or bedding. Never cover ...

430

Palmer Automatic Weather Station  

NSF Publications Database

... EAM NSF Org: OD / OPP Date : December 06, 1991 File : opp93040 DIVISION OF POLAR PROGRAMS OFFICE OF ... Palmer Automatic Weather Station) To: Files (S.7 - Environment) This Environmental Action Memorandum ...

431

Cold-Weather Sports  

MedlinePLUS

Ahh, winter! Shorter days. Frigid temperatures. Foul weather. What better time to be outdoors? Winter sports can help you burn calories, increase your cardiovascular fitness, and strengthen muscles. Activities that are ...

432

Influence of fortnightly earth tides at Kilauea Volcano, Hawaii  

SciTech Connect

Analysis of 52 historic eruptions confirms the premise that fortnightly earth tides play a significant role in triggering activity at Kilauea Volcano, Hawaii. Since January 1832, nearly twice as many eruptions have occurred nearer fortnightly tidal maximum than tidal minimum (34 vs 18). A straightforward significance test indicates that the likelihood of a fortnightly tidal influence on Kilauea eruptions is roughly 90%. This is not the case for Mauna Loa Volcano, where 37 historic eruptions have been distributed randomly with respect to the fortnightly tide. At Kilauea, stresses induced by fortnightly earth tides presumably act in concert with volcanic and tectonic stresses to trigger shallow magma movements along preexisting zones of weakness. Differences in structure or internal plumbing may limit the effectiveness of this mechanism at Mauna Loa. Tidal effects seem to be less marked at shields than at some island-arc volcanoes, possibly because higher average volcanic stress rates in Hawaii more often override the effects of tidal stresses.

Dzurisin, D.

1980-11-01

433

The Anomalously High Pole Tide in the North and Baltic Seas Estimated by the PSMSL Tide Gauge Data  

NASA Astrophysics Data System (ADS)

Pole tide driven by the Chandler wobble, has the period of about 14 months and typical amplitudes in the World Ocean of ~ 0.5 cm. However, in the North and Baltic Seas they are anomalously high. To examine this effect we used long monthly sea level records from 80 stations with the length up to 212 years. High-resolution spectra revealed a cluster of neighboring peaks with periods from 410 to 440 days. The results of spectral analysis were applied to estimate the integral amplitudes of pole tides from all available tide gauges along the coast of seas. The height of the pole tide was found to gradually increase from the entrance of the Baltic Sea (Danish Straits) to the northeast end of the Baltic Sea. The largest amplitudes - up to 4.5-7 cm - were observed in the heads of the Gulf of Finland and the Gulf of Bothnia. Significant temporal fluctuations in amplitudes and periods of the pole tide were observed during XIX and XX centuries.

Medvedev, Igor; Rabinovich, Alexander; Kulikov, Evgueni

2014-05-01

434

Wonderful World of Weather  

NSDL National Science Digital Library

This standards-based unit has been created for use by students in the elementary grades to investigate weather phenomena both locally as well as in other places around the world. By using hands-on activities and real-time data investigations, students develop a basic understanding of how weather can be described in measurable quantities. The lesson plans have been designed to allow teachers to select the ones which fit into their curriculum, and to allow for flexibility in implementation.

2011-01-01

435

Weathering of Minerals  

NSDL National Science Digital Library

Students determine the % change in mass of mineral samples that have been placed in a rock tumbler. They graph the relationship between the hardness of the mineral and the % change in mass. They then consider why some of the mineral samples do not conform the the relationship they graphed. They investigate the physical properties of the outliers and consider how the physical properties contributed to the rate of weathering, and what kind of weathering occured in the rock tumbler.

Van Norden, Wendy

436

Weather Here and There  

NSDL National Science Digital Library

The Global Education Project of the Resource for Science Education Program offers the Weather Here and There educational unit. The Web site consists of six lessons geared for students in grades four through six that cover everything from characteristics of the Earth's atmosphere to forecasting the weather. Each lesson contains the objectives, materials, background information, vocabulary, evaluation, etc. needed to easily prepare and complete each.

1995-01-01

437

TypoWeather  

NSDL National Science Digital Library

The TypoWeather application is a great way to stay on top of the latest weather conditions. This handy device presents users with a five day outlook and an hourly breakdown that is updated based on data from the National Meteorological Service. Visitors can customize their layout to include alerts about certain meteorological conditions, such as wind patterns, humidity, and more. This version is compatible with all operating systems.

2014-03-13

438

Google Earth Weather Bundle  

NSDL National Science Digital Library

The Google Earth Weather Bundle, from the Department of Atmospheric Sciences at the University of Illinois, gives the user a suite of automatically updating weather products that can be overlaid in any fashion he or she desires. It can be downloaded from the department's web site at the University of Illinois, and is meant for worldwide use by a wide range of audiences, from the general public to meteorologists.

439

Weathering and Erosion  

NSDL National Science Digital Library

In this multi-station lab, learners conduct a series of experiments to explore the processes and effects of weathering and erosion. Using the results from these explorations, learners design and conduct an experiment comparing the rate of erosion in different biomes. Use this activity to teach weathering and erosion, and also to illustrate how scientists often use the results of one experiment to inspire another. This activity is intended to be conducted over multiple meetings.

Whitfield, Lise

2010-01-01

440

Tide-surge interaction in the English Channel  

NASA Astrophysics Data System (ADS)

The English Channel is characterised by strong tidal currents and a wide tidal range, such that their influence on surges is expected to be non-negligible. In order to better assess storm surges in this zone, tide-surge interactions are investigated. A preliminary data analysis on hourly surges indicates some preferential times of occurrence of large storm surges at rising tide, especially in Dunkerque. To examine this further, a numerical modelling approach is chosen, based on the 2DH shallow-water model (MARS). The surges are computed both with and without tide interaction. For the two selected events (the November 2007 North Sea and March 2008 Atlantic storms), it appears that the instantaneous tide-surge interaction is seen to be non-negligible in the eastern half of the English Channel, reaching values of 74 cm (i.e. 50% of the same event maximal storm surge) in the Dover Strait for the studied cases. This interaction decreases in westerly direction. In the risk-analysis community in France, extreme water levels have been determined assuming skew surges and tide as independent. The same hydrodynamic model is used to investigate this dependence in the English Channel. Simple computations are performed with the same meteorological forcing, while varying the tidal amplitude, and the skew surge differences DSS are analysed. Skew surges appear to be tide-dependent, with negligible values of DSS (<0.05 m) over a large portion of the English Channel, although reaching several tens of centimetres in some locations (e.g. the Isle of Wight and Dover Strait).

Idier, D.; Dumas, F.; Muller, H.

2012-12-01

441

Remote Sensing Monitoring of Tide Propagation Through Coastal Wetlands  

NASA Astrophysics Data System (ADS)

Coastal wetlands including mangrove forests and saltwater marshes are considered among the most valuable ecosystems on earth, yet their existence is presently being threatened by climate change (sea-level rise) and human interference (e.g. infrastructure development). These fragile ecosystems depend on a continuous water and nutrient replenishment by ocean tidal flow. While ocean tides are well known and forecasted, tidal flow movements through coastal wetlands are poorly known due to the fact that vegetation resists the flow and delays both inland and seaward flow at rising and subsiding tide conditions, respectively. Thus far, most observations on tide propagation through coastal wetlands have been obtained from stage (water level) measurements within the vegetated tidal zone. These stage measurements possess high temporal resolution observations, but acquired at a limited number of measurement points. Wetland InSAR (Interferometric Synthetic Aperture Radar) observations provide a new complementary source of information for detecting tidal flow in coastal wetlands, by supplying high spatial resolution maps of water level changes between two SAR acquisition times. In this study, we use InSAR observations to detect surface water level changes in response to ocean tide propagation through the coastal Everglades' mangrove forests. Interferometric processing of the data show that the highest rate of water level changes occurs near channels, as the Shark Valley River (Fig 1., center of image). These high water level gradients reflect rapid horizontal flow into and from the channel during low and high tide conditions, respectively. The high spatial resolution wetland InSAR observations provide important constraints for detailed coastal wetland flow models. RADARSAT-2 interferogram of western south Florida showing tide-induced water level changes along the transition between the saltwater mangrove marsh in the southwest and freshwater swamp in the northeast.

Wdowinski, S.; Hong, S.; Mulcan, A.; Brisco, B.

2013-05-01

442

Orbital Evolution of Planetesimals by the Galactic Tide  

NASA Astrophysics Data System (ADS)

The Oort cloud is a spherical comet reservoir surrounding the solar system. There is general agreement that the Oort cloud comets are the residual planetesimals of planet formation. The standard scenario of the Oort cloud formation consists of two dynamical stages: (1) giant planets raise the aphelia of planetesimals to the outer region of the solar system and (2) the galactic tide, passing stars, and giant molecular clouds pull up their perihelia out of the planetary region. Here we show the orbital evolution of planetesimals by the galactic tide. Planetesimals with large aphelion distances change their perihelion distances toward the outside of the planetary region by the galactic tide and become members of the Oort cloud. The effect of the galactic tide on the planetesimals with semimajor axes of ˜ 104AU is about 10-3 of the solar gravity. The timescale of the orbital evolution is ˜ 108 years. We consider only the vertical component of the galactic tide. Under the axisymmetric potential, some planetesimals may show the librations around ? (argument of perihelion)=? /2 and 3? /2 (the Kozai mechanism). The alternate increases of eccentricity and inclination of the Kozai mechanism are effective to form the Oort cloud. The secular perturbation theory demonstrates the Kozai mechanism and we can understand the motion of the planetesimals analytically. We apply the Kozai mechanism to the galactic tide and discuss the property of the Oort cloud formed by the Kozai mechanizm. This work was supported by the 21st Century COE Program Origin and Evolution of Planetary Systems of the Ministry of Education, Culture, Sports, Science, and Technology, Japan, and JSPS Research Fellowship for Young Scientists.

Higuchi, A.; Kokubo, E.; Mukai, T.

2005-05-01

443

Utility weatherization programs  

SciTech Connect

Public utility commissions (PUCs) have recently ordered or approved an increasing number of programs that install weatherization measures in residences. These programs tend to install only low-cost weatherization measures (e.g., caulking, weatherstripping, plastic storm windows, door sweeps) or major weatherization measures (e.g., insulation, storm windows, storm doors). When a program does not have income restrictions for eligibility, part of the costs are paid by the participating customer. For programs that install low-cost measures, the participant usually pays at the time of installation for the measures chosen. To require payment for major weatherization measures at the time of installation could deter participation, so these programs usually provide loans with the interest subsidized by the sponsor. Low-income customers, who have little or no disposable income, tend to shun Residential Conservation Service, loan, and other utility conservation programs that have costs to participants. Therefore PUCs have turned to programs that install weatherization measures without charge in order to reach low-income customers. This paper discusses some of the regulatory issues raised by these programs and how they have been justified by PUCs. It also gives information on cost and energy savings for 10 weatherization programs, both utility-sponsored and non-utility-sponsored, and attempts to interpret this information.

Kier, P.H.

1984-01-01

444

Cockpit weather information system  

NASA Technical Reports Server (NTRS)

Weather information, periodically collected from throughout a global region, is periodically assimilated and compiled at a central source and sent via a high speed data link to a satellite communication service, such as COMSAT. That communication service converts the compiled weather information to GSDB format, and transmits the GSDB encoded information to an orbiting broadcast satellite, INMARSAT, transmitting the information at a data rate of no less than 10.5 kilobits per second. The INMARSAT satellite receives that data over its P-channel and rebroadcasts the GDSB encoded weather information, in the microwave L-band, throughout the global region at a rate of no less than 10.5 KB/S. The transmission is received aboard an aircraft by means of an onboard SATCOM receiver and the output is furnished to a weather information processor. A touch sensitive liquid crystal panel display allows the pilot to select the weather function by touching a predefined icon overlain on the display's surface and in response a color graphic display of the weather is displayed for the pilot.

Tu, Jeffrey Chen-Yu (Inventor)

2000-01-01

445

Tide Corrections for Coastal Altimetry: Status and Prospects  

NASA Technical Reports Server (NTRS)

Knowledge of global oceanic tides has markedly advanced over the last two decades, in no small part because of the near-global measurements provided by satellite altimeters, and especially the long and precise Topex/Poseidon time series e.g. [2]. Satellite altimetry in turn places very severe demands on the accuracy of tidal models. The reason is clear: tides are by far the largest contributor to the variance of sea-surface elevation, so any study of non-tidal ocean signals requires removal of this dominant tidal component. Efforts toward improving models for altimetric tide corrections have understandably focused on deep-water, open-ocean regions. These efforts have produced models thought to be generally accurate to about 2 cm rms. Corresponding tide predictions in shelf and near-coastal regions, however, are far less accurate. This paper discusses the status of our current abilities to provide near-global tidal predictions in shelf and near-coastal waters, highlights some of the difficulties that must be overcome, and attempts to divine a path toward some degree of progress. There are, of course, many groups worldwide who model tides over fairly localized shallow-water regions, and such work is extremely valuable for any altimeter study limited to those regions, but this paper considers the more global models necessary for the general user. There have indeed been efforts to patch local and global models together, but such work is difficult to maintain over many updates and can often encounter problems of proprietary or political nature. Such a path, however, might yet prove the most fruitful, and there are now new plans afoot to try again. As is well known, tides in shallow waters tend to be large, possibly nonlinear, and high wavenumber. The short spatial scales mean that current mapping capabilities with (multiple) nadir-oriented altimeters often yield inadequate coverage. This necessitates added reliance on numerical hydrodynamic models and data assimilation, which in turn necessitates very accurate bathymetry with high spatial resolution. Nonlinearity means that many additional compound tides and overtides must be accounted for in our predictions, which increases the degree of modeling effort and increases the amounts of data required to disentangle closely aliased tides.

Ray, Richard D.; Egbert, Gary D.

2008-01-01