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1

Yaquina Bay Weather & Tides  

E-print Network

Yaquina Bay Weather & Tides Clay Creech Phil Barbour #12;HMSC Weather Station #12;Temp-Humidity Sensor at Library #12;http://weather.hmsc.oregonstate.edu #12;#12;#12;#12;#12;#12;Archived Data is Available every 15 mins. #12;#12;A pyranometer measures solar radiation #12;#12;National Weather Service

Wright, Dawn Jeannine

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

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.

Bill Finch

4

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

5

Triggering and modulation of geyser eruptions in Yellowstone National Park by earthquakes, earth tides, and weather  

USGS Publications Warehouse

We analyze intervals between eruptions (IBEs) data acquired between 2001 and 2011 at Daisy and Old Faithful geysers in Yellowstone National Park. We focus our statistical analysis on the response of these geysers to stress perturbations from within the solid earth (earthquakes and earth tides) and from weather (air pressure and temperature, precipitation, and wind). We conclude that (1) the IBEs of these geysers are insensitive to periodic stresses induced by solid earth tides and barometric pressure variations; (2) Daisy (pool geyser) IBEs lengthen by evaporation and heat loss in response to large wind storms and cold air; and (3) Old Faithful (cone geyser) IBEs are not modulated by air temperature and pressure variations, wind, and precipitation, suggesting that the subsurface water column is decoupled from the atmosphere. Dynamic stress changes of 0.1?0.2?MPa resulting from the 2002?M-7.9 Denali, Alaska, earthquake surface waves caused a statistically significant shortening of Daisy geyser's IBEs. Stresses induced by other large global earthquakes during the study period were at least an order of magnitude smaller. In contrast, dynamic stresses of >0.5?MPa from three large regional earthquakes in 1959, 1975, and 1983 caused lengthening of Old Faithful's IBEs. We infer that most subannual geyser IBE variability is dominated by internal processes and interaction with other geysers. The results of this study provide quantitative bounds on the sensitivity of hydrothermal systems to external stress perturbations and have implications for studying the triggering and modulation of volcanic eruptions by external forces.

Hurwitz, Shaul; Sohn, Robert A.; Luttrell, Karen; Manga, Michael

2014-01-01

6

Triggering and modulation of geyser eruptions in Yellowstone National Park by earthquakes, earth tides, and weather  

NASA Astrophysics Data System (ADS)

analyze intervals between eruptions (IBEs) data acquired between 2001 and 2011 at Daisy and Old Faithful geysers in Yellowstone National Park. We focus our statistical analysis on the response of these geysers to stress perturbations from within the solid earth (earthquakes and earth tides) and from weather (air pressure and temperature, precipitation, and wind). We conclude that (1) the IBEs of these geysers are insensitive to periodic stresses induced by solid earth tides and barometric pressure variations; (2) Daisy (pool geyser) IBEs lengthen by evaporation and heat loss in response to large wind storms and cold air; and (3) Old Faithful (cone geyser) IBEs are not modulated by air temperature and pressure variations, wind, and precipitation, suggesting that the subsurface water column is decoupled from the atmosphere. Dynamic stress changes of 0.1-0.2 MPa resulting from the 2002 M-7.9 Denali, Alaska, earthquake surface waves caused a statistically significant shortening of Daisy geyser's IBEs. Stresses induced by other large global earthquakes during the study period were at least an order of magnitude smaller. In contrast, dynamic stresses of >0.5 MPa from three large regional earthquakes in 1959, 1975, and 1983 caused lengthening of Old Faithful's IBEs. We infer that most subannual geyser IBE variability is dominated by internal processes and interaction with other geysers. The results of this study provide quantitative bounds on the sensitivity of hydrothermal systems to external stress perturbations and have implications for studying the triggering and modulation of volcanic eruptions by external forces.

Hurwitz, Shaul; Sohn, Robert A.; Luttrell, Karen; Manga, Michael

2014-03-01

7

Variability of the diurnal tide in the equatorial MLT  

NASA Astrophysics Data System (ADS)

For many years the amplitude of the diurnal tide in the mesosphere, lower thermosphere (MLT) has been known to be deeply modulated over a wide range of time scales. These time scales range from a few days, to seasonal dependencies, and up to interannual time scales. The causes of the variability have remained elusive, but can fall into two main categories. The first is source variability, the variability arising from variations in water vapor heating, latent heating, and ozone heating. The second potential cause is interaction of the diurnal tide with the background, including the effects of the zonal mean structure, planetary waves, gravity waves and turbulence. In this paper we focus on the second category of tidal variability. Measurements at the equator allow us to focus on particular mechanisms of tidal variability. We are close to the main sources driving the tide, equatorial convection and water vapor heating. The equatorial mean zonal winds are relatively weak so we also avoid the filtering of the tide due to the midlatitude jets. Although we cannot observe wave-mean and wave-wave interactions directly, a decadal climatology allows to diagnose how much tidal-background interaction might contribute to tidal variability. We make use of data from the SABER instrument, providing continuous temperature measurements and augment these with some equatorial radar wind observations. Two-month averages of SABER temperatures are required to unambiguously define migrating tidal temperature fields which confine our study mainly for variability on a seasonal time scale or longer. The temperature tide has a repeatable seasonal variation that is shown to stem directly from the sources and which can be observed as low as tropopause heights. Refraction and reflection are found to play an important role in the vertical structure of the tide and found to influence temporal variability in both amplitude and phase when the tide propagates into the mesosphere. An anti-symmetric migrating tidal mode was found to be present during some seasons of the year above 80 km.

Riggin, Dennis M.; Lieberman, Ruth S.

2013-09-01

8

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

9

Interannual variability of Martian weather  

Microsoft Academic Search

Pressure, temperature, imaging, and wind data from the Mutch Memorial Station, the Viking lander located in Mars' subtropics, are used to demonstrate the existence of two disctinct regimes of northern hemisphere winter weather on Mars. One of these regime is characterized by one or more intense global dust storms in which the optical depth reaches about 5 over most of

C. B. Leovy; J. E. Tillman; W. R. Guest; J. Barnes

1985-01-01

10

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

E-print Network

ARTICLE High-tide flight by wintering Dunlins (Calidris alpina): a weather-dependent trade on ocean coasts collect at high tide on roosting sites that remain above the flood line. However, some species of Calidris sandpipers spend the high-tide interval in flight over the ocean. In the winters

11

Short-term variability in the migrating diurnal tide caused by interactions with the quasi 2 day wave  

Microsoft Academic Search

Quasi 2 day wave events known to result in migrating diurnal tide variabilityWave-tide interaction simulated using TIME-GCM to understand driving mechanismsQTDW induced mean wind changes drive resolved tidal variability

Loren C. Chang; Scott E. Palo; Han-Li Liu

2011-01-01

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

Tides and Tide Prediction  

NSDL National Science Digital Library

This tide and tide prediction resource directory links to online tide predictors, tide observations/sea level measurements, tide prediction software you install to generate tide predictions on demand, and general information on tides and tide prediction.

Peter Brueggeman

1999-01-01

14

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

15

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

16

Spatial and Temporal Variability of the M2 Internal Tide Generation and Propagation on the Oregon Shelf  

E-print Network

Spatial and Temporal Variability of the M2 Internal Tide Generation and Propagation on the Oregon is implemented along the Oregon coast to study average characteristics and intermittency of the M2 internal tide the barotropic to baroclinic tide are computed from high-pass-filtered, harmonically analyzed model results

Kurapov, Alexander

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

WEATHER AND TRAFFIC CONTROLLED VARIABLE SPEED LIMITS IN SWEDEN  

Microsoft Academic Search

Summary Variable speed limits have been implemented in Sweden at 19 sites throughout the country of which 9 are weather and\\/or traffic actuated. This paper illustrates the effects for two of the road links, the weather controlled interurban motorway E6 in Halland in Western Sweden and the traffic controlled urban motorway E6 South of Gothenburg. The Halland study mainly shows

Gunnar Lind

20

Weather variability and adaptive management for rangeland restoration  

Technology Transfer Automated Retrieval System (TEKTRAN)

Inherent weather variability in upland rangeland systems requires relatively long-term goal setting, and contingency planning for partial success or failure in any given year. Rangeland plant communities are dynamic systems and successional planning is essential for achieving and maintaining system...

21

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

22

MV-WG: a new multi-variable weather generator  

NASA Astrophysics Data System (ADS)

This paper presents a new stochastic multi-variable weather generator (MV-WG) and compares its performance with LARS-WG version 4.0. Daily data of 109 meteorological stations from a North American database were used in a twofold comparison of the two generators: (1) the capability of reproducing the mean and variance of annual, seasonal and monthly values, and (2) the capability of reproducing extreme weather events were compared. Both generators did very well on imitating the mean and the variance of the monthly values of the investigated variables, but both showed a more moderate performance as far as the generation of extreme events was concerned. The three-parameter Weibull function, which is first introduced in MV-WG, was found to be a powerful tool to describe not only the distribution of the daily precipitation amounts, but also the distribution of dry and wet spell lengths, as well.

Fodor, Nándor; Dobi, Ildikó; Mika, János; Szeidl, László

2010-08-01

23

Assessment of natural climate variability using a weather generator  

NASA Astrophysics Data System (ADS)

It is common practice to use a 30-year period to derive climatological values, as recommended by the World Meteorological Organization. However this convention relies on important assumptions, of which the validity can be examined by deriving the uncertainty inherent to using a limited time-period for deriving climatological values. In this study a new method, aiming at deriving this uncertainty, has been developed with an application to precipitation for a station in Europe (Westdorpe) and one in Africa (Gulu). The weather generator framework is used to produce synthetic daily precipitation time-series that can also be regarded as alternative climate realizations. The framework consists of an improved Markov model, which shows good performance in reproducing the 5-day precipitation variability. The sub-seasonal, seasonal and the inter-annual signals are introduced in the weather generator framework by including covariates. These covariates are derived from an empirical mode decomposition analysis with an improved stability and significance assessment. Introducing covariates was found to substantially improve the monthly precipitation variability for Gulu. From the weather generator, 1,000 synthetic time-series were produced. The divergence between these time-series demonstrates an uncertainty, inherent to using a 30-year period for mean precipitation, of 11 % for Westdorpe and 15 % for Gulu. The uncertainty for precipitation 10-year return levels was found to be 37 % for both sites.

Brisson, Erwan; Demuzere, Matthias; Willems, Patrick; van Lipzig, Nicole P. M.

2015-01-01

24

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

25

The Space Weather and Ultraviolet Solar Variability (SWUSV) Microsatellite Mission  

PubMed Central

We present the ambitions of the SWUSV (Space Weather and Ultraviolet Solar Variability) Microsatellite Mission that encompasses three major scientific objectives: (1) Space Weather including the prediction and detection of major eruptions and coronal mass ejections (Lyman-Alpha and Herzberg continuum imaging); (2) solar forcing on the climate through radiation and their interactions with the local stratosphere (UV spectral irradiance from 180 to 400 nm by bands of 20 nm, plus Lyman-Alpha and the CN bandhead); (3) simultaneous radiative budget of the Earth, UV to IR, with an accuracy better than 1% in differential. The paper briefly outlines the mission and describes the five proposed instruments of the model payload: SUAVE (Solar Ultraviolet Advanced Variability Experiment), an optimized telescope for FUV (Lyman-Alpha) and MUV (200–220 nm Herzberg continuum) imaging (sources of variability); UPR (Ultraviolet Passband Radiometers), with 64 UV filter radiometers; a vector magnetometer; thermal plasma measurements and Langmuir probes; and a total and spectral solar irradiance and Earth radiative budget ensemble (SERB, Solar irradiance & Earth Radiative Budget). SWUSV is proposed as a small mission to CNES and to ESA for a possible flight as early as 2017–2018.

Damé, Luc; Meftah, Mustapha; Hauchecorne, Alain; Keckhut, Philippe; Sarkissian, Alain; Marchand, Marion; Irbah, Abdenour; Quémerais, Éric; Bekki, Slimane; Foujols, Thomas; Kretzschmar, Matthieu; Cessateur, Gaël; Shapiro, Alexander; Schmutz, Werner; Kuzin, Sergey; Slemzin, Vladimir; Urnov, Alexander; Bogachev, Sergey; Merayo, José; Brauer, Peter; Tsinganos, Kanaris; Paschalis, Antonis; Mahrous, Ayman; Khaled, Safinaz; Ghitas, Ahmed; Marzouk, Besheir; Zaki, Amal; Hady, Ahmed A.; Kariyappa, Rangaiah

2013-01-01

26

Dynamic and Regression Modeling of Ocean Variability in the Tide-Gauge Record at Seasonal and Longer Periods  

NASA Technical Reports Server (NTRS)

Comparison of monthly mean tide-gauge time series to corresponding model time series based on a static inverted barometer (IB) for pressure-driven fluctuations and a ocean general circulation model (OM) reveals that the combined model successfully reproduces seasonal and interannual changes in relative sea level at many stations. Removal of the OM and IB from the tide-gauge record produces residual time series with a mean global variance reduction of 53%. The OM is mis-scaled for certain regions, and 68% of the residual time series contain a significant seasonal variability after removal of the OM and IB from the tide-gauge data. Including OM admittance parameters and seasonal coefficients in a regression model for each station, with IB also removed, produces residual time series with mean global variance reduction of 71%. Examination of the regional improvement in variance caused by scaling the OM, including seasonal terms, or both, indicates weakness in the model at predicting sea-level variation for constricted ocean regions. The model is particularly effective at reproducing sea-level variation for stations in North America, Europe, and Japan. The RMS residual for many stations in these areas is 25-35 mm. The production of "cleaner" tide-gauge time series, with oceanographic variability removed, is important for future analysis of nonsecular and regionally differing sea-level variations. Understanding the ocean model's strengths and weaknesses will allow for future improvements of the model.

Hill, Emma M.; Ponte, Rui M.; Davis, James L.

2007-01-01

27

Tide generator  

SciTech Connect

A tidewater power system consisting of a high tide reservoir and a low tide reservoir. The high tide reservoir has an inlet adapted to be supported at high tide level and an outlet with a water wheel and generator between the outlet of the high tide reservoir and the low tide reservoir. The low tide reservoir has an outlet at the low tide level. The outlet from the high tide reservoir is adjustable to control the flow rate and the high tide reservoir can be closed at high tide to retain water for use over a period of time.

Feltenberger, B.D.

1981-06-16

28

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

29

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

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

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.

Pamela Gore

1995-08-29

32

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

2001-02-21

33

Attribution of Atlantic Multidecadal Variability to External Forcing, Internal Variability, and Weather Noise  

NASA Astrophysics Data System (ADS)

Detection of externally forced climate change and attribution of the causes of the externally forced and internally generated climate variability during the last century are the central scientific issues of current climate science and the subject of important controversies. This thesis systematically addresses fundamental problems in detection and attribution. A novel three-tier model ensemble strategy is developed and applied in the model world to address these issues. At the top tier, an ensemble of CGCMs with the same external forcing applied to each member is used to separate the results from each ensemble member into the externally forced and internally generated components. At the second tier, an ensemble of atmospheric GCMs (AGCM) with each member forced by the same SST, taken from a member of the CGCM ensemble, is used to separate the atmospheric variability in that CGCM member into SST-and-externally-forced and weather noise components. The third tier, uses an interactive ensemble version of the CGCM, in which the AGCM is replaced by an AGCM ensemble, so that atmospheric weather noise in the CGCM is suppressed. Controlled experiments forcing the interactive ensemble with the atmospheric noise diagnosed in the AGCM ensemble tier isolate the role of the weather noise in generating the internal SST variability found in the CGCM Ensemble tier. The strategy is employed to examine three important detection and attribution issues. The first is why the AGCM ensemble forced by observed SST does not simulate the observed 20th century sea level trends in the Indian Ocean. It has been suggested that this is because of an intrinsic failure of the AGCM Ensemble to correctly represent the SST forced response of the coupled system. The results show that the AGCM and CGCM ensembles are consistent with each other, and suggest that the failure to simulate the observed trends is due to model bias rather than coupling. Next, the spatial and temporal properties of the weather noise obtained from the CGCM and AGCM ensembles are examined in a preliminary fashion. This is the first attempt to document these properties. The temporal and spatial structures of the weather noise in the CGCM and AGCM simulations are very similar. The temporal structures of the noise spectra are white at timescales larger than approximately 5 months, although the noise is temporally non-Gaussian, while the spatial structures resemble those of major modes of observed climate variability. No change is detected between the statistical properties of the noise in the early and late 20th century. The Atlantic Multidecadal Variability (AMV) sea surface temperature is decomposed into externally forced and internally generated components using the CGCM ensemble, and the weather noise contribution to the internal component is isolated using the AGCM ensemble and interactive ensemble. The AMV has a strong contribution from the external 20th century forcing. The internal AMV variability is primary forced by the weather noise, but other sources of internal variability are also important. An important contribution to the internal AMV is associated with the internal variability of the oceanic Atlantic Meridional Overturning Circulation, and this contribution is distinct from the weather noise forced component.

Colfescu, Ioana

34

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

35

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

36

Graphing Tides  

NSDL National Science Digital Library

Student graphing of high and low tide from locations showing the three tide types (diurnal, semi-diurnal, and mixed) and the Bay of Fundy (tidal amplitude increased by resonance). Students recognize that not all tides are the same and that location is an important control on tides.

Martin Farley

37

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

38

Integrating Soil and Weather Data to Describe Variability in Plant Available Nitrogen  

Microsoft Academic Search

Although there are economic and environmental reasons to manage fertilizer-nitrogen (N) more effectively in variable landscapes, the impact of weather and its interaction with soil properties\\/landscape attributes or management practices has received little attention. The objectives of this study were to assess the magnitude of temporal and spatial variability in soil and plant N in a variable landscape under different

B. D. Kay; A. A. Mahboubi; E. G. Beauchamp; R. S. Dharmakeerthi

2006-01-01

39

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

40

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

41

Physical mechanisms of solar variability influence on weather and climate  

NASA Astrophysics Data System (ADS)

Numerous researches into correlation of weather and climate characteristics with solar and geomagnetic activity confirm that such correlation does exist. However there is some uncertainty in interpretation of the Sun-weather-climate relations. The paper considers the main causes of this uncertainty which are as follows - the lack of permanent monitoring data on ionizing solar EUV/X-ray radiation including periods of flares; and also the data on electron fluxes of keV energy precipitating from radiation belts first of all during geomagnetic storms; - multiplicity of Sun-weather-climate links; - the lack of understanding what are the mechanisms of solar-geomagnetic activity (flares and storms) influence on weather and climate characteristics; By now mainly the research on galactic cosmic rays (GSR) including Forbush effects and solar cosmic rays (SCR) influences on atmosphere transparence characteristics and further on climate-weather characteristics have been carried out. The GCR flux increase causes the growth of low (usually optically thick) cloudness and therefore produces in generally cooling effect on the mean surface air temperature. The appearance of SCR causes the reduction of stratospheric and tropospheric transparence and produces also usually cooling effect However these events are rare and corresponding variations of fluxes energy are small. At the same time such strong and frequent manifestations of solar activity as flares and magnetic storms are not so far taken into account since it is not known what physical mechanisms could be responsible for energy transfer from solar flares and magnetic storms to the lower atmosphere. The paper describes a novel radio-optical mechanism responsible for the solar-terrestrial links which acts as a three-stage trigger and which could be useful for solving the problem "Sun- weather-climate". This physical mechanism is based on taking into account the excitation of Rydberg states of atoms and molecules in generation of the ionospheric microwave radiation and in realization of the dissociative recombination of cluster ions in troposphere. The mechanism enables agents of solar and geomagnetic activities affect atmospheric processes with help the flux of microwaves from ionosphere. This first agent under consideration is variation of fluxes of solar EUV and X -ray radiation during flares. The second agent is fluxes of electrons and protons which precipitate from radiation belts as a result of geomagnetic storms.. Our novel radiooptical trigger mechanism of influence of solar and geomagnetic activity on the formation of weather and climate changes consists of three stages. The first stage is an increase in generation of the microwave radiation which penetrates from the ionosphere to the earth surface. The microwave radiation arises from the transitions between Rydberg states which are exited by the energetic ionospheric electrons namely photoelectrons, secondary electrons and Auger electrons. The second stage is a change in the proportion of water vapour to water clusters caused by increased microwave radiation. The third stage is a change of the atmosphere transparence in the absorption bands of water vapour and clusters and appearance of optically-thin clouds at high and middle altitudes. These clouds cause a net warming due to their relative transparency at short wavelengths but opacity in the IR region The atmosphere transparence determines the fluxes of solar irradiance coming down as well as flux of the thermal radiation coming out from the underlying surface. We emphasize that all stages of the proposed mechanism are experimentally confirmed: the microwave ionospheric emission, which intensifies during solar and magnetic storms, was detected; the regulation of humidity at altitude higher than 2 km by the solar microwave emission and during of solar flares was registered; a direct influence of solar flares and magnetic storms on the total cloudiness is distinctly registered at least in some geographic areas.

Avakyan, Sergei

2010-05-01

42

High-latitude oceanic variability associated with the 18. 6-year nodal tide  

SciTech Connect

Ocean temperatures in the upper 250 m in the northern North Pacific (60[degree]N, 149[degree]W) increased by more than 1[degree]C from 1972 to 1986 but are now decreasing. Subsurface temperature anomalies are well correlated ([approx] 0.58) with the air temperature anomalies at Sitka, Alaska; hence the coastal air temperatures can be used as a proxy data set to extend the ocean temperature time series back to 1828. Up to 30% of the low-frequency variance can be accounted for with the 18.6-year nodal signal. Additionally, spectral analysis of these air temperature variations indicates a significant low-frequency peak in the range of the 18.6-year signal. Similar low-frequency signals have been reported for Hudson Bay air temperatures since 1700, for sea surface temperatures in the North Atlantic from 1876 to 1939, and for sea level in the high-latitude southern hemisphere. The water column temperature variations presented here are the first evidence that the upper ocean is responding to this very long period tidal forcing. An enhanced high-latitude response to the 18.6-year forcing is predicted by equilibrium tide theory, and it should be most evident at latitudes poleward of about 50[degree]. These low-frequency ocean-atmosphere variations must be considered in high-latitude assessments of global climate change, since they are of the same magnitude as many of the predicted global changes. 29 refs., 5 figs., 2 tabs.

Royer, T.C. (Univ. of Alaska, Fairbanks (United States))

1993-03-15

43

Earth tides  

SciTech Connect

Nineteen papers on gravity, tilt, and strain tides are compiled into this volume. Detailed chapters cover the calculation of the tidal forces and of the Earth's response to them, as well as actual observations of earth tides. Partial Contents: On Earth tides. The tidal forces: Tidal Forces. New Computations of the Tide-Generating Potential. Corrected Tables of Tidal Harmonics. The Theory of Tidal Deformations. Body Tides on an Elliptical, Rotating, Elastic and Oceanless Earth, Deformation of the Earth by Surface Loads. Gravimetric Tidal Loading Computed from Integrated Green's Functions. Tidal Friction in the Solid Earth. Loading Tides Versus Body Tides. Lunar Tidal Acceleration from Earth Satellite Orbit Analysis. Observations: gravity. Tidal Gravity in Britain: Tidal Loading and the Spatial Distribution of the Marine Tide. Tidal Loading along a Profile Europe-East Africa-South Asia-Australia and the Pacific Ocean. Detailed Gravity-Tide Spectrum between One and Four Cycles per Day. Observations: tilt and strain. Cavity and Topographic Effects in Tilt and Strain Measurement. Observations of Local Elastic Effects on Earth Tide Tilts and Strains.

Harrison, J.C.

1984-01-01

44

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

45

Weather  

NSDL National Science Digital Library

In the project you will learn about thunderstorms and tornadoes and play a weather matching game. What exactly are thunderstorms and tornadoes? Use your T- chart to explain some facts about a thunderstorm and a tornado as we review each. T-Chart Begin by reviewing what a thunderstorm is and how they form. Thunderstorm information What is a thunderstorm? What are thunderstorms most likely to occur? What causes thunder? Next review what a tornado ...

Caitlin, Ms.

2009-10-21

46

Weather on other worlds: BD variability and the VVV  

NASA Astrophysics Data System (ADS)

Various evidences point to the presence of clouds in ultra-cool atmospheres. An important ambiguity remains as to whether all variability in ultra-cool dwarfs is caused by patchy clouds, or other fenomena like magnetic activity and auroras. Simultaneous multi-wavelength photometric and/or spectroscopic monitoring could help to reveal this enigma.

Kurtev, R.; Metchev, S.; Heinze, A.; Gromadzki, M.; Ivanov, V. D.; Minniti, D.; Beamin, J. C.; Borissova, J.

2014-10-01

47

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

2014-12-01

48

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.

49

Rainfall Generator for the Rhine Basin Multi-site generation of weather variables  

E-print Network

Rainfall Generator for the Rhine Basin Multi-site generation of weather variables for the entire generator for the Rhine Basin 38 3 #12;Summary This is the final report of a project on the development of a rainfall generator for the Rhine basin. The request for this generator arose from the need to study

Stoffelen, Ad

50

EFFECTS OF WEATHER-CONTROLLED VARIABLE SPEED LIMITS ON INJURY ACCIDENTS  

Microsoft Academic Search

SUMMARY A study was conducted on the impacts of weather-controlled variable speed limit systems on injury accidents. The high quality systems which based the control on automatic classification of road condition situations and which used fibre optic or LED signs decreased the injury accident risk in winter by 13% and in summer by 2%. For the other group of systems

Pirkko Rämä; Anna Schirokoff

51

Weather data, site variability, and probabilities of success: a practical perspective on adaptive management  

Technology Transfer Automated Retrieval System (TEKTRAN)

Arid and semi-arid rangelands occupy over half of the earth’s surface and are characterized by high variability in seasonal and annual precipitation. Invasive plants compete for soil and water and exacerbate inherent weather limitations for desirable plant establishment. Management guidelines for ...

52

Weather variability, ecological processes and optimization of soil micro-environment for rangeland restoration  

Technology Transfer Automated Retrieval System (TEKTRAN)

Arid and semi-arid rangelands occupy over half of the earth’s surface and are characterized by relatively high variability in seasonal and annual patterns of precipitation. Invasive plants compete for soil and water resources and exacerbate inherent weather limitations for native plant establishmen...

53

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

54

Low frequency North Atlantic SST variability: Weather noise forcing and coupled response  

NASA Astrophysics Data System (ADS)

A method to diagnose the causes of low frequency SST variability is developed, tested and applied in an ideal case and real climate. In the ideal case, a free simulation of the COLA CGCM is taken as synthetic observations. For real climate, we take NCEP reanalysis atmospheric data and Reynolds SST as observations. Both the synthetic and actual observation data show that weather noise is the main component of atmospheric variability at subtropics and high-latitude. Diagnoses of results from the ideal case suggest that most of the synthetic observed SST variability can be reproduced by the weather noise surface fluxes forcing. This includes the "observed" low frequency SST patterns in the North Atlantic and their corresponding time evolution. Among all the noise surface fluxes, heat flux plays a major role. The results from simulations using actual observations also suggest that the observed SST variability is mostly atmospheric weather noise forced. The regional atmospheric noise forcing, especially the heat flux noise forcing, is the major source of the low frequency SST variability in the North Atlantic. The observed SST tripole mode has about a 12 year period and it can be reasonably reproduced by the weather noise forcing in terms of its period, spatial pattern and variance. Based on our diagnosis, it is argued that the SST tripole is mainly forced by local atmospheric heat flux noise. The gyre circulation plays a secondary role: the anomalous gyre circulation advects mean thermal features across the inter-gyre boundary, and the mean gyre advection carries SST anomalies along the inter-gyre boundary. The diagnosis is compared with a delayed oscillator theory. We find that the delayed oscillator theory is not supported and that the SST tripole mode is forced by weather noise heat flux noise. However, the result may be model dependent.

Fan, Meizhu

55

The Spatial Variability of Weathering Processes in a Peruvian River System  

NASA Astrophysics Data System (ADS)

The role of floodplains in the weathering of sediment exported from mountainous regions is poorly understood and has the potential to play a significant role in the overall weathering budget of large river systems. While high rates of floodplain weathering have been measured in the Himalayan system [1], there are conflicting results concerning the importance of floodplain weathering in the Amazon system [2-3]. To address this issue, the dissolved major element chemistry of the Kosñipata-Madre de Dios river system in Peru was measured monthly in nested catchments spanning the headwater-floodplain transition in order to determine spatially-resolved weathering rates and to examine any associated changes in weathering processes. Analysis of the dissolved major element data reveals a change in the dominant weathering process controlling the Ca2+ and Mg2+ fluxes associated with the headwater-floodplain transition. Based on (Ca2+ + Mg2+) / HCO3- ratios near 0.5, Ca2+ and Mg2+ fluxes in the floodplain are controlled by carbonate dissolution by carbonic acid. In the Andean catchments, variable (Ca2+ + Mg2+) / HCO3- ratios, (Ca2+ + Mg2+) / SO42- ratios near 1, and high SO42- concentrations suggest that either carbonate dissolution by sulfuric acid or sulfate mineral dissolution is the main control on Ca2+ and Mg2+ fluxes. This observed change is significant as it has important implications for the net consumption of CO2 by silicate weathering in this river system. [1] West, AJ et al, 2002, Geology 30: 355-358, [2] Gaillardet, J et al, 2006, Geochim. Cosmochim. Acta 70: 189, [3] Moquet, J et al, 2011, Chem. Geol 287: 1-26

Torres, M. A.; Ballew, N.; Clark, K.; West, A.

2011-12-01

56

Weather variability permitted within amphibian monitoring protocol and affects on calling Hylidae.  

PubMed

Anuran populations are sensitive to changing environmental conditions and act as useful indicators. Presently, much information collected concerning frog populations comes from volunteers following the North American Amphibian Monitoring Protocol. Does weather variability allowed within protocol affect the abundance of calling frogs? For 10 years, Credit Valley Conservation (Ontario, Canada) has been collecting anuran data concerning nine frog species employing three frog monitoring runs. Records include frog abundance by protocol code and five weather variables. Antecedent precipitation and temperature were determined from the nearest weather station. Locations with large source populations of two Hylidae species were selected (spring peeper calling in April and gray tree frog in May). Spearman correlations suggested there were no significant relationships between calling abundance of Hylidae species and ambient wind speed or humidity. However, gray tree frogs were temperature sensitive and calling was significantly related to increased water and air temperatures as well as day time high temperatures over the previous 2 weeks. Both species of calling Hylidae were affected by the volume and timing of precipitation (though, in different ways). Gray tree frogs seem to prefer drier conditions (when temperatures are significantly warmer) while spring peepers prefer to call during, or closely following, precipitation. Monitors targeting gray tree frog should track local weather conditions and focus on evenings when it is (a) warmer than the minimum temperatures and (b) drier than suggested by the protocol. It is recommended that an additional monitoring run could be added to reduce detection variability of this species. PMID:23625355

Milne, Robert; Bennett, Lorne; Hoyle, Mathew

2013-11-01

57

Influence of environmental and prey variables on low tide shorebird habitat use within the Robbins Passage wetlands, Northwest Tasmania  

NASA Astrophysics Data System (ADS)

Shorebirds feed primarily on tidal flats, and their distribution over these flats is influenced by their prey and abiotic factors. These factors act by influencing the distribution and abundance of the prey, or the shorebirds ability to exploit it. The aims of this study were to investigate the low tide foraging distribution of shorebirds at four sites within the Robbins Passage wetlands, and the environmental and invertebrate factors that may influence their distribution. The greatest densities and number of shorebirds were found at Shipwreck Point and East Inlet. The shorebirds within-site distribution was also non-random, with the shorebirds present in greatest densities at the water's edge and low intertidal stratum, although this varied among species. Generally, on a small spatial scale, invertebrate diversity was positively correlated, and seagrass leaf mass was negatively correlated, with shorebird feeding density. On a large spatial scale, invertebrate biomass and seagrass root mass were positively correlated with shorebird feeding density. Invertebrate biomass and seagrass root mass explained 71% of the variance in total shorebird feeding density on the tidal flats. The variation in shorebird feeding density and diversity was therefore partly explained by invertebrate diversity and biomass, as well as the environmental factors seagrass roots and leaf mass and tidal flat area, although the strength of these relationships was influenced by the two different spatial scales of the study. The strength of the relationships between shorebird feeding density and the invertebrate and environmental variables was stronger on a large spatial scale. The presence of seagrass may have influenced shorebird-feeding density by affecting the invertebrate abundance and composition or the shorebirds ability to detect and capture their prey. The area of the tidal flat had opposing effects on the shorebird species. These results can be used to assist in the development of management plans for the Robbins Passage wetlands and the conservation of important shorebird areas.

Spruzen, Fiona L.; Richardson, Alastair M. M.; Woehler, Eric J.

2008-06-01

58

Long-term variabilities of lunar semi-diurnal tide in low-latitude mesospheric winds and equatorial electrojet and their relationship with polar stratospheric warming  

NASA Astrophysics Data System (ADS)

Atmospheric tides play a vital role in causing variabilities, in particular, of equatorial mesosphere, lower thermosphere and ionosphere (MLTI) region. They are exited either thermally by solar heating or gravitationally by lunar and solar gravitational fields. Lunar tides in the atmosphere are generated in the lower atmosphere primarily due to Moon’s gravitational acceleration and vertical motion of the Earth and ocean at the lower boundary of the atmosphere. Recent interest has emerged to understand the possible connection between stratospheric warming and enhanced lunar tidal perturbation in the equaotrial ionosphere. In the present work, nine years (2004-2012) of long-term MLT wind observations obtained by using the medium frequency (MF) radar at Tirunelveli (8.7oN, 77.8oE) are used to study the tidal variabilities during the recent sudden stratospheric warming (SSW) events. The EEJ strength is derived from the differences between the magnetic field variations in the horizontal field obtained from Tirunelveli (8.7oN, 77.8oE) and Alibag (ABG) (18.6o N, 72.9o E). An interesting result of the present study is that there is an unusual enhancement of lunar semidiurnal tidal amplitude in meridional component and also in EEJ strength during the SSW events 2006 and 2009. The preliminary result suggests that the enhancement of lunar tide could be due to changes in underlying background winds due to the occurrence of SSW. As the equatorial ionospheric currents appear to be driven by the lunar semidiurnal tide during the SSW events, they play a major role in coupling neutral atmosphere and ionosphere.

Sundararaman, Sathishkumar; Gurubaran, Subramanian; Sundhararajan, Sridharan

59

The sensitivity of the epidemic growth rate to weather variables, with an application to yellow rust on wheat.  

PubMed

ABSTRACT We first show how to estimate the exponential epidemic growth rate, r, for different combinations of three weather variables. Then we derive a method to quantify the sensitivity of r to a weather variable as a function of the pathogen life cycle variables of latent period, basic reproductive number, and the mean and standard deviation of the sporulation curve. The method can be used to identify the most important weather variable and pathogen life cycle component in terms of epidemic progress. The method is applied to yellow rust, caused by Puccinia striiformis, on winter wheat. We conclude that the most important weather variable for the progress of yellow rust is temperature, followed by dew period and light quantity. By far, the most important pathogen life cycle component is the basic reproductive number, especially at low and high temperatures. This disagrees with the general view that latent period is the most important variable at low temperatures. We discuss explanations of this. PMID:18944376

Papastamati, Konstantina; van den Bosch, Frank

2007-02-01

60

Tropical Ocean Surface Energy Balance Variability: Linking Weather to Climate Scales  

NASA Technical Reports Server (NTRS)

Radiative and turbulent surface exchanges of heat and moisture across the atmosphere-ocean interface are fundamental components of the Earth s energy and water balance. Characterizing the spatiotemporal variability of these exchanges of heat and moisture is critical to understanding the global water and energy cycle variations, quantifying atmosphere-ocean feedbacks, and improving model predictability. These fluxes are integral components to tropical ocean-atmosphere variability; they can drive ocean mixed layer variations and modify the atmospheric boundary layer properties including moist static stability, thereby influencing larger-scale tropical dynamics. Non-parametric cluster-based classification of atmospheric and ocean surface properties has shown an ability to identify coherent weather regimes, each typically associated with similar properties and processes. Using satellite-based observational radiative and turbulent energy flux products, this study investigates the relationship between these weather states and surface energy processes within the context of tropical climate variability. Investigations of surface energy variations accompanying intraseasonal and interannual tropical variability often use composite-based analyses of the mean quantities of interest. Here, a similar compositing technique is employed, but the focus is on the distribution of the heat and moisture fluxes within their weather regimes. Are the observed changes in surface energy components dominated by changes in the frequency of the weather regimes or through changes in the associated fluxes within those regimes? It is this question that the presented work intends to address. The distribution of the surface heat and moisture fluxes is evaluated for both normal and non-normal states. By examining both phases of the climatic oscillations, the symmetry of energy and water cycle responses are considered.

Roberts, J. Brent; Clayson, Carol Anne

2013-01-01

61

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.

Kumar Mahadevan

62

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

63

Effects of soil variability and weather conditions on pesticide leaching--a farm-level evaluation.  

PubMed

In line with European regulations, Dutch law imposes an environmental threshold of 0.1 microg L(-1) on pesticide concentrations in ground water. During registration, the risk of exceeding this threshold is assessed through simulations for one or a few standard scenarios that do not reflect spatial variability under field conditions. The introduction of precision agriculture, where soil variability is actively managed, can increase control over pesticide leaching. This study presents a step-wise evaluation of the effects of soil variability and weather conditions on pesticide leaching. The evaluation was conducted on a 100-ha arable farm and aimed at identifying opportunities for precision management. As a first step, a relative risk assessment identified pesticides presenting a relatively high risk to the environment. Second, the effect of weather conditions was analyzed through 20 years of simulations for three distinct soil profiles. Results were summarized in cumulative probability plots to provide a probabilistic characterization of historical weather data. The year matching 90% probability (1981) served as a reference to simulate pesticide leaching from 612 soil profiles. After interpolation, areas where concentrations exceeded the environmental threshold were identified. Out of a total of 19 pesticides, isoproturon [N-dimethyl-N'-(4-(1-methylethyl)phenyl)urea], metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H)-one], and bentazon [2,1,3-benzothiadiazin-4(3H)-one, 3-isopropyl-, 2,2-dioxide] showed the highest risk for leaching. Leaching was strongly affected by soil variability at the within-field, field, and farm levels. Opportunities for precision management were apparent, but depended on the scale level at which environmental thresholds were implemented. When legislation is formulated in this issue, the presented step-wise evaluation can serve as a basis for identification and precision management of high-risk pesticides. PMID:12026082

van Alphen, B J; Stoorvogel, J J

2002-01-01

64

Tropical influenza and weather variability among children in an urban low-income population in Bangladesh  

PubMed Central

Background Influenza seasonality in the tropics is poorly understood and not as well documented as in temperate regions. In addition, low-income populations are considered highly vulnerable to such acute respiratory disease, owing to limited resources and overcrowding. Nonetheless, little is known about their actual disease burden for lack of data. We therefore investigated associations between tropical influenza incidence and weather variability among children under five in a poor urban area of Dhaka, Bangladesh. Design Acute respiratory illness data were obtained from a population-based respiratory and febrile illness surveillance dataset of Kamalapur, a low-income urban area in southeast Dhaka. Analyzed data were from January 2005 through December 2008. Nasopharyngeal wash specimens were collected from every fifth eligible surveillance participant during clinic visits to identify influenza virus infection with viral culture and reverse transcriptase–polymerase chain reaction. Time series analysis was conducted to determine associations between the number of influenza cases per week and weather factors. Zero-inflated Poisson and generalized linear Poisson models were used in the analysis for influenza A and B, respectively. Results Influenza A had associations with minimum temperature, relative humidity (RH), sunlight duration, and rainfall, whereas only RH was associated with influenza B. Although associations of the other weather factors varied between the two subtypes, RH shared a similar positive association when humidity was approximately 50–70%. Conclusions Our findings of a positive RH association is consistent with prior studies, and may suggest the viral response in the tropics. The characteristics of settlement areas, population demographics, and typical overcrowding of urban poverty may also contribute to different impacts of rainfall from higher economic population. Further investigations of associations between tropical influenza and weather variability for urban low-income populations are required for better understanding. PMID:25128806

Imai, Chisato; Brooks, W. Abdullah; Chung, Yeonseung; Goswami, Doli; Anjali, Bilkis Ara; Dewan, Ashraf; Kim, Ho; Hashizume, Masahiro

2014-01-01

65

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

66

The "Mars-Sun Connection" and the Impact of Solar Variability on Mars Weather and Climate  

NASA Astrophysics Data System (ADS)

We develop the scientific case to measure simultaneously the UV and near-UV solar irradiance incident on the Mars atmosphere and at the Martian surface, to explore the effects and influence of Solar variability and "Space Weather" on Mars weather and climate, its implications for life, and the implications for astronaut safety on future manned Mars missions. The UV flux at the Martian surface is expected to be highly variable, due to diurnal, daily, and seasonal variations in opacity of atmospheric dust and clouds, as well as diurnal and seasonal variations in ozone, water vapor and other absorbing species. This flux has been modeled (Kuhn and Atreya, 1979), but never measured directly from the Martian surface. By directly observing the UV and near UV solar irradiance both at the top of the atmosphere and at the Martian surface we will be able to directly constrain important model parameters necessary to understand the variations of atmospheric dynamics which drive both Mars weather and climate. Directly measuring the solar UV radiation incident upon the Mars atmosphere and at the Martian surface also has important implications for astronaut safety on future manned Mars missions. The flux at the surface of Mars at 250 nm is also believed to be approximately 3000 times greater than that on Earth. This presents potential hazards to future human explorers as well as challenges for future agriculture such as may be carried out in surface greenhouses to provide food for human colonists. A better understanding of the surface flux will aid in designing appropriate protection against these hazards.

Hassler, D. M.; Grinspoon, D.

2004-05-01

67

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

NASA Astrophysics Data System (ADS)

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.

Brown, Iain

2013-07-01

68

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

69

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

70

Interannual variability of the nonmigrating semidiurnal tide at high latitudes and stationary planetary wave in the opposite hemispheres  

NASA Astrophysics Data System (ADS)

The westward propagating zonal wavenumber 1 nonmigrating semidiurnal tide (SW1) enhanced at high latitudes during summer in the mesosphere and lower thermosphere (MLT) is believed to originate from the nonlinear interaction between the migrating semidiurnal tide (SW2) and the stationary planetary wave zonal wavenumber 1 (SPW1) in the opposite winter hemispheres. This paper presents correlations of the SW1 over the Antarctic and Arctic and the SPW1 in the opposite hemispheres. The SW1 is determined from horizontal wind measurements by the TIMED Doppler Interferometer (TIDI) and the SPW1 is from temperature measurements by the Sounding the Atmosphere using Broadband Emission Radiometry (SABER), both aboard the NASA's Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite. We focus on the SW1 over the Antarctic and the SPW1 in the northern hemisphere during an interval from mid-September to mid-November, and the SW1 over the Arctic and the SPW1 in the southern hemisphere during an interval from mid-March to mid-May. Large interannual variations of the SW1 and SPW1 are exhibited in both northern and southern hemispheres. For amplitudes of the SW1 at 90 km and 82.5°S, positive correlations are exhibited with SPW1 amplitudes at ~55 km in the equatorial region, and ~25 km and 55°N. Although zonal SW1 amplitude at 95 km and 86.5°N is positively correlated with SPW1 amplitudes at ~30°S above 35 km, meridional SW1 amplitude is negatively correlated with SPW1 amplitudes equatorward of 30°S. We also present results of a correlation analysis for SW3 amplitudes during an interval from mid-January to mid-March over the Antarctic and from mid-July to mid-September over the Arctic with SPW1 amplitudes.

Iimura, H.; Fritts, D. C.; Lieberman, R. S.; Wu, Q.; Skinner, W. R.

2014-04-01

71

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

2011-01-01

72

Spatial and temporal wind variability over Spain and its relationship with synoptic weather types  

NASA Astrophysics Data System (ADS)

The knowledge of the spatial and temporal variability of the wind over a given area is crucial for multiple purposes, like wind power generation, pollutant dispersion, risk evaluation, hydrological processes, etc. On the other hand, the assessment of the synoptic conditions related to wind behavior can be very useful for several applications. In the framework of wind power, integrating the effects of large-scale on wind behavior could improve the scheduling of the power generation, as well as to avoid damage in wind turbines due to extreme wind events. In this work, we present a methodology which contributes to the improvement in wind energy profits manly in two aspects. By one hand, performing an objective wind regionalization of an extensive area allows the identification of complementary regions. On the other hand, the association of wind field to WT can be used as a convenient tool for medium-range weather forecast, as well as to perform future wind projections under different climate change scenarios. We have analyzed the wind variability using a network of 448 wind observations evenly distributed over Spain (except Canary Islands). The first step was to obtain regions with similar temporal behavior. This was performed by using a clustering method based on the main principal modes of variability, obtained through PCA analysis. The hierarchical Ward`s method is used to provide the initial seeds to a subsequent no-hirarchical k-means method. The analysis was carried out for daily mean series of wind speed encompassing the period 2001-2007, considering each season separately. The number of regions obtained with a similar wind speed behaviour depends on the season (8 in winter, 7 in spring, 6 in summer and autumn, and 13 for the whole year). The common regions in all seasons can be roughly associated to the following areas: High Ebro Valley, Low Ebro Valley, the Mediterranean Basin, the Guadalquivir Valley, the Cantabrian Coast and the Iberian Plateaus. It is found that, in some seasons, some of these areas exhibit no correlation or even are anticorrelated to others. In a second step, the mean spatial regional series are related to the synoptic conditions. The Weather Types (WT) classification used (García-Valero et al, 2012) consist on 12 WT for each season, accounting for SLP and Z500 obtained from ERA40 reanalysis and ECMWF analysis. The wind climatology of every region is associated to each WT. Therefore, the weather situations involving extreme events, calms or regular winds are characterized.

Lorente-Plazas, R.; Montavez, J. P.; García-Valero, J. A.; Gómez-Navarro, J. J.; Jerez, S.; Baró, R.; Jiménez, P. A.; Jiménez-Guerrero, P.

2012-04-01

73

Predicting trauma admissions: the effect of weather, weekday, and other variables.  

PubMed

One of the challenges all hospitals, especially designated trauma centers, face is how to make sure they have adequate staffing on various days of the week and at various times of the year. A number of studies have explored whether factors such as weather, temporal variation, holidays, and events that draw mass gatherings may be useful for predicting patient volume. This article looks at the effects of weather, mass gatherings, and calendar variables on daily trauma admissions at the three Level I trauma hospitals in the Minneapolis-St. Paul metropolitan area. Using ARIMA statistical modeling, we found that weekends, summer, lack of rain, and snowfall were all predictive of daily trauma admissions; holidays and mass gatherings such as sporting events were not. The forecasting model was successful in reflecting the pattern of trauma admissions; however, it's usefulness was limited in that the predicted range of daily trauma admissions was much narrower than the observed number of admissions. Nonetheless, the observed pattern of increased admission in the summer months and year-round on Saturdays should be helpful in resource planning. PMID:20069999

Friede, Kevin A; Osborne, Marc C; Erickson, Darin J; Roesler, Jon S; Azam, Arsalan; Croston, J Kevin; McGonigal, Michael D; Ney, Arthur L

2009-11-01

74

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

75

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

76

Control of equatorial ionospheric morphology by atmospheric tides  

Microsoft Academic Search

A newly discovered 1000-km scale longitudinal variation in ionospheric densities is an unexpected and heretofore unexplained phenomenon. Here we show that ionospheric densities vary with the strength of non-migrating, diurnal atmospheric tides that are, in turn, driven mainly by weather in the tropics. A strong connection between tropospheric and ionospheric conditions is unexpected, as these upward propagating tides are damped

T. J. Immel; E. Sagawa; S. L. England; S. B. Henderson; M. E. Hagan; S. B. Mende; H. U. Frey; C. M. Swenson; L. J. Paxton

2006-01-01

77

The origin of tides  

NSDL National Science Digital Library

This QuickTime animation points out how the pull of gravity results in the tides. A high tide results on the near side of the Earth-moon alignment. The bulge on the opposite side results as the solid earth is pulled away from water on its far side where the moon?s gravitational pull is weakest. These two high tide bulges stay in place as the earth rotates, leading to two high tides and two low tides every day.

McGraw-Hill

78

Forecasting the Coastal Ocean: Resolution, Tide, and Operational Data in the South Atlantic Bight  

E-print Network

Forecasting the Coastal Ocean: Resolution, Tide, and Operational Data in the South Atlantic Bight D on the shelf occurs in this mode, in the tide- and weather-bands. The former is completely a remotely agreement with oceanic tides over the whole East Coast; (ADCIRC 1995); and quality data along the coast (NOS

79

Forecasting the Coastal Ocean: Resolution, Tide, and Operational Data in the South Atlantic Bight  

E-print Network

Forecasting the Coastal Ocean: Resolution, Tide, and Operational Data in the South Atlantic Bight D motion on the shelf occurs in this mode, in the tide- and weather-bands. The former is completely agreement with oceanic tides over the whole East Coast; (ADCIRC 1995); and quality data along the coast (NOS

80

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

81

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.

82

Introduction to Ocean Tides  

NSDL National Science Digital Library

Ocean tides profoundly impact coastal maritime operations. This module provides an introduction to the origin, characteristics, and prediction of tides. After introducing common terminology, the module examines the mechanisms that cause and modify tides, including both astronomical and meteorological effects. A discussion of tide prediction techniques and products concludes the module. This module includes rich graphics, audio narration, embedded interactions, and a companion print version.

COMET

2006-09-22

83

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

84

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.

Michael Passow

85

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

86

Relationship between Pollen Counts and Weather Variables in East-Mediterranean Coast of Turkey  

PubMed Central

Background: Aeroallergen sampling provides information regarding the onset, duration and severity of the pollen season that clinicians use to guide allergen selection for skin testing and treatment. Objectives: This atmospheric survey reports (1) airborne pollen contributions in Adana in one-year period (2) pollen onset, duration and peak level (3) the relationship between airborne pollen and selected meteorological variables and; (4) effects on symptoms in pollen allergic children. Methods: Pollen sampling was performed with a volumetric Burkard Spore Trap. Meteorological data were measured daily from April 2001 to April 2002. Asthma symptom scores were investigated in 186 pollen allergic children that were on follow up in pediatric allergy outpatient clinics during same period. Results: Average measurements included 82.5% tree pollen, 7.7% grass pollen and 9.8% herb pollen 54 taxa were identified during one year. The most prominent tree pollens were Cupressaceae, Eucalyptus and Pinus. The most common herb was Chenopodiaceae pollen family. When airborne pollen levels were examined in relation to single meteorological conditions; daily variations in total pollen counts were not significantly correlated with any variable studied (humidity, rainfall, temperature and wind) (p>0.05). On the other hand, statistically significant relationship between pollen concentration and symptom scores were found (p>0.05). Positive correlations were seen between both Gramineae and Herb pollen, and humidity and rainfall from March to July. However, positive correlations were detected between tree pollen counts and temperature and humidity in May and June. Conclusion: This survey is the first volumetric airborne pollen analysis conducted in the survey area in Adana. This study suggested that the effects of weather on pollen count and symptom scores in this population could not be clearly identified with the evaluation of one-year data. However, pollen counts had effect on allergic symptoms in pollen allergic children. Examination of the complex interaction of multiple whether parameters would perhaps more fully elucidate the relationship between meteorology and aerobiology and provide the clinician with information necessary to forecast pollen prevalence. An awareness of the ever chancing, local aeroallergen patterns requires regular monitoring. Such awareness serves as a useful guide in the effective testing and treatment of atopic patients. PMID:15154617

Karakoç, Gülbin Bingöl; Yilmaz, Mustafa; Pinar, Münevver; Kendirli, Seval Güneçer; Çakan, Halil

2004-01-01

87

a Study of Risk Preferences and Perceptions of Weather Variability of Smallholder Subsistence Farmers in Malawi  

NASA Astrophysics Data System (ADS)

In 2011, the global population reached seven billion people. According to Foley et al. (2011) nearly one billion still suffer from chronic hunger. World population is expected to increase by another 9-11 billion by 2050. As demand for food grows, the world food system faces three primary challenges: to ensure that the current population of seven billion is adequately fed, to double food production to meet future population growth, and to achieve both in an environmentally sustainable way. As pressures on the global food system grow, sub-Saharan presents a special set of opportunities and challenges. In parts of sub-Saharan Africa, smallholder adoption of productivity-increasing agricultural technologies has proved a pervasive challenge and staple grain yields in the region lag significantly behind the rest of the world. National policies and internationally-funded initiatives such as the Alliance for a Green Revolution in Africa (AGRA) have proposed to close the agricultural yield gap through promotion of small farmer adoption of technologies that increase production efficiency, such as improved seeds, fertilizer and irrigation. However, research has found that even when these productivity-enhancing technologies are provided at subsidized costs, many projects report take-up rates well below 100%. In order to understand why farmers are not making investments to improve staple crop yields, it is critical to investigate the nature of the problem of the low take-up rate. Possible hypotheses include: credit constraints, opportunity costs, and farmer risk and/or time preferences that lead them to delay investment. Our project in Mwandama, Malawi uses techniques from prospect theory and expected utility theory to provide insight into farmer decision-making around technology adoption. We build on past research conducted in Ethiopia, India and Uganda, which has found that poor farmers systematically underweight the likelihood of good outcomes. We use a new methodology called parametric Dynamic Experiments for Estimating Preferences developed at Columbia University to measure three prospect theory parameters using an adaptive survey tool installed on a tablet PC. Our work is the first to use an adaptive survey tool to measure risk preferences and to combine these measures with both panel data on agricultural investments and beliefs about climate change using scenarios. Despite the need for better understanding of how farmer preferences over time and risk might influence technology adoption and production decisions made by farmers in sub-Saharan Africa, there is a critical gap in research about this topic. Whether and how vulnerability to climate change has entered the mind frame of farmers is explored with a scenario setup, in which farmers are asked to provide advice to a hypothetical farmer facing low yields due to a prolonged drought. Farmer responses to the scenarios give us information about both the channel through which farmers receive information about agriculture and adaptation and primary factors mentioned to be important agricultural strategies in the face of increasingly unpredictable weather patterns. This research offers insights to understand decision-making process of smallholder farmers, who face adverse effects of weather variability and the present problem of low soil fertility.

Yoon, S.; Michelson, H. C.

2013-12-01

88

MST radar detection of middle atmosphere tides  

NASA Technical Reports Server (NTRS)

Meteorological and dynamical requirements pertaining to the specification of middle atmosphere tides by the MST radar technique are outlined. Major issues addressed include: (1) the extraction of tidal information from measurements covering a fraction of a day; (2) the ramifications of transient effects (tidal variability) on the determination and interpretation of tides; (3) required temporal and spatial resolutions and; (4) global distributions of MST radars, so as to complement existing MST, meteor wind, and partial reflection drift radar locations.

Forbes, J. M.

1983-01-01

89

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

90

Neural Network Approach to variable vehicle speed limitation upon weather conditions  

Microsoft Academic Search

The target of this research is to adapt a Neural Network Approach that could be used in determining proper vehicle speed upon relevant conditions data. These include weather condition such as: Precipitation intensity, speed of wind, and degree of visibility, and road surface condition. Data are input to neural network. Output driven is a decision about allowed (advised) speed of

Maged M. M. Fahmy

2008-01-01

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

Tides in the atmosphere  

Microsoft Academic Search

Tides in the water are important for any kind of human activities at sea. They have a periodic structure caused by solar and\\u000a lunar gravitational forces; the levels of the tides are provided everywhere along coastlines. Tables of tidal levels contain\\u000a forecasted levels of tides and are of extreme importance. The atmosphere is considered a fifth ocean, and we are

Igor G. Zurbenko; Amy L. Potrzeba

93

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

94

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

95

Tide operated power generating apparatus  

SciTech Connect

An improved tide operated power generating apparatus is disclosed in which a hollow float, rising and falling with the ocean tide, transmits energy to a power generator. The improvement comprises means for filling the float with water during the incoming tide to provide a substantial increase in the float dead weight during the outgoing tide. Means are further provided to then empty the float before the outgoing tide whereby the float becomes free to rise again on the next incoming tide.

Kertzman, H. Z.

1981-02-03

96

Watching the Weather in Real Time: Spitzer Light Curves of Variable L/T Transition Brown Dwarfs  

NASA Astrophysics Data System (ADS)

Recent observations of cool brown dwarfs in the time-domain have revealed large-amplitude variability at near-infrared wavelengths for a subset of objects spanning the transition between cloudy L-dwarf and clear T-dwarf spectral types. This quasi-periodic variability is indicative of patchy clouds and evolving weather patterns. Follow-up observations of 5 highly variable L/T transition brown dwarfs with Warm Spitzer are reported. Light curves spanning several consecutive rotations were obtained, with our longest observation of the highly variable T1.5 dwarf 2MASS 2139+02, spanning 48 hours. For all but one target, the dominant temporal component of the variability can be associated with rotation. Further changes in light curve shape are observed from rotation to rotation, demonstrating that cloud features evolve on timescales of hours. The amplitude, shape, and evolution timescales of the light curve place constraints on the dynamical regime of the atmosphere, including the nature of the cloud patchiness and whether the atmosphere is dominated by zonal jets or large-scale turbulence. In at least one case, light curves at [3.6] and [4.5] are not strongly correlated, indicating that different cloud and/or thermal structures reside at different atmospheric pressures.

Radigan, Jacqueline; Cowan, Nicolas B.; Showman, Adam P.; Apai, Daniel; Metchev, Stanimir A.; Marley, Mark S.; Artigau, Etienne; Burgasser, Adam J.; Jayawardhana, Ray; Goldman, Bertrand

2015-01-01

97

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

98

Relationship between variability of the semidiurnal tide in the Northern Hemisphere mesosphere and quasi-stationary planetary waves throughout the global middle atmosphere  

Microsoft Academic Search

To investigate possible couplings between planetary waves and the semidiurnal tide (SDT), this work examines the statistical correlations between the SDT amplitudes observed in the Northern Hemisphere (NH) mesosphere and stationary planetary wave (SPW) with wavenumber S=1 (SPW1) amplitudes throughout the global stratosphere and mesosphere. The latter are derived from the Aura-MLS temperature measurements. During NH summer-fall (July-October), the mesospheric

X. Xu; A. H. Manson; C. E. Meek; T. Chshyolkova; J. R. Drummond; C. M. Hall; Ch. Jacobi; D. Riggin; R. E. Hibbins; M. Tsutsumi; W. K. Hocking; W. E. Ward

2009-01-01

99

The large-scale spatio-temporal variability of precipitation over Sweden observed from the weather radar network  

NASA Astrophysics Data System (ADS)

Using measurements from the national network of 12 weather radar stations for the last decade (2000-2010), we investigate the large-scale spatio-temporal variability of precipitation over Sweden. These statistics provide useful information to evaluate regional climate models as well as for hydrology and energy applications. A strict quality control is applied to filter out noise and artifacts from the radar data. We focus on investigating four distinct aspects namely, the diurnal cycle of precipitation and its seasonality, the dominant time scale (diurnal vs. seasonal) of variability, precipitation response to different wind directions, and the correlation of precipitation events with the North Atlantic Oscillation (NAO) and the Arctic Oscillation (AO). When classified based on their intensity, moderate to high intensity events (precipitation > 0.34 mm (3 h)-1) peak distinctly during late afternoon over the majority of radar stations in summer and during late night or early morning in winter. Precipitation variability is highest over the southwestern parts of Sweden. It is shown that the high intensity events (precipitation > 1.7mm (3 h)-1) are positively correlated with NAO and AO (esp. over northern Sweden), while the low intensity events are negatively correlated (esp. over southeastern parts). It is further observed that southeasterly winds often lead to intense precipitation events over central and northern Sweden, while southwesterly winds contribute most to the total accumulated precipitation for all radar stations. Apart from its operational applications, the present study demonstrates the potential of the weather radar data set for studying climatic features of precipitation over Sweden.

Devasthale, A.; Norin, L.

2013-12-01

100

The large-scale spatio-temporal variability of precipitation over Sweden observed from the weather radar network  

NASA Astrophysics Data System (ADS)

Using measurements from the national network of 12 weather radar stations for the 11-year period 2000-2010, we investigate the large-scale spatio-temporal variability of precipitation over Sweden. These statistics provide useful information to evaluate regional climate models as well as for hydrology and energy applications. A strict quality control is applied to filter out noise and artifacts from the radar data. We focus on investigating four distinct aspects: the diurnal cycle of precipitation and its seasonality, the dominant timescale (diurnal versus seasonal) of variability, precipitation response to different wind directions, and the correlation of precipitation events with the North Atlantic Oscillation (NAO) and the Arctic Oscillation (AO). When classified based on their intensity, moderate- to high-intensity events (precipitation > 0.34 mm/3 h) peak distinctly during late afternoon over the majority of radar stations in summer and during late night or early morning in winter. Precipitation variability is highest over the southwestern parts of Sweden. It is shown that the high-intensity events (precipitation > 1.7 mm/3 h) are positively correlated with NAO and AO (esp. over northern Sweden), while the low intensity events are negatively correlated (esp. over southeastern parts). It is further observed that southeasterly winds often lead to intense precipitation events over central and northern Sweden, while southwesterly winds contribute most to the total accumulated precipitation for all radar stations. Apart from its operational applications, the present study demonstrates the potential of the weather radar data set for studying climatic features of precipitation over Sweden.

Devasthale, A.; Norin, L.

2014-06-01

101

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 on Red tides Time Topic Speaker Organization 8:50-9:10 Registration 9:10-9:20 Welcome 9:20-10:00 Forecasting the New England red tide : Current status, and ongoing efforts Don Anderson Woods Hole Oceanogr. i

Jeong, Hae Jin

102

Role of asymptomatic carriers and weather variables in persistent transmission of malaria in an endemic district of Assam, India  

PubMed Central

Background Malaria transmission is perennial in the Assam–Arunachal Pradesh interstate border areas in the Sonitpur district of Assam, India. A yearlong study was carried out on the incidence of symptomatic and asymptomatic malaria and the role of asymptomatic malaria carriers in persistent transmission of the disease. The relationships between malaria incidence and weather parameters were also investigated. Methods Active and mass blood surveys were conducted on a monthly basis in Bengenajuli, Sapairaumari Pathar, and Nigam villages near the Assam–Arunachal Pradesh border. Epidemiological indices were estimated for malaria-positive cases. Multiple linear regression between monthly malaria incidence and monthly average temperature, and relative humidity along with monthly total rainfall was carried out. The known malaria vectors collected in CDC light traps were identified and recorded. Results Slide positivity rate (SPR) and Plasmodium falciparum percent (Pf%) for symptomatic malaria were 26.1 and 79.8, respectively. Prevalence of malaria vectors was observed throughout the year with varying density. Anopheles philippinensis/nivipes and A. annularis were predominant among the seven known vector species recorded currently. Asymptomatic parasitemia was detected throughout the year with SPR ranging from 4.8 to 5.3. Monthly rainfall with 1-month lag had the highest correlation (r=0.92) with SPR. The relationship between SPR and weather factors was established as SPR=?114.22+0.58 T min+1.38 RH+0.03 RF (R 2=0.89; p=0.00). Conclusion Low and relatively constant levels of asymptomatic parasitemia was present in the study area. High malaria vector density and presence of asymptomatic malaria parasite carriers were responsible for persistent malaria transmission in the region. This study concludes that passive detection and prompt treatment of asymptomatic carriers is essential for preventing persistent disease transmission. Rainfall along with some other weather variables may be used for predicting the malaria epidemics in the region. The predictive information could be useful to target resources more effectively. PMID:25595688

Das, Nani Gopal; Dhiman, Sunil; Talukdar, Pranab Kumar; Goswami, Diganta; Rabha, Bipul; Baruah, Indra; Veer, Vijay

2015-01-01

103

Contribution of sand-associated enterococci to dry weather water quality.  

PubMed

Culturable enterococci and a suite of environmental variables were collected during a predominantly dry summer at a beach impacted by nonpoint source pollution. These data were used to evaluate sands as a source of enterococci to nearshore waters, and to assess the relationship between environmental factors and dry-weather enterococci abundance. Best-fit multiple linear regressions used environmental variables to explain more than half of the observed variation in enterococci in water and dry sands. Notably, during dry weather the abundance of enterococci in dry sands at the mean high-tide line was significantly positively related to sand moisture content (ranging from <1-4%), and the daily mean ENT in water could be predicted by a linear regression with turbidity alone. Temperature was also positively correlated with ENT abundance in this study, which may indicate an important role of seasonal warming in temperate regions. Inundation by spring tides was the primary rewetting mechanism that sustained culturable enterococci populations in high-tide sands. Tidal forcing modulated the abundance of enterococci in the water, as both turbidity and enterococci were elevated during ebb and flood tides. The probability of samples violating the single-sample maximum was significantly greater when collected during periods with increased tidal range: spring ebb and flood tides. Tidal forcing also affected groundwater mixing zones, mobilizing enterococci from sand to water. These data show that routine monitoring programs using discrete enterococci measurements may be biased by tides and other environmental factors, providing a flawed basis for beach closure decisions. PMID:25479559

Halliday, Elizabeth; Ralston, David K; Gast, Rebecca J

2015-01-01

104

Diagnostic Studies of Mesoscale Variability in the Florida Current at the Downstream Boundary of the Intra-Americas Sea (IAS)  

Microsoft Academic Search

Most of the throughflow of the Intra-Americas Sea (IAS) passes through the Straits of Florida as the Florida Current. The Florida Current forms an intense jet and frontal system along the shelfbreak of the East Florida Shelf. It exhibits extrinsic variability associated with tides, synoptic weather systems, and seasonal and longer- term variations of atmospheric forcing and oceanic general circulation.

C. N. Mooers; I. Bang

2007-01-01

105

Dynamics of ocean tides  

SciTech Connect

Ocean tide information can solve vital problems in oceanology and geophysics. Elastic properties of the Earth's crust, tidal gravity variations and deviations in trajectories of artificial satellites can be studied from the dynamics of ocean tides. This book contains mathematical models and applications on several problems related to ocean tide dynamics. The first part serves as an introduction to studies of tidal dynamics equations and the application in experimental studies. Specific problems like free oscillations and forced tidal oscillations in the oceans and the ocean-shelf system are discussed. The book deals with tidal flow in the bottom boundary layer. Data and models are presented and experimental and theoretical results are compared.

Maarchuk, G.I.; Kagan, B.A. (P.P. Shirshov Inst. of Oceanology, Moscow (SU))

1989-01-01

106

Invited paper Tide distribution and  

E-print Network

Invited paper Tide distribution and tapping into tidal energy OCEANOLOGIA, 46 (3), 2004. pp. 291­331. C 2004, by Institute of Oceanology PAS. KEYWORDS Tides Extreme tides Energy conservation Tidal power uses have their roots in the small tide mills constructed along tidal shores. In a tidal mill, a small

Kowalik, Zygmunt

107

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

108

Students' Understanding of Tides.  

ERIC Educational Resources Information Center

Reports the findings of research into students' understanding of tides. Students from secondary school and pre-service primary school teacher trainees were chosen as subjects and their understanding was assessed by questionnaire. (Author/CCM)

Viiri, Jouni

2000-01-01

109

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

110

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

111

The Role of Gravity Waves in Modulating Atmospheric Tides  

NASA Technical Reports Server (NTRS)

We discuss results for the diurnal and semidiurnal tides obtained from our 3-D, time dependent numerical spectral model (NMS), extending from the ground up into the thermosphere, which incorporates Hines' Doppler spread parameterization of small scale gravity waves (GW). In the DSP, GW momentum (and energy) are conserved as the waves modulate the background flow and are filtered by the flow.As a consequence, the GW interaction tightly couples the dynamic components of the middle atmosphere with strong non-linear interactions between mean zonal circulation, tides and planetary waves to produce complicated patterns of variability much like those observed. The major conclusions are: (1) Since GW momentum is deposited in the altitude regime of increasing winds, the amplitude of the diurnal tide is amplified and its vertical wavelength is reduced at altitudes between 80 and 120 km. Wave filtering by the mean zonal circulation (with peak velocities during solstice) causes the GW flux to peak during equinox, and this produces a large semi-annual variation in the tide that has been observed on UARS. (2) Without the diurnal tide, the semidiurnal tide would also be modulated in this way. But the diurnal tide filters out the GW preferentially during equinox, so that the semidiurnal tide, at higher altitudes, tends to peak during solstice. (3) Under the influence of GW, the tides are modulated also significantly by planetary waves, with periods between 2 and 30 days, which are generated preferentially during solstice in part due to baroclinic instability.

Mayr, H. G.; Mengel, J. G; Chan, K. L.; Porter, H. S.

1999-01-01

112

Longitudinal variation of tides in the MLT region: 2. Relative effects of solar radiative and latent heating  

E-print Network

Click Here for Full Article Longitudinal variation of tides in the MLT region: 2. Relative effects for vertically propagating tides that impose longitude variability on mesospherelower thermosphere (MLT) winds is more important than latent heating in accounting for MLT longitude variability due to tides although

Forbes, Jeffrey

113

Role of lunar atmospheric tides in thermosphere density  

NASA Astrophysics Data System (ADS)

Half a million objects, including debris, satellites, and the International Space Station, orbit Earth in the thermosphere, the largest layer of the planet's atmosphere. To predict the orbits—and potential collisions—of all this stuff, scientists must forecast the weather in the thermosphere. To help develop a more comprehensive and nuanced model of this weather, Zhang et al. explored the role that lunar atmospheric tides play in the density of thermosphere air.

Palus, Shannon

2014-11-01

114

A Study of the Relationship between Weather Variables and Electric Power Demand inside a Smart Grid/Smart World Framework  

PubMed Central

One of the main challenges of today's society is the need to fulfill at the same time the two sides of the dichotomy between the growing energy demand and the need to look after the environment. Smart Grids are one of the answers: intelligent energy grids which retrieve data about the environment through extensive sensor networks and react accordingly to optimize resource consumption. In order to do this, the Smart Grids need to understand the existing relationship between energy demand and a set of relevant climatic variables. All smart “systems” (buildings, cities, homes, consumers, etc.) have the potential to employ their intelligence for self-adaptation to climate conditions. After introducing the Smart World, a global framework for the collaboration of these smart systems, this paper presents the relationship found at experimental level between a range of relevant weather variables and electric power demand patterns, presenting a case study using an agent-based system, and emphasizing the need to consider this relationship in certain Smart World (and specifically Smart Grid and microgrid) applications.

Hernández, Luis; Baladrón, Carlos; Aguiar, Javier M.; Calavia, Lorena; Carro, Belén; Sánchez-Esguevillas, Antonio; Cook, Diane J.; Chinarro, David; Gómez, Jorge

2012-01-01

115

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

116

Weather Variability Influences Color and Phenolic Content of Pigmented Baby Leaf Lettuces throughout the Season.  

PubMed

The lack of consistency in homogeneous color throughout the season of pigmented baby leaf lettuce is a problem for growers because of the rejection of the product and consequently the economic loss. Changes in color as well as individual and total phenolic composition and content as a response to the climatic variables were studied following the analysis of three pigmented baby leaf lettuces over 16 consecutive weeks from February to May, which corresponded to the most important production season in winter in Europe. Color and phenolic content were significantly (P ? 0.001) affected by cultivar, harvest week, and climatic variables that occurred in the last week before harvest. Radiation and temperature showed positive correlations with the content of phenolic acids and flavonoids that increased in all three cultivars as the season progressed. Cyanidin-3-O-(6''-O-malonyl)-glucoside content showed positive correlations with temperature and radiation but only in Batavia cultivars whereas in red oak leaf the correlation was with cold temperatures. Regarding hue angle, a positive correlation was shown with the number of hours at temperatures lower than 7 °C. A relationship between hue angle and the content of anthocyanins was not possible to establish. These results suggest that the colorimetric measurement of color cannot be used as a good indicator of anthocyanin accumulation because other pigments such as chlorophylls and carotenoids may contribute as well to the leaf color of pigmented lettuce. This study provides information about the impact of genotype and environment interactions on the biosynthesis of phenolic compounds to explain the variability in the leaf color and product appearance. PMID:25650715

Marin, Alicia; Ferreres, Federico; Barberá, Gonzalo G; Gil, María I

2015-02-18

117

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

118

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.

119

Characteristics that Help Households Weather Climate Variability, Now and in the Future  

NASA Astrophysics Data System (ADS)

A number of characteristics of rural livelihood management are directly related to improving resilience against the impacts of seasonal variability in climate, such as diversification of crops or income strategies. However, traditional strategies that confer resilience to the household may be difficult to sustain in the modern era. Additionally, the frequency and distribution of extreme rainfall events or seasons may change as the composition of the atmosphere is altered. In order to reverse a potential negative trend in the ability of developing country households to handle climate shocks, we suggest that three key components of the system will need to be strengthened. The first is baseline resilience, which we suggest is primarily a function of a) diversification of income opportunities, and b) storage capacity for consumption smoothing (water reservoirs, soil moisture holding capacity, mechanisms for saving wealth from season to season such as granaries, animals, or bank accounts). The second is access to, and ability to effectively utilize, new information. The third is a supportive economic and policy environment such as access to crop insurance, functional markets, credit. By improving climate information systems and building skills to comprehend and utilize climate information in decision-making, adjustments at the seasonal time scale will add to the ability to withstand climate shocks and take advantage of opportunities. The combination of baseline resilience and ability to respond to new information will contribute substantially to rural households' ability to adapt to changing climate conditions in the next century. Experiences from East and Southern Africa will be used to illustrate these points.

Phillips, J. G.; Seth, A.

2002-05-01

120

Ocean Tide Loading Computation  

NASA Technical Reports Server (NTRS)

September 15,2003 through May 15,2005 This grant funds the maintenance, updating, and distribution of programs for computing ocean tide loading, to enable the corrections for such loading to be more widely applied in space- geodetic and gravity measurements. These programs, developed under funding from the CDP and DOSE programs, incorporate the most recent global tidal models developed from Topex/Poscidon data, and also local tide models for regions around North America; the design of the algorithm and software makes it straightforward to combine local and global models.

Agnew, Duncan Carr

2005-01-01

121

Florida Red Tide Current Status  

NSDL National Science Digital Library

This Fish and Wildlife Research Institute website provides links to several Florida-based red tide sites. These sites include the current status of Florida's red tide, a photo gallery of red tide distribution maps, and regional Florida red tide statuses. The site expands further on its research and contains information on the Florida manatee, Florida panther, freshwater, geographic information systems/mapping, habitat, saltwater and wildlife. This is a nice resource for a broad overview of Florida ecosystems and natural resources.

122

Tsunami-tide interactions: A Cook Inlet case study  

NASA Astrophysics Data System (ADS)

First, we investigated some aspects of tsunami-tide interactions based on idealized numerical experiments. Theoretically, by changing total ocean depth, tidal elevations influence the speed and magnitude of tsunami waves in shallow regions with dominating tidal signals. We tested this assumption by employing a simple 1-D model that describes propagation of tidal waves in a channel with gradually increasing depth and the interaction of the tidal waves with tsunamis generated at the channel's open boundary. Important conclusions from these studies are that computed elevations by simulating the tsunami and the tide together differ significantly from linear superposing of the sea surface heights obtained when simulating the tide and the tsunami separately, and that maximum tsunami-tide interaction depends on tidal amplitude and phase. The major cause of this tsunami-tide interaction is tidally induced ocean depth that changes the conditions of tsunami propagation, amplification, and dissipation. Interactions occur by means of momentum advection, bottom friction, and variable water flux due to changing total depth and velocity. We found the major cause of tsunami-tide interactions to be changing depth. Secondly, we investigate tsunami-tide interactions in Cook Inlet, Alaska, employing a high-resolution 2-D numerical model. Cook Inlet has high tides and a history of strong tsunamis and is a potential candidate for tsunami impacts in the future. In agreement with previous findings, we find that the impacts of tsunamis depend on basin bathymetries and coastline configurations, and they can, in particular, depend on tsunami-tide interactions. In regions with strong tides and tsunamis, these interactions can result in either intensification or damping of cumulative tsunami and tide impacts, depending on mean basin depth, which is regulated by tides. Thus, it is not possible to predict the effect of tsunami-tide interaction in regions with strong tides without making preliminary investigations of the area. One approach to reduce uncertainties in tsunami impact in regions with high tides is to simulate tsunamis together with tidal forcing.

Kowalik, Zygmunt; Proshutinsky, Andrey

2010-04-01

123

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

124

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

125

Tides in Titan  

NASA Technical Reports Server (NTRS)

Tides raised in Titan by Saturn give rise to a static and a periodic deformation; both will be measured with Doppler tracking during the CASSINI Tour of the Saturnian System. The latter deformation is due to the significant eccentricity of Titan's orbit and has a frequency equal to the orbital angular velocity of Titan.

Rappaport, Nicole J.

1997-01-01

126

Ocean tide energy converter  

SciTech Connect

A tide motor energy source includes a tidal piston with a valved chamber. The piston drives a hydraulic ram to generate electrical power through a pressure accumulator and hydraulic motor. The ram can be locked hydraulically to enable the tidal piston to be held fixed at a desired elevation and the valves in the chamber permit it to be filled with water or air. The piston with its chamber filled with air at its low tide position and then released for controlled ascent while submerged acts as a submerged float for driving the ram upwardly while the tide runs in during one phase of its operation. The piston with its chamber filled with water while locked at its highest position as the tide begins to run out, and then released to fall under control, acts as a weight suspended in air after the water level drops below the piston for driving the ram downwardly during the second phase of its operation. The rising and falling motion of the tidal piston is used as the energy source.

Rainey, D.E.

1980-06-24

127

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.

Elenor Ely

128

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.

129

Is coastal mean sea level rising faster than the global mean? A comparison between tide gauges and satellite altimetry  

E-print Network

Is coastal mean sea level rising faster than the global mean? A comparison between tide gauges 2008; accepted 9 January 2009; published 6 March 2009. [1] Based on a careful selection of tide gauges. Although trends agree well, tide gauges-based mean sea level exhibits much larger interannual variability

Paris-Sud XI, Université de

130

A statistical–dynamical scheme for reconstructing ocean forcing in the Atlantic. Part I: weather regimes as predictors for ocean surface variables  

Microsoft Academic Search

The links between the observed variability of the surface ocean variables estimated from reanalysis and the overlying atmosphere\\u000a decomposed in classes of large-scale atmospheric circulation via clustering are investigated over the Atlantic from 1958 to\\u000a 2002. Daily 500 hPa geopotential height and 1,000 hPa wind anomaly maps are classified following a weather-typing approach\\u000a to describe the North Atlantic and tropical Atlantic atmospheric

Christophe Cassou; Marie Minvielle; Laurent Terray; Claire Périgaud

2011-01-01

131

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

132

Red Tide Activities  

NSDL National Science Digital Library

This University of South Florida web site contains links to the article "Tiny Toxic Terrors: Harmful Algal Blooms" and four computer-based activities that teach students about various aspects of red tide. Activities include: "Where could they be?," "Is it a plant or animal cell?," "What is bioluminescence?," and "How does plankton shape affect plankton movement?" Each activity contains hyperlinks to pertinent materials, maps, and information to complete the activity.

Making Waves

133

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

134

Longitudinal variation of tides in the MLT region: 1. Tides driven by tropospheric net radiative heating  

E-print Network

Click Here for Full Article Longitudinal variation of tides in the MLT region: 1. Tides driven to estimate the corresponding MLT tides is the GlobalScale Wave Model (GSWM). The radiative flux products are 20 ± 5 K for the diurnal tide and 6 ± 2 K for the semidiurnal tide. The computed tides

Forbes, Jeffrey

135

Population dynamics of red tide dinoflagellates  

NASA Astrophysics Data System (ADS)

Sea-surface discolorations due to high concentrations of phytoplankton are called red tides. Their ecological significance is a long standing puzzle, and they are sometimes considered pathological. Here we propose that many red tides, particularly but not exclusively those composed of certain autotrophic dinoflagellates, are presexual/sexual swarms, essential links in their complex life cycles. This view provides a rationale for the appearance of these organisms in thin surface layers, and helps explain their ephemeral nature. We suggest that further understanding of this phenomenon, and of phytoplankton ecology in general, would benefit from attention to the 'net reproductive value? (r) over the whole life cycle as well as to the division rate (?) of the vegetative phase. It is argued that r is strategically adapted to seasonal cycles and long term environmental variability, while ? reflects tactical needs (timing) and constraints (grazers, parasites) on vegetative growth.

Wyatt, Timothy; Zingone, Adriana

2014-03-01

136

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

137

8.F Tides  

NSDL National Science Digital Library

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: The figure below gives the depth of the water at Montauk Point, New York, for a day in November. How many high tides took place on this day? How many l...

138

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

139

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...

140

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

141

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

142

Lunar tide in the thermosphere and weakening of the northern polar vortex  

NASA Astrophysics Data System (ADS)

The lunar tide and its variability are beginning to be realized as elements of ionosphere-thermosphere weather. Herein we demonstrate that an enhancement in M2 amplitude at 110 km in the dynamo region is related to the timing and intensity of stratospheric polar vortex weakening (PVW). Timing of the PVW, which typically occurs during January-February, changes on the order of 4-7 d/yr between 2002 and 2013 and the M2 enhancement changes with it, with a time delay of order 2.8 days. The M2 temperature amplitude at 110 km as determined from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) measurements on the Thermosphere Ionosphere Mesosphere Energetics Dynamics (TIMED) spacecraft increases linearly from about 20 K to 29 K as the westward zonal mean zonal wind increases from about 10 m s-1 to 80 m s-1 at 70°N and 48 km altitude in accord with PVW events from year to year according to Modern-Era Retrospective Analysis for Research and Applications (MERRA) data. These relationships point to a level of predictability regarding impacts of the lunar tide on thermosphere and ionosphere densities, winds, and plasma drifts.

Zhang, Xiaoli; Forbes, Jeffrey M.

2014-12-01

143

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

144

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

145

Formulation of a variable-function three-dimensional model, with applications to the M 2 and M 4 tide on the North-West European Continental Shelf  

NASA Astrophysics Data System (ADS)

The major steps in the mathematical formulation of a three-dimensional (3D) tidal model using a variable modal approach to represent current profiles in the vertical are presented in the initial section of this paper. Using this method the number of functions through the vertical can be increased locally where enhanced resolution is required, while ensuring mass and momentum conservation, and reducing computational time using a time-splitting technique. Calculations of the M 2 and M 4 tidal elevations and currents on the North-West European Continental Shelf are performed, initially with bed stress determined from the depth mean current, a hybrid 2D-3D model, the advantages of which are discussed in the paper, and subsequently computing the bed stress from the bottom current (a full 3D model). Computations are made using a range of viscosity formulations and bed-friction coefficients. A rigorous comparison of computed currents against the harmonic analysis of observations from 278 measured time-series is performed in order to determine the accuracy of the computed currents, which were found to agree to within ± 5 cm s -1 with observations at over 200 locations.

Davies, Alan M.; Kwong, Simon C. M.; Flather, Roger A.

1997-02-01

146

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

147

Lunar Core and Tides  

NASA Technical Reports Server (NTRS)

Variations in rotation and orientation of the Moon are sensitive to solid-body tidal dissipation, dissipation due to relative motion at the fluid-core/solid-mantle boundary, and tidal Love number k2 [1,2]. There is weaker sensitivity to flattening of the core-mantle boundary (CMB) [2,3,4] and fluid core moment of inertia [1]. Accurate Lunar Laser Ranging (LLR) measurements of the distance from observatories on the Earth to four retroreflector arrays on the Moon are sensitive to lunar rotation and orientation variations and tidal displacements. Past solutions using the LLR data have given results for dissipation due to solid-body tides and fluid core [1] plus Love number [1-5]. Detection of CMB flattening, which in the past has been marginal but improving [3,4,5], now seems significant. Direct detection of the core moment has not yet been achieved.

Williams, J. G.; Boggs, D. H.; Ratcliff, J. T.

2004-01-01

148

Weather Forecasting  

NSDL National Science Digital Library

Students consider how weather forecasting plays an important part in their daily lives. They learn about the history of weather forecasting — from old weather proverbs to modern forecasting equipment — and how improvements in weather technology have saved lives by providing advance warning of natural hazards.

Integrated Teaching and Learning Program,

149

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.

150

Winter 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. Weather affects our everyday lives. Some days it's sunny and some days its not. The years weather is split up into seasons. 1. What are the four seasons? 2. What kind of weather do you see in the summer? 3. What kind of weather is unique to winter? 4. ...

Mrs. Bellows

2009-09-28

151

Tides in the Weddell Sea Robertson et al., 1998 TIDES IN THE WEDDELL SEA  

E-print Network

Tides in the Weddell Sea Robertson et al., 1998 TIDES IN THE WEDDELL SEA Robin Robertson, Laurie of baroclinic tides. Model results indicate that tides play a significant role in the circulation and heat flux in the Weddell Sea. We discuss the influence of tides on mean flow through the modified effective bot- tom drag

Robertson, Robin

152

M2 world ocean tide from tide gauge measurements  

SciTech Connect

An empirical model of the M2 oceanic tide has been computed form 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. (CNES/CNRS, Toulouse (France))

1991-06-01

153

Solutions to Avoid Red Tide, Inc.  

NSDL National Science Digital Library

This "Solutions to Avoid Red Tide" (START) webpage offers basic information and videos about red tide, effects of red tide, and research being done regarding red tide. START is a grassroots, non-profit organization based in Florida. Their mission is to keep federal, state, and local officials aware of red tide and to get these officials to fund projects to remediate and/or prevent the problem. Information on how to join or help START is also provided.

Solutions to Avoid Red Tide, Inc.

154

Solar heating using the tide  

SciTech Connect

A fixed tank is disposed in the sea adjacent a floating solar still, with a flexible conduit extending between a lower portion of the tank and the interior of the still. A one-way check valve disposed in the lower portion of the tank permits sea water to enter the tank and fill it as the tide rises. As the tide lowers, water flows from the tank through a restriction in the conduit to the solar still.

Cardinal, D.E.

1980-04-08

155

Obliquity Tides on Hot Jupiters  

E-print Network

Obliquity tides are a potentially important source of heat for extrasolar planets on close-in orbits. Although tidal dissipation will usually reduce the obliquity to zero, a nonzero obliquity can persist if the planet is in a Cassini state, a resonance between spin precession and orbital precession. Obliquity tides might be the cause of the anomalously large size of the transiting planet HD 209458b.

Joshua N. Winn; Matthew J. Holman

2005-06-20

156

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

157

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.

158

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

159

Numerical simulations of the internal tide in a submarine canyon  

NASA Astrophysics Data System (ADS)

Three-dimensional numerical simulations of the generation and propagation of the semidiurnal internal tide in a submarine canyon with dimensions similar to those of the Monterey Canyon are carried out using a primitive equation model. Forcing with just sea level at the offshore boundary in an initially horizontally homogeneous ocean with realistic vertical stratification, internal tides are generated at the canyon foot and rim, and along portions of the canyon floor. The results compare favorably with observations, both indicating enhancement of energy along the canyon floor propagating at an angle consistent with linear internal wave theory. Due to the earth's rotation, internal tide energy is distributed asymmetrically in the cross-canyon direction, favoring the southern side. The effect of canyon floor slope is explored, with the finding that small changes in the slope result in large changes in the amount and distribution of the internal tide energy. Canyons whose floors are subcritical with respect to the semidiurnal frequency along their entire length have very little baroclinic energy, whereas canyons that are near-critical along much of their length, such as the Monterey Canyon, develop strong internal tides that propagate shoreward. Canyons that are near-critical at their mouths but supercritical further inshore generate the most internal tidal energy overall, although little of it makes it onto the continental shelf shoreward of the canyon head. The effects of internal tides within the canyons can be seen outside the canyons as well. Water is transported from depth onto the adjacent continental shelf along the canyon rims. This tidal pumping can be responsible for alongshore internal tide propagation and tidal-period surface currents with relatively small horizontal scales of variability.

Petruncio, Emil T.; Paduan, Jeffrey D.; Rosenfeld, Leslie K.

2002-06-01

160

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.

161

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

162

Winter Weather  

MedlinePLUS

... About CDC.gov . Natural Disasters and Severe Weather Earthquakes Being Prepared Emergency Supplies Home Hazards Indoor Safety ... What's New A - Z Index Disasters & Severe Weather Earthquakes Extreme Heat Floods Hurricanes Landslides Tornadoes Tsunamis Volcanoes ...

163

Weather Odds  

NSDL National Science Digital Library

The Weather Odds site helps users learn about the odds of various weather happening at monthly and daily levels. The site relies on past climate data from thousands of locations and it's a fine resource. In the Quick Weather Data area, visitors can check out popular United States locations or use the search engine to breeze along to their preferred habitat. This version of Weather Odds is compatible with all operating systems.

2014-05-08

164

Evaluating effects of climate variability, extreme weather events and thinning on carbon and water exchanges in managed temperate forests in eastern Canada  

NASA Astrophysics Data System (ADS)

In this study the impact of climate variability and extreme weather events on gross ecosystem productivity (GEP), ecosystem respiration (RE), net ecosystem productivity (NEP) and evapotranspiration (E) is evaluated in an age-sequence (74-, 39- and 11-years old) of temperate pine (Pinus strobus L.) forests, north of Lake Erie in southern Ontario, Canada using ten years (2003-2012) of eddy covariance flux and meteorological data. Fluxes from conifer stands are also compared with measurements made in an 80-year-old deciduous (Carolinian) forest, established in 2012. All four sites are managed forests and part of the Turkey Point Flux Station and global Fluxnet. Ten-year mean NEP values were 169 (75 to 312), 371 (305 to 456, over 2008-2012) and 141 (-10 to 420) g C/m2/year in the 74-, 39-, and 11-year-old stand, respectively, while mean NEP in the 80-year-old deciduous stand was 286 g C/m2/year in 2012. This region is affected by low frequency climate oscillations, such as El Niño-Southern Oscillation (ENSO) and the North Atlantic Oscillation (NAO). The study period experienced four distinct extreme weather patterns: warm and dry springs in 2005 and 2012, extremely wet and warm summer in 2006, a summer drought in 2007 and warm summers in 2010 and 2012. In February-March 2012, the 74-year-old stand was selectively thinned and approximately 30% of trees were removed to improve light and water availability and stimulate growth of remaining trees. Thinning and warm/dry spring reduced NEP in the first post-thinning year, with mean annual NEP of 75 g C/m2/year in 2012. Increased supply of dead organic matter and warm temperatures in 2012 increased RE much more than GEP, resulting in lower annual NEP. Heat stress and drought in spring of 2005 reduced NEP of the 74-year stand to 78 g C/m2/year. The impact of this extreme weather event on NEP was similar to that observed in 2012 when stand experienced a drastic structural change, dry spring and warm temperatures throughout the growing season. Results of this study indicate that the carbon cycle of forests in Great Lakes region in eastern North America is more affected by changes in temperature rather than variations in precipitation, unless dry conditions coincide with the short and intense early growing season of the region. This research helps to assess the vulnerability of managed forests to future climate change and extreme weather events.

Arain, M.; Brodeur, J. J.; Trant, J.; Thorne, R.; Peichl, M.; Kula, M.; Parsaud, A.; Khader, R.

2013-12-01

165

Rates of Chemical Weathering  

NSDL National Science Digital Library

In this activity, students will investigate the weathering of rocks by chemical processes. They will use effervescent cleansing tablets as a model for rock, and vary surface area, temperature, and acidity to see how rapidly the "rock" dissolves. This investigation will help them understand three of the factors that affect the rate of chemical weathering and develop better understanding of how to design controlled experiments by exploring only one experimental variable at a time.

Passow, Michael

166

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

167

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

168

World Weather  

NSDL National Science Digital Library

What's going on in the world of weather? Are there storms around Sri Lanka? What about the snows of Kilimanjaro? These can be pressing questions, indeed, and the World Weather app is a great way to stay in touch with weather patterns around the globe. Users will find that they can just type in a city name to see the current weather and also zoom around the globe as they see fit. It's a remarkable addition to the world of existing weather tracking apps and is compatible with all operating systems.

Elias, Jaume S.

2014-02-20

169

ISPOL weather conditions in the context of long-term climate variability in the north-western Weddell Sea  

Microsoft Academic Search

At the transition from austral spring to summer of 2004\\/2005, the field experiment Ice Station Polarstern (ISPOL) took place in the north-western Weddell Sea to observe physical and biological atmosphere–sea ice–ocean processes. The objective of this paper is to discuss the meteorological conditions during ISPOL in the context of long-term climate variability mainly in the north-western Weddell Sea region. This

Jörg Bareiss; Klaus Görgen

2008-01-01

170

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

171

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.

172

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

E-print Network

Trapped diurnal internal tides, propagating semidiurnal internal tides, and mixing estimates profiles. Elevated diffusivity estimates and energetic diurnal (D1) and semidiurnal (D2) internal tides and associated with internal tides is not novel, the combination of resolution and extent in this ongoing data

Johnston, Shaun

173

ACOUSTICAL EFFECTS OF INTERNAL TIDES ACOUSTICAL EFFECTS OF INTERNAL TIDES ON SHALLOW WATER  

E-print Network

ACOUSTICAL EFFECTS OF INTERNAL TIDES ACOUSTICAL EFFECTS OF INTERNAL TIDES ON SHALLOW WATER tides on the acoustic propagation. A towed broadband acoustic source and a 4-hydro- phone vertical array of the environment, including bottom influence, source range and depth and internal tides effects, can be clearly

Jesus, Sérgio M.

174

The Tides Of Time Issue 29  

E-print Network

The Tides of Time 29 • 1 • Easter Vacation 2004 The Oxford University Doctor Who Society Magazine The Tides of Time Easter Vacation 2004 Issue 29 BUFFY AND THE BRITISH Star Trek The Prisoner The career of Brian Clemens … …and... something called Doctor Who, apparently. The Tides of Time 29 • 2 • Easter Vacation 2004 The Tides of Time II ssue 29 Easter Vacatiion 2004 Editor Matthew Kilburn matthew.kilburn@history.oxford.ac.uk Sub-Editor Alexandra Cameron...

2010-01-01

175

Variable Strength of Forest Stand Attributes and Weather Conditions on the Questing Activity of Ixodes ricinus Ticks over Years in Managed Forests  

PubMed Central

Given the ever-increasing human impact through land use and climate change on the environment, we crucially need to achieve a better understanding of those factors that influence the questing activity of ixodid ticks, a major disease-transmitting vector in temperate forests. We investigated variation in the relative questing nymph densities of Ixodes ricinus in differently managed forest types for three years (2008–2010) in SW Germany by drag sampling. We used a hierarchical Bayesian modeling approach to examine the relative effects of habitat and weather and to consider possible nested structures of habitat and climate forces. The questing activity of nymphs was considerably larger in young forest successional stages of thicket compared with pole wood and timber stages. Questing nymph density increased markedly with milder winter temperatures. Generally, the relative strength of the various environmental forces on questing nymph density differed across years. In particular, winter temperature had a negative effect on tick activity across sites in 2008 in contrast to the overall effect of temperature across years. Our results suggest that forest management practices have important impacts on questing nymph density. Variable weather conditions, however, might override the effects of forest management practices on the fluctuations and dynamics of tick populations and activity over years, in particular, the preceding winter temperatures. Therefore, robust predictions and the detection of possible interactions and nested structures of habitat and climate forces can only be quantified through the collection of long-term data. Such data are particularly important with regard to future scenarios of forest management and climate warming. PMID:23372852

Lauterbach, Ralf; Wells, Konstans; O'Hara, Robert B.; Renner, Swen C.

2013-01-01

176

The tide in the seas of Titan  

Microsoft Academic Search

The parameters of the tides in the near-global ocean that may exist on Titan are assessed. A formula for the difference between the maximum heights of the oceanic and body tides is used to determine that the amplitude of the apparent, near-stationary, oceanic tide on Titan is greater than about 100 m. The effects of tidal dissipation are evaluated, showing

Carl Sagan; S. F. Dermott

1982-01-01

177

COUNTS OF RED TIDE ORGANISMS Gymnodinium breve  

E-print Network

COUNTS OF RED TIDE ORGANISMS Gymnodinium breve AND ASSOCIATED OCEANOGRAPHIC DATA FROM FLORIDA WEST, Fred A. Seaton, Secretary Fish and Wildlife Service, Arnie J. Suoraela, Commissioner COUNTS OF RED TIDE of red tide organisms, Gymnodinium breve, and associated oceanographic data from Florida west coast, 1954

178

NOAA New England Red Tide Information Center  

NSDL National Science Digital Library

This NOAA website offers a brief explanation of red tide and a large bloom that spread from the Gulf of Maine to the Massachusetts Bay in 2005. The site explains NOAA's efforts to remediate red tide in New England as well as prevent new occurrences. The site features hyperlinks to research funding, legislation, and other NOAA sites that feature red tide.

179

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

180

Tide and Current Glossary Silver Spring, MD  

E-print Network

Tide and Current Glossary Silver Spring, MD January 2000 U.S. DEPARTMENT OF COMMERCE National Products and Services #12;Tide and Current Glossary U.S. DEPARTMENT OF COMMERCE Norman Mineta, Secretary Printing History of Tide and Current Glossary Special Publication No. 228, Coast and Geodetic Survey

181

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. ...

182

Waste glass weathering  

SciTech Connect

The weathering of glass is reviewed by examining processes that affect the reaction of commercial, historical, natural, and nuclear waste glass under conditions of contact with humid air and slowly dripping water, which may lead to immersion in nearly static solution. Radionuclide release data from weathered glass under conditions that may exist in an unsaturated environment are presented and compared to release under standard leaching conditions. While the comparison between the release under weathering and leaching conditions is not exact, due to variability of reaction in humid air, evidence is presented of radionuclide release under a variety of conditions. These results suggest that both the amount and form of radionuclide release can be affected by the weathering of glass.

Bates, J.K.; Buck, E.C.

1993-12-31

183

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

184

Weather Watch  

NSDL National Science Digital Library

The weather watch activity is designed to provide instruction on how to collect weather data from on-line databases. Following completion of this activity the user will be able to look up weather conditions for any city in North America, know what radar maps are used for and how to access them, and know how to access satellite images and make estimated guesses on cloud conditions for their area from them.

Hopson, R.

185

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.

186

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

187

tides 8/16/2007 1 2.3 Fitting the tide  

E-print Network

tides 8/16/2007 1 2.3 Fitting the tide Find a vertical pier at the edge of the sea, put a scale tides, a resonance effect caused by the funneling shape of the basin. As you can see from the graph, the amplitude of these tides is almost 6 meters whereas on the ocean, tides are a third or a quarter of that

Taylor, Peter

188

WWW Tide and Current Predictor  

NSDL National Science Digital Library

This web page is a tide and current predictor provided by Dean Pentcheff from the University of South Carolina. The site allows you to select a region, choose the location, and then prepare a customized table of tidal height and/or current speed and direction.

Dean Pentcheff

189

The magnetic tides of Honolulu  

USGS Publications Warehouse

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, Jeffrey J.; Rigler, Erin Joshua

2013-01-01

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

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.

2012-06-26

192

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.

193

Multiyear Climate Variability and Dengue—El Niño Southern Oscillation, Weather, and Dengue Incidence in Puerto Rico, Mexico, and Thailand: A Longitudinal Data Analysis  

PubMed Central

Background The mosquito-borne dengue viruses are a major public health problem throughout the tropical and subtropical regions of the world. Changes in temperature and precipitation have well-defined roles in the transmission cycle and may thus play a role in changing incidence levels. The El Niño Southern Oscillation (ENSO) is a multiyear climate driver of local temperature and precipitation worldwide. Previous studies have reported varying degrees of association between ENSO and dengue incidence. Methods and Findings We analyzed the relationship between ENSO, local weather, and dengue incidence in Puerto Rico, Mexico, and Thailand using wavelet analysis to identify time- and frequency-specific association. In Puerto Rico, ENSO was transiently associated with temperature and dengue incidence on multiyear scales. However, only local precipitation and not temperature was associated with dengue on multiyear scales. In Thailand, ENSO was associated with both temperature and precipitation. Although precipitation was associated with dengue incidence, the association was nonstationary and likely spurious. In Mexico, no association between any of the variables was observed on the multiyear scale. Conclusions The evidence for a relationship between ENSO, climate, and dengue incidence presented here is weak. While multiyear climate variability may play a role in endemic interannual dengue dynamics, we did not find evidence of a strong, consistent relationship in any of the study areas. The role of ENSO may be obscured by local climate heterogeneity, insufficient data, randomly coincident outbreaks, and other, potentially stronger, intrinsic factors regulating transmission dynamics. Please see later in the article for the Editors' Summary PMID:19918363

Johansson, Michael A.; Cummings, Derek A. T.; Glass, Gregory E.

2009-01-01

194

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

195

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

196

Fracture characteristics in weathered granites  

NASA Astrophysics Data System (ADS)

The variability of weathered materials is an important factor in the geotechnical characterization of rock for engineering purposes. Most engineering rock mass classifications include weathering schemes that separate the weathering profile into zones or grades that depend upon the engineering and geological properties of the rock. Many geotechnical characteristics, including weathering, are controlled by the density and arrangement of fractures within the rock, but the relationships between fracture patterns and weathering grades are typically not addressed. Fracture characteristics were investigated in 13 exposures in five study areas in weathered granite in eastern Asia. All weathering grades were present, but never in the same exposure. Two approaches were used to evaluate the field data: (1) joint spacings were tabulated and examined within each weathering grade (tabulated classification); and (2) each exposure was classified according to the dominant weathering grade (visual classification). Mean and median joint spacings and joint spacing frequency distributions were analyzed and compared statistically for each approach. The box fractal dimensions for joint spacing were calculated for exposures classified visually in each weathering grade. Three-dimensional models of fresh and weathered granite were also generated and sampled for comparison to the field data. Mean joint spacing is usually 25% or more closer in weathered granite than it is in fresh granite, and the difference between the mean spacings for weathered granite and fresh granite tend to be statistically significant. There are no significant differences between any distribution medians. The joint spacing distributions for weathered granite and fresh granite are also not statistically significantly different, and there are no significant differences among the joint spacing frequency distributions for the different grades of weathered granite. Fractal analysis of joint spacings, however, suggests spacing characteristics of fresh and slightly weathered (SW) granite are very different from those in moderately, highly, and completely weathered granite, and sampling of three-dimensional models for weathered and fresh granite supports this. In an engineering context, this suggests that joint spacing relationships in the various grades of weathered granite can be treated as the same regardless of weathering grade and that joint patterns in fresh granite must be evaluated separately. This knowledge could result in significant time and cost savings in the geotechnical characterization of these materials.

Ehlen, Judy

1999-12-01

197

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

198

Internal Tide Transformation and Oceanic Internal Solitary Waves  

Microsoft Academic Search

The transformation of internal tides, or long internal waves, as they propagate over the variable topography of the continental\\u000a slope and shelf is discussed. Development of a model to describe this transformation is presented and is based on the Korteweg-de\\u000a Vries equation. The model includes cubic as well as quadratic nonlinearity, dispersion, Earth’s rotation and quadratic dissipation.\\u000a An initial waveform,

Peter Holloway; Efim Pelinovsky; Tatiana Talipova

199

Stratospheric Tides and Data Assimilation  

NASA Technical Reports Server (NTRS)

In the upper stratosphere, the atmosphere exhibits significant diurnal and semi-diurnal tidal variations, with typical amplitude of about 2K in mid-latitudes. In this paper we examine how well the tidal variations in temperature are represented by the Goddard Geodesic Earth Orbiting Satellite (GEOS-2) data assimilation system. We show that the GEOS-2 atmospheric model is quite successful at simulating the tidal temperature variations. However, the assimilation of satellite temperature soundings significantly damps the simulated tides. The reason is because the tides are not well represented by the satellite retrievals used by the assimilation system (which have a typical tidal amplitude of around 1K). As a result of this study, we suggest improvements that should be made to the treatment of satellite soundings by the assimilation system.

Swinbank, R.; Orris, R. L.; Wu, D. L.

1999-01-01

200

Ocean Tides Lost and Found  

NSDL National Science Digital Library

The Moon's gravity imparts tremendous energy to the Earth, raising tides throughout the global oceans. What happens to all this energy? Scientists studying data from the orbiting TOPEX/Poseidon satellite believe they now have an answer. Users can read about the tidal energy imparted upon the earth by the Moon and where scientists believe it is dissipated, and view animations that show these effects.

201

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

202

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

203

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

204

Weatherizing America  

SciTech Connect

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

2009-01-01

205

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

206

Weathering Experiment  

NSDL National Science Digital Library

After discussing weathering and erosion in class, students are asked to do a small amount of research on different types of chemical weathering, physical weathering, and erosion processes (mostly out of their textbook). Outside of class students then dirty at least four similar dishes with the same type, thickness and aerial extent of food, preferably baked on to ensure maximum stick. One dish is set aside as a control (no weathering or erosion will occur for that dish). For each of the remaining three dishes, students devise an experiment that mimics some sort of chemical weathering, physical weathering, or erosion process (freeze/thaw, sand abrasion, oxidation, etc.). Prior to the experiments, the thickness of food is measured. Experiments are timed, and at the end of the experiment each plate is turned over to determine how much which method removed the greatest aerial extent of food. Experimental results are compared to the control plate to determine the actual effectiveness. Erosion/weathering rates are determined by dividing the thickness of food removed by the experimental time. Students then calculate how long it would take to remove a pile of food the size of the Geology building (assume a 50 m radius sphere), and to remove an amount of food equivalent to the depth of the Grand Canyon. Students then compare these results to rock erosion and weathering rates, performing similar calculations using these "real" rates (see the full project description for details). Photos of each step and the scientists are encouraged in their 2-3 page writeup.

Stelling, Pete

207

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 ...

Miss Emily

2010-01-29

208

Gravestone Weathering  

NSDL National Science Digital Library

In this activity (located on pages 9-14 of PDF), learners visit a cemetery to examine the distinguishing characteristics of rock weathering. After researching stone weathering and acid rain, learners apply their knowledge to collect data related to chemical decomposition and physical disintegration at a cemetery site. This detailed lesson guide includes tips for educators, pre/post activity suggestions, hands-outs, and background information.

Wiberg, Leanne; History, National M.

2000-01-01

209

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

210

The Tides Of Time Issue 31  

E-print Network

The Tides of Time Issue 31 • Michaelmas Term 2005 • revised August 2010 The Oxford University Doctor Who Society Magazine That’s weird. The Tides of Time 31 • 2 • M ich aelm as Term 2005 The Tides of Time Issue 31 • Michaelmas Term 2005 • revised... of The Tides of Time 31 • 3 • M ich aelm as Term 2005 planets have a north’ line was surely that the Doctor wasn’t pretending to be a northerner - he was one, from northern Gallifrey. I also feared that, as Rose is already a Londoner, the Doctor’s south...

2010-01-01

211

Tide effects removed from well tests  

SciTech Connect

To avoid distorted data when analyzing well pressure tests of permeable offshore reservoirs, one needs to account for periodic ocean tidal stress. Quartz-crystal bottom hole pressure recorders provide a high resolution of reservoir pressure but also measures pressure fluctuations from tidal effects during well testing. Periodic oscillations in the reservoir pressure are due to the three mechanisms: solid earth tide; barometric tide/effect; and ocean tide. The paper uses sample data from an offshore reservoir to illustrate how tide effects can be identified in the data and the correction procedure to use to remove these effects.

Aase, E.P.B.; Jelmert, T.A. [Norwegian Inst. of Technology, Trondeim (Norway); Vik, S.A. [Saga Petroleum A.S., Sandvika (Norway)

1995-05-01

212

New aspects of the equilibrium pole tide  

NASA Technical Reports Server (NTRS)

A new spherical harmonic algorithm is developed for the calculation of the loading and self-gravitating equilibrium pole tide. Based on a suggestion of Dahlen (1976), this approach minimizes the distortions in tide height caused by an incomplete representation of the ocean function. With slight modification this approach easily could be used to compute self-gravitating and loading lunisolar tides as well. Using the algorithm, the static pole tide is compared with tide observations at a variety of locations around the world, and statistically significant evidence for pole tide enhancements is found in midocean as well as the shallow seas. Also included is a reinvestigation of the effect of the static tide on the Chandler-wobble period. The difference between the wobble period of an oceanless elastic earth with a fluid core (Smith and Dahlen, 1981) and the period of an earth minus static oceans yields a 7.4-day discrepancy. It is concluded from tide observations that much of the discrepancy can probably be accounted for by nonequilibrium pole-tide behavior in the deep oceans.

Dickman, S. R.; Steinberg, D. J.

1986-01-01

213

AGAINST THE TIDE A Critical Review by Scientists of  

E-print Network

AGAINST THE TIDE A Critical Review by Scientists of How Physics and Astronomy Get Done Martín López Corredoira & Carlos Castro Perelman (Eds.) #12;Against the Tide 2 Against the Tide. A Critical Review

Rodriguez, Carlos

214

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

215

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.

216

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

217

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 constituents and comparison with a recent ocean tide model Vergnolle, M.1,* , M.-N. Bouin2 , L. Morel1 , F estimates of ocean tide loading in NW-France Corresponding author: Mathilde VERGNOLLE Phone: 00 33 4

Paris-Sud XI, Université de

218

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

219

Putting Weather into Weather Derivatives  

NASA Astrophysics Data System (ADS)

Just as weather forecasting has a colorful and often farsighted history within geophysics, financial mathematics has a long and turbulent history within mathematics. Thus it is no surprise that the intersection of real physics and real financial mathematics provides a rich source of problems and insight in both fields. This presentation targets open questions in one such intersection: quantifying ``weather risk.'' There is no accepted (operational) method for including deterministic information from simulation models (numerical weather forecasts, either best guess or by ensemble forecasting methods), into the stochastic framework most common within financial mathematics. Nor is there a stochastic method for constructing weather surrogates which has been proven successful in application. Inasmuch as the duration of employable observations is short, methods of melding short term, medium-range and long term forecasts are needed. On these time scales, model error is a substantial problem, while many methods of traditional statistical practice are simply inappropriate given our physical understanding of the system. A number of specific open questions, along with a smaller number of potential solutions, will be presented. >http://www.maths.ox.ac.uk/~lenny/WeatherRisk

Smith, L. A.; Smith, L. A.

2001-12-01

220

Accuracy assessment of recent ocean tide models  

Microsoft Academic Search

Over 20 global ocean tide models have been developed since 1994, primarily as a consequence of analysis of the precise altimetric measurements from TOPEX\\/POSEIDON and as a result of parallel developments in numerical tidal modeling and data assimilation. This paper provides an accuracy assessment of 10 such tide models and discusses their benefits in many fields including geodesy, oceanography, and

C. K. Shum; P. L. Woodworth; O. B. Andersen; G. D. Egbert; O. Francis; C. King; S. M. Klosko; C. Le Provost; X. Li; J.-M. Molines; M. E. Parke; R. D. Ray; M. G. Schlax; D. Stammer; C. C. Tierney; P. Vincent; C. I. Wunsch

1997-01-01

221

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

222

Precise datum control for pressure tide gauges  

Microsoft Academic Search

Pressure tide gauges are employed at many locations around the world, and are of particular importance in environmentally hostile areas. This article describes a method for the precise datum control of sea level records from pressure tide gauges which accommodates instrumental drifts in pressure transducers and variations in the ocean itself caused by density changes. By means of an additional

P. L. Woodworth; J. M. Vassie; R. Spencer; D. E. Smith

1996-01-01

223

NOS Tides and Water Levels Discovery Kit  

NSDL National Science Digital Library

National Ocean Service (NOS) scientists collect, study, predict and disseminate information about tides and water levels. Tutorial introduces the causes and variations of tides and currents, their impacts on human activities, navigation and organisms. Lesson plans include data for classroom activities, as well as resource links and teacher guides. A NSTA SciLinks selected site.

224

Wacky Weather  

NSDL National Science Digital Library

This 5-lesson unit gives students practice in using calculating, graphing and modeling skills to analyze varoius aspects of weather. Students calculate fractions of a set of rainfall data, graph damage costs of selected hurricanes, and make Venn diagrams to compare droughts and hurricanes. Visuals and student handouts are provided.

Barbara Chichetti

2002-01-01

225

Today's Weather  

NSDL National Science Digital Library

This activity is part of Planet Diary and contains an online exploration of weather maps. Students use current maps to learn about and locate different features such as low-pressure areas and fronts. They then explore how these are related to severe storms.

226

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.

Mission Science Workshop

2013-01-01

227

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.

228

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

229

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

230

Differences Between Climate and Weather  

NSDL National Science Digital Library

This activity will provide students with first hand knowledge of local weather changes and how they relates to local climates. After this activity students will understand the general distinctions between weather and climate, that daily weather measurements are highly variable compared to long-term climate data, and appreciate the difficulty of identifying climate trends based on limited data. The instructor guide contains detailed background material, learning goals, alignment to national standards, grade level/time, details on materials and preparation, procedure, assessment ideas, and modifications for alternative learners.

231

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

232

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

233

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

234

Weather Observations  

NSDL National Science Digital Library

We will be observing the weather in our enviornment. Post your observations. Take a hike! Tell us what you see! Make sure and note the date/time/season. Take a walk in your neighboorhood- what signs show you the current season? Vacation? Make observations about the place you visited. Make obseravtions every week! Keep a journal about the changes you observe! Winter Storm ImageSeasonal ChangesAround the WorldSeasonsSeasons of the Year ...

sarahnp

2011-07-18

235

Pole tide in the Baltic Sea  

NASA Astrophysics Data System (ADS)

The pole tide, which is driven by the Chandler Wobble, has a period of about 14 months and typical amplitudes in the World Ocean of ˜0.5 cm. However, in the Baltic Sea the pole tide is anomalously high. To examine this effect we used long-term hourly sea level records from 23 tide gauges and monthly records from 64 stations. The lengths of the series were up to 123 years for hourly records and 211 years for monthly records. 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 the Baltic Sea. The height of the pole tide was found to gradually increase from the entrance (Danish Straits, 1.5-2 cm) to the northeast end of the 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 the 19th and 20th centuries.

Medvedev, I. P.; Rabinovich, A. B.; Kulikov, E. A.

2014-03-01

236

Tide: Achieving Self-Scaling in Virtualized Datacenter Management Middleware  

E-print Network

Tide: Achieving Self-Scaling in Virtualized Datacenter Management Middleware Shicong Meng, Ling Liu of Tide, a self-scaling framework for virtu- alized datacenter management. A salient feature of Tide middleware. We eval- uate the effectiveness of Tide with both synthetic and real world workloads. Our results

Liu, Ling

237

Bureau of Commercial Fisheries Symposium on Red Tide  

E-print Network

21 Bureau of Commercial Fisheries Symposium on Red Tide By James E. Sykes Marine Biological, Donald L. McKernan, Director Bureau of Commercial Fisheries Symposium on Red Tide By James E. Sykes causing Red-Tide blooms as deduced from field observations 2 Red- Tide research at the Florida State

238

LECTURES ON TIDES UNIS, Longyearbyen, 26 -30 Sept. 2011  

E-print Network

LECTURES ON TIDES UNIS, Longyearbyen, 26 - 30 Sept. 2011 by B. Gjevik Department of Mathematics Introduction 3 2 Tide generating force 5 3 Harmonic decomposition of the tide generating force 10 4 Ocean closely associated with the flow of time as the very name tides indicates. When Newton (1697) first

Gjevik, Bjørn

239

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

240

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 d i d tide significant inter-annual variations. 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 a QBO with variable periods around 27 months and zonal wind amplitudes close to 20 m/s at 30 lan, 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 mechanisms, we discuss (a) the relative importance of the linearized advection terms that involve the meridional and vertical winds of the diurnal tide and (b) the effects momentum deposition from GWs filtered by the QBO.

Mayr, Hans G.; Mengel, John G.

2004-01-01

241

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

242

Observations of the internal tide on the California continental margin near Monterey Bay  

NASA Astrophysics Data System (ADS)

Observations of the semidiurnal internal tide on the California continental margin between Monterey Bay and Point Sur confirm the existence of northward energy flux predicted by numerical models of the region. Both a short-duration tide-resolving survey with expendable profilers and a multi-week timeseries from FLIP measured northward flux in the mean, supporting the hypothesis that topographic features off Point Sur are the source of the strong internal tides observed in Monterey Canyon. However, the observed depth-integrated semidiurnal flux of 450±200 W m-1 is approximately twice as large as the most directly-comparable model and FLIP results. Though dominated by low modes with O(100 km) horizontal wavelengths, a number of properties of the semidiurnal internal tide, including kinetic and potential energy, as well as energy flux, show lateral variability on O(5 km) scales. Potential causes of this spatial variability include interference of waves from multiple sources, the sharp delineation of beams generated by abrupt topography due to limited azimuthal extent, and local generation and scattering of the internal tide into higher modes by small-scale topography. A simple two-source model of a first-mode interference pattern reproduces some of the most striking aspects of the observations.

Terker, Samantha R.; Girton, James B.; Kunze, Eric; Klymak, Jody M.; Pinkel, Robert

2014-07-01

243

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.

244

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.

245

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

246

Nonlinear tides in close binary systems  

E-print Network

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: ...

Weinberg, Nevin N.

247

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

248

Red Tide and Harmful Algal Blooms  

NSDL National Science Digital Library

This Project Oceanography pdf document contains information and activities related to red tide and harmful algal blooms (HABs). The activities and lesson plans are designed for elementary school, middle school, and may be adapted for high school students. Articles include: harmful algal blooms, Florida red tide, implications of harmful algal blooms, and student information about harmful algal blooms. Activities are introduced with background information and include: "Growing Algae" and "Algal Explosion." The document also features activity extension projects and a glossary of terms.

Project Oceanography

249

Red Tide Current Status Statewide Information  

NSDL National Science Digital Library

This summary report of current red tide conditions around Florida includes a map of sampling results and regional status reports. Reports are generally updated on Friday afternoon and additional information, if available, is provided on Tuesday afternoon. The web page also includes links to hotlines and reporting sites for red tide effects on marine animals and humans, shellfish information, volunteer opportunities, subscriptions, and related websites.

250

Global charts of ocean tide loading effects  

Microsoft Academic Search

Global ocean tide loading charts of the radial displacement, the potential divided by g (gravity acceleration), and the gravity effect have been computed using the 11 constituents M2, S2, N2, K2, K1, O1, P1, Q1, Mf, Mm, Ssa of Schwiderski's tide model. These new charts have a resolution of 1°×1° on the continents as well as on the oceanic area.

O. Francis; P. Mazzega

1990-01-01

251

Mapping hurricane rita inland storm tide  

USGS Publications Warehouse

Flood-inundation data are most useful for decision makers when presented in the context of maps of affected communities and (or) areas. But because the data are scarce and rarely cover the full extent of the flooding, interpolation and extrapolation of the information are needed. Many geographic information systems provide various interpolation tools, but these tools often ignore the effects of the topographic and hydraulic features that influence flooding. A barrier mapping method was developed to improve maps of storm tide produced by Hurricane Rita. Maps were developed for the maximum storm tide and at 3-h intervals from midnight (00:00 hours) through noon (12:00 hours) on 24 September 2005. The improved maps depict storm-tide elevations and the extent of flooding. The extent of storm-tide inundation from the improved maximum storm-tide map was compared with the extent of flood inundation from a map prepared by the Federal Emergency Management Agency (FEMA). The boundaries from these two maps generally compared quite well especially along the Calcasieu River. Also a cross-section profile that parallels the Louisiana coast was developed from the maximum storm-tide map and included FEMA high-water marks. ?? 2009 Blackwell Publishing Ltd.

Berenbrock, C.; Mason, R.R., Jr.; Blanchard, S.F.

2009-01-01

252

The impact of reflectivity correction and accounting for raindrop size distribution variability to improve precipitation estimation by weather radar for an extreme low-land mesoscale convective system  

NASA Astrophysics Data System (ADS)

Between 25 and 27 August 2010 a long-duration mesoscale convective system was observed above the Netherlands, locally giving rise to rainfall accumulations exceeding 150 mm. Correctly measuring the amount of precipitation during such an extreme event is important, both from a hydrological and meteorological perspective. Unfortunately, the operational weather radar measurements were affected by multiple sources of error and only 30% of the precipitation observed by rain gauges was estimated. Such an underestimation of heavy rainfall, albeit generally less strong than in this extreme case, is typical for operational weather radar in The Netherlands. In general weather radar measurement errors can be subdivided into two groups: (1) errors affecting the volumetric reflectivity measurements (e.g. ground clutter, radar calibration, vertical profile of reflectivity) and (2) errors resulting from variations in the raindrop size distribution that in turn result in incorrect rainfall intensity and attenuation estimates from observed reflectivity measurements. A stepwise procedure to correct for the first group of errors leads to large improvements in the quality of the estimated precipitation, increasing the radar rainfall accumulations to about 65% of those observed by gauges. To correct for the second group of errors, a coherent method is presented linking the parameters of the radar reflectivity-rain rate (Z - R) and radar reflectivity-specific attenuation (Z - k) relationships to the normalized drop size distribution (DSD). Two different procedures were applied. First, normalized DSD parameters for the whole event and for each precipitation type separately (convective, stratiform and undefined) were obtained using local disdrometer observations. Second, 10,000 randomly generated plausible normalized drop size distributions were used for rainfall estimation, to evaluate whether this Monte Carlo method would improve the quality of weather radar rainfall products. Using the disdrometer information, the best results were obtained in case no differentiation between precipitation type (convective, stratiform and undefined) was made, increasing the event accumulations to more than 80% of those observed by gauges. For the randomly optimized procedure, radar precipitation estimates further improve and closely resemble observations in case one differentiates between precipitation type. However, the optimal parameter sets are very different from those derived from disdrometer observations. It is therefore questionable if single disdrometer observations are suitable for large-scale quantitative precipitation estimation, especially if the disdrometer is located relatively far away from the main rain event, which was the case in this study. In conclusion, this study shows the benefit of applying detailed error correction methods to improve the quality of the weather radar product, but also confirms the need to be cautious using locally obtained disdrometer measurements.

Hazenberg, Pieter; Leijnse, Hidde; Uijlenhoet, Remko

2014-11-01

253

How stationary are the internal tides in a high-resolution global ocean circulation model?  

NASA Astrophysics Data System (ADS)

stationarity of the internal tides generated in a global eddy-resolving ocean circulation model forced by realistic atmospheric fluxes and the luni-solar gravitational potential is explored. The root mean square (RMS) variability in the M2 internal tidal amplitude is approximately 2 mm or less over most of the ocean and exceeds 2 mm in regions with larger internal tidal amplitude. The M2 RMS variability approaches the mean amplitude in weaker tidal areas such as the tropical Pacific and eastern Indian Ocean, but is smaller than the mean amplitude near generation regions. Approximately 60% of the variance in the complex M2 tidal amplitude is due to amplitude-weighted phase variations. Using the RMS tidal amplitude variations normalized by the mean tidal amplitude (normalized RMS variability (NRMS)) as a metric for stationarity, low-mode M2 internal tides with NRMS < 0.5 are stationary over 25% of the deep ocean, particularly near the generation regions. The M2 RMS variability tends to increase with increasing mean amplitude. However, the M2 NRMS variability tends to decrease with increasing mean amplitude, and regions with strong low-mode internal tides are more stationary. The internal tide beams radiating away from generation regions become less stationary with distance. Similar results are obtained for other tidal constituents with the overall stationarity of the constituent decreasing as the energy in the constituent decreases. Seasonal variations dominate the RMS variability in the Arabian Sea and near-equatorial oceans. Regions of high eddy kinetic energy are regions of higher internal tide nonstationarity.

Shriver, Jay F.; Richman, James G.; Arbic, Brian K.

2014-05-01

254

Development of compound microsatellite markers in red-tide-causing dinoflagellate Akashiwo sanguinea (Dinophyceae).  

PubMed

We isolated 13 polymorphic microsatellites from the red-tide causing dinoflagellate Akashiwo sanguinea. These loci were highly variable, with between 2 and 10 alleles per locus, and estimated gene diversity ranging from 0.08 to 0.82. These loci have the potential to reveal genetic structure and estimate gene flow among A. sanguinea populations. PMID:21564789

Cho, S-Y; Nagai, S; Nishitani, G; Han, M-S

2009-05-01

255

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

256

Jicamarca radar observations of the diurnal and semidiurnal tide in the troposphere and lower stratosphere  

NASA Astrophysics Data System (ADS)

The mesosphere-stratosphere-troposphere (MST) radar at Jicamarca, Peru (12°S, 77°W), made extended (15 day or longer) observations of the horizontal and vertical winds that were used to infer the diurnal and semidiurnal tides. The measurements were made during several months from mid-1997 through mid-1998 and using a higher-power transmitter and finer range resolution during 10 days of August 1998. The three-component winds are used to estimate amplitudes, phases, and momentum fluxes associated with the tides. Thermal forcing of the diurnal tide is also examined with diurnal water vapor heating rates calculated using data from the NASA Water Vapor Project (NVAP). For the region near Jicamarca the calculations from NVAP showed the temporal variability of the diurnal heating to be dominated by an annual cycle with maximum around the summer solstice. When projected into tidal modes, about 25% of the total water vapor heating rate amplitude near Jicamarca is found to be nonmigrating. The meridional amplitude of the semidiurnal tide was found to be generally greater than the zonal amplitude, although tidal theory predicts that the zonal amplitude should be much greater at the latitude of Jicamarca (assuming the tide was migrating). The phase of the semidiurnal tide lagged (by about 3 hours) the phase expected from surface pressure climatologies. According to tidal theory the migrating semidiurnal tide should transport little meridional momentum flux. However, substantial southward fluxes ( ~ -1 × 10-3 m2 s-2) were observed at Jicamarca, and the meridional component of momentum flux was typically larger in magnitude than the zonal component was. The diurnal tide was somewhat weaker, was less coherent, and transported less momentum. The semidiurnal tide had a very long vertical wavelength throughout the troposphere and into the lower stratosphere, while the diurnal tide was only observed to propagate at heights above the tropopause with a much shorter (~10 km) vertical wavelength. Below the tropopause the dominant diurnal motions were not traveling waves, but rather convective motions that exhibited little phase progression with altitude. These motions were broadly peaked in frequency around 24 hours and were presumably standing oscillations with no horizontal propagation and probably with small horizontal scale. Despite the lack of coherence of these quasi-diurnal motions, the associated vertical wind amplitudes were sizable (~0.02 m s-1), and thus the fluctuations can presumably transport significant horizontal momentum.

Riggin, Dennis M.; Kudeki, Erhan; Feng, Zhaomei; Sarango, Martin F.; Lieberman, Ruth S.

2002-04-01

257

Tides in asynchronous binary systems  

E-print Network

Stellar oscillations are excited in non-synchronously rotating stars in binary systems due to the tidal forces. Tangential components of the tides can drive a shear flow which behaves as a differentially forced rotating structure in a stratified outer medium. In this paper we show that our single-layer approximation for the calculation of the forced oscillations yields results that are consistent with the predictions for the synchronization timescales in circular orbits. In addition, calibrating our model results to fit Zahn's relationship between synchronization timescales and orbital separation, we are able to constrain the value of the kinematical viscosity parameter. For the 4Mo+5Mo binary modeled in this paper, the kinematical viscosity is in the range 0.0015 -- 0.0043 Ro^2/d for orbital periods in the range 2.5 -- 25 d. Furthermore, the energy dissipation rate due to the shear flow is found to decrease by ~2 orders of magnitude as synchronization is approached, implying that binary systems may approach synchronization relatively quickly but that it takes a much longer timescale to actually attain this condition. Our model can be used to calculate the energy dissipation rates throughout the orbital cycle for arbitrary values of eccentricity and stellar rotational velocity. We suggest that the asymmetric distribution of energy dissipation over the stellar surface may lead to the appearance of localized regions of enhanced surface activity.

Oswaldo Toledano; Edmundo Moreno; Gloria Koenigsberger; R. Detmers; Norbert Langer

2006-10-18

258

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

259

Weather, Information Security, and Markets  

Microsoft Academic Search

The most common examples of financial variables are traded assets such as stocks and bonds. Derivatives have greatly facilitated financial management, the most useful technique of which is hedging, a trading activity that aims to reduce exposure to risk. The weather derivatives market has similarities to both the potential evolution and pricing of information security derivatives. Financial markets and investors

Pythagoras Petratos

2007-01-01

260

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

261

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

262

The Global S$_1$ Ocean Tide  

NASA Technical Reports Server (NTRS)

The small S$_1$ ocean tide is caused primarily by diurnal atmospheric pressure loading. Its excitation is therefore unlike any other diurnal tide. The global character of $S-1$ is here determined by numerical modeling and by analysis of Topex/Poseidon satellite altimeter data. The two approaches yield reasonably consistent results, and large ( $ greater than $l\\cm) amplitudes in several regions are further confirmed by comparison with coastal tide gauges. Notwithstanding their excitation differences, S$-1$ and other diurnal tides are found to share several common features, such as relatively large amplitudes in the Arabian Sea, the Sea of Okhotsk, and the Gulf of Alaska. The most noticeable difference is the lack of an S$-1$ Antarctic Kelvin wave. These similarities and differences can be explained in terms of the coherences between near-diurnal oceanic normal modes and the underlying tidal forcings. While gravitational diurnal tidal forces excite primarily a 28-hour Antarctic-Pacific mode, the S$_1$ air tide excites several other near-diurnal modes, none of which has large amplitudes near Antarctica.

Ray, Richard D.; Egbert, G. D.

2003-01-01

263

Modulation of Late Cretaceous and Cenozoic climate by variable drawdown of atmospheric pCO2 from weathering of basaltic provinces on continents drifting through the equatorial humid belt  

NASA Astrophysics Data System (ADS)

The small reservoir of carbon dioxide in the atmosphere (pCO2) that modulates climate through the greenhouse effect reflects a delicate balance between large fluxes of sources and sinks. The major long-term source of CO2 is global outgassing from sea-floor spreading, subduction, hotspot activity, and metamorphism; the ultimate sink is through weathering of continental silicates and deposition of carbonates. Most carbon cycle models are driven by changes in the source flux scaled to variable rates of ocean floor production, but ocean floor production may not be distinguishable from being steady since 180 Ma. We evaluate potential changes in sources and sinks of CO2 for the past 120 Ma in a paleogeographic context. Our new calculations show that decarbonation of pelagic sediments by Tethyan subduction contributed only modestly to generally high pCO2 levels from the Late Cretaceous until the early Eocene, and thus shutdown of this CO2 source with the collision of India and Asia at the early Eocene climate optimum at around 50 Ma was inadequate to account for the large and prolonged decrease in pCO2 that eventually allowed the growth of significant Antarctic ice sheets by around 34 Ma. Instead, variation in area of continental basalt terranes in the equatorial humid belt (5° S-5° N) seems to be a dominant factor controlling how much CO2 is retained in the atmosphere via the silicate weathering feedback. The arrival of the highly weatherable Deccan Traps in the equatorial humid belt at around 50 Ma was decisive in initiating the long-term slide to lower atmospheric pCO2, which was pushed further down by the emplacement of the 30 Ma Ethiopian Traps near the equator and the southerly tectonic extrusion of SE Asia, an arc terrane that presently is estimated to account for 1/4 of CO2 consumption from all basaltic provinces that account for ~1/3 of the total CO2 consumption by continental silicate weathering (Dessert et al., 2003). A negative climate-feedback mechanism that (usually) inhibits the complete collapse of atmospheric pCO2 is the accelerating formation of thick cation-deficient soils that retard chemical weathering of the underlying bedrock. Nevertheless, equatorial climate seems to be relatively insensitive to pCO2 greenhouse forcing and thus with availability of some rejuvenating relief as in arc terranes or thick basaltic provinces, silicate weathering in this venue is not subject to a strong negative feedback, providing an avenue for ice ages. The safety valve that prevents excessive atmospheric pCO2 levels is the triggering of silicate weathering of continental areas and basaltic provinces in the temperate humid belt. Excess organic carbon burial seems to have played a negligible role in atmospheric pCO2 over the Late Cretaceous and Cenozoic.

Kent, D. V.; Muttoni, G.

2013-03-01

264

Controlling The Global Weather.  

NASA Astrophysics Data System (ADS)

the weather controller is extremely complex, the existence of the required technology is plausible in the time range of several decades.While the concept of controlling the weather has often appeared in science fiction literature, this statement of the problem provides a scientific basis and a system architecture to actually implement global weather control. Large-scale weather control raises important legal and ethical questions. The nation that controls its own weather will perforce control the weather of other nations. Weather "wars" are conceivable. An international treaty may be required, limiting the use of weather control technology.

Hoffman, Ross N.

2002-02-01

265

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

266

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

267

The IERS Special Bureau for Tides  

NASA Technical Reports Server (NTRS)

The Global Geophysical Fluids Center of the International Earth Rotation Service (IERS) comprises 8 special bureaus, one of which is the Special Bureau for Tides. Its purpose is to facilitate studies related to tidal effects in earth rotation. To that end it collects various relevant datasets and distributes them, primarily through its website at bowie.gsfc.nasa.gov/ggfc/tides. Example datasets include tabulations of tidal variations in angular momentum and in earth rotation as estimated from numerical ocean tide models and from meteorological reanalysis products. The web site also features an interactive tidal prediction "machine" which generates tidal predictions (e.g., of UT1) from lists of harmonic constants. The Special Bureau relies on the tidal and earth-rotation communities to build and enlarge its datasets; further contributions from this community are most welcome.

Ray, Richard D.; Chao, B. F.; Desai, S. D.

2002-01-01

268

Internal tide generation by arbitrary two-dimensional topography  

E-print Network

To date, analytical models of internal tide generation by two-dimensional ridges have considered only idealized shapes. Here, we advance the Green function approach to address the generation of internal tides by two-dimensional ...

Peacock, Thomas

269

The Tides Of Time Issue 33  

E-print Network

The Tides of Time Issue 33 Hilary Term 2010 Editor Adam Povey adam.povey@sjc.ox.ac.uk Contents: The Prophet 3 A tribute to Barry Letts (1925 – 2009) from Matthew Kilnurn Five Things Wrong with David Tennant's Doctor 9 Thomas Keyton presents a... Worldwide Ltd. Or any other copyright holders. All images obtained from the public domain without permission. Second printing, now with better grammar and fewer commas. The Passage of Time It has been far too long since an edition of Tides has been...

2010-01-01

270

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

271

From Tides to Mixing Along the Hawaiian Ridge  

E-print Network

From Tides to Mixing Along the Hawaiian Ridge Daniel L. Rudnick,1 * Timothy J. Boyd,2 Russell E tides to turbulence has been hypothesized to serve as a major energy pathway for ocean mixing. We of internal tidal energy flux observed at the ridge agrees with the predictions of internal tide models. Large

Kurapov, Alexander

272

The lunar tide in sporadic E R. J. Stening  

E-print Network

The lunar tide in sporadic E R. J. Stening School of Physics, University of New South Wales, Sydney. Some examples from Arecibo are displayed to show this. The eect of lunar tides should then modify the wind-shear theory in a manner that yields the observed features of the lunar tide in the critical

Paris-Sud XI, Université de

273

SMLTM simulations of the diurnal tide: comparison with UARS observations  

E-print Network

SMLTM simulations of the diurnal tide: comparison with UARS observations R. A. Akmaev1 , V. A seasonal variations of tides, a dominant compo- nent of the MLT dynamics. Simulations with the Spectral with the observations. The diurnal tide is generated by forcing speci®ed at the model lower boundary and by in situ

Paris-Sud XI, Université de

274

COUNTS OF RED TIDE ORGANISMS, Gymnodinium breve, AND  

E-print Network

369: COUNTS OF RED TIDE ORGANISMS, Gymnodinium breve, AND ASSOCIATED OCEANOGRAPHIC DATA FROMKernan, Director COUNTS OF RED TIDE ORGANISMS, Gymnodinium breve, AND ASSOCIATED OCEANOGRAPHIC DATA FROM FLORIDA OF RED TIDE ORGANISMS, Gymnodinium breve, AND ASSOCIATED OCEANOGRAPHIC DATA FROM FLORIDA WEST COAST, 1957

275

Progress Towards an Operational Model Recent red tides in 2006  

E-print Network

Progress Towards an Operational Model Recent red tides in 2006 dand 2007: Progress towards an operational model of Florida red tide onset, dispersal, and maintenance within the Gulf of Mexicowithin tides] ­ J J Walsh R Htides] J.J. Walsh, R.H. Weisberg, and C.A. Heil` #12;Center for Prediction

Meyers, Steven D.

276

New Miscellaneous Results in Tides from Topex/Poseidon  

NASA Technical Reports Server (NTRS)

This paper describes a variety of new results concerning ocean tides that have been derived from Topex/Poseidon satellite altimeter data. Most of these results are based on new tidal solutions employing nearly 8 years of data. The topics covered include internal tides and long-period tides.

Ray, Richard D.; Egbert, G.; Cartwright, D.; Smith, David E. (Technical Monitor)

2000-01-01

277

NLOADF: A program for computing ocean-tide loading  

Microsoft Academic Search

The loading of the Earth by the ocean tides produces several kinds of signals which can be measured by geodetic technique. In order to compute these most accurately, a combi- nation of global and local models of the ocean tides may be needed. The program NLOADF convolves the Green functions for loading with ocean tide models using a station-centered grid

Duncan Carr Agnew

1997-01-01

278

COUNTS OF RED-TIDE ORGANISMS, Gymnodinium breve, AND ASSOCIATED  

E-print Network

455: COUNTS OF RED-TIDE ORGANISMS, Gymnodinium breve, AND ASSOCIATED OCEANOGRAPHIC DATA FROM F. Pautzke, Commissioner Bureau of Commercial Fisheries, Donald L. McKernan, Director COUNTS OF RED-TIDE Acknowledgment 4 Literature cited 5 Explanation of column headings 7 Station data 7 iii #12;#12;COUNTS OF RED-TIDE

279

Body tides of a convecting, laterally heterogeneous, and aspherical Earth  

E-print Network

Body tides of a convecting, laterally heterogeneous, and aspherical Earth Laurent Me´tivier1 November 2008. [1] Precise knowledge of Earth's body tides is crucial for correcting geodetic positioning, body tides are generally computed assuming a radially (or elliptically) stratified Earth. However

Conrad, Clint

280

TIDE-TSUNAMI INTERACTIONS Zygmunt Kowalik, Tatiana Proshutinsky,  

E-print Network

TIDE-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-period tsunami wave rides on the longer-period tides. The question is whether these two waves can be superposed

Kowalik, Zygmunt

281

Nonlinear disintegration of the internal tide Karl R. Helfrich1  

E-print Network

Nonlinear disintegration of the internal tide Karl R. Helfrich1 and Roger H. J. Grimshaw2 1 The disintegration of a first-mode internal tide into shorter solitary-like waves is considered. Because observations frequently show both tides and waves with amplitudes beyond the re- strictions of weakly nonlinear theory

282

Variations of the age of tides in the global oceans  

Microsoft Academic Search

Earlier studies on the age of tide dealt mostly with the age of the semi?diurnal tide in the Atlantic and Pacific Oceans. In these studies, the variations of the age of tide were determined making use of recorded tidal data up to and including the 1960s. In the present study, all available tidal data till the mid 1980s are utilized

T. S. Murty; R. Côté

1987-01-01

283

Tide-surge Interaction Intensified by the Taiwan Strait  

Microsoft Academic Search

The Taiwan Strait is a long and wide shelf-channel where the hydrodynamics is extremely complex, being characterized by strong tides, and where storm surges frequently occur during the typhoon season. Obvious oscillations due to tide-surge interaction were observed by tide gauges along the northern Fujian coast, the west bank of the Taiwan Strait, during Typhoon Dan (1999). Numerical experiments indicate

Wen-Zhou Zhang; Fengyan Shi; Hua-Sheng Hong; Shao-Ping Shang; James T. Kirby

2010-01-01

284

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.

285

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

286

NOAA New England Red Tide Information Center: More About Red Tides and Harmful Algal Blooms  

NSDL National Science Digital Library

This web page features links to information about NOAA-funded harmful algal bloom (HAB) research, HAB species, and HAB toxins and their impacts on humans, marine environments, and coastal economies. It also offers a brief description of Red Tide.

National Ocean Service (NOS)

287

The pricing of degree-day weather options  

Microsoft Academic Search

This paper presents a model and framework for pricing degree-day weather derivatives when the weather variable is a non-traded asset. Using daily weather data from 1840S1996, it is shown that a degree-day weather index exhibits stable volatility and satisfies the random walk hypothesis. The options prices from the recommended model are compared to a typical insurance-type model. The results show

Calum G. Turvey

2005-01-01

288

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.

289

Wave and tide powered generation apparatus  

Microsoft Academic Search

A wave and tide powered generation apparatus includes a frame which is fixed relative to the varying level of the body of water, and includes a float operably associated with the frame for movement in response to the varying level of the body of water. A rotatable drum is attached to the float and has a drive line with a

Suggs

1985-01-01

290

Mass. Declares a Red Tide Disaster  

NSDL National Science Digital Library

This CBS news article provides very general information about the massive red tide outbreak in New England in 2005. The article states that the outbreak is costing the shellfish industry $3 million per week, forcing Massachusetts to declare a state of emergency. The article features related external links.

CBS; Associated Press

291

Parents Who Moved against the Tide.  

ERIC Educational Resources Information Center

This article recounts the historical discrimination against children with mental retardation and the extraordinary efforts made by parents of children with disabilities to speak out against the tide that dehumanized their children. The growth of national, state, and local Arcs and parent advocacy efforts are discussed. (Contains 5 references.) (CR)

Perske, Robert

2003-01-01

292

Tide Pools of Carrigathorna and Barloge Creek  

Microsoft Academic Search

An ecological account is given of tide pools on the remote promontory of Carrigathorna, formed of Devonian slates on edge, on the open Atlantic coast, and on a sheltered but otherwise similar slate reef nearby. Both sites are at the entrance to Lough Ine, County Cork, Republic of Ireland. In addition to its immediate ecological concern, this study is intended

Susan Goss-Custard; Jane Jones; J. A. Kitching; T. A. Norton

1979-01-01

293

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

294

Tide Pools and the Life Within Them  

NSDL National Science Digital Library

This winning entry in the museum's Young Naturalist Awards 2001 by Talia, a 13 year old student from California, examines tidal pools and the animals that live in them. Her narrative essay reports on her three week study of the marine life she found in Doheny State Beach's tide pools.

295

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

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

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

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

The Weather Man  

NSDL National Science Digital Library

This project is designed to let you be "The Weather Man" and control the weather through simulation, and hands on experience, followed by guided questioning 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. How does humility play a role in weather? How does more or less change weather? 2. What is water vapor? Where does it come from? 3. What happens when the weather drops below zero degrees? ...

Grasser, Mrs. E.

2012-09-27

300

Numerical simulation of the barotropic tides in the Tunisian Shelf and the Strait of Sicily  

NASA Astrophysics Data System (ADS)

We have investigated the barotropic tides in the Tunisian shelf and the Strait of Sicily using the Regional Ocean Modelling System (ROMS) with very high-resolution. Model performance was evaluated with respect to tide gauge, satellite data, and current meter measurements. The model fields faithfully reproduced the major feature of the barotropic tidal currents and agreed well with existing tidal elevation and phase observations. General features for the various semidiurnal constituents are nearly similar to each other with maximum amplitude in the Gulf of Gabes. The larger tidal currents occur over the continental shelves. In the Adventure Bank, the current is essentially of diurnal type whereas in the Gulf of Gabes it is of semidiurnal type. Tidal energy lost, which is primarily due to bottom stress dissipation, is predominantly in the Gulf of Gabes (˜ 61%), the Strait of Sicily, and the Strait of Messina. The forcing function for internal tides shows for both M 2 and K 1 constituents, significant spatial variability in the Strait of Sicily. This suggests that some internal tides will be generated in these regions and could thus explain the observed strong diurnal internal waves in the Adventure Bank.

Abdennadher, Jihène; Boukthir, Moncef

2006-12-01

301

Harmonic analysis of tides and tidal currents in South San Francisco Bay, California  

USGS Publications Warehouse

Water level observations from tide stations and current observations from current-meter moorings in South San Francisco Bay (South Bay), California have been harmonically analysed. At each tide station, 13 harmonic constituents have been computed by a least-squares regression without inference. Tides in South Bay are typically mixed; there is a phase lag of approximately 1 h and an amplification of 1??5 from north to south for a mean semi-diurnal tide. Because most of the current-meter records are between 14 and 29 days, only the five most important harmonics have been solved for east-west and north-south velocity components. The eccentricity of tidal-current ellipse is generally very small, which indicates that the tidal current in South Bay is strongly bidirectional. The analyses further show that the principal direction and the magnitude of tidal current are well correlated with the basin bathymetry. Patterns of Eulerian residual circulation deduced from the current-meter data show an anticlockwise gyre to the west and a clockwise gyre to the east of the main channel in the summer months due to the prevailing westerly wind. Opposite trends have been observed during winter when the wind was variable. ?? 1985.

Cheng, R.T.; Gartner, J.W.

1985-01-01

302

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

303

Variable Oort cloud flux due to the Galactic tide  

Microsoft Academic Search

We review the evidence that the slowly varying Galactic tidal torque dominates in making Oort cloud comets observable, both for the present and over long time scales (Cel. Mech. Dyn. Astron., 13 (1992); ApJLett L41 (1996)). If this is correct, then there is a substantial time-dependence to the flux of earth crossing comets that originate in the Oort comet cloud

J. J. Matese; P. G. Whitman; D. P. Whitmire

1997-01-01

304

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).

Cris Garcia

2001-06-22

305

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

306

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

307

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.

Institution, Woods H.

308

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

309

Weathering and Erosion  

NSDL National Science Digital Library

This unit provides an introduction for younger students to the concepts of weathering and erosion. Topics include types of weathering (physical versus chemical), rates of weathering, and weathering products (soil). The section on erosion explains the importance of water and gravity in the process, and discusses some of the more important erosional agents such as wind, water and ice, streams and glaciers. A vocabulary list and downloadable, printable student worksheets are provided.

Medina, Philip

2010-09-07

310

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

311

Web Weather for Kids  

NSDL National Science Digital Library

This set of resources for younger students includes activities and information on thunderstorms, tornadoes, hurricanes, blizzards and clouds: how they form, and how they impact our lives. There are games about clouds, stories about extreme weather events, and a set of activities in which students create simulations of various weather phenomena such as fog, clouds, tornadoes, and others. The 'Recipe for Weather' segment provides an overview of four atmospheric properties (temperature, pressure, volume, and density) which drive most weather phenomena.

312

Tides and the Evolution of Planetary Habitability  

E-print Network

Tides raised on a planet by its host star's gravity can reduce a planet's orbital semi-major axis and eccentricity. This effect is only relevant for planets orbiting very close to their host stars. The habitable zones of low-mass stars are also close-in and tides can alter the orbits of planets in these locations. We calculate the tidal evolution of hypothetical terrestrial planets around low-mass stars and show that tides can evolve planets past the inner edge of the habitable zone, sometimes in less than 1 billion years. This migration requires large eccentricities (>0.5) and low-mass stars (<0.35 M_Sun). Such migration may have important implications for the evolution of the atmosphere, internal heating and the Gaia hypothesis. Similarly, a planet detected interior to the habitable zone could have been habitable in the past. We consider the past habitability of the recently-discovered, ~5 M_Earth planet, Gliese 581 c. We find that it could have been habitable for reasonable choices of orbital and physical properties as recently as 2 Gyr ago. However, when we include constraints derived from the additional companions, we see that most parameter choices that predict past habitability require the two inner planets of the system to have crossed their mutual 3:1 mean motion resonance. As this crossing would likely have resulted in resonance capture, which is not observed, we conclude that Gl 581 c was probably never habitable.

Rory Barnes; Sean N. Raymond; Brian Jackson; Richard Greenberg

2008-07-04

313

Global charts of ocean tide loading effects  

SciTech Connect

Global ocean tide loading charts of the radial displacement, the potential divided by g (gravity acceleration), and the gravity effect have been computed using the 11 constituents M{sub 2}, S{sub 2}, N{sub 2}, K{sub 2}K{sub 1}, O{sub 1}, P{sub 1}, Q{sub 1}, M{sub f}, M{sub m}, S{sub s a} of Schwiderski's tidal model. These new charts have a resolution of 1{degree}{times}1{degree} on the continents as well as on the oceanic area. A description of Farrell's convolution method to compute the loading effects is given, and an estimate of the numerical errors leads to the conclusion that these global charts have a precision better than 2.5% independent of the accuracy of Schwiderski's maps. The current approximation of the loading effects by a proportionality relation with the local oceanic tides is also compared with Farrell's convolution method. Departures of several centimeters systematically appear, in particular over the continental shelves. The authors then show that the maps of the oceanic tides deduced from satellite altimetry could be corrected for the loading effect by an iterative computational procedure based on their algorithm of Farrell's convolution.

Francis, O.; Mazzega, P. (CNES, Toulouse (France))

1990-07-15

314

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

315

Aviation weather services  

NASA Technical Reports Server (NTRS)

The primary responsibilities of the National Weather Service (NWS) are to: provide warnings of severe weather and flooding for the protection of life and property; provide public forecasts for land and adjacent ocean areas for planning and operation; and provide weather support for: production of food and fiber; management of water resources; production, distribution and use of energy; and efficient and safe air operations.

Sprinkle, C. H.

1983-01-01

316

Weather Fundamentals: Meteorology. [Videotape].  

ERIC Educational Resources Information Center

The videos in this educational series, for grades 4-7, help students understand the science behind weather phenomena through dramatic live-action footage, vivid animated graphics, detailed weather maps, and hands-on experiments. This episode (23 minutes) looks at how meteorologists gather and interpret current weather data collected from sources…

1998

317

Severe Weather Perceptions.  

ERIC Educational Resources Information Center

Severe weather is an element of nature that cannot be controlled. Therefore, it is important that the general public be aware of severe weather and know how to react quickly and appropriately in a weather emergency. This study, done in the community surrounding the Southern Illinois University at Carbondale, was conducted to compile and analyze…

Abrams, Karol

318

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

319

Hot Weather Tips  

MedlinePLUS

... Form - A A + A You are here Home HOT Weather Tips Printer-friendly version We all suffer in hot weather. However, for elderly and disabled people and ... stress and following these tips for dealing with hot weather. Wear cool clothing: See that the person ...

320

Weather Maps in Motion  

NSDL National Science Digital Library

In this activity, students learn to interpret current weather maps. They will observe weather map loop animations on the internet, learn the concept of Zulu time (Universal Time Coordinated, UTC) and visualize the movement of fronts and air masses. They will then analyze a specific weather station model, generate a meteogram from their observations, and answer a set of questions about their observations.

Charles Burrows

321

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

322

Weather affects us  

NSDL National Science Digital Library

2nd grade weather unit. The students will learn how weather affects us in our daily lives Read and view the video on meteorologists Kid Meteorologist Learn about clouds - watch S'cool Clouds All About Clouds Do scholastic: weather watch and game Weather Read winter storms Interactive Weather Web Pages Read a reason for the season A Reason for the Season Read about precipitation Precipitation Read and view video on flooding Flood: Farming and Erosion Read about air pressure It's a Breeze: How Air Pressure Affects You Read about Hurricanes Hurricanes Do the activities and read ...

Kimmy

2009-11-09

323

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

324

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

325

Impacts of vertically propagating tides on the mean state of the ionosphere-thermosphere system  

NASA Astrophysics Data System (ADS)

The National Center for Atmospheric Research Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIE-GCM) is utilized to understand the role that upward propagating tides play in determining the zonal mean state of the ionosphere-thermosphere system. A sensitivity assessment of the TIE-GCM shows that TIE-GCM solutions greatly depend on the lower boundary conditions. We also establish the veracity of our TIE-GCM solutions within and above the dynamo region. To isolate the mean effects of tidal dissipation, differences between TIE-GCM simulations with and without lower boundary tidal forcing as specified by the Climatological Tidal Model of the Thermosphere are investigated. Dissipation of the DW1, (diurnal westward propagating tide with zonal wave number 1), diurnal eastward propagating tide with zonal wave number 3, and SW2 (semidiurnal tide with zonal wave number 2) explains most of ˜10-30 m s-1 seasonal and latitudinal variability in zonal winds within the dynamo region, with SW2 playing a greater role than ascribed in previous studies. Tidal dissipation at low latitudes causes a 9% decrease (30% increase) in [O] ([O2]) number densities near the F2 layer peak, leading to at least a 9% decrease in peak electron density (NmF2) throughout the year. F2 layer peak height (hmF2) differences of -4 to 2 km at low latitudes are explained by variations in the field-aligned plasma motion driven by meridional wind differences induced by tidal dissipation. Compositional effects are mainly driven by DW1 and SW2, which differs from previous interpretations of tidal-driven composition changes by DW1 "tidal mixing" exclusively. We suggest that tides may produce a net transport of constituents in the thermosphere similar to the way that, e.g., gravity waves can drive net transport of sodium in the mesosphere.

Jones, M.; Forbes, J. M.; Hagan, M. E.; Maute, A.

2014-03-01

326

A Synoptic Approach to Weather Conditions Discloses a Relationship With Ambulatory Blood Pressure in Hypertensives  

Microsoft Academic Search

BackgroundHigher blood pressure (BP) values in cold than in hot months has been documented in hypertensives. These changes may potentially contribute to the observed excess winter cardiovascular mortality. However, the association with weather has always been investigated by considering the relationship with a single variable rather than considering the combination of ground weather variables characterizing a specific weather pattern (air

Marco Morabito; Alfonso Crisci; Simone Orlandini; Giampiero Maracchi; Gian F. Gensini; Pietro A. Modesti

2008-01-01

327

Long-period perturbations in Starlette orbit and tide solution  

SciTech Connect

Continuous and dynamically consistent orbits have been computed using satellite laser ranging (SLR) data to Starlette for one-year period during 1976 and 1977 and the three-year period from 1983 through 1985. A low degree and order ocean tide solution, consisting of a total of 66 tidal parameters from 14 tidal constituents, was obtained in a combined solution using both the one-and three-year Starlette orbits. Yearly values for the second-degree annual tides, S{sub a}, which produce seasonal variations on the Starlette node, were obtained also. These variations were found to have year-to-year fluctuations of more than 25% about the mean value and produced significant long-period perturbations in the Starlette orbit. The Starlette tide solution is in good agreement with the Schwiderski tide solutions and with other satellite solutions, including multi-satellite tide solutions. The average uncertainties are approximately 0.1 cm for the estimated semidiurnal and diurnal tides and 0.4 cm for the long-period tides. The discrepancies of effective k{sub 2} inferred from the Starlette tide solution and other tide solutions are less than 0.01. The tide solutions were evaluated using orbit fits of a three-year LAGEOS and a one-year Starlette long arc. The results indicate that the Starlette tide solution produces significantly improved orbit fits for both LAGEOS and Starlette. The uncertainties for the estimated tide model coefficients were used to predict tidal errors for the LAGEOS orbit and were found to be consistent with the apparent tidal errors present in this orbit. The computed secular change in the Moon's mean motion due to tidal dissipation is {minus}24.8 {plus minus} 0.8 arc second/century{sup 2}, which is in good agreement with the results obtained from other investigations.

Cheng, M.K.; Shum, C.K.; Eanes, R.J.; Schutz, B.E.; Tapley, B.D. (Univ. of Texas, Austin (United States))

1990-06-10

328

Algae That Cause Red Tide Found Off Maine Coast  

NSDL National Science Digital Library

This Bangor Daily News article provides general information about red tide in Maine and efforts being done to track the harmful algal bloom (HAB) events. There are four major red tide causing algae in Maine: Alexandrium, Dinophysis, Prorocentrum and Pseudonitzschia. These algae can cause serious health problems in humans and other marine animals. The &amp;quot;first alert system&amp;quot; now in place now monitors for sunlight and nutrient concentrations that may lead to red tide events.

Edgecomb, Misty; News, Bangor D.

329

Lunar semidiurnal tide in the thermosphere under solar minimum conditions  

NASA Astrophysics Data System (ADS)

Renewed interest in lunar tidal influences on the ionosphere-thermosphere (IT) system has emerged in connection with recent studies of possible connections between stratospheric warmings and enhanced lunar tidal perturbations of the equatorial ionosphere. By virtue of its gravitational force, the Moon produces perturbations in the temperature, density, pressure, and winds throughout Earth's atmosphere. Lunar tidal winds in the dynamo region (~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. Decades-long satellite data sets now exist that can provide a global perspective on lunar tidal oscillations, but this resource has not yet been exploited for this purpose. In this paper, we examine the global structure of the main M2 (period = 12.42 h) lunar tide through examination of temperatures measured by the Thermosphere Ionosphere Mesosphere Energetics and Dynamics SABER instrument at 110 km and densities at 360 and 480 km inferred from accelerometers on the CHAMP and Gravity Recovery and Climate Experiment satellites, respectively. Ten year mean SABER M2 temperature amplitudes are of order 5-10 K while the corresponding density perturbations during the 2007-2010 solar minimum period approach amplitudes of order 5% at 360 km and 10% at 480 km. The observed amplitudes are large enough to impose non-negligible day-to-day variability on the IT system. Global-Scale Wave Model simulations provide a theoretical and modeling context for interpreting these data, and moreover enable estimates of E- and F-region winds.

Forbes, Jeffrey M.; Zhang, Xiaoli; Bruinsma, Sean; Oberheide, Jens

2013-04-01

330

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

331

Severe Weather 101: Winter Weather Basics  

MedlinePLUS

... Educators For Students For Everyone Severe Weather 101 Thunderstorms Basics Types Detection Forecasting FAQ Tornadoes Basics Types ... moisture. What we do: NSSL researchers studied winter thunderstorms and found that there is some evidence that ...

332

National Weather Service- Severe Weather Awareness  

NSDL National Science Digital Library

This website provides access to information designed to protect and prepare individuals from severe weather. Materials presented here include forecasts for aviation and marine interests and the general public, maps, statistical data, educational materials, publications, and links to related sites.

333

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

334

Visit to an Ocean Planet - Timing the Tides  

NSDL National Science Digital Library

Tide tables, commonly seen in newspapers and on television in coastal areas, show that comparable local high and low tides occur almost one hour later from one day to the next. The motion of the Moon as it revolves around the Earth largely accounts for the time lag. Students participating in this activity will investigate this time lag by using the tide time diagram and instructions which are provided. They should be able to describe how and why the times of low and high tide change from one day to the next.

335

Vibrios associated with red tides caused by Mesodinium rubrum.  

PubMed Central

Vibrios were isolated from red tides caused by Mesodinium rubrum and also throughout the year in the Ria de Pontevedra, Spain. The isolates were grouped into 14 phena by numerical toxonomy. Strains associated with red tides were restricted to four phena: phena I and II were Vibrio alginolyticus, and phena III and IV were Vibrio tubiashii and Vibrio anguillarum, respectively. V. anguillarum-like strains (phena V through XI) predominated throughout the year outside the red tide areas. Cytotoxicity assays conducted in different poikilothermic and homoiothermic cell lines showed that cytotoxin production was not necessarily associated with the species selected during the red tides. PMID:2268167

Romalde, J L; Barja, J L; Toranzo, A E

1990-01-01

336

Precise Comparisons of Bottom-Pressure and Altimetric Ocean Tides  

NASA Technical Reports Server (NTRS)

A new set of pelagic tide determinations is constructed from seafloor pressure measurements obtained at 151 sites in the deep ocean. To maximize precision of estimated tides, only stations with long time series are used; median time series length is 567 days. Geographical coverage is considerably improved by use of the international tsunami network, but coverage in the Indian Ocean and South Pacific is still weak. As a tool for assessing global ocean tide models, the data set is considerably more reliable than older data sets : the root-mean-square difference with a recent altimetric tide model is approximately 5 mm for the M2 constituent. Precision is sufficiently high to allow secondary effects in altimetric and bottom-pressure tide differences to be studied. The atmospheric tide in bottom pressure is clearly detected at the S1, S2, and T2 frequencies. The altimetric tide model is improved if satellite altimetry is corrected for crustal loading by the atmospheric tide. Models of the solid body tide can also be constrained. The free corenutation effect in the K1 Love number is easily detected, but the overall estimates are not as accurate as a recent determination with very long baseline interferometry.

Ray, Richard D.

2013-01-01

337

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

338

TIDE: Lightweight Device Composition for Enhancing Tabletop Environments with Smartphone Applications  

E-print Network

TIDE: Lightweight Device Composition for Enhancing Tabletop Environments with Smartphone of applications. This paper pre- sents TIDE, a lightweight device composition middleware to bring existing smartphone applications onto the tabletop. Through TIDE, applications running on the smartphone are displayed

339

Southern Mildew Problems: Weather and Psychrometrics  

E-print Network

tvm predictor variables because cell sizes becam to srnall when mre variables were included. olaracteristics of the Respondents hst onefifth of the sample (18.3%) were born in Florida, with New York natives accounting for the next largest group... throughout Florida, Table 4 shows the average dew pint temperatures at nine weather stations. The underlined mmSmrs shw the dew pint tenperatures that are 55°F or higher, the break pint for mildew-safe humidity levels. 'Ihe further south the weather...

Peart, V.

1989-01-01

340

POPULATION SYNCHRONY WITHIN AND AMONG LEPIDOPTERA SPECIES IN RELATION TO WEATHER, PHYLOGENY, AND LARVEL PHENOLOGY  

EPA Science Inventory

1. The population dynamics of native herbivore species in central Appalachian deciduous forests were studied by analysing patterns of synchrony among intra- and interspecific populations and weather. 2. Spatial synchrony of 10 Lepidoptera species and three weather variables (min...

341

Introduction to Tides: The Tides of the Waters of New England and New York  

NASA Astrophysics Data System (ADS)

This interesting little book is not really about what its main title suggests, an introductory text on tides for oceanography students. Its subtitle gives more of a clue to its contents and intended readership. The author immediately points out in the preface that ‘this book is written for the many intelligent people who work or play along the coast between Sandy Hook and the Bay of Fundy.’In addition to discussing elementary tidal theory, the book describes in some detail the author's systematic analysis of coastal tides and currents in the New England and New York region. His analysis fits the solution of the telegrapher's equation to Tide Table predictions of tidal elevations and times of high water and slack current. In this way, Redfield separates the observed M2 tides in various straits, embayments, hydraulic channels, and estuaries into damped, progressive waves travelling in opposite directions. These waves arise through reflection of the primary wave at the head of an embayment or estuary, or through two primary waves entering a tidal strait or hydraulic channel from both ends.

Bowman, Malcolm J.

342

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

343

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

344

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

345

Tales of future weather  

NASA Astrophysics Data System (ADS)

Society is vulnerable to extreme weather events and, by extension, to human impacts on future events. As climate changes weather patterns will change. The search is on for more effective methodologies to aid decision-makers both in mitigation to avoid climate change and in adaptation to changes. The traditional approach uses ensembles of climate model simulations, statistical bias correction, downscaling to the spatial and temporal scales relevant to decision-makers, and then translation into quantities of interest. The veracity of this approach cannot be tested, and it faces in-principle challenges. Alternatively, numerical weather prediction models in a hypothetical climate setting can provide tailored narratives for high-resolution simulations of high-impact weather in a future climate. This 'tales of future weather' approach will aid in the interpretation of lower-resolution simulations. Arguably, it potentially provides complementary, more realistic and more physically consistent pictures of what future weather might look like.

Hazeleger, W.; van den Hurk, B. J. J. M.; Min, E.; van Oldenborgh, G. J.; Petersen, A. C.; Stainforth, D. A.; Vasileiadou, E.; Smith, L. A.

2015-02-01

346

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.

Hydrometeorological Prediction Center

2011-01-01

347

Backyard Weather Stations  

NSDL National Science Digital Library

Learn how to build your own backyard weather station with complete directions provided by FamilyEducation.com's Web site, Backyard Weather Stations. The site shows exactly what you'll need and how to build the necessary components (e.g., rain gauge and barometer), as well as how to keep records of the data collected. Parents and teachers will enjoy watching the kids "learn the basics of scientific observation and record-keeping while satisfying their natural curiosity about weather."

Randall, Dennis.

348

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

349

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

350

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

351

Everything Weather- Archived Data  

NSDL National Science Digital Library

Users can obtain current weather forecasts for their own areas by entering a ZIP code, or they can access a large archive of historic data on severe weather (tornadoes, hail, high winds, hurricanes). Materials presented in the archive include dates, times, and intensities of storms, a photo gallery, maps, radar and other satellite data, storm chaser reports, and links to other weather sites. Raw data can be found in several forms for teachers wishing to have unprocessed data to work with.

2001-01-01

352

National Weather Service  

NSDL National Science Digital Library

Sick and tired of the heat? Feel like it will never end? Then check out the National Weather Service's (NWS) Heat Wave, a site devoted to the extreme weather that is crippling the south. The NWS provides information on the heat index, heat's affect on the body, and how to beat the heat. For those who want an up-to-the-minute look at the weather, the site links to current conditions, forecasts, and watches and warnings.

353

Sea level variability in Long Island Sound  

Microsoft Academic Search

Sea level variability in Long Island Sound is examined at both tidal and subtidal frequencies over a 1-yr period. The sound\\u000a is found to be decoupled effectively from the lower Hudson Estuary at tidal frequencies. The predominantly semidiurnal tides\\u000a in the sound are forced by the oceanic tides transmitted from the mouth. There is a near fourfold amplification of the

Kuo-Chuin Wong

1990-01-01

354

Cockpit weather information needs  

NASA Technical Reports Server (NTRS)

The primary objective is to develop an advanced pilot weather interface for the flight deck and to measure its utilization and effectiveness in pilot reroute decision processes, weather situation awareness, and weather monitoring. Identical graphical weather displays for the dispatcher, air traffic control (ATC), and pilot crew should also enhance the dialogue capabilities for reroute decisions. By utilizing a broadcast data link for surface observations, forecasts, radar summaries, lightning strikes, and weather alerts, onboard weather computing facilities construct graphical displays, historical weather displays, color textual displays, and other tools to assist the pilot crew. Since the weather data is continually being received and stored by the airborne system, the pilot crew has instantaneous access to the latest information. This information is color coded to distinguish degrees of category for surface observations, ceiling and visibilities, and ground radar summaries. Automatic weather monitoring and pilot crew alerting is accomplished by the airborne computing facilities. When a new weather information is received, the displays are instantaneously changed to reflect the new information. Also, when a new surface or special observation for the intended destination is received, the pilot crew is informed so that information can be studied at the pilot's discretion. The pilot crew is also immediately alerted when a severe weather notice, AIRMET or SIGMET, is received. The cockpit weather display shares a multicolor eight inch cathode ray tube and overlaid touch panel with a pilot crew data link interface. Touch sensitive buttons and areas are used for pilot selection of graphical and data link displays. Time critical ATC messages are presented in a small window that overlays other displays so that immediate pilot alerting and action can be taken. Predeparture and reroute clearances are displayed on the graphical weather system so pilot review of weather along the route can be accomplished prior to pilot acceptance of the clearance. An ongoing multiphase test series is planned for testing and modifying the graphical weather system. Preliminary data shows that the nine test subjects considered the graphical presentation to be much better than their current weather information source for situation awareness, flight safety, and reroute decision making.

Scanlon, Charles H.

1992-01-01

355

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

356

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

357

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

358

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

359

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

360

Research-Based Teaching Unit on the Tides. Research Report  

ERIC Educational Resources Information Center

The aim of this study was to develop a new research-based learning unit for tides to be used in lower secondary schools. The learning unit was based on the scientific theory of tides, textbooks, and also an analysis of students' conceptions. Descriptions are included of the content and the teaching-learning activities of the unit. The teacher talk…

Viiri, Jouni; Saari, Heikki

2004-01-01

361

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...

362

From Tides to Mixing Along the Hawaiian Ridge  

Microsoft Academic Search

The cascade from tides to turbulence has been hypothesized to serve as a major energy pathway for ocean mixing. We investigated this cascade along the Hawaiian Ridge using observations and numerical models. A divergence of internal tidal energy flux observed at the ridge agrees with the predictions of internal tide models. Large internal tidal waves with peak-to-peak amplitudes of up

Daniel L. Rudnick; Timothy J. Boyd; Russell E. Brainard; Glenn S. Carter; Gary D. Egbert; Michael C. Gregg; Peter E. Holloway; Jody M. Klymak; Eric Kunze; Craig M. Lee; Murray D. Levine; Douglas S. Luther; Joseph P. Martin; Mark A. Merrifield; James N. Moum; Jonathan D. Nash; Robert Pinkel; Luc Rainville; Thomas B. Sanford

2003-01-01

363

Evidence of earthquake triggering by the solid earth tides  

Microsoft Academic Search

Clear evidence for earthquake triggering by the earth tides has remained elusive for more than a century. Using the largest global earthquake catalog available (the NEIC catalog with 442412 events), we observe a clear correlation (with ?99% confidence) between the phase of the solid Earth tide and the timing of seismic events: earthquakes occur slightly more often at the time

Laurent Métivier; Olivier de Viron; Clinton P. Conrad; Stéphane Renault; Michel Diament; Geneviève Patau

2009-01-01

364

Tide?surge interaction in the Gulf of Suez, Egypt  

Microsoft Academic Search

A two?dimensional, nonlinear, vertically integrated model for the Gulf of Suez, Egypt, was used to simulate the interaction between tides and the surge heights resulting from a 15 m\\/s storm blowing from the northwestern direction for 24 hours. The results show that the predominant surges as well as the envelope of the tide plus surge curve are all negative throughout

M. A. Rady; T. S. Murty; J. O. Backhaus

1994-01-01

365

Interaction between storm surges and tides in shallow waters  

Microsoft Academic Search

The interaction between astronomical tides and storm surges in two different water bodies, namely the St. Lawrence estuary and the Suez Canal, is studied using simple analytical theories. Two parameters were derived that are of fundamental importance to this interaction. Based on the values of these parameters one should be able to determine with which state of the tide (rising,

T. S. Murty

1981-01-01

366

Ocean tide models for satellite geodesy and Earth rotation  

NASA Technical Reports Server (NTRS)

A theory is presented which predicts tides in turbulent, self-gravitating, and loading oceans possessing linearized bottom friction, realistic bathymetry, and continents (at coastal boundaries no-flow conditions are imposed). The theory is phrased in terms of spherical harmonics, which allows the tide equations to be reduced to linear matrix equations. This approach also allows an ocean-wide mass conservation constraint to be applied. Solutions were obtained for 32 long and short period luni-solar tidal constituents (and the pole tide), including the tidal velocities in addition to the tide height. Calibrating the intensity of bottom friction produces reasonable phase lags for all constituents; however, tidal amplitudes compare well with those from observation and other theories only for long-period constituents. In the most recent stage of grant research, traditional theory (Liouville equations) for determining the effects of angular momentum exchange on Earth's rotation were extended to encompass high-frequency excitations (such as short-period tides).

Dickman, Steven R.

1991-01-01

367

Experimental Research on Effect of Tide for Coastal Groundwater Table  

NASA Astrophysics Data System (ADS)

A tide simulation system based on two-way water pump technique is developed by authors. Using this system, the groundwater table fluctuation characteristics, relative over height of groundwater table, and influencing factors of over height are investigated. The experiment results indicate that the groundwater table fluctuation is of periodicity, and of asymmetry. The amplitude of groundwater table fluctuations decreases with the increase of the onshore distances. There are phase lags of groundwater table fluctuations for different monitoring points. The tide can cause remarkable over height of coastal groundwater table. The dominating factors bring about over height include tide amplitude, tide frequency and aquifer thickness. Under above experiment conditions, the maximum value of over height exceeded 50% of the maximal tide amplitude, and reached about 10% of aquifer thickness. So, over height is not a negligent factor of forecasting the groundwater resource gross in coastal area.

Wu, Long-hua; Zhuang, Shui-ying

2010-11-01

368

Orthogonal stack of global tide gauge sea level data  

NASA Technical Reports Server (NTRS)

Yearly and monthly tide gauge sea level data from around the globe are fitted to numerically generated equilibrium tidal data to search for the 18.6 year lunar tide and 14 month pole tide. Both tides are clearly evident in the results, and their amplitudes and phases are found to be consistent with a global equilibrium response. Global, monthly sea level data from outside the Baltic sea and Gulf of Bothnia are fitted to global atmospheric pressure data to study the response of the ocean to pressure fluctuations. The response is found to be inverted barometer at periods greater than two months. Global averages of tide gauge data, after correcting for the effects of post glacial rebound on individual station records, reveal an increase in sea level over the last 80 years of between 1.1 mm/yr and 1.9 mm/yr.

Trupin, A.; Wahr, J.

1990-01-01

369

Highlights of Space Weather Services/Capabilities at NASA/GSFC Space Weather Center  

NASA Technical Reports Server (NTRS)

The importance of space weather has been recognized world-wide. Our society depends increasingly on technological infrastructure, including the power grid as well as satellites used for communication and navigation. Such technologies, however, are vulnerable to space weather effects caused by the Sun's variability. NASA GSFC's Space Weather Center (SWC) (http://science.gsfc.nasa.gov//674/swx services/swx services.html) has developed space weather products/capabilities/services that not only respond to NASA's needs but also address broader interests by leveraging the latest scientific research results and state-of-the-art models hosted at the Community Coordinated Modeling Center (CCMC: http://ccmc.gsfc.nasa.gov). By combining forefront space weather science and models, employing an innovative and configurable dissemination system (iSWA.gsfc.nasa.gov), taking advantage of scientific expertise both in-house and from the broader community as well as fostering and actively participating in multilateral collaborations both nationally and internationally, NASA/GSFC space weather Center, as a sibling organization to CCMC, is poised to address NASA's space weather needs (and needs of various partners) and to help enhancing space weather forecasting capabilities collaboratively. With a large number of state-of-the-art physics-based models running in real-time covering the whole space weather domain, it offers predictive capabilities and a comprehensive view of space weather events throughout the solar system. In this paper, we will provide some highlights of our service products/capabilities. In particular, we will take the 23 January and the 27 January space weather events as examples to illustrate how we can use the iSWA system to track them in the interplanetary space and forecast their impacts.

Fok, Mei-Ching; Zheng, Yihua; Hesse, Michael; Kuznetsova, Maria; Pulkkinen, Antti; Taktakishvili, Aleksandre; Mays, Leila; Chulaki, Anna; Lee, Hyesook

2012-01-01

370

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

371

N-way partial least squares with variable importance in projection combined to GC?×?GC-TOFMS as a reliable tool for toxicity identification of fresh and weathered crude oils.  

PubMed

In this study, N-way partial least squares (NPLS) is proposed to correlate comprehensive two-dimensional gas chromatography-time of flight mass spectrometry (GC?×?GC-TOFMS) data of different aromatic oil fractions (fresh and weathered) to their toxicity values. Before NPLS modeling, since drift and wander of baseline interfere with information of sought analytes in GC?×?GC-TOFMS data, a novel method called two-dimensional asymmetric least squares is thus developed for comprehensive correction of the baseline contributions in both chromatographic dimensions. The algorithm is termed comprehensive because it functions to correct the entire chromatogram in both dimensions and it preserves the separation information in both dimensions. In this method, a smoother is combined with asymmetric weighting of deviations from the (smooth) trend to get an effective baseline estimator in both chromatographic dimensions. After baseline correction, the NPLS model was calibrated with 20 oil fractions and evaluated by leave-one-out cross-validation. The number of latent variables was chosen on the basis of minimum root mean squares error of cross validation (RMSECV), and it was 7 (RMSECV?=?0.073). The developed NPLS model was able to accurately predict the toxicity effects in the five oil fractions as prediction sets which were independent of 20 oil fractions in calibration set (RMSEP?=?0.0099 and REP?=?11.38 %). Finally, the newly developed n-way variable importance in projection (NVIP) was used for identification of the most influential chemical components on the toxicity values of different oil fractions. According to the high NVIP values in both chromatographic dimensions and their corresponding mass spectra, alkyl substituted three- and four-ring aromatic hydrocarbons were identified. It is concluded that multivariate chemometric methods (e.g., NPLS) combined to non-target analysis using GC?×?GC-TOFMS is a viable strategy to be used for analytical identification in fuel oil studies, with a potential to reduce the number of fractionation steps needed to obtain necessary chromatographic and mass spectral information. PMID:25173867

Mostafapour, Sara; Parastar, Hadi

2015-01-01

372

Evidence for nonmigrating tides produced by the interaction between tides and stationary planetary waves in the stratosphere and lower mesosphere  

NASA Astrophysics Data System (ADS)

this work, 11 years (2002-2012) of Thermosphere, Ionosphere, Mesosphere Energetics, and Dynamics/Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) global temperature data are used to study the nonlinear interaction between stationary planetary waves (SPWs) and tides in the stratosphere and mesosphere. The holistic behavior of the nonlinear interactions between all SPWs and tides is analyzed from the point of view of energetics. The results indicate that the intensities of nonmigrating diurnal, semidiurnal, terdiurnal, and 6 h tides are strongest during winter and almost vanish during summer, synchronous with SPW activity. Temporal correlations between the SPWs and nonmigrating tides for these four tidal components are strong in the region poleward of 20° and below about 80 km. In the tropics, where the SPWs are very weak in all seasons, the correlations are small. Bispectral analysis between triads of waves and tides shows which particular interactions are likely to be responsible for the generation of the nonmigrating tides that are largest in the midlatitude stratosphere. Based on the more limited SABER observations at high latitudes, the correlations there are similar to those in midlatitudes during spring, summer, and autumn; there are no high-latitude observations by SABER in winter. These results show that nonlinear interactions between SPWs and tides in the stratosphere and the lower mesosphere may be an important source of the nonmigrating tides that then propagate into the upper mesosphere and lower thermosphere.

Xu, Jiyao; Smith, A. K.; Liu, Mohan; Liu, Xiao; Gao, Hong; Jiang, Gouying; Yuan, Wei

2014-01-01

373

Sunspots, Space Weather and Climate  

NASA Technical Reports Server (NTRS)

Four hundred years ago this year the telescope was first used for astronomical observations. Within a year, Galileo in Italy and Harriot in England reported seeing spots on the surface of the Sun. Yet, it took over 230 years of observations before a Swiss amateur astronomer noticed that the sunspots increased and decreased in number over a period of about 11 years. Within 15 years of this discovery of the sunspot cycle astronomers made the first observations of a flare on the surface of the Sun. In the 150 years since that discovery we have learned much about sunspots, the sunspot cycle, and the Sun s explosive events - solar flares, prominence eruptions and coronal mass ejections that usually accompany the sunspots. These events produce what is called Space Weather. The conditions in space are dramatically affected by these events. Space Weather can damage our satellites, harm our astronauts, and affect our lives here on the surface of planet Earth. Long term changes in the sunspot cycle have been linked to changes in our climate as well. In this public lecture I will give an introduction to sunspots, the sunspot cycle, space weather, and the possible impact of solar variability on our climate.

Hathaway, David H.

2009-01-01

374

Health Issues and Space Weather  

NASA Astrophysics Data System (ADS)

The possibility that solar activity and variations in the Earth's magnetic field may affect human health has been debated for many decades but is still a "scientific topic" in its infancy. By learning whether and, if so, how much the Earth's space weather can influence the daily health of people will be of practical importance. Knowing whether human genetics, include regulating factors that take into account fluctuations of the Earth's magnetic field and solar disturbances, indeed exist will also benefit future interplanetary space travelers. Because the atmospheres on other planets are different from ours, as well as their interaction with the space environment, one may ask whether we are equipped with the genetics necessary to take this variability into account. The goal of this presentation is to define what is meant by space weather as a health risk and identify the long-term socio-economic effects on society that such health risks would have. Identifying the physical links between space weather sources and different effects on human health, as well as the parameters (direct and indirect) to be monitored, the potential for such a cross-disciplinary study will be invaluable, for scientists and medical doctors, as well as for engineers.

Crosby, N.

2009-04-01

375

Sensitivity of building cooling loads to future weather predictions  

Microsoft Academic Search

The interaction and the relationship between global warming and thermal performance buildings are dynamic in nature. In order to model and understand this behaviour, different approaches, including that of keeping the weather variable unchanged, the morphing approach and the diurnal modelling method, have been used to project and generate future weather data. Among these approaches, various assumptions of change in

Lisa Guan

2011-01-01

376

Adaptive Grids for Weather and Climate Models C. Jablonowski  

E-print Network

Adaptive Grids for Weather and Climate Models C. Jablonowski National Center for Atmospheric.: ADAPTIVE GRIDS FOR WEATHER AND CLIMATE MODELS two grids coincide. Other variable-resolution models. Oehmke2, Q. F. Stout2, B. van Leer3 University of Michigan, Ann Arbor, USA ABSTRACT An adaptive grid

Stout, Quentin F.

377

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

378

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.

379

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

380

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

381

Sedimentary Rocks and Weathering  

NSDL National Science Digital Library

This site contains 42 questions on the topic of sedimentary rocks and weathering including clast sizes, depositional environments, and products of weathering. This is part of the Principles of Earth Science course at the University of South Dakota. Users select an answer and are provided immediate feedback.

Heaton, Timothy

382

Home Weatherization Visit  

ScienceCinema

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

2013-05-29

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

Weather Fundamentals: Wind. [Videotape].  

ERIC Educational Resources Information Center

The videos in this educational series, for grades 4-7, help students understand the science behind weather phenomena through dramatic live-action footage, vivid animated graphics, detailed weather maps, and hands-on experiments. This episode (23 minutes) describes the roles of the sun, temperature, and air pressure in creating the incredible power…

1998

385

Weather Fundamentals: Clouds. [Videotape].  

ERIC Educational Resources Information Center

The videos in this educational series, for grades 4-7, help students understand the science behind weather phenomena through dramatic live-action footage, vivid animated graphics, detailed weather maps, and hands-on experiments. This episode (23 minutes) discusses how clouds form, the different types of clouds, and the important role they play in…

1998

386

Uncertain weather, uncertain climate  

E-print Network

of the Speckled Band" "Good-morning, madam," said Holmes cheerily. "My name is Sherlock Holmes. #12;222b Baker sit on the left-hand side of the driver." #12;Holmes' calculation D. Nychka Uncertain weather Maximize over vehicle #12;D. Nychka Uncertain weather, uncertain climate 8 Holmes' conclusion ­ the highest

Nychka, Douglas

387

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

388

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).

389

Preprint, 15th Conf. on Numerical Weather Prediction and 19th Conf. on Weather Analysis and Forecasting  

E-print Network

Preprint, 15th Conf. on Numerical Weather Prediction and 19th Conf. on Weather Analysis Center for Analysis and Prediction of Storms and 2 School of Meteorology, University of Oklahoma, Norman is that observations that differ from the analysis variables can be directly analyzed as long as they can be expressed

Xue, Ming

390

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

391

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

392

Wave and tide powered generation apparatus  

SciTech Connect

A wave and tide powered generation apparatus includes a frame which is fixed relative to the varying level of the body of water, and includes a float operably associated with the frame for movement in response to the varying level of the body of water. A rotatable drum is attached to the float and has a drive line with a middle portion wrapped around the rotatable drum. Upper and lower ends of the drive line are attached to upper and lower portions of the frame. Movement of the float upward or downward relative to the frame causes the rotatable drum to be rotated due to its engagement with the drive line. A power transfer apparatus transmits the rotary motion of the drum to a generator.

Suggs, L. F.

1985-09-03

393

Mars mesosphere and thermosphere coupling - Semidiurnal tides  

NASA Astrophysics Data System (ADS)

The Mars thermospheric general circulation model (MTGCM) is modified to examine the impact of a prescribed semidiurnal tidal wave upon Martian thermospheric fields corresponding to near solar minimum (Mariner 9) and solar maximum (Mariner 6-7) observational periods. The effects of upward propagating tides are introduced into the Mars Thermospheric General circulation Model (MTGCM) by appropriately specifying its lower boundary condition according to classical tidal theory. Estimates of the amplitude and phase of the likely dominant semidiurnal (2,2) mode at the mesopause (about 100 km) are specified for a range of possible lower atmosphere dust conditions. MTGCM simulations contrasting tidally driven fields with solar-only forced ones exhibit a dramatic change in the horizontal and vertical wind patterns, whereby the global temperature and oxygen distributions are also modified significantly.

Bougher, S. W.; Fesen, C. G.; Ridley, E. C.; Zurek, R. W.

1993-02-01

394

Gastrointestinal Emergency Room Admissions and Florida Red Tide Blooms  

PubMed Central

Human exposure to brevetoxins during Florida red tide blooms formed by Karenia brevis has been documented to cause acute gastrointestinal, neurologic, and respiratory health effects.. Traditionally, the routes of brevetoxin exposure have been through the consumption of contaminated bivalve shellfish and the inhalation of contaminated aerosols. However, recent studies using more sensitive methods have demonstrated the presence of brevetoxins in many components of the aquatic food web which may indicate potential alternative routes for human exposure. This study examined whether the presence of a Florida red tide bloom affected the rates of admission for a gastrointestinal diagnosis to a hospital emergency room in Sarasota, FL. The rates of gastrointestinal diagnoses admissions were compared for a 3-month time period in 2001 when Florida red tide bloom was present onshore to the same 3-month period in 2002 when no Florida red tide bloom occurred. A significant 40% increase in the total number of gastrointestinal emergency room admissions for the Florida red tide bloom period was found compared to the non red tide period. These results suggest that the healthcare community may experience a significant and unrecognized impact from patients needing emergency medical care for gastrointestinal illnesses during Florida red tide blooms. Thus, additional studies characterizing the potential sources of exposure to the toxins, as well as the dose/effect relationship of brevetoxin exposure, should be undertaken. PMID:20161425

Kirkpatrick, Barbara; Bean, Judy A; Fleming, Lora E; Kirkpatrick, Gary; Grief, Lynne; Nierenberg, Kate; Reich, Andrew; Watkins, Sharon; Naar, Jerome

2009-01-01

395

Spectroscopic analysis of global tide gauge sea level data  

NASA Technical Reports Server (NTRS)

Yearly and monthly global tide-gage sea-level data are fitted to numerically generated tidal data in order to search for the 18.6-yr lunar nodal tide and 14-month pole tide. Both of these tides are clearly evident, with amplitudes and phases that are consistent with a global equilibrium response. The ocean's response to atmospheric pressure is studied with the least-squares fit technique. Consideration is given to the global rise in sea level, the effects of postglacial rebound, and the possible causes of the enhanced pole tides in the North Sea, the Baltic Sea, and the Gulf of Bothnia. The results support O'Connor's (1986) suggestion that the enhanced pole tide in these regions is due to meteorological forcing rather than a basin-scale resonance. Also, the global average of the tide-gage data show an increase in sea level over tha last 80 yr of between 1.1 and 1.9 mm/yr.

Trupin, A.; Wahr, J.

1990-01-01

396

The shaping of continental slopes by internal tides  

USGS Publications Warehouse

The angles of energy propagation of semidiurnal internal tides may determine the average gradient of continental slopes in ocean basins (???2 to 4 degrees). Intensification of near-bottom water velocities and bottom shear stresses caused by reflection of semi-diurnal internal tides affects sedimentation patterns and bottom gradients, as indicated by recent studies of continental slopes off northern California and New Jersey. Estimates of bottom shear velocities caused by semi-diurnal internal tides are high enough to inhibit deposition of fine-grained sediment onto the slopes.

Cacchione, D.A.; Pratson, Lincoln F.; Ogston, A.S.

2002-01-01

397

The self-consistent dynamic pole tide in global oceans  

NASA Technical Reports Server (NTRS)

The dynamic pole tide is characterized in a self-consistent manner by means of introducing a single nondifferential matrix equation compatible with the Liouville equation, modelling the ocean as global and of uniform depth. The deviations of the theory from the realistic ocean, associated with the nonglobality of the latter, are also given consideration, with an inference that in realistic oceans long-period modes of resonances would be increasingly likely to exist. The analysis of the nature of the pole tide and its effects on the Chandler wobble indicate that departures of the pole tide from the equilibrium may indeed be minimal.

Dickman, S. R.

1985-01-01

398

Case Study 1 Red Tide Detection in the Eastern Gulf of Mexico  

E-print Network

Case Study 1 Red Tide Detection in the Eastern Gulf of Mexico Using MODIS Imagery Chuanmin Hu1.1 Background Many of the red tides (i.e., harmful algal blooms or HABs) in the eastern Gulf of Mexico (GOM) (24 (Dierssen et al., 2006), they are commonly referred to as red tides. In the eastern GOM, red tides occur

Meyers, Steven D.

399

Modeling the diurnal tide with dissipation derived from UARS/HRDI measurements  

E-print Network

Modeling the diurnal tide with dissipation derived from UARS/HRDI measurements M. A. Geller1 , V. A UARS/HRDI observations in a recently published diurnal-tide model. These model structures compare quite the annual variation of the diurnal tide. 1 Introduction The diurnal tide in the mesosphere

Paris-Sud XI, Université de

400

Will global warming affect males and females differently? FHL Tide Bites #4 Dec. 2013  

E-print Network

Will global warming affect males and females differently? FHL Tide Bites #4 Dec. 2013 Life on a rocky shore is challenging. With each passing tide, the animals and plants of this land-sea interface that her focal snails eat in rhythm with the tides, feeding in hoards when low tide exposure is at night

Carrington, Emily

401

Singularly perturbed degenerated parabolic equations and application to seabed morphodynamics in tided environment  

E-print Network

in tided environment Ibrahima FAYE Emmanuel FRENOD Diaraf SECK May 12, 2010 Abstract In this paper we build 2 within tide-influenced environment is essentially not efficient. The reason why is that tide are present in strong tide region (English Channel, Celtic Sea, Irish Sea, North Sea, etc.) the setting out

Brest, Université de

402

Tide Model Accuracy in the Amundsen Sea, Antarctica, from InSAR Observations of Ice  

E-print Network

Tide Model Accuracy in the Amundsen Sea, Antarctica, from InSAR Observations of Ice Shelf Motion.mcmillan@leeds.ac.uk. Abstract Tide Model Evaluation This study assesses the accuracy of tide model predictions in the Amundsen Sea Sector of West Antarctica. · Tide model accuracy in this remote region is poorly constrained, yet

403

Modeling tides in Monterey Bay, California Xiaochun Wang a,b  

E-print Network

Modeling tides in Monterey Bay, California Xiaochun Wang a,b , Yi Chao a,Ã?, Changming Dong c , John October 2008 Keywords: Monterey Bay Barotropic tides Baroclinic tides Modeling Energy flux High-frequency radar a b s t r a c t In the process of developing a tide-permitting coastal ocean forecasting system

Dong, Changming "Charles"

404

Long-Range Propagation of the Semidiurnal Internal Tide from the Hawaiian Ridge ZHONGXIANG ZHAO  

E-print Network

Long-Range Propagation of the Semidiurnal Internal Tide from the Hawaiian Ridge ZHONGXIANG ZHAO internal tide from French Frigate Shoals (FFS), Hawaii, is studied with an array of six simultaneous tide's coherent portion. Together these two approaches provide a unique view of the internal tide

MacKinnon, Jennifer

405

Amphipods and isopods in the rocky intertidal: dispersal and movements during high tide  

E-print Network

Amphipods and isopods in the rocky intertidal: dispersal and movements during high tide Received patterns is, however, almost exclusively based on surveys made during low tide, when many animals Iceland, both by traditional sampling at low tide as well as by sampling during high tide

Agnarsson, Ingi

406

An inter-comparison of ocean tide loading estimates for Antarctica from models and GPS  

Microsoft Academic Search

We present ocean tide loading (OTL) estimates for Antarctica based on several numerical tide models and direct estimates from GPS observations. Accurate estimates of the ocean tides in the Antarctic region are difficult to obtain from numerical ocean tide models due to the lack of bathymetric information and direct tidal observations in the sub ice shelf regions in particular. Consequently,

M. King; P. Clarke; C. Allinson

2003-01-01

407

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.

408

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.

2014-09-14

409

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.

410

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

411

Weather and Climate  

NSDL National Science Digital Library

This unit introduces younger students to the concepts of weather and climate. Topics include the structure of the atmosphere, the definitions of weather and climate, and temperature and how it is measured. There are also discussions of heat transfers (radiation, conduction, convection), air pressure, wind, and the Coriolis effect. Other topics include types of storms, larger-scale weather systems such as pressure systems and fronts, and factors (insolation, land-sea breezes, orographic effect) that influence the climate in a given region. A vocabulary list and downloadable, printable student worksheets are provided.

Medina, Philip

412

Extreme Weather Sourcebook 2001  

NSDL National Science Digital Library

Originally reviewed in the February 26, 1999 Scout Report, the latest version of the National Center for Atmospheric Research (NCAR) Extreme Weather Sourcebook offers easy access to updated data on the economic damage from hurricanes, floods, and tornadoes in the United States and its territories. Time spans for each type of extreme weather vary, with hurricane data covering 1900-99, tornadoes 1950-99, floods 1955-1999, and lightning 1959-1994; however, all damage data are reported in constant 1999 dollars to simplify comparisons. The data are offered by weather event and state by rank or alphabetically.

2001-01-01

413

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.

414

Building a Weather-Ready Nation Winter Weather Safety  

E-print Network

-Ready Nation Flooding Winter Weather Safety www.weather.gov · Flooding is possible due to snowmelt, ice jams and coastal storms such as Nor'easters. · Ice jams are common during the winter. · As ice moves downstream www.weather.gov · Snow/Ice · Blizzards · Flooding · Cold Temperatures #12;Building a Weather

415

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

416

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

417

Riser tensioning wave and tide compensating system for a floating platform  

SciTech Connect

A riser tensioner cylinder is provided with a hollow piston rod which forms a second cylinder in which a ram is reciprocated. The free end of the ram is connected to a link which in turn is connected to the end of the riser for providing tension on the riser. The ram reciprocates in the second cylinder under constant pressure to compensate for wave action on the floating platform and the second cylinder is automatically positioned within the first cylinder for adjustment for tide, vessel offset or other infrequent but variable factors.

Heeres, C.J.; Larsen, C.H.

1980-09-16

418

Response of Upward Propagating Tides to Varying Solar Activity Levels (Invited)  

NASA Astrophysics Data System (ADS)

Upward propagating tides are more readily dissipated in a hot thermosphere and therefore react strongly to varying solar activity levels. Consequently, the relative importance of tidal wave coupling from below for understanding ionosphere-thermosphere variability will change from solar minimum to solar maximum. The paper presents the response of tidal dynamics in the thermosphere to the solar cycle using SABER, TIDI and CHAMP observations, supported by empirical tidal modeling. Tidal variations in other parameters important to aeronomy, such as plasma density and infrared cooling, are also discussed.

Oberheide, J.

2013-12-01

419

Online coupled chemical weather forecasting based on HIRLAM - overview and prospective of Enviro-HIRLAM  

Microsoft Academic Search

Chemical weather is a field of increasing popularity and several institutes, such as Environment Canada and NOAA, currently forecast both chemical and meteorological weather. Following a definition (Lawrence et al., 2005), chemical weather may be given as local, regional and global distributions of trace gases and aerosols with corresponding variability ranging from minutes to days. Two modeling paradigms exist for

Ulrik Smith Korsholm; Alexander Baklanov; Allan Gross; Alexander Mahura; Bent Hansen Sass; Eigil Kaas

2008-01-01

420

Monitoring Sea Level by Tide Gauges and GPS at Barcelona and Estartit Harbours  

NASA Astrophysics Data System (ADS)

Sea level is an environmental variable which is widely recognised as being important in many scientific disciplines as a control parameter for coastal dynamical processes or climate processes in the coupled atmosphere-ocean systems, as well as engineering applications. A major source of sea-level data are the national networks of coastal tide gauges, in Spain belonging to different institutions as the Instituto Geográfico Nacional (IGN), Puertos del Estado (PE), Instituto Hidrográfico de la Marina (IHM), etc. The tide gauge of l'Estartit is a traditional floating gauge placed 21 years ago and has an accuracy of ± 2 mm. Since 1996, l'Estartit tide gauge has been co-located with geodetic techniques (GPS measurements of XU, Utilitary Network, and XdA, Levelling Network,) and it is tied to the SPGIC (Integrated Geodetic Positioning System of Catalonia) project of the Cartographic Institute of Catalunya (ICC). In 2006, due to the work for the expansion of the harbour, the tide gauge had to be moved. Before the work started, appropiate GPS measurements were carried out in order to ensure the connection of the tide gauge data. During October 2006 and May 2008, the tide gauge was inactive and it has been moved on to a new location inside the harbour. In June 2008, new GPS and levelling measures have been done in order to tie the new location into SPGIC project and to co-locate old data respect the new one. Although l'Estartit does not have a GPS permanent station, it is possible to build a virtual one from the service "CATNET web" of the ICC. "CATNET web" is a data distribution system of a virtual GPS permanent station via web. From the coordinates where you want to place the virtual station, the time interval and the measurement rate, the system generates a RINEX file under the requested conditions. At Barcelona harbour there is one MIROS radar tide gauge belonging to Puertos del Estado (Spanish Harbours). It is placed at the dock 140 of the ENAGAS Building.The radar sensor is over the water surface, on a L-shaped structure which elevates it a few meters above the quay shelf. 1-min data are transmitted to the ENAGAS Control Center by cable and then sent each 1 min to Puertos del Estado by e-mail.This sensor also measures agitation and sends wave parameters each 20 min. A provisional tide gauge bench mark has been defined while the levelling has being done. There is a GPS station Leica Geosystems GRX1200 GG Pro and antenna 1202. Bathymetric campaigns inside the harbour have been made. The presentation is directed to the description of the actual situation of the geodetic infrastructure of Barcelona and l'Estartit sites for sea level determination and contribution to regional sea level rise.

Martinez Benjamin, J. J.; Gili, J.; Lopez, R.; Tapia, A.; Bosch, E.; Perez, B.; Pros, F.

2012-04-01

421

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

422

Tide- and wind-driven flushing of Boston Harbor, Massachusetts  

USGS Publications Warehouse

The flushing of Boston Harbor, a shallow, tidally dominated embayment with little fresh water input, is investigated using a depth-averaged model. The modeled tidal currents exhibit strong spatial variability and ebb/flood asymmetry due to complex topography and coastline geometry and were verified by shipboard acoustic Doppler current profiler measurements. At the inlets to the harbor, the asymmetry between flood and ebb gives rise to a net exchange of water, which acts over successive tidal cycles to flush the harbor. The flushing is examined by tracking water that starts out in Boston Harbor for 40 M2 tidal cycles. The tidal flushing is very efficient at mixing water in the vicinity of the inlets over several tidal cycles, but efficiency decreases with time as ``tidal mixing regions'' form on either side of the harbor inlets. When wind forcing is included, the wind-driven currents act to flush the tidal mixing regions, giving rise to more efficient flushing. The exception is when the wind is from the southwest, which confines the jet-like ebb flow from the harbor and therefore reduces the flushing efficiency. In general, flushing is shown to be a two-step process: (1) rapid exchange due to tides over a large region in the vicinity of the harbor inlets and (2) flushing of this region by wind-driven flow. The model also demonstrates that flushing is not uniform over the entire harbor but occurs rapidly in the deep tidal channels and slowly in the regions of weak tidal currents around the harbor periphery. Although the depth-averaged approach to flushing is appropriate over most of the harbor due to the harbor's shallow depth and broad depth distribution, the lack of bathymetric variability and the presence of locally important density driven currents in the Boston Inner Harbor indicates that flushing of this localized area must be approached with a three-dimensional model.

Signell, Richard

1992-01-01

423

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

424

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

425

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

426

Extreme Weather Sourcebook: Tornadoes  

NSDL National Science Digital Library

The Extreme Weather Sourcebook is a database maintained by the Societal Impacts Program (SIP) at NCAR of statistics on extreme weather events. The Sourcebook is intended as a resource for researchers, policy makers, the media, and the general public, among other users. This page from the Sourcebook showcases data on tornado damages as total losses for the years 1950-2009 in the United States.

University Consortium for Atmospheric Research (UCAR)

427

4. View of Sterling Creek Marsh at low tide showing ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. View of Sterling Creek Marsh at low tide showing rubble at the entrance of the dam/bridge looking east - Richmond Hill Plantation, Sterling Creek Marsh, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

428

3. View of Sterling Creek Marsh at low tide showing ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. View of Sterling Creek Marsh at low tide showing rubble at the entrance of dam/bridge looking southwest - Richmond Hill Plantation, Sterling Creek Marsh, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

429

Energy Dissipation by Tides and Librations in Synchronous Satellites  

NASA Technical Reports Server (NTRS)

Energy dissipation associated with physical librations of large synchronous satellites may be important for maintaining internal fluid layers. Depending on the depth and viscosity of the fluid layer, viscous heating from librations may exceeed that from tides.

Bills, B. G.; Ray, R. D.

2000-01-01

430

Atmospheric Tides in the Latest Generation of Climate Models  

E-print Network

For atmospheric tides driven by solar heating, the database of climate model output used in the most recent assessment report of the Intergovernmental Panel on Climate Change (IPCC) confirms and extends the authors’ earlier ...

Covey, Curt

431

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

432

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

433

Technical note: Age of diurnal tide in the World Oceans  

Microsoft Academic Search

Updated maps showing the age of the diurnal tide in the Atlantic, Pacific, Indian, and Arctic oceans are given. In addition diagrams depicting the O1\\/K1 amplitude ratios for the world oceans are included.

T. S. Murty

1989-01-01

434

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

435

Seasonal variations in Pluto's atmospheric tides  

NASA Astrophysics Data System (ADS)

Pluto's tenuous atmosphere exhibits remarkable seasonal change as a result of the planet's substantial obliquity and highly eccentric orbit. Over the past two decades, occultations have revealed that the atmospheric pressure on Pluto has increased substantially, perhaps by a factor as large as 2 to 4, as the planet has moved from equinox towards solstice conditions. These data have also shown variations in the strength of the dynamical activity in the atmosphere, as revealed by the varying abundance and amplitude of spikes in the occultation light curves resulting from refractive focussing by atmospheric waves. Toigo et al. (Toigo et al. [2010]. Icarus, 208, 402-411) explored the possibility that these waves are caused by solar-induced sublimation and diurnal deposition from N2 frost patches, driven by weak vertical winds resulting from the rising and sinking gas as it is released from or deposited onto the surface. Here, we extend this model to account explicitly for seasonal variations in average insolation and for the significant damping of vertical wave propagation by kinematic viscosity and thermal diffusivity (Hubbard et al. [2009]. Icarus, 204, 284-289). Damping is extremely effective in suppressing vertical propagation of waves with vertical wavelengths of a few kilometers or less, and the dominant surviving tidal modes have characteristic vertical wavelengths ? ? 10-13 km . We estimate the expected strength and regional characteristics of atmospheric tides over the course of Pluto's orbit for a variety of assumed spatial distributions of surface frost and atmospheric surface pressure. We compute the predicted strength of tide-induced wave activity based on the actual frost distribution observed on Pluto from Hubble Space Telescope (HST) observations (Stern et al. [1997]. Astron. J., 113, 827; Buie et al. [2010]. Astron. J., 139, 1128-1143), and compare the results to calculations for volatile transport models of Young (Young [2013]. Astrophys. J., 766, L22) and Hansen et al. (Hansen et al. [2015]. Icarus, 246, 183-191). We develop simple scaling rules to estimate the variation of the strength of tidal activity with surface pressure PS and solar declination ?? , and show that the maximum expected temperature perturbation at an atmospheric pressure of P = 0.1 Pa scales as dTmax ? cos?? /?{PS } . Wave activity is strongest in the near-equatorial region (latitude | ? | ? 30 °), being only weakly dependent on the detailed frost distribution. Using a 3-D time-dependent geometric optics ray-tracing code, we compute model light curves for the geometric circumstances of three high-SNR occultations (2002 August 21, 2006 June 12, and 2012 July 18), taking into account the detailed three-dimensional characteristics of the tides as different regions of the atmosphere are probed over the course of each occultation chord. We compare the strength and abundance of the scintillations in the models with those seen in the data, using both the HST frost maps and the volatile transport model predictions. The striking asymmetries in the strengths of spikes between ingress and egress seen in some events are reproduced in the tidal model simulations, due primarily to the latitudes probed during the occultation: occultations at high northern or southern latitudes uniformly have much weaker wave activity than more equatorial events. A surface pressure range of PS = 1-2 Pa provides the best match between models and observations. With the impending arrival of the New Horizons spacecraft at Pluto in 2015, we predict that wave activity in the upper atmosphere will be strongest at equatorial regions, and controlled in amplitude primarily by the surface pressure and damping effects, rather than by the detailed frost distribution. If Pluto's atmosphere begins to collapse in the coming decades, we expect that future stellar occultations will provide evidence for greatly enhanced atmospheric wave activity.

French, Richard G.; Toigo, Anthony D.; Gierasch, Peter J.; Hansen, Candice J.; Young, Leslie A.; Sicardy, Bruno; Dias-Oliveira, Alex; Guzewich, Scott D.

2015-01-01

436

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

437

TIDE Observations of Cusp and Cleft Multiple Ion Populations  

NASA Technical Reports Server (NTRS)

The southern pole pass of Polar/TIDe at 5000 km allows a study of the distributions of the cusp and cleft. We discuss observations of TIDE (Thermal Ion Dynamics Experiment) as it passes the southern pole on March 29, 1999. A mixture of several cold outflowing ions (0.3-10 eV) are measured simultaneously with magnetospheric precipitation (greater than 100 eV). We will show a study of these multiple plasma distributions, their source, and their interaction.

Coffey, Victoria N.; Chandler, Michael O.; Moore, Thomas E.

2000-01-01

438

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

439

2012 Severe Weather Awareness Guide  

E-print Network

Florida's 2012 Severe Weather Awareness Guide 2012 Severe Weather Awareness Guide F L O R I D A D I of Emergency Management #12;Florida's Severe Weather Awareness Guide 2 Florida is affected by many natural. That is why I am proud to present the 2012 Severe Weather Awareness Guide. By reading this guide you can learn

Meyers, Steven D.

440

Lunar and Solar Torques on the Oceanic Tides  

NASA Technical Reports Server (NTRS)

A general framework for calculating lunar and solar torques on the oceanic tides is developed in terms of harmonic constituents. Axial torques and their associated angular momentum and earth-rotation variations are deduced from recent satellite-altimeter and satellite-tracking tide solutions. Torques on the prograde components of the tide produce the familiar secular braking of the rotation rate. The estimated secular acceleration is approximately -1300 sec/century(sup 2) (less 4% after including atmospheric tides); the implied rate of change in the length of day is 2.28 milliseconds/century. Torques on the retrograde components of the tide produce periodic rotation variations at twice the tidal frequency. Interaction torques, e.g. solar torques on lunar tides, generate a large suite of rotation-rate variations at sums and differences of the original tidal frequencies. These are estimated for periods from 18.6 years to quarter-diurnal. At subdaily periods the angular momentum variations are 5 to 6 orders of magnitude smaller than the variations caused by ocean tidal currents.

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

1998-01-01

441

Fortnightly Earth Rotation, Ocean Tides, and Mantle Anelasticity  

NASA Technical Reports Server (NTRS)

Sustained accurate measurements of earth rotation are one of the prime goals of Global Geodetic Observing System (GGOS). We here concentrate on the fortnightly (Mf) tidal component of earth-rotation data to obtain new results concerning anelasticity of the mantle at this period. The study comprises three parts: (1) a new determination of the Mf component of polar motion and length-of-day from a multi-decade time series of 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. Our model of the Mf ocean tide assimilates more than fourteen years of altimeter data from the Topex/Poseidon and Jason-1 satellites. 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 length-of-day caused by mantle anelasticity. The inferred effective tidal 0 of the anelastic body tide is 90 and is in line with a omega-alpha frequency dependence with alpha in the range 0.2--0.3.

Ray, Richard D.; Egbert, Gary D.

2011-01-01

442

Fortnightly Ocean Tides, Earth Rotation, and Mantle Anelasticity  

NASA Technical Reports Server (NTRS)

The fortnightly Mf ocean tide is the largest of the long-period tides (periods between 1 week and 18.6 years), but Mf is still very small, generally 2 cm or less. All long-period tides are thought to be near equilibrium with the astronomical tidal potential, with an almost pure zonal structure. However, several lines of evidence point to Mf having a significant dynamic response to forcing. We use a combination of numerical modeling, satellite altimetry, and observations of polar motion to determine the Mf ocean tide and to place constraints on certain global properties, such as angular momentum. Polar motion provides the only constraints on Mf tidal currents. With a model of the Mf ocean tide in hand, we use it to remove the effects of the ocean from estimates of fortnightly variations in length-of-day. The latter is dominated by the earth's body tide, but a small residual allows us to place new constraints on the anelasticity of the earth's mantle. The result gives the first experimental confirmation of theoretical predictions made by Wahr and Bergen in 1986.

Ray, Richard; Egbert, Gary

2012-01-01

443

Geodynamic Effects of Ocean Tides: Progress and Problems  

NASA Technical Reports Server (NTRS)

Satellite altimetry, particularly Topex/Poseidon, has markedly improved our knowledge of global tides, thereby allowing significant progress on some longstanding problems in geodynamics. This paper reviews some of that progress. Emphasis is given to global-scale problems, particularly those falling within the mandate of the new IERS Special Bureau for Tides: angular momentum, gravitational field, geocenter motion. For this discussion I use primarily the new ocean tide solutions GOT99.2, CSR4.0, and TPXO.4 (for which G. Egbert has computed inverse-theoretic error estimates), and I concentrate on new results in angular momentum and gravity and their solid-earth implications. One example is a new estimate of the effective tidal Q at the M_2 frequency, based on combining these ocean models with tidal estimates from satellite laser ranging. Three especially intractable problems are also addressed: (1) determining long-period tides in the Arctic [large unknown effect on the inertia tensor, particularly for Mf]; (2) determining the global psi_l tide [large unknown effect on interpretations of gravimetry for the near-diurnal free wobble]; and (3) determining radiational tides [large unknown temporal variations at important frequencies]. Problems (2) and (3) are related.

Richard, Ray

1999-01-01

444

Detection and attribution of extreme weather disasters  

NASA Astrophysics Data System (ADS)

Single disasters related to extreme weather events have caused loss and damage on the order of up to tens of billions US dollars over the past years. Recent disasters fueled the debate about whether and to what extent these events are related to climate change. In international climate negotiations disaster loss and damage is now high on the agenda, and related policy mechanisms have been discussed or are being implemented. In view of funding allocation and effective risk reduction strategies detection and attribution to climate change of extreme weather events and disasters is a key issue. Different avenues have so far been taken to address detection and attribution in this context. Physical climate sciences have developed approaches, among others, where variables that are reasonably sampled over climatically relevant time periods and related to the meteorological characteristics of the extreme event are examined. Trends in these variables (e.g. air or sea surface temperatures) are compared between observations and climate simulations with and without anthropogenic forcing. Generally, progress has been made in recent years in attribution of changes in the chance of some single extreme weather events to anthropogenic climate change but there remain important challenges. A different line of research is primarily concerned with losses related to the extreme weather events over time, using disaster databases. A growing consensus is that the increase in asset values and in exposure are main drivers of the strong increase of economic losses over the past several decades, and only a limited number of studies have found trends consistent with expectations from climate change. Here we propose a better integration of existing lines of research in detection and attribution of extreme weather events and disasters by applying a risk framework. Risk is thereby defined as a function of the probability of occurrence of an extreme weather event, and the associated consequences, with consequences being a function of the intensity of the physical weather event, the exposure and value of assets, and vulnerabilities. We have examined selected major extreme events and disasters, including superstorm Sandy in 2012, the Pakistan floods and the heat wave in Russia in 2010, the 2010 floods in Colombia and the 2011 floods in Australia. We systematically analyzed to what extent (anthropogenic) climate change may have contributed to intensity and frequency of the event, along with changes in the other risk variables, to eventually reach a more comprehensive understanding of the relative role of climate change in recent loss and damage of extreme weather events.

Huggel, Christian; Stone, Dáithí; Hansen, Gerrit

2014-05-01

445

Weather and Environmental Hazards at Mass Gatherings  

PubMed Central

Introduction Reviews of mass gathering events have traditionally concentrated on crowd variables that affect the level and type of medical care needed. Weather and environmental hazards at mass gathering events have not been fully researched. This review examines these events and aims to provide future suggestions for event organisers, medical resource planners, and emergency services, including local hospital emergency departments. Methods A review was conducted using computerised data bases: MEDLINE, The Cochrane Library, HMIC and EMBASE, with Google used to widen the search beyond peer-reviewed publications, to identify grey literature. All peer-review literature articles found containing information pertaining to lessons identified from mass gathering disasters due to weather or environmental hazards leading to participant death, injury or illness were analysed and reviewed. Disasters occurring due to crowd variables were not included. These articles were read, analysed, abstracted and summarised. Results 20 articles from literature search were found detailing mass gathering disasters relating directly to weather or environmental hazards from 1988 – 2011, with only 17 cases found within peer-review literature. Two events grey literature from 2011 are due to undergo further inquiry while one article reviews an event originally occurring in 1922. Analysis of cases were categorised in to heat and cold-related events, lightning and storms and disease outbreak. Conclusions Mass gathering events have an enormous potential to place a severe strain on the local health care system, Prior health resource and environmental planning for heat & cold-related illness, lightning & storms, and disease outbreak can advance emergency preparedness and response to potential disasters. Citation: Soomaroo L, Murray V. Weather and Environmental Hazards at Mass Gatherings. PLoS Currents Disasters. 2012 Jul 31 Keywords: Mass Gatherings, Disasters, Sporting Events, Festivals, Concerts, Storm, Lightning, Cyclone, Hot-weather illness, Cold-weather illness, Disease, Public Health, Syndromic Surveillance Abbreviations: ALS – Advance Life support; BLS – Basic Life support; ED – Emergency Department; EMS – Emergency Medical Services; PPR – Patient Presentation Rate PMID:22953242

Soomaroo, Lee; Murray, Virginia

2012-01-01

446

Galactic tide and orbital evolution of comets  

E-print Network

Equation of motion for a comet in the Oort cloud is numerically solved. Orbital evolution of the comet under the action of the gravity of the Sun and the Galaxy is presented for various initial conditions. Oscillations of the Sun with respect to the galactic equatorial plane are taken into account. Real values of physical quantities concerning the gravitational action of the galactic neighbourhood of the Sun are important. The results are compared with currently used more simple models of the galactic tide. It turns out that physically improved models yield results which significantly differ from the results obtained on the basis of the conventional models. E.g., the number of returns of the comets into the inner part of the Solar System are about two times greater than it is in the conventional models. It seems that a comet from the Oort cloud can be a source of the dinosaurs extinction at about 65 Myr ago. A close encounter of a star or an interstellar cloud disturbed a comet of the Oort cloud in the way th...

Komar, L; Pastor, P

2009-01-01

447

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 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.

Jeremy Goodman; Claire Lackner

2008-12-04

448

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

449

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

450

Utilization of Live Localized Weather Information for Sustainable Agriculture  

NASA Astrophysics Data System (ADS)

Authors: Jim Anderson VP, Global Network and Business Development WeatherBug® Professional Jeremy Usher Managing Director, Europe WeatherBug® Professional Localized, real-time weather information is vital for day-to-day agronomic management of all crops. The challenge for agriculture is twofold in that local and timely weather data is not often available for producers and farmers, and it is not integrated into decision-support tools they require. Many of the traditional sources of weather information are not sufficient for agricultural applications because of the long distances between weather stations, meaning the data is not always applicable for on-farm decision making processes. The second constraint with traditional weather information is the timeliness of the data. Most delivery systems are designed on a one-hour time step, whereas many decisions in agriculture are based on minute-by-minute weather conditions. This is especially true for decisions surrounding chemical and fertilizer application and frost events. This presentation will outline how the creation of an agricultural mesonet (weather network) can enable producers and farmers with live, local weather information from weather stations installed in farm/field locations. The live weather information collected from each weather station is integrated into a web-enabled decision support tool, supporting numerous on-farm agronomic activities such as pest management, or dealing with heavy rainfall and frost events. Agronomic models can be used to assess the potential of disease pressure, enhance the farmer's abilities to time pesticide applications, or assess conditions contributing to yield and quality fluctuations. Farmers and industry stakeholders may also view quality-assured historical weather variables at any location. This serves as a record-management tool for viewing previously uncharted agronomic weather events in graph or table form. This set of weather tools is unique and provides a significant enhancement to the agronomic decision-support process. Direct benefits to growers can take the form of increased yield and grade potential, as well as savings in money and time. Pest management strategies become more efficient due to timely and localized disease and pest modelling, and increased efficacy of pest and weed control. Examples from the Canadian Wheat Board (CWB) WeatherFarm weather network will be utilized to illustrate the processes, decision tools and benefits to producers and farmers.

Anderson, J.; Usher, J.

2010-09-01

451

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

452

Monitoring moisture dynamics in weathered, fractured bedrock  

NASA Astrophysics Data System (ADS)

Variably weathered, fractured bedrock underlying hillslopes influences runoff pathways, moisture availability, and slope stability yet direct measurement of moisture dynamics within this zone remains challenging. Established methods for monitoring moisture content in soils are not easily transferrable to fractured rock environments due to inaccessibility and the difficulties associated with the installation and calibration of sensors. At a steep, intensively instrumented hillslope in coastal northern California we explore 7 methods of varying spatial scale and temporal frequency to document moisture dynamics in weathered, fractured argillite bedrock. The forested 4000 m2 catchment is mantled by approximately 50 cm of soil and underlain by a thick weathered bedrock zone which extends to 25 m at the ridge top and thins downslope to a depth of 4 m. The Mediterranean climate at the site is characterized by cool, wet winters and warm, dry summers receiving most of the annual precipitation (1900 mm on average) between October and May. The following measurement methods are employed at the site: 1) downhole neutron moisture logging (CPN 503DR Hydroprobe) in 12 wells, 6-35 m deep 2) time domain reflectometer probes (TDR100, Campbell Scientific) installed in trenches and augured holes of varying backfill material 3) capacitance sensors (SM200, Dynamax, Inc) installed near the surface 4) electrical resistance sensor array systems (ERSAS) installed in augured and backfilled holes, 5) time lapse, non-invasive electrical resistivity tomography, 6) pressure transducers installed in deep wells and 7) laboratory gravimetric measurements of samples collected in augured holes and wells. Our observations highlight how each measurement method individually or collectively contributes to the understanding of moisture dynamics and runoff processes in fractured, weathered bedrock. We found that though backfill material and well casing significantly influence the magnitude of the measured response, using the timing of the response and manufacturer or site specific calibration, allowed us to effectively quantify moisture storage and transport rates in the weathered bedrock. We found that in response to rainfall, all water passes through the soil and weathered bedrock at the site and perches above the fresh bedrock before it travels laterally downslope. The rapid water table response to the first storm events of the season often occurs before the wetting front progresses through the first few meters of the weathered profile. Though shallower weathered bedrock wets and dries annually, deeper portions of the weathered bedrock zone do not show significant seasonal changes in moisture content. As investigations of the critical zone extend deeper, robust techniques for monitoring moisture in weathered bedrock are needed to quantify the significance of rock moisture in hydrologic and geomorphic processes.

Rempe, D. M.; Salve, R.; Oshun, J.; Dietrich, W. E.

2013-12-01

453

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

SciTech Connect

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 cm anywhere in the open oceans. The resulting tidal amplitudes and phases are tabulated on a 1 deg x 1 deg grid system in an atlas of 42 deg x 71 deg overlapping charts covering the whole oceanic globe. A corresponding atlas of global corange and cotidal maps is included to provide the reader with a quick general overview of the major tidal phenomena. The specifying hydrodynamical parameters of the model are listed along with quoted sources of empirical tide data, and significant tidal features are explained and discussed. The diurnal O1 ocean tide is found to resemble closely the diurnal K1 tide and qualitatively also the semidiurnal S2 and M2 tides which were presented in Parts IV, III, and II of this report, respectively (AD's A104 334, A104 333, and A084 694).

Schwiderski, E.W.

1981-05-20

454

Global ocean tides. Part VII. The diurnal principal solar tide (P1), atlas of tidal charts and maps. Final report  

SciTech Connect

In Part I (Schwiderski, 1978a) of this report, 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 solar (P1) ocean tide with a relative accuracy of better than 5 cm anywhere in the open oceans. The resulting tidal amplitudes and phases are tabulated on a 1 deg X 1 deg grid system in an atlas of 42 deg X 71 deg overlapping charts covering the whole oceanic globe. A corresponding atlas of global corange and cotidal maps is included to provide the reader with a quick general overview of the major tidal phenomena. The specifying hydrodynamical parameters of the model are listed along with quoted sources of empirical tide data, and significant tidal features are explained and discussed. As expected, since the periods of the diurnal tides P1 (24.07h) and K1 (23.93 h) differ by only 0.14 h, these two tides resemble very closely each other (compare Part IV). Significant differences occur only in regions of rapid tidal variations. Of course, P1 resembles also the diurnal 01 tide but to a visibly lesser degree (see Part V).

Schwiderski, E.W.

1981-05-01

455

Iron isotopic fractionation during continental weathering  

SciTech Connect

The biological activity on continents and the oxygen content of the atmosphere determine the chemical pathways through which Fe is processed at the Earth's surface. Experiments have shown that the relevant chemical pathways fractionate Fe isotopes. Measurements of soils, streams, and deep-sea clay indicate that the {sup 56}Fe/{sup 54}Fe ratio ({delta}{sup 56}Fe relative to igneous rocks) varies from +1{per_thousand} for weathering residues like soils and clays, to -3{per_thousand} for dissolved Fe in streams. These measurements confirm that weathering processes produce substantial fractionation of Fe isotopes in the modern oxidizing Earth surface environment. The results imply that biologically-mediated processes, which preferentially mobilize light Fe isotopes, are critical to Fe chemistry in weathering environments, and that the {delta}{sup 56}Fe of marine dissolved Fe should be variable and negative. Diagenetic reduction of Fe in marine sediments may also be a significant component of the global Fe isotope cycle. Iron isotopes provide a tracer for the influence of biological activity and oxygen in weathering processes through Earth history. Iron isotopic fractionation during weathering may have been smaller or absent in an oxygen-poor environment such as that of the early Precambrian Earth.

Fantle, Matthew S.; DePaolo, Donald J.

2003-10-01

456

Oceans, Climate and Weather  

NSDL National Science Digital Library

What is the difference between weather and climate? What do the oceans have to do with them? Weather is the day-to-day state of the atmosphere and its short-term (minutes to weeks) variation. Climate is typically described by the regional patterns of seasonal temperature and precipitation over 30 years. The averages of annual temperature, rainfall, cloud cover, and depth of frost penetration are all typical climate-related statistics. The oceans influence the worlds climate by storing solar energy and distributing it around the planet through currents and atmospheric winds.This publication is all about developing your students understandings of earths oceans and the major effect they have on climate. Understanding and interpreting local weather data and understanding the relationship between weather and climate are important first steps to understanding larger-scale global climate changes. Activities that ask students to collect and analyze local weather data as well as analyze global data can be found in the Lessons and Activities section. Analyzing and interpreting data is a major focus of this publication. Numerous data sets can be found in the Sources for Real Data section. The Background Information section and the article Tomorrows Forecast will help reinforce your own content knowledge.

Lightle, Kimberly

2006-01-01

457

Short-term variations in mesozooplankton, ichthyoplankton, and nutrients associated with semi-diurnal tides in a patagonian Gulf  

NASA Astrophysics Data System (ADS)

The relationships between the distribution of different zooplankton and ichthyoplankton stages and physical and chemical variables were studied using samples and data (CTD profiles, ADCP and current meter measurements, nutrients, mesozooplankton, ichthyoplankton) obtained from different strata during two 24-h cycles at two oceanographic stations in a Chilean Patagonian gulf during the CIMAR 10-Fiordos cruise (November, 2004). A station located at the Chacao Channel was dominated by tidal mixing and small increments in surface stratification during high tides, leading to decreased nutrient availability. This agreed with short periods of increased phytoplankton abundance during slack waters at the end of flood currents. Increases in larval density for all zooplankton and ichthyoplankton taxa corresponded to the flooding phases of the tidal cycle. When the larval density data were fit to a sinusoidal model, the regression coefficients were high, suggesting that tides are important features that modulate short-term variations in plankton abundance. All larvae did not vary synchronously with the tidal phase; rather, time lags were observed among species. The abundances of older individuals of the copepodite Rhincalanus nasutus and all zoea stages of the squat lobster Munida gregaria increased during night flood tides, whereas younger stages increased during daytime flood tides. At a station located at the Queullin Pass, which was dominated by vertical stratification patterns, the variations in peak larval density were better fitted to the semi-diurnal sea level fluctuations. Other evidence indicated internal tides below the pycnocline, which could promote larval transport in deeper layers. In the overall picture that emerges from this study, planktonic organisms from different habitats and phylogenetic origins seem to respond to the local tidal regimes. In some cases, this response might be beneficial, transporting these individuals inshore to areas that are rich in food during the peak biological production season.

Castro, L. R.; Cáceres, M. A.; Silva, N.; Muñoz, M. I.; León, R.; Landaeta, M. F.; Soto-Mendoza, S.

2011-03-01

458

Oceans Effect on Weather and Climate  

NSDL National Science Digital Library

The Ocean's Effect on Weather and Climate SciPack explores concepts related to Earth's weather and climate. The focus is on Standards and Benchmarks related to weather and climate, the water cycle, climate change, and the role of solar energy and its affect on the atmosphere and oceans. The unique role oceans play in defining Earth's weather and climate patterns is also specifically addressed. In addition to comprehensive inquiry-based learning materials tied to Science Education Standards and Benchmarks, the SciPack includes the following additional components:? Pedagogical Implications section addressing common misconceptions, teaching resources and strand maps linking grade band appropriate content to standards. ? Access to one-on-one support via e-mail to content "Wizards".? Final Assessment which can be used to certify mastery of the concepts.Learning Outcomes:Ocean's Effect on Weather and Climate: Global Climate Patterns? Explain why the temperature of the ocean does not generally fluctuate as dramatically as the temperature of the land.? Describe the relationship between density of liquids and gases and their temperature.? Explain how a difference in density of different layers/portions of a fluid will cause internal currents (rising and falling of the fluid).? Explain the cause of predictable wind patterns along the coastal regions of large land masses.? Describe how the Coriolis Effect helps determine the direction of movement of air and water currents.? List the major variables that affect the transfer of energy through the atmosphere.? Provide an example showing how the transfer of energy affects weather and climate.? Explain how convection relates to weather, including its role in the development of circulation patterns. Ocean's Effect on Weather and Climate: Global Precipitation and Energy? Outline the basic steps in the water cycle in terms of density, energy of the water, and the relative molecular arrangement and motion in each phase.? Describe how energy is transferred to the atmosphere by heating from the ocean and by the evaporation of water and its subsequent condensation. ? Identify the Sun as the energy source that drives atmospheric circulation and the movement of masses of air and water from one place on Earth to another (via convection).? Llist sources for the water cycle and identify the largest source.? Explain the relationship between water, temperature, the amount of water evaporated into the atmosphere (and subsequently condensed), and the energy of the atmosphere at or near the location of evaporation.Ocean's Effect on Weather and Climate: Global Circulation Patterns? Explain how the oceans might influence and affect local weather and climate, given a specific location (on the planet near the ocean) and the local ocean currents.? Describe the cause of hurricanes and explain why they usually occur within specific regions during certain times of the year.? Explain how changes in ocean temperatures (over a period of months) affect factors that influence weather patterns.? List the major variables that affect the transfer of energy through the ocean.Ocean's Effect on Weather and Climate: Changing Climate? Explain the role that phenomena such as volcanic eruptions or asteroid impact play in changing climate.? Describe the type of atmospheric conditions and weather related data that can be obtained from ice core and deep-sea sediment records.? Describe how a small change in the content of oceans and atmosphere (such as a rise in carbon dioxide levels) can have significant impacts on global climate.? Describe human activity that has an affect on climate.

National Science Teachers Association (NSTA)

2007-03-28

459

Large-Scale Weather  

NSDL National Science Digital Library

In the previous chapter, we dealt with how the properties of air and water affected small-scale weather such as the formation of clouds, the formation of fog, and how comfortable you feel at different times of the year. In this chapter, we're going to go global, talking about major interactions between the Sun and Earth, the resulting effects on large air masses, and how these major interactions help us figure out what the weather's going to be tomorrow. As discussed earlier in the book, when science concepts are applied to the real world, things don't always work out exactly as expected. However, it is possible to get an overall picture of what's happening in large-scale weather.

Robertson, William C.

2005-01-01

460

Delicious Differential Weathering  

NSDL National Science Digital Library

Students are asked to place a Baby Ruth candy bar in their mouths but are asked not to bite it. Once they have sucked off all the chocolate and caramel the students are given permission to bite the peanuts. After lecturing on the differences between chemical and physical weathering students are asked to list the order of ingredients they tasted. Each group is given a sample of granite. Students are asked to list three visible minerals in the granite. Relate the minerals of the granite (hornblende, feldspar, and quartz) to the ingredients of the candy bar. Explain Bowen's reaction series and how different minerals will weather first and how climate will affect weathering rates.

Gorte, Mary

461

Interpretation of earth tide response of three deep, confined aquifers  

SciTech Connect

The response of a confined, areally infinite aquifer to external loads imposed by earth tides is examined. Because the gravitational influence of celestial objects occurs over large areas of the earth, the confined aquifer is assumed to respond in an undrained fashion. Since undrained response is controlled by water compressibility, earth tide response can be directly used only to evaluate porous medium compressibility if porosity is known. Moreover, since specific storage S/sub s/ quantifies a drained behavior of the porous medium, one cannot directly estimate S/sub s/from earth tide response. Except for the fact that barometric changes act both on the water surface in the well and on the aquifer as a whole while stress changes associated with earth tides act only in the aquifer, the two phenomena influence the confined aquifer in much the same way. In other words, barometric response contains only as much information on the elastic properties of the aquifer as the earth tide response does. Factors such as well bore storage, aquifer transmissivity, and storage coefficient contribute to time lag and damping of the aquifer response as observed in the well. Analysis shows that the observation of fluid pressure changes alone, without concurrent measurement of external stress changes, is sufficient to interpret uniquely earth tide response. In the present work, change in external stress is estimated from dilatation by assuming a reasonable value for bulk modulus. Earth tide response of geothermal aquifers from Marysville, Montana. East Mesa, California; and Raft River Valley, Idaho, were analyzed, and the ratio of S/sub 3/ to porosity was estimated. Comparison of these estimates with independent pumping tests show reasonable agreement.

Narasimhan, T.N.; Kanehiro, B.Y.; Witherspoon, P.A.

1984-03-10

462

On the modification of tides in a seasonally ice-covered sea  

NASA Astrophysics Data System (ADS)

New observations from eight moorings located in Foxe Basin, Hudson Strait, and Hudson Bay are used to study the seasonal variability of the M2 tide. Significant seasonal variations of the M2 surface elevation are found in all these regions and at all seasons. The largest variations occur during winter while both elevation increase (Hudson Strait) and decrease (Hudson Bay, Foxe Basin) are observed. These variations are found recurrent at the stations where multiyear observations are available. Observations from a velocity profiler are consistent with a seasonal damping of the tides because of friction under ice. Numerical simulations with a sea ice-ocean coupled model and realistic forcing qualitatively reproduce most of the features of the observed variability. The simulations show that the winter M2 variations are essentially caused by the under-ice friction, albeit with strong regional differences. Under-ice friction mostly occurs in a limited region (Foxe Basin) and can account for both increased and decreased M2 elevations during winter.

St-Laurent, P.; Saucier, F. J.; Dumais, J.-F.

2008-11-01

463

Weather Station Model  

NSDL National Science Digital Library

This lesson instructs students on how to read station models, the symbols used on weather maps to show data (temperature, wind speed and direction, barometeric pressure, etc.) for a given reporting station. It includes a diagram of a station model, an explanation of the data conveyed by the numbers and symbols, and a table of definitions for the graphic symbols used with models. There is also a set of interactive station models students can use for practice at interpretation, and an interactive exercise in which students use real-time weather data to interpret models.

464

Reading Weather Maps  

NSDL National Science Digital Library

From the University of Illinois at Urbana-Champaign's Department of Atmospheric Sciences comes the Reading Weather Maps Web site. Visitors learn how to convert their local time to the standard used by all meteorologists; to tell the difference between Kelvin, Celsius, and Fahrenheit temperatures; and how to read maps with weather data collected on and above the Earth's surface. For example, wind bards, which are flag-like symbols that indicate wind direction and wind speed, always point in the direction the wind is blowing "from." Other interesting facts, descriptions, and illustrations are available on the site.

1969-12-31

465