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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

Solar variability, weather, and climate  

NASA Technical Reports Server (NTRS)

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

1982-01-01

6

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

NASA Astrophysics Data System (ADS)

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

2014-03-01

7

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

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.

9

Weather variability, climatic change, and soybean production  

SciTech Connect

A crop/weather model was used to determine the effect of changing climate and weather variability on soybean production in the Corn Belt. A cooling trend from the 1930s to the 1970s was accompanied by an upward trend in July plus August rainfall. There was decreased weather variability from the 1930s to 1973 and greatly increased weather variability after 1973. Improved weather from 1930 to 1972 increased soybean yields 3 bushels/acre. Higher intensity rainfalls increased in Illinois and Iowa after 1970.

Thompson, L.M.

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

Variability of mesospheric diurnal tides and tropospheric diurnal heating during 19971998  

E-print Network

variations in large-scale tropical weather and climate systems may affect the clima- tology of the middle 1997­1998. The altered heating patterns result in a stronger forcing of the migrating diurnal tide). ENSO is a global-scale perturbation in atmospheric pressure, cloudiness, temperature and rainfall

Nesbitt, Steve

15

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

NASA Astrophysics Data System (ADS)

The 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

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

18

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

19

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

20

S2 tide aliasing in GRACE time-variable gravity solutions  

NASA Astrophysics Data System (ADS)

Errors in high-frequency ocean tide models alias to low frequencies in time-variable gravity solutions from the Gravity Recovery and Climate Experiment (GRACE). We conduct an observational study of apparent gravity changes at a period of 161 days, the alias period of errors in the S2 semidiurnal solar tide. We examine this S2 alias in the release 4 (RL04) reprocessed GRACE monthly gravity solutions for the period April 2002 to February 2008, and compare with that in release 1 (RL01) GRACE solutions. One of the major differences between RL04 and RL01 is the ocean tide model. In RL01, the alias is evident at high latitudes, near the Filchner-Ronne and Ross ice shelves in Antarctica, and regions surrounding Greenland and Hudson Bay. RL04 shows significantly lower alias amplitudes in many of these locations, reflecting improvements in the ocean tide model. However, RL04 shows continued alias contamination between the Ronne and Larson ice shelves, somewhat larger than in RL01, indicating a need for further tide model improvement in that region. For unknown reasons, the degree-2 zonal spherical harmonics (C20) of the RL04 solutions show significantly larger S2 aliasing errors than those from RL01.

Chen, J. L.; Wilson, C. R.; Seo, Ki-Weon

2009-07-01

21

Seasonal Variability of the Texas ‘Brown Tide’ ( Aureoumbra lagunensis) in Relation to Environmental Parameters  

Microsoft Academic Search

The spatial and temporal variation of salinity, specific conductivity, temprature, turbidity, pH, dissolved oxygen, redox potential, soluble reactive phosphate (SRP), ammonium, nitrate, phytoplankton and mesozooplankton within Baffin Bay, Texas were monitored monthly from April 1995–July 1996 to understand better the seasonal variability of the Texas ‘brown tide’, Aureoumbra lagunensis .High A. lagunensis densities (0·05–5·97×106cells ml?1) were observed in the summer

K. B. Rhudy; V. K. Sharma; R. L. Lehman; D. A. McKee

1999-01-01

22

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...

23

Intraannual variability of tides in the thermosphere from model simulations and in situ satellite observations  

NASA Astrophysics Data System (ADS)

In this paper, we provide insights into limitations imposed by current satellite-based strategies to delineate tidal variability in the thermosphere, as well as the ability of a state-of-the-art model to replicate thermospheric tidal determinations. Toward this end, we conducted a year-long thermosphere-ionosphere-mesosphere-electrodynamics general circulation model (TIME-GCM) simulation for 2009, which is characterized by low solar and geomagnetic activity. In order to account for tropospheric waves and tides propagating upward into the ˜30-400 km model domain, we used 3-hourly MERRA (Modern-Era Retrospective Analysis for Research and Application) reanalysis data. We focus on exospheric tidal temperatures, which are also compared with 72 day mean determinations from combined Challenging Minisatellite Payload (CHAMP) and Gravity Recovery and Climate Experiment (GRACE) satellite observations to assess the model's capability to capture the observed tidal signatures and to quantify the uncertainties associated with the satellite exospheric temperature determination technique. We found strong day-to-day tidal variability in TIME-GCM that is smoothed out when averaged over as few as ten days. TIME-GCM notably overestimates the 72 day mean eastward propagating tides observed by CHAMP/GRACE, while capturing many of the salient features of other tidal components. However, the CHAMP/GRACE tidal determination technique only provides a gross climatological representation, underestimates the majority of the tidal components in the climatological spectrum, and moreover fails to characterize the extreme variability that drives the dynamics and electrodynamics of the ionosphere-thermosphere system. A multisatellite mission that samples at least six local times simultaneously is needed to provide this quantification.

Häusler, K.; Hagan, M. E.; Forbes, J. M.; Zhang, X.; Doornbos, E.; Bruinsma, S.; Lu, G.

2015-01-01

24

Understanding Space Weather: The Sun as a Variable Star  

NASA Technical Reports Server (NTRS)

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

Strong, Keith; Saba, Julia; Kucera, Therese

2011-01-01

25

Understanding Space Weather: The Sun as a Variable Star  

NASA Technical Reports Server (NTRS)

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

Strong, Keith; Saba, Julia; Kucera, Therese

2012-01-01

26

POSSIBLE LUNAR TIDE EFFECTS ON CLIMATE AND ECOSYSTEM VARIABILITY IN THE NORDIC SEAS AND THE BARENTS SEA  

Microsoft Academic Search

The inflow of North Atlantic Water to the Norwegian Sea and the Barents Sea has a major influence on northern Europe climate and ecosystem dynamics in the Nordic Seas and the Barents Sea. In the period from 1900 to 2005, the temperature variability of North Atlantic Water and the Barents Sea temperature was correlated with the 18.6 year amplitude tide

Harald Yndestad

27

Time-variable aliasing effects of ocean tides, atmosphere, and continental water mass on monthly mean GRACE gravity field  

Microsoft Academic Search

The Gravity Recovery and Climate Experiment (GRACE) satellite mission will provide new measurements of Earth's static and time-variable gravity fields with monthly resolution. The temporal effects due to ocean tides and atmospheric mass redistribution are assumed known and could be removed using current models. In this study we quantify the aliasing effects on monthly mean GRACE gravity estimates due to

Shin-Chan Han; Christopher Jekeli; C. K. Shum

2004-01-01

28

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

29

Consistency of geoid models, altimetry, tide gauges and time-variable water levels in the North Sea  

NASA Astrophysics Data System (ADS)

In recent years, various high-resolution geoid models have been derived from the satellite missions GRACE (Gravity Recovery And Climate Experiment) and GOCE (Gravity field and steady-state Ocean Circulation Explorer). We investigate the consistency of these models at different spatial resolution with ERS-2 and ENVISAT altimeter time series and with tide gauge data in the North Sea. Corrections for tides and time-variable water levels are derived from an operational model of the Federal Maritime and Hydrographic Agency (BSH), and from other models. Special attention will be paid to the problem of homogenizing the spatial resolution of the various data sets.

Löcher, Anno; Schall, Judith; Eicker, Annette; Kusche, Jürgen; Weiß, Robert; Sudau, Astrid

2013-04-01

30

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

31

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

32

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

NASA Astrophysics Data System (ADS)

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

2013-05-01

33

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

PubMed

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. PMID:25685424

Damé, Luc

2013-05-01

34

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

35

Weather  

NSDL National Science Digital Library

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

Ms. Bullough

2010-06-24

36

Weather  

NSDL National Science Digital Library

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

Ms. Stearns

2008-10-25

37

Weather  

NSDL National Science Digital Library

Learn all about the aspects of weather that effect us every day. Click here to see a weather forecast for anywhere in the world World Wide Weather Watch See what happens to weather when you change conditions at your house Weather Maker Weather Games ...

Mrs. Hyde

2007-02-08

38

NOAA Tides Online  

NSDL National Science Digital Library

Access weather and water level observations for stations across coastal United States and the Great Lakes. Follow the "CO-OPS Website" link for tide predictions, additional weather-related observations, publications, and much more. Historical data is available for download. Site provides emergency information when a station's water level exceeds normal and is activated into Storm Surge mode.

39

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

40

Weather  

NSDL National Science Digital Library

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

Ms. Williams

2005-10-25

41

Red Tide  

NSDL National Science Digital Library

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

U.S. Centers for Disease Control

42

How does stratospheric variability affect surface weather and climate?  

NASA Astrophysics Data System (ADS)

Changes to the stratosphere, due to both natural variability and ozone depletion, have substantial effects on surface weather and climate, especially at middle to high latitudes. Despite clear evidence of these impacts, the primary dynamics of this phenomenon are not yet well understood. Here we show that the stratospheric meridional circulation forces the column of air above the Arctic downwards into the troposphere, acting like a mechanical plunger that controls the day-to-day thickness of the troposphere. This vertical motion directly affects temperatures and the strength of jets in the mid- to upper troposphere. Raising and lowering of the Arctic tropopause layer leads to stretching and compression of the tropospheric column and a north-south dipole in surface pressure similar to the Northern Annular Mode.

Baldwin, Mark; Birner, Thomas

2013-04-01

43

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

Microsoft Academic Search

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

John Michael Williams

2000-01-01

44

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

45

Weathering, Geomorphology and Climatic Variability in the Central Namib Desert  

Microsoft Academic Search

Weathering is an important component of geomorphological change in the Central Namib Desert. Previous studies have reported on the weathering role of salt and dissolution, allied with wind abrasion. However, many surface are covered by luxuriant lichen growths, fed by fog precipitation, whose weathering role has not been clarified. Here we present preliminary investigations of the role of lichens and

Heather Viles; Andrew Goudie

46

A HIGH RESOLUTION GLOBAL OCEAN MODEL with VARIABLE FORCING of WIND, HEAT, & FRESHWATER: I) INITIAL EVALUATION  

E-print Network

ocean's low freq. variability Altimetry Ocean Weather Stations TOGA/TOA Tide GaugesConclusions in Red in the Time series along America's Pacific. Red: Tide Gauge, West Coast. Black: POCM 4C El Nino~ Model. Correlations reflect similar patterns to the corr. with tide gauges to right. Reflects the high quality

Tokmakian, Robin

47

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

48

Weather  

NSDL National Science Digital Library

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

Miss Jennie

2009-10-22

49

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

Microsoft Academic Search

Elementary physical reasoning seems to leave it inevitable that global\\u000awarming would increase the variability of the weather. The first two terms in\\u000aan approximation to the global entropy are used to show that global warming has\\u000aincreased the free energy available to drive the weather, and that the variance\\u000aof the weather should increase correspondingly.

John Michael Williams

2000-01-01

50

Seasonal variability and north-south asymmetry of internal tides in the deep basin west of the Luzon Strait  

NASA Astrophysics Data System (ADS)

Temporal and spatial variability of internal tides (ITs) in the deep basin west of the Luzon Strait were examined, based on two 9-month mooring current observations from autumn 2008 to summer 2009. The baroclinic current measurements exhibited north-south asymmetry and temporal variation. At the southern site (19.5°N), the kinetic energy of diurnal IT was dominant over that of semidiurnal IT by a factor of 3 to 4, whereas at the northern site (~ 21°N), the diurnal energy was comparable to or a little larger than semidiurnal energy. At both sites, the motions of semidiurnal IT were recognized as seasonally invariant, while diurnal IT showed notable seasonal variation, namely, stronger in summer and winter but weaker in spring and autumn. The seasonal variation was mainly modulated by the astronomical tides in the Luzon Strait rather than by the seasonal thermocline. Both diurnal and semidiurnal ITs contained stronger coherent signals than incoherent counterparts at two sites, but the IT at the southern site was more coherent than that at the northern site. Diurnal IT is more coherent than the semidiurnal IT at each site. The spatial-temporal variations were probably due to IT interferences from various sources within the Luzon Strait and modulation by varying background conditions.

Xu, Zhenhua; Yin, Baoshu; Hou, Yijun; Liu, Antony K.

2014-06-01

51

Physical mechanisms of solar variability influence on weather and climate  

Microsoft Academic Search

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;

Sergei Avakyan

2010-01-01

52

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

EPA Science Inventory

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

53

The Intelligent Wind Detection System of Weather UAV Based on the Multimode Variable Structure  

Microsoft Academic Search

The present wind detection model of weather UAV has limitations. In order to detect the wind speed of multi- flight states, the intelligent wind detection system of weather UAV based on the multi-mode variable structure was proposed in this paper. According to the change of acceleration and angular velocity, three detection equations were established. Based on flight motion states, the

Zhou Shudao; Wang Yanjie; Ye Song; Zhu Guotao; Cheng Long

2011-01-01

54

Long-term MF radar observations of solar tides in the low-latitude mesosphere: Interannual variability and comparisons with the GSWM  

NASA Astrophysics Data System (ADS)

Long-term MF radar wind measurements in the 80-100 km height range made at three equatorial and subtropical sites (Adelaide, Christmas Island, and Kauai) are used to produce climatologies and to study interannual variability of solar tides. Twelve years of data were available for Adelaide and up to 6 years at the other sites and are analyzed in 30-day intervals. The climatological values are compared with the Global Scale Wave Model (GSWM). Good agreement between the measured and model amplitudes and phases is found for the diurnal tide, but the semidiurnal model values agree less well with the observations. The diurnal tidal amplitudes and phases show strong seasonal variability. Maximum amplitudes are attained in March, and subsidiary maxima are observed in July/August and October, while the phase shows an annual cycle at Adelaide and Kauai, with the phase advancing by ˜4-6 hours from summer to winter. Amplitudes of the semidiurnal tide rarely exceed 10 m s-1. The phases undergo rapid shifts around the equinoxes at Adelaide and Kauai, but there is a more complicated phase variation at Christmas Island. The diurnal tide shows strong interannual variability in amplitude, especially near the March equinox. There appears to be an association with the quasi-biennial oscillation (QBO) in zonal winds in the equatorial stratosphere, with the amplitudes being larger than the climatological average in years when the stratospheric winds are eastward and smaller than average when the QBO is in its westward phase. In contrast, the phase of the diurnal tide, as well as the semidiurnal tide, shows little systematic interannual variability.

Vincent, R. A.; Kovalam, S.; Fritts, D. C.; Isler, J. R.

1998-04-01

55

Weather  

NSDL National Science Digital Library

You will learn how to describe and observe changes in weather patterns by completing the following activities. The students will record and report changes in weather on their data sheet. The Process: Read the information on How Air Pressure Affects You. In this article you will see the term barometer. Write its definition. Now look over Weather Facts. Now go to Investigate Climate Conditions and use the weather maker to observe the effects of certain changes. Answer the questions: How much of a change in temperature is needed to make it ...

Ms. Lauren

2010-11-17

56

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.

Smithsonian Education

57

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

58

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

59

Weathering of plagioclase across variable flow and solute transport regimes  

NASA Astrophysics Data System (ADS)

SummaryThe study area is situated in a fault zone with fractured granites and metasediments. In a conceptual model, infiltrating water first passes the bedrock cover of soil and saprolite and then partly enters the fractures. Weathering reactions of minerals occur in small pores and fissures in the bedrock cover zone to continue in the larger fractures. Pumping tests were carried out in a number of boreholes to measure the drawdown as a function of pumping time. From the results, values of transmissivity ( T) could be derived. In combination with the storage coefficient ( S) for similar fault zones, the hydraulic diffusivity ( D = T/ S) could be computed. Water samples, collected from the boreholes, represent fluid packets with a history of weathering reactions in the bedrock cover and in the larger fractures. The major element composition of these samples was used by means of the SiB mass balance algorithm ( Pacheco and Van der Weijden, 1996) to calculate the moles L -1 of dissolved plagioclase (oligoclase with An ? 0.20) and the moles L -1 of secondary phases (gibbsite, halloysite, smectite) precipitated along the flow paths of the samples. These results were then used to calculate the net dissolved silica concentrations ( [HSiO40]) related to dissolution of plagioclase followed by precipitation of each of the secondary phases. An interpretation of a plot of each of these [HSiO40] 's versusD is that at D < 0.7 m 2 s -1, dissolution of plagioclase is followed by precipitation of halloysite in the large fractures of the fault zone (open system), whereas at D ? 0.7 m 2 s -1 precipitation of both halloysite and smectite occurs in the rock matrix with small fissures and pores (semi-open system). Before being pumped, the percolating fluids travelled 0.01-13.7 years. During these periods, plagioclase weathered at rates ( W Pl) of 10 -(12.9±1.1) moles m -2 s -1, which are approximately 2.2 orders of magnitude higher than solid-state weathering rates reported in various field studies. In this study, it is suggested that part of the apparent discrepancy between the results is due to changes in hydraulic diffusivity of the weathering environments occurring over the geologic times.

Pacheco, Fernando A. L.; Van der Weijden, Cornelis H.

2012-02-01

60

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

61

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

PubMed

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

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

2013-01-01

62

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

PubMed Central

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

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

2013-01-01

63

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

64

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 of neglecting rainfall spatial variability for runoff modelling at the outlet of catchments of about ten to several hundred km². In order to overcome modelling and rainfall data errors, to control the rainfall

Paris-Sud XI, Université de

65

Lunar Tides  

NSDL National Science Digital Library

This site explains the relationship between our tides on Earth and the Moon. Differential forces are explained as a function of distance from various points on Earth to the Moon. The site explains both a simple tidal model with a smooth water covered Earth and a more realistic tidal model that takes into account the earth-moon system and friction. This site also explains spring tides and neap tides and also tidal coupling and gravitational locking.

66

On the role of wind and tide in generating variability of Pearl River plume during summer in a coupled wide estuary and shelf system  

NASA Astrophysics Data System (ADS)

A numerical simulation of the buoyant river plume over the Pearl River Estuary (PRE) and adjacent shelf during a typical upwelling favorable wind period of the summer monsoon is utilized to explore the responses of the plume to wind and tide forcing. The model is forced with time-dependent river discharge, wind and tide, and it shows reasonable ability to capture the basic structure and responses of the plume. Additional numerical experiments that are forced without either wind or tide are used to evaluate the relative importance of wind and tide in generating plume variability. Results show that the vertical structure of the plume and the strength of the stratification in the estuary are determined by the combination of the buoyancy forcing associated with river discharge and tidal forcing, and vary with the advection process, while the horizontal shape and spreading of the plume over the shelf are highly influenced by the wind-driven coastal current, and are more susceptible to the change of vertical mixing. Mechanical energy analysis in each dynamical region (upper, middle, lower estuary, and shelf) reveals that this is because the system mainly gains energy from tide (wind) in the estuary (shelf), and loses energy to the bottom friction (internal-shear mixing) in the estuary (shelf). The largest forcing and dissipation terms in the middle PRE, and at the entrances of smaller estuaries such as Huang Mao Hai, are due to tidal forcing, which enables the middle PRE to serve dynamically as the entrance of an estuary, where the transition of the river plume into coastal buoyancy current usually takes place. In addition, the mixing efficiency increases from upper PRE to the shelf and from strong to weak mixing period, thus the plume in the well-mixed upper estuary is not as sensitive to the changes of wind and tide as that over the highly stratified shelf.

Zu, Tingting; Wang, Dongxiao; Gan, Jianping; Guan, Weibing

2014-08-01

67

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

NASA Astrophysics Data System (ADS)

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

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

2011-01-01

68

Perspectives of non-gaussianity in large scale weather and climate Variability  

NASA Astrophysics Data System (ADS)

Understanding non-Gaussian statistics of weather and climate variability has important consequences in the atmospheric and ocean sciences not least because weather and climate risk assessment depends on knowing and understanding the exact shape of the system's probability density function. While there is no doubt that many atmospheric variables exhibit non-Gaussian statistics on many time (and spatial) scales a full and complete understanding of this phenomenon remains a challenge. Various mechanisms behind the observed non-Gaussian statistics have been proposed but remain, however, multifaceted and scattered in the literature. Given the importance of this subject for climate research, and in an attempt to contribute to this topic a thorough review and discussion of the different mechanisms that lead to non-Gaussian weather and climate variability are presented in this paper and an outlook is given.

Hannachi, Abdel; Sura, Philip

2014-05-01

69

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 of Fisheries and Oceans

70

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

71

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 ...

Ms. Caitlin

2009-10-21

72

Simulating soybean canopy temperature as affected by weather variables and soil water potential  

NASA Technical Reports Server (NTRS)

Hourly weather data for several clear sky days during summer at Phoenix and Baltimore which covered a wide range of variables were used with a plant atmosphere model to simulate soybean (Glycine max L.) leaf water potential, stomatal resistance and canopy temperature at various soil water potentials. The air and dew point temperatures were found to be the significant weather variables affecting the canopy temperatures. Under identical weather conditions, the model gives a lower canopy temperature for a soybean crop with a higher rooting density. A knowledge of crop rooting density, in addition to air and dew point temperatures is needed in interpreting infrared radiometric observations for soil water status. The observed dependence of stomatal resistance on the vapor pressure deficit and soil water potential is fairly well represented. Analysis of the simulated leaf water potentials indicates overestimation, possibly due to differences in the cultivars.

Choudhury, B. J.

1982-01-01

73

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

74

Daily weather variables and affective disorder admissions to psychiatric hospitals.  

PubMed

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

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

2014-12-01

75

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 ...

76

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

77

"Weather" Variability Of Close-in Extrasolar Giant Planets  

E-print Network

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

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

2003-03-12

78

``Weather'' Variability of Close-in Extrasolar Giant Planets  

NASA Astrophysics Data System (ADS)

Shallow-water numerical simulations show that the atmospheric circulation of the close-in extrasolar giant planet (EGP) HD 209458b is characterized by moving circumpolar vortices and few bands/jets (in contrast to ~10 bands/jets and the absence of polar vortices on cloud-top Jupiter and Saturn). The large spatial scales of moving circulation structures on HD 209458b may generate detectable variability of the planet's atmospheric signatures. In this Letter, we generalize these results to other close-in EGPs, by noting that shallow-water dynamics is essentially specified by the values of the Rossby (Ro) and Burger (Bu) dimensionless numbers. The range of likely values of Ro (~10-2 to 10) and Bu (~1-200) for the atmospheric flow of known close-in EGPs indicates that their circulation should be qualitatively similar to that of HD 209458b. This results mostly from the slow rotation of these tidally synchronized planets.

Menou, Kristen; Cho, James Y.-K.; Seager, Sara; Hansen, Bradley M. S.

2003-04-01

79

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

80

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

81

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

82

The impact of local geochemical variability on quantifying hillslope soil production and chemical weathering  

NASA Astrophysics Data System (ADS)

Soil-mantled upland landscapes are widespread across the habitable world, support extensive life, and are the interface between the atmosphere, hydrosphere, and lithosphere but typically are not cultivated. Soil found across such landscapes fits the conceptual framework of a physically mobile layer derived from the underlying parent material along with some locally derived organic content. The extent and persistence of these upland soils depend on the long-term balance between soil production and erosion. Here we briefly review methods used to quantify the physical and chemical processes of soil production and erosion and revisit three granitic study areas in southeastern Australia and northern California that enabled early quantification of the soil production function and topographic controls on chemical weathering. We then present new major and trace element data from 2-m by 2-m pits dug at each field site to quantify local variability of Zr concentrations and the chemical index of alteration (CIA), weathering indices used to determine chemical weathering rates and extents in soils and saprolites. Using both new and previously published data, we compare differences between local variability and regional, as well as intersite variability of these important indices. For each of the 2-m pits, we collected 25 samples and found that the simple mean and the 2? standard deviation best describe the local variation in the data. We also find that the variability in the 2-m pit data lies within variability observed in the same data from samples collected in individual soil pits across each of the field sites and that the differences between sites are consistent with previously published results. These observations highlight the importance of quantifying local scale variability in studies that use similar, multifaceted measurements to quantify hillslope soil production and erosion processes.

Heimsath, Arjun M.; Burke, Benjamin C.

2013-10-01

83

Tides and Water Levels: What are Tides?  

NSDL National Science Digital Library

This tutorial is an overview of the complex systems that govern the movement of tides and water levels. The tutorial is content rich and presented in easy-to-understand language with many illustrative and interactive graphics to visually enhance the text. This page begins with what tides are while other linked pages cover What Causes Tides, Gravity, Inertia, and Bulges, Changing Angles and Tides, The Frequency of Tides, Tidal Variations, Types and Causes of Tidal Cycles, What Else Affects Tides, Monitoring the Tides, How are Tides Measured, and a page of references.

84

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

85

The "Year" of Tropical Convection (May 2008 to April 2010):2 Climate Variability and Weather Highlights3  

E-print Network

1 1 The "Year" of Tropical Convection (May 2008 to April 2010):2 Climate Variability and Weather Climáticos, Sao Paulo, Brazil26 15 University of Arizona, Tucson, AZ, USA27 16 Centre for Australian Weather and Climate Research, Melbourne, Australia28 17 University of Washington, Seattle, USA29 18 North Caroline

Yuter, Sandra

86

One centimeter-level observations of diurnal ocean tides from global monthly mean time-variable gravity fields  

Microsoft Academic Search

A method of analyzing GRACE satellite-to-satellite ranging data is presented which accentuates signals from diurnal ocean\\u000a tides and dampens signals from long-period non-tidal phenomena. We form a time series of differences between two independent\\u000a monthly mean gravity solutions, one set computed from range-rate data along strictly ascending arcs and the other set computed\\u000a from data along descending arcs. The solar

Shin-Chan Han; Richard D. Ray; Scott B. Luthcke

2010-01-01

87

Using a Weather Generator and SWAT to Improve Understanding of Variability in Watershed Flows and Phosphorous Transport  

NASA Astrophysics Data System (ADS)

Reliable weather data and accurate predictions of their variability can increase the reliability and precision of the current hydrologic modeling and analysis scenario. This paper explores the use of a network of coherent stochastic models called "weather generators", which correct the low bias in basin-wide precipitation which is a result of only low-elevation observation stations. The water quality model used for this purpose was SWAT2000, applied on the Cannonsville watershed in central New York. The previous studies on this watershed used weather data from the traditionally placed weather stations, lying on lower, more easily accessible elevations and these observing stations yield persistently under-estimated data. However, weather parameters show a strong dependence on elevation. So, we used the weather observing stations within and nearby the Cannonsville watershed with a DEM of the region and interpolated weather generator parameters at high spatial resolution and found the correcting factors that would give us a better estimate of weather input to the watershed model for calibrating model parameters to historical data. The weather generator was also used to develop 10 different weather scenarios that were later used to make forecasts about water quality. The improved weather pattern was then used to recalibrate SWAT2000 on flow, sediment and phosphorous using Dynamically Dimensioned Search (DDS) algorithm. The improved weather pattern resulted in somewhat different values of calibrated parameters, expected to be better in prediction, given the better quality of spatially distributed weather. The recalibrated model was compared to the original model (Tolson and Shoemaker, 2006b). After the watershed model is recalibrated with better quality weather data, the weather generator was used to generate new weather scenarios at high spatial resolution. Since the weather is uncertain, many weather scenarios, starting in 2007, will be used for model runs to generate future hydrological output, especially the amount of phosphorus in dissolved and particulate form that enters the Cannonsville reservoir. The statistical characteristics of the output from the re-calibrated model, including the number of times the TMDL is violated and the annual averages, are computed and are used to calculate the mean expected increase in phosphorus levels and the ranges on the same. Though the region of study and the data taken were for Cannonsville watershed, the results of this study and the methods employed were found to be applicable in general to any watershed.

Gaur, S.; Shoemaker, C. A.; Wilks, D.; Cowan, D.

2008-05-01

88

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

89

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. H.

2003-05-01

90

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

91

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

92

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

NASA Astrophysics Data System (ADS)

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

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

1997-12-01

93

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

PubMed Central

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

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

2014-01-01

94

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

95

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

96

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

97

Plant development scores from fixed-date photographs: the influence of weather variables and recorder experience  

NASA Astrophysics Data System (ADS)

In 1944, John Willis produced a summary of his meticulous record keeping of weather and plants over the 30 years 1913 1942. This publication contains fixed-date, fixed-subject photography taken on the 1st of each month from January to May, using as subjects snowdrop Galanthus nivalis, daffodil Narcissus pseudo-narcissus, horse chestnut Aesculus hippocastanum and beech Fagus sylvatica. We asked 38 colleagues to assess rapidly the plant development in each of these photographs according to a supplied five-point score. The mean scores from this exercise were assessed in relation to mean monthly weather variables preceding the date of the photograph and the consistency of scoring was examined according to the experience of the recorders. Plant development was more strongly correlated with mean temperature than with minimum or maximum temperatures or sunshine. No significant correlations with rainfall were detected. Whilst mean scores were very similar, botanists were more consistent in their scoring of developmental stages than non-botanists. However, there was no overall pattern for senior staff to be more consistent in scoring than junior staff. These results suggest that scoring of plant development stages on fixed dates could be a viable method of assessing the progress of the season. We discuss whether such recording could be more efficient than traditional phenology, especially in those sites that are not visited regularly and hence are less amenable to frequent or continuous observation to assess when a plant reaches a particular growth stage.

Sparks, T. H.; Huber, K.; Croxton, P. J.

2006-05-01

98

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

99

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

100

A systematic review and meta-analysis of the effects of extreme weather events and other weather-related variables on Cryptosporidium and Giardia in fresh surface waters.  

PubMed

Global climate change is expected to impact drinking water quality through multiple weather-related phenomena. We conducted a systematic review and meta-analysis of the relationship between various weather-related variables and the occurrence and concentration of Cryptosporidium and Giardia in fresh surface waters. We implemented a comprehensive search in four databases, screened 1,228 unique citations for relevance, extracted data from 107 relevant articles, and conducted random-effects meta-analysis on 16 key relationships. The average odds of identifying Cryptosporidium oocysts and Giardia cysts in fresh surface waters was 2.61 (95% CI = 1.63-4.21; I(2) = 16%) and 2.87 (95% CI = 1.76-4.67; I(2) = 0%) times higher, respectively, during and after extreme weather events compared to baseline conditions. Similarly, the average concentration of Cryptosporidium and Giardia identified under these conditions was also higher, by approximately 4.38 oocysts/100 L (95% CI = 2.01-9.54; I(2) = 0%) and 2.68 cysts/100 L (95% CI = 1.08-6.55; I(2) = 48%). Correlation relationships between other weather-related parameters and the density of these pathogens were frequently heterogeneous and indicated low to moderate effects. Meta-regression analyses identified different study-level factors that influenced the variability in these relationships. The results can be used as direct inputs for quantitative microbial risk assessment. Future research is warranted to investigate these effects and potential mitigation strategies in different settings and contexts. PMID:25719461

Young, Ian; Smith, Ben A; Fazil, Aamir

2015-03-01

101

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

E-print Network

the partitioning of net all-wave radiation into sensible and latent heat fluxes as well as heat storageImpacts of weather variability on turbulent heat fluxes in Phoenix, AZ and Portland, OR 1 2 12 2 3 Meteorology 41: 792-810. rimmond CSB, Oke TR. 2002. Turbulent heat fluxes in urban areas: observations

Hall, Sharon J.

102

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

NASA Astrophysics Data System (ADS)

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

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

2014-09-01

103

Modeling Variable-density Groundwater Flow in Coastal Aquifer: Submarine Groundwater Discharge (SGD), Tides Influence and Nearshore Circulation  

Microsoft Academic Search

Two-dimensional variable density simulations are performed for a coastal area of the northeastern Gulf of Mexico by applying finite difference model SEAWAT2000. For modeling, piezometers are installed along the coastline perpendicularly and sensors in particular piezometers keep providing hydraulic head and salinity observations by every 10 minutes in company with the changes of sea level. The influence of oscillations of

X. Li; B. X. Hu; W. C. Burnett

2007-01-01

104

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

105

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

106

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

NASA Technical Reports Server (NTRS)

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

Schubert, Siegfried D.; Lim, Young-Kwon

2012-01-01

107

Deriving meteorological variables from numerical weather prediction model output: A nearest neighbor approach  

NASA Astrophysics Data System (ADS)

This paper presents the application of variations in a nearest neighbor resampler approach for generating local-scale meteorological variables from numerical weather prediction model output. On the basis of measure of closeness and sampling strategy, six nearest neighbor models were designed. The proposed models were applied to downscale station daily precipitation and minimum and maximum temperature fields for the Chute-du-Diable meteorological station in northeastern Canada. Suites of deterministic diagnostic measures were employed for evaluating individual models as well as for intercomparison among the downscaling models. On the basis of intercomparison among models a relatively better nearest neighbor resampler was identified and the subsequent model was further investigated with a focus on downscaling daily precipitation. Suites of conventional and distribution-based diagnostic measures were employed for evaluating the skill of the downscaled precipitation over the raw numerical model output. The comparative results showed that the downscaled precipitation had greater skill values based on different performance measures which include median bias, Brier skill score, ranked probability skill score, discrimination, reliability, and relative operating characteristics.

Muluye, Getnet Y.

2011-07-01

108

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

109

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.

110

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.

Alaska Sea Grant

2011-01-01

111

Surface manifestation of internal tides in the deep ocean: observations from altimetry and island gauges  

Microsoft Academic Search

The sea-surface height signatures of internal tides in the deep ocean, amounting to a few centimeters or less, are studied using two complementary measurement types: satellite altimetry and island tide gauges. Altimetry can detect internal tides that maintain coherence with the astronomical forcing; island gauges can monitor temporal variability which, in some circumstances, is due to internal tides varying in

Richard D. Ray; Gary T. Mitchum

1997-01-01

112

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

113

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

114

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

E-print Network

Table 1 Highest tides (tide ranges) of the global ocean Country Site Tide range (m) Canada Bay the world that results in Tide Waves. The moon exerts more than twice as great a force on the tides as the sun due to its much closer position to the earth. As a result, the tide closely follows the moon

Gorban, Alexander N.

115

Atmospheric Tides over the Pyrenees. Observational study and numerical simulation  

NASA Astrophysics Data System (ADS)

Atmospheric tides refer to the oscillations in the atmosphere whose periods are integral fractions of a day. In some magnitudes (e.g. temperature), these oscillations are quite evident but in others, such as the pressure in the midlatitudes, they are usually masked by the greater variations produced during the transient pass of synoptic weather systems. The main forcing agent for these oscillations, as opposed to ocean tides, is not the solar or lunar gravity pull, but the daily variations in solar insolation and the thermal effect derived from it. The main components of the solar atmospheric tides are the semidiurnal, with a 12-hour period, and the 24-hour period component or diurnal tide. The global scale tides are usually referred to as migrating tides, and are the result of a gravity wave which travels westerly with the apparent motion of the sun. Nevertheless, a significant part of the tide can be related to local characteristics, and this part is considered as the non-migrating component of the tide. Barometric tides around the Pyrenees mountain range are analyzed by means of ground synoptic stations data recorded during one year, ground data from PYREX experiment and the CRA/LA VHF wind profiler installed in the North of the range. Tides are decomposed in their diurnal and semidiurnal components. Diurnal tides show a strong non migrating component and are very dependent on local conditions. Semidiurnal tides are more homogeneous and present a north-south asymmetry, also noted in the Alps. This cross-range asymmetry seems to be related to some interference effect caused by the mountain range in the migrating semidiurnal tide wave. The diurnal component asymmetry presents a very strong seasonal variation, so its cause must be probably related to thermal local conditions. A three month simulation carried out with NCAR's WRF limited area model reproduces this asymmetry and some of the features of the observed tides.

Diaz de Argandoña, Javier; Ezcurra, Agustin; Saenz, Jon; Campistron, Bernard; Ibarra-Berastegi, Gabriel; Saïd, Frederique

2010-05-01

116

Non-systematic weathering profile in the Blue Ridge Mountains, N. C. : Role of geochemical variables  

SciTech Connect

Weathering profiles from representative cores of the Coweeta Group, schist, and Tallulah Falls Fm, gneiss, in the Blue Ridge Mountains of North Carolina were examined. The predominant alteration minerals, which formed from the partial alteration of biotite and plagioclase, include kaolinite, chlorite, vermiculite interstratified with biotite, gibbsite. These mineral phases were identified using petrographic observation, SEM, X-ray diffraction, and selected electron microprobe analysis. These minerals commonly represent a weathering profile (developed from surface to depth on a single source rock) ranging from mature (gibbsite), to intermediate (kaolinite + interlayered biotite/vermiculite), to immature (plagioclase + biotite) at depth. In this study, however, there is no clear vertical zonation of the weathering profile. This indicates a more selective weathering process than would typically be assumed. This nonsystematic weathering profile may reflect variations in bulk composition of the parent rock and/or variations in the composition of ground water. The presence and abundance of gibbsite in these weathering profiles is unusual because it is normally associated with bauxite in which the Al[sub 2]O[sub 3] content is > 80 wt.%. In this study the Al[sub 2]O[sub 3] content of the regolith is approximately 20 wt.%. The presence of gibbsite emphasizes the importance of solution-reprecipitation of Al-rich phases as an independent process in temperature climates, and suggests the activity of silica is more critical than regional climatological effects in controlling regolith formation.

Ciampone, M.A.; McVey, D.E.; Gerke, T.L.; Briggs, W.D.; Zhang, Yangsheng; Maynard, J.B.; Huff, W.D. (Univ. of Cincinnati, OH (United States). Dept. of Geology)

1992-01-01

117

Spatial variability of characteristics and origins of urban wet weather pollution in combined sewers.  

PubMed

An experimental on-site observatory of urban pollutant loads in combined sewers was created in the centre of Paris to quantify and characterise the dry and wet weather flow in relation to spatial scale. Eight rainfall events were studied from April 2003 to May 2004. Samples were analysed for suspended solids, organic matter, nitrogen and heavy metals. Results confirm the extent of wet weather pollution. They have shown the relative homogeneity of SS and organic matter characteristics from one urban catchment area to another. Two groups of heavy metals were identified. The first one concerns Cu, which has a higher concentration in wet weather flow (WWF) than in dry weather flow (DWF), and runoff. The second includes Cd, Pb and Zn, where higher concentrations were measured in urban runoff than in WWF and DWF. A first evaluation of contribution of wastewater, urban runoff and sewer deposit erosion sources to wet weather pollution was established and has highlighted the contribution of wastewater and sewer deposits to this pollution. However, it has shown that sewer deposit erosion remains an important source of wet weather pollution at different spatial scales. PMID:16206844

Kafi-Benyahia, M; Gromaire, M G; Chebbo, G

2005-01-01

118

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

119

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.

120

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

121

Seasonal variation of the M 2 tide  

NASA Astrophysics Data System (ADS)

The seasonal cycle of the main lunar tidal constituent M 2 is studied globally by an analysis of a high-resolution ocean circulation and tide model (STORMTIDE) simulation, of 19 years of satellite altimeter data, and of multiyear tide-gauge records. The barotropic seasonal tidal variability is dominant in coastal and polar regions with relative changes of the tidal amplitude of 5-10 %. A comparison with the observations shows that the ocean circulation and tide model captures the seasonal pattern of the M 2 tide reasonably well. There are two main processes leading to the seasonal variability in the barotropic tide: First, seasonal changes in stratification on the continental shelf affect the vertical profile of eddy viscosity and, in turn, the vertical current profile. Second, the frictional effect between sea-ice and the surface ocean layer leads to seasonally varying tidal transport. We estimate from the model simulation that the M 2 tidal energy dissipation at the sea surface varies seasonally in the Arctic (ocean regions north of 60°N) between 2 and 34 GW, whereas in the Southern Ocean, it varies between 0.5 and 2 GW. The M 2 internal tide is mainly affected by stratification, and the induced modified phase speed of the internal waves leads to amplitude differences in the surface tide signal of 0.005-0.0150 m. The seasonal signals of the M 2 surface tide are large compared to the accuracy demands of satellite altimetry and gravity observations and emphasize the importance to consider seasonal tidal variability in the correction processes of satellite data.

Müller, Malte; Cherniawsky, Josef Y.; Foreman, Michael G. G.; von Storch, Jin-Song

2014-01-01

122

Non-systematic weathering profile in the Blue Ridge Mountains, N. C. : Role of geochemical variables  

Microsoft Academic Search

Weathering profiles from representative cores of the Coweeta Group, schist, and Tallulah Falls Fm, gneiss, in the Blue Ridge Mountains of North Carolina were examined. The predominant alteration minerals, which formed from the partial alteration of biotite and plagioclase, include kaolinite, chlorite, vermiculite interstratified with biotite, gibbsite. These mineral phases were identified using petrographic observation, SEM, X-ray diffraction, and selected

M. A. Ciampone; D. E. McVey; T. L. Gerke; W. D. Briggs; Yangsheng Zhang; J. B. Maynard; W. D. Huff

1992-01-01

123

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

PubMed

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

2001-05-01

124

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

125

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

126

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

127

Weather on Other Worlds. III. A Survey for T Dwarfs with High-amplitude Optical Variability  

NASA Astrophysics Data System (ADS)

We have monitored 12 T dwarfs with the Kitt Peak 2.1 m telescope using an F814W filter (0.7-0.95 ?m) to place in context the remarkable 10%-20% variability exhibited by the nearby T dwarf Luhman 16B in this wavelength regime. The motivation was the poorly known red optical behavior of T dwarfs, which have been monitored almost exclusively at infrared wavelengths, where variability amplitudes greater than 10% have been found to be very rare. We detect highly significant variability in two T dwarfs. The T2.5 dwarf 2MASS 13243559+6358284 shows consistent ~17% variability on two consecutive nights. The T2 dwarf 2MASS J16291840+0335371 exhibits ~10% variability that may evolve from night to night, similarly to Luhman 16B. Both objects were previously known to be variable in the infrared, but with considerably lower amplitudes. We also find evidence for variability in the T6 dwarf J162414.37+002915.6, but since it has lower significance, we conservatively refrain from claiming this object as a variable. We explore and rule out various telluric effects, demonstrating that the variations we detect are astrophysically real. We suggest that high-amplitude photometric variability for T dwarfs is likely more common in the red optical than at longer wavelengths. The two new members of the growing class of high-amplitude variable T dwarfs offer excellent prospects for further study of cloud structures and their evolution.

Heinze, Aren N.; Metchev, Stanimir; Kellogg, Kendra

2015-03-01

128

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

129

Tides and tsunamis  

NASA Technical Reports Server (NTRS)

Although tides and tsunamis are both shallow water waves, it does not follow that they are equally amenable to an observational program using an orbiting altimeter on a satellite. A numerical feasibility investigation using a hypothetical satellite orbit, real tide observations, and sequentially increased levels of white noise has been conducted to study the degradation of the tidal harmonic constants caused by adding noise to the tide data. Tsunami waves, possibly a foot high and one hundred miles long, must be measured in individual orbits, thus requiring high relative resolution.

Zetler, B. D.

1972-01-01

130

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

131

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

132

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

133

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

134

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

NASA Astrophysics Data System (ADS)

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

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

2012-01-01

135

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

136

Weather variability and interannual responses of the vegetation and crops in Cordoba-Argentina assessed by AVHRR derived vegetation indices  

NASA Astrophysics Data System (ADS)

Advanced Very High Resolution Radiometer (AVHRR) based vegetation indices are widely accepted as good indicators for providing vegetation properties and associated changes for large scale geographic regions. Also, their capability to indicate moisture conditions makes them an important data source for monitoring climate variations and droughts. The objective of this study was to assess the seasonal interannual responses of vegetation and crops to the weather variability. Time-series analysis of AVHRR Normalized Difference Vegetation Index (NDVI) and vegetation health indices weekly composite data collected during 1981-2003 were used to generate the seasonal vegetation curves for each of the departments (administrative unite) of the Cordoba province in Argentina, and to calculate the onset of the growing seasons. Yield series of corn and soybean for each of the departments were analyzed against AVHRR derived indices and seasonal precipitation data from the meteorological stations in the province. Results from the analysis showed that the variability of the indices serves as good proxy for identifying climate variations and thus provide insights into understanding the regional climate carrying capacity, the climate anomalies and the effects of the climate variability on vegetation, on the onset and length of the growing season and on the yields of agricultural crops.

Seiler, R.; Kogan, F.; Vinocur, M.

137

Internal Tide Generation in the Deep Ocean  

Microsoft Academic Search

Internal tides are internal gravity waves generated in stratified waters by the interaction of barotropic tidal currents with variable bottom topography. They play a role in dissipating tidal energy and lead to mixing in the deep ocean. Key dimensionless parameters governing their generation include the tidal excursion compared with the scale of the topography, the bottom slope compared with the

Chris Garrett; Eric Kunze

2007-01-01

138

A study of climate and weather variability over the tropical southwest Indian Ocean  

Microsoft Academic Search

Summary The climatology and variability of summer convection and circulation over the tropical southwest Indian Ocean is investigated using satellite imagery, routine synoptic observations, outgoing longwave radiation (OLR) data, sea surface temperatures (SST) and areal averaged rainfall departures. OLR has a -0.90 correlation with rainfall departures and the OLR minimum (ITCZ) in January and February lies across the 10°S latitude,

M. R. Jury; B. Pathack

1991-01-01

139

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

140

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

141

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

142

Synoptic Scale Weather Patterns Associated with Annual Snow Accumulation Variability in North-Central Greenland  

NASA Astrophysics Data System (ADS)

Previous studies on the synoptic forcing of high elevation areas of central Greenland have mostly relied on ice cores, snow pits, mesoscale models, and climate models. In this study, a radar-measured 118-year annual snow accumulation record (1889-2006) along a 375 km traverse between NGRIP and NEEM ice camps in Greenland is used. A Self-Organizing Maps (SOM) algorithm is applied to a reanalysis forecast model (20th Century Reanalysis Data Version 2 (1870 to 2008)) to identify recurring patterns in the sea level pressure (SLP) field that impact meteorological processes and explain annual variations of accumulation over North-Central Greenland for the 118 year period. The SOM algorithm identified 36 representative daily SLP patterns over the North Atlantic region. Synoptic weather patterns shown in these SLP patterns include cyclone splitting, cyclone-blocking, and cyclone tracks indicating changes in cyclone position and cyclone intensity. Based on radar-measured annual snow accumulation, common SLP patterns for wet years (more accumulation) over North-Central Greenland are characterized by low pressure systems surrounding Greenland or cyclones approaching the west coast of Greenland, conveying moisture through a topographically lifted onshore flow; these patterns are mostly associated with negative/neutral NAO index. In dry years (less accumulation), prevailing patterns are characterized by cyclones positioned a long distance away in the Atlantic Ocean south of Greenland, which are mainly associated with a positive NAO index. Extreme wet year prevailing patterns of NGRIP-NEEM traverse southern portion show a distinct departure from the above described North-Central Greenland general patterns by having more frequent positive-NAO days, which is similar to dry and extreme dry years. Model precipitation amounts over North-Central Greenland from the 20th Century Reanalysis Data are found to be overestimated by up to 10 cm/year.

Shu, Chen

143

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

144

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

PubMed Central

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

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

2013-01-01

145

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

146

Atmospheric Tides over the Pyrenees. Observational study and numerical simulation  

Microsoft Academic Search

Atmospheric tides refer to the oscillations in the atmosphere whose periods are integral fractions of a day. In some magnitudes (e.g. temperature), these oscillations are quite evident but in others, such as the pressure in the midlatitudes, they are usually masked by the greater variations produced during the transient pass of synoptic weather systems. The main forcing agent for these

Javier Diaz de Argandoña; Agustin Ezcurra; Jon Saenz; Bernard Campistron; Gabriel Ibarra-Berastegi; Frederique Saïd

2010-01-01

147

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

148

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

149

Tides and Water Levels  

NSDL National Science Digital Library

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

150

FORAGING SOURCES AND EFFECTS OF SELECTED PLANT CHARACTERS AND WEATHER VARIABLES ON THE VISITATION INTENSITY OF HONEYBEE, Apis mellifera adansonii (Hymenoptera: Apidae) IN THE SOUTHWEST NIGERIA  

Microsoft Academic Search

Summary This study identified field foraging sources and the effects of selected plant characters and weather variables on the visitation intensities of the honeybee, Apis mellifera adansonii in se- lected sites in Ibadan and Ogbomosho, Southwest Nigeria. Results indicated a total of 41 fora- ging sources of which 36 were common to the two sites while two other species were

Adebayo A. O moloye

151

VULNERABILITY ASSESSMENT OF SAN JOAQUIN BASIN WATER SUPPLY, ECOLOGICAL RESOURCES, AND RURAL ECONOMY DUE TO CLIMATE VARIABILITY AND EXTREME WEATHER EVENTS  

EPA Science Inventory

This project is assessing the vulnerability of water supply, water demand, water quality, ecosystem health, and socioeconomic welfare within the San Joaquin River Basin as a function of climate variability and extreme weather events. It is being funded by the EPA Global Change Re...

152

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

153

Time Series Analyses of Hand, Foot and Mouth Disease Integrating Weather Variables  

PubMed Central

Background The past decade witnessed an increment in the incidence of hand foot mouth disease (HFMD) in the Pacific Asian region; specifically, in Guangzhou China. This emphasized the requirement of an early warning system designed to allow the medical community to better prepare for outbreaks and thus minimize the number of fatalities. Methods Samples from 1,556 inpatients (hospitalized) and 11,004 outpatients (non-admitted) diagnosed with HFMD were collected in this study from January 2009 to October 2013. Seasonal Autoregressive Integrated Moving Average (SARIMA) model was applied to establish high predictive model for inpatients and outpatient as well as three viral serotypes (EV71, Pan-EV and CA16). To integrate climate variables in the data analyses, data from eight climate variables were simultaneously obtained during this period. Significant climate variable identified by correlation analyses was executed to improve time series modeling as external repressors. Results Among inpatients with HFMD, 248 (15.9%) were affected by EV71, 137 (8.8%) were affected by Pan-EV+, and 436 (28.0%) were affected by CA16. Optimal Univariate SARIMA model was identified: (2,0,3)(1,0,0)52 for inpatients, (0,1,0)(0,0,2)52 for outpatients as well as three serotypes (EV71, (1,0,1)(0,0,1)52; CA16, (1,0,1)(0,0,0)52; Pan-EV, (1,0,1)(0,0,0)52). Using climate as our independent variable, precipitation (PP) was first identified to be associated with inpatients (r = 0.211, P = 0.001), CA16-serotype (r = 0.171, P = 0.007) and outpatients (r = 0.214, P = 0.01) in partial correlation analyses, and was then shown a significant lag in cross-autocorrelation analyses. However, inclusion of PP [lag -3 week] as external repressor showed a moderate impact on the predictive performance of the SARIMA model described here-in. Conclusion Climate patterns and HFMD incidences have been shown to be strongly correlated. The SARIMA model developed here can be a helpful tool in developing an early warning system for HFMD. PMID:25729897

Song, Yuanbin; Wang, Fan; Wang, Bin; Tao, Shaohua; Zhang, Huiping; Liu, Sai; Ramirez, Oscar; Zeng, Qiyi

2015-01-01

154

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

155

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.

156

The effects of daily weather variables on psychosis admissions to psychiatric hospitals  

NASA Astrophysics Data System (ADS)

Several studies have noted seasonal variations in admission rates of patients with psychotic illnesses. However, the changeable daily meteorological patterns within seasons have never been examined in any great depth in the context of admission rates. A handful of small studies have posed interesting questions regarding a potential link between psychiatric admission rates and meteorological variables such as environmental temperature (especially heat waves) and sunshine. In this study, we used simple non-parametric testing and more complex ARIMA and time-series regression analysis to examine whether daily meteorological patterns (wind speed and direction, barometric pressure, rainfall, sunshine, sunlight and temperature) exert an influence on admission rates for psychotic disorders across 12 regions in Ireland. Although there were some weak but interesting trends for temperature, barometric pressure and sunshine, the meteorological patterns ultimately did not exert a clinically significant influence over admissions for psychosis. Further analysis is needed.

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

2013-07-01

157

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.

158

Tidal friction for semidiurnal tides  

Microsoft Academic Search

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

R. D. Pingree; D. K. Griffiths

1987-01-01

159

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.

CBS News

160

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

161

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

162

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

163

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

164

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.

165

Fracture characteristics in weathered granites  

Microsoft Academic Search

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

Judy Ehlen

1999-01-01

166

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

167

High Tide on Io!  

NSDL National Science Digital Library

This site provides a discussion of movement on the surface of Io, a satellite of Jupiter. It makes comparisons between ground movement on Io, where the ground itself moves up and down like an elevator taking people to the top and bottom of a 30-story building, and the earth, where similar ground tides cause total movements of only 8 inches. Galileo spacecraft and its visit to Io are briefly described.

168

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

169

SWUSV: a microsatellite mission for space weather early forecasting of major flares and CMEs and the complete monitoring of the ultraviolet solar variability influence on climate  

NASA Astrophysics Data System (ADS)

The SWUSV (Space Weather & Ultraviolet Solar Variability) proposed microsatellite mission encompasses three major scientific objectives: (1) Space Weather including the prediction and detection of major eruptions and coronal mass ejections (using Lyman-Alpha and Herzberg continuum imaging and H-Alpha ground support); (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 10 to 20 nm, including ozone, plus Lyman-Alpha and the CN bandhead); (3) simultaneous local radiative budget of the Earth, UV to IR, with an accuracy better than 1% in differential. The mission is on a sun-synchronous polar orbit and proposes 5 instruments to 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 2020-2021. With opening to Chinese collaboration (ESA-CAS Small Mission) a further instrument could be added (HEBS, High Energy Burst Spectrometers) to reinforced Space Weather flares prediction objectives.

Damé, Luc

170

Yellowstone Weather  

NSDL National Science Digital Library

Yellowstone National Park's high altitude and mountainous terrain makes weather prediction very difficult. This website provides seasonal weather information, average temperature and precipitation data, links to weather forecasts, and other weather links.

Yellowstone National Park

171

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

172

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

173

Tide gate valve  

SciTech Connect

A tide gate check valve in which at least three converging sides are provided at a tapered region of a flexible sleeve, so that on reverse back pressure build-up of fluid, reverse fluid flow is prevented, while the valve sleeve does not invert or collapse. The present configuration features embedded reinforcing elements for resisting inversion or collapsing when the back pressure builds up. This feature is especially important for large-sized conduits of 36'' or 72'' diameter, or even larger, such as are common in storm sewer applications.

Raftis, S. G.

1985-01-08

174

The King of Tides  

NSDL National Science Digital Library

This well-constructed WebQuest begins with the announcement: “The moon has been accused of causing the tides! Using real data collected from the Internet, your team’s job is to bring proof one way or another!” 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.

Bill Byles

2003-11-21

175

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

176

Thermal Tide Observations with the Mars Climate Sounder  

NASA Astrophysics Data System (ADS)

We present the results of an analysis of thermal tides using data from the Mars Climate Sounder (MCS). These data include both depth-weighted atmospheric temperatures (15?m brightness temperatures) and temperature profiles retrieved from limb radiance measurements. The depth-weighted temperatures (~30 Pa) are particularly useful for assessing seasonal variations and interannual variability as, unlike the profile retrievals, they are not compromised by dust storm events or thick layers of water ice clouds. The relatively recent addition of cross-track limb viewing provides broader local time coverage (at roughly 6 unequally spaced local times) that results in improved characterization of the thermal tides over the nominal twice daily observations provided by the along-track viewing. The additional local time coverage enables the identification of the amplitude and phase structure of the migrating diurnal and semi-diurnal tides. Tides are the atmospheric response to diurnally varying forcing and the migrating semi-diurnal tide is particularly sensitive to radiative heating by dust and water ice clouds. The additional local time coverage enables us to better constrain these tide modes and evaluate their response to seasonally evolving aerosol loading. We compare the MCS observations with results from the GFDL Mars global circulation model and discuss the relationship between aerosol forcing and temperature response. We find further evidence that water ice clouds make a significant contribution to tide forcing, as initially described in Kleinboehl et al. (GRL, 2013). The increased number of local time observations also allows the distinction between stationary planetary waves and non-migrating semi-diurnal tides, and the unambiguous differentiation of eastward- and westward-propagating non-migrating tides. Eastward propagating, diurnal period Kelvin waves are found to be particularly prominent in the upper atmosphere and these appear to have a well-defined seasonal cycle.

Wilson, R.; Guzewich, S.; Banfield, D. J.; Kleinboehl, A.

2013-12-01

177

NOAA: About Water Levels, Tides and Currents  

NSDL National Science Digital Library

A comprehensive lesson on what causes tides, current and past techniques for predicting tides, how and why water level is measured, and the challenges of measuring water currents. Site provides additional links to other NOAA tide resources.

178

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

179

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

180

Model which Generates Red Tides  

Microsoft Academic Search

DINOFLAGELLATES and Trichodesmium are the algae most commonly responsible for the discolorations of the sea known as red tides. These blooms are rarely observed until their development is complete, so that the events which lead to red tides remain enigmatic. Dinoflagellates are distinguished by their relatively large size compared with other flagellated algae, and by their greater swimming speeds. Many

T. Wyatt; J. Horwood

1973-01-01

181

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.

Rick Hampson

182

Tides of the British Seas  

ERIC Educational Resources Information Center

Examines the gravitational effects and the way that local conditions interact with these effects to produce the tides characteristic of the British seas. Presents some effects of tides including the possibility of harnessing tidal energy and the effect of tidal friction on the use of the earth as a clock. (GS)

Sandon, Frank

1975-01-01

183

Surface manifestation of internal tides in the deep ocean: observations from altimetry and island gauges  

NASA Astrophysics Data System (ADS)

The sea-surface height signatures of internal tides in the deep ocean, amounting to a few centimeters or less, are studied using two complementary measurement types: satellite altimetry and island tide gauges. Altimetry can detect internal tides that maintain coherence with the astronomical forcing; island gauges can monitor temporal variability which, in some circumstances, is due to internal tides varying in response to changes in the oceanic medium. This latter mechanism is at work at Hilo and other stations on the northern coasts of the Hawaiian Islands. By detecting spatially coherent low-frequency internal-tide modulations, the tide gauges, along with inverted echo sounders at sea, suggest that the mean internal tide is also spatially coherent; satellite altimetry confirms this. At Hawaii and in many other places, Topex/Poseidon altimetry detects mean surface waves, spatially coherent and propagating great distances (> 1000 km) before decaying below background noise. When temporal variability is small, the altimetry (plus information on ocean density) sets useful constraints on energy fluxes into internal tides. At the Hawaiian Ridge, 15 GW of tidal power is being converted from barotropic to first-mode baroclinic motion. Examples elsewhere warn that a simplistic interpretation of the altimetry, without regard to variability, noise, or in situ information, may be highly misleading. With such uncertainties, extension of the Hawaiian results into a usefully realistic estimate of the global internal-tide energy balance appears premature at this time.

Ray, Richard D.; Mitchum, Gary T.

184

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

185

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...

186

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

187

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

188

Winter Weather  

MedlinePLUS

... Matters What's New A - Z Index Disasters & Severe Weather Earthquakes Extreme Heat Floods Hurricanes Landslides Tornadoes Tsunamis Volcanoes Wildfires Winter Weather Winter Weather Language: English Español (Spanish) Recommend on Facebook Tweet ...

189

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

190

Modelling the barotropic tide along the West-Iberian margin  

NASA Astrophysics Data System (ADS)

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

Quaresma, Luis S.; Pichon, Annick

2013-01-01

191

Hydrochemical and Isotopic Constraints on the Temporal and Spatial Variability of Chemical Weathering and CO2 Fluxes: An Example From the Australian Victorian Alps  

NASA Astrophysics Data System (ADS)

Water from a network of 11 pristine rivers draining the Australian Victorian Alps was collected at different locations during (i) high discharge (June 2006) and (ii) low discharge (February 2007) conditions and was analyzed for dissolved major ions, ?2H and ?18O, and ?34S of dissolved sulphate. River water chemistry implies that solutes are largely derived from precipitation and chemical weathering of silicate lithologies. Cl/Br ratios as low as 30 molar suggest that rivers have not dissolved halite, however, higher salinity (?100 mmol/L) winter samples have intermediate Cl/Br ratios (600 to 2000 molar) that are attributed to minor halite dissolution at the onset of the rainy season. Subsequent mixing of river water homogenizes ratios and evaporation is the dominant process that increases downstream salinities. Oxygen and Hydrogen isotopes also indicate that mixing and evaporation have occurred. Despite the lack of carbonate outcrops in the study area and uniform negative calcite saturation indices, the dissolution of hydrothermal calcite may account for up to 67% of the total dissolved cations, generating up to 92% of all dissolved Ca and Mg. The sulphur isotope data (16 to 20°CDT) indicates that the dissolved SO4 is derived predominantly from atmospheric deposition and minor gypsum weathering and not from bacterial reduction of FeS. This militates against sulphuric acid weathering in Victorian rivers. Si/(Na* + K*) ratios suggest that silicate weathering is dominated by the transformation of plagioclase (An40) to smectite and, to a lesser extend, the production of kaolinite. In total, chemical weathering consumes 17.6 x 106 (summer) to 71.59 x 106(winter) mol/km2/yr CO2, with the highest values in rivers draining the basement outcrops rather than sedimentary rocks. This range is at the upper end of the global scale and shows that the predominance of fresh silicate lithologies exerts the main control on higher CO2 fluxes; temperature and runoff, in turn, are crucial variables for the inter- seasonal variability in this region. Data on discharge and major ion chemistry, measured in regular intervals between 1977 and 1990, support this; however, the timing of absolute maxima of Si/(Na* + K*) and CO2 flux peaks do not coincide. We suggest that the combination of dissolution of diatoms that precipitated under low flow- and high temperature conditions in the tributaries and Na-adsorption by suspended clay particles, that were probably redistributed locally after bushfires and/or duststorms during drought periods in the early 1980's, as mechanisms to spontaneously elevate Si/(Na* + K*) ratios and, when coupled with irregular discharge fluctuations, explain deviations from seasonal CO2 fluxes.

Hagedorn, B.; Cartwright, I.

2007-12-01

192

Solar weather/climate predictions  

NASA Technical Reports Server (NTRS)

Solar variability influences upon terrestrial weather and climate are addressed. Both the positive and negative findings are included and specific predictions, areas of further study, and recommendations listed.

Schatten, K. H.; Goldberg, R. A.; Mitchell, J. M.; Olson, R.; Schaefer, J.; Silverman, S.; Wilcox, J.; Williams, G.

1979-01-01

193

Perigean Spring Tides and Apogean Neap Tides in History  

NASA Astrophysics Data System (ADS)

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

Olson, Donald W.

2012-01-01

194

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

195

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

196

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

197

Internal tide generation at a shelf break by an oblique barotropic tide: Observations and analytical modeling  

NASA Astrophysics Data System (ADS)

An analytical model has been developed to describe the generation of a linear interfacial wave over a steep ocean margin by a barotropic tide propagating toward the shelf break with a variable angle of incidence. The stratification is reduced to a two-layer system, and the model uses step-like shelf geometry. In both shallow and deep regions an open boundary is assumed (this implies particularly that there is no reflection at the coast). The model is forced with the amplitude and direction of an incident barotropic Poincaré wave propagating toward the shelf break. With this forcing, the model gives the amplitude, direction of propagation, and wavenumber of both barotropic and baroclinic Poincaré waves transmitted onto the shelf and reflected into the deep region in the vicinity of the shelf break. After comparison with Baines' [1973] model, our model is compared with internal tide observations made in July 1996 on the Malin Shelf within the U.K. Land Ocean Interaction Study-Shelf Edge Study program. The observations are from moored thermistor chains and acoustic Doppler current profilers sited at two locations, one near the shelf break and the other 47.5 km onto the shelf. Observations at this latter mooring are not described by the generation model because of nonlinear changes and damping as the internal wave propagates through shallow water. Baroclinic displacements of the thermocline of 8 m amplitude were observed close to the shelf break, and total baroclinic energy was estimated at 2.4 J/m3 during neap tide and 3 J/m3 during spring tide. Both amplitude and energy of the shoreward propagating internal tide waves are compared with the model. Using a barotropic forcing taken from bibliographical data, good agreement with observations is found during neap tide (when the density structure is close to being two-layer) for an incident barotropic tide of 1 m amplitude and propagation direction on a bearing of 23°T (T means from True North in a clockwise sense).

Guizien, Katell; BarthéLemy, Eric; Inall, Mark E.

1999-07-01

198

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.

199

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

200

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

201

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

202

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.

203

Severe Weather  

ERIC Educational Resources Information Center

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

Forde, Evan B.

2004-01-01

204

Severe Weather  

ERIC Educational Resources Information Center

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

Forde, Evan B.

2004-01-01

205

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.

2014-09-18

206

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

207

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.

208

BBC Weather  

NSDL National Science Digital Library

At this website, the BBC offers an array of materials dealing with weather. Meteorologists can discover employment opportunities. Individuals with spectacular photographs of weather phenomenon can submit their images to the photo gallery. Students and educators can find introductory materials on basic weather concepts, forecasting, extreme events, and broadcasting the weather. The website offers fun weather-related games and projects, a meteorology glossary, and links to other educational websites.

209

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

210

The effect of weather variables on the flight activity of horseflies (Diptera: Tabanidae) in the continental climate of Hungary.  

PubMed

Although the tabanid species and populations occurring in eastern central Europe (Carpathian Basin) are thoroughly studied, there are only sporadic data about the influence of weather conditions on the abundance and activity of horseflies. To fill in this lack, in Hungary, we performed a 3-month summer survey of horsefly catches registering the weather parameters. Using common canopy traps and polarization liquid traps, we found the following: (i) rainfall, air temperature, and sunshine were the three most important factors influencing the trapping number of tabanids. (ii) The effect of relative air humidity H on tabanids was indirect through the air temperature T: H???35 % (corresponding to T???32 °C) was optimal for tabanid trapping, and tabanids were not captured for H???80 % (corresponding to T???18 °C). (iii) A fast decrease in the air pressure enhanced the trapping number of both water-seeking and host-seeking horseflies. (iv) Wind velocities larger than 10 km/h reduced drastically the number of trapped tabanids. Our data presented here may serve as a reference for further investigations of the effect of climate change on tabanids in Europe. PMID:25563609

Herczeg, Tamás; Száz, Dénes; Blahó, Miklós; Barta, András; Gyurkovszky, Mónika; Farkas, Róbert; Horváth, Gábor

2015-03-01

211

Development of Numerical Weather Prediction and Ocean Mixed Layer Model and the Prediction of Diurnal Variability of SST  

NASA Astrophysics Data System (ADS)

A numerical weather prediction (NWP)-ocean mixed layer (OML) coupled model is developed with an aim to predict the diurnal variation of SST and to improve the NWP model performance. The WRF model is used for the NWP model, and the Noh mixed layer model (Noh & Kim 1999, Noh et al. 2002) for the OML model. The model domain covers East Asia (100-150°E, 11-61°N). The mixed layer model is modified so as to realize the strong near surface stratification under calm weather (e.g., Soloviev & Rogers 1997). With an aim to examine the performance of the coupled model, the diurnal variation of SST is compared between those from the coupled-model, the regression model (Kawai & Kawamura 2005), and the satellite data (MTSAT-1R), in which a good agreement is found. Based on the comparison, the parameterization to relate the bulk SST with the skin SST is attempted. Furthermore, the mixed layer dynamics responding to the surface atmospheric forcing is investigated from the perspective of SST variation.

Lee, Eun-Jeong; Noh, Yign; Kim, Dong-Hoon

2010-05-01

212

Galalctic Tides & the Sinusoidal Potential  

NASA Astrophysics Data System (ADS)

The sinusoidal potential is a nonNewtonian alternative to dark matter. Instead of ? = -GM/r we write ? = -(GM/r) cos kor, where ko= 2?/ ?o and ?o = Ro/20= 400 pc. Evidence for this choice for the "wavelength” ?o has been given in one article and many previous meetings of the AAS & DDA. The solar system and nearby stars are trapped in a local groove of width ?r < 400 pc. The rapid alternation of attraction and repulsion within the groove gives very strong Galactic radial tides. The epicyclic period is only 7 Myr . The Keplerian period for comets in the middle of the Oort cloud is also 7 Myr. The 1:1 resonance between material in the groove and the cloud provides a new mechanism for filling the Oort cloud. The Oort cloud is emptied by the same strong radial tides. Evidence is found in the 499 comets with calculated 1/aoriginal in the latest Catalogue of Cometary Orbits (Marsden & Williams 2008). . I separate the comets into 12 classes on the basis of Quality (4 types) and semi-major axis aoriginal . For 10 of the 12 classes radial tides dominate Z-tides. The classic Oort cloud comets (1851-1996) have a particularly strong modulation with galactic longitude. This modulation is exactly in those directions where a radial tide would be important. The equally numerous recent Oort comets (1996-2008) show a different evidence for strong radial tides. The recent comets generally have much larger perihelion distances q than the classic ones. Here the evidence is that a radial tide is removing angular momentum from the orbit and thus bringing the perihelion closer to the earth and to observers.

Bartlett, David F.

2011-05-01

213

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

214

Seasonal and inter-annual variability of the net ecosystem CO2 exchange of a temperate mountain grassland: Effects of weather and management  

NASA Astrophysics Data System (ADS)

The role and relative importance of weather and cutting for the seasonal and inter-annual variability of the net ecosystem CO2 exchange (NEE) of a temperate mountain grassland was investigated. Eddy covariance CO2 flux data and associated measurements of the green plant area index and the major environmental driving forces acquired during 2001-2006 at the study site Neustift (Austria) were analyzed. Driven by three cutting events per year which kept the investigated grassland in a stage of vigorous growth, the seasonal variability of NEE was primarily modulated by gross primary productivity (GPP). The role of environmental parameters in modulating the seasonal variability of NEE was obscured by the strong response of GPP to changes in the amount of green plant area, as well as the cutting-mediated decoupling of phenological development and the seasonal course of environmental drivers. None of the environmental and management metrics examined was able to explain the inter-annual variability of annual NEE. This is thought to result from (1) a high covariance between GPP and ecosystem respiration (Reco) at the annual timescale which results in a comparatively small inter-annual variation of NEE, (2) compensating effects between carbon exchange during and outside the management period, and (3) changes in the biotic response to rather than the environmental variables per se. GPP was more important in modulating inter-annual variations in NEE in spring and before the first and second cut, while Reco explained a larger fraction of the inter-annual variability of NEE during the remaining periods, in particular the post-cut periods.

Wohlfahrt, Georg; Hammerle, Albin; Haslwanter, Alois; Bahn, Michael; Tappeiner, Ulrike; Cernusca, Alexander

2008-04-01

215

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

216

Seasonal Asymmetry in Martian Tides  

NASA Astrophysics Data System (ADS)

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

Moudden, Youssef; Forbes, Jeffrey

2014-05-01

217

Weather Report  

NSDL National Science Digital Library

This printable weather report is designed to help students easily note a field site's important meteorological details. The one-page PDF form asks for the following information: date, temperature, precipitation, weather type, and wind speed (based on environmental clues).

218

Predicting Seasonal Weather  

NSDL National Science Digital Library

Large-scale weather patterns which occur in various locations around the Earth play a significant part in controlling the weather on a seasonal time scale. A National Science Foundation (NSF)-funded collaborative research effort between Atmospheric and Environmental Research, Inc. (AER), and the Massachusetts Institute of Technology (MIT) has led to a new understanding of the relationship between fall snow cover and winter climate variability. This research has led to the development of a new seasonal forecast model.

219

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.

Michael Passow

220

Weather Forecasting  

NSDL National Science Digital Library

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

221

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.

222

Antarctic Weather  

NSDL National Science Digital Library

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

223

Antarctic Weather  

NSDL National Science Digital Library

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

2010-01-01

224

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

225

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.

226

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

227

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

228

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

229

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 Sanchez

2014-02-20

230

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

231

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.

232

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. ...

233

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

234

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

235

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

236

Severe Weather  

NSDL National Science Digital Library

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

Evan B. Forde

2004-04-01

237

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

238

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

239

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

240

Energetics of internal tides around the Kerguelen Plateau from modeling and altimetry  

NASA Astrophysics Data System (ADS)

A barotropic tidal model, with a parameterization term to account for the internal wave drag energy dissipation, is used to examine areas of possible M2 internal tide generation in the Kerguelen Plateau region. Barotropic energy flux and a distribution of wave drag dissipation are computed. The results suggest important conversion of barotropic energy into baroclinic tide generation over the northern Kerguelen Plateau shelf break, consistent with a theoretical criterion based on ocean stratification, tidal forcing frequency, and bathymetric gradients. The sea surface height signatures of time-coherent internal tides are studied using TOPEX/Poseidon and Jason-1 altimeter data, whose ascending tracks cross nearly perpendicular to the eastern and western Kerguelen Plateau shelf break. Oscillations of a few centimeters associated with phase-locked internal tides propagate away from the plateau over distances of several hundred kilometers with a ˜110 km wavelength. When reaching the frontal area of the Antarctic Circumpolar Current, the internal tide cannot be identified because of the aliasing of mesoscale variability into the same alias band as M2. Finally, using altimeter data, we estimate the M2 barotropic tidal power converted through the internal tide generation process. We find consistent values with the barotropic model parameterization estimation, which is also in good agreement with global internal tide model estimates. Combined with modeling, this study has shown that altimetry can be used to estimate internal tide dissipation.

Maraldi, Claire; Lyard, Florent; Testut, Laurent; Coleman, Richard

2011-06-01

241

On the predictability of mode-1 internal tides  

NASA Astrophysics Data System (ADS)

A frequency-wavenumber tidal analysis for deriving internal-tide harmonic constants from TOPEX/Poseidon (T/P) measurements of sea-surface height (SSH) has been developed, taking advantage of the evident temporal and spatial coherence and the weak dissipation of internal tides. Previous analyses consisted of simple tidal analysis at individual points, which gave inconsistent harmonic constants at altimeter track crossover points. Such analyses have difficulty in distinguishing between the effects of interference, incoherence, and dissipation. The frequency-wavenumber analysis provides an objective way to interpolate the internal tides measured along altimetry tracks to any arbitrary point, while leveraging all available data for optimal tidal estimates. Tidal analysis of T/P data from 2000 to 2007 is used to predict in situ time series measured during the 2001-2002 Hawaiian Ocean mixing experiment (HOME), the 1987 reciprocal tomography experiment (RTE87), and the 1991 acoustic mid-ocean dynamics experiment (AMODE), demonstrating both the temporal coherence and the lack of incoherent elements to this wave propagation. It has been conjectured that significant energy would be lost from mode-1 internal tides as they cross the 28.9°N critical latitude of parametric subharmonic instability (PSI). No apparent change in amplitude at 28.9°N was detected by this analysis, however. Further, after correcting for changes in background stratification, the amplitude of the mode-1 internal tide was found to decrease by less than 20% over the 2000 km between the Hawaiian Ridge and 40°N. A significant fraction of the variability of internal waves, that component associated with mode-1 internal tides, appears to be predictable over most of the world's oceans, using harmonic constants derived from satellite altimetry.

Dushaw, Brian D.; Worcester, Peter F.; Dzieciuch, Matthew A.

2011-06-01

242

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

243

Variable strength of forest stand attributes and weather conditions on the questing activity of Ixodes ricinus ticks over years in managed forests.  

PubMed

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; Kalko, Elisabeth K V; Renner, Swen C

2013-01-01

244

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

245

Chemical Weathering  

NSDL National Science Digital Library

This tombstone weathering lab is designed to provide students with tangible understanding of chemical weathering and weathering rates. To prepare for this lab, students will have learned in previous labs to identify common minerals and rocks and will have attended lectures about the process of chemical weathering. During the first part of the lab we travel to the city cemetery to collect data on the age and extent of chemical weathering of tombstones that are made of limestone and igneous rocks. After collecting data for ~1 hour, we return to the computer lab where students use Microsoft Excel to analyze and interpret their data. Their task is to calculate a chemical weathering rate for limestone for our region and compare that rate to those from other regions. This activity gives students experience in the process of scientific inquiry: data collection, data analysis and data interpretation. Students develop Microsoft Excel skills: writing formulas, producing charts, understanding trendlines and R2 values.

Kira Lawrence

246

Weather, Chinook, and Stroke Occurrence  

Microsoft Academic Search

Background—Changes in weather and season have been linked to stroke occurrence. However, the association has been inconsistent across stroke types. Calgary is a city in the Chinook belt and is subject to high variability in weather conditions. Methods—We obtained hourly weather data over a 5-year period from 1996 to 2000; Chinook events were identified according to the accepted definition. We

Thalia S. Field; Michael D. Hill

2010-01-01

247

Weather Data  

NSDL National Science Digital Library

The listed websites are recommended safe kid friendly sites that may be used when gathering data for the at home data project. Use the websites listed to learn more about daily weather patterns in different cities around the world. After you have collected and organized your data, create a graph representing the different weather patterns in that city. Use this site to record the daily high temperature for your assigned city. The Weather Channel Use this ...

Ms. Harris

2011-01-24

248

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.

249

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.

250

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.

R. Hopson

251

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

252

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

253

Assessing the role of spatial rainfall variability on watersheds response using weather radar A case study in the Gard region, France  

NASA Astrophysics Data System (ADS)

The consideration of spatial rainfall variability in hydrological modeling is not only an important scientific issue but also, with the current development of high resolution rainfall data from weather radars, an increasing request from managers of sewerage networks and from flood forecasting services. Although the literature on this topic is already significant, at this time the conclusions remain contrasted. The impact of spatial rainfall variability on the hydrological responses appears to highly depend both on the organization of rainfall fields and on the watershed characteristics. The objective of the study presented here is to confirm and analyze the high impact of spatial rainfall variability in the specific context of flash floods. The case study presented is located in the Gard region in south east of France and focuses on four events which occurred on 13 different watersheds in 2008. The hydrological behaviors of these watersheds have been represented by the distributed rainfall - runoff model CINECAR, which already proved to well represent the hydrological responses in this region (Naulin et al., 2013). The influence of spatial rainfall variability has been studied here by considering two different rainfall inputs: radar data with a resolution of 1 km x 1 km and the spatial average rainfall over the catchment. First, the comparison between simulated and measured hydrographs confirms the good performances of the model for intense rainfall events, independently of the level of spatial rainfall variability of these events. Secondly, the simulated hydrographs obtained from radar data are taken as reference and compared to those obtained from the average rainfall inputs by computing two values: the time difference and the difference of magnitude between the simulated peaks discharge. The results highly depend on the rainfall event considered, and on the level of organization of the spatial rainfall variability. According to the model, the behavior of the studied watersheds may sometimes remain very similar with a homogeneous rainfall input, whereas for some cases the differences in the peak discharges can reach up to 80%. A detailed analysis illustrates the possible role of the watershed in enhancing the effect of rainfall spatial variability. In a further step, the objective is to test the ability of four rainfall variability indicators to identify the situations for which spatial rainfall variability has the greatest influence on the watershed response. The selected indicators include those of Zoccatelli et al. (2010), and all rely on a detailed analysis of spatial rainfall organization in function of hydrological distances (i.e. the distances measured along the stream network from one point of the watershed to the outlet). The analysis of the links between these indicators and the hydrological behaviors identified is currently in progress. Reference: Naulin, J.P., Payrastre, O., Gaume, E., 2013. Spatially distributed flood forecasting in flash flood prone areas: Application to road network supervision in Southern France. Journal of Hydrology, 486, 88-99, doi:10.1016/j.jhydrol.2013.01.044 Zoccatelli, D., Borga, M., Zanon, F., Antonescu, B., Stancalie, G., 2010. Which rainfall spatial information for flash flood response modelling? A numerical investigation based on data from the Carpathian range, Romania. Journal of Hydrology, 394, 148-161

Anggraheni, Evi; Payrastre, Olivier; Emmanuel, Isabelle; Andrieu, Herve

2014-05-01

254

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

255

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

256

ATMOSPHERIC TIDES RICHARD S. LINDZEN  

E-print Network

Daily Variations 1.2A. True or Apparent Time, and Mean Time 1.2B. The Harmonic Dial 1.3. Thermal Tides-Cyclic Variation 2S.3. The Seasonal Variation of S 2S.3A. Daily Seasonal Integers a (Sigma) or SN(Bartels, 1954) 2S(p) 2S.5. The Daily Variation of Air Temperature T 2S.6. The Daily Wind Variation S(V) * The National

Lindzen, Richard S.

257

Toxic Blooms: Understanding Red Tides  

NSDL National Science Digital Library

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

Dr. Don Anderson

258

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.

259

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

260

Weather Instruments.  

ERIC Educational Resources Information Center

This booklet presents some activities to measure various weather phenomena. Directions for constructing a weather station are included. Instruments including rain gauges, thermometers, wind vanes, wind speed devices, humidity devices, barometers, atmospheric observations, a dustfall jar, sticky-tape can, detection of gases in the air, and pH of…

Brantley, L. Reed, Sr.; Demanche, Edna L.; Klemm, E. Barbara; Kyselka, Will; Phillips, Edwin A.; Pottenger, Francis M.; Yamamoto, Karen N.; Young, Donald B.

261

Weather Forecasting  

NSDL National Science Digital Library

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

Twin Cities Public Television, Inc.

2005-01-01

262

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.

263

Climatology of the migrating terdiurnal tide (TW3) in SABER/TIMED temperatures  

NASA Astrophysics Data System (ADS)

The present paper is focused on the global spatial (altitude and latitude) structure and seasonal and interannual temporal variability of the migrating terdiurnal tide (TW3) seen in 8 years (2002-2009) of observations of the kinetic temperature measured by the SABER instrument on the TIMED satellite. The tides (migrating and nonmigrating) and the planetary waves (zonally traveling and stationary) are simultaneously extracted from the satellite data. It is found that the SABER TW3 tide is dominated by different Hough modes below and above ~80 to 90 km height; in the mesosphere, it reflects mainly the evanescent feature of the first symmetric mode, and in the lower thermosphere, propagating modes with shorter vertical wavelengths dominate its structure. The seasonal behavior of the terdiurnal tide at low latitudes is dominated by an annual variation with local summer amplification, while that at midlatitudes is a combination of semiannual variation with maxima in equinoxes and an annual variability with winter enhancement. The Hough modes of the solar heating from WACCM heating to a large extent determine the predominantly antisymmetric features of the SABER TW3 tide during the solstice but are not able to explain well the predominant symmetric features in the equinoxes. The TW3 tide reveals some interannual variability with a period of quasi-2 years which indicates an enhancement during the eastward phase of the stratospheric QBO.

Pancheva, D.; Mukhtarov, P.; Smith, A. K.

2013-04-01

264

Titan's Eccentricity Tides  

NASA Astrophysics Data System (ADS)

The large eccentricity (e=0.03) of Titan's orbit causes significant variations in the tidal field from Saturn and induces periodic stresses in the satellite body at the orbital period (about 16 days). Peak-to-peak variations of the tidal field (from pericenter to apocenter) are about 18% (6e). If Titan hosts a liquid layer (such as an internal ocean), the gravity field would exhibit significant periodic variations. The response of the body to fast variations of the external, perturbing field is controlled by the Love numbers, defined for each spherical harmonic as the ratio between the perturbed and perturbing potential. For Titan the largest effect is by far on the quadrupole field, and the corresponding Love number is indicated by k2 (assumed to be identical for all degree 2 harmonics). Models of Titan's interior generally envisage a core made up of silicates, surrounded by a layer of high pressure ice, possibly a liquid water or water-ammonia ocean, and an ice-I outer shell, with variations associated with the dehydration state of the core or the presence of mixed rock-ice layers. Previous analysis of Titan's tidal response [1] shows that k2 depends crucially on the presence or absence of an internal ocean. k2 was found to vary from about 0.03 for a purely rocky interior to 0.48 for a rigid rocky core surrounded by an ocean and a thin (20 km) ice shell. A large k2 entails changes in the satellite's quadrupole coefficients by a few percent, enough to be detected by accurate range rate measurements of the Cassini spacecraft. So far, of the many Cassini's flybys of Titan, six were used for gravity measurements. During gravity flybys the spacecraft is tracked from the antennas of NASA's Deep Space Network using microwave links at X- and Ka-band frequencies. A state-of-the-art instrumentation enables range rate measurements accurate to 10-50 micron/s at integration times of 60 s. The first four flybys provided the static gravity field and the moment of inertia factor of the body[2]. In this previous analysis, tidal variations of the gravity field were neglected. Thanks to the availability of two additional flybys (on May 20, 2010 and Feb. 18, 2011) and the improvement of the data analysis tools, also the variable component of the gravity field could be estimated with good accuracy. In order to increase the confidence in the results, two independent analyses have been carried out, both resulting in very close and statistically indistinguishable values for k2. While the results are compatible (at the low end of k2) with interior models made up by a high viscosity core and a near-surface liquid water layer, the centroid of the k2 values requires additionally that some substantial fraction of the interior -ice mantle or core- be capable of significant deformations over time scales of the orbital period. References [1] Rappaport, N.J. et al., 2008. Can Cassini detect a subsurface ocean in Titan from gravity measurements?, Icarus, Vol. 194, No. 2. [2] Iess, L. et al., 2010. Gravity field, shape, and moment of inertia of Titan. Science 327, 1367-1369.

Iess, L.; Jacobson, R.; Ducci, M.; Stevenson, D. J.; Lunine, J. I.; Armstrong, J. W.; Asmar, S.; Racioppa, P.; Rappaport, N. J.; Tortora, P.

2011-12-01

265

The pole tide in deep oceans  

NASA Technical Reports Server (NTRS)

The fluid-dynamical theory of the pole tide is examined by describing the oceanic response to the Chandler wobble and assessing its implications for mantle anelasticity and low-frequency ocean dynamics. The Laplace tide equations accounting for bottom friction are given, and a spherical harmonic approach is delineated in which the time-independent portion of the tide height is expanded. Pole-tide height and related inertia products are linearly proportional to wobble amplitude, and the final equations are modified to account for mantle elasticity and oceanic loading. Results for pole tide effects are given for various earth models with attention to the role of boundary constraints. A dynamic effect is identified which lengthens the Chandler period by about 1 day more than static lengthening, a contribution that suggests a vigorous low-frequency response. The values derived are shown to agree with previous models that do not incorporate the effects of the pole tide.

Dickman, S. R.

1990-01-01

266

A weather-type conditioned multi-site stochastic rainfall model for the generation of scenarios of climatic variability and change  

E-print Network

A weather-type conditioned multi-site stochastic rainfall model for the generation of scenarios 29 October 2004 Abstract Further developments of a stochastic rainfall model conditioned by weather rainfall cross-correlation between two sub-regional Neyman­Scott Rectangular Pulses (NSRP) rainfall models

Fowler, Hayley

267

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.

John Nielsen-Gammon

1996-09-01

268

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

269

Tides in the Strait of Gibraltar  

NASA Astrophysics Data System (ADS)

The Strait of Gibraltar is where the transition occurs between two distinct tidal regimes: the North Atlantic, where tidal ranges are in excess of 2 m, and the western Mediterranean, where tidal ranges are less than 1 m. Within the strait the tide is principally semidiurnal: observations indicate that on average, 96% of the bottom pressure and 74% of the current variability are contained in the semidiurnal band (2 cpd). The structure of the local cotidal chart of the M2 tidal constituent is complicated but can be explained in terms of the along- and across-strait momentum balances. Along the strait, the pressure gradient is mainly balanced by the acceleration of the flow, although friction can be of appreciable magnitude, corresponding to a decay time scale of 3-16 hours. Across the strait the momentum balance appears mostly geostrophic, but better observations would be required to explain residual terms. Available observations indicate that the M2 tide has no net energy flux through the strait. At the sill the tidal transport in the upper layer exceeds that in the lower layer by nearly a factor of 2. At the eastern end of the strait, between Algeciras and Ceuta, the tidal transport is larger in the lower layer. This apparent shift in the location of maximum tidal transport is explained in terms of the kinematics of the interface between Atlantic and Mediterranean waters. A mean transport of 0.21 Sv, due to subinertial and tidal flows, carries Atlantic water through the strait, compensated by an approximately equal return in the lower layer.

Candela, Julio; Winant, Clinton; Ruiz, Antonio

1990-05-01

270

Planetary Weather  

NSDL National Science Digital Library

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

271

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

272

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

273

Weather One  

NSDL National Science Digital Library

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

Duane Friend

274

Winter Weather  

MedlinePLUS

... weather presents hazards including slippery roads/surfaces, strong winds and environmental cold. Employers must prevent illnesses, injuries, ... from surfaces) Use extreme caution when working near power lines Prevent harmful exposure to cold temperatures and ...

275

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

276

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

277

Weather Maps  

NSDL National Science Digital Library

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

278

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

279

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

280

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.

Pete Stelling

281

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.

2012-06-26

282

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

283

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

284

Incoherent Scatter Radar Study of Atmospheric Tides in the Low Latitude Thermosphere  

NASA Astrophysics Data System (ADS)

Atmospheric tides are one of the most important driving forces in atmospheric circulation and energy exchange. An extensive analysis of atmospheric tides and their impact on the ionosphere in the low latitude thermosphere is presented. The analysis is based on observational data from the Arecibo dual-beam incoherent scatter radar during January 14-23 in 2010. The vertical structure and variability of the diurnal, semidiurnal tides, and high-frequency tidal components in the thermosphere for winter conditions have been revealed. Additionally, the F-region tidal response to the SSW event is discussed for the first time in the low latitude. Important findings of the present study are as follows. (1) Varying from prior observational studies, the diurnal tide in the meridional wind is prominent at F-region. The diurnal tide with an evanescent phase structure has a peak amplitude of 45 m/s occurring at about 245 km and it is very stable throughout the nine consecutive days’ observation. In the E-region, the diurnal tide in the meridional wind is very substantial. Its amplitude can reach 70 m/s. Below 114 km, the vertical structures of the diurnal tide in the meridional and zonal components are consistent, which resemble the classical solar S1, 1 tidal mode. (2) In the F-region, semidiurnal amplitude is much weaker and has larger interval-to-interval variability compared with diurnal amplitude. In the E-region, The semidiurnal tides show constant increase of amplitude in the altitude range from 106 km to 121 km in the meridional wind and from 100 km to 115 km in the zonal wind. The vertical wavelength of the zonal component is estimated as 45 km above 100 km, which is close to the solar S2, 4 and S2, 5 tidal modes.

Gong, Yun; Zhou, Qihou; Zhang, Shao dong

285

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

286

Internal tide radiation from the Luzon Strait  

NASA Astrophysics Data System (ADS)

The 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

287

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

288

Weather from the Stratosphere?  

NASA Technical Reports Server (NTRS)

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

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

2006-01-01

289

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

290

The Art of Red Tide Science.  

PubMed

Over the years, numerous outreach strategies by the science community, such as FAQ cards and website information, have been used to explain blooms of the toxic dinoflagellate, Karenia brevis that occur annually off the west coast of Florida to the impacted communities. Many state and federal agencies have turned to funded research groups for assistance in the development and testing of environmental outreach products. In the case of Florida red tide, the Fish and Wildlife Research Institute/Mote Marine Laboratory (MML) Cooperative Red Tide Agreement allowed MML to initiate a project aimed at developing innovative outreach products about Florida red tide. This project, which we coined "The Art of Red Tide Science," consisted of a team effort between scientists from MML and students from Ringling College of Art and Design. This successful outreach project focused on Florida red tide can be used as a model to develop similar outreach projects for equally complex ecological issues. PMID:22712002

Hall, Emily R; Nierenberg, Kate; Boyes, Anamari J; Heil, Cynthia A; Flewelling, Leanne J; Kirkpatrick, Barbara

2012-05-01

291

The Art of Red Tide Science  

PubMed Central

Over the years, numerous outreach strategies by the science community, such as FAQ cards and website information, have been used to explain blooms of the toxic dinoflagellate, Karenia brevis that occur annually off the west coast of Florida to the impacted communities. Many state and federal agencies have turned to funded research groups for assistance in the development and testing of environmental outreach products. In the case of Florida red tide, the Fish and Wildlife Research Institute/Mote Marine Laboratory (MML) Cooperative Red Tide Agreement allowed MML to initiate a project aimed at developing innovative outreach products about Florida red tide. This project, which we coined “The Art of Red Tide Science,” consisted of a team effort between scientists from MML and students from Ringling College of Art and Design. This successful outreach project focused on Florida red tide can be used as a model to develop similar outreach projects for equally complex ecological issues. PMID:22712002

Hall, Emily R.; Nierenberg, Kate; Boyes, Anamari J.; Heil, Cynthia A.; Flewelling, Leanne J.; Kirkpatrick, Barbara

2012-01-01

292

The Weather Doctor  

NSDL National Science Digital Library

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

Heidorn, Keith.

293

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

294

Wonderful Weather  

NSDL National Science Digital Library

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

Ms. Broadhead

2007-11-06

295

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.

296

Weather Forecasting  

NSDL National Science Digital Library

In this online, interactive module, students will learn how to interpret weather patterns from satellite images, predict storm paths and forecast the weather for their area. 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.

297

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. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. Why does the wind blow? 2. When winds are blowing, how can you get them to stop? 3. What happens when the temperature is the same? 4. What happens when there is high relative humidity? 5. What ...

missy.jones@gmail.com

2009-09-28

298

North Atlantic Climate Variability: Preliminary Analysis of Historical Weather Data and Stable Isotope Time Series of Cave Dripwater and Holocene-Age Stalagmites from Bermuda  

NASA Astrophysics Data System (ADS)

Bermuda, located in the center of the Sargasso Sea of the North Atlantic Ocean, is a unique laboratory for analyzing Holocene climate change. This subtropical area lacks a strong seasonal cycle, making it an ideal place to look for low-frequency cycles identified in observational records of North Atlantic climate. A preliminary statistical analysis of historical climate data, provided by the Bermuda Weather Service and spanning a period from 1852 to 2006, will be presented. Emphasis will be placed on the identification of cycles corresponding to such climate modes as the North Atlantic Oscillation (NAO) and the Atlantic Multidecadal Oscillation (AMO). To extend the record back farther than the observational period, it is necessary to identify and analyze paleoclimate proxies. Carbonate caves on the island of Bermuda contain numerous speleothems, which have the potential to serve as extremely high-resolution (sub-decadal) recorders of climate change via the stable oxygen and carbon isotope concentrations contained in their crystalline form. Stalagmite stable isotope data is reflective of changes in stable isotopes of the cave dripwater feeding the stalagmite. Approximately monthly time series of ?18O data from three dripwater sites in each of two Bermuda caves, Fantasy Cave and Leamington Cave, will be presented, covering the period from April 2006 to March 2008. Values from Fantasy Cave range from -4.7 permil to -3.0 permil. Interestingly, a positive excursion of ~0.8 permil in the dripwater ?18O is associated with the passage of Hurricane Florence over the island in September 2006; possible causes of this spike include a change in vapor source or hurricane wind-induced sea spray. The dripwater data will help us to calibrate and interpret the stable isotope data from stalagmite calcite in our samples. Several stalagmites retrieved from caves in the Hamilton Parish region of Bermuda were dated by U-series methods and found to cover a period from 4.7 thousand years ago to the present. Time series of stable isotope data (?18O and ?13C) from these stalagmites will be presented. Initial results from one stalagmite, covering approximately 4150-2600 years ago, show a range of -4.0 permil to -1.5 permil in ?18O, and -9.0 permil to -3.5 permil in ?13C. Analysis and discussion of this data will include implications for the dominant modes of North Atlantic climate variability over the last 4.7 thousand years.

Gaurin, S. E.; Burns, S. J.; Woodworth, M.; Wood, J.; Edwards, L.; Cheng, H.

2008-12-01

299

Internal tides in Dixon Entrance  

NASA Astrophysics Data System (ADS)

Semidiurnal (M2) internal tides are studied in and near Dixon Entrance. Two complementary approaches are presented: a data analysis and a numerical study. the data consist of current records as well as hydrographic profiles. The derived baroclinic velocities represent a considerable portion of the total signal. The baroclinic velocities change little in time and variations in the vertical suggest the presence of a vertical mode. A nonlinear, frictionless, two-layer, finite-difference numerical model forced by a barotropic tidal wave was applied over an idealized topography representing Dixon Entrance. Specifically, Dixon Entrance was modelled as a coastal east-west oriented, shallow channel connected to a deep flat open ocean through a very steep continental slope. Several numerical experiments are presented. The main result the model offers is a possible explanation, in terms of waves, of the generation of internal tides. The passage of long barotropic Kelvin waves travelling north on the the open ocean triggers a baroclinic diffraction process which gives rise to cylindrical Poincare waves travelling towards the deep ocean, westward, Kelvin waves propagating along the coast, northward, and Kelvin waves propagating inside the channel, eastward. This wave pattern was described by Buchwald (1971). The Kelvin wave pattern always seems to be present inside the channel; however, internal waves are very sensitive to variations in the topography, and waves of short wavelengths are also generated. It was possible from the numerical experiments to explain some of the features found in the data analysis. The velocity magnitudes and main generation regions were comparable. The results of the model were unable to explain the detail of the quasi-steady pattern of baroclinic currents.

Carrasco, Ana Consuelo

1998-11-01

300

The Application of Synoptic Weather Forecasting Rules to Selected Weather Situations in the United States.  

ERIC Educational Resources Information Center

The document describes the use of weather maps and data in teaching introductory college courses in synoptic meteorology. Students examine weather changes at three-hour intervals from data obtained from the "Monthly Summary of Local Climatological Data." Weather variables in the local summary include sky cover, air temperature, dew point, relative…

Kohler, Fred E.

301

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

302

Space Weather  

E-print Network

Space Weather :: Printer Friendly Version of Article 2005SW000176 http://www.agu.org/journals/sw/swa/feature/article/print.php?id=2005S... 1 of 5 07/07/2006 12:22 PM Shielding Space Explorers From Cosmic Rays Expert opinions-inducing radiation in space. Eugene N. Parker 18 August 2005 Any space traveler far removed from the protective

Shepherd, Simon

303

Weathering Experiments  

NSDL National Science Digital Library

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

304

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.

2012-12-19

305

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

306

Weather Alert  

NSDL National Science Digital Library

Students discuss the characteristics of storms, including the relationship of weather fronts and storms. Using everyday materials, they develop models of basic lightning detection systems (similar to a Benjamin Franklin design) and analyze their models to determine their effectiveness as community storm warning systems.

Integrated Teaching and Learning Program,

307

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

308

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.

309

Diurnal tides in the Arctic Ocean  

NASA Technical Reports Server (NTRS)

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

Kowalik, Z.; Proshutinsky, A. Y.

1993-01-01

310

Florida Red Tide Perception: Residents versus Tourists.  

PubMed

The west coast of Florida has annual blooms of the toxin-producing dinoflagellate, Karenia brevis with Sarasota, FL considered the epicenter for these blooms. Numerous outreach materials, including Frequently Asked Question (FAQ) cards, exhibits for local museums and aquaria, public beach signs, and numerous websites have been developed to disseminate information to the public about this natural hazard. In addition, during intense onshore blooms, a great deal of media attention, primarily via newspaper (print and web) and television, is focused on red tide. However to date, the only measure of effectiveness of these outreach methods has been counts of the number of people exposed to the information, e.g., visits to a website or number of FAQ cards distributed. No formal assessment has been conducted to determine if these materials meet their goal of informing the public about Florida red tide. Also, although local residents have the opinion that they are very knowledgeable about Florida red tide, this has not been verified empirically. This study addressed these issues by creating and administering an evaluation tool for the assessment of public knowledge about Florida red tide. A focus group of Florida red tide outreach developers assisted in the creation of the evaluation tool. The location of the evaluation was the west coast of Florida, in Sarasota County. The objective was to assess the knowledge of the general public about Florida red tide. This assessment identified gaps in public knowledge regarding Florida red tides and also identified what information sources people want to use to obtain information on Florida red tide. The results from this study can be used to develop more effective outreach materials on Florida red tide. PMID:20824108

Nierenberg, Kate; Byrne, Margaret; Fleming, Lora E; Stephan, Wendy; Reich, Andrew; Backer, Lorraine C; Tanga, Elvira; Dalpra, Dana R; Kirkpatrick, Barbara

2010-09-01

311

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.

312

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

313

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

314

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

315

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

316

National Weather Service  

MedlinePLUS

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

317

Activities in Teaching Weather  

ERIC Educational Resources Information Center

Presented is a unit composed of activities for teaching weather. Topics include cloud types and formation, simple weather instruments, and the weather station. Illustrations include a weather chart and instruments. A bibliography is given. (MA)

Tonn, Martin

1977-01-01

318

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

319

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

320

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.

321

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.

322

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 ...

Mrs. Mitchell

2010-09-23

323

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,

324

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

325

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

326

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

327

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.

328

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

329

The internal tide off Panama City, Florida  

E-print Network

June 1963 Ma)or Sub)ect: Physical Oceanography THE INTERNAL TIDE OFF PANAMA CITY, FLORIDA A Thesis By Noel E. J. Boston Approved as to style and content by: a an o t e omm ttee a o t e epartm June 1963 856088 ACKNOWLEDGMENTS The work... COLLECTION. 12 1. June 1962 Survey. 2. July-September 1962 Schedule. . . . 3. Equipment and Procedures. . . . . . . . A. Temperature measurements. . B. Salinity measurements. . . . . C. Current measurements. . . . . . D. Tide measurements...

Boston, Noel Edward James

1963-01-01

330

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

331

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

332

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

333

Diurnal variation of texas “brown tide” (aureoumbra lagunensis) in relation to metals  

Microsoft Academic Search

The diurnal variability of Aureoumbra lagunensis, dissolved metals (Cd, Pb, Mn, Cr, Cu, Zn, Ni, Se, and Fe), and environmental parameters (salinity, temperature, turbidity, pH, and dissolved oxygen) were studied to understand the role of metals in the occurrence of the Texas “brown tide.” The A. lagunensis densities were high in the afternoon; suggesting the influence of light on the

V. K. Sharma; K. B. Rhudy; F. J. Millero

2000-01-01

334

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

335

Destructive Weather  

NSDL National Science Digital Library

What are the effects of different types of destructive weather? Learn All About Hurricanes Record on your chart 3 things that you learned. Watch a Hurricane Video These are the devastating Effects of Hurricanes Learn All About Tornadoes Record on your chart 3 things that you learned. Watch a Tornado Video These are the devastating Effects of tornadoes Learn All About Thunderstorms Record on your chart 3 things that you learned. These are the devastating Effects of thunderstorms Follow these important tips To keep safe. ...

alizabethirwin

2010-11-03

336

Weather Photography  

NSDL National Science Digital Library

Ph.D. student Harald Edens describes himself as a "photographer of lightning, clouds, atmospheric optical phenomena and astronomy". His Web site entitled Weather Photography proves this by providing a stunning collection of photographs and movies of atmospheric optics, lightning, clouds, and astronomy. The author describes how the photographs were taken, what equipment was used, and even discusses many of the phenomenon being observed such as mirages and halos. An added bonus of this very interesting site is that the author generously allows free personal use of the photographs.

337

Weather Activities  

NSDL National Science Digital Library

This entertaining, interactive website is the perfect tool to educate users about the basics of weather forecasting and reporting. The two educational modules, created by EdHeads, each contain three levels and are designed for grades four through nine. While discovering how to predict a three-day forecast, students learn about warm and cold fronts, wind direction and speed, high and low pressure systems, isobars, and humidity. Teachers can find a helpful guide discussing how best to use the site as well as providing an overview of science standards, lesson plans, and pre- and post-tests for students.

338

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.

339

Impacts of internal tides on acoustic propagation at sonar frequencies and their effects on sonar system performance  

NASA Astrophysics Data System (ADS)

Temperature oscillations triggered by ocean tides can be found along nearly all shelf-slope regions throughout the world's oceans. It is of interest to ascertain how these internal tides impact acoustic propagation for operational purposes. Internal tides have been observed around the Hawaiian Islands, and these tides result in large fluctuations in temperature on a semidiurnal basis. Ocean models are presented that reproduce tidally induced sound speed variations (through model-predicted variations in temperature and salinity) around the islands of Oahu and Kauai, Hawaii. The model provides sound-speed structure and variability, and this is used as input to acoustic propagation models. Model-predicted sound-speed structures are functions of space and time. We present results of studies carried out to investigate the effect of the internal tides on the performance of sonar systems. We quantify these effects by studying the impact of internal tides on factors such as the detection range to target in active systems and source localization errors in passive systems. A means of quantifying uncertainty in the performance of the sonar systems due to the presence of the internal tides is investigated by studying the performance of the sonar system by varying the strength of the internal tidal field.

Rajan, Subramaniam D.; Lewis, James K.; Rudzinsky, Jason; Stein, Peter J.

2002-05-01

340

The impact of tides on mixing and freshwater export in the Laptev Sea  

NASA Astrophysics Data System (ADS)

The vast and shallow Laptev Sea shelf is seasonally ice covered and receives large amounts of freshwater runoff from the Lena River. This shelf is an important export region for sea ice and freshwater to the Arctic basin, and features strong vertical and horizontal gradients which separate the saline basin waters from the fresh coastal waters. Processes promoting shear instabilities and diapycnal mixing are therefore of interest for physical and biogeochemical properties. The Laptev Sea shelf features considerable shear in under-ice currents largely dominated by the baroclinicity in semidiurnal tides. We present an investigation into semidiurnal tides based on year-round oceanographic moorings from different locations across the Laptev Sea shelf. Harmonic analysis of ADCP records shows a strong depth-dependence in the clockwise tidal currents that can be linked to stratification and further shows large spatial and seasonal variability of tides. Total current magnitudes are stronger on the outer than on the inner shelf, and tides overall explain >80% of the current's variance throughout the year. On the inner shelf, tides play a comparatively greater role under sea ice (40-70%) than during open water periods (20-50%) when wind-induced inertial motions dominate. The ADCP records are further complemented by two cross-shelf microstructure transects which show episodes of intense turbulent kinetic energy dissipation in the pycnocline following the alignment of the semidiurnally rotating shear-vector and the surface forcing, hence underlining the potential influence of tides on diapycnal mixing. Our results highlight the potential of tides to vertically transport freshwater, heat and nutrients, and provide some first order insights into how the physical environment of this shelf may change with changing sea ice conditions.

Janout, Markus; Lenn, Yueng-Djern

2013-04-01

341

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

342

Building a Weather-Ready Nation Winter Weather Safety  

E-print Network

Building a Weather-Ready Nation Winter Weather Safety NOAA/NWS Winter Weather Safety Seasonal Campaign www.weather.gov #12;Building a Weather-Ready Nation Winter Weather Hazards Winter Weather Safety www.weather.gov · Snow/Ice · Blizzards · Flooding · Cold Temperatures #12;Building a Weather

343

Titan's Exotic Weather  

NASA Astrophysics Data System (ADS)

Images of Titan, taken during the joint NASA and European Space Agency Cassini-Huygens mission, invoke a feeling of familiarity: washes wind downhill to damp lakebeds; massive cumuli form and quickly dissipate, suggestive of rain; and dark oval regions resemble lakes. These features arise from Titan's unique similarity with Earth: both cycle liquid between their surfaces and atmospheres, but in Titan's cool atmosphere it is methane that exists as a gas, liquid, and ice. While Titan enticingly resembles Earth, its atmosphere is 10 times thicker, so that its radiative time constant near the surface exceeds a Titan year, and prohibits large thermal gradients and seasonal surface temperature variations exceeding 3K. Titan also lacks oceans - central to Earth's climate - and instead stores much of its condensible in its atmosphere. As a result, Titan's weather differs remarkably from Earth's. Evidence for this difference appears in the location of Titan's large clouds, which frequent a narrow band at 40S latitude and a region within 30 latitude of the S. Pole. Ground-based and Cassini observations, combined with thermodynamic considerations, indicate that we are seeing large convective cloud systems. Detailed cloud models and general circulation models further suggest that these are severe rain storms, which will migrate with the change in season. Outside these migrating "gypsy" cloud bands, the atmosphere appears to be calm, humid and thus frequented by thin stratiform clouds. An intriguingly alien environment is predicted. Yet, the combined effects of Titan's patchy wet surface, atmospheric tides, possible ice volcanoes, and detailed seasonal variations remain unclear as we have witnessed only one season so far. This talk will review observations of Titan's lower atmosphere and modeling efforts to explain the observations, and explore the questions that still elude us.

Griffith, Caitlin A.

2006-09-01

344

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

345

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

346

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

347

Non-stationary internal tides observed with satellite altimetry  

NASA Astrophysics Data System (ADS)

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

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

2011-09-01

348

Tide: The Integrated Development Environment for Tropomi  

NASA Astrophysics Data System (ADS)

TIDE (formerly named IDEE) is an instrument performance evaluation tool computing Level 2 products for TROPOMI (Tropospheric Monitoring Instrument). TROPOMI is a trace gas spectrograph in the UV-SWIR wavelength range meant to detect a.o. NO2, CH4, CO and O3, for ESA's Sentinel-5 Precursor satellite. Next to measuring development of the stratospheric ozone, the instrument is especially suitable to measure boundary layer trace gases because of the high sensitivity to low altitudes for these wavelengths. The TROPOMI Integrated Development Environment (TIDE) enables System Engineering trade-offs up to Level 2 products. Because these trade-offs include several partners, they are conventionally quite time consuming. TIDE makes this process much more efficient. It thereby opens the possibility to optimize Level 1b of instrument hardware requirements during the development cycle. We do not expect these requirements will be skipped but it is possible to more rationally and more efficiently discuss and decide on them.

de Vries, J.; Plevier, C.; Beerthuizen, P.

2009-05-01

349

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

350

Thermal Tides in Short Period Exoplanets  

E-print Network

Time-dependent insolation in a planetary atmosphere induces a mass quadrupole upon which the stellar tidal acceleration can exert a force. This "thermal tide" force can give rise to secular torques on the planet and orbit as well as radial forces causing eccentricity evolution. We apply this idea to the close-in gas giant exoplanets ("hot Jupiters"). The response of radiative atmospheres is computed in a hydrostatic model which treats the insolation as a time-dependent heat source, and solves for thermal radiation using flux-limited diffusion. Fully nonlinear numerical simulations are compared to solutions of the linearized equations, as well as analytic approximations, all of which are in good agreement. We find generically that thermal tide density perturbations {\\it lead} the semi-diurnal forcing. As a result thermal tides can generate asynchronous spin and eccentricity. Our results are as follows: (1) Departure from synchronous spin is significant for hot Jupiters, and increases with orbital period. (2) O...

Arras, Phil

2009-01-01

351

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

352

'NATCOVAR' future weather patterns for crop simulation models  

NASA Astrophysics Data System (ADS)

The dissertation presents a series of pre-defined future weather patterns for the GOSSYM cotton simulation model. The weather patterns are developed by using a long-term weather data set for one given location. These daily weather patterns are designed and built based upon a statistical normal conditions, six other hypothesized abnormal weather scenarios for each variable, and one comprehensive normal condition for all weather variables. The weather patterns built by this technical approach differs from the previous methods in many ways. The main advantage of this approach is that the variables in each weather pattern maintain the properties of daily and seasonal climatic distributions, and other statistical characteristics. These patterns also significantly preserve the natural covariance among weather variables ('NATCOVAR' future weather patterns). One sensitivity test is conducted to evaluate responses of the COSSYM cotton simulation model to the variations of those desired future weather patterns, different soil types and varieties, and several cultural practices. This sensitivity test indicates the responses of the GOSSYM model by simulating plant heights and lint yields to changes in weather variables. The results of yield predictions reasonably reveal the effect of each weather variable, and interactive effects among five variables. A software package, Weather Service Tool, is designed and written in the Borland C++ programming language. It provides the necessary tool for crop modeling users to build or update local future weather inputs. The system improved the accessibility and initialization of climatic data. With a user-friendly Windows interface, this computer program simplifies and automates many of the repetitive tasks on textural inputs and selections of initial input files. The tool also improves the usability of historical climatic data for agricultural applications.

Wang, Xiaoyuan

353

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

354

A Model for Teaching the Dynamical Theory of Tides.  

ERIC Educational Resources Information Center

The dynamical theory of tides is often neglected in teaching oceanography because students have difficulty in visualizing the movements of the tides across the glove. A schematic diagram portraying amphidromic systems as mechanical gears helps overcome these problems. (Author)

Railsback, L. Bruce

1991-01-01

355

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

356

A low-dimensional hillslope and catchment runoff model based on a subsurface variable-source area hypothesis with weathered bedrock groundwater  

NASA Astrophysics Data System (ADS)

Recent field studies have reported that groundwater in weathered bedrock underlying mountainous hillslopes plays a key role in baseflow and storm flow dynamics. On the other hand, many hillslope runoff models and catchment models composed with the hillslope building units treat the soil-bedrock boundary as essentially impermeable. The inadequate modeling may limit the capability of appropriately simulating rainfall-runoff processes and also understanding effects of the groundwater surface-water interaction in mountainous regions. In this study, we conceptualized the hillslope as permeable bedrock with an overlaying soil layer, and proposed a hillslope model that can easily extend to the catchment scale. The model assumes the exponential-decline hydraulic conductivity in the bedrock to avoid defining the unknown bottom boundary. For the soil layer, it employs a stage-discharge relationship to represent the unsaturated and saturated subsurface flows and the saturation excess overland flow. The set of equations used in this study resembles the one-dimensional Boussinesq equation after introducing the Dupuit-Forchheimer assumption. In the analysis of the simulation results, we primarily focused on the Brutsaert and Nieber recession plot (i.e., Q - dQ/dt relationship) to investigate the recession characteristics. Both hillslope- and catchment-scale results suggested that the bedrock layer creates a non-linear shape in the recession curve, which is similar to the solution of the one-dimensional Boussinesq equation at its early stage from the saturated condition, and also suggested that storm flow recession rates vary depending on the groundwater levels. These behaviors were consistent with field observations obtained from a catchment dominated by weathered bedrock groundwater.

Sayama, Takahiro; Kosugi, Ken'ichirou

2014-05-01

357

eHEROES: where Space Weather and Communication meet  

NASA Astrophysics Data System (ADS)

Involvement of people outside the scientific community in space weather becomes more and more an issue. To raise awareness and reach involvement, we have to come up with a tide communication plan that answers the questions: what, to whom, why, when, how, by whom? One of the tools to get peoples attention and to communicate about space weather is education, both formal and informal. In the FP7 project eHEROES, a considerable effort was put in communication and dissemination through education to different sorts of audiences. We will shed some light on 'Classroom', 'Hitchhiker's guide to space' and our Quiz-database.

Vanlomel, Petra; Gressl, Corinna; Lapenta, Giovanni; Crosby, Norma B.; Cessateur, Gaël

2014-05-01

358

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

359

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

360

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

361

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.

362

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

363

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

364

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

365

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

366

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

367

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

368

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

369

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)

370

Fully Compressive Tides in Galaxy Mergers  

NASA Astrophysics Data System (ADS)

The disruptive effect of galactic tides is a textbook example of gravitational dynamics. However, depending on the shape of the potential, tides can also become fully compressive. When that is the case, they might trigger or strengthen the formation of galactic substructures (star clusters and tidal dwarf galaxies), instead of destroying them. We perform N-body simulations of interacting galaxies to quantify this effect. We demonstrate that tidal compression occurs repeatedly during a galaxy merger, independently of the specific choice of parameterization. With a model tailored to the Antennae galaxies, we show that the distribution of compressive tides matches the locations and timescales of observed substructures. After extending our study to a broad range of parameters, we conclude that neither the importance of the compressive tides (?15% of the stellar mass) nor their duration (~107 yr) is strongly affected by changes in the progenitors' configurations and orbits. Moreover, we show that individual clumps of matter can enter compressive regions several times in the course of a simulation. We speculate that this may spawn multiple star formation episodes in some star clusters, through, e.g., enhanced gas retention.

Renaud, F.; Boily, C. M.; Naab, T.; Theis, Ch.

2009-11-01

371

Semidiurnal solar tides in the mountain atmosphere  

SciTech Connect

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

Whiteman, C.D.; Bian, X.

1994-09-01

372

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.

Andrew Kane

373

Ocean energy-waves, currents, and tides  

NASA Astrophysics Data System (ADS)

An overview is presented on the mechanical forms of ocean energy; i.e., waves, currents, and tides. Following an introductory section on wave mechanics, each of the three forms of ocean energy is considered under the headings of the resource, device types for energy extraction, and prognosis for practical implementation.

Miles, J.; Shelpuk, B.

1981-05-01

374

Barotropic tides in the South Atlantic Bight  

Microsoft Academic Search

The characteristics of the principal barotropic diurnal and semidiurnal tides are examined for the South Atlantic Bight (SAB) of the eastern United States coast. We combine recent observations from pressure gauges and ADCPs on fixed platforms and additional short-term deployments off the Georgia and South Carolina coasts together with National Ocean Service coastal tidal elevation harmonics. These data have shed

Brian O. Blanton; Francisco E. Werner; Harvey E. Seim; Richard A. Luettich; Daniel R. Lynch; Keston W. Smith; George Voulgaris; Frederick M. Bingham

2004-01-01

375

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.

376

Red Tide or Neurotoxic Shellfish Poisoning  

NSDL National Science Digital Library

This web page discusses Red Tide and Neurotoxic Shellfish Poisoning, a milder gastroenteritis with neurologic symptoms compared with Paralytic Shellfish Poisoning. The classic causative organism is the dinoflagellate Gymnodinium breve, which produces neurotoxic toxins known as brevetoxins. This page describes clinical presentation of NSP (including symptoms), diagnosis, management and treatment, molecular mechanism of action, and references.

377

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

378

Red Tide Kills Fish, Fouls Gulf Coast  

NSDL National Science Digital Library

This CBS news article reports a toxic algae bloom that spread along the Texas Gulf coast in 2000, killing millions of fish and fouling beaches with their remains. The article explains how red tide affects fish and describes health threats to humans.

CBS News

379

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

380

The Equilibrium Tide Model for Tidal Friction  

Microsoft Academic Search

We derive from first principles the equations governing (a) the quadrupole tensor of a star distorted both by rotation and by the presence of a companion in a possibly eccentric orbit; (b) a functional form for the dissipative force of tidal friction, based on the concept that the rate of energy loss from a time-dependent tide should be a positive-definite

Peter P. Eggleton; Ludmila G. Kiseleva; Piet Hut

1998-01-01

381

Small geophysical signals detected in differences of altimetric tides and bottom-pressure tides  

NASA Astrophysics Data System (ADS)

Very precise tidal estimates derived from seafloor pressure measurements and from two decades of satellite altimetry are capable of revealing tiny, subtle signals in their differences. In particular, these differences can place constraints on models of atmospheric tides and solid tides. Such signals arise because altimetry is sensitive to the solid tide while bottom pressure (BP) is not, while BP is sensitive to the air tide while altimetry is not (not directly anyway). I have constructed a database of precise BP tide estimates from 151 deep-ocean stations, most based on multiple years of hourly data. The relationship between bottom pressure and equivalent sea-surface elevation must be carefully handled, since it depends on ocean stratification and the compressibility of seawater. The altimeter-BP rms differences are 5 mm or better. In these differences, the air tide is easily detected at the S1 and S2 periods and more marginally detected at the T2 and K1 periods (the latter represent seasonal sidelines of either S1 or S2); a comparison of various air-tide models favors one derived from recent 3-hourly ECMWF operational analyses. Results also show that altimetry can benefit from correcting for crustal loading by the S2 air tide; the signal is only 1.4 mm or less and has previously been ignored, but it is detectable in the altimeter-BP differences. Similarly altimetry must be corrected for the presence of the air tide in the dry troposphere correction. Finally differences also allow Love numbers to be estimated at the M2, O1, and K1 periods, with the latter clearly showing suppression from the free core-nutation resonance. However, recent estimates just published by Krasna and colleagues, using VLBI data, are far more accurate, in part because VLBI need not contend with large, possibly inconsistent ocean signals in their data. Our results could be improved once baroclininc tides are properly accounted for, but these tides, with wavelengths of order 100 km, are currently insufficiently known and may require wide-swath altimetry before they are accurately mapped.

Ray, R. D.

2013-12-01

382

The Role of Tides in Planetary Habitability  

NASA Astrophysics Data System (ADS)

Terrestrial planets in the classic "habitable zone" (Kasting et al. 1993) of stars may be influenced by tides. Tidal evolution is poorly constrained and multiple acceptable models exist which, although qualitatively similar, predict different rates of evolution. Using different models, we examine how tides may modify several key properties of planets in the habitable zone: semi-major axis, eccentricity, obliquity and rotation rate. Tides can lock the rotation rate and erode the obliquity (to 0 or 180 degrees) in 103-1010 years, depending on the stellar mass and eccentricity. Some tidal models even predict significant obliquity evolution for planets in the habitable zones of solar-mass stars. This evolution dissipates energy in the planet's interior (at the expense of the orbit) and leads to "tidal heating." In extreme cases of high eccentricity and very low mass stars, the heating may initiate a runaway greenhouse, and/or total evaporation of potential surface water, eliminating any hope of habitability. After the spin properties have equilibrated, the planet is said to be "tidally locked" and further evolution primarily changes the orbital angular momentum. For exoplanets, tides tend to reduce eccentricities and semi-major axes, and can also change the rotation period, eventually reaching synchroneity with the orbit when both eccentricity and obliquity reach zero. Orbital circularization requires millions to trillions of years, depending on the planet's initial conditions and the tidal model assumed. Tidal heating also occurs during circularization and planets may pass through a "super-Io" phase prior to reaching internal heating rates similar to the modern day Earth. Tides clearly have the potential to impact habitability and may lead to planets with evolutionary paths markedly different from the Earth. These issues are presented and discussed for the simple case of one planet orbiting one star.

Barnes, Rory; Heller, R.; Jackson, B.; Leconte, J.; Greenberg, R.; Mullins, K.; Raymond, S. N.

2011-01-01

383

Satellite-based red tide monitoring in the Korean coastal waters  

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

384

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

NASA Astrophysics Data System (ADS)

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

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

2010-05-01

385

The Association of Weather Variability and Under Five Malaria Mortality in KEMRI/CDC HDSS in Western Kenya 2003 to 2008: A Time Series Analysis  

PubMed Central

Malaria is among the leading causes of mortality in the younger under-five group of children zero to four years of age. This study aims at describing the relationship between rainfall and temperature on under-five malaria or anaemia mortality in Kenya Medical Research Institute and United States Centers for Disease Control (KEMRI/CDC) Health and Demographic Surveillance System (HDSS). This study was conducted through the ongoing KEMRI and CDC collaboration. A general additive model with a Poisson link function was fit to model the weekly association of lagged cumulative rainfall and average temperature on malaria/anemia mortality in KEMRI/CDC HDSS for the period 2003 to 2008. A trend function was included in the model to control for time trends and seasonality not explained by weather fluctuations. 95% confidence intervals was presented with estimates. Malaria or anemia mortality was found to be associated with changes in temperature and rainfall in the KEMRI HDSS, with a delay up to 16 weeks. The empirical estimates of associations describe established biological relationships well. This information, and particularly, the strength of the relationships over longer lead times can highlight the possibility of developing a predictive forecast with lead times up to 16 weeks in order to enhance preparedness to high transmission episodes. PMID:25674784

Sewe, Maquins; Rocklöv, Joacim; Williamson, John; Hamel, Mary; Nyaguara, Amek; Odhiambo, Frank; Laserson, Kayla

2015-01-01

386

The association of weather variability and under five malaria mortality in KEMRI/CDC HDSS in Western Kenya 2003 to 2008: a time series analysis.  

PubMed

Malaria is among the leading causes of mortality in the younger under-five group of children zero to four years of age. This study aims at describing the relationship between rainfall and temperature on under-five malaria or anaemia mortality in Kenya Medical Research Institute and United States Centers for Disease Control (KEMRI/CDC) Health and Demographic Surveillance System (HDSS). This study was conducted through the ongoing KEMRI and CDC collaboration. A general additive model with a Poisson link function was fit to model the weekly association of lagged cumulative rainfall and average temperature on malaria/anemia mortality in KEMRI/CDC HDSS for the period 2003 to 2008. A trend function was included in the model to control for time trends and seasonality not explained by weather fluctuations. 95% confidence intervals was presented with estimates. Malaria or anemia mortality was found to be associated with changes in temperature and rainfall in the KEMRI HDSS, with a delay up to 16 weeks. The empirical estimates of associations describe established biological relationships well. This information, and particularly, the strength of the relationships over longer lead times can highlight the possibility of developing a predictive forecast with lead times up to 16 weeks in order to enhance preparedness to high transmission episodes. PMID:25674784

Sewe, Maquins; Rocklöv, Joacim; Williamson, John; Hamel, Mary; Nyaguara, Amek; Odhiambo, Frank; Laserson, Kayla

2015-02-01

387

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

388

Weather in Your Life.  

ERIC Educational Resources Information Center

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

Kannegieter, Sandy; Wirkler, Linda

389

U.P. Weather Burcw, Psalininary report on H w r i cane "DIILTPB",  

E-print Network

The hurricane caused sharery weather Over eastern South Carolina on August 16th and 17th. -.were 1t o 2 feet center. No hurricane winds were reported i n South Carolina, though tides Damage tn South Carolina has entered the North Carolina coast on the morning of August 17th near Wilmington, North Cwolina. After

390

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

E-print Network

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

Nimmo, Francis

391

Weather Modification A Theoretician's Viewpoint.  

NASA Astrophysics Data System (ADS)

Early progress in weather modification is attributed to a healthy interaction between theory and experiment. During the 1970s, a divergence of approaches took place. A "theoretical/experimental" approach, exemplified by the Cascade Project, focused on testing scientific hypotheses; an "observational/experimental" approach, exemplified by the Colorado River Basin Pilot Project, sought to enhance understanding of the seeding process through more detailed observations.The theoretical/experimental school soon came to focus almost exclusively on natural cloud processes, leaving the field of weather modification nearly devoid of a theoretical component. It is suggested that this theoretical component is necessary to revitalize the field of weather modification.Key questions are addressed. These include 1) identification of clouds that are amenable to seeding; 2) glaciogenic versus hygroscopic seeding; 3) optimizing critical seeding variables, such as seed particle concentration for glaciogenic seeding and seed particle size for hygroscopic seeding; and 4) seeding for hail suppression.

Young, Kenneth C.

1996-11-01

392

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

393

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

NASA Technical Reports Server (NTRS)

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

Hung, Ching-Cheh

2007-01-01

394

What's the Weather?  

NSDL National Science Digital Library

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

2005-01-01

395

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.

396

Monitoring storm tide and flooding from Hurricane Isaac along the Gulf Coast of the United States, August 2012  

USGS Publications Warehouse

The U.S. Geological Survey (USGS) deployed a temporary monitoring network of water-level and barometric pressure sensors at 127 locations along the gulf coast from Alabama to Louisiana to record the timing, areal extent, and magnitude of hurricane storm tide and coastal flooding generated by Hurricane Isaac. This deployment was undertaken as part of a coordinated federal emergency response as outlined by the Stafford Act under a directed mission assignment by the Federal Emergency Management Agency. Storm tide, as defined by National Oceanic and Atmospheric Administration (NOAA; National Oceanic and Atmospheric Administration, 2008), is the water-level rise generated by a combination of storm surge and astronomical tide during a coastal storm. Hurricane Isaac initially made landfall on the coast of Louisiana in Plaquemines Parish on August 28, 2012, as a Category 1 hurricane on the Saffir–Simpson Hurricane Wind Scale (National Weather Service, 1974) and then stalled over southern Louisiana for several days, causing prolonged storm-tide impacts. A total of 188 water-level and wave-height sensors were deployed at 127 locations during August 27–28 prior to landfall. More than 90 percent of the sensors and all high-water marks (HWMs) were recovered and surveyed to North American Vertical Datum of 1988 (NAVD 88) within 7 days of the Isaac landfall. Only a handful of sensors in the Plaquemines Parish area of Louisiana could not be retrieved until weeks later due to prolonged flooding in the area. Data collected from this event can be used to evaluate the performance of storm-tide models for maximum and incremental water level and flood extent and the site-specific effects of storm tide on natural and anthropogenic features of the environment.

McCallum, Brian E.; McGee, Benton D.; Kimbrow, Dustin R.; Runner, Michael S.; Painter, Jaime A.; Frantz, Eric R.; Gotvald, Anthony J.

2012-01-01

397

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

398

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

399

Semidiurnal Internal Tides in Massachusetts Bay  

Microsoft Academic Search

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

David Halpern

1971-01-01

400

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.

Woods Hole Oceanographic Institution

401

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

402

Weather and climate applications for rangeland restoration planning  

Technology Transfer Automated Retrieval System (TEKTRAN)

Rangeland ecosystems generally have an arid or semi-arid climatology, and are characterized by relatively high variability in seasonal and annual patterns of precipitation. Weather variability during seedling establishment is universally acknowledged as a principal determinant of rangeland seeding...

403

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

404

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

405

Weather Information System  

NASA Technical Reports Server (NTRS)

WxLink is an aviation weather system based on advanced airborne sensors, precise positioning available from the satellite-based Global Positioning System, cockpit graphics and a low-cost datalink. It is a two-way system that uplinks weather information to the aircraft and downlinks automatic pilot reports of weather conditions aloft. Manufactured by ARNAV Systems, Inc., the original technology came from Langley Research Center's cockpit weather information system, CWIN (Cockpit Weather INformation). The system creates radar maps of storms, lightning and reports of surface observations, offering improved safety, better weather monitoring and substantial fuel savings.

1995-01-01

406

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

407

Space Weather FX  

NSDL National Science Digital Library

Space Weather FX is a vodcast (video podcast) series that explores the science of space weather and how it can impact our every day lives. Episodes include Space Weather and its Effects, Connecting the Sun and Earth, When Space Weather Attacks, Stratospheric Sudden Warming, A Tour of Haystack's Radars, GPS and Space Weather, It Came from the Sun, and The Big Picture. The site also contain links to space weather information and educational materials. The episodes will run on one of four free video players.

408

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? ...

Mrs. Emma Grasser

2012-09-27

409

Edheads: Weather Activities  

NSDL National Science Digital Library

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

2010-01-01

410

Science Sampler: Weather RATS  

NSDL National Science Digital Library

Weather RATS, or Weather Research and Tracking Systems, is a collaborative effort among a national network of K-12 students, their teachers, wireless weather stations, internet data sharing, and professional engineers and meteorologists. Weather Rats is a new way to teach K-12 science and technology by tracking and comparing weather data from schools in Massachusetts, Arizona, Oklahoma, and Puerto Rico. In addition, it is hoped through this enriching project that Weather RATS will inspire many more students, especially girls and minorities, to pursue careers in science and engineering as a result of this project.

Mary Taft

2006-02-01

411

Climate Change and Extreme Weather  

NSDL National Science Digital Library

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

2014-09-14

412

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

413

Nonmigrating semidiurnal and diurnal tides at 95 km based on wind measurements from the High Resolution Doppler Imager on UARS  

Microsoft Academic Search

For more than a decade, derived results from the High Resolution Doppler Imager (HRDI) on UARS have provided an enormous amount of new and invaluable information on the global variability of atmospheric winds. These and other results have given added impetus to theoretical modeling efforts. Until recent years, the large majority of investigations have focused on migrating tides, and now

Frank T. Huang; Carl A. Reber

2004-01-01

414

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

415

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

NASA Astrophysics Data System (ADS)

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

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

2010-05-01

416

Winter Weather: Frostbite  

MedlinePLUS

... Matters What's New A - Z Index Disasters & Severe Weather Earthquakes Extreme Heat Floods Hurricanes Landslides Tornadoes Tsunamis ... related health problems. More Information: Hypothermia Disasters & Severe Weather Earthquakes Extreme Heat Floods Hurricanes Landslides Tornadoes Tsunamis ...

417

Winter Weather Emergencies  

MedlinePLUS

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

418

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

Mark Francek

2002-10-01

419

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

420

On Observing the Weather  

NSDL National Science Digital Library

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

Peter Crane

2004-05-01

421

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 &quot;first alert system&quot; now in place now monitors for sunlight and nutrient concentrations that may lead to red tide events.

Misty Edgecomb

422

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

423

Internal tides and turbulent mixing observed in the Bussol Strait  

NASA Astrophysics Data System (ADS)

Repeated observations with a period of about 24 h of hydrography, current velocity, and microstructures were performed at three stations surrounding a seamount in the middle of the Bussol Strait, the deepest and widest one of the Kuril Straits, to reveal spatial and temporal variability of internal tides and associated turbulent mixing. It is found that isopycnal displacements are dominated by diurnal tidal components, which show phase differences (namely, time lags) between the three stations that can be explained by a first mode topographically trapped wave (TTW) propagating clockwise around the seamount. Furthermore, at the station located near the center of the strait where energy dissipation rates are largest, diurnal variations of isopycnals and velocities are amplified toward the ocean bottom, consistent with the vertical structure of the first mode TTW. At that station, vigorous turbulent mixing with the energy dissipation rate exceeding 10-6 m2 s-3 and diapycnal diffusivity exceeding 10-1 m2 s-1 was observed in deep layers when the diurnal tidal current consisting of the first mode TTW flows from the Okhotsk Sea to the North Pacific, enhancing the mean current. These spatial and temporal variation patterns are confirmed to be reproduced by a previous numerical model successfully for the isopycnals and velocities, and partially for the turbulent mixing. The total energy dissipation rate is, however, by up to a factor of 3-10 smaller than predicted by the numerical model although the observations were performed during spring tides, suggesting that the actual diapycnal mixing is overall weaker than the previous model estimate and/or that extremely strong mixing occurs within highly localized areas.

Tanaka, Yuki; Yasuda, Ichiro; Osafune, Satoshi; Tanaka, Takahiro; Nishioka, Jun; Volkov, Yuri N.

2014-08-01

424

Numerical study of solute transport in shallow beach aquifers subjected to waves and tides  

NASA Astrophysics Data System (ADS)

A numerical study was conducted to investigate the fate of solute in a laboratory beach in response to waves and tides. A new temporal upscaling approach labeled "net inflow" was introduced to address impacts of waves on solute transport within beaches. Numerical simulations using a computational fluid dynamic model were used as boundary conditions for the two-dimensional variably saturated flow and solute transport model MARUN. The modeling approach was validated against experimental data of solute transport due to waves and tides. Exchange fluxes across the beach face and subsurface solute transport (e.g., trajectory, movement speed, and residence time) were quantified. Simulation results revealed that waves increased the exchange fluxes, and engendered a wider exchange flux zone along the beach surface. Compared to tide-only forcing, waves superimposed on tide caused the plume to be deeper into the beach, and to migrate more seaward. The infiltration into the beach was found to be directly proportional to the general hydraulic gradient in the beach and inversely proportional to the matrix retention (or capillary) capacity. The simulations showed that a higher inland water table would attenuate wave-caused seawater infiltration, which might impact beach geochemical processes (e.g., nutrient recycle and redox condition), especially at low tide zone. The concept of biochemical residence time maps (BRTM) was introduced to account for the net effect of limiting concentration of chemicals on biochemical reactions. It was found that waves shifted the BRTMs downward and seaward in the beach, and subsequently they engendered different biochemical conditions within the beach.

Geng, Xiaolong; Boufadel, Michel C.

2015-02-01

425

Fire Weather Climatology  

NSDL National Science Digital Library

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

COMET

2008-04-28

426

Enviropedia: Introduction to Weather  

NSDL National Science Digital Library

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

2007-12-12

427

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.

2014-09-14

428

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

429

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

430

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

431

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.

432

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

433

Extreme Weather on Earth  

NSDL National Science Digital Library

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

Anna Mika

434

METEOROLOGICAL Weather and Forecasting  

E-print Network

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

435

Predicting Seasonal Weather  

NSDL National Science Digital Library

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

Cheryl Dybas

2008-12-07

436

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

437

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

438

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 ...

439

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

440

Weather Girl Goes Rogue  

NSDL National Science Digital Library

This humorous video suggests what might happen if a weather forecaster reported the weather in the context of climate change. There is a sharp contrast between the anchor focusing on short-term local concerns and the weather forecaster describing what is happening on a long-term global basis.

Deep Rogue Ram

441

American Weather Stories.  

ERIC Educational Resources Information Center

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

Hughes, Patrick

442

Space Weather Now  

NSDL National Science Digital Library

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

Space Environment Center

443

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.

National Geographic

444

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

445

Convective Weather Avoidance with Uncertain Weather Forecasts  

NASA Technical Reports Server (NTRS)

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

Karahan, Sinan; Windhorst, Robert D.

2009-01-01

446

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

447

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.

448

The Tides Of Time Issue 35  

E-print Network

The Tides of Time Issue 35 Michaelmas Term 2011 Editor Adam Povey adam.povey@sjc.ox.ac.uk Contents: Silence in the Library 3 The society's resident video game reviewer considers Shadows of the Vashta Nerada and Evacuation Earth. “You can believe... this subject is a part of the Doctor Who universe. But we don’t.” 8 Sara James explores the possibility that Journey's End gave fandom a way to canonise the Peter Cushing films. Season Seventeen – Douglas Adams and Doctor Who's Lost Renaissance of 1979 12...

2001-01-01

449

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

450

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

451

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

452

WeatherHawk Weather Station Protocol  

NSDL National Science Digital Library

This resource provides instructions on how to log atmosphere data using a WeatherHawk weather station. A weather station is setup to measure and record atmospheric measurements at 15-minute intervals and can be transferred to the GLOBE program via email. Students can view data for their school that are continuous and show variations within a day. The data collected includes wind speed and direction and pressure thereby supporting a more complete study of meteorology using GLOBE. Students pursue a more extensive set of research investigations.

The GLOBE Program, UCAR (University Corporation for Atmospheric Research)

2003-08-01

453

Fabulous Weather Day  

NSDL National Science Digital Library

Each year, first graders at Kensington Parkwood Elementary School in Kensington, Maryland, look forward to Fabulous Weather Day. After studying weather for three months, we celebrate what we have learned and stretch our thinking further into the weather world around us! Students learn how meteorologists collect data about the weather, how they study wind, temperature, precipitation, basic types/characteristics of clouds, and how they forecast. The project helps the students grow in their understanding of how the weather works and how it can affect their lives. Our unit focused on guiding students to formulate explanations about animals based on scientific evidence.

Candice Marshall

2007-01-01

454

Modelling the effects of tides and storm surges on coastal aquifers using a coupled surface-subsurface approach.  

PubMed

Coastal aquifers are complex hydrologic systems because many physical processes interact: (i) variably saturated flow, (ii) spatial-temporal fluid density variations, (iii) tidal fluctuations, (iv) storm surges overtopping dykes, and (v) surface runoff of storm water. The HydroGeoSphere model is used to numerically simulate coastal flow dynamics, assuming a fully coupled surface-subsurface approach, accounting for all processes listed above. The diffusive wave approximation of the St. Venant equation is used to describe surface flow. Surface flow and salt transport are fully coupled with subsurficial variably saturated, variable-density flow and salt transport through mathematical terms that represent exchange of fluid mass and solute mass, respectively. Tides and storm surges induce a time-variant head that is applied to nodes of the surface domain. The approach is applied to real cases of tide and storm surge events. Tide simulation results confirm the existence of a recirculating zone, forming beneath the upper part of the intertidal zone. By monitoring the exchange fluid flux rates through the beach, it was found that the major inflow to the aquifer takes place at the upper part of the intertidal zone, which explains the formation of the recirculating zone. The recirculating zone is forming particularly during rising tide. Results from a storm surge simulation show that plume fingers develop below the flooded land surface. Natural remediation by seaward flowing freshwater is relatively slow, such that reducing the salt concentration in the aquifer down to drinking water standards takes up to 10 years. PMID:23603354

Yang, Jie; Graf, Thomas; Herold, Maria; Ptak, Thomas

2013-06-01

455

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

456

Atmospheric tides in the low-latitude E and F regions and their responses to a sudden stratospheric warming event in January 2010  

NASA Astrophysics Data System (ADS)

extensive analysis of atmospheric tides in the low-latitude thermosphere and their responses to a major sudden stratospheric warming (SSW) event (18-23 January 2010) is presented. The analysis is based on observational data from the Arecibo dual-beam incoherent scatter radar. Important findings of the present study are as follows. (1) The diurnal tide with an evanescent phase structure dominates the F region meridional wind field. The diurnal tide has a peak amplitude of 45 m/s occurring at about 245 km, and it is very stable throughout the nine consecutive days' observation. Below 114 km, the vertical structures of the diurnal tide in the meridional and zonal components are consistent, which resemble the classical solar S1, 1 tidal mode. (2) The F region semidiurnal tide is much weaker and has larger day-to-day variability than the diurnal tide. In the E region, the semidiurnal amplitudes in the meridional and zonal components grow continuously in the altitude ranges from 106 to 121 km and from 100 to 115 km, respectively. The vertical wavelength of the zonal component is estimated to be 45 km above 100 km, which is close to the solar S2, 4 and S2, 5 tidal modes. (3) The semidiurnal and terdiurnal tides respond strongly to the SSW while the impact that the SSW has on the diurnal tide in the meridional wind is limited. During the SSW event, the amplitudes of the semidiurnal and terdiurnal tides are enhanced in the F region but reduced in the upper E region.

Gong, Yun; Zhou, Qihou; Zhang, Shaodong

2013-12-01

457

Is there a hot spot of sea level rise acceleration along the mid-Atlantic United States? A Gaussian process decomposition of tide gauge records  

E-print Network

Recent research has suggested faster-than-global acceleration of sea level rise along the northeastern coast of the United States. To test this claim, I construct a Gaussian process model of tide gauge records, decomposing the tide gauge data into a smooth, long-term trend and red noise-type short-term variability (due to short-term ocean dynamics). This approach accommodates data gaps and allows decomposition of signals into local, regional, and global components. While tide gauge records do indicate a current faster-than-global increase in the rate of sea level rise in the mid-Atlantic region, this regional acceleration could reflect either the start of a long-term trend or short-term ocean dynamics. Current tide gauge data are insufficient to discriminate between these alternatives, and they will continue to be so for about two decades.

Kopp, Robert E

2013-01-01

458

Avalanche Weather Forecasting  

NSDL National Science Digital Library

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

COMET

2010-09-30

459

Plymouth State Weather Center  

NSDL National Science Digital Library

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

460

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

461

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

462

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.

463

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

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

464

Weather: What Forces Affect Our Weather?  

NSDL National Science Digital Library

This website provides an easy-to-understand look at our weather system. Topics covered include the atmosphere, the water cycle, storms, ice and snow, weather forecasting and Earth's changing climate. There are features on ozone depletion, global warming, El Nino and La Nina. An activity allows users to identify cloud formations associated with tornadoes, complete with photographs. There is also a wind chill calculator.

2002-06-11

465

Panic anxiety, under the weather?  

NASA Astrophysics Data System (ADS)

The relationship between weather conditions and psychiatric disorders has been a continuous subject of speculation due to contradictory findings. This study attempts to further clarify this relationship by focussing on specific conditions such as panic attacks and non-panic anxiety in relation to specific meteorological variables. All psychiatric emergencies attended at a general hospital in Barcelona (Spain) during 2002 with anxiety as main complaint were classified as panic or non-panic anxiety according to strict independent and retrospective criteria. Both groups were assessed and compared with meteorological data (wind speed and direction, daily rainfall, temperature, humidity and solar radiation). Seasons and weekend days were also included as independent variables. Non-parametric statistics were used throughout since most variables do not follow a normal distribution. Logistic regression models were applied to predict days with and without the clinical condition. Episodes of panic were three times more common with the poniente wind (hot wind), twice less often with rainfall, and one and a half times more common in autumn than in other seasons. These three trends (hot wind, rainfall and autumn) were accumulative for panic episodes in a logistic regression formula. Significant reduction of episodes on weekends was found only for non-panic episodes. Panic attacks, unlike other anxiety episodes, in a psychiatric emergency department in Barcelona seem to show significant meteorotropism. Assessing specific disorders instead of overall emergencies or other variables of a more general quality could shed new light on the relationship between weather conditions and behaviour.

Bulbena, A.; Pailhez, G.; Aceña, R.; Cunillera, J.; Rius, A.; Garcia-Ribera, C.; Gutiérrez, J.; Rojo, C.

2005-03-01

466

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...

467

Energetics of global ocean tides from Geosat altimetry  

NASA Technical Reports Server (NTRS)

The present paper focuses on resonance and energetics of the daily tides, especially in the southern ocean, the distribution of gravitational power input of daily and half-daily tides, and comparison with other estimates of global dissipation rates. The present global tidal maps, derived from Geosat altimetry, compare favorably with ground truth data at about the same rms level as the models of Schwiderski (1983), and are slightly better in lunar than in solar tides. Diurnal admittances clearly show Kelvin wave structure in the southern ocean and confirm the resonant mode of Platzman (1984) at 28.5 + or - 0.1 hr with an apparent Q of about 4. Driving energy is found to enter dominantly in the North Pacific for the daily tides and is strongly peaked in the tropical oceans for the half-daily tides. Global rates of working on all major tide constituents except S2 agree well with independent results from analyses of gravity through satellite tracking. Comparison at S2 is improved by allowing for the air tide in gravitational results but suggests deficiencies in all solar tide models.

Cartwright, David E.; Ray, Richard D.

1991-01-01

468

Atmospheric tides and the rotation of Venus. II - Spin evolution  

NASA Technical Reports Server (NTRS)

Tides in the atmosphere of Venus may help to stabilize its slow retrograde rotation. The frequency dependence of the body tides also affects its rotational stability. However, the obliquity is probably maintained near 180 deg by friction between the core and mantle of Venus. In any case, it appears most likely that Venus originated with an obliquity greater than 90 deg.

Dobrovolskis, A. R.

1980-01-01

469

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