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Sample records for aerosolized red tide

  1. Characterization of Florida red tide aerosol and the temporal profile of aerosol concentration

    PubMed Central

    Cheng, Yung Sung; Zhou, Yue; Pierce, Richard H.; Henry, Mike; Baden, Daniel G.

    2009-01-01

    Red tide aerosols containing aerosolized brevetoxins are produced during the red tide bloom and transported by wind to coastal areas of Florida. This study reports the characterization of Florida red tide aerosols in human volunteer studies, in which an asthma cohort spent 1 h on Siesta Beach (Sarasota, Florida) during aerosolized red tide events and non-exposure periods. Aerosol concentrations, brevetoxin levels, and particle size distribution were measured. Hourly filter samples were taken and analyzed for brevetoxin and NaCl concentrations. In addition, the aerosol mass concentration was monitored in real time. The results indicated that during a non-exposure period in October 2004, no brevetoxin was detected in the water, resulting in non-detectable levels of brevetoxin in the aerosol. In March 2005, the time-averaged concentrations of brevetoxins in water samples were moderate, in the range of 5–10 μg/L, and the corresponding brevetoxin level of Florida red tide aerosol ranged between 21 and 39 ng/m3. The temporal profiles of red tide aerosol concentration in terms of mass, NaCl, and brevetoxin were in good agreement, indicating that NaCl and brevetoxins are components of the red tide aerosol. By continuously monitoring the marine aerosol and wind direction at Siesta Beach, we observed that the marine aerosol concentration varied as the wind direction changed. The temporal profile of the Florida red tide aerosol during a sampling period could be explained generally with the variation of wind direction. PMID:19879288

  2. Characterization of Florida red tide aerosol and the temporal profile of aerosol concentration.

    PubMed

    Cheng, Yung Sung; Zhou, Yue; Pierce, Richard H; Henry, Mike; Baden, Daniel G

    2010-05-01

    Red tide aerosols containing aerosolized brevetoxins are produced during the red tide bloom and transported by wind to coastal areas of Florida. This study reports the characterization of Florida red tide aerosols in human volunteer studies, in which an asthma cohort spent 1h on Siesta Beach (Sarasota, Florida) during aerosolized red tide events and non-exposure periods. Aerosol concentrations, brevetoxin levels, and particle size distribution were measured. Hourly filter samples were taken and analyzed for brevetoxin and NaCl concentrations. In addition, the aerosol mass concentration was monitored in real time. The results indicated that during a non-exposure period in October 2004, no brevetoxin was detected in the water, resulting in non-detectable levels of brevetoxin in the aerosol. In March 2005, the time-averaged concentrations of brevetoxins in water samples were moderate, in the range of 5-10 microg/L, and the corresponding brevetoxin level of Florida red tide aerosol ranged between 21 and 39 ng/m(3). The temporal profiles of red tide aerosol concentration in terms of mass, NaCl, and brevetoxin were in good agreement, indicating that NaCl and brevetoxins are components of the red tide aerosol. By continuously monitoring the marine aerosol and wind direction at Siesta Beach, we observed that the marine aerosol concentration varied as the wind direction changed. The temporal profile of the Florida red tide aerosol during a sampling period could be explained generally with the variation of wind direction.

  3. Overview of Aerosolized Florida Red Tide Toxins: Exposures and Effects

    PubMed Central

    Fleming, Lora E.; Backer, Lorraine C.; Baden, Daniel G.

    2005-01-01

    Florida red tide is caused by Karenia brevis, a dinoflagellate that periodically blooms, releasing its potent neurotoxin, brevetoxin, into the surrounding waters and air along the coast of the Gulf of Mexico. Exposure to Florida red tide toxins has been associated with adverse human health effects and massive fish and marine mammal deaths. The articles in this mini-monograph describe the ongoing interdisciplinary and interagency research program that characterizes the exposures and health effects of aerosolized Florida red tide toxins (brevetoxins). The interdisciplinary research program uses animal models and laboratory studies to develop hypotheses and apply these findings to in situ human exposures. Our ultimate goal is to develop appropriate prevention measures and medical interventions to mitigate or prevent adverse health effects from exposure to complex mixtures of aerosolized red tide toxins. PMID:15866773

  4. Aerosolized Red-Tide Toxins (Brevetoxins) and Asthma

    PubMed Central

    Fleming, Lora E.; Kirkpatrick, Barbara; Backer, Lorraine C.; Bean, Judy A.; Wanner, Adam; Reich, Andrew; Zaias, Julia; Cheng, Yung Sung; Pierce, Richard; Naar, Jerome; Abraham, William M.; Baden, Daniel G.

    2009-01-01

    Background With the increasing incidence of asthma, there is increasing concern over environmental exposures that may trigger asthma exacerbations. Blooms of the marine microalgae, Karenia brevis, cause red tides (or harmful algal blooms) annually throughout the Gulf of Mexico. K brevis produces highly potent natural polyether toxins, called brevetoxins, which are sodium channel blockers, and possibly histamine activators. In experimental animals, brevetoxins cause significant bronchoconstriction. In humans, a significant increase in self-reported respiratory symptoms has been described after recreational and occupational exposures to Florida red-tide aerosols, particularly among individuals with asthma. Methods Before and after 1 h spent on beaches with and without an active K brevis red-tide exposure, 97 persons ≥ 12 years of age with physician-diagnosed asthma were evaluated by questionnaire and spirometry. Concomitant environmental monitoring, water and air sampling, and personal monitoring for brevetoxins were performed. Results Participants were significantly more likely to report respiratory symptoms after K brevis red-tide aerosol exposure than before exposure. Participants demonstrated small, but statistically significant, decreases in FEV1, midexpiratory phase of forced expiratory flow, and peak expiratory flow after exposure, particularly among those participants regularly using asthma medications. No significant differences were detected when there was no Florida red tide (ie, during nonexposure periods). Conclusions This study demonstrated objectively measurable adverse changes in lung function from exposure to aerosolized Florida red-tide toxins in asthmatic subjects, particularly among those requiring regular therapy with asthma medications. Future studies will assess these susceptible subpopulations in more depth, as well as the possible long-term effects of these toxins. PMID:17218574

  5. Personal exposure to aerosolized red tide toxins (brevetoxins).

    PubMed

    Cheng, Yung Sung; Zhou, Yue; Naar, Jerome; Irvin, C Mitch; Su, Wei-Chung; Fleming, Lora E; Kirkpatrick, Barbara; Pierce, Richard H; Backer, Lorraine C; Baden, Daniel G

    2010-06-01

    Florida red tides occur annually in the Gulf of Mexico from blooms of the marine dinoflagellate, Karenia brevis, which produces highly potent natural polyether toxins, brevetoxins. Several epidemiologic studies have demonstrated that human exposure to red tide aerosol could result in increased respiratory symptoms. Environmental monitoring of aerosolized brevetoxins was performed using a high-volume sampler taken hourly at fixed locations on Siesta Beach, Florida. Personal exposure was monitored using personal air samplers and taking nasal swab samples from the subjects who were instructed to spend 1 hr on Sarasota Beach during two sampling periods of an active Florida red tide event in March 2005, and in May 2008 when there was no red tide. Results showed that the aerosolized brevetoxins from the personal sampler were in modest agreement with the environmental concentration taken from a high-volume sampler. Analysis of nasal swab samples for brevetoxins demonstrated 68% positive samples in the March 2005 sampling period when air concentrations of brevetoxins were between 50 to 120 ng/m(3) measured with the high-volume sampler. No swab samples showed detectable levels of brevetoxins in the May 2008 study, when all personal samples were below the limit of detection. However, there were no statistical correlations between the amounts of brevetoxins detected in the swab samples with either the environmental or personal concentration. Results showed that the personal sample might provide an estimate of individual exposure level. Nasal swab samples showed that brevetoxins indeed were inhaled and deposited in the nasal passage during the March 2005 red tide event.

  6. An Epidemiologic Approach to the Study of Aerosolized Florida Red Tides.

    PubMed

    Fleming, Lora E; Backer, Lorraine C; Kirkpatrick, Barbara; Clark, Richard; Dalpra, Dana; Johnson, David R; Bean, Judy A; Cheng, Yung Sung; Benson, Janet; Squicciarrini, Dominick; Abraham, William M; Pierce, Richard; Zaias, Julia; Naar, Jerome; Weisman, Richard; Bossart, Greg; Campbell, Susan; Wanner, Adam; Harrington, Mark; Van De Bogart, Gayl; Baden, Daniel G

    Very little has been published in the scientific literature on the human health effects of Florida red tide, either as human clinical case reports or formal epidemiologic studies. In addition to the health effects associated with the ingestion of contaminated shellfish, there have been multiple anecdotal reports of respiratory irritation and possible immunologic effects associated with the inhalation of aerosolized Florida red tide. To investigate the human health effects from environmental exposure to red tide toxins, we have formed an interdisciplinary team of scientists. We have created a network of public and environmental health workers who periodically report local conditions as a red tide develops. In addition, we have access to environmental monitoring data as well as data from a surveillance program supported through the Florida Poison Information Network. When a red tide moves onshore where people might be exposed, the team rapidly assembles at the site to collect environmental samples and epidemiologic data. To assess the more long-term effects from environmental exposure to red tide toxins, we are conducting epidemiologic studies involving occupational and sensitive populations who live in areas that are regularly impacted by red tides. Other scientists are evaluating the acute and chronic respiratory effects of red tides and brevetoxins in both rat and sheep models as well as refinement of toxin measurement methodology. These models are being used to refine and validate the biomarkers of brevetoxins exposure as well as explore the pathophysiology of health effects from brevetoxins respiratory exposure. Bolstered by the additional research in rat and sheep models, this interdisciplinary scientific team is exploring the acute and chronic exposures and health effects of aerosolized Florida red tides in animal models and various human populations. In the future, this research can be applied to the understanding of exposure and effects of other aerosolized

  7. Occupational Exposure to Aerosolized Brevetoxins during Florida Red Tide Events: Effects on a Healthy Worker Population

    PubMed Central

    Backer, Lorraine C.; Kirkpatrick, Barbara; Fleming, Lora E.; Cheng, Yung Sung; Pierce, Richard; Bean, Judy A.; Clark, Richard; Johnson, David; Wanner, Adam; Tamer, Robert; Zhou, Yue; Baden, Daniel G.

    2005-01-01

    Karenia brevis (formerly Gymnodinium breve) is a marine dinoflagellate responsible for red tides that form in the Gulf of Mexico. K. brevis produces brevetoxins, the potent toxins that cause neurotoxic shellfish poisoning. There is also limited information describing human health effects from environmental exposures to brevetoxins. Our objective was to examine the impact of inhaling aerosolized brevetoxins during red tide events on self-reported symptoms and pulmonary function. We recruited a group of 28 healthy lifeguards who are occupationally exposed to red tide toxins during their daily work-related activities. They performed spirometry tests and reported symptoms before and after their 8-hr shifts during a time when there was no red tide (unexposed period) and again when there was a red tide (exposed period). We also examined how mild exercise affected the reported symptoms and spirometry tests during unexposed and exposed periods with a subgroup of the same lifeguards. Environmental sampling (K. brevis cell concentrations in seawater and brevetoxin concentrations in seawater and air) was used to confirm unexposed/exposed status. Compared with unexposed periods, the group of lifeguards reported more upper respiratory symptoms during the exposed periods. We did not observe any impact of exposure to aerosolized brevetoxins, with or without mild exercise, on pulmonary function. PMID:15866778

  8. Initial Evaluation of the Effects of Aerosolized Florida Red Tide Toxins (Brevetoxins) in Persons with Asthma

    PubMed Central

    Fleming, Lora E.; Kirkpatrick, Barbara; Backer, Lorraine C.; Bean, Judy A.; Wanner, Adam; Dalpra, Dana; Tamer, Robert; Zaias, Julia; Cheng, Yung Sung; Pierce, Richard; Naar, Jerome; Abraham, William; Clark, Richard; Zhou, Yue; Henry, Michael S.; Johnson, David; Van De Bogart, Gayl; Bossart, Gregory D.; Harrington, Mark; Baden, Daniel G.

    2005-01-01

    Florida red tides annually occur in the Gulf of Mexico, resulting from blooms of the marine dinoflagellate Karenia brevis. K. brevis produces highly potent natural polyether toxins, known as brevetoxins, that activate voltage-sensitive sodium channels. In experimental animals, brevetoxins cause significant bronchoconstriction. A study of persons who visited the beach recreationally found a significant increase in self-reported respiratory symptoms after exposure to aerosolized Florida red tides. Anecdotal reports indicate that persons with underlying respiratory diseases may be particularly susceptible to adverse health effects from these aerosolized toxins. Fifty-nine persons with physician-diagnosed asthma were evaluated for 1 hr before and after going to the beach on days with and without Florida red tide. Study participants were evaluated with a brief symptom questionnaire, nose and throat swabs, and spirometry approved by the National Institute for Occupational Safety and Health. Environmental monitoring, water and air sampling (i.e., K. brevis, brevetoxins, and particulate size distribution), and personal monitoring (for toxins) were performed. Brevetoxin concentrations were measured by liquid chromatography mass spectrometry, high-performance liquid chromatography, and a newly developed brevetoxin enzyme-linked immunosorbent assay. Participants were significantly more likely to report respiratory symptoms after Florida red tide exposure. Participants demonstrated small but statistically significant decreases in forced expiratory volume in 1 sec, forced expiratory flow between 25 and 75%, and peak expiratory flow after exposure, particularly those regularly using asthma medications. Similar evaluation during nonexposure periods did not significantly differ. This is the first study to show objectively measurable adverse health effects from exposure to aerosolized Florida red tide toxins in persons with asthma. Future studies will examine the possible chronic

  9. Aerosol deposition favors red tide phytoplankton in the East China Sea

    NASA Astrophysics Data System (ADS)

    Mackey, K. R.; Chien, C.; Chen, Y.; Glover, D. M.; Paytan, A.

    2013-12-01

    Chinese marginal seas support vast fisheries and vital economies, but their productivity is threatened by eutrophication from runoff and atmospheric deposition. The East China Sea is inundated with nitrogen from the Yangtze River and anthropogenic emissions, leading to elevated N:P ratios. We show that aerosol additions approximating one week of moderate deposition to offshore waters favor the growth of red tide phytoplankton, such as Skeletonema costatum, by providing nutrients and trace metals (iron and zinc) needed for growth. In contrast toxin-producing Pseudonitzchia does not benefit from aerosols in this region, possibly due to its preference for lower N:P ratios. A dose-dependent toxic response was observed in Synechococcus at high aerosol loads approximating a week of heavy deposition in the region. In contrast, phytoplankton growth at an onshore station was light limited, and aerosol additions did not have an appreciable effect on phytoplankton growth. Aerosol and chlorophyll observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite have the potential to explore the effect of aerosols on phytoplankton blooms over longer time scales and seasons. This study shows the potential for aerosols to control N:P ratios in offshore waters and to shape the phytoplankton community through fertilization and toxicity, contributing to the occurrence of red tides.

  10. Aerosolized Red Tide Toxins (Brevetoxins) and Asthma: Continued health effects after 1 hour beach exposure

    PubMed Central

    Kirkpatrick, Barbara; Fleming, Lora E; Bean, Judy A; Nierenberg, Kate; Backer, Lorraine C; Cheng, Yung Sung; Pierce, Richard; Reich, Andrew; Naar, Jerome; Wanner, Adam; Abraham, William M; Zhou, Yue; Hollenbeck, Julie; Baden, Daniel G

    2010-01-01

    Blooms of the toxic dinoflagellate, Karenia brevis, produce potent neurotoxins in marine aerosols. Recent studies have demonstrated acute changes in both symptoms and pulmonary function in asthmatics after only 1 hour of beach exposure to these aerosols. This study investigated if there were latent and/or sustained effects in asthmatics in the days following the initial beach exposure during periods with and without an active Florida red tide. Symptom data and spirometry data were collected before and after 1 hour of beach exposure. Subjects kept daily symptom diaries and measured their peak flow each morning for 5 days following beach exposure. During non-exposure periods, there were no significant changes in symptoms or pulmonary function either acutely or over 5 days of follow-up. After the beach exposure during an active Florida red tide, subjects had elevated mean symptoms which did not return to the pre-exposure baseline for at least 4 days. The peak flow measurements decreased after the initial beach exposure, decreased further within 24 hours, and continued to be suppressed even after 5 days. Asthmatics may continue to have increased symptoms and delayed respiratory function suppression for several days after 1 hour of exposure to the Florida red tide toxin aerosols. PMID:21499552

  11. Aerosolized Red Tide Toxins (Brevetoxins) and Asthma: Continued health effects after 1 hour beach exposure.

    PubMed

    Kirkpatrick, Barbara; Fleming, Lora E; Bean, Judy A; Nierenberg, Kate; Backer, Lorraine C; Cheng, Yung Sung; Pierce, Richard; Reich, Andrew; Naar, Jerome; Wanner, Adam; Abraham, William M; Zhou, Yue; Hollenbeck, Julie; Baden, Daniel G

    2011-01-01

    Blooms of the toxic dinoflagellate, Karenia brevis, produce potent neurotoxins in marine aerosols. Recent studies have demonstrated acute changes in both symptoms and pulmonary function in asthmatics after only 1 hour of beach exposure to these aerosols. This study investigated if there were latent and/or sustained effects in asthmatics in the days following the initial beach exposure during periods with and without an active Florida red tide.Symptom data and spirometry data were collected before and after 1 hour of beach exposure. Subjects kept daily symptom diaries and measured their peak flow each morning for 5 days following beach exposure. During non-exposure periods, there were no significant changes in symptoms or pulmonary function either acutely or over 5 days of follow-up. After the beach exposure during an active Florida red tide, subjects had elevated mean symptoms which did not return to the pre-exposure baseline for at least 4 days. The peak flow measurements decreased after the initial beach exposure, decreased further within 24 hours, and continued to be suppressed even after 5 days. Asthmatics may continue to have increased symptoms and delayed respiratory function suppression for several days after 1 hour of exposure to the Florida red tide toxin aerosols.

  12. Exposure and Effect Assessment of Aerosolized Red Tide Toxins (Brevetoxins) and Asthma

    PubMed Central

    Fleming, Lora E.; Bean, Judy A.; Kirkpatrick, Barbara; Cheng, Yung Sung; Pierce, Richard; Naar, Jerome; Nierenberg, Kate; Backer, Lorraine C.; Wanner, Adam; Reich, Andrew; Zhou, Yue; Watkins, Sharon; Henry, Mike; Zaias, Julia; Abraham, William M.; Benson, Janet; Cassedy, Amy; Hollenbeck, Julie; Kirkpatrick, Gary; Clarke, Tainya; Baden, Daniel G

    2009-01-01

    Background In previous studies we demonstrated statistically significant changes in reported symptoms for lifeguards, general beach goers, and persons with asthma, as well as statistically significant changes in pulmonary function tests (PFTs) in asthmatics, after exposure to brevetoxins in Florida red tide (Karenia brevis bloom) aerosols. Objectives In this study we explored the use of different methods of intensive ambient and personal air monitoring to characterize these exposures to predict self-reported health effects in our asthmatic study population. Methods We evaluated health effects in 87 subjects with asthma before and after 1 hr of exposure to Florida red tide aerosols and assessed for aerosolized brevetoxin exposure using personal and ambient samplers. Results After only 1 hr of exposure to Florida red tide aerosols containing brevetoxin concentrations > 57 ng/m3, asthmatics had statistically significant increases in self-reported respiratory symptoms and total symptom scores. However, we did not see the expected corresponding changes in PFT results. Significant increases in self-reported symptoms were also observed for those not using asthma medication and those living ≥ 1 mile from the coast. Conclusions These results provide additional evidence of health effects in asthmatics from ambient exposure to aerosols containing very low concentrations of brevetoxins, possibly at the lower threshold for inducing a biologic response (i.e., toxicity). Consistent with the literature describing self-reported symptoms as an accurate measure of asthmatic distress, our results suggest that self-reported symptoms are a valuable measure of the extent of health effects from exposure to aerosolized brevetoxins in asthmatic populations. PMID:19654919

  13. Red Tide off Texas Coast

    NASA Technical Reports Server (NTRS)

    2002-01-01

    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

  14. Red Tide off Texas Coast

    NASA Technical Reports Server (NTRS)

    2002-01-01

    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

  15. Gastrointestinal Emergency Room Admissions and Florida Red Tide Blooms

    PubMed Central

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

    2009-01-01

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

  16. Gastrointestinal Emergency Room Admissions and Florida Red Tide Blooms.

    PubMed

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

    2010-01-01

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

  17. Public perceptions of Florida red tide risks.

    PubMed

    Kuhar, Sara E; Nierenberg, Kate; Kirkpatrick, Barbara; Tobin, Graham A

    2009-07-01

    This research integrates theoretical frameworks of risk perception, social amplification of risk, and the role of place-specific contexts in order to explore the various perceptions surrounding Florida red tides. Florida red tides are naturally occurring events that are increasing in frequency, duration, and severity. This has implications for public health, the local economy, and ecosystem health. While many of the negative impacts of Florida red tides are not easily controlled, some of the secondary impacts may be mitigated through individuals' responses. However, public perception and consequent reactions to Florida red tides have not been investigated. This research uses questionnaire surveys, and semi-structured interviews, to explore the various perceptions of the risk surrounding red tides. Surveys and interviews were conducted along two Florida west coast beaches. The results indicate that the underlying foundations of the social amplification of the risk framework are applicable to understanding how individuals form perceptions of risk relative to red tide events. There are key differences between the spatial locations of individuals and corresponding perceptions, indicating that place-specific contexts are essential to understanding how individuals receive and interpret risk information. The results also suggest that individuals may be lacking efficient and up-to-date information about Florida red tides and their impacts because of inconsistent public outreach. Overall, social and spatial factors appear to be influential as to whether individuals amplify or attenuate the risks associated with Florida red tides.

  18. Public Perceptions of Florida Red Tide Risks

    PubMed Central

    Kuhar, Sara E.; Nierenberg, Kate; Kirkpatrick, Barbara; Tobin, Graham A.

    2009-01-01

    This research integrates theoretical frameworks of risk perception, social amplification of risk, and the role of place-specific contexts in order to explore the various perceptions surrounding Florida red tides. Florida red tides are naturally occurring events that are increasing in frequency, duration, and severity. This has implications for public health, the local economy, and ecosystem health. While many of the negative impacts of Florida red tides are not easily controlled, some of the secondary impacts may be mitigated through individuals’ responses. However, public perception and consequent reactions to Florida red tides have not been investigated. This research uses questionnaire surveys, and semi-structured interviews, to explore the various perceptions of the risk surrounding red tides. Surveys and interviews were conducted along two Florida west coast beaches. The results indicate that the underlying foundations of the social amplification of the risk framework are applicable to understanding how individuals form perceptions of risk relative to red tide events. There are key differences between the spatial locations of individuals and corresponding perceptions, indicating that place-specific contexts are essential to understanding how individuals receive and interpret risk information. The results also suggest that individuals may be lacking efficient and up-to-date information about Florida red tides and their impacts because of inconsistent public outreach. Overall, social and spatial factors appear to be influential as to whether individuals amplify or attenuate the risks associated with Florida red tides. PMID:19392675

  19. The Art of Red Tide Science

    PubMed Central

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

    2012-01-01

    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

  20. The Art of Red Tide Science.

    PubMed

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

    2012-05-01

    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.

  1. Brevetoxicosis: red tides and marine mammal mortalities.

    PubMed

    Flewelling, Leanne J; Naar, Jerome P; Abbott, Jay P; Baden, Daniel G; Barros, Nélio B; Bossart, Gregory D; Bottein, Marie-Yasmine D; Hammond, Daniel G; Haubold, Elsa M; Heil, Cynthia A; Henry, Michael S; Jacocks, Henry M; Leighfield, Tod A; Pierce, Richard H; Pitchford, Thomas D; Rommel, Sentiel A; Scott, Paula S; Steidinger, Karen A; Truby, Earnest W; Van Dolah, Frances M; Landsberg, Jan H

    2005-06-09

    Potent marine neurotoxins known as brevetoxins are produced by the 'red tide' dinoflagellate Karenia brevis. They kill large numbers of fish and cause illness in humans who ingest toxic filter-feeding shellfish or inhale toxic aerosols. The toxins are also suspected of having been involved in events in which many manatees and dolphins died, but this has usually not been verified owing to limited confirmation of toxin exposure, unexplained intoxication mechanisms and complicating pathologies. Here we show that fish and seagrass can accumulate high concentrations of brevetoxins and that these have acted as toxin vectors during recent deaths of dolphins and manatees, respectively. Our results challenge claims that the deleterious effects of a brevetoxin on fish (ichthyotoxicity) preclude its accumulation in live fish, and they reveal a new vector mechanism for brevetoxin spread through food webs that poses a threat to upper trophic levels.

  2. Florida Red Tide Perception: Residents versus Tourists

    PubMed Central

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

    2010-01-01

    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

  3. Florida Red Tide Perception: Residents versus Tourists.

    PubMed

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

    2010-09-01

    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.

  4. In Brief: Red tide Web site

    NASA Astrophysics Data System (ADS)

    Showstack, Randy; Kumar, Mohi

    2008-06-01

    The U.S. National Oceanic and Atmospheric Administration has established the NOAA New England Red Tide Information Center to help people understand the significant red tides that are predicted to form there later this spring. The site (http://www.oceanservice.noaa.gov/redtide) will provide a summary of the current red tide situation and its potential harmful impacts on humans and animals and will serve as a central repository of information. The site also will have direct links to news releases, changes to relevant federal fishing regulations, links to closures of shellfish waters, and links to state agency Web sites with localized information. In addition, the site will have information about NOAA's scientific response effort as well as information from several other sources including NOAA's major response partner, the Woods Hole Oceanographic Institution (WHOI). On 24 April, WHOI scientists, using forecast models developed with NOAA funding support, predicted ``that excess winter precipitation has set the stage for a harmful algal bloom similar to the historic red tide of 2005.'' That bloom shut down shellfish beds from the Bay of Fundy to Martha's Vineyard for several months.

  5. Saharan dust and Florida red tides: The cyanophyte connection

    NASA Astrophysics Data System (ADS)

    Walsh, John J.; Steidinger, Karen A.

    2001-06-01

    Prediction of the consequences of harmful algal blooms for humans and other vertebrates is constrained by an inadequate understanding of the factors that promote their initiation. A simple exponential growth model of net production is used for analysis of four time series at different sampling intervals over ˜40 years of red tide strandings, associated fish kills, and concomitant dust loadings on the West Florida shelf. At least large summer blooms of a toxic dinoflagellate Gymnodinium breve appear to be primed regularly by an aeolian supply of nutrients. Wet deposition of Saharan mineral aerosols may alleviate iron limitation of diazotrophic cyanophytes, which in turn fuel the nitrogen economy of red tides in the eastern Gulf of Mexico. Vagaries of the wind-induced circulation and of selective grazing pressure on phytoplankton competitors within phosphorus replete coastal waters then determine each year the residence times for exposure of G. breve-mediated neurotoxins to fish, manatees, and humans along the southeastern United States.

  6. Environmental exposures to Florida red tides: Effects on emergency room respiratory diagnoses admissions.

    PubMed

    Kirkpatrick, Barbara; Fleming, Lora E; Backer, Lorraine C; Bean, Judy A; Tamer, Robert; Kirkpatrick, Gary; Kane, Terrance; Wanner, Adam; Dalpra, Dana; Reich, Andrew; Baden, Daniel G

    2006-10-01

    Human exposure to Florida red tides formed by Karenia brevis, occurs from eating contaminated shellfish and inhaling aerosolized brevetoxins. Recent studies have documented acute symptom changes and pulmonary function responses after inhalation of the toxic aerosols, particularly among asthmatics. These findings suggest that there are increases in medical care facility visits for respiratory complaints and for exacerbations of underlying respiratory diseases associated with the occurrence of Florida red tides.This study examined whether the presence of a Florida red tide affected the rates of admission with a respiratory diagnosis to a hospital emergency room in Sarasota, FL. The rate of respiratory diagnoses admissions were compared for a 3-month time period when there was an onshore red tide in 2001 (red tide period) and during the same 3-month period in 2002 when no red tide bloom occurred (non-red tide period). There was no significant increase in the total number of respiratory admissions between the two time periods. However, there was a 19% increase in the rate of pneumonia cases diagnosed during the red tide period compared with the non-red tide period. We categorized home residence zip codes as coastal (within 1.6 km from the shore) or inland (>1.6 km from shore). Compared with the non-red tide period, the coastal residents had a significantly higher (54%) rate of respiratory diagnoses admissions than during the red tide period. We then divided the diagnoses into subcategories (i.e. pneumonia, bronchitis, asthma, and upper airway disease). When compared with the non-red tide period, the coastal zip codes had increases in the rates of admission of each of the subcategories during the red tide period (i.e. 31, 56, 44, and 64%, respectively). This increase was not observed seen in the inland zip codes.These results suggest that the healthcare community has a significant burden from patients, particularly those who live along the coast, needing emergency

  7. Florida Red Tide Knowledge and Risk Perception: Is there a need for tailored messaging?

    PubMed Central

    Kirkpatrick, Barbara; Kohler, Kate; Byrne, Margaret M.; Studts, Jamie

    2013-01-01

    Harmful algal blooms of the toxic dinoflagellate, Karenia brevis, occur throughout the Gulf of Mexico. Recent research efforts sponsored by the National Institute of Environmental Health Sciences (NIEHS) and others found that Florida red tide causes both acute and possibly chronic health effects from the toxic aerosols. Florida red tide also demonstrated significant social and economic impacts to both coastal residents and visitors. In conjunction with the research, persistent outreach efforts were conducted over the 11 year period. The goal of this project was to assess potential needs for tailored messaging needed among different red tide information user groups. Survey participants included 303 local residents, both with asthma and without, and ‘snowbirds (seasonal residents that reside in the Sarasota area for more than 3 months but less than 6 months/year), also both with asthma and without. The questionnaire assessed Florida red tide knowledge and risk perception regarding Florida red tide using items drawn from two previously published surveys to allow comparison. Our results reveal that overall knowledge of Florida red tide has not changed. We found that knowledge was consistent across our selected groups and also did not vary by age, gender and education level. However, knowledge regarding consumption of seafood during Florida red tide has declined. Risk perception increased significantly for people who have asthma. Individuals responsible for public health communication regarding Florida red tide and human health concerns need to continue to pursue more effective outreach messages and delivery methods. PMID:24563634

  8. Florida Red Tide Knowledge and Risk Perception: Is there a need for tailored messaging?

    PubMed

    Kirkpatrick, Barbara; Kohler, Kate; Byrne, Margaret M; Studts, Jamie

    2014-02-01

    Harmful algal blooms of the toxic dinoflagellate, Karenia brevis, occur throughout the Gulf of Mexico. Recent research efforts sponsored by the National Institute of Environmental Health Sciences (NIEHS) and others found that Florida red tide causes both acute and possibly chronic health effects from the toxic aerosols. Florida red tide also demonstrated significant social and economic impacts to both coastal residents and visitors. In conjunction with the research, persistent outreach efforts were conducted over the 11 year period. The goal of this project was to assess potential needs for tailored messaging needed among different red tide information user groups. Survey participants included 303 local residents, both with asthma and without, and 'snowbirds (seasonal residents that reside in the Sarasota area for more than 3 months but less than 6 months/year), also both with asthma and without. The questionnaire assessed Florida red tide knowledge and risk perception regarding Florida red tide using items drawn from two previously published surveys to allow comparison. Our results reveal that overall knowledge of Florida red tide has not changed. We found that knowledge was consistent across our selected groups and also did not vary by age, gender and education level. However, knowledge regarding consumption of seafood during Florida red tide has declined. Risk perception increased significantly for people who have asthma. Individuals responsible for public health communication regarding Florida red tide and human health concerns need to continue to pursue more effective outreach messages and delivery methods.

  9. Frontiers in Outreach and Education: The Florida Red Tide Experience.

    PubMed

    Nierenberg, Kate; Hollenbeck, Julie; Fleming, Lora E; Stephan, Wendy; Reich, Andrew; Backer, Lorraine C; Currier, Robert; Kirkpatrick, Barbara

    2011-05-01

    To enhance information sharing and garner increased support from the public for scientific research, funding agencies now typically require that research groups receiving support convey their work to stakeholders. The National Institute of Environmental Health Sciences-(NIEHS) funded Aerosolized Florida Red Tide P01 research group (Florida Red Tide Research Group) has employed a variety of outreach strategies to meet this requirement. Messages developed from this project began a decade ago and have evolved from basic print material (fliers and posters) to an interactive website, to the use of video and social networking technologies, such as Facebook and Twitter. The group was able to track dissemination of these information products; however, evaluation of their effectiveness presented much larger challenges. The primary lesson learned by the Florida Red Tide Research Group is that the best ways to reach specific stakeholders is to develop unique products or services to address specific stakeholders needs, such as the Beach Conditions Reporting System. Based on the experience of the Group, the most productive messaging products result when scientific community engages potential stakeholders and outreach experts during the very initial phases of a project.

  10. Frontiers in Outreach and Education: The Florida Red Tide Experience

    PubMed Central

    Nierenberg, Kate; Hollenbeck, Julie; Fleming, Lora E.; Stephan, Wendy; Reich, Andrew; Backer, Lorraine C.; Currier, Robert; Kirkpatrick, Barbara

    2011-01-01

    To enhance information sharing and garner increased support from the public for scientific research, funding agencies now typically require that research groups receiving support convey their work to stakeholders. The National Institute of Environmental Health Sciences-(NIEHS) funded Aerosolized Florida Red Tide P01 research group (Florida Red Tide Research Group) has employed a variety of outreach strategies to meet this requirement. Messages developed from this project began a decade ago and have evolved from basic print material (fliers and posters) to an interactive website, to the use of video and social networking technologies, such as Facebook and Twitter. The group was able to track dissemination of these information products; however, evaluation of their effectiveness presented much larger challenges. The primary lesson learned by the Florida Red Tide Research Group is that the best ways to reach specific stakeholders is to develop unique products or services to address specific stakeholders needs, such as the Beach Conditions Reporting System. Based on the experience of the Group, the most productive messaging products result when scientific community engages potential stakeholders and outreach experts during the very initial phases of a project. PMID:21532966

  11. Population dynamics of red tide dinoflagellates

    NASA Astrophysics Data System (ADS)

    Wyatt, Timothy; Zingone, Adriana

    2014-03-01

    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 (μ) of the vegetative phase. It is argued that r is strategically adapted to seasonal cycles and long term environmental variability, while μ reflects tactical needs (timing) and constraints (grazers, parasites) on vegetative growth.

  12. Hydroxyl radical generation by red tide algae.

    PubMed

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

    1992-04-01

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

  13. Red Tide Strands South African Rock Lobsters

    NASA Technical Reports Server (NTRS)

    2002-01-01

    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

  14. Red Tide Strands South African Rock Lobsters

    NASA Technical Reports Server (NTRS)

    2002-01-01

    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

  15. Red Tide Strands South African Rock Lobsters

    NASA Technical Reports Server (NTRS)

    2002-01-01

    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

  16. Red Tide Strands South African Rock Lobsters

    NASA Technical Reports Server (NTRS)

    2002-01-01

    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

  17. Vibrios associated with red tides caused by Mesodinium rubrum.

    PubMed Central

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

    1990-01-01

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

  18. Spectral characteristics analysis of red tide water in mesocosm experiment

    NASA Astrophysics Data System (ADS)

    Cui, Tingwei; Zhang, Jie; Zhang, Hongliang; Ma, Yi; Gao, Xuemin

    2003-05-01

    Mesocosm ecosystem experiment with seawater enclosed of the red tide was carried out from July to September 2001. We got four species of biology whose quantities of bion are dominant in the red tide. During the whole process from the beginning to their dying out for every specie, in situ spectral measurements were carried out. After data processing, characteristic spectra of red tide of different dominant species are got. Via comparison and analysis of characteristics of different spectra, we find that in the band region between 685 and 735 nanometers, spectral characteristics of red tide is apparently different from that of normal water. Compared to spectra of normal water, spectra of red tide have a strong reflectance peak in the above band region. As to spectra of red tide dominated by different species, the situations of reflectance peaks are also different: the second peak of Mesodinium rubrum spectrum lies between 726~732 nm, which is more than 21nm away from the other dominant species spectra"s Leptocylindrus danicus"s second spectral peak covers 686~694nm; that of Skeletonema costatum lies between 691~693 nm. Chattonella marina"s second spectral peak lies about 703~705 nm. Thus we can try to determine whether red tide has occurred according to its spectral data. In order to monitor the event of red tide and identify the dominant species by the application of the technology of hyperspectral remote sensing, acquiring spectral data of different dominant species of red tide as much as possible becomes a basic work to be achieved for spectral matching, information extraction and so on based on hyperspectral data.

  19. Literature Review of Florida Red Tide: Implications for Human Health Effects

    PubMed Central

    Kirkpatrick, Barbara; Fleming, Lora E.; Squicciarini, Dominick; Backer, Lorrie C.; Clark, Richard; Abraham, William; Benson, Janet; Cheng, Yung Sung; Johnson, David; Pierce, Richard; Zaias, Julia; Bossart, Gregory D.; Baden, Daniel G.

    2010-01-01

    Florida red tides are a natural phenomenon caused by dense aggregations of single cell or several species of unicellular organisms. Patches of discolored water, dead or dying fish, and respiratory irritants in the air often characterize these algal blooms. In humans, two distinct clinical entities, depending on the route of exposure, are associated with exposure to the Florida red tide toxins (particularly the brevetoxins). With the ingestion of brevetoxin-contaminated shellfish, neurotoxic shellfish poisoning (NSP) presents as a milder gastroenteritis with neurologic symptoms compared with other marine toxin diseases such as paralytic shellfish poisoning (PSP) or ciguatera fish poisoning. With the inhalation of the aerosolized red tide toxins (especially the brevetoxins) from the sea spray, respiratory irritation and possibly other health effects are reported in both humans and other mammals (Baden 1995, Fleming 1998a, Fleming 1998b, Fleming 1999a, Bossart 1998, Asai 1982, Eastaugh 1989, Pierce 1986, Music 1973, Temple 1995, Anderson 1994). This paper reviews the literature on the known and possible human health effects of exposure to the Florida red tides and their toxins. The review includes discussion of the red tide organisms and their toxins, as well as the effects of these toxins on both wild and laboratory animals as they relate to possible human health effects and exposures. PMID:20411030

  20. Detection of red tide events in the Ariake Sound, Japan

    NASA Astrophysics Data System (ADS)

    Ishizaka, Joji

    2003-05-01

    High resolution SeaWiFS data was used to detect a red tide event occurred in the Ariake Sound, Japan, in winter of 2000 to 2001. The area is small embayment surrounding by tidal flat, and it is known as one of the most productive areas in coast of Japan. The red tide event damaged to seaweed (Nori) culture, and the relation to the reclamation at the Isahaya Bay in the Sound has been discussed. SeaWiFS chlorophyll data showed the red tide started early December 2000, from the Isahaya Bay, although direct relationship to the reclamation was not clear. The red tide persisted to the end of February. Monthly average of SeaWiFS data from May 1998 to December 2001 indicated that the chlorophyll increased twice a year, early summer and fall after the rain. The red tide event was part of the fall bloom which started later and continued longer than other years. Ocean color is useful to detect the red tide; however, it is required to improve the algorithms to accurately estimate chlorophyll in high turbid water and to discriminate toxic flagellates.

  1. Florida Red Tide Toxins (Brevetoxins) and Longitudinal Respiratory Effects in Asthmatics

    PubMed Central

    Bean, Judy A.; Fleming, Lora E.; Kirkpatrick, Barbara; Backer, Lorraine C.; Nierenberg, Kate; Reich, Andrew; Cheng, Yung Sung; Wanner, Adam; Benson, Janet; Naar, Jerome; Pierce, Richard; Abraham, William M.; Kirkpatrick, Gary; Hollenbeck, Julie; Zaias, Julia; Mendes, Eliana; Baden, Daniel G.

    2011-01-01

    Having demonstrated significant and persistent adverse changes in pulmonary function for asthmatics after 1 hour exposure to brevetoxins in Florida red tide (Karenia brevis bloom) aerosols, we assessed the possible longer term health effects in asthmatics from intermittent environmental exposure to brevetoxins over 7 years. 125 asthmatic subjects were assessed for their pulmonary function and reported symptoms before and after 1 hour of environmental exposure to Florida red tide aerosols for upto 11 studies over seven years. As a group, the asthmatics came to the studies with normal standardized percent predicted pulmonary function values. The 38 asthmatics who participated in only one exposure study were more reactive compared to the 36 asthmatics who participated in ≥4 exposure studies. The 36 asthmatics participating in ≥4 exposure studies demonstrated no significant change in their standardized percent predicted pre-exposure pulmonary function over the 7 years of the study. These results indicate that stable asthmatics living in areas with intermittent Florida red tides do not exhibit chronic respiratory effects from intermittent environmental exposure to aerosolized brevetoxins over a 7 year period. PMID:22053149

  2. Encystment and excystment of Gonyaulax polyedra during a red tide

    NASA Astrophysics Data System (ADS)

    Marasović, Ivona

    1989-01-01

    As part of long term research program on red tide phenomena in the Kaštela Bay (Adriatic Sea), the formation of temporary cysts of Gonyaulax polyedra Stein was investigated. These cysts formed only when ambient conditions changed dramatically (O 2 depletion, pH decrease), coinciding in time with the occurrence of mass mortalities of marine fauna. The data suggest that temporary cysts act as a protective mechanism for this organism, which, by reducing its metabolic activity, is able to survive in a latent state during unfavourable conditions. It appears, that this mechanism is important in relation to the persistence and recurrence of red tides in this area throughout the summer.

  3. [Temporal and spatial distribution of red tide in Yangtze River Estuary and adjacent waters].

    PubMed

    Liu, Lu-San; Li, Zi-Cheng; Zhou, Juan; Zheng, Bing-Hui; Tang, Jing-Liang

    2011-09-01

    The events of red tide were collected in Yangtze River Estuary and adjacent waters from 1972 to 2009. Based on geographic information system (GIS) analysis on the temporal and spatial distribution of red tide, the distribution map was generated accordingly. The results show: (1) There are three red tide-prone areas, which are outside the Yangtze River estuary and the eastern of Sheshan, Huaniaoshan-Shengshan-Gouqi, Zhoushan and the eastern of Zhujiajian. The red tide occurred 174 times in total, in which there were 25 times covered the area was larger than 1 000 km2. After 2000, the frequency of red tide were significantly increasing; (2) The frequent occurrence of red tide was in May (51% of total occurrence) and June (20% of total occurrence); (3) In all of the red tide plankton, the dominant species were Prorocentrum danghaiense, Skeletonema costatum, Prorocentrum dantatum, Nactiluca scientillans. The red tides caused by these species were 38, 35, 15, 10 times separately.

  4. [Mechanisms of removing red tide organisms by organo-clays].

    PubMed

    Cao, Xi-Hua; Song, Xiu-Xian; Yu, Zhi-Ming; Wang, Kui

    2006-08-01

    We tested the influence of the preparation conditions of the quaternary ammonium compounds (QACs) modified clays on their capacities to remove red tide organisms, then discussed the mechanisms of the organo-clays removing red tide organisms. Hexadecyltrimethylammonium (HDTMA) improved the capacity of clays to flocculate red tide algae, and the HDTMA in metastable state enhanced the toxicity of the clay complexes to algae. The capacities of the organo-clays correlated with the toxicity and the adsorbed amount of the QACs used in clays modification, but as the incubation time was prolonged the stability of the organo-clays was improved and the algal removal efficiencies of the clay complexes decreased. When the adsorbed HDTMA was arranged in different clays in which the spatial resistance was different, there was more HDTMA in metastable state in the three-layer montmorillonite. Because of the homo-ion effect the bivalent or trivalent metal ions induced more HDTMA in metastable state and the corresponding organo-clays had high capacities to remove red tide organisms. When the reaction temperature was 60 degrees C the adsorbed HDTMA was easily arranged on cation exchange sites, if the temperature rose or fell the metastable HDTMA would increase so that the capacity of the clays was improved.

  5. Detecting the red tide based on remote sensing data in optically complex East China Sea

    NASA Astrophysics Data System (ADS)

    Xu, Xiaohui; Pan, Delu; Mao, Zhihua; Tao, Bangyi; Liu, Qiong

    2012-09-01

    Red tide not only destroys marine fishery production, deteriorates the marine environment, affects coastal tourist industry, but also causes human poison, even death by eating toxic seafood contaminated by red tide organisms. Remote sensing technology has the characteristics of large-scale, synchronized, rapid monitoring, so it is one of the most important and most effective means of red tide monitoring. This paper selects the high frequency red tides areas of the East China Sea as study area, MODIS/Aqua L2 data as the data source, analysis and compares the spectral differences in the red tide water bodies and non-red tide water bodies of many historical events. Based on the spectral differences, this paper develops the algorithm of Rrs555/Rrs488> 1.5 to extract the red tide information. Apply the algorithm on red tide event happened in the East China Sea on May 28, 2009 to extract the information of red tide, and found that the method can determine effectively the location of the occurrence of red tide; there is a good corresponding relationship between red tide extraction result and chlorophyll a concentration extracted by remote sensing, shows that these algorithm can determine effectively the location and extract the red tide information.

  6. The recognition of ocean red tide with hyper-spectral-image based on EMD

    NASA Astrophysics Data System (ADS)

    Zhao, Wencang; Wei, Hongli; Shi, Changjiang; Ji, Guangrong

    2008-05-01

    A new technique is introduced in this paper regarding red tide recognition with remotely sensed hyper-spectral images based on empirical mode decomposition (EMD), from an artificial red tide experiment in the East China Sea in 2002. A set of characteristic parameters that describe absorbing crest and reflecting crest of the red tide and its recognition methods are put forward based on general picture data, with which the spectral information of certain non-dominant alga species of a red tide occurrence is analyzed for establishing the foundation to estimate the species. Comparative experiments have proved that the method is effective. Meanwhile, the transitional area between red-tide zone and non-red-tide zone can be detected with the information of thickness of algae influence, with which a red tide can be forecast.

  7. Some dinophycean red tide plankton species generate a superoxide scavenging substance.

    PubMed

    Sato, Emiko; Niwano, Yoshimi; Matsuyama, Yukihiko; Kim, Daekyung; Nakashima, Takuji; Oda, Tatsuya; Kohno, Masahiro

    2007-03-01

    Recent studies indicate that some raphidophycean red tide flagellates produce substances able to scavenge superoxide, whereas there have been no reports on superoxide scavenger production by dinophycean red tide flagellates. In this study, we examined the superoxide-scavenging activity of aqueous extracts from dinophycean red tide flagellates, Gymnodinium spp., Scrippsiella trochoidea, and Karenia sp., by a luminol analog L-012-dependent chemiluminescence (CL) method and an electron spin resonance (ESR)-spin trapping method, and compared the activity to that of raphidophycean red tide flagellates, Chattonella spp., Heterosigma akashiwo, and Fibrocapsa japonica. In the experiment applying the L-012-dependent CL method, only the aqueous extracts from raphidophycean red tide flagellates showed superoxide-scavenging activity. On the other hand, applying the ESR-spin trapping method, we found that the aqueous extracts from dinophycean red tide flagellates also showed superoxide-scavenging activity. This is the first report on the production of a superoxide-scavenger by dinophycean red tide flagellates.

  8. Study of red tide prediction model for the Changjiang Estuary

    NASA Astrophysics Data System (ADS)

    Wang, Zheng-Fang; Lu, Hai-Yan; Zhang, Qing; Lu, Yong; Zeng, Jiang-Ning; Zhou, Qing-Song

    2000-12-01

    This paper based on field data (on red tide water quality monitoring at the Chaggjiang River mouth and Hutoudu mariculture area in Zhejiang Province from May to August in 1995, and May to September in 1996) presents an effective model for short term prediction of red tide in the Changjiang Estuary. The measured parameters include: depth, temperature, color diaphaneity, density, DO, COD and nutrients (PO4-P, NO2-N, NO3-N, NH4-N). The model was checked by field-test data, and compared with other related models. The model: Z=SAL-3.95 DO-2.974 PH-5.421 PO4-P is suitable for application to the Shengsi aquiculture area near the Changjiang Estuary.

  9. Review of Florida Red Tide and Human Health Effects

    PubMed Central

    Fleming, Lora E.; Kirkpatrick, Barbara; Backer, Lorraine C.; Walsh, Cathy J.; Nierenberg, Kate; Clark, John; Reich, Andrew; Hollenbeck, Julie; Benson, Janet; Cheng, Yung Sung; Naar, Jerome; Pierce, Richard; Bourdelais, Andrea J; Abraham, William M.; Kirkpatrick, Gary; Zaias, Julia; Wanner, Adam; Mendes, Eliana; Shalat, Stuart; Hoagland, Porter; Stephan, Wendy; Bean, Judy; Watkins, Sharon; Clarke, Tainya; Byrne, Margaret; Baden, Daniel G.

    2010-01-01

    This paper reviews the literature describing research performed over the past decade on the known and possible exposures and human health effects associated with Florida red tides. These harmful algal blooms are caused by the dinoflagellate, Karenia brevis, and similar organisms, all of which produce a suite of natural toxins known as brevetoxins. Florida red tide research has benefited from a consistently funded, long term research program, that has allowed an interdisciplinary team of researchers to focus their attention on this specific environmental issue—one that is critically important to Gulf of Mexico and other coastal communities. This long-term interdisciplinary approach has allowed the team to engage the local community, identify measures to protect public health, take emerging technologies into the field, forge advances in natural products chemistry, and develop a valuable pharmaceutical product. The Review includes a brief discussion of the Florida red tide organisms and their toxins, and then focuses on the effects of these toxins on animals and humans, including how these effects predict what we might expect to see in exposed people. PMID:21218152

  10. Hurricanes, submarine groundwater discharge, and Florida's red tides

    NASA Astrophysics Data System (ADS)

    Hu, Chuanmin; Muller-Karger, Frank E.; Swarzenski, Peter W.

    2006-06-01

    A Karenia brevis Harmful Algal Bloom affected coastal waters shallower than 50 m off west-central Florida from January 2005 through January 2006, showing a sustained anomaly of ~1 mg chlorophyll m-3 over an area of up to 67,500 km2. Red tides occur in the same area (approximately 26-29°N, 82-83°W) almost every year, but the intense 2005 bloom led to a widespread hypoxic zone (dissolved oxygen <2 mg L-1) that caused mortalities of benthic communities, fish, turtles, birds, and marine mammals. Runoff alone provided insufficient nitrogen to support this bloom. We pose the hypothesis that submarine groundwater discharge (SGD) provides the missing nutrients, and indeed can trigger and support the recurrent red tides off west-central Florida. SGD inputs of dissolved inorganic nitrogen (DIN) in Tampa Bay alone are ~35% of that discharged by all central Florida rivers draining west combined. We propose that the unusual number of hurricanes in 2004 resulted in high runoff, and in higher than normal SGD emerging along the west Florida coast throughout 2005, initiating and fueling the persistent HAB. This mechanism may also explain recurrent red tides in other coastal regions of the Gulf of Mexico.

  11. Review of Florida Red Tide and Human Health Effects.

    PubMed

    Fleming, Lora E; Kirkpatrick, Barbara; Backer, Lorraine C; Walsh, Cathy J; Nierenberg, Kate; Clark, John; Reich, Andrew; Hollenbeck, Julie; Benson, Janet; Cheng, Yung Sung; Naar, Jerome; Pierce, Richard; Bourdelais, Andrea J; Abraham, William M; Kirkpatrick, Gary; Zaias, Julia; Wanner, Adam; Mendes, Eliana; Shalat, Stuart; Hoagland, Porter; Stephan, Wendy; Bean, Judy; Watkins, Sharon; Clarke, Tainya; Byrne, Margaret; Baden, Daniel G

    2011-01-01

    This paper reviews the literature describing research performed over the past decade on the known and possible exposures and human health effects associated with Florida red tides. These harmful algal blooms are caused by the dinoflagellate, Karenia brevis, and similar organisms, all of which produce a suite of natural toxins known as brevetoxins. Florida red tide research has benefited from a consistently funded, long term research program, that has allowed an interdisciplinary team of researchers to focus their attention on this specific environmental issue-one that is critically important to Gulf of Mexico and other coastal communities. This long-term interdisciplinary approach has allowed the team to engage the local community, identify measures to protect public health, take emerging technologies into the field, forge advances in natural products chemistry, and develop a valuable pharmaceutical product. The Review includes a brief discussion of the Florida red tide organisms and their toxins, and then focuses on the effects of these toxins on animals and humans, including how these effects predict what we might expect to see in exposed people.

  12. Hurricanes, submarine groundwater discharge, and Florida's red tides

    USGS Publications Warehouse

    Hu, C.; Muller-Karger, F. E.; Swarzenski, P.W.

    2006-01-01

    A Karenia brevis Harmful Algal Bloom affected coastal waters shallower than 50 m off west-central Florida from January 2005 through January 2006, showing a sustained anomaly of ???1 mg chlorophyll m-3 over an area of up to 67,500 km2. Red tides occur in the same area (approximately 26-29??N, 82-83??W) almost every year, but the intense 2005 bloom led to a widespread hypoxic zone (dissolved oxygen <2 mg L-1) that caused mortalities of benthic communities, fish, turtles, birds, and marine mammals. Runoff alone provided insufficient nitrogen to support this bloom. We pose the hypothesis that submarine groundwater discharge (SGD) provides the missing nutrients, and indeed can trigger and support the recurrent red tides off west-central Florida. SGD inputs of dissolved inorganic nitrogen (DIN) in Tampa Bay alone are ???35% of that discharged by all central Florida rivers draining west combined. We propose that the unusual number of hurricanes in 2004 resulted in high runoff, and in higher than normal SGD emerging along the west Florida coast throughout 2005, initiating and fueling the persistent HAB. This mechanism may also explain recurrent red tides in other coastal regions of the Gulf of Mexico. Copyright 2006 by the American Geophysical Union.

  13. [Retrieve of red tide distributions from MODIS data based on the characteristics of water spectrum].

    PubMed

    Qiu, Zhong-Feng; Cui, Ting-Wei; He, Yi-Jun

    2011-08-01

    After comparing the spectral differences between red tide water and normal water, we developed a method to retrieve red tide distributions from MODIS data based on the characteristics of red tide water spectrum. The authors used the 119 series of in situ observations to validate the method and found that only one observation has not been detected correctly. The authors then applied this method to MODIS data on April 4, 2005. In the research areas three locations of red tide water were apparently detected with the total areas about 2 000 km2. The retrieved red tide distributions are in good agreement with the distributions of high chlorophyll a concentrations. The research suggests that the method is available to eliminating the influence of suspended sediments and can be used to retrieve the locations and areas of red tide water.

  14. [Analysis on characteristics of red tide in Fujian coastal waters during the last 10 years].

    PubMed

    Li, Xue-Ding

    2012-07-01

    There were 161 red tide events collected during the last 10 years from 2001 to 2010 in Fujian coastal waters. Comprehensive analysis was performed using statistical methods and the results indicated the following characteristics of the temporal and spatial distribution of red tide in Fujian coastal waters: (1) Outbreaks of red tide often occurred between April and September, and the peak period was in May and June. Most red tide events lasted for 2 to 4 days, and the affected area was below 50 square kilometers. The first outbreak of red tide tended to occur earlier in recent years, and the lasting time became longer. (2) There were 20 species of organisms causing the red tides in Fujian coastal waters, among which 10 species were Bacillariophyta, 9 species were Dinophyta and 1 species was Protozoa. Prorocentrum donghaiense was the most frequent cause of red tides, followed by Noctiluca scintillans, Skeletonema costatum and Chaetoceros sp.. The species caused red tides obeyed the succession law and there were always new species involved. (2) In terms of spatial distribution, outbreaks of red tides mainly occurred in the coastal waters of Ningde, Fuzhou and Xiamen. The species causing red tides were Prorocentrum donghaiense and Noctiluca in the coastal waters in the north of Pingtan, Fujian Province, Skeletonema costatum and Chaetoceros in the coastal waters in the south of Pingtan, Fujian Province. The comprehensive analysis of the characteristics of red tides during the last 10 years is expected to provide scientific and reasonable basis for the prevention, reduction and forecast of red tides in Fujian coastal waters.

  15. [Removal of red tide organisms by organo-modified bentonite].

    PubMed

    Deng, Yuesong; Xu, Zirong; Xia, Meisheng; Ye, Ying; Hu, Caihong

    2004-01-01

    A series of organo-bentonites were synthesized by exchanging cation surfactants such as cyltrimethylammonium bromide and cetyltrimethylammonium to remove red tide organisms Skeletonema costatum. The results showed that the removal rate of Skeletonema costatum by the bentonites was in the order of cyltrimethylammonium surfactant modified iron pillared bentonite > cetyltrimethylammoium surfactant modified iron pillared bentonite > iron pillared bentonite > cyltrimethylammonium surfactant modified sodium bentonite > cetyltrimethylammoium surfactant modified > sodium bentonite. The removal rate of Skeletonema costatum was related to the length of alkyl chains and the amount of cation surfactants exchanged on bentonites.

  16. Red tide detection by means of peak shift of remote sensing reflectance and possibility of red tide detection with polarized radiance measurements

    NASA Astrophysics Data System (ADS)

    Arai, Kohei; Terayama, Yasunori

    2010-11-01

    A method for detection of red tide by means of remote sensing reflectance peak shift is proposed together with suspended solid influence eliminations. Although remote sensing reflectance peak is situated at around 550nm for sea water without suffered from red tide, the peak is shifted to the longer wavelength when sea water is suffered from red tide. Based on this fact, it is capable to detect red tide using high wavelength resolution of spectral-radiometers. The proposed system uses web camera with band-pass filter on the optics surface. Acquired imagery data can be transmitted through wireless LAN to Internet terminal and can be archived in server through Internet. Validity of the proposed method is confirmed with the system deployed in Ariake Sea which is situated in northern Kyushu, Japan. Also a method for red tide detection with satellite imagery data is attempted with suspended solid influence eliminations. Furthermore, a possibility of red tide detection with polarized radiance measurements is discussed through polarization camera derived sue surface imagery data, in particular, for non-spherical shape of red tide.

  17. Risk in daily newspaper coverage of red tide blooms in Southwest Florida.

    PubMed

    Li, Zongchao; Garrison, Bruce; Ullmann, Steven G; Kirkpatrick, Barbara; Fleming, Lora E; Hoagland, Porter

    This study investigated newspaper coverage of Florida red tide blooms in four metropolitan areas of Southwest Florida during a 25-year period, 1987-2012. We focused on how journalists framed red tide stories with respect to environmental risk, health risk, and economic risk. We determined risk to be a key factor in this news coverage, being an aspect of coverage of red tide itself in terms of environmental risk, tourism risk, and public health risk. The study found that red tide news coverage is most often framed as an environmental story.

  18. Risk in daily newspaper coverage of red tide blooms in Southwest Florida

    PubMed Central

    Li, Zongchao; Garrison, Bruce; Ullmann, Steven G.; Kirkpatrick, Barbara; Fleming, Lora E.; Hoagland, Porter

    2016-01-01

    This study investigated newspaper coverage of Florida red tide blooms in four metropolitan areas of Southwest Florida during a 25-year period, 1987-2012. We focused on how journalists framed red tide stories with respect to environmental risk, health risk, and economic risk. We determined risk to be a key factor in this news coverage, being an aspect of coverage of red tide itself in terms of environmental risk, tourism risk, and public health risk. The study found that red tide news coverage is most often framed as an environmental story. PMID:27087790

  19. Florida Red Tides, Manatee Brevetoxicosis, and Lung Models

    PubMed Central

    Kirkpatrick, Barbara; Colbert, Debborah E.; Dalpra, Dana; Newton, Elizabeth A. C.; Gaspard, Joseph; Littlefield, Brandi; Manire, Charles

    2010-01-01

    In 1996, 149 Florida manatees, Trichechus manatus latirostris, died along the southwest coast of Florida. Necropsy pathology results of these animals indicated that brevetoxin from the Florida red tide, Karenia brevis, caused their death. A red tide bloom had been previously documented in the area where these animals stranded. The necropsy data suggested the mortality occurred from chronic inhalation and/or ingestion. Inhalation theories include high doses of brevetoxin deposited/stored in the manatee lung or significant manatee sensitivity to the brevetoxin. Laboratory models of the manatee lungs can be constructed from casts of necropsied animals for further studies; however, it is necessary to define the breathing pattern in the manatee, specifically the volumes and flow rates per breath to estimate toxin deposition in the lung. To obtain this information, two captive-born Florida manatees, previously trained for husbandry and research behaviors, were trained to breathe into a plastic mask placed over their nares. The mask was connected to a spirometer that measured volumes and flows in situ. Results reveal high volumes, short inspiratory and expiratory times and high flow rates, all consistent with observed breathing patterns. PMID:26448968

  20. Florida Red Tides, Manatee Brevetoxicosis, and Lung Models.

    PubMed

    Kirkpatrick, Barbara; Colbert, Debborah E; Dalpra, Dana; Newton, Elizabeth A C; Gaspard, Joseph; Littlefield, Brandi; Manire, Charles

    In 1996, 149 Florida manatees, Trichechus manatus latirostris, died along the southwest coast of Florida. Necropsy pathology results of these animals indicated that brevetoxin from the Florida red tide, Karenia brevis, caused their death. A red tide bloom had been previously documented in the area where these animals stranded. The necropsy data suggested the mortality occurred from chronic inhalation and/or ingestion. Inhalation theories include high doses of brevetoxin deposited/stored in the manatee lung or significant manatee sensitivity to the brevetoxin. Laboratory models of the manatee lungs can be constructed from casts of necropsied animals for further studies; however, it is necessary to define the breathing pattern in the manatee, specifically the volumes and flow rates per breath to estimate toxin deposition in the lung. To obtain this information, two captive-born Florida manatees, previously trained for husbandry and research behaviors, were trained to breathe into a plastic mask placed over their nares. The mask was connected to a spirometer that measured volumes and flows in situ. Results reveal high volumes, short inspiratory and expiratory times and high flow rates, all consistent with observed breathing patterns.

  1. Research on red tide occurrences using enclosed experimental ecosystems in west Xiamen Harbor, China—Relationship between various factors and red tide occurrences

    NASA Astrophysics Data System (ADS)

    Lin, Yu; Harrison, P. J.

    2000-06-01

    A series of enclosed ecosystem experiments were conducted in a land-based tank near the seaside of West Xiamen Harbor. The results of experiments conducted in different seasons and years showed a repeatable phytoplankton succession. In this relatively stable ecosystem with added nutrients and trace metals, diatoms dominated initially, dinoflagellates dominated in the later stage, and dinoflagellate red tides eventually occurred. Vitamin B12 enrichment may speed up this succession process. Stirring the water column could stop this process. Soluble Mn at a level of 3 4 μg/L in seawater, which also is the existing concentration of soluble Mn in Xiamen Harbor seawater, is sufficient for the multiplication of algae and occurrence of red tide. The present study showed that excessive soluble Mn in Xiamen Harbor cannot cause red tide, and that Fe was one of the important factors causing diatiom red tide in this present study.

  2. Risk in Daily Newspaper Coverage of Red Tide Blooms in Southwest Florida

    ERIC Educational Resources Information Center

    Li, Zongchao; Garrison, Bruce; Ullmann, Steven G.; Kirkpatrick, Barbara; Fleming, Lora E.; Hoagland, Porter

    2015-01-01

    This study investigated newspaper coverage of Florida red tide blooms in four metropolitan areas of Southwest Florida during a 25-year period, 1987-2012. We focused on how journalists framed red tide stories with respect to environmental risk, health risk, and economic risk. We determined risk to be a key factor in this news coverage, being an…

  3. Risk in Daily Newspaper Coverage of Red Tide Blooms in Southwest Florida

    ERIC Educational Resources Information Center

    Li, Zongchao; Garrison, Bruce; Ullmann, Steven G.; Kirkpatrick, Barbara; Fleming, Lora E.; Hoagland, Porter

    2015-01-01

    This study investigated newspaper coverage of Florida red tide blooms in four metropolitan areas of Southwest Florida during a 25-year period, 1987-2012. We focused on how journalists framed red tide stories with respect to environmental risk, health risk, and economic risk. We determined risk to be a key factor in this news coverage, being an…

  4. BLOOMING MECHANISM OF FRESHWATER RED-TIDE IN EUTRORHIC ABOLISHED-RIVER

    NASA Astrophysics Data System (ADS)

    Nagabayashi, Hisao; Hirayama, Kazuo; Horikawa, Kunihiko

    This paper analyzes blooming mechanism of freshwater red-tide in an abolished-river which eutrophicated by seventy-years. Outbreaks of red tide of the river is depend on two phenomenon; the first one is the effect of secondary current generated by the wind along with the temperature rise, the second is the flow for the downstream by the release discharge from the power generation-dam in the downstream. Euglena spp. in euglena and Uroglena spp. in yellow-zooxanthellas is clarified to be the dominant species of the freshwater red-tide.

  5. A Plan to Develop a Red Tide Warning System for Seawater Desalination Process Management

    NASA Astrophysics Data System (ADS)

    Kim, Tae Woo; Yun, Hong Sik

    2017-04-01

    The holt of the seawater desalination process for fifty five days due to the eight-month long red tide in 2008 in the Persian Gulf, the Middle East, had lost about 10 billion KRW. The POSCO Seawater Desalination facility, located in Gwangyang Bay Area in the Southern Sea, has produced 30,000 tons of fresh water per day since 2014. Since there has been an incident of red time in the area for three months in August, 2012, it is necessary to establish a warning system for red tide that threatens the stable operation of the seawater desalination facility. A red tide warning system can offer the seawater desalination facility manager customized services on red tide information and potential red tide inflow to the water intake. This study aimed to develop a red tide warning system in Gwangyang Bay Area by combining RS, modeling and monitoring technologies, which provides red tide forecasting information with which to effectively control the seawater desalination process. Using the proposed system, the seawater desalination facility manager can take phased measures to cope with the inflow of red tide. ACKNOWLEDGMENTS This research was supported by a grant(16IFIP-C088924-03) from Industrial Facilities & Infrastructure Research Program funded by Ministry of Land, Infrastructure and Transport(MOLIT) of the Korea government and the Korea Agency for Infrastructure Technology Advancement (KAIA). This research was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education(NRF-2014R1A1A2054975).

  6. Amino acids release in two red tide events in Chinese coastal waters

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Chen, J.; Jin, H.

    2013-12-01

    During two red tide events and in situ experiments the East China Sea and the Pearl River Estuary, we analyzed DOC, POC, dissolved free amino acids (DFAA), dissolved combined amino acids (DCAA) and particulate hydrolysable amino acids (PHAA) and nutrients in samples from red tides areas as well as surrounding waters. The results show that POC and PHAA in red tide waters increased dramatically by about one order compared with those in surrounding waters. DCAA, DFAA and DOC also increased in red tide waters but only less than 2 folds increasing were observed. DFAA was only accounted for less than 5% of total amino acids (DFAA+DCAA+PHAA) and varied distinctly for all samples. Particulate organic carbon presented as amino acids (PHAA-C/POC) was accounted for about 35-60% of POC while dissolved organic carbon presented as amino acids (DCAA-C/DOC) was accounted for about 20-30% of DOC. Organic carbon pool shifted from DOC dominating at normal waters to POC dominating during red tides. During red tide most inorganic nitrogen nutrients (NO3+NO2) was seemly transformed into amino acids (here we called PHAA-N, DCAA-N, DFAA-N), in particular PHAA. Molecular composition of amino acids in organic matter suggested that POC mainly derived from phytoplankton in red tide waters, but the percentages of zooplanton and bacterial derived POC or DOC increased after one week of red tide. Our observations suggest that amino acids actually act as intergradation of nitrogen nutrients regeneration. We hypothesize that although zooplankton grazing and bacterial activities could lead to transformation of amino acids from phytoplankton into zooplankton and bacterial as well as from particulate organic matter into dissolved organic matter, nitrogen still present in its organic pool thus delay the regeneration of inorganic nitrogen.

  7. Analysis of change of red tide species in Yodo River estuary by the numerical ecosystem model.

    PubMed

    Hayashi, Mitsuru; Yanagi, Tetsuo

    2008-01-01

    Occurrence number of red tides in Osaka Bay in Japan is more than 20 cases every year. Diatom red tide was dominant in Osaka Bay, but the non-diatom red tide was dominant in early 1990s. Therefore, the material cycling in Yodo River estuary in Osaka Bay during August from 1991 to 2000 was analyzed by using the numerical ecosystem model and field observation data to clarify the reasons of change in red tide species. Year-to-year variation in calculated concentration ratio of diatom to non-diatom corresponds to the variation in observed ratio of red tide days of diatom to non-diatom. Limiting nutrient of primary production is phosphate over the period. Diatom dominated from 1991 to 1993, but it was difficult for non-diatom to grow due to the limitation by physical condition. Non-diatom was able to grow because of good physical and nutrient conditions from 1994 to 1996. And diatom dominated again under the good physical condition, and phosphorus supply was not enough for non-diatom to grow from 1998 to 2000. Phosphate concentration in the lower layer of Yodo River estuary was important to the variation in red tide species in the upper layer of Yodo River estuary.

  8. Changes in Work Habits of Lifeguards in Relation to Florida Red Tide

    PubMed Central

    Nierenberg, Kate; Kirner, Karen; Hoagland, Porter; Ullmann, Steven; LeBlanc, William G; Kirkpatrick, Gary; Fleming, Lora E.; Kirkpatrick, Barbara

    2010-01-01

    The marine dinoflagellate, Karenia brevis, is responsible for Florida red tides. Brevetoxins, the neurotoxins produced by K. brevis blooms, can cause fish kills, contaminate shellfish, and lead to respiratory illness in humans. Although several studies have assessed different economic impacts from Florida red tide blooms, no studies to date have considered the impact on beach lifeguard work performance. Sarasota County experiences frequent Florida red tides and staffs lifeguards at its beaches 365 days a year. This study examined lifeguard attendance records during the time periods of March 1 to September 30 in 2004 (no bloom) and March 1 to September 30 in 2005 (bloom). The lifeguard attendance data demonstrated statistically significant absenteeism during a Florida red tide bloom. The potential economic costs resulting from red tide blooms were comprised of both lifeguard absenteeism and presenteeism. Our estimate of the costs of absenteeism due to the 2005 red tide in Sarasota County is about $3,000. On average, the capitalized costs of lifeguard absenteeism in Sarasota County may be on the order of $100,000 at Sarasota County beaches alone. When surveyed, lifeguards reported not only that they experienced adverse health effects of exposure to Florida red tide but also that their attentiveness and abilities to take preventative actions decrease when they worked during a bloom, implying presenteeism effects. The costs of presenteeism, which imply increased risks to beachgoers, arguably could exceed those of absenteeism by an order of magnitude. Due to the lack of data, however, we are unable to provide credible estimates of the costs of presenteeism or the potential increased risks to bathers. PMID:20383268

  9. Changes in Work Habits of Lifeguards in Relation to Florida Red Tide.

    PubMed

    Nierenberg, Kate; Kirner, Karen; Hoagland, Porter; Ullmann, Steven; Leblanc, William G; Kirkpatrick, Gary; Fleming, Lora E; Kirkpatrick, Barbara

    2010-05-01

    The marine dinoflagellate, Karenia brevis, is responsible for Florida red tides. Brevetoxins, the neurotoxins produced by K. brevis blooms, can cause fish kills, contaminate shellfish, and lead to respiratory illness in humans. Although several studies have assessed different economic impacts from Florida red tide blooms, no studies to date have considered the impact on beach lifeguard work performance. Sarasota County experiences frequent Florida red tides and staffs lifeguards at its beaches 365 days a year. This study examined lifeguard attendance records during the time periods of March 1 to September 30 in 2004 (no bloom) and March 1 to September 30 in 2005 (bloom). The lifeguard attendance data demonstrated statistically significant absenteeism during a Florida red tide bloom. The potential economic costs resulting from red tide blooms were comprised of both lifeguard absenteeism and presenteeism. Our estimate of the costs of absenteeism due to the 2005 red tide in Sarasota County is about $3,000. On average, the capitalized costs of lifeguard absenteeism in Sarasota County may be on the order of $100,000 at Sarasota County beaches alone. When surveyed, lifeguards reported not only that they experienced adverse health effects of exposure to Florida red tide but also that their attentiveness and abilities to take preventative actions decrease when they worked during a bloom, implying presenteeism effects. The costs of presenteeism, which imply increased risks to beachgoers, arguably could exceed those of absenteeism by an order of magnitude. Due to the lack of data, however, we are unable to provide credible estimates of the costs of presenteeism or the potential increased risks to bathers.

  10. Assessing change of environmental dynamics by legislation in Japan, using red tide occurrence in Ise Bay as an indicator.

    PubMed

    Suzuki, Chika

    2016-01-30

    Tokyo Bay, Ise Bay, and the Seto Inland Sea are the total pollutant load control target areas in Japan. A significant correlation between the incidence of red tides and water quality has been observed in the Seto Inland Sea (Honjo, 1991). However, while red tides also occur in Ise Bay and Tokyo Bay, similar correlations have not been observed. Hence, it is necessary to understand what factors cause red tides to effectively manage these semi-closed systems. This study aims to investigate the relationship between the dynamics of the Red Tide Index and nitrogen regulation as well as phosphorus regulation, even in Ise Bay where, unlike Tokyo Bay, there are few observation items, by selecting a suitable objective variable. The introduction of a new technique that uses the Red Tide Index has revealed a possibility that the total pollution load control has influenced the dynamics of red tide blooms in Ise Bay.

  11. Monitoring red tide with satellite imagery and numerical models: a case study in the Arabian Gulf.

    PubMed

    Zhao, Jun; Ghedira, Hosni

    2014-02-15

    A red tide event that occurred in August 2008 in the Arabian Gulf was monitored and assessed using satellite observations and numerical models. Satellite observations revealed the bloom extent and evolution from August 2008 to August 2009. Flow patterns of the bloom patch were confirmed by results from a HYCOM model. HYCOM data and satellite-derived sea surface temperature data further suggested that the bloom could have been initiated offshore and advected onshore by bottom Ekman layer. Analysis indicated that nutrient sources supporting the bloom included upwelling, Trichodesmium, and dust deposition while other potential sources of nutrient supply should also be considered. In order to monitor and detect red tide effectively and provide insights into its initiation and maintenance mechanisms, the integration of multiple platforms is required. The case study presented here demonstrated the benefit of combing satellite observations and numerical models for studying red tide outbreaks and dynamics. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  12. Mass Stranding of Marine Birds Caused by a Surfactant-Producing Red Tide

    PubMed Central

    Jessup, David A.; Miller, Melissa A.; Ryan, John P.; Nevins, Hannah M.; Kerkering, Heather A.; Mekebri, Abdou; Crane, David B.; Johnson, Tyler A.; Kudela, Raphael M.

    2009-01-01

    In November-December 2007 a widespread seabird mortality event occurred in Monterey Bay, California, USA, coincident with a massive red tide caused by the dinoflagellate Akashiwo sanguinea. Affected birds had a slimy yellow-green material on their feathers, which were saturated with water, and they were severely hypothermic. We determined that foam containing surfactant-like proteins, derived from organic matter of the red tide, coated their feathers and neutralized natural water repellency and insulation. No evidence of exposure to petroleum or other oils or biotoxins were found. This is the first documented case of its kind, but previous similar events may have gone undetected. The frequency and amplitude of red tides have increased in Monterey Bay since 2004, suggesting that impacts on wintering marine birds may continue or increase. PMID:19234604

  13. Mass stranding of marine birds caused by a surfactant-producing red tide.

    PubMed

    Jessup, David A; Miller, Melissa A; Ryan, John P; Nevins, Hannah M; Kerkering, Heather A; Mekebri, Abdou; Crane, David B; Johnson, Tyler A; Kudela, Raphael M

    2009-01-01

    In November-December 2007 a widespread seabird mortality event occurred in Monterey Bay, California, USA, coincident with a massive red tide caused by the dinoflagellate Akashiwo sanguinea. Affected birds had a slimy yellow-green material on their feathers, which were saturated with water, and they were severely hypothermic. We determined that foam containing surfactant-like proteins, derived from organic matter of the red tide, coated their feathers and neutralized natural water repellency and insulation. No evidence of exposure to petroleum or other oils or biotoxins were found. This is the first documented case of its kind, but previous similar events may have gone undetected. The frequency and amplitude of red tides have increased in Monterey Bay since 2004, suggesting that impacts on wintering marine birds may continue or increase.

  14. [Discrimination of Red Tide algae by fluorescence spectra and principle component analysis].

    PubMed

    Su, Rong-guo; Hu, Xu-peng; Zhang, Chuan-song; Wang, Xiu-lin

    2007-07-01

    Fluorescence discrimination technology for 11 species of the Red Tide algae at genus level was constructed by principle component analysis and non-negative least squares. Rayleigh and Raman scattering peaks of 3D fluorescence spectra were eliminated by Delaunay triangulation method. According to the results of Fisher linear discrimination, the first principle component score and the second component score of 3D fluorescence spectra were chosen as discriminant feature and the feature base was established. The 11 algae species were tested, and more than 85% samples were accurately determinated, especially for Prorocentrum donghaiense, Skeletonema costatum, Gymnodinium sp., which have frequently brought Red tide in the East China Sea. More than 95% samples were right discriminated. The results showed that the genus discriminant feature of 3D fluorescence spectra of Red Tide algae given by principle component analysis could work well.

  15. Notes on a Mesodinium rubrum red tide in San Francisco Bay (California, USA)

    USGS Publications Warehouse

    Cloern, James E.; Cole, Brian E.; Hager, Stephen W.

    1994-01-01

    Discrete red patches of water were observed in South San Francisco Bay (USA) on 30 April 1993, and examination of live samples showed that this red tide was caused by surface accumulations of the pigmented ciliate Mesodinium rubrum . Vertical profiles showed strong salinity and temperature stratification in the upper 5 m, peak chlorophyll fluorescence in the upper meter, and differences in the small-scale density structure and fluorescence distribution among red patches. Events preceding this Mesodinium red tide included: (i) heavy precipitation and run-off, allowing for strong salinity stratification; (ii) a spring diatom bloom where the chlorophyll a concentration reached 50 mg m −3 ; (ii) depletions of dissolved inorganic N and Si in the photic zone; and (iv) several days of rapid warming and stabilization of the upper surface layer. These conditions may be general prerequisites for M.rubrum blooms in temperate estuaries.

  16. THE RED-TIDE DINOFLAGELLATE, ALEXANDRIUM MONILATUM, SUPPRESSES GROWTH OF MIXED NATURAL PHYTOPLANKTON

    EPA Science Inventory

    Alexandrium monilatum is a large, chain-forming, autotrophic dinoflagellate associated with red-tides and fish kills along the US Gulf of Mexico coast. When cultured inocula of A. monilatum were added to nutrient-amended seawater samples, growth rates and biomass yields of the na...

  17. GROWTH RATES, PHYSIOLOGICAL INDICATORS AND ELEMENTAL COMPOSITION OF THE RED-TIDE DINOFLAGELLATE, ALEXANDRIUM MONILATUM

    EPA Science Inventory

    Alexandrium monilatum is a thecate, autotrophic, bioluminescent and chain-forming dinoflagellate. Although it has been known to be associated with red tides and fish kills along the US Gulf of Mexico coast for almost 50 years, little basic physiological information is available f...

  18. THE RED-TIDE DINOFLAGELLATE, ALEXANDRIUM MONILATUM, SUPPRESSES GROWTH OF MIXED NATURAL PHYTOPLANKTON

    EPA Science Inventory

    Alexandrium monilatum is a large, chain-forming, autotrophic dinoflagellate associated with red-tides and fish kills along the US Gulf of Mexico coast. When cultured inocula of A. monilatum were added to nutrient-amended seawater samples, growth rates and biomass yields of the na...

  19. EVALUATION OF THE EFFECTS ON BENTHIC ORGANISMS FROM CLAY FLOCCULATION OF RED TIDE ORGANISMS

    EPA Science Inventory

    Evaluating the feasibility of controlling red tide using clay flocculation is part of an ECOHAB-funded project. One aspect for the feasibility and future application of clays is the determination of potential negative environmental impacts. The removal of toxin-containing dinofl...

  20. EVALUATION OF THE EFFECTS ON BENTHIC ORGANISMS FROM CLAY FLOCCULATION OF RED TIDE ORGANISMS

    EPA Science Inventory

    Evaluating the feasibility of controlling red tide using clay flocculation is part of an ECOHAB-funded project. One aspect for the feasibility and future application of clays is the determination of potential negative environmental impacts. The removal of toxin-containing dinofl...

  1. Bacteriological aspects of Florida red tides: A revisit and newer obervations

    NASA Astrophysics Data System (ADS)

    Buck, J. D.; Pierce, R. H.

    1989-10-01

    A brief review is presented of the literature involving the occurrence of bactera in red tides caused by the dinoflagellate Ptychodiscus brevis. Both quantitative and qualitative studies were made on outbreaks along the Florida Gulf coast in 1982 and 1987 and a bloom along the North Carolina coast in 1987. Non-bloom waters in both areas were sampled in 1988. Bacteria were also recovered from batch cultures of P. brevis. Bacterial isolates from red tide and normal waters and dinoflagellate cultures were tested for their ability to kill fish under laboratory conditions. Numbers of bacteria were always higher than reported for a 1971 outbreak but did not routinely correlate directly with P. brevis numbers. Storage of red tide water produced increased bacteria counts in some cases and decreased levels in another. Members of the genera Aeromonas, Alteromonas/Pseudomonas, and Vibrio were frequently isolated from the three blooms studied as well as from non-bloom waters; MPN of> 1100/100 ml of Vibrio alginolyticus were recorded from the latter. Dominant chromogenic bacteria, reported during previous studies, were not observed in our samples. Several bacteria killed fish experimentally including isolates from red tide and normal waters and P. brevis cultures. It was concluded that a given dinoflagellate bloom is an individual event from a bacteriological standpoint, based on quantitative and qualitative comparison of historical observations and the present study. Recent reports of tetrodotoxin production by the bacterial genera isolated above suggests a further consideration of bacteria in toxic dinoflagellate blooms.

  2. Human responses to Florida red tides: policy awareness and adherence to local fertilizer ordinances.

    PubMed

    Kirkpatrick, Barbara; Kohler, Kate; Byrne, Margaret; Fleming, Lora E; Scheller, Karen; Reich, Andrew; Hitchcock, Gary; Kirkpatrick, Gary; Ullmann, Steven; Hoagland, Porter

    2014-09-15

    To mitigate the damages of natural hazards, policy responses can be beneficial only if they are effective. Using a self-administered survey approach, this paper focuses on the adherence to local fertilizer ordinances (i.e., county or municipal rules regulating the application of fertilizer to private lawns or facilities such as golf courses) implemented in jurisdictions along the Southwest Florida coast in response to hazardous blooms of Florida red tides (Karenia brevis). These ordinances play a role in the context of evolving programs of water pollution control at federal, state, water basin, and local levels. With respect to policy effectiveness, while the strength of physical linkages is of critical importance, the extent to which humans affected are aware of and adhere to the relevant rules, is equally critical. We sought to understand the public's depth of understanding about the rationales for local fertilizer ordinances. Respondents in Sarasota, Florida, were asked about their fertilizer practices in an area that has experienced several major blooms of Florida red tides over the past two decades. A highly educated, older population of 305 residents and "snowbirds" reported relatively little knowledge about a local fertilizer ordinance, its purpose, or whether it would change the frequency, size, or duration of red tides. This finding held true even among subpopulations that were expected to have more interest in or to be more knowledgeable about harmful algal blooms. In the face of uncertain science and environmental outcomes, and with individual motivations at odds with evolving public policies, the effectiveness of local community efforts to decrease the impacts of red tides may be compromised. Targeted social-science research on human perceptions about the risks of Florida red tides and education about the rationales for potential policy responses are warranted.

  3. Temporal and spatial distribution of red tide outbreaks in the Yangtze River Estuary and adjacent waters, China.

    PubMed

    Liu, Lusan; Zhou, Juan; Zheng, Binghui; Cai, Wenqian; Lin, Kuixuan; Tang, Jingliang

    2013-07-15

    Between 1972 and 2009, evidence of red tide outbreaks in the Yangtze River Estuary and adjacent waters was collected. A geographic information system (GIS) was used to analyze the temporal and spatial distribution of these red tides, and it was subsequently used to map the distribution of these events. The results show that the following findings. (1) There were three red tide-prone areas: outside the Yangtze River Estuary and the eastern coast of Sheshan, the Huaniaoshan-Shengshan-Gouqi waters, and the Zhoushan areas and eastern coast of Zhujiajian. In these areas, red tides occurred 174 total times, 25 of which were larger than 1000 km(2) in areal extent. After 2000, the frequency of red tide outbreaks increased significantly. (2) During the months of May and June, the red tide occurrence in these areas was 51% and 20%, respectively. (3) Outbreaks of the dominant red tide plankton species Prorocentrum dong-haiense, Skeletonema costatum, Prorocentrum dantatum, and Noctiluca scientillan occurred 38, 35, 15, and 10 times, respectively, during the study interval.

  4. Feeding by the heterotrophic dinoflagellate Oxyrrhis marina on the red-tide raphidophyte Heterosigma akashiwo: a potential biological method to control red tides using mass-cultured grazers.

    PubMed

    Jeong, Hae Jin; Kim, Jae Seong; Yoo, Yeong Du; Kim, Seong Taek; Kim, Tae Hoon; Park, Myung Gil; Lee, Chang Hoon; Seong, Kyeong Ah; Kang, Nam Seon; Shim, Jae Hyung

    2003-01-01

    As part of the development of a method to control the outbreak and persistence of red tides using mass-cultured heterotrophic protist grazers, we measured the growth and ingestion rates of cultured Oxyrrhis marina (a heterotrophic dinoflagellate) on cultured Heterosigma akashiwo (a raphidophyte) in bottles in the laboratory and in mesocosms (ca. 60 liter) in nature, and those of the cultured grazer on natural populations of the red-tide organism in mesocosms set up in nature. In the bottle incubation, specific growth rates of O. marina increased rapidly with increasing concentration of cultured prey up to ca. 950 ng C ml(-1) (equivalent to 9,500 cells ml(-1)), but were saturated at higher concentrations. Maximum specific growth rate (mumax), KGR (prey concentration sustaining 0.5 mumax) and threshold prey concentration of O. marina on H. akashiwo were 1.43 d(-1), 104 ng C ml(-1), and 8.0 ng C ml(-1), respectively. Maximum ingestion and clearance rates of O. marina were 1.27 ng C grazer(-1) d(-1) and 0.3 microl grazer(-1) h(-1), respectively. Cultured O. marina grew well effectively reducing cultured and natural populations of H. akashiwo down to a very low concentration within 3 d in the mesocosms. The growth and ingestion rates of cultured O. marina on natural populations of H. akashiwo in the mesocosms were 39% and 40%, respectively, of those calculated based on the results from the bottle incubation in the laboratory, while growth and ingestion rates of cultured O. marina on cultured H. akashiwo in the mesocosms were 55% and 36%, respectively. Calculated grazing impact by O. marina on natural populations of H. akashiwo suggests that O. marina cultured on a large scale could be used for controlling red tides by H. akashiwo near aquaculture farms that are located in small ponds, lagoons, semi-enclosed bays, and large land-aqua tanks to which fresh seawater should be frequently supplied.

  5. Quantified small-scale turbulence inhibits a red tide dinoflagellate, Gonyaulax polyedra Stein

    NASA Astrophysics Data System (ADS)

    Thomas, William H.; Gibson, Carl H.

    1990-10-01

    The development of marine dinoflagellate red tides off southern California requires optimal temperature and light regimes, a source of nutrients that may be supplied by wind-induced upwelling and upmixing, and vertical migration by cells to this source. Red tides occur after the winds decrease and the water becomes highly stratified with a shallow mixed layer. This implies low turbulence levels may be an additional requirement for red tide development. Because dinoflagellates with sizes about 35 μm are much smaller than the inertial-viscous, or Kolmogorov scales L κ ≡ (ν 3/ɛ) 1/4 = (ν/γ) 1/2 of oceanic turbulence, the important flow parameters are the viscous dissipation rate per unit mass ɛ (cm 2s -3 or ergs g -1s -1), the rate-of-strain γ ≡ (ɛ/ν) 1/2 ( rad s -1) , and the stress τ ≡ μγ (dyne cm -2), where ν is the kinematic viscosity and μ is the dynamic viscosity. In the present work we have cultured the red tide dinoflagellate, Gonyaulax polyedra Stein, under conditions of known ɛ, γ and τ. Growth was inhibited at ɛ values from 0.18 to 164 cm 2 s -3 (γ from 4.4 to 132 rad s -1) but not at 0.05 ( γ = 2.2) so the threshold stress τ for growth inhibition was 0.02-0.04 dyne cm -2 (0.002-0.004 Pa). This is in the expected range for light winds at the sea surface, suggesting small-scale scale turbulence is the reason higher winds inhibit red tides. Threshold turbulence levels are related to calculated surface levels at various wind speeds and to postulated subsurface euphotic zone levels under incipient red tide conditions. Motile cells in shear-inhibited cultures lost their ability to swim forward vigorously but rather spun in place due to the loss of longitudinal (trailing) flagella, observed microscopically, without loss of girdle flagella.

  6. Red tides in the Gulf of Mexico: Where, when, and why?

    PubMed

    Walsh, J J; Jolliff, J K; Darrow, B P; Lenes, J M; Milroy, S P; Remsen, A; Dieterle, D A; Carder, K L; Chen, F R; Vargo, G A; Weisberg, R H; Fanning, K A; Muller-Karger, F E; Shinn, E; Steidinger, K A; Heil, C A; Tomas, C R; Prospero, J S; Lee, T N; Kirkpatrick, G J; Whitledge, T E; Stockwell, D A; Villareal, T A; Jochens, A E; Bontempi, P S

    2006-11-07

    [1] Independent data from the Gulf of Mexico are used to develop and test the hypothesis that the same sequence of physical and ecological events each year allows the toxic dinoflagellate Karenia brevis to become dominant. A phosphorus-rich nutrient supply initiates phytoplankton succession, once deposition events of Saharan iron-rich dust allow Trichodesmium blooms to utilize ubiquitous dissolved nitrogen gas within otherwise nitrogen-poor sea water. They and the co-occurring K. brevis are positioned within the bottom Ekman layers, as a consequence of their similar diel vertical migration patterns on the middle shelf. Upon onshore upwelling of these near-bottom seed populations to CDOM-rich surface waters of coastal regions, light-inhibition of the small red tide of ~1 ug chl l(-1) of ichthytoxic K. brevis is alleviated. Thence, dead fish serve as a supplementary nutrient source, yielding large, self-shaded red tides of ~10 ug chl l(-1). The source of phosphorus is mainly of fossil origin off west Florida, where past nutrient additions from the eutrophied Lake Okeechobee had minimal impact. In contrast, the P-sources are of mainly anthropogenic origin off Texas, since both the nutrient loadings of Mississippi River and the spatial extent of the downstream red tides have increased over the last 100 years. During the past century and particularly within the last decade, previously cryptic Karenia spp. have caused toxic red tides in similar coastal habitats of other western boundary currents off Japan, China, New Zealand, Australia, and South Africa, downstream of the Gobi, Simpson, Great Western, and Kalahari Deserts, in a global response to both desertification and eutrophication.

  7. Red tides in the Gulf of Mexico: Where, when, and why?

    PubMed Central

    Walsh, J. J.; Jolliff, J. K.; Darrow, B. P.; Lenes, J. M.; Milroy, S. P.; Remsen, A.; Dieterle, D. A.; Carder, K. L.; Chen, F. R.; Vargo, G. A.; Weisberg, R. H.; Fanning, K. A.; Muller-Karger, F. E.; Shinn, E.; Steidinger, K. A.; Heil, C. A.; Tomas, C. R.; Prospero, J. S.; Lee, T. N.; Kirkpatrick, G. J.; Whitledge, T. E.; Stockwell, D. A.; Villareal, T. A.; Jochens, A. E.; Bontempi, P. S.

    2010-01-01

    [1] Independent data from the Gulf of Mexico are used to develop and test the hypothesis that the same sequence of physical and ecological events each year allows the toxic dinoflagellate Karenia brevis to become dominant. A phosphorus-rich nutrient supply initiates phytoplankton succession, once deposition events of Saharan iron-rich dust allow Trichodesmium blooms to utilize ubiquitous dissolved nitrogen gas within otherwise nitrogen-poor sea water. They and the co-occurring K. brevis are positioned within the bottom Ekman layers, as a consequence of their similar diel vertical migration patterns on the middle shelf. Upon onshore upwelling of these near-bottom seed populations to CDOM-rich surface waters of coastal regions, light-inhibition of the small red tide of ~1 ug chl l–1 of ichthytoxic K. brevis is alleviated. Thence, dead fish serve as a supplementary nutrient source, yielding large, self-shaded red tides of ~10 ug chl l–1. The source of phosphorus is mainly of fossil origin off west Florida, where past nutrient additions from the eutrophied Lake Okeechobee had minimal impact. In contrast, the P-sources are of mainly anthropogenic origin off Texas, since both the nutrient loadings of Mississippi River and the spatial extent of the downstream red tides have increased over the last 100 years. During the past century and particularly within the last decade, previously cryptic Karenia spp. have caused toxic red tides in similar coastal habitats of other western boundary currents off Japan, China, New Zealand, Australia, and South Africa, downstream of the Gobi, Simpson, Great Western, and Kalahari Deserts, in a global response to both desertification and eutrophication. PMID:20411040

  8. Red tides in the Gulf of Mexico: Where, when, and why?

    NASA Astrophysics Data System (ADS)

    Walsh, J. J.; Jolliff, J. K.; Darrow, B. P.; Lenes, J. M.; Milroy, S. P.; Remsen, A.; Dieterle, D. A.; Carder, K. L.; Chen, F. R.; Vargo, G. A.; Weisberg, R. H.; Fanning, K. A.; Muller-Karger, F. E.; Shinn, E.; Steidinger, K. A.; Heil, C. A.; Tomas, C. R.; Prospero, J. S.; Lee, T. N.; Kirkpatrick, G. J.; Whitledge, T. E.; Stockwell, D. A.; Villareal, T. A.; Jochens, A. E.; Bontempi, P. S.

    2006-11-01

    Independent data from the Gulf of Mexico are used to develop and test the hypothesis that the same sequence of physical and ecological events each year allows the toxic dinoflagellate Karenia brevis to become dominant. A phosphorus-rich nutrient supply initiates phytoplankton succession, once deposition events of Saharan iron-rich dust allow Trichodesmium blooms to utilize ubiquitous dissolved nitrogen gas within otherwise nitrogen-poor sea water. They and the co-occurring K. brevis are positioned within the bottom Ekman layers, as a consequence of their similar diel vertical migration patterns on the middle shelf. Upon onshore upwelling of these near-bottom seed populations to CDOM-rich surface waters of coastal regions, light-inhibition of the small red tide of ˜1 ug chl l-1 of ichthytoxic K. brevis is alleviated. Thence, dead fish serve as a supplementary nutrient source, yielding large, self-shaded red tides of ˜10 ug chl l-1.The source of phosphorus is mainly of fossil origin off west Florida, where past nutrient additions from the eutrophied Lake Okeechobee had minimal impact. In contrast, the P-sources are of mainly anthropogenic origin off Texas, since both the nutrient loadings of Mississippi River and the spatial extent of the downstream red tides have increased over the last 100 years. During the past century and particularly within the last decade, previously cryptic Karenia spp. have caused toxic red tides in similar coastal habitats of other western boundary currents off Japan, China, New Zealand, Australia, and South Africa, downstream of the Gobi, Simpson, Great Western, and Kalahari Deserts, in a global response to both desertification and eutrophication.

  9. Survival and growth of Cochlodinium polykrikoides red tide after addition of yellow loess.

    PubMed

    Lee, Young Sik; Kim, Jung Dong; Lim, Weol Ae; Lee, Sam Geun

    2009-11-01

    We examined the survival rate of Cochlodinium polykrikoides after yellow loess addition and conducted culture experiments to investigate the possibility that red tides maybe caused by C. polykrikoides individuals that are precipitated when loess is added. At least 15% of the C. polykrikoides cells that precipitated to the bottom layer either by the addition of loess or no addition survived for 1 week at all growth phases, rather than disappearing immediately after precipitating. However no live cells were observed after 20 days, regardless of phase or loess addition. In the exponential phase, the number of C. polykrikoides cells increased to >2886 cells ml(-1) after loess was added. However in the stationary phase, the number of cells did not increase until 18 days. In the exponential phase, those C. polykrikoides that survived precipitation caused by scattering loess on cultures did not appear to have the ability to cause red tides again because of the short red tide periods in the field, long lag time after loess addition, and low survival rate after loess addition.

  10. A Hybrid Remote Sensing Approach for Detecting the Florida Red Tide

    NASA Astrophysics Data System (ADS)

    Carvalho, G. A.; Minnett, P. J.; Banzon, V.; Baringer, W.

    2008-12-01

    Harmful algal blooms (HABs) have caused major worldwide economic losses commonly linked with health problems for humans and wildlife. In the Eastern Gulf of Mexico the toxic marine dinoflagellate Karenia brevis is responsible for nearly annual, massive red tides causing fish kills, shellfish poisoning, and acute respiratory irritation in humans: the so-called Florida Red Tide. Near real-time satellite measurements could be an effective method for identifying HABs. The use of space-borne data would be a highly desired, low-cost technique offering the remote and accurate detection of K. brevis blooms over the West Florida Shelf, bringing tremendous societal benefits to the general public, scientific community, resource managers and medical health practitioners. An extensive in situ database provided by the Florida Fish and Wildlife Conservation Commission's Research Institute was used to examine the long-term accuracy of two satellite- based algorithms at detecting the Florida Red Tide. Using MODIS data from 2002 to 2006, the two algorithms are optimized and their accuracy assessed. It has been found that the sequential application of the algorithms results in improved predictability characteristics, correctly identifying ~80% of the cases (for both sensitivity and specificity, as well as overall accuracy), and exhibiting strong positive (70%) and negative (86%) predictive values.

  11. [Fluorescence characterization of dissolved organic matter in the East China Sea after diatom red tide dispersion].

    PubMed

    Zhuo, Peng-ji; Zhao, Wei-hong

    2009-05-01

    Fluorescence excitation-emission spectroscopy (EEMS) was employed to analyze the 3-dimensional fluorescence of dissolved organic matter in the East China Sea after diatom red tide dispersion. The relationships between fluorescence peak intensity, and salinity and chlorophyll-a were discussed. The centers of protein-like fluorescence peaks dispersed at Exmax/Exmax = 270-280/290-315 nm (Peak B), 220-230/290-305 nm (Peak D), 230-240/335-350 nm (Peak S) and 280/320 nm (Peak T). Two humic-like peaks appeared at 255-270/435-480 nm (Peak A)and 330-350/420-480 nm (Peak C). High tyrosine-like intensity was observed in diatom red tide dispersion area, and tryptophan-like fluorescence was also found which was lower. High FIB/FIS showed that diatom red tide produced much tyrosine-like matter during dispersion. Peaks S, A and C had positive correlation with one another, and their distributions were similar, which decreased with distance increasing away from the shore. Good negative correlations between peaks S, A and C and salinity suggested that Jiangsu-Zhejiang coastal water was the same source of them. Correlations between fluorescence peak intensity and chlorophyll-a were not remarkable enough to clear the relationship between fluorescence and living algal matter. It was supposed that the living algal matter contributed little to the fluorescence intensity of algal dispersion seawater.

  12. Harmful algal toxins of the Florida red tide (Karenia brevis): natural chemical stressors in South Florida coastal ecosystems.

    PubMed

    Pierce, R H; Henry, M S

    2008-10-01

    The Florida red tide is a descriptive name for high concentrations of the harmful marine alga, Karenia brevis. Although most prevalent along the south-west Florida coast, periodic blooms have occurred throughout the entire US and Mexico Gulf coasts and the Atlantic coast to North Carolina. This dinoflagellate produces a suite of polyether neurotoxins, called brevetoxins, that cause severe impacts to natural resources, as well as public health. These naturally produced biotoxins may represent one of the most common chemical stressors impacting South Florida coastal and marine ecosystems. Impacts include massive fish kills, marine mammal, sea turtle and sea bird mortalities, benthic community die-off and public health effects from shellfish contamination and inhalation of air-borne toxins. The primary mode of action is binding to voltage-gated sodium channels causing depolarization of nerve cells, thus interfering with nerve transmission. Other effects include immune depression, bronchial constriction and haemolysis. Parent algal toxins are synthesized within the unicellular organism, others are produced as metabolic products. Recent studies into the composition of brevetoxins in cells, water, air and organisms have shown PbTx-2 to be the primary intracellular brevetoxin that is converted over time to PbTx-3 when the cells are ruptured, releasing extracellular brevetoxins into the environment. Brevetoxins become aerosolized by bubble-mediated transport of extracellular toxins, the composition of which varies depending on the composition in the source water. Bivalved molluscs rapidly accumulate brevetoxins as they filter feed on K. brevis cells. However, the parent algal toxins are rapidly metabolized to other compounds, some of which are responsible for neurotoxic shellfish poisoning (NSP). These results provide new insight into the distribution, persistence and impacts of red tide toxins to south-west Florida ecosystems.

  13. Harmful algal toxins of the Florida red tide (Karenia brevis): natural chemical stressors in South Florida coastal ecosystems

    PubMed Central

    Henry, M. S.

    2009-01-01

    The Florida red tide is a descriptive name for high concentrations of the harmful marine alga, Karenia brevis. Although most prevalent along the south-west Florida coast, periodic blooms have occurred throughout the entire US and Mexico Gulf coasts and the Atlantic coast to North Carolina. This dinoflagellate produces a suite of polyether neurotoxins, called brevetoxins, that cause severe impacts to natural resources, as well as public health. These naturally produced biotoxins may represent one of the most common chemical stressors impacting South Florida coastal and marine ecosystems. Impacts include massive fish kills, marine mammal, sea turtle and sea bird mortalities, benthic community die-off and public health effects from shellfish contamination and inhalation of air-borne toxins. The primary mode of action is binding to voltage-gated sodium channels causing depolarization of nerve cells, thus interfering with nerve transmission. Other effects include immune depression, bronchial constriction and haemolysis. Parent algal toxins are synthesized within the unicellular organism, others are produced as metabolic products. Recent studies into the composition of brevetoxins in cells, water, air and organisms have shown PbTx-2 to be the primary intracellular brevetoxin that is converted over time to PbTx-3 when the cells are ruptured, releasing extracellular brevetoxins into the environment. Brevetoxins become aerosolized by bubble-mediated transport of extracellular toxins, the composition of which varies depending on the composition in the source water. Bivalved molluscs rapidly accumulate brevetoxins as they filter feed on K. brevis cells. However, the parent algal toxins are rapidly metabolized to other compounds, some of which are responsible for neurotoxic shellfish poisoning (NSP). These results provide new insight into the distribution, persistence and impacts of red tide toxins to south-west Florida ecosystems. PMID:18758951

  14. Isolation and purification of antialgal compounds from the red alga Gracilaria lemaneiformis for activity against common harmful red tide microalgae.

    PubMed

    Sun, Ying-Ying; Meng, Kun; Su, Zhen-Xia; Guo, Gan-Lin; Pu, Yin-Fang; Wang, Chang-Hai

    2017-02-01

    Seven antialgal compounds (1-7) were successfully isolated from the red alga Gracilaria lemaneiformis through a combination of silica gel column chromatography and repeated preparative thin-layer chromatography. On the basis of the spectral data, the compounds were identified as gossonorol (1), 7,10-epoxy-ar-bisabol-11-ol (2), glycerol monopalmitate (3), stigmasterol (4), 15-hydroxymethyl-2, 6, 10, 18, 22, 26, 30-heptamethyl-14-methylene-17-hentriacontene (5), 4-hydroxyphenethyl alcohol (6), and margaric acid (7). These seven compounds were isolated from G. lemaneiformis for the first time, while the compounds 4, 6, and 7 were isolated from marine macroalgae for the first time. Furthermore, a quantitative relationship between the inhibition of algal growth and the concentration of each antialgal compound was determined and important parameters for future practical HAB control, e.g., EC50-96h, were also obtained. The results indicated that isolated compounds 1-7 possess selective antialgal activity against the growth of several red tide microalgae (including Amphidinium carterae, Heterosigma akashiwo, Karenia mikimitoi, Phaeocystis globsa, Prorocentrum donghaiense, and Skeletonema costatum). Their antialgal activity against test red tide microalgae has not been previously reported. Furthermore, the EC50-96h of one or more of the compounds towards the tested red microalgae was not only significantly less than 10 μg/mL but also was smaller than that of the characteristic antialgal agent potassium dichromate. The study demonstrates that compounds 1-7 possess significant application potential as antialgal agents against several harmful red tide microalgae.

  15. Factors affecting outbreaks of high-density Cochlodinium polykrikoides red tides in the coastal seawaters around Yeosu and Tongyeong, Korea.

    PubMed

    Lee, Young Sik

    2006-10-01

    Red tides caused by the dinoflagellate Cochlodinium polykrikoides occur annually in coastal waters of Korea, causing significant damage. A distinguishing characteristic of C. polykrikoides red tides is that they develop and persist in the open sea, where the water is comparatively clean with little contamination from the shore. We examined the causes of and key nutrients involved in high-density C. polykrikoides red tide outbreaks in the coastal seawaters around Yeosu and Tongyeong, Korea. High-density C. polykrikoides red tides occur in the coastal areas of Geomo Island, where freshwater flows into the sea after heavy rainfall events. Red tides are widespread in years when rainfall is heavy. The maximum concentration of C. polykrikoides and the duration of the red tides increase with increasing rainfall. Adding nitrogen and Seomjin River water to cultures of C. polykrikoides also increases biomass production and cell density of C. polykrikoides remarkably increased after heavy rainfall events. The occurrence of high concentrations of C. polykrikoides along the shores of Yeosu and Tongyeong seems to result from rainfall-initiated inflows of high concentrations of nitrate secondarily, after a conducive physical and chemical open-water environment has been established for C. polykrikoides to spread initially.

  16. Viral Lysogeny as a Potential Mechanism for Termination of a Red Tide Event

    NASA Astrophysics Data System (ADS)

    Martinez, S. B.; Kudela, R. M.; Broughton, J.

    2014-12-01

    Red tides are high-biomass blooms in the coastal ocean typically caused by dinoflagellates. While some red tides are harmful (via toxin production, high biomass, and oxygen depletion during decay), they also provide an important source of energy and carbon for other trophic levels. Red tides are often ephemeral, so while it is easy to identify one, what causes these events to terminate can vary. It has been hypothesized that viral lysis and parasitic infection may be important vectors of termination for these blooms. This study sought to compare the decay of one such bloom in Monterey Bay, California to in situ and mesocosm studies where bloom termination was due to viral lysis. To achieve this goal we used MODIS ocean color Level 2 data with spatial resolution of 1km; we identified and averaged RRS from 9 pixels within the northern "red tide incubator" region of Monterey Bay where a dinoflagellate bloom was identified. We applied the quasi-analytical algorithm (QAA) to derive the backscatter coefficient (bbp(λ)), absorption due to chlorophyll (aChl), and the gelbstoff absorption coefficient (ag). Separate equations were used to find the volume scattering function (β(ψ,λ) where ψ =140°) and the particle size distribution hyperbolic slope (ξ). A MODIS satellite time series of five days (during an eight-day period) confirmed optical changes similar to documented shifts in laboratory-controlled experiments examining viral lysis. As predicted from previous results, the decrease in chlorophyll - essentially the deterioration of the algal bloom - resulted in the anticipated decrease in bbp(λ) and VSF values as well as an increase in ξ. aChl and ag were also compared to the Morel 2009 band algorithm for Colored Dissolved Organic Matter (CDOM) and the OC3 band algorithm for chlorophyll concentration. Results indicate that the QAA retrievals cannot be statistically distinguished (using a paired t-test) from the Morel and OC3 band algorithms. Analyzing more bloom

  17. Physical-biological coupling induced aggregation mechanism for the formation of high biomass red tides in low nutrient waters.

    PubMed

    Lai, Zhigang; Yin, Kedong

    2014-01-01

    Port Shelter is a semi-enclosed bay in northeast Hong Kong where high biomass red tides are observed to occur frequently in narrow bands along the local bathymetric isobars. Previous study showed that nutrients in the Bay are not high enough to support high biomass red tides. The hypothesis is that physical aggregation and vertical migration of dinoflagellates appear to be the driving mechanism to promote the formation of red tides in this area. To test this hypothesis, we used a high-resolution estuarine circulation model to simulate the near-shore water dynamics based on in situ measured temperature/salinity profiles, winds and tidal constitutes taken from a well-validated regional tidal model. The model results demonstrated that water convergence occurs in a narrow band along the west shore of Port Shelter under a combined effect of stratified tidal current and easterly or northeasterly wind. Using particles as dinoflagellate cells and giving diel vertical migration, the model results showed that the particles aggregate along the convergent zone. By tracking particles in the model predicted current field, we estimated that the physical-biological coupled processes induced aggregation of the particles could cause 20-45 times enhanced cell density in the convergent zone. This indicated that a high cell density red tide under these processes could be initialized without very high nutrients concentrations. This may explain why Port Shelter, a nutrient-poor Bay, is the hot spot for high biomass red tides in Hong Kong in the past 25 years. Our study explains why red tide occurrences are episodic events and shows the importance of taking the physical-biological aggregation mechanism into consideration in the projection of red tides for coastal management.

  18. Automatic cell object extraction of red tide algae in microscopic images

    NASA Astrophysics Data System (ADS)

    Yu, Kun; Ji, Guangrong; Zheng, Haiyong

    2016-05-01

    Extracting the cell objects of red tide algae is the most important step in the construction of an automatic microscopic image recognition system for harmful algal blooms. This paper describes a set of composite methods for the automatic segmentation of cells of red tide algae from microscopic images. Depending on the existence of setae, we classify the common marine red tide algae into non-setae algae species and Chaetoceros, and design segmentation strategies for these two categories according to their morphological characteristics. In view of the varied forms and fuzzy edges of non-setae algae, we propose a new multi-scale detection algorithm for algal cell regions based on border- correlation, and further combine this with morphological operations and an improved GrabCut algorithm to segment single-cell and multicell objects. In this process, similarity detection is introduced to eliminate the pseudo cellular regions. For Chaetoceros, owing to the weak grayscale information of their setae and the low contrast between the setae and background, we propose a cell extraction method based on a gray surface orientation angle model. This method constructs a gray surface vector model, and executes the gray mapping of the orientation angles. The obtained gray values are then reconstructed and linearly stretched. Finally, appropriate morphological processing is conducted to preserve the orientation information and tiny features of the setae. Experimental results demonstrate that the proposed methods can eff ectively remove noise and accurately extract both categories of algae cell objects possessing a complete shape, regular contour, and clear edge. Compared with other advanced segmentation techniques, our methods are more robust when considering images with different appearances and achieve more satisfactory segmentation eff ects.

  19. Automatic cell object extraction of red tide algae in microscopic images

    NASA Astrophysics Data System (ADS)

    Yu, Kun; Ji, Guangrong; Zheng, Haiyong

    2017-03-01

    Extracting the cell objects of red tide algae is the most important step in the construction of an automatic microscopic image recognition system for harmful algal blooms. This paper describes a set of composite methods for the automatic segmentation of cells of red tide algae from microscopic images. Depending on the existence of setae, we classify the common marine red tide algae into non-setae algae species and Chaetoceros, and design segmentation strategies for these two categories according to their morphological characteristics. In view of the varied forms and fuzzy edges of non-setae algae, we propose a new multi-scale detection algorithm for algal cell regions based on border- correlation, and further combine this with morphological operations and an improved GrabCut algorithm to segment single-cell and multicell objects. In this process, similarity detection is introduced to eliminate the pseudo cellular regions. For Chaetoceros, owing to the weak grayscale information of their setae and the low contrast between the setae and background, we propose a cell extraction method based on a gray surface orientation angle model. This method constructs a gray surface vector model, and executes the gray mapping of the orientation angles. The obtained gray values are then reconstructed and linearly stretched. Finally, appropriate morphological processing is conducted to preserve the orientation information and tiny features of the setae. Experimental results demonstrate that the proposed methods can effectively remove noise and accurately extract both categories of algae cell objects possessing a complete shape, regular contour, and clear edge. Compared with other advanced segmentation techniques, our methods are more robust when considering images with different appearances and achieve more satisfactory segmentation effects.

  20. [Povidone-iodine and isothiozolone for removing red tide algae Phaeoecystis globosa].

    PubMed

    Hong, Aihua; Yin, Pinghe; Zhao, Ling; Huang, Yunfeng; Qi, Yuzao; Xie, Longchu

    2003-07-01

    Studies on the removal and control of red tide algae Phaeoecystis globosa by povidone-iodine and isothiozolone algaecide showed that Phaeoecystis globosa could be killed and controlled by povidone-iodine and isothiozolone. The effective concentration of povidone-iodine was 30 mg.L-1, and that of isothiozolone was 0.30 mg.L-1. Using povidone-iodine and isothiozolone together could improve the effect, and the ideal composite ratio of povidone-iodine and isothiozolone was 1.0:0.15.

  1. [Applications of three-dimensional fluorescence spectrum of dissolved organic matter to identification of red tide algae].

    PubMed

    Lü, Gui-Cai; Zhao, Wei-Hong; Wang, Jiang-Tao

    2011-01-01

    The identification techniques for 10 species of red tide algae often found in the coastal areas of China were developed by combining the three-dimensional fluorescence spectra of fluorescence dissolved organic matter (FDOM) from the cultured red tide algae with principal component analysis. Based on the results of principal component analysis, the first principal component loading spectrum of three-dimensional fluorescence spectrum was chosen as the identification characteristic spectrum for red tide algae, and the phytoplankton fluorescence characteristic spectrum band was established. Then the 10 algae species were tested using Bayesian discriminant analysis with a correct identification rate of more than 92% for Pyrrophyta on the level of species, and that of more than 75% for Bacillariophyta on the level of genus in which the correct identification rates were more than 90% for the phaeodactylum and chaetoceros. The results showed that the identification techniques for 10 species of red tide algae based on the three-dimensional fluorescence spectra of FDOM from the cultured red tide algae and principal component analysis could work well.

  2. Light spectrum regulates cell accumulation during daytime in the raphidophyte Chattonella antiqua causing noxious red tides.

    PubMed

    Shikata, Tomoyuki; Matsunaga, Shigeru; Kuwahara, Yusuke; Iwahori, Sho; Nishiyama, Yoshitaka

    2016-07-01

    Most marine raphidophyte species cause noxious red tides in temperate coastal areas around the world. It is known that swimming abilities enable raphidophytes to accumulation of cells and to actively acquire light at surface layers and nutrients over a wide depth range. However, it remains unclear how the swimming behavior is affected by environmental conditions, especially light condition. In the present study, we observed the accumulation of the harmful red-tide raphidophyte Chattonella antiqua under various light conditions during the daytime in the laboratory. When exposed to ultraviolet-A/blue light (320-480nm) or red light (640-680nm) from above, cells moved downward. In the case of blue light (455nm), cells started to swim downward after 5-15min of irradiation at a photon flux density≥10μmolm(-2)s(-1). When exposed to monochromatic lights (400-680nm) from the side, cells moved away from the blue light source and then descended, but just moved downward under red light. However, mixing of green/orange light (520-630nm) diminished the effects of blue light. When exposed to a mixture of 30μmolm(-2)s(-1) of blue light (440nm) and ≥6μmolm(-2)s(-1) of yellow light (560nm) from above, cells did not move downward. These results indicate that blue light induces negative phototaxis and ultraviolet-A/blue and red lights induce descending, and green/orange light cancels out their effects in C. antiqua.

  3. Blue and red light-induced germination of resting spores in the red-tide diatom Leptocylindrus danicus.

    PubMed

    Shikata, Tomoyuki; Iseki, Mineo; Matsunaga, Shigeru; Higashi, Sho-ichi; Kamei, Yasuhiro; Watanabe, Masakatsu

    2011-01-01

    Photophysiological and pharmacological approaches were used to examine light-induced germination of resting spores in the red-tide diatom Leptocylindrus danicus. The equal-quantum action spectrum for photogermination had peaks at about 440 nm (blue light) and 680 nm (red light), which matched the absorption spectrum of the resting spore chloroplast, as well as photosynthetic action spectra reported for other diatoms. DCMU, an inhibitor of photosynthetic electron flow near photosystem II, completely blocked photogermination. These results suggest that the photosynthetic system is involved in the photoreception process of light-induced germination. Results of pharmacological studies of the downstream signal transduction pathway suggested that Ca(2+) influx is the closest downstream neighbor, followed by steps involving calmodulin, nitric oxide synthase, guanylyl cyclase, protein-tyrosine-phosphatase, protein kinase C and actin polymerization and translation.

  4. Interactions between the pathogenic bacterium Vibrio parahaemolyticus and red-tide dinoflagellates

    NASA Astrophysics Data System (ADS)

    Seong, Kyeong Ah; Jeong, Hae Jin

    2011-06-01

    Vibrio parahaemolyticus is a common pathogenic bacterium in marine and estuarine waters. To investigate interactions between V. parahaemolyticus and co-occurring redtide dinoflagellates, we monitored the daily abundance of 5 common red tide dinoflagellates in laboratory culture; Amphidinium carterae, Cochlodinium ploykrikoides, Gymnodinium impudicum, Prorocentrum micans, and P. minimum. Additionally, we measured the ingestion rate of each dinoflagellate on V. parahaemolyticus as a function of prey concentration. Each of the dinoflagellates responded differently to the abundance of V. parahaemolyticus. The abundances of A. carterae and P. micans were not lowered by V. parahaemolyticus, whereas that of C. polykrikodes was lowered considerably. The harmful effect depended on bacterial concentration and incubation time. Most C. polykrikoides cells died after 1 hour incubation when the V. parahaemolyticus concentration was 1.4×107 cells ml-1, while cells died within 2 days of incubation when the bacterial concentration was 1.5×106 cells ml-1. With increasing V. parahaemolyticus concentration, ingestion rates of P. micans, P. minimum, and A. carterae on the prey increased, whereas that on C. polykrikoides decreased. The maximum or highest ingestion rates of P. micans, P. minimum, and A. carterae on V. parahaemolyticus were 55, 5, and 2 cells alga-1 h-1, respectively. The results of the present study suggest that V. parahaemolyticus can be both the killer and prey for some red tide dinoflagellates.

  5. Observing Red Tide Algal Blooms From Satellite Ocean Color Imagery: West Florida Shelf

    NASA Astrophysics Data System (ADS)

    Krueger, E. T.; Jose, F.

    2016-12-01

    Harmful algal blooms (HABs) from Karenia brevis occur along the west Florida shelf (WFS) almost every year, producing a brevetoxin that is harmful to birds, fish, marine mammals, shellfish, and humans. These HABs are commonly known as "red tide" from the reddish discoloration in the water, but color can vary from yellow to deep brown depending on other parameters. Ocean color data is a viable tool for monitoring the outbreak and persistence of these ecological phenomena. Also, the spatial extend of this outbreak could be evaluated effectively from satellite imagery. Chlorophyll (Chl) and sea surface temperature (SST) data from four satellites during the period from 2010 to 2013 were analyzed, and compared the monthly composite data with in situ observation on K. brevis cell counts collected by the Florida Fish and Wildlife Conservation Commission (FWC). Remote sensing data were extracted from the NASA Ocean Color data servers and were processed using WimSoft, a Windows-based remote sensing data analysis program. Based on the comparison of data from 26 transects from the WFS, which were extended from nearshore to 400 km offshore, highest Chl concentrations were observed in the sector from St. Petersburg to Sanibel Island. FWC data also showed that highest K. brevis cell counts were concentrated in this region during the 2011 to 2012 period. Additionally, a high Chl concentration was observed for the Big Bend region, particularly during the spring and early summer. The inter-annual variability of Chl, SST, and red tide occurrence are also discussed in this study.

  6. The red tide toxin, brevetoxin, induces embryo toxicity and developmental abnormalities.

    PubMed Central

    Kimm-Brinson, K L; Ramsdell, J S

    2001-01-01

    Brevetoxins are lipophilic polyether toxins produced by the red tide dinoflagellate Gymnodinium breve, and their neurotoxic effects on adult animals have been documented. In this study, we characterized adverse developmental effects of brevetoxin-1 (PbTx-1) using an exposure paradigm that parallels the maternal oocyte transfer of toxin. Medaka fish (Oryzias latipes) embryos were exposed to PbTx-1 via microinjection of toxin reconstituted in a triolein oil droplet. Embryos microinjected with doses of 0.1-8.0 ng/egg (ppm) of brevetoxin-1 exhibited pronounced muscular activity (hyperkinesis) after embryonic day 4. Upon hatching, morphologic abnormalities were commonly found in embryos at the following lowest adverse effect levels: 1.0-3.0 ppm, lateral curvature of the spinal column; 3.1-3.4 ppm, herniation of brain meninges through defects in the skull; and 3.4-4.0 ppm, malpositioned eye. Hatching abnormalities were also commonly observed at brevetoxin doses of 2.0 ppm and higher with head-first, as opposed to the normal tail-first, hatching, and doses > 4.1 ng/egg produced embryos that developed but failed to hatch. Given the similarity of developmental processes found between higher and lower vertebrates, teratogenic effects of brevetoxins have the potential to occur among different phylogenetic classes. The observation of developmental abnormalities after PbTx-1 exposure identifies a new spectrum of adverse effects that may be expected to occur following exposure to G. breve red tide events. PMID:11335186

  7. [Distributions of COD and petroleum hydrocarbons and their relationships with occurrence of red tide in East China Sea].

    PubMed

    Zhang, Chuansong; Wang, Xiulin; Shi, Xiaoyong; Han, Xiurong; Sun, Xia; Zhu, Chenjian; Lu, Rong

    2003-07-01

    Based on the data of COD and petroleum hydrocarbons collected in the cruise from April 25 to May 2, 2002 in intensive red tide occurrence areas in East China Sea, the distribution of COD, and petroleum hydrocarbons and the eutrophication index(EI) were analyzed. The results showed that the EI and COD value were both high in coastal water, and decreased gradually away from shore. After the preliminary study on the relationships between correlative factors and occurrence of red tide, it was found that high EI and COD were necessary. There would be great chances for the red tide to break out under conditions that the EI was between 2.5 and 15 and COD concentration was between 0.8 to 1.4 mg.L-1 in seawater, along with the favorable temperature and salinity.

  8. The red tide event in El Salvador, August 2001-January 2002.

    PubMed

    Enrique Barraza, José; Armero-Guardado, Julio; Valencia de Toledo, Zobeyda Marisol

    2004-09-01

    A red tide event occurred in El Salvador from August 2001 to January 2002. National health authorities usually measured toxin levels in Ostrea iridescens, however other species were analyzed during this microalgae bloom: Anadara similis, Anadara tuberculosa and Modiolus sp. El Salvador authorities consider 400 mouse units/100 g the highest value that is safe for human health. During this period toxin levels in 0. iridescens and Modiolus sp. increased from values under 400 to 3977 and 15,468 mouse units/100 g, respectively. Persistent and higher levels were recorded in oyster and mussel banks on the west part of the country. The Ministry of Health and Social Assistance treated 41 slight to moderate intoxications associated to bivalve mollusks consumption.

  9. Utilizing the algicidal activity of aminoclay as a practical treatment for toxic red tides

    PubMed Central

    Lee, Young-Chul; Jin, EonSeon; Jung, Seung Won; Kim, Yeon-Mi; Chang, Kwang Suk; Yang, Ji-Won; Kim, Si-Wouk; Kim, Young-Ok; Shin, Hyun-Jae

    2013-01-01

    In recent decades, harmful algal blooms (HABs) – commonly known as red tides – have increasingly impacted human health, caused significant economic losses to fisheries and damaged coastal environments and ecosystems. Here, we demonstrate a method to control and suppress HABs through selective algal lysis. The approach harnesses the algicidal effects of aminoclays, which are comprised of a high density of primary amine groups covalently bonded by metal cation backbones. Positively charged colloidals of aminoclays induce cell lysis in HABs within several minutes exposure but have negligible impact on non-harmful phytoplankton, zooplankton and farmed fish. This selective lysis is due to the ammonium characteristics of the aminoclay and the electrostatic attraction between the clay nanoparticles and the algal cells. In contrast, yellow loess clay, a recognized treatment for HABs, causes algal flocs with little cell lysis. Thus, the aminoclay loading can be effective for the mitigation of HABs. PMID:23416422

  10. Utilizing the algicidal activity of aminoclay as a practical treatment for toxic red tides.

    PubMed

    Lee, Young-Chul; Jin, EonSeon; Jung, Seung Won; Kim, Yeon-Mi; Chang, Kwang Suk; Yang, Ji-Won; Kim, Si-Wouk; Kim, Young-Ok; Shin, Hyun-Jae

    2013-01-01

    In recent decades, harmful algal blooms (HABs) - commonly known as red tides - have increasingly impacted human health, caused significant economic losses to fisheries and damaged coastal environments and ecosystems. Here, we demonstrate a method to control and suppress HABs through selective algal lysis. The approach harnesses the algicidal effects of aminoclays, which are comprised of a high density of primary amine groups covalently bonded by metal cation backbones. Positively charged colloidals of aminoclays induce cell lysis in HABs within several minutes exposure but have negligible impact on non-harmful phytoplankton, zooplankton and farmed fish. This selective lysis is due to the ammonium characteristics of the aminoclay and the electrostatic attraction between the clay nanoparticles and the algal cells. In contrast, yellow loess clay, a recognized treatment for HABs, causes algal flocs with little cell lysis. Thus, the aminoclay loading can be effective for the mitigation of HABs.

  11. Identification of the toxic compounds produced by Sargassum thunbergii to red tide microalgae

    NASA Astrophysics Data System (ADS)

    Wang, Renjun; Wang, You; Tang, Xuexi

    2012-09-01

    The inhibitory effects of methanol extracts from the tissues of three macroalgal species on the growths of three marine red tide microalgae were assessed under laboratory conditions. Extracts of Sargassum thunbergii (Mertens ex Roth) Kuntz tissue had stronger inhibitory effects than those of either Sargassum pallidum (Turner) C. Agardh or Sargassum kjellmanianum Yendo on the growths of Heterosigma akashiwo (Hada) Hada, Skeletonema costatum (Grev.) Grev, and Prorocentrum micans Ehrenberg. Methanol extracts of S. thunbergii were further divided into petroleum ether, ethyl acetate, butanol, and distilled water phases by liquid-liquid fractionation. The petroleum ether and ethyl acetate fractions had strong algicidal effects on the microalgae. Gas chromatography-mass spectrometry analyses of these two phases identified nine fatty acids, most of which were unsaturated fatty acids. In addition, pure compounds of four of the nine unsaturated fatty acids had effective concentrations below 5 mg/L. Therefore, unsaturated fatty acids are a component of the allelochemicals in S. thunbergii tissue.

  12. Space station image captures a red tide ciliate bloom at high spectral and spatial resolution

    PubMed Central

    Dierssen, Heidi; McManus, George B.; Chlus, Adam; Qiu, Dajun; Gao, Bo-Cai; Lin, Senjie

    2015-01-01

    Mesodinium rubrum is a globally distributed nontoxic ciliate that is known to produce intense red-colored blooms using enslaved chloroplasts from its algal prey. Although frequent enough to have been observed by Darwin, blooms of M. rubrum are notoriously difficult to quantify because M. rubrum can aggregate into massive clouds of rusty-red water in a very short time due to its high growth rates and rapid swimming behavior and can disaggregate just as quickly by vertical or horizontal dispersion. A September 2012 hyperspectral image from the Hyperspectral Imager for the Coastal Ocean sensor aboard the International Space Station captured a dense red tide of M. rubrum (106 cells per liter) in surface waters of western Long Island Sound. Genetic data confirmed the identity of the chloroplast as a cryptophyte that was actively photosynthesizing. Microscopy indicated extremely high abundance of its yellow fluorescing signature pigment phycoerythrin. Spectral absorption and fluorescence features were related to ancillary photosynthetic pigments unique to this organism that cannot be observed with traditional satellites. Cell abundance was estimated at a resolution of 100 m using an algorithm based on the distinctive yellow fluorescence of phycoerythrin. Future development of hyperspectral satellites will allow for better enumeration of bloom-forming coastal plankton, the associated physical mechanisms, and contributions to marine productivity. PMID:26627232

  13. Space station image captures a red tide ciliate bloom at high spectral and spatial resolution.

    PubMed

    Dierssen, Heidi; McManus, George B; Chlus, Adam; Qiu, Dajun; Gao, Bo-Cai; Lin, Senjie

    2015-12-01

    Mesodinium rubrum is a globally distributed nontoxic ciliate that is known to produce intense red-colored blooms using enslaved chloroplasts from its algal prey. Although frequent enough to have been observed by Darwin, blooms of M. rubrum are notoriously difficult to quantify because M. rubrum can aggregate into massive clouds of rusty-red water in a very short time due to its high growth rates and rapid swimming behavior and can disaggregate just as quickly by vertical or horizontal dispersion. A September 2012 hyperspectral image from the Hyperspectral Imager for the Coastal Ocean sensor aboard the International Space Station captured a dense red tide of M. rubrum (10(6) cells per liter) in surface waters of western Long Island Sound. Genetic data confirmed the identity of the chloroplast as a cryptophyte that was actively photosynthesizing. Microscopy indicated extremely high abundance of its yellow fluorescing signature pigment phycoerythrin. Spectral absorption and fluorescence features were related to ancillary photosynthetic pigments unique to this organism that cannot be observed with traditional satellites. Cell abundance was estimated at a resolution of 100 m using an algorithm based on the distinctive yellow fluorescence of phycoerythrin. Future development of hyperspectral satellites will allow for better enumeration of bloom-forming coastal plankton, the associated physical mechanisms, and contributions to marine productivity.

  14. PHYLOGENETIC RELATIONSHIP OF THE RED TIDE DINOFLAGELLATE GYMNODINIUM BREVE TO OTHER MEMBERS OF THE GENERA GYMNODINIUM AND GYRODINIUM

    EPA Science Inventory

    Phylogenetic relationships between the red-tide dinoflagellate Gymnodinium breve and other members of the genera Gymnodinium and Gyrodinium have not been studied at the molecular level. G. breve is most noted for its production of brevetoxin, which has been linked to extensive f...

  15. PHYLOGENETIC RELATIONSHIP OF THE RED TIDE DINOFLAGELLATE GYMNODINIUM BREVE TO OTHER MEMBERS OF THE GENERA GYMNODINIUM AND GYRODINIUM

    EPA Science Inventory

    Phylogenetic relationships between the red-tide dinoflagellate Gymnodinium breve and other members of the genera Gymnodinium and Gyrodinium have not been studied at the molecular level. G. breve is most noted for its production of brevetoxin, which has been linked to extensive f...

  16. Phytoplankton and bacterial community structures and their interaction during red-tide phenomena

    NASA Astrophysics Data System (ADS)

    Ismail, Mona Mohamed; Ibrahim, Hassan Abd Allah

    2017-07-01

    Phytoplankton and bacteria diversity were studied before, during and after red tide phenomena during spring season 2015 in the Eastern Harbour (E.H.) of Alexandria, Egypt. Fifty five species of phytoplankton were identified and represented different distinct classes "Bacillariophyceae; Dinophyceae, Chlorophyceae, Cyanophyceae and Eugelenophyceae". Also, Diatom formed the most dominant group. The average number of the phytoplankton density varied from 4.8 × 104 to 1.1 × 106 cell l-1 during the study period and Skeletonema costatum was the agent causing the red tide. The existence percentages of bacteria ranged from 2.6 to 17.9% on all media tested. The bacterial isolates on the nutrient agar medium represented the highest existence with a total percentage of 43.6%, followed by MSA medium (25.7%), while the lowest percentage was for the AA medium at 7.8%. However, twelve isolates were selected as representative for bacterial community during study interval. Based on the morphological, biochemical, physiological and enzymatic characteristics, the bacterial strains were described. Depending on the 16S rDNA gene sequence, three common antagonists were aligned as: Vibrio toranzoniae strain Vb 10.8, Ruegeria pelagia strain NBRC 102038 and Psychrobacter adeliensis strain DSM 15333. The interaction between these bacteria and S. costatum was studied. The growth of S. costatum was significantly lower whenever each bacterium was present as compared to axenic culture. More specifically, 30% (v/v) of the all tested bacteria showed the strongest algicidal activities, as all S. costatum cells were killed after two days. 10% of R. pelagia and P. adeliensis also showed significant algicidal activities within six days.

  17. Integrated Use Of MERIS And Other EO Data For Water Quality And Red Tide Monitoring Along United Arab Emirates Coasts

    NASA Astrophysics Data System (ADS)

    Ceriola, G.; Avgikou, V.; Manunta, P.

    2013-12-01

    Coastal zones host a large percentage of global population and economical and productive activities and are in need of a constant monitoring. The C-wams project is focused at implementing a suite EO services targeting two growing sectors: Waste Water Treatment and Desalination plants. The coast of the United Arab Emirates (UAE) hosts some of the largest desalination plants in the world and their operation can affect and be affected by the status of the WQ near the coast: the local phenomenon known as Red Tide caused increasing damages in the last 4 years. Some actors are involved in this respect in the Persian gulf, among them the Environment Agency of Abu Dhabi (EAD). In UAE an historical study-case is being performed aimed at identifying Red Tide events using MERIS images, integrating them with other medium and higher resolution data. The present work describes its scenario and the preliminary results obtained.

  18. Chattonella and Fibrocapsa (Raphidophyceae): First observation of, potentially harmful, red tide organisms in Dutch coastal waters

    NASA Astrophysics Data System (ADS)

    Vrieling, E. G.; Koeman, R. P. T.; Nagasaki, K.; Ishida, Y.; Pererzak, L.; Gieskes, W. W. C.; Veenhuis, M.

    Species of the potentially toxic and red-tide-forming marine-phytoplankton genera Chattonella and Fibrocapsa (Raphidophyceae) were observed for the first time in 1991 in samples taken in Dutch coastal waters; they were again recorded and enumerated in the following years. Chattonella spp. cell numbers varied with the season, with a maximum in May or June in the Dutch Wadden Sea. Cell numbers of Chattonella and F. japonica Toriumi et Takano were up to 6.0·10 3 cells·dm -3 in the Dutch Wadden Sea, except at one station in June 1993 when over 10 4 cells·dm -3Chattonella were counted. In May 1993, a minor bloom (over 2.0·10 5 cells·dm -3) was observed at a station in the southern central North Sea, 100 km northwest of the island of Terschelling. The potentially neurotoxic species Chattonella marina (Subrahmanyan) Hara et Chihara was identified and discriminated from morphologically related species within the class of Raphidophyceae by immunofluorescence. F. japonica could only be clearly identified in live samples; in fixed samples cell morphology was severely affected. The identification of this species was supported by the presence of mucocysts, structures that can be observed readily by optical and electron microscopy.

  19. Selection for a red tide organism: physiological responses to the physical environment

    SciTech Connect

    Tyler, M.A.; Seliger, H.H.

    1981-03-01

    The dinoflagellate Prorocentrum mariae-lebouriae has specific physiological characteristics that allow it to participate in a subsurface transport from the southern Chesapeak Bay to the northern bay, where it upwells and forms red tides. A particular growth rate dependence both on temperature and salinity restricts its year-round distribution to the high-salinty southern bay. At summer temperatures, increased tolerance to low salinities allows rapid growth in the low-salinity waters of the northern bay. Positive phototaxis is proposed to act in conjunction with downwelling convergence at a frontal region to form the initial subsurface concentration maximum or lens. Repression of positive phototaxis at a salinity interface appears to prevent the subsurface concentrations from crossing the sharp halocline, retaining the lens population in northward-flowing bottom waters. Prorocentrum increases its pigment concentration and retains its photosynthetic capacity at the extremely low light intensities encountered during the 200-km northward transport. In nutrient-poor surface waters in summer, Prorocentrum migrates at night to the higher nutrient pycnocline region. The winter-spring phasing of the streamflows in both northern and southern bays may be used to predict the degree of Prorocentrum blooming in the northern bay in summer.

  20. Pumping bottom water to prevent Korean red tide damage caused by Cochlodinium polykrikoides Margalef.

    PubMed

    Cho, Eun Seob; Moon, Seong Yong; Shu, Young Sang; Hwang, Jae Dong; Youn, Seok Hyun

    2015-09-01

    Cochlodinium polykrikoides Margalef produces annual massive blooms in Korean coastal waters which cause great damage to aquaculture and fisheries. Although various methods have been developed to remove the red tide of C. polykrikoides, release of yellow loess has been regarded as the most desirable technique for mitigation for over 10 years. Each August, strong irradiation generates water column stratification separating warm surface from colder bottom waters. Water from a distance of 0 (St. 1), 5 (St. 2), 10 (St. 3), and 15 m (St. 4) was pumped by running a pump for 0, 10, 30 and 90 min and characterized water temperature, salinity collected, suspended solids, Chl-a, and phytoplankton including C. polykrikoides. After running for 30 min, was temperature and salinity in surface water was similar to those of bottom water, and water column stratification completely reversed after 90 min. Likewise, suspended solids, Chl-a, and total phytoplankton cell density decreased after 30 min, but C. polykrikoides did not show strong removal because of low cell density during sampling. However, the number of C. polykrikoides was significantly diluted (80%) after 90 min. These results suggested that pumping device was as an environmentally-friendly method convenient to be install in fish cages and effective to remove C. polykrikoides stratified water column conditions.

  1. Control of the red tide dinoflagellate Cochlodinium polykrikoides by ozone in seawater.

    PubMed

    Shin, Minjung; Lee, Hye-Jin; Kim, Min Sik; Park, Noh-Back; Lee, Changha

    2017-02-01

    The inactivation of C. polykrikoides, a red tide dinoflagellate, by ozonation was investigated in seawater by monitoring numbers of viable and total cells. Parameters affecting the inactivation efficacy of C. polykrikoides such as the ozone dose, initial cell concentration, pH, and temperature were examined. The viable cell number rapidly decreased in the initial stage of the reaction (mostly in 1-2 min), whereas the decrease in total cell number was relatively slow and steady. Increasing ozone dose and decreasing initial cell concentration increased the inactivation efficacy of C. polykrikoides, while increasing pH and temperature decreased the cell inactivation efficacy. The addition of humic acid (a promoter for the ozone decomposition) inhibited the inactivation of C. polykrikoides, whereas bicarbonate ion (an inhibitor for the ozone decomposition) accelerated the C. polykrikoides inactivation. Observations regarding the effects of pH, temperature, humic acid, and bicarbonate ion collectively indicate that the inactivation of C. polykrikoides by ozonation is mainly attributed to oxidative cell damages by molecular ozone, rather than by hydroxyl radical, produced during the ozone decomposition. At high ozone dose (e.g., 5 mg/L), hypobromous acid formed by the reaction of bromide with ozone may partially contribute to cell inactivation. The use of ozone of less than 1 mg/L produced 0.75-2.03 μg/L bromate.

  2. Making Space for Red Tide: Discolored Water and the Early Twentieth Century Bayscape of Japanese Pearl Cultivation.

    PubMed

    Ericson, Kjell

    2016-04-06

    "Red tide" has become a familiar shorthand for unusual changes in the color of ocean waters. It is intimately related both to blooms of creatures like dinoflagellates and to the devastating effects they pose to coastal fisheries. This essay tracks the early twentieth century emergence of discolored water as an aquacultural problem, known in Japan as akashio, and its trans-oceanic transformation into the terms and practices of "red tide" in the post-World War II United States. For Japan's "Pearl King" Mikimoto Kōkichi and his contacts in diverse marine scientific communities, the years-long cycle of guarding and cultivating a pearl oyster went together with the ascription of moral qualities to tiny creatures that posed a threat to farmed bayscapes of pearl monoculture. As akashio, discolored water went from curiosity to marine livestock pest, one that at times left dead pearl oysters in its wake. Red tide arose from the sustained study of the mechanisms by which changes in the biological and chemical composition of seawater might become deadly to exclusively-claimed shellfish along Japanese coastlines, but came to be seen as a way to understand aquatic manifestations of harm in other parts of the littoral world.

  3. The human health effects of Florida red tide (FRT) blooms: an expanded analysis.

    PubMed

    Hoagland, Porter; Jin, Di; Beet, Andrew; Kirkpatrick, Barbara; Reich, Andrew; Ullmann, Steve; Fleming, Lora E; Kirkpatrick, Gary

    2014-07-01

    Human respiratory and digestive illnesses can be caused by exposures to brevetoxins from blooms of the marine alga Karenia brevis, also known as Florida red tide (FRT). K. brevis requires macro-nutrients to grow; although the sources of these nutrients have not been resolved completely, they are thought to originate both naturally and anthropogenically. The latter sources comprise atmospheric depositions, industrial effluents, land runoffs, or submerged groundwater discharges. To date, there has been only limited research on the extent of human health risks and economic impacts due to FRT. We hypothesized that FRT blooms were associated with increases in the numbers of emergency room visits and hospital inpatient admissions for both respiratory and digestive illnesses. We sought to estimate these relationships and to calculate the costs of associated adverse health impacts. We developed environmental exposure-response models to test the effects of FRT blooms on human health, using data from diverse sources. We estimated the FRT bloom-associated illness costs, using extant data and parameters from the literature. When controlling for resident population, a proxy for tourism, and seasonal and annual effects, we found that increases in respiratory and digestive illnesses can be explained by FRT blooms. Specifically, FRT blooms were associated with human health and economic effects in older cohorts (≥55 years of age) in six southwest Florida counties. Annual costs of illness ranged from $60,000 to $700,000 annually, but these costs could exceed $1.0 million per year for severe, long-lasting FRT blooms, such as the one that occurred during 2005. Assuming that the average annual illness costs of FRT blooms persist into the future, using a discount rate of 3%, the capitalized costs of future illnesses would range between $2 and 24 million.

  4. Phosphorus cycling in the red tide incubator region of monterey bay in response to upwelling.

    PubMed

    Mackey, Katherine R M; Mioni, Cécile E; Ryan, John P; Paytan, Adina

    2012-01-01

    This study explores the cycling of phosphorus (P) in the euphotic zone following upwelling in northeastern Monterey Bay (the Red Tide Incubator region) of coastal California, with particular emphasis on how bacteria and phytoplankton that form harmful algal blooms mediate and respond to changes in P availability. In situ measurements of nutrient concentrations, phytoplankton community composition, and cell-specific alkaline phosphatase (AP) activity (determined via enzyme-labeled fluorescence assay) were measured during three cruises. Upwelling led to a 10-fold increase in dissolved inorganic (DIP) in surface waters, reaching ∼0.5 μmol L(-1). This DIP was drawn down rapidly as upwelling relaxed over a period of 1 week. Ratios of nitrate to DIP drawdown (∼5:1, calculated as the change in nitrate divided by the change in DIP) were lower than the Redfield ratio of 16:1, suggesting that luxury P uptake was occurring as phytoplankton bloomed. Dissolved organic (DOP) remained relatively constant (∼0.3 μmol L(-1)) before and immediately following upwelling, but doubled as upwelling relaxed, likely due to phytoplankton excretion and release during grazing. This transition from a relatively high DIP:DOP ratio to lower DIP:DOP ratio was accompanied by a decline in the abundance of diatoms, which had low AP activity, toward localized, spatially heterogeneous blooms of dinoflagellates in the genera Prorocentrum, Ceratium, Dinophysis, Alexandrium, and Scrippsiella that showed high AP activity regardless of ambient DIP levels. A nutrient addition incubation experiment showed that phytoplankton growth was primarily limited by nitrate, followed by DIP and DOP, suggesting that P regulates phytoplankton physiology and competition, but is not a limiting nutrient in this region. AP activity was observed in bacteria associated with lysed cell debris and aggregates of particulate organic material, where it may serve to facilitate P regeneration, as well as affixed to

  5. Allelopathic effects of macroalga Corallina pilulifera on the red-tide forming alga Heterosigma akashiwo under laboratory conditions

    NASA Astrophysics Data System (ADS)

    Wang, Renjun; Tang, Xuexi

    2016-03-01

    Over the past few years, harmful algal blooms (HABs), such as red tides, have been frequently observed in coastal zones worldwide. The natural allelopathic interactions among macroalgae and red tide microalgae can alter the structure and succession of aquatic ecosystems. We investigated the influence of four environmental factors (temperature, salinity, light, and pH) on the allelopathic effects of the macroalgae Corallina pilulifera on red-tide forming Heterosigma akashiwo under laboratory conditions. Each of the factors had four levels: temperature (15, 20, 25, and 30°C), salinity (10, 20, 30, and 40), light (20, 100, 200 and 400 μmol/(m2•s)), and pH (5.5, 7, 8.5, and 10. Two-factor experiments were designed for each two environmental factors, with six combination treatments (temperature-salinity, temperature-light, temperature-pH, salinity-light, salinity-pH, and light-pH). Results showed that the allelopathic effect was significantly influenced by temperature, salinity, light, and pH. As single factors, the low temperature (15°C), low salinity (10), high-intensity light (400 μmol/(m2•s)), and high pH (10) treatments substantially enhanced the allelopathic effect. The strongest allelopathic effect of C. pilulifera on H. akashiwo was observed under the following treatments: 15°C and salinity of 40, 25°C and pH 10, 25°C with medium- to high-intensity light at 200-400 μmol/(m 2 •s), 400 μmol/(m2•s) and salinity of 10, 400 μmol/(m2•s) and pH 10, and pH 10 with a salinity of 40.

  6. Bio-optical characteristics of a red tide induced by Mesodinium rubrum in the Cariaco Basin, Venezuela

    NASA Astrophysics Data System (ADS)

    Guzmán, Laurencia; Varela, Ramón; Muller-Karger, Frank; Lorenzoni, Laura

    2016-08-01

    The bio-optical changes of the water induced by red tides depend on the type of organism present, and the spectral characterization of such changes can provide useful information on the organism, abundance and distribution. Here we present results from the bio-optical characterization of a non-toxic red tide induced by the autotrophic ciliate Mesodinium rubrum. Particle absorption was high [ap(440) = 1.78 m- 1], as compared to measurements done in the same region [ap(440) = 0.09 ± 0.06 m- 1], with detrital components contributing roughly 11% [ad(440) = 0.19 m- 1]. The remainder was attributed to absorption by phytoplankton pigments [aph(440) = 1.60 m- 1]. These aph values were ~ 15 times higher than typical values for these waters. High chlorophyll a concentrations were also measured (52.73 μg L- 1), together with alloxanthin (9.52 μg L- 1) and chlorophyll c (6.25 μg L- 1). This suite of pigment is typical of the algal class Cryptophyceae, from which Mesodinium obtains its chloroplasts. Remote sensing reflectance showed relatively low values [Rrs(440) = 0.0007 sr- 1], as compared to other Rrs values for the region under high bloom conditions [Rrs(440) = 0.0028 sr- 1], with maxima at 388, 484, 520, 596 and 688 nm. Based on the low reflection in the green-yellow, as compared to other red tides, we propose a new band ratio [Rrs(688)/Rrs(564)] to identify blooms of this particular group of organisms.

  7. Effects of solar ultraviolet radiation on photosynthesis of the marine red tide alga Heterosigma akashiwo (Raphidophyceae).

    PubMed

    Gao, Kunshan; Guan, Wanchun; Helbling, E Walter

    2007-02-01

    In order to assess the short- and long-term impacts of UV radiation (UVR, 280-400nm) on the red tide alga, Heterosigma akashiwo, we exposed the cells to three different solar radiation treatments (PAB: 280-700nm, PA: 320-700nm, P: 400-700nm) under both solar and artificial radiation. A significant decrease in the effective quantum yield (Y) during high irradiance periods (i.e., local noon) was observed, but the cells partially recovered during the evening hours. Exposure to high irradiances for 15, 30, and 60min under a solar simulator followed by the recovery (8h) under dark, 9 and 100micromolphotonsm(-2)s(-1) of PAR, highlighted the importance of the irradiance level during the recovery period. Regardless the radiation treatments, the highest recovery (both in rate and total Y) was found at a PAR irradiance of 9micromolphotonsm(-2)s(-1), while the lowest was observed at 100micromolphotonsm(-2)s(-1). In all experiments, PAR was responsible for most of the observed inhibition; nevertheless, the cells exposed only to PAR had the highest recovery in any condition, as compared to the other radiation treatments. In long-term experiments (10 days) using semi-continuous cultures, there was a significant increase of UV-absorbing compounds (UV(abc)) per cell from 1.2 to >4x10(-6)microgUV(abc)cell(-1) during the first 3-5 days of exposure to solar radiation. The highest concentration of UV(abc) was found in samples exposed in the PAB as compared to PA and P treatments. Growth rates (mu) mimic the behavior of UV-absorbing compounds, and during the first 5 days mu increased from <0.2 to ca. 0.8, and stayed relatively constant at this value during the rest of the experiment. The inhibition of the Y decreased with increasing acclimation of cells. All our data indicates that H. akashiwo is a sensitive species, but was able acclimate relatively fast (3-5 days) synthesizing UV-absorbing compounds and thus reducing any impact either on photosystem II or on growth.

  8. Microbial modulation in the biomass and toxin production of a red-tide causing alga.

    PubMed

    Zheng, T L; Su, J Q; Maskaoui, K; Yu, Z M; Hu, Z; Xu, J S; Hong, H S

    2005-01-01

    -control of red-tides was discussed.

  9. Phosphorus Cycling in the Red Tide Incubator Region of Monterey Bay in Response to Upwelling

    PubMed Central

    Mackey, Katherine R. M.; Mioni, Cécile E.; Ryan, John P.; Paytan, Adina

    2012-01-01

    This study explores the cycling of phosphorus (P) in the euphotic zone following upwelling in northeastern Monterey Bay (the Red Tide Incubator region) of coastal California, with particular emphasis on how bacteria and phytoplankton that form harmful algal blooms mediate and respond to changes in P availability. In situ measurements of nutrient concentrations, phytoplankton community composition, and cell-specific alkaline phosphatase (AP) activity (determined via enzyme-labeled fluorescence assay) were measured during three cruises. Upwelling led to a 10-fold increase in dissolved inorganic (DIP) in surface waters, reaching ∼0.5 μmol L−1. This DIP was drawn down rapidly as upwelling relaxed over a period of 1 week. Ratios of nitrate to DIP drawdown (∼5:1, calculated as the change in nitrate divided by the change in DIP) were lower than the Redfield ratio of 16:1, suggesting that luxury P uptake was occurring as phytoplankton bloomed. Dissolved organic (DOP) remained relatively constant (∼0.3 μmol L−1) before and immediately following upwelling, but doubled as upwelling relaxed, likely due to phytoplankton excretion and release during grazing. This transition from a relatively high DIP:DOP ratio to lower DIP:DOP ratio was accompanied by a decline in the abundance of diatoms, which had low AP activity, toward localized, spatially heterogeneous blooms of dinoflagellates in the genera Prorocentrum, Ceratium, Dinophysis, Alexandrium, and Scrippsiella that showed high AP activity regardless of ambient DIP levels. A nutrient addition incubation experiment showed that phytoplankton growth was primarily limited by nitrate, followed by DIP and DOP, suggesting that P regulates phytoplankton physiology and competition, but is not a limiting nutrient in this region. AP activity was observed in bacteria associated with lysed cell debris and aggregates of particulate organic material, where it may serve to facilitate P regeneration, as well as affixed to

  10. Brevisulcatic acids, marine ladder-frame polyethers from the red tide dinoflagellate Karenia brevisulcata in New Zealand.

    PubMed

    Suzuki, Rina; Irie, Raku; Harntaweesup, Yanit; Tachibana, Kazuo; Holland, Patrick T; Harwood, D Tim; Shi, Feng; Beuzenberg, Veronica; Itoh, Yoshiyuki; Pascal, Steven; Edwards, Patrick J B; Satake, Masayuki

    2014-11-21

    The isolation and structural determination of new marine ladder-frame polyethers, brevisulcatic acids-1 (1) and -4 (2) are reported. Brevisulcatic acids were isolated from the dinoflagellate Karenia brevisulcata, which was identified as the causative species of a major red tide event in New Zealand in 1998. The ether ring composition and a β-hydroxy, γ-methylene valeric acid side chain of 1 and 2 are common, but 2 has a γ-lactone as the 5-membered A-ring while 1 is the seco acid analogue. Compound 2 has structural and bioactivity similarities to brevetoxin A.

  11. Linking groundwater-borne nutrients and dinoflagellate red-tide outbreaks in the southern sea of Korea using a Ra tracer

    NASA Astrophysics Data System (ADS)

    Lee, Yong-Woo; Kim, Guebuem

    2007-01-01

    We have measured nutrients, photosynthetic pigments, and two radium isotopes ( 223Ra and 224Ra) in coastal groundwater and seawater during the summer of 2002 and 2003 in the southern sea of Korea, where harmful dinoflagellate blooms (hereafter red tides) have been occurring every year since 1982. In this region, the amount of submarine groundwater discharge (SGD) is known to be two orders of magnitude higher than the surface runoff. Good correlations of dissolved inorganic nitrogen (DIN) and silicate (DSi) with groundwater-borne 224Ra (half life = 3.66 days) in the initial red-tide waters of 2002 confirm that the source of these nutrients is SGD. In addition, the DIN/DIP ratios in 2002 and total dissolved nitrogen/phosphorus (TDN/TDP) ratios in 2003 in red-tide waters ranged from 30 to 300, similar to those observed in groundwater. The spatial and temporal variations of nutrients and photosynthetic pigments showed that red tides broke out when DIN or DIP (dissolved inorganic phosphorus) were almost depleted, limiting the growth of diatoms. Thus, our observations reveal that the emergence of harmful dinoflagellate red tides might be facilitated by inter-specific competition of phytoplankton species when inorganic nutrients are limited and dissolved organic nutrients, converted from groundwater-borne nutrients, are sufficient.

  12. Isolation on the West Florida Shelf with implications for red tides and pollutant dispersal in the Gulf of Mexico.

    PubMed

    Olascoaga, M J

    2010-01-01

    Analysis of year-long drifter trajectories and records of simulated surface Lagrangian Coherent Structures (LCSs) have suggested the presence of a resilient Cross-Shelf Transport Barrier (CSTB) on the West Florida Shelf (WFS). The CSTB was conjectured to provide a large degree of isolation, which is consequential for the fueling of red tides on the southern WFS by nutrients possibly released by rivers and canals directly on the region. Here this conjecture is thoroughly tested by identifying LCSs as well as performing tracer advection calculations based on seven-year-long records of surface and subsurface currents produced by a HYbrid-Coordinate Ocean Model (HYCOM) simulation of the Gulf of Mexico (GoM). The identified LCSs suggest that the CSTB extends downward in the water column. The tracer calculations suggest that, while the majority of the nutrients possibly released by rivers and canals directly on the southern WFS are retained within the region for long times, only a small fraction of the nutrients possibly released by rivers outside the WFS reach the southern WFS, mainly accompanying shoreward excursions of the CSTB. These results add importance to the role played by the CSTB in controlling red tide development on the WFS. Implications of the results for the dispersal of pollutants, such as oil, in the GoM are discussed.

  13. Isolation on the West Florida Shelf with implications for red tides and pollutant dispersal in the Gulf of Mexico

    PubMed Central

    Olascoaga, M. J.

    2011-01-01

    Analysis of year-long drifter trajectories and records of simulated surface Lagrangian Coherent Structures (LCSs) have suggested the presence of a resilient Cross-Shelf Transport Barrier (CSTB) on the West Florida Shelf (WFS). The CSTB was conjectured to provide a large degree of isolation, which is consequential for the fueling of red tides on the southern WFS by nutrients possibly released by rivers and canals directly on the region. Here this conjecture is thoroughly tested by identifying LCSs as well as performing tracer advection calculations based on seven-year-long records of surface and subsurface currents produced by a HYbrid-Coordinate Ocean Model (HYCOM) simulation of the Gulf of Mexico (GoM). The identified LCSs suggest that the CSTB extends downward in the water column. The tracer calculations suggest that, while the majority of the nutrients possibly released by rivers and canals directly on the southern WFS are retained within the region for long times, only a small fraction of the nutrients possibly released by rivers outside the WFS reach the southern WFS, mainly accompanying shoreward excursions of the CSTB. These results add importance to the role played by the CSTB in controlling red tide development on the WFS. Implications of the results for the dispersal of pollutants, such as oil, in the GoM are discussed. PMID:22287830

  14. Isolation on the West Florida Shelf with implications for red tides and pollutant dispersal in the Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Olascoaga, M. J.

    2010-12-01

    Analysis of year-long drifter trajectories and records of simulated surface Lagrangian Coherent Structures (LCSs) have suggested the presence of a resilient Cross-Shelf Transport Barrier (CSTB) on the West Florida Shelf (WFS). The CSTB was conjectured to provide a large degree of isolation, which is consequential for the fueling of red tides on the southern WFS by nutrients possibly released by rivers and canals directly on the region. Here this conjecture is thoroughly tested by identifying LCSs as well as performing tracer advection calculations based on seven-year-long records of surface and subsurface currents produced by a HYbrid-Coordinate Ocean Model (HYCOM) simulation of the Gulf of Mexico (GoM). The identified LCSs suggest that the CSTB extends downward in the water column. The tracer calculations suggest that, while the majority of the nutrients possibly released by rivers and canals directly on the southern WFS are retained within the region for long times, only a small fraction of the nutrients possibly released by rivers outside the WFS reach the southern WFS, mainly accompanying shoreward excursions of the CSTB. These results add importance to the role played by the CSTB in controlling red tide development on the WFS. Implications of the results for the dispersal of pollutants, such as oil, in the GoM are discussed.

  15. A NUMERICAL ANALYSIS OF LANDFALL OF THE 1979 RED TIDE OF KARENIA BREVIS ALONG THE WEST COAST OF FLORIDA. (R827085)

    EPA Science Inventory

    Abstract

    A simple ecological model, coupled to a primitive equation circulation model, is able to replicate the observed alongshore transport of the toxic dinoflagellate Karenia brevis on the West Florida shelf during a fall red tide in 1979. Initial land fall o...

  16. A NUMERICAL ANALYSIS OF LANDFALL OF THE 1979 RED TIDE OF KARENIA BREVIS ALONG THE WEST COAST OF FLORIDA. (R827085)

    EPA Science Inventory

    Abstract

    A simple ecological model, coupled to a primitive equation circulation model, is able to replicate the observed alongshore transport of the toxic dinoflagellate Karenia brevis on the West Florida shelf during a fall red tide in 1979. Initial land fall o...

  17. Inhibitory activity of an extract from a marine bacterium Halomonas sp. HSB07 against the red-tide microalga Gymnodinium sp. (Pyrrophyta)

    NASA Astrophysics Data System (ADS)

    Liu, Juan; Li, Fuchao; Liu, Ling; Jiang, Peng; Liu, Zhaopu

    2013-11-01

    In recent years, red tides occurred frequently in coastal areas worldwide. Various methods based on the use of clay, copper sulfate, and bacteria have been successful in controlling red tides to some extent. As a new defensive agent, marine microorganisms are important sources of compounds with potent inhibitory bioactivities against red-tide microalgae, such as Gymnodinium sp. (Pyrrophyta). In this study, we isolated a marine bacterium, HSB07, from seawater collected from Hongsha Bay, Sanya, South China Sea. Based on its 16S rRNA gene sequence and biochemical characteristics, the isolated strain HSB07 was identified as a member of the genus Halomonas. A crude ethyl acetate extract of strain HSB07 showed moderate inhibition activity against Gymnodinium sp. in a bioactive prescreening experiment. The extract was further separated into fractions A, B, and C by silica gel column chromatography. Fractions B and C showed strong inhibition activities against Gymnodinium. This is the first report of inhibitory activity of secondary metabolites of a Halomonas bacterium against a red-tide-causing microalga.

  18. Effects of Florida Red Tides on histone variant expression and DNA methylation in the Eastern oyster Crassostrea virginica.

    PubMed

    Gonzalez-Romero, Rodrigo; Suarez-Ulloa, Victoria; Rodriguez-Casariego, Javier; Garcia-Souto, Daniel; Diaz, Gabriel; Smith, Abraham; Pasantes, Juan Jose; Rand, Gary; Eirin-Lopez, Jose M

    2017-03-07

    Massive algal proliferations known as Harmful Algal Blooms (HABs) represent one of the most important threats to coastal areas. Among them, the so-called Florida Red Tides (FRTs, caused by blooms of the dinoflagellate Karenia brevis and associated brevetoxins) are particularly detrimental in the southeastern U.S., causing high mortality rates and annual losses in excess of $40 million. The ability of marine organisms to cope with environmental stressors (including those produced during HABs) is influenced by genetic and epigenetic mechanisms, the latter resulting in phenotypic changes caused by heritable modifications in gene expression, without involving changes in the genetic (DNA) sequence. Yet, studies examining cause-effect relationships between environmental stressors, specific epigenetic mechanisms and subsequent responses are still lacking. The present work contributes to increase this knowledge by investigating the effects of Florida Red Tides on two types of mechanisms participating in the epigenetic memory of Eastern oysters: histone variants and DNA methylation. For that purpose, a HAB simulation was conducted in laboratory conditions, exposing oysters to increasing concentrations of K. brevis. The obtained results revealed, for the first time, the existence of H2A.X, H2A.Z and macroH2A genes in this organism, encoding histone variants potentially involved in the maintenance of genome integrity during responses to the genotoxic effect of brevetoxins. Additionally, an increase in H2A.X phosphorylation (γH2A.X, a marker of DNA damage) and a decrease in global DNA methylation were observed as the HAB simulation progressed. Overall, the present work provides a basis to better understand how epigenetic mechanisms participate in responses to environmental stress in marine invertebrates, opening new avenues to incorporate environmental epigenetics approaches into management and conservation programs.

  19. Coyote (Canis latrans) and domestic dog (Canis familiaris) mortality and morbidity due to a Karenia brevis red tide in the Gulf of Mexico.

    PubMed

    Castle, Kevin T; Flewelling, Leanne J; Bryan, John; Kramer, Adam; Lindsay, James; Nevada, Cheyenne; Stablein, Wade; Wong, David; Landsberg, Jan H

    2013-10-01

    In October 2009, during a Karenia brevis red tide along the Texas coast, millions of dead fish washed ashore along the 113-km length of Padre Island National Seashore (PAIS). Between November 2009 and January 2010, at least 12 coyotes (Canis latrans) and three domestic dogs (Canis familiaris) died or were euthanized at PAIS or local veterinary clinics because of illness suspected to be related to the red tide. Another red tide event occurred during autumn 2011 and, although fewer dead fish were observed relative to the 2009 event, coyotes again were affected. Staff at PAIS submitted carcasses of four coyotes and one domestic dog from November 2009 to February 2010 and six coyotes from October to November 2011 for necropsy and ancillary testing. High levels of brevetoxins (PbTxs) were measured by enzyme-linked immunosorbent assay in seven of the coyotes and the dog, with concentrations up to 634 ng PbTx-3 eq/g in stomach contents, 545 ng PbTx-3 eq/g in liver, 195 ng PbTx-3 eq/g in kidney, and 106 ng PbTx-3 eq/mL in urine samples. Based on red tide presence, clinical signs, and postmortem findings, brevetoxicosis caused by presumptive ingestion of toxic dead fish was the likely cause of canid deaths at PAIS. These findings represent the first confirmed report of terrestrial mammalian wildlife mortalities related to a K. brevis bloom. The implications for red tide impacts on terrestrial wildlife populations are a potentially significant but relatively undocumented phenomenon.

  20. Tide generator

    SciTech Connect

    Feltenberger, B.D.

    1981-06-16

    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.

  1. The distribution pattern of the red tide and the process of oxygen depletion in the coastal brackish Lake Nakaumi, Southwest Japan

    NASA Astrophysics Data System (ADS)

    Seto, K.; Miyagi, H.; Katsuki, K.; Takata, H.; Dettman, D. L.

    2007-12-01

    Lake Nakaumi is a coastal brackish water lake formed by the Yumigahama peninsula. The water mass of Lake Nakaumi has two-layer structures. The main halocline divided to Nakaumi Surface Water (NSW) of the intermediate saline water (around 15psu) and Nakaumi Bottom Water (NBW) of the high saline water (about 30psu). Recently, the occurrence of red tide bloom is frequently observed in the lake. The main purpose of this study is to understand the influence of the red tide on the lake environment (The especially, dissolved oxygen in NBW). In this study, we investigated the water quality during April to June 2006 when the lake has experienced extensive occurrence of red tide, and we also monitored the chlorophyll-a (Chl-a) distribution by in vivo fluorometric method. ? Red tide blooms were observed almost in the entire area of Lake Nakaumi in spring, 2006. The water surface showed reddish brown color due to the occurrence of red tide. In the composition of the phytoplankton, Prorocentrum minimum was the dominant species during the red tide. The composition of the phytoplankton rapidly changed during May 27 to 30, and it shifts to the community in which Cyanophyceae is dominant. During that time, the Chl-a concentration rapidly decreased. Based on the vertical distribution of the Chl-a concentration, the red tide at our observation period was divided to 3 phases. In Phase I (March 18th to April 22nd), the Chl-a concentration was relatively low, and homogenous distribution in NSW. In Phase II (April 22nd to May 10th), the Chl-a concentration shows high value, and the peak of Chl-a concentration was present at small-scale and main halocline in the whole water column. In Phase III (May 10th to May 27th), the peak concentrations of Chl-a were distributed around small-scale halocline in NSW and main halocline. In NBW, the Chl-a concentration was low. In Phase I, the dissolved oxygen (DO) concentration of NBW shows 5~7mg/l. During Phase II, DO in NBW decreased. The decreasing

  2. Florida red tide and human health: a pilot beach conditions reporting system to minimize human exposure.

    PubMed

    Kirkpatrick, Barbara; Currier, Robert; Nierenberg, Kate; Reich, Andrew; Backer, Lorraine C; Stumpf, Richard; Fleming, Lora; Kirkpatrick, Gary

    2008-08-25

    With over 50% of the US population living in coastal counties, the ocean and coastal environments have substantial impacts on coastal communities. While many of the impacts are positive, such as tourism and recreation opportunities, there are also negative impacts, such as exposure to harmful algal blooms (HABs) and water borne pathogens. Recent advances in environmental monitoring and weather prediction may allow us to forecast these potential adverse effects and thus mitigate the negative impact from coastal environmental threats. One example of the need to mitigate adverse environmental impacts occurs on Florida's west coast, which experiences annual blooms, or periods of exuberant growth, of the toxic dinoflagellate, Karenia brevis. K. brevis produces a suite of potent neurotoxins called brevetoxins. Wind and wave action can break up the cells, releasing toxin that can then become part of the marine aerosol or sea spray. Brevetoxins in the aerosol cause respiratory irritation in people who inhale it. In addition, asthmatics who inhale the toxins report increase upper and lower airway symptoms and experience measurable changes in pulmonary function. Real-time reporting of the presence or absence of these toxic aerosols will allow asthmatics and local coastal residents to make informed decisions about their personal exposures, thus adding to their quality of life. A system to protect public health that combines information collected by an Integrated Ocean Observing System (IOOS) has been designed and implemented in Sarasota and Manatee Counties, Florida. This system is based on real-time reports from lifeguards at the eight public beaches. The lifeguards provide periodic subjective reports of the amount of dead fish on the beach, apparent level of respiratory irritation among beach-goers, water color, wind direction, surf condition, and the beach warning flag they are flying. A key component in the design of the observing system was an easy reporting pathway for

  3. Florida Red Tide and Human Health: A Pilot Beach Conditions Reporting System to Minimize Human Exposure

    PubMed Central

    Kirkpatrick, Barbara; Currier, Robert; Nierenberg, Kate; Reich, Andrew; Backer, Lorraine C.; Stumpf, Richard; Fleming, Lora; Kirkpatrick, Gary

    2008-01-01

    With over 50% of the US population living in coastal counties, the ocean and coastal environments have substantial impacts on coastal communities. While may of the impacts are positive, such as tourism and recreation opportunities, there are also negative impacts, such as exposure to harmful algal blooms (HABs) and water borne pathogens. Recent advances in environmental monitoring and weather prediction may allow us to forecast these potential adverse effects and thus mitigate the negative impact from coastal environmental threats. One example of the need to mitigate adverse environmental impacts occurs on Florida’s west coast, which experiences annual blooms, or periods of exuberant growth, of the toxic dinoflagellate, Karenia brevis. K. brevis produces a suite of potent neurotoxins called brevetoxins. Wind and wave action can break up the cells, releasing toxin that can then become part of the marine aerosol or sea spray. Brevetoxins in the aerosol cause respiratory irritation in people who inhale it. In addition, asthmatics who inhale the toxins report increase upper and lower airway lower symptoms and experience measurable changes in pulmonary function. Real-time reporting of the presence or absence of these toxic aerosols will allow asthmatics and local coastal residents to make informed decisions about their personal exposures, thus adding to their quality of life. A system to protect public health that combines information collected by an Integrated Ocean Observing System (IOOS) has been designed and implemented in Sarasota and Manatee Counties, Florida. This system is based on real-time reports from lifeguards at the eight public beaches. The lifeguards provide periodic subjective reports of the amount of dead fish on the beach, apparent level of respiratory irritation among beach-goers, water color, wind direction, surf condition, and the beach warning flag they are flying. A key component in the design of the observing system was an easy reporting

  4. A filterable lytic agent obtained from a red tide bloom that caused lysis of Karenia brevis (Gymnodinum breve) cultures

    USGS Publications Warehouse

    2002-01-01

    A filterable lytic agent (FLA) was obtained from seawater in the southeastern Gulf of Mexico during a red tide bloom that caused lysis of Karenia brevis (formerly Gymnodinium breve) Piney Island. This agent was obtained from <0.2µ  filtrates that were concentrated by ultrafiltration using a 100 kDa filter. The FLA was propagated by passage on K. brevis cultures, and the filtered supernatants of such cultures resulted in K. brevis lysis when added to such cultures. The lytic activity was lost upon heating to 65°C or by 0.02 µm filtration. Epifluorescence and transmission electron microscopy (TEM) of supernatants of K. brevis cultures treated with the lytic agent indicated a high abundance of viral particles (4 × 109 to 7 × 109 virus-like particles [VLPs] ml–1) compared to control cultures (~107 ml–1). However, viral particles were seldom found in TEM photomicrograph thin sections of lysing K. brevis cells. Although a virus specific for K. brevis may have been the FLA, other explanations such as filterable bacteria or bacteriophages specific for bacteria associated with the K. brevis cultures cannot be discounted.

  5. The effects of nitrogen, phosphorus, vitamins and trace metals on the growth of the red tide organism Prorocentrum Micans

    NASA Astrophysics Data System (ADS)

    Wang, Zheng-Fang; Zhang, Qing; Gong, Min

    1995-12-01

    Laboratory culture experiments showed that <100μ mol/L nitrate, amonium or mixture of amino acids promote the growth of the red tide organism Prorocentrum micans Ehrenb, but that >100μmol/L of ammonium, or mixture of glycine and glutamate was harmful to growth, and that orthophosphate was P. micans’ main phosphorous source in the ocean. Presence of 80μ mol/L EDTA, 0.5 to 1 μmol/L Fe3+, 1.0 to 20.0 μ mol/L Mn2+ 0.1 to 0.4 μmol/L Co2+ in the culture medium could improve the growth of P. micans. Vitamin B1 promoted growth, but vitamin B12 and biotin did not. The estimated minimum cell quotas ( q o) for nitrogen and phosphorus being 0.74 pmole/cell and 0.045 pmole/cell show that phosphorus (more than nitrogen) limits the growth of P. micans in the study area.

  6. [Distribution of phytoplankton and water dynamical environmental factors in high red tide occurrence area of Changjiang River estuary].

    PubMed

    Zhu, Genhai; Xu, Weiyi; Zhu, Dedi; Shi, Qingsong; Zhang, Jian

    2003-07-01

    Species composition and cell abundance of phytoplankton, and its relations with environmental factors were investigated in the Changjiang River estuary of east China sea (30 degrees 50'-31 degrees 50'N, 121 degrees 50'-123 degrees 00'E). A total of 110 taxa belonging to 45 genera of phytoplankton in the investigation area were identified. The main species of phytoplankton resulted in red tide were Skeletonema costatum and Prorocentrum dentatum, etc. Phytoplankton abundance in the day was higher than that at night. The vertical distribution of phytoplankton in different water bodies was not obvious. The ecological groups of phytoplankton were freshwater group, estuarine and brackish water and low salinity group in the coast, high salinity and warm water group in off-sea, and widely ranging group. The abundance of phytoplankton in the Changjiang River estuary was 1.6 x 10(3)-75.2 x 10(3) ind.dm-3. The species composition and cell abundance of phytoplankton were related to the freshwater pouring into the Changjiang River estuary. The three waters in the area affecting the distribution of phytoplankton were the Changjiang River estuary water, freshwater, and warm water from outsea.

  7. [Illumination's effect on the growth and nitrate reductase activity of typical red-tide algae in the East China Sea].

    PubMed

    Li, Hong-mei; Shi, Xiao-yong; Ding, Yan-yan; Tang, Hong-jie

    2013-09-01

    Two typical red-tide algae, Skeletonema costatum and Prorocentrum donghaiense were selected as studied objects. The nitrate reductase activity (NRA) and the growth of the two algae under different illuminations through incubation experiment were studied. The illumination condition was consistent with in situ. Results showed that P. donghaiense and S. costatum could grow normally in the solar radiation ranged from 30-60 W x m(-2), and the growth curve was "S" type. However, when solar radiation was below 9 W x m(-2), the two alga could hardly grow. In the range of 0-60 W x m(-2), three parameters (NRAmax, micro(max), Bf) increased with the increasing of light intensity, indicating that the light intensity can influence the grow of alga indirectly through influencing the nitrate reductase activity. The micro(max) and NRAmax in unite volume of Skeletonema costatum were higher than those of Prorocentrum donghaiense, indicating that Skeletonema costatum can better utilize the nitrate than Prorocentrum donghaiense.

  8. Lipid and fatty acid contents in red tides from tropical fish ponds of the coastal water of South China Sea.

    PubMed

    Shamsudin, L

    1996-01-01

    Microplanktonic red tide blooms (dominated by dinoflagellates) were observed in brackish water fish ponds of Terengganu between March 1992 to January 1993. The first short-lived bloom (2-3 days) occurred in October 1992 while the second long-lived bloom (6-7 days) occurred in January 1993. The dominant dinoflagellate species comprised of Peridinium quinquecorne (> 90% total cell count) with considerable proportion of Protoperidinium excentricum. Ciliophora consisting of Tintinopsis sp. and Favella sp. were also present during the bloom period. The total ash, chlorophyll, phaeopigment, lipid and fatty acid content of the microplankton were studied. Considerable amounts (6-11% of the total fatty acid) of the polyunsaturated fatty acid 18:3w3 (linolenic acid) were present in the microplankton. However, high amounts of 20:5w3 (eicosapentanoic acid) and 22:6w3 (docosahexaenoic acid) were present with variable but usually high amounts of 22:4w6 and 22:5w6 acids. The latter microplankton bloom contained higher amounts of 20:5w3 and 22:6w3 acids than the earlier bloom. Lipid content were three to five times higher than chlorophyll a. There was an increase with successive day after bloom outbreak in the relative proportion of total C18, C20, and C22 fatty acid components. The algae microplankton contained the w3-polyunsaturated fatty acids (PUFAs) probably needed for the growth and survival rate of grazing pond animals.

  9. URGORRI COMPLANATUS GEN. ET SP. NOV. (CRYPTOPHYCEAE), A RED-TIDE-FORMING SPECIES IN BRACKISH WATERS(1).

    PubMed

    Laza-Martínez, Aitor

    2012-04-01

    The morphology, ultrastructure, phylogeny, and ecology of a new red-tide-forming cryptomonad, Urgorri complanatus Laza-Martínez gen. et sp. nov., is described. U. complanatus has been collected in southwestern European estuaries, blooming in the inner reaches of several of them. The estuarine character of the species is also supported by its in vitro salinity preferences, showing a maximum growth rate at 10 psu. U. complanatus is a distinctive species and can be easily distinguished by LM from other known brackish and marine species. Cells are dorsoventrally flattened. The plastid has two anterior lobes. One pyrenoid is located in each of the lobes, and a third one on the posterior part. Thylakoids are arranged in pairs and do not penetrate pyrenoids. The plastid is reddish due to the presence of the phycoerythrin Cr-PE545. An orange discoidal eyespot lies beneath the nucleus, in the posterior ventral face of the plastid. A long furrow runs from the vestibulum, and a gullet is lacking. The periplast is composed of an inner sheet. The nuclear 18S rDNA based molecular analysis reveals U. complanatus is not related to any of the main cryptomonad lineages. Based on ultrastructural and pigment data, the most probable relatives are those merged under the family Geminigeraceae. Its lack of derived characters, together with the presence of characters proposed in previous studies to be primitive, suggests Urgorri could be considered representative of the cryptophycean ancestral character state.

  10. A 1-D simulation analysis of the development and maintenance of the 2001 red tide of the ichthyotoxic dinoflagellate Karenia brevis on the West Florida shelf

    NASA Astrophysics Data System (ADS)

    Lenes, J. M.; Darrow, B. P.; Walsh, J. J.; Jolliff, J. K.; Chen, F. R.; Weisberg, R. H.; Zheng, L.

    2012-06-01

    A one-dimensional (1-D) ecological model, HABSIM, examined the initiation and maintenance of the 2001 red tide on the West Florida shelf (WFS). Phytoplankton competition among toxic dinoflagellates (Karenia brevis), nitrogen fixing cyanophytes (Trichodesmium erythraeum), large siliceous phytoplankton (diatoms), and small non-siliceous phytoplankton (microflagellates) explored the sequence of events required to support the observed red tide from August to December 2001. The ecological model contained 24 state variables within five submodels: circulation, atmospheric (iron deposition), bio-optics, pelagic (phytoplankton, nutrients, bacteria, zooplankton, and fish), and benthic (nutrient regeneration). The 2001 model results reaffirmed that diazotrophs are the basis for initiation of red tides of K. brevis on the WFS. A combination of selective grazing pressure, iron fertilization, low molar nitrogen to phosphorus ratios, and eventual silica limitation of fast-growing diatoms set the stage for dominance of nitrogen fixers. "New" nitrogen was made available for subsequent blooms of K. brevis through the release of ammonium and urea during nitrogen fixation, as well as during cell lysis, by the Trichodesmium population. Once K. brevis biomass reached ichthyotoxic levels, rapid decay of subsequent fish kills supplied additional organic nutrients for utilization by these opportunistic toxic algae. Both nutrient vectors represented organic non-siliceous sources of nitrogen and phosphorus, further exacerbating silica limitation of the diatom population. The model reproduced this spring transition from a simple estuarine-driven, diatom-based food chain to a complex summer-fall system of Trichodesmium and toxic dinoflagellates. While the model was able to replicate the initiation and maintenance of the 2001 red tide, bloom termination was not captured by this 1-D form on the WFS. Here, horizontal advection and perhaps cell lysis loss terms might play a significant role, to be

  11. System for the continuous generation of phosphorous aerosols from Red Phosphorus-Butyl Rubber. Final report

    SciTech Connect

    Holmberg, R.W.; Moneyhun, J.H.; Gayle, T.M.

    1985-06-01

    A system for the continuous generation of phosphoric acid aerosols from burning Red Phosphorus-Butyl Rubber (RPBR) is described. The system is primarily intended for inhalation toxicology experiments using high aerosol concentrations (ca. 0.3 to 3 g/m/sup 3/), but is adaptable to other studies where a time independent concentration of the aerosol is desired in a flowing system. The RPBR formulation is softened by addition of a small amount of hexane and extruded at a controlled rate at high pressure through an orifice. A precision hydraulic extrusion system using a micrometer adjustable high pressure hydraulic pump has been developed to control the extrusion rate. The emerging filament is ignited and burned in a flowing air stream for delivery to chambers. In addition to the extrusion-combustion system for aerosol generation, devices for recovering the spent aerosol and for monitoring its concentration are described. 2 refs., 18 figs.

  12. Modified MODIS fluorescence line height data product to improve image interpretation for red tide monitoring in the eastern Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Hu, Chuanmin; Feng, Lian

    2017-01-01

    Several satellite-based methods have been used to detect and trace Karenia brevis red tide blooms in the eastern Gulf of Mexico. Some require data statistics and multiple data products while others use a single data product. Of these, the MODIS normalized fluorescence line height (nFLH) has shown its advantage of detecting blooms in waters rich in colored dissolved organic matter, thus having been used routinely to assess bloom conditions by the Florida Fish and Wildlife Conservation Commission (FWC), the official state agency of Florida responsible for red tide monitoring and mitigation. However, elevated sediment concentrations in the water column due to wind storms can also result in high nFLH values, leading to false-positive bloom interpretation. Here, a modified nFLH data product is developed to minimize such impacts through empirical adjustments of the nFLH values using MODIS-derived remote sensing reflectance in the green band at 547 nm. The new product is termed as an algal bloom index (ABI), which has shown improved performance over the original nFLH in both retrospective evaluation statistics and near real-time applications. The ABI product has been made available in near real-time through a Web portal and has been used by the FWC on a routine basis to guide field sampling efforts and prepare for red tide bulletins distributed to many user groups.

  13. A red tide of Alexandrium fundyense in the Gulf of Maine

    NASA Astrophysics Data System (ADS)

    McGillicuddy, D. J.; Brosnahan, M. L.; Couture, D. A.; He, R.; Keafer, B. A.; Manning, J. P.; Martin, J. L.; Pilskaln, C. H.; Townsend, D. W.; Anderson, D. M.

    2014-05-01

    In early July 2009, an unusually high concentration of the toxic dinoflagellate Alexandrium fundyense occurred in the western Gulf of Maine, causing surface waters to appear reddish brown to the human eye. The discolored water appeared to be the southern terminus of a large-scale event that caused shellfish toxicity along the entire coast of Maine to the Canadian border. Rapid-response shipboard sampling efforts together with satellite data suggest the water discoloration in the western Gulf of Maine was a highly ephemeral feature of less than two weeks in duration. Flow cytometric analysis of surface samples from the red water indicated the population was undergoing sexual reproduction. Cyst fluxes downstream of the discolored water were the highest ever measured in the Gulf of Maine, and a large deposit of new cysts was observed that fall. Although the mechanisms causing this event remain unknown, its timing coincided with an anomalous period of downwelling-favorable winds that could have played a role in aggregating upward-swimming cells. Regardless of the underlying causes, this event highlights the importance of short-term episodic phenomena on regional population dynamics of A. fundyense.

  14. A red tide of Alexandrium fundyense in the Gulf of Maine

    PubMed Central

    McGillicuddy, D.J.; Brosnahan, M.L.; Couture, D.A.; He, R.; Keafer, B.A.; Manning, J.P.; Martin, J.L.; Pilskaln, C.H.; Townsend, D.W.; Anderson, D.M.

    2013-01-01

    In early July 2009, an unusually high concentration of the toxic dinoflagellate Alexandrium fundyense occurred in the western Gulf of Maine, causing surface waters to appear reddish brown to the human eye. The discolored water appeared to be the southern terminus of a large-scale event that caused shellfish toxicity along the entire coast of Maine to the Canadian border. Rapid-response shipboard sampling efforts together with satellite data suggest the water discoloration in the western Gulf of Maine was a highly ephemeral feature of less than two weeks in duration. Flow cytometric analysis of surface samples from the red water indicated the population was undergoing sexual reproduction. Cyst fluxes downstream of the discolored water were the highest ever measured in the Gulf of Maine, and a large deposit of new cysts was observed that fall. Although the mechanisms causing this event remain unknown, its timing coincided with an anomalous period of downwelling-favorable winds that could have played a role in aggregating upward-swimming cells. Regardless of the underlying causes, this event highlights the importance of short-term episodic phenomena on regional population dynamics of A. fundyense. PMID:25170191

  15. A red tide of Alexandrium fundyense in the Gulf of Maine.

    PubMed

    McGillicuddy, D J; Brosnahan, M L; Couture, D A; He, R; Keafer, B A; Manning, J P; Martin, J L; Pilskaln, C H; Townsend, D W; Anderson, D M

    2014-05-01

    In early July 2009, an unusually high concentration of the toxic dinoflagellate Alexandrium fundyense occurred in the western Gulf of Maine, causing surface waters to appear reddish brown to the human eye. The discolored water appeared to be the southern terminus of a large-scale event that caused shellfish toxicity along the entire coast of Maine to the Canadian border. Rapid-response shipboard sampling efforts together with satellite data suggest the water discoloration in the western Gulf of Maine was a highly ephemeral feature of less than two weeks in duration. Flow cytometric analysis of surface samples from the red water indicated the population was undergoing sexual reproduction. Cyst fluxes downstream of the discolored water were the highest ever measured in the Gulf of Maine, and a large deposit of new cysts was observed that fall. Although the mechanisms causing this event remain unknown, its timing coincided with an anomalous period of downwelling-favorable winds that could have played a role in aggregating upward-swimming cells. Regardless of the underlying causes, this event highlights the importance of short-term episodic phenomena on regional population dynamics of A. fundyense.

  16. New details from the complete life cycle of the red-tide dinoflagellate Noctiluca scintillans (Ehrenberg) McCartney.

    PubMed

    Fukuda, Yasuhiro; Endoh, Hiroshi

    2006-09-01

    Noctilucid protozoans are among the dinoflagellates that cause red tides. Sexual reproduction may occur in this group, as they sometimes undergo gametogenesis. However, the life cycle, in particular the developmental process after gamete fusion, has not been fully elucidated. We have been able to maintain clonal cultures of Noctiluca scintillans throughout the whole life cycle and have revealed new details of various stages. In trophont populations, a small fraction of cells spontaneously transform into gametogenic cells, which undergo two successive nuclear divisions, without cellular division, probably corresponding to meiosis. The products of nuclear division migrate to the cell surface with a small amount of cytoplasm, and there further synchronously divide 6-8 times, during which the division products are connected by thin cytoplasmic bridges. Thus, numerous gametes with a semi-spindle body shape are released from the mother cell ghost. They retain two flagella that differ in length and motion, as is typical of dinoflagellates. The presence of longitudinal and transverse grooves indicates that dinoflagellate-like characteristics are conserved in the gametes, although they are not present in the specialized trophonts. Zygotes with four flagella result from the fusion of two isogametes. The zygotes change shape from spindle to spherical, with a reduction in flagellar number. The developing cell acquires a tentacle and crust, similar to large trophonts, and begins to develop a cytoplasmic network, thus completing the transformation into a miniscule trophont. These early trophonts grow to maturity as cell size increases. Our observations of the life cycle of N. scintillans may provide clues for understanding the evolutionary origin of noctilucae.

  17. Aerosols, Lidar and IR Imaging During Duck and RED

    DTIC Science & Technology

    2001-09-30

    continued in connection with the analysis of transmission measurements over Monterey bay (22 km) and San Diego Bay (7 and 15 km). The results from the...to be improved. 3 As discussed in the FY00 report, during EOPACE experiments in 1996 and 1997 transmission was measured across San Diego Bay ...collected at mid-path by Professor Davidson from NPS ( Monterey ). TNO-FEL also measured aerosol particle size distributions at the end of the 15 km

  18. Isotopic evidence for dead fish maintenance of Florida red tides, with implications for coastal fisheries over both source regions of the West Florida shelf and within downstream waters of the South Atlantic Bight

    NASA Astrophysics Data System (ADS)

    Walsh, J. J.; Weisberg, R. H.; Lenes, J. M.; Chen, F. R.; Dieterle, D. A.; Zheng, L.; Carder, K. L.; Vargo, G. A.; Havens, J. A.; Peebles, E.; Hollander, D. J.; He, R.; Heil, C. A.; Mahmoudi, B.; Landsberg, J. H.

    2009-01-01

    Toxic Florida red tides of the dinoflagellate Kareniabrevis have downstream consequences of 500-1000 km spatial extent. Fish stocks, shellfish beds, and harmful algal blooms of similar species occupy the same continental shelf waters of the southeastern United States, amounting to economic losses of more than 25 million dollars in some years. Under the aegis of the Center for Prediction of Red tides, we are now developing coupled biophysical models of the conditions that lead to red tides and impacted coastal fisheries, from the Florida Panhandle to Cape Hatteras. Here, a nitrogen isotope budget of the coastal food web of the West Florida shelf (WFS) and the downstream South Atlantic Bight (SAB) reaffirms that diazotrophs are the initial nutrient source for onset of red tides and now identifies clupeid fish as the major recycled nutrient source for their maintenance. The recent isotope budget of WFS and SAB coastal waters during 1998-2001 indicates that since prehistoric times of Timacua Indian settlements along the Georgia coast during 1075, ∼50% of the nutrients required for large red tides of >1 μg chl l -1 of K.brevis have been derived from nitrogen-fixers, with the other half from decomposing dead sardines and herrings. During 2001, >90% of the harvest of WFS clupeids was by large ichthyotoxic red tides of >10 μg chl l -1 of K.brevis, rather than by fishermen. After onset of the usual red tides in summer of 2006 and 2007, the simulated subsequent fall exports of Florida red tides in September 2007 to North Carolina shelf waters replicate observations of just ∼1 μg chl l -1 on the WFS that year. In contrast, the earlier red tides of >10 μg chl l -1 left behind off West Florida during 2006, with less physical export, are instead 10-fold larger than those of 2007. Earlier, 55 fish kills were associated with these coastal red tides during September 2006, between Tampa and Naples. Yet, only six fish kills were reported there in September 2007. With little

  19. Records of bulk organic matter and plant pigments in sediment of the "red-tide zone" adjacent to the Changjiang River estuary

    NASA Astrophysics Data System (ADS)

    Kang, Zhenjun; Yu, Rencheng; Kong, Fanzhou; Wang, Yunfeng; Gao, Yan; Chen, Jianhua; Guo, Wei; Zhou, Mingjiang

    2016-09-01

    Cultural eutrophication caused by nutrient over-enrichment in coastal waters will lead to a cascading set of ecosystem changes and deleterious ecological consequences, such as harmful algal blooms (HABs) and hypoxia. During the past two decades since the late 1990s, recurrent large-scale HABs (red tides) and an extensive hypoxic zone have been reported in the coastal waters adjacent to the Changjiang River estuary. To retrieve the history of eutrophication and its associated ecosystem changes, a sediment core was collected from the "red-tide zone" adjacent to the Changjiang River estuary. The core was dated using the 210Pb radioisotope and examined for multiple proxies, including organic carbon (OC), total nitrogen (TN), stable isotopes of C and N, and plant pigments. An apparent up-core increase of OC content was observed after the 1970s, accompanied by a rapid increase of TN. The concurrent enrichment of δ13C and increase of the C/N ratio suggested the accumulation of organic matter derived from marine primary production during this stage. The accumulation of OC after the 1970s well reflected the significant increase of primary production in the red-tide zone and probably the intensification of hypoxia as well. Plant pigments, including chlorophyll a, β-carotene, and diatoxanthin, showed similar patterns of variation to OC throughout the core, which further confirmed the important contribution of microalgae, particularly diatoms, to the deposited organic matter. Based on the variant profiles of the pigments representative of different microalgal groups, the potential changes of the phytoplankton community since the 1970s were discussed.

  20. Submarine groundwater discharge and nutrient loadings in Tolo Harbor, Hong Kong using multiple geotracer-based models, and their implications of red tide outbreaks.

    PubMed

    Luo, Xin; Jiao, Jiu Jimmy

    2016-10-01

    Multiple tracers, including radium quartet, (222)Rn and silica are used to quantify submarine groundwater discharge (SGD) into Tolo Harbor, Hong Kong in 2005 and 2011. Five geotracer models based on the end member model of (228)Ra and salinity and mass balance models of (226)Ra, (228)Ra, (222)Rn, and silica were established and all the models lead to an estimate of the SGD rate of the same order of magnitude. In 2005 and 2011, respectively, the averaged SGD based on these models is estimated to be ≈ 5.42 cm d(-1) and ≈2.66 cm d(-1), the SGD derived DIN loadings to be 3.5 × 10(5) mol d(-1) and 1.5 × 10(5) mol d(-1), and DIP loadings to be 6.2 × 10(3) mol d(-1) and 1.1 × 10(3) mol d(-1). Groundwater borne nutrients are 1-2 orders of magnitude larger than other nutrient sources and the interannual variation of nutrient concentration in the embayment is more influenced by the SGD derived loadings. Annual DIP concentrations in the harbor water is positively correlated with the precipitation and annual mean tidal range, and negatively correlated with evapotranspiration from 2000 to 2013. Climatologically driven SGD variability alters the SGD derived DIP loadings in this phosphate limited environment and may be the causative factor of interannual variability of red tide outbreaks from 2000 to 2013. Finally, a conceptual model is proposed to characterize the response of red tide outbreaks to climatological factors linked by SGD. The findings from this study shed light on the prediction of red tide outbreaks and coastal management of Tolo Harbor and similar coastal embayments elsewhere.

  1. Sublethal red tide toxin exposure in free-ranging manatees (Trichechus manatus) affects the immune system through reduced lymphocyte proliferation responses, inflammation, and oxidative stress.

    PubMed

    Walsh, Catherine J; Butawan, Matthew; Yordy, Jennifer; Ball, Ray; Flewelling, Leanne; de Wit, Martine; Bonde, Robert K

    2015-04-01

    The health of many Florida manatees (Trichechus manatus latirostris) is adversely affected by exposure to blooms of the toxic dinoflagellate, Karenia brevis. K. brevis blooms are common in manatee habitats of Florida's southwestern coast and produce a group of cyclic polyether toxins collectively referred to as red tide toxins, or brevetoxins. Although a large number of manatees exposed to significant levels of red tide toxins die, several manatees are rescued from sublethal exposure and are successfully treated and returned to the wild. Sublethal brevetoxin exposure may potentially impact the manatee immune system. Lymphocyte proliferative responses and a suite of immune function parameters in the plasma were used to evaluate effects of brevetoxin exposure on health of manatees rescued from natural exposure to red tide toxins in their habitat. Blood samples were collected from rescued manatees at Lowry Park Zoo in Tampa, FL and from healthy, unexposed manatees in Crystal River, FL. Peripheral blood leukocytes (PBL) isolated from whole blood were stimulated with T-cell mitogens, ConA and PHA. A suite of plasma parameters, including plasma protein electrophoresis profiles, lysozyme activity, superoxide dismutase (SOD) activity, and reactive oxygen/nitrogen (ROS/RNS) species, was also used to assess manatee health. Significant decreases (p<0.05) in lymphocyte proliferation were observed in ConA and PHA stimulated lymphocytes from rescued animals compared to non-exposed animals. Significant correlations were observed between oxidative stress markers (SOD, ROS/RNS) and plasma brevetoxin concentrations. Sublethal exposure to brevetoxins in the wild impacts some immune function components, and thus, overall health, in the Florida manatee.

  2. Quantifying the climatological cloud-free direct radiative forcing of aerosol over the Red Sea

    NASA Astrophysics Data System (ADS)

    Brindley, Helen; Osipov, Serega; Bantges, Richard; Smirnov, Alexander; Banks, Jamie; Levy, Robert; Prakash, P.-Jish; Stenchikov, Georgiy

    2015-04-01

    A combination of ground-based and satellite observations are used, in conjunction with column radiative transfer modelling, to assess the climatological aerosol loading and quantify its corresponding cloud-free direct radiative forcing (DRF) over the Red Sea. While there have been campaigns designed to probe aerosol-climate interactions over much of the world, relatively little attention has been paid to this region. Because of the remoteness of the area, satellite retrievals provide a crucial tool for assessing aerosol loading over the Sea. However, agreement between aerosol properties inferred from measurements from different instruments, and even in some cases from the same measurements using different retrieval algorithms can be poor, particularly in the case of mineral dust. Ground based measurements which can be used to evaluate retrievals are thus highly desirable. Here we take advantage of ship-based sun-photometer micro-tops observations gathered from a series of cruises which took place across the Red Sea during 2011 and 2013. To our knowledge these data represent the first set of detailed aerosol measurements from the Sea. They thus provide a unique opportunity to assess the performance of satellite retrieval algorithms in this region. Initially two aerosol optical depth (AOD) retrieval algorithms developed for the MODerate Resolution Imaging Spectroradiometer (MODIS) and Spinning Enhanced Visible and InfraRed Imager (SEVIRI) instruments are evaluated via comparison with the co-located cruise observations. These show excellent agreement, with correlations typically better than 0.9 and very small root-mean-square and bias differences. Calculations of radiative fluxes and DRF along one of the cruises using the observed aerosol and meteorological conditions also show good agreement with co-located estimates from the Geostationary Earth Radiation Budget (GERB) instrument if the aerosol asymmetry parameter is adjusted to account for the presence of large

  3. Investigation the Behavior of Modis Ocean Color Products Under the 2008 Red Tide in the Eastern Persian Gulf

    NASA Astrophysics Data System (ADS)

    Ghanea, M.; Moradi, M.; Kabiri, K.

    2015-12-01

    Biophysical properties of water undergo serious variations under red tide (RT) outbreak. During RT conditions, algal blooms spread out in the estuarine, marine and fresh waters due to different triggering factors such as nutrient loading, marine currents, and monsoonal winds. The Persian Gulf (PG) was a talent region subjected to different RTs in recent decade. A massive RT started from the Strait of Hormuz in October 2008 and extended towards the northern parts of the PG covering more than 1200 km of coastlines. The bloom of microorganism C. Polykrikoides was the main specie that generated large fish mortalities, and hampered marine industries, and water desalination appliances. Ocean color satellite data have many advantages to monitor and alarm RT occurrences, such as wide and continuous extent, short time of imagery, high accessibility, and appropriate estimation of ocean color parameters. Since 1999, MODerate Resolution Imaging Spectroradiometer (MODIS) satellite sensor has estimated satellite derived chlorophyll-a (Chl-a), normalized fluorescence line height (nFLH), and diffuse attenuation coefficient at 490nm (kd490). It provides a capability to study the behavior of these parameters during RT and normal conditions. This study monitors variations in satellite derived Chl-a, nFLH, and kd490 under both RT and normal conditions of the PG between 2002 and 2008. Up to now, daily and monthly variations in these products were no synchronously investigated under RT conditions in the PG. In doing so, the MODIS L1B products were provided from NASA data archive. They were corrected for Rayleigh scattering and gaseous absorption, and atmospheric interference in turbid coastal waters, and then converted to level 2 data. In addition, Enhanced Red Green Blue (ERGB) image was used to illustrate better water variations. ERGB image was built with three normalized leaving water radiance between 443 to 560nm. All the above data processes were applied by SeaDAS 7 software

  4. Isolation, purification, and identification of antialgal substances in green alga Ulva prolifera for antialgal activity against the common harmful red tide microalgae.

    PubMed

    Sun, Ying-ying; Wang, Hui; Guo, Gan-lin; Pu, Yin-fang; Yan, Bin-lun; Wang, Chang-hai

    2016-01-01

    Ten compounds (1~10) were successfully isolated from green algae Ulva prolifera through the combination of silica gel column chromatography, Sephadex LH-20 column chromatography and repeated preparative thin-layer chromatography. These ten compounds showed antialgal activity against red tide microalgae. Among them, compounds 3, 6, and 7 showed stronger antialgal activity against red tide microalgae. Furthermore, their structure was identified on the basis of spectroscopic data. There are three glycoglycerolipids: 1-O-octadecanoic acid-3-O-β-D-galactopyranosyl glycerol (2), 1-O-palmitoyl-3-O-β-D-galactopyranosyl glycerol (4), and 1-O-palmitoyl-2-O-oleoyl-3-O-β-D-galactopyranosyl glycerol (5); two monoglycerides: glycerol monopalmitate (1), 9-hexadecenoic acid, 2,3-dihydroxypropyl ester (3); two terpenoids: loliolide (6) and lsololiolide (7); one lipid-soluble pigments: zeaxanthin (8); one sterol: cholest-5-en-3-ol (9); and one alkaloid: pyrrolopiperazine-2,5-dione (10). These compounds were isolated from U. prolifera for the first time, and compounds 2, 3, 5, and 8 were isolated from marine macroalgae for the first time.

  5. Earth tides

    SciTech Connect

    Harrison, J.C.

    1984-01-01

    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.

  6. Satellite retrievals of dust aerosol over the Red Sea and the Persian Gulf (2005-2015)

    NASA Astrophysics Data System (ADS)

    Banks, Jamie R.; Brindley, Helen E.; Stenchikov, Georgiy; Schepanski, Kerstin

    2017-03-01

    The inter-annual variability of the dust aerosol presence over the Red Sea and the Persian Gulf is analysed over the period 2005-2015. Particular attention is paid to the variation in loading across the Red Sea, which has previously been shown to have a strong, seasonally dependent latitudinal gradient. Over the 11 years considered, the July mean 630 nm aerosol optical depth (AOD) derived from the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) varies between 0.48 and 1.45 in the southern half of the Red Sea. In the north, the equivalent variation is between 0.22 and 0.66. The temporal and spatial pattern of variability captured by SEVIRI is also seen in AOD retrievals from the MODerate Imaging Spectroradiometer (MODIS), but there is a systematic offset between the two records. Comparisons of both sets of retrievals with ship- and land-based AERONET measurements show a high degree of correlation with biases of < 0.08. However, these comparisons typically only sample relatively low aerosol loadings. When both records are stratified by AOD retrievals from the Multi-angle Imaging SpectroRadiometer (MISR), opposing behaviour is revealed at high MISR AODs ( > 1), with offsets of +0.19 for MODIS and -0.06 for SEVIRI. Similar behaviour is also seen over the Persian Gulf. Analysis of the scattering angles at which retrievals from the SEVIRI and MODIS measurements are typically performed in these regions suggests that assumptions concerning particle sphericity may be responsible for the differences seen.

  7. System for the continuous generation of phosphorus aerosol from red phosphorus - butyl rubber

    SciTech Connect

    Holmberg, R.W.; Moneyhun, J.H.

    1982-01-01

    Laboratory studies of Army smokes and obscurants often require that they be produced at known and uniform concentrations for a long period of time, and with properties that are comparable to those produced by the obscurant system in the field. In support of the toxicology program of the US Army Medical and Bioengineering Research and Development Laboratory, Fort Detrick, MD, we describe an extrusion-combustion generator that generates the phosphoric acid aerosol from a red phosphorus-butyl rubber (RPBR) formulation such as is deployed in a L8Al smoke grenade. The generator has been designed to produce aerosols of concentration from 0.25 to 5 g/m/sup 3/ in a one cubic meter chamber with an air throughput of 400 l/m, but can easily be adapted to other conditions. The generator design is based on the property that RPBR, suitably softened, can be extruded through a small orifice. The extruding filament burns, and the aerosol is produced, at a rate determined by the velocity of the filament emergence. In our implementation, the RPBR is softened by vapor phase absorption of hexane to 4% by weight. The material is compressed to form a cylindrical billet (1/2 inch diameter) and loaded into the extrusion cylinder for extrusion through a 2 mm orifice. A conventional hydraulic ram is used to provide the extrusion pressure. Hydraulic fluid is fed to it from a precision, high pressure metering pump. This fluid flow determines the rate at which the RPBR emerges from the dye. The filament is electrically ignited to burn in the air stream. It is sheathed in nitrogen gas as it emerges from the dye to prevent back combustion and to define the burning area. The aerosol concentration is monitored continuously using light scattering particle detectors whose response is linear with concentration.

  8. Characterization of Marine Aerosol for Assessment of Human Exposure to Brevetoxins

    PubMed Central

    Cheng, Yung Sung; Zhou, Yue; Irvin, Clinton M.; Pierce, Richard H.; Naar, Jerome; Backer, Lorraine C.; Fleming, Lora E.; Kirkpatrick, Barbara; Baden, Dan G.

    2005-01-01

    Red tides in the Gulf of Mexico are commonly formed by the fish-killing dinoflagellate Karenia brevis, which produces nine potent polyether brevetoxins (PbTxs). Brevetoxins can be transferred from water to air in wind-powered white-capped waves. Inhalation exposure to marine aerosol containing brevetoxins causes respiratory symptoms. We describe detailed characterization of aerosols during an epidemiologic study of occupational exposure to Florida red tide aerosol in terms of its concentration, toxin profile, and particle size distribution. This information is essential in understanding its source, assessing exposure to people, and estimating dose of inhaled aerosols. Environmental sampling confirmed the presence of brevetoxins in water and air during a red tide exposure period (September 2001) and lack of significant toxin levels in the water and air during an unexposed period May 2002). Water samples collected during a red tide bloom in 2001 showed moderate-to-high concentrations of K. brevis cells and PbTxs. The daily mean PbTx concentration in water samples ranged from 8 to 28 μg/L from 7 to 11 September 2001; the daily mean PbTx concentration in air samples ranged from 1.3 to 27 ng/m3. The daily aerosol concentration on the beach can be related to PbTx concentration in water, wind speed, and wind direction. Personal samples confirmed human exposure to red tide aerosols. The particle size distribution showed a mean aerodynamic diameter in the size range of 6–12 μm, with deposits mainly in the upper airways. The deposition pattern correlated with the observed increase of upper airway symptoms in healthy lifeguards during the exposure periods. PMID:15866777

  9. A red tide alga grown under ocean acidification upregulates its tolerance to lower pH by increasing its photophysiological functions

    NASA Astrophysics Data System (ADS)

    Chen, S.; Beardall, J.; Gao, K.

    2014-09-01

    Phaeocystis globosa, a red tide alga, often forms blooms in or adjacent to coastal waters and experiences changes in pH and seawater carbonate chemistry caused by either diel/periodic fluctuation in biological activity, human activity or, in the longer term, ocean acidification due to atmospheric CO2 rise. We examined the photosynthetic physiology of this species while growing it under different pH levels induced by CO2 enrichment and investigated its acclimation to carbonate chemistry changes under different light levels. Short-term exposure to reduced pHnbs (7.70) decreased the alga's photosynthesis and light use efficiency. However, acclimation to the reduced pH level for 1-19 generations led to recovered photosynthetic activity, being equivalent to that of cells grown under pH 8.07 (control), though such acclimation required a different time span (number of generations) under different light regimes. The low-pH-grown cells increased their contents of chlorophyll and carotenoids with prolonged acclimation to the acidification, with increased photosynthetic quantum yield and decreased non-photochemical quenching. The specific growth rate of the low-pH-grown cells also increased to emulate that grown under the ambient pH level. This study clearly shows that {Phaeocystis globosa} is able to acclimate to seawater acidification by increasing its energy capture and decreasing its non-photochemical energy loss.

  10. A red tide alga grown under ocean acidification up-regulates its tolerance to lower pH by increasing its photophysiological functions

    NASA Astrophysics Data System (ADS)

    Chen, S.-W.; Beardall, J.; Gao, K.-S.

    2014-05-01

    Phaeocystis globosa, a red tide alga, often forms blooms in or adjacent to coastal waters and experiences changes of pH and seawater carbonate chemistry caused by either diel/periodic fluctuation in biological activity, human activity or, in the longer term, ocean acidification due to atmospheric CO2 rise. We examined the photosynthetic physiology of this species while growing it under different pH levels induced by CO2 enrichment and investigated its acclimation to carbonate chemistry changes under different light levels. Short-term exposure to reduced pHnbs (7.70) decreased the alga's photosynthesis and light use efficiency. However, acclimation to the reduced pH level for 1-19 generations led to recovered photosynthetic activity, being equivalent to that of cells grown under pH 8.07 (control), though such acclimation required a different time span (number of generations) under different light regimes. The low-pH grown cells increased their contents of chlorophyll and carotenoids with prolonged acclimation to the acidification, with increased photosynthetic quantum yield and decreased non-photochemical quenching. The specific growth rate of the low-pH grown cells also increased to emulate that grown under the ambient pH level. This study clearly shows that Phaeocystis globosa is able to acclimate to seawater acidification by increasing its energy capture and decreasing its non-photochemcial energy loss.

  11. Allelopathic inhibition of photosynthesis in the red tide-causing marine alga, Scrippsiella trochoidea (Pyrrophyta), by the dried macroalga, Gracilaria lemaneiformis (Rhodophyta)

    NASA Astrophysics Data System (ADS)

    Ye, Changpeng; Liao, Heping; Yang, Yufeng

    2014-07-01

    The red tide-causing microalga, Scrippsiella trochoidea was co-cultured with different quantities of dried macroalga Gracilaria lemaneiformis under laboratory conditions, to characterize the allelopathic inhibition effect of the seaweed on photosynthesis of the microalga. Photosynthetic oxygen evolution was measured, and chlorophyll a (Chl a) fluorescence transient O-J-I-P (O, J, I and P point in primary photochemistry reaction curve in photosystem II) curves associated with its specific parameters were determined. A concentration-dependent inhibition of S. trochoidea was observed when the dried seaweed was added. The rate of light-saturated maximum photosynthetic oxygen evolution (Pmax) was markedly decreased, and the O-J-I-P curve coupled with its specific parameters was reduced. The inhibitory effects of the macroalga on the microalga, according to the JIP-test (the relative fluorescence analysis based on O-J-I-P curve) and the activity of oxygen evolution, include a decrease in the number of active reaction centers, the blocking-up of the electron transport chain, and the damage to the oxygen-evolving complex. This study suggests that dried G. lemaneiformis is effective in inhibiting photosynthesis of S. trochoidea, and could thus be a potential candidate for mitigating S. trochoidea blooms.

  12. Effects of three macroalgae, Ulva linza (Chlorophyta), Corallina pilulifera (Rhodophyta) and Sargassum thunbergii (Phaeophyta) on the growth of the red tide microalga Prorocentrum donghaiense under laboratory conditions

    NASA Astrophysics Data System (ADS)

    Wang, Renjun; Xiao, Hui; Wang, You; Zhou, Wenli; Tang, Xuexi

    2007-10-01

    Allelopathic effects of several concentrations of fresh tissue and dry powder of three macroalgae, Ulva linza, Corallina pilulifera and Sargassum thunbergii, on the red tide microalga Prorocentrum donghaiense were evaluated in microcosms. Preliminary studies on the algicidal effects of one aqueous and four organic solvent extracts from the macroalgae on the microalga were carried out to confirm the existence of allelochemicals in the tissues of the macroalgae. The effects of macroalgal culture medium filtrate on P. donghaiense were investigated using initial or semi-continuous filtrate addition. Furthermore, the potential effects of the microalga on these three macroalgae were also tested. The results of the microcosm assay showed that the growth of P. donghaiense was strongly inhibited by using fresh tissues and dry powder of the three macroalgae. Both aqueous and methanol extracts of the macroalgae had strong growth inhibitory effects on P. donghaiense, while the other three organic solvent extracts (acetone, ether and chloroform) had no apparent effect on its growth; this suggested that the allelochemicals from these three macroalga had relatively high polarities. The three macroalgal culture medium filtrates exhibited apparent growth inhibitory effect on the microalgae under initial or semi-continuous addition, which suggested that the cells of P. donghaiense are sensitive to the allelochemicals. In contrast, P. donghaiense had no apparent effect on the growth of the macroalgae in coexistence experiment.

  13. Potential effects of brevetoxins and toxic elements on various health variables in Kemp's ridley (Lepidochelys kempii) and green (Chelonia mydas) sea turtles after a red tide bloom event.

    PubMed

    Perrault, Justin R; Stacy, Nicole I; Lehner, Andreas F; Mott, Cody R; Hirsch, Sarah; Gorham, Jonathan C; Buchweitz, John P; Bresette, Michael J; Walsh, Catherine J

    2017-12-15

    Natural biotoxins and anthropogenic toxicants pose a significant risk to sea turtle health. Documented effects of contaminants include potential disease progression and adverse impacts on development, immune function, and survival in these imperiled species. The shallow seagrass habitats of Florida's northwest coast (Big Bend) serve as an important developmental habitat for Kemp's ridley (Lepidochelys kempii) and green (Chelonia mydas) sea turtles; however, few studies have been conducted in this area. Our objectives were (1) to evaluate plasma analytes (mass, minimum straight carapace length, body condition index [BCI], fibropapilloma tumor score, lysozyme, superoxide dismutase, reactive oxygen/nitrogen species, plasma protein electrophoresis, cholesterol, and total solids) in Kemp's ridleys and green turtles and their correlation to brevetoxins that were released from a red tide bloom event from July-October 2014 in the Gulf of Mexico near Florida's Big Bend, and (2) to analyze red blood cells in Kemp's ridleys and green turtles for toxic elements (arsenic, cadmium, lead, mercury, selenium, thallium) with correlation to the measured plasma analytes. Positive correlations were observed between brevetoxins and α2-globulins in Kemp's ridleys and α2- and γ-globulins in green turtles, indicating potential immunostimulation. Arsenic, cadmium, and lead positively correlated with superoxide dismutase in Kemp's ridleys, suggesting oxidative stress. Lead and mercury in green turtles negatively correlated with BCI, while mercury positively correlated with total tumor score of green turtles afflicted with fibropapillomatosis, suggesting a possible association with mercury and increased tumor growth. The total tumor score of green turtles positively correlated with total protein, total globulins, α2-globulins, and γ-globulins, further suggesting inflammation and immunomodulation as a result of fibropapillomatosis. Lastly, brevetoxin concentrations were positively related

  14. Molecular Quantification of the Florida Red Tide Dinoflagellate and the Development of Low Cost, Volunteer-attended Handheld Sensor Networks

    NASA Astrophysics Data System (ADS)

    Nieuwkerk, D.; Ulrich, R. M.; Paul, J. H.; Hubbard, K.; Kirkpatrick, B. A.; Fanara, T. A.; Bruzek, S.; Hoeglund, A.

    2016-02-01

    Harmful algal blooms of the dinoflagellate Karenia brevis can cause massive fish-kills and marine mammal mortalities, as well as impact human health via the consumption of brevetoxin-contaminated shellfish and the inhalation of aerosolized toxins. There is a strong effort to predict human health impacts by monitoring the bloom stages of K. brevis, and to prevent health impacts by closing shellfish beds when K. brevis cell concentrations reach toxic levels. The current standard method for quantifying K. brevis is by microscopic enumeration, which requires taxonomic expertise to discern K. brevis cells from other Karenia species as well as a long turnover time to generate data, which limits the number of water samples that can be processed. This EPA-funded study compared a variety of technologies against the current standard (microscopic counts) to quantify the number of K. brevis cells per liter in the water column. Results of this study showed a strong correlation between Real Time Nucleic Acid Sequence-Based Amplification (RT-NASBA) and enumeration by microscopy performed by members of the Florida Fish and Wildlife Research Institute, who are responsible for such monitoring. We are adapting the bench-top RT-NASBA assay to the AmpliFire platform (a handheld sensor that can be used in the field), for point of need K. brevis detection. These handheld sensors will be used by a trained volunteer network and government agencies (FWC, NOAA, and Mote Marine Lab.) to quantify K. brevis cells in the water column of core Gulf of Mexico sites; the results from these sensors will be reported back to the GCOOS observation systems to provide real-time monitoring of K. brevis counts. The real-time information will allow agencies to better monitor fishery closures and predict human health impacts of harmful algal blooms, because a larger number of samples can be processed each week, as the NASBA process removes the rate-limiting step of microscope time.

  15. Kingdom of the Tides.

    ERIC Educational Resources Information Center

    Carter, Samuel, III

    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…

  16. Kingdom of the Tides.

    ERIC Educational Resources Information Center

    Carter, Samuel, III

    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…

  17. Quantifying the climatological cloud-free shortwave direct radiative forcing of mineral dust aerosol over the Red Sea

    NASA Astrophysics Data System (ADS)

    Stenchikov, G. L.; Brindley, H. E.; Osipov, S.; Bantges, R. J.; Smirnov, A.; Prakash, P. J.

    2014-12-01

    While there have been a number of campaigns designed to probe dust-climate interactions over much of the world, relatively little attention has been paid to the Red Sea. Because of the remoteness of the area, satellite retrievals provide a crucial tool for assessing aerosol loading over the Sea. However, agreement between aerosol properties inferred from measurements from different instruments, and even in some cases from the same measurements using different retrieval algorithms can be poor, particularly in the case of mineral dust. Ground based measurements, which can be used to evaluate retrievals, are thus highly desirable. Here we take advantage of ship-based hand-held sun-photometer (microtops) observations gathered within the framework of NASA Aerosol Maritime Network from a series of cruises, which took place across the Red Sea during 2011 and 2013. To our knowledge these data represent the first set of detailed aerosol measurements from the Sea. They thus provide a unique opportunity to assess the performance of satellite retrieval algorithms in this region. Here we used the microtops measurements to evaluate the performance of co-located satellite retrievals from the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) and the MODerate Imaging Spectrometer (MODIS). Both algorithms show good agreement with the ship-based measurements and with each other, although it appears that the MODIS cloud detection scheme in particular is rather conservative. The stand alone Rapid Radiative Transfer Model (RRTM) driven by reanalysis meteorological fields is used to estimate the cloud-free aerosol direct radiative effect at the surface and TOA along the ship tracks. The TOA effects are compared to co-located measurements from the Geostationary Earth Radiation Budget (GERB) instrument. Having evaluated both the quality of the retrievals and the ability of the model to capture the associated radiative effect, we will present a climatology of aerosol loading over the

  18. Satellite remote sensing of harmful algal blooms: A new multi-algorithm method for detecting the Florida Red Tide (Karenia brevis)

    PubMed Central

    Carvalho, Gustavo A.; Minnett, Peter J.; Fleming, Lora E.; Banzon, Viva F.; Baringer, Warner

    2010-01-01

    In a continuing effort to develop suitable methods for the surveillance of Harmful Algal Blooms (HABs) of Karenia brevis using satellite radiometers, a new multi-algorithm method was developed to explore whether improvements in the remote sensing detection of the Florida Red Tide was possible. A Hybrid Scheme was introduced that sequentially applies the optimized versions of two pre-existing satellite-based algorithms: an Empirical Approach (using water-leaving radiance as a function of chlorophyll concentration) and a Bio-optical Technique (using particulate backscatter along with chlorophyll concentration). The long-term evaluation of the new multi-algorithm method was performed using a multi-year MODIS dataset (2002 to 2006; during the boreal Summer-Fall periods – July to December) along the Central West Florida Shelf between 25.75°N and 28.25°N. Algorithm validation was done with in situ measurements of the abundances of K. brevis; cell counts ≥1.5×104 cells l−1 defined a detectable HAB. Encouraging statistical results were derived when either or both algorithms correctly flagged known samples. The majority of the valid match-ups were correctly identified (~80% of both HABs and non-blooming conditions) and few false negatives or false positives were produced (~20% of each). Additionally, most of the HAB-positive identifications in the satellite data were indeed HAB samples (positive predictive value: ~70%) and those classified as HAB-negative were almost all non-bloom cases (negative predictive value: ~86%). These results demonstrate an excellent detection capability, on average ~10% more accurate than the individual algorithms used separately. Thus, the new Hybrid Scheme could become a powerful tool for environmental monitoring of K. brevis blooms, with valuable consequences including leading to the more rapid and efficient use of ships to make in situ measurements of HABs. PMID:21037979

  19. An 11-year analysis of satellite retrievals of dust aerosol over the Red Sea and the Persian Gulf

    NASA Astrophysics Data System (ADS)

    Banks, Jamie; Brindley, Helen; Schepanski, Kerstin; Stenchikov, Georgiy

    2017-04-01

    As enclosed seas bordering two large desert regions, the Saharan and Arabian deserts, the maritime environments of the Red Sea and the Persian Gulf are heavily influenced by the presence of desert dust aerosol. The inter-annual variability of dust presence over the Red Sea is analysed and presented, with respect to the summer-time latitudinal gradient in dust loading, which is at a maximum in the far south of the Red Sea and at a minimum in the far north. Two satellite aerosol optical depth (AOD) products from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) and the MODerate resolution Imaging Spectroradiometer (MODIS) instruments are used to quantify this loading over the region. Over an eleven-year period from 2005-2015 the July mean SEVIRI AODs at 630 nm vary between 0.48 and 1.45 in the southern half of the Sea, while in the north this varies between 0.22 and 0.66. Inter-retrieval offsets are observed to occur at higher dust loadings, with pronounced positive MODIS-SEVIRI AOD offsets at AODs greater than 1, indicating substantial and systematic differences between the retrievals over the Red Sea at high dust loadings. These differences appear to be influenced in part by the differences in scattering angle range of the satellite measurements, implying that assumptions of particle shape introduce more substantial biases at the highest dust loadings.

  20. Malaria and Red Tide Chemistry

    NASA Astrophysics Data System (ADS)

    Heinhorst, Sabine; Cannon, Gordon

    1998-10-01

    The January 1st, 1998, issue of Nature (Vol. 391) presented us with the annual "Anniversaries" commentary (pp 13-16) which commemorates landmark scientific discoveries and puts them in a historical perspective. Pierre and Marie Curie discovered polonium and radium in 1898; Henry Cavendish measured gravity and determined the density of the earth for the first time in 1798; and Hildegard von Bingen was born in 1098.

  1. TideNet

    DTIC Science & Technology

    2014-10-27

    mapping tools to query sources of tide data in a desired geographic region of the U.S. and its territories. Users can select a tide data source...produce tables and figures, and prepare input files for numerical models used in USACE projects. TideNet can fetch tide data, including plots and...tables from the source, or process tide data downloaded from any source site to perform additional analyses. The home page of the TideNet map in

  2. Small particle aerosol inoculation of cowpox Brighton Red in rhesus monkeys results in a severe respiratory disease

    SciTech Connect

    Johnson, Reed F.; Hammoud, Dima A.; Lackemeyer, Matthew G.; Yellayi, Srikanth; Solomon, Jeffrey; Bohannon, Jordan K.; Janosko, Krisztina B.; Jett, Catherine; Cooper, Kurt; Blaney, Joseph E.; Jahrling, Peter B.

    2015-07-15

    Cowpox virus (CPXV) inoculation of nonhuman primates (NHPs) has been suggested as an alternate model for smallpox (Kramski et al., 2010, PLoS One, 5, e10412). Previously, we have demonstrated that intrabronchial inoculation of CPXV-Brighton Red (CPXV-BR) into cynomolgus monkeys resulted in a disease that shared many similarities to smallpox; however, severe respiratory tract disease was observed (Smith et al., 2011, J. Gen. Virol.). Here we describe the course of disease after small particle aerosol exposure of rhesus monkeys using computed tomography (CT) to monitor respiratory disease progression. Subjects developed a severe respiratory disease that was uniformly lethal at 5.7 log{sub 10} PFU of CPXV-BR. CT indicated changes in lung architecture that correlated with changes in peripheral blood monocytes and peripheral oxygen saturation. While the small particle aerosol inoculation route does not accurately mimic human smallpox, the data suggest that CT can be used as a tool to monitor real-time disease progression for evaluation of animal models for human diseases. - Highlights: • Small particle aerosol exposure of rhesus results in a severe respiratory disease. • CT findings correlated with peripheral oxygen saturation and monocyte increases. • Virus dissemination was limited and mainly confined to the respiratory tract. • CT provides insight into pathogenesis to aid development of animal models of disease.

  3. Europa Tide Movie

    NASA Technical Reports Server (NTRS)

    2007-01-01

    [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.

  4. Europa Tide Movie

    NASA Technical Reports Server (NTRS)

    2007-01-01

    [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.

  5. Lanthanides determination in red wine using ultrasound assisted extraction, flow injection, aerosol desolvation and ICP-MS.

    PubMed

    Bentlin, Fabrina R S; dos Santos, Clarissa M M; Flores, Erico M M; Pozebon, Dirce

    2012-01-13

    This paper deals with the determination of the fourteen naturally occurring elements of the lanthanide series in red wine. Ultrasound (US) was used for sample preparation prior lanthanides determination using ICP-MS. Flow injection (FI) and pneumatic nebulization/aerosol desolvation were used for nebulization of aliquots of 50 μL of sample and its subsequent transportation to plasma. Sample preparation procedures, matrix interference and time of sonication were evaluated. Better results for lanthanides in red wine were obtained by sonication with US probe for 90 s and sample 10-fold diluted. The limits of detection of La, Ce, Nd, Sm, Gd, Pr, Eu, Tb, Dy, Ho, Er, Tm, Lu and Yb were 6.57, 10.8, 9.97, 9.38, 2.71, 1.29, 1.22, 0.52, 2.35, 0.96, 2.30, 0.45, 0.24 and 1.35 ng L(-1), respectively. Red wines of different varieties from three countries of South America were discriminated according to the country of origin by means of multivariate analysis of lanthanides concentration. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Assessing effects of esfenvalerate aerosol applications on resident populations of Tribolium castaneum (Herbst), the red flour beetle, through direct and indirect sampling

    USDA-ARS?s Scientific Manuscript database

    Small-scale field sheds were infested with resident populations of the red flour beetle, Tribolium castaneum (Herbst), and either left untreated or treated every two or four weeks with an aerosol spray of esfenvalerate (Conquer ®). The sheds were infested by placing flour food patches underneath she...

  7. What Causes Tides?

    ERIC Educational Resources Information Center

    Donovan, Deborah

    2004-01-01

    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…

  8. What Causes Tides?

    ERIC Educational Resources Information Center

    Donovan, Deborah

    2004-01-01

    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…

  9. An assessment of the quality of aerosol retrievals over the Red Sea and evaluation of the climatological cloud-free dust direct radiative effect in the region

    NASA Astrophysics Data System (ADS)

    Brindley, H.; Osipov, S.; Bantges, R.; Smirnov, A.; Banks, J.; Levy, R.; Jish Prakash, P.; Stenchikov, G.

    2015-10-01

    Ground-based and satellite observations are used in conjunction with the Rapid Radiative Transfer Model (RRTM) to assess climatological aerosol loading and the associated cloud-free aerosol direct radiative effect (DRE) over the Red Sea. Aerosol optical depth (AOD) retrievals from the Moderate Resolution Imaging Spectroradiometer and Spinning Enhanced Visible and InfraRed Imager (SEVIRI) instruments are first evaluated via comparison with ship-based observations. Correlations are typically better than 0.9 with very small root-mean-square and bias differences. Calculations of the DRE along the ship cruises using RRTM also show good agreement with colocated estimates from the Geostationary Earth Radiation Budget instrument if the aerosol asymmetry parameter is adjusted to account for the presence of large particles. A monthly climatology of AOD over the Red Sea is then created from 5 years of SEVIRI retrievals. This shows enhanced aerosol loading and a distinct north to south gradient across the basin in the summer relative to the winter months. The climatology is used with RRTM to estimate the DRE at the top and bottom of the atmosphere and the atmospheric absorption due to dust aerosol. These climatological estimates indicate that although longwave effects can reach tens of W m-2, shortwave cooling typically dominates the net radiative effect over the Sea, being particularly pronounced in the summer, reaching 120 W m-2 at the surface. The spatial gradient in summertime AOD is reflected in the radiative effect at the surface and in associated differential heating by aerosol within the atmosphere above the Sea. This asymmetric effect is expected to exert a significant influence on the regional atmospheric and oceanic circulation.

  10. Exposure of rhesus monkeys to cowpox virus Brighton Red by large-particle aerosol droplets results in an upper respiratory tract disease.

    PubMed

    Johnson, Reed F; Hammoud, Dima A; Perry, Donna L; Solomon, Jeffrey; Moore, Ian N; Lackemeyer, Matthew G; Bohannon, Jordan K; Sayre, Philip J; Minai, Mahnaz; Papaneri, Amy B; Hagen, Katie R; Janosko, Krisztina B; Jett, Catherine; Cooper, Kurt; Blaney, Joseph E; Jahrling, Peter B

    2016-08-01

    We previously demonstrated that small-particle (0.5-3.0 µm) aerosol infection of rhesus monkeys (Macaca mulatta) with cowpox virus (CPXV)-Brighton Red (BR) results in fulminant respiratory tract disease characterized by severe lung parenchymal pathology but only limited systemic virus dissemination and limited classic epidermal pox-like lesion development (Johnson et al., 2015). Based on these results, and to further develop CPXV as an improved model of human smallpox, we evaluated a novel large-particle aerosol (7.0-9.0 µm) exposure of rhesus monkeys to CPXV-BR and monitored for respiratory tract disease by serial computed tomography (CT). As expected, the upper respiratory tract and large airways were the major sites of virus-induced pathology following large-particle aerosol exposure. Large-particle aerosol CPXV exposure of rhesus macaques resulted in severe upper airway and large airway pathology with limited systemic dissemination.

  11. Small particle aerosol inoculation of cowpox Brighton Red in rhesus monkeys results in a severe respiratory disease.

    PubMed

    Johnson, Reed F; Hammoud, Dima A; Lackemeyer, Matthew G; Yellayi, Srikanth; Solomon, Jeffrey; Bohannon, Jordan K; Janosko, Krisztina B; Jett, Catherine; Cooper, Kurt; Blaney, Joseph E; Jahrling, Peter B

    2015-07-01

    Cowpox virus (CPXV) inoculation of nonhuman primates (NHPs) has been suggested as an alternate model for smallpox (Kramski et al., 2010, PLoS One, 5, e10412). Previously, we have demonstrated that intrabronchial inoculation of CPXV-Brighton Red (CPXV-BR) into cynomolgus monkeys resulted in a disease that shared many similarities to smallpox; however, severe respiratory tract disease was observed (Smith et al., 2011, J. Gen. Virol.). Here we describe the course of disease after small particle aerosol exposure of rhesus monkeys using computed tomography (CT) to monitor respiratory disease progression. Subjects developed a severe respiratory disease that was uniformly lethal at 5.7 log10 PFU of CPXV-BR. CT indicated changes in lung architecture that correlated with changes in peripheral blood monocytes and peripheral oxygen saturation. While the small particle aerosol inoculation route does not accurately mimic human smallpox, the data suggest that CT can be used as a tool to monitor real-time disease progression for evaluation of animal models for human diseases. Published by Elsevier Inc.

  12. Small particle aerosol inoculation of cowpox Brighton Red in rhesus monkeys results in a severe respiratory disease

    PubMed Central

    Hammoud, Dima A.; Lackemeyer, Matthew G.; Yellayi, Srikanth; Solomon, Jeffrey; Bohannon, Jordan K.; Janosko, Krisztina B.; Jett, Catherine; Cooper, Kurt; Blaney, Joseph E.; Jahrling, Peter B.

    2015-01-01

    Cowpox virus (CPXV) inoculation of nonhuman primates (NHPs) has been suggested as an alternate model for smallpox (Kramski et al., 2010, PLoS One, 5, e10412). Previously, we have demonstrated that intrabronchial inoculation of CPXV-Brighton Red (CPXV-BR) into cynomolgus monkeys resulted in a disease that shared many similarities to smallpox; however, severe respiratory tract disease was observed (Smith et al., 2011, J. Gen. Virol). Here we describe the course of disease after small particle aerosol exposure of rhesus monkeys using computed tomography (CT) to monitor respiratory disease progression. Subjects developed a severe respiratory disease that was uniformly lethal at 5.7 log10 PFU of CPXV-BR. CT indicated changes in lung architecture that correlated with changes in peripheral blood monocytes and peripheral oxygen saturation. While the small particle aerosol inoculation route does not accurately mimic human smallpox, the data suggest that CT can be used as a tool to monitor real-time disease progression for evaluation of animal models for human diseases. PMID:25776759

  13. Aerosol delivery of trail pheromone disrupts the foraging of the red imported fire ant, Solenopsis invicta.

    PubMed

    Suckling, David Maxwell; Stringer, Lloyd D; Corn, Joshua E; Bunn, Barry; El-Sayed, Ashraf M; Vander Meer, Robert K

    2012-12-01

    The fire ant, Solenopsis invicta, is one of the most aggressive and invasive species in the world. The trail pheromone Z,E-α-farnesene (91% purity) was prepared, and disruption of worker trail orientation was tested using an ethanol-based aerosol formulation presenting a single puff of this compound by airbrush and compressed air. Trail-following behaviour was recorded by overhead webcam and ants digitised before and after presentation of the aerosol treatment at four rates (1.6, 16, 160 and 1600 ng cm(-2)). Ants preferred 110 ng cm(-1) over 11, 1.1 and 0.11 ng cm(-1) for trail following. Within seconds of presentation of 1600 ng cm(-2), the highest dose tested, trail disruption was observed. Disruption was evident as reduced arrival success and reduction in the trail integrity statistic (r(2)), as well as increased deviation from the trail (deg). The distribution of walking track angles was also flattened. The feasibility of using aerosol for delivery of trail pheromone was demonstrated, but the need for high purity combined with the difficulty of commercial supply makes this technique impractical. However, the commercial production of Z,E-α-farnesene of high purity by industrial biotechnology or from (E)-nerolidol may be possible in future, which would facilitate further development of trail pheromone disruption of S. invicta. Copyright © 2012 Society of Chemical Industry.

  14. Spatio-temporal variations in bloom of the red-tide dinoflagellate Karenia mikimotoi in Imari Bay, Japan, in 2014: Factors controlling horizontal and vertical distribution.

    PubMed

    Aoki, Kazuhiro; Kameda, Takahiko; Yamatogi, Toshifumi; Ishida, Naoya; Hirae, Sou; Kawaguchi, Mayumi; Syutou, Toshio

    2017-07-13

    A massive bloom of the dinoflagellate Karenia mikimotoi appeared in 2014 in Imari Bay, Japan. Bloom dynamics and hydrographical conditions were examined by field survey. The bloom initially developed in the eastern area of Imari Bay, subsequently after rainfall during the neap tides, cell density exceeded over 10,000cellsml. Vertical distribution of K. mikimotoi was primarily controlled by the light intensity and secondarily by the water quality during the daytime. Almost all cell-density maxima occurred in depths with weak daytime light intensities of <300μmolm(-2)s(-1). In some cases of weak light intensity, cell-density maxima occurred in depths with favorable hydrodynamic conditions for the growth. Spatially classified areas were identified by cluster analysis using the growth rate calculated from seawater temperature and salinity. This study quantitatively evaluated the environmental factors of the eastern area, where the bloom initially occurred, during the development of the bloom. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. TideNet

    DTIC Science & Technology

    2015-10-30

    Coastal Inlets Research Program TideNet The TideNet is a web-based Graphical User Interface (GUI) that provides users with GIS mapping tools to...handled using combination of databases, web programming language, Google earth and other GIS maps, and Python scripting. In addition to providing plots...information for project planning and design reports. The TideNet tool is a web-based GUI intended to provide users with a GIS mapping tool to query and

  16. Middle atmosphere tides

    NASA Technical Reports Server (NTRS)

    Forbes, J. M.

    1985-01-01

    The recent direction of theoretical and observational research in middle atmosphere tides is reviewed. The diurnal tide has received considerable emphasis, including observations of evanescent components at high latitudes, numerical simulations of nonmigrating propagating components due to longitudinally varying water vapor insolation absorption in the troposphere, and implications and origins of unsteadiness in tidal oscillations over periods of days. Recent analyses of Nimbus 7 LIMS temperatures and partial reflection drift measurements of neutral winds in the tropical mesosphere have also emphasized the diurnal propagating tide. A description of the Atmospheric Tides Middle Atmosphere Program (ATMAP) and an overview of ATMAP campaign results are also presented.

  17. Tides and Decadal Variability

    NASA Technical Reports Server (NTRS)

    Ray, Richard D.

    2003-01-01

    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."

  18. Tides and Decadal Variability

    NASA Technical Reports Server (NTRS)

    Ray, Richard D.

    2003-01-01

    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."

  19. Tide operated power generating apparatus

    SciTech Connect

    Kertzman, H. Z.

    1981-02-03

    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.

  20. Tides and tsunamis

    NASA Technical Reports Server (NTRS)

    Zetler, B. D.

    1972-01-01

    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.

  1. The Earth Tides.

    ERIC Educational Resources Information Center

    Levine, Judah

    1982-01-01

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

  2. The Earth Tides.

    ERIC Educational Resources Information Center

    Levine, Judah

    1982-01-01

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

  3. Internal tide oceanic tomography

    NASA Astrophysics Data System (ADS)

    Zhao, Zhongxiang

    2016-09-01

    A concept of internal tide oceanic tomography (ITOT) is proposed to monitor ocean warming on a global scale. ITOT is similar to acoustic tomography, but that work waves are internal tides. ITOT detects ocean temperature changes by precisely measuring travel time changes of long-range propagating internal tides. The underlying principle is that upper ocean warming strengthens ocean stratification and thus increases the propagation speed of internal tides. This concept is inspired by recent advances in observing internal tides by satellite altimetry. In particular, a plane wave fit method can separately resolve multiple internal tidal waves and thus accurately determines the phase of each wave. Two examples are presented to demonstrate the feasibility and usefulness of ITOT. In the eastern tropical Pacific, the yearly time series of travel time changes of the M2 internal tide is closely correlated with the El Niño-Southern Oscillation index. In the North Atlantic, significant interannual variations and bidecadal trends are observed and consistent with the changes in ocean heat content measured by Argo floats. ITOT offers a long-term, cost-effective, environmentally friendly technique for monitoring global ocean warming. Future work is needed to quantify the accuracy of this technique.

  4. Waves: Internal Tides

    NASA Technical Reports Server (NTRS)

    Ray, Richard D.

    1999-01-01

    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.

  5. Ocean Tide Loading Computation

    NASA Technical Reports Server (NTRS)

    Agnew, Duncan Carr

    2005-01-01

    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.

  6. Red Tide and Paralytic Shellfish Poisoning

    ERIC Educational Resources Information Center

    Dale, Barrie; Yentsch, Clarice M.

    1978-01-01

    Discusses the nature and cause of paralytic shellfish poisoning (PSP). Includes toxic dinoflagellate ecology, taxonomy and life history, and chemistry of the toxins. Recent work with trace metals and directions of future research are also given. (MA)

  7. Red Tide and Paralytic Shellfish Poisoning

    ERIC Educational Resources Information Center

    Dale, Barrie; Yentsch, Clarice M.

    1978-01-01

    Discusses the nature and cause of paralytic shellfish poisoning (PSP). Includes toxic dinoflagellate ecology, taxonomy and life history, and chemistry of the toxins. Recent work with trace metals and directions of future research are also given. (MA)

  8. King Tide floods in Tuvalu

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

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

  9. Stemming the Tide.

    ERIC Educational Resources Information Center

    Heller, Michele A.

    1994-01-01

    Hispanic Americans who fit stereotypical descriptions of illegal immigrants have become scapegoats under the rising tide of public and political pressure to crack down on illegal immigration. Provides examples of proposals to control illegal immigration and limit access to services. Summarizes studies and statistics used by both sides of the issue…

  10. Tides and Habitability

    NASA Astrophysics Data System (ADS)

    Barnes, R.

    2014-04-01

    The relatively low luminosities of M dwarfs, white dwarfs, and brown dwarfs result in habitable zones that are close enough in for strong tidal processes between the planet and its host to occur. As is well known, tidal despinning can result in slow or synchronous rotation for close-in planets, but recent investigations have revealed that tides impact habitability in other ways. Tides can drive planetary obliquity to 0, eliminating seasons and creating strong cold traps at the poles. Tides can force a migration of the semi-major axis, possibly removing planets from the habitable zone. Tidal despinning and orbital evolution produces internal heating that can alter both the interior and the atmosphere. For modest eccentricities, tidal heating can be comparable to the modern Earth's (non-tidal) energy sources, changing the thermal profile in the planet and possibly quenching dynamo generation. For larger eccentricities tidal heating can be orders of magnitude larger, suggesting some super-Earths are actually "super-Ios." In extreme cases tidal heating could trigger a runaway greenhouse for hundreds of millions of years, threatening permanent sterilization. Tides damp eccentricity, which lowers the heating rate, but companion planets can perturb orbits and maintain non-zero eccentricities. In some cases, tidal heating sustained by companions could power geochemical cycles that permit habitability for trillions of years.

  11. Ocean tide energy converter

    SciTech Connect

    Rainey, D.E.

    1980-06-24

    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.

  12. Tides and Marshes.

    ERIC Educational Resources Information Center

    Pouler, Chris

    The Maryland Marine Science Education Project has produced a series of mini-units in marine science education for the junior high/middle school classroom. This unit focuses on tides and marshes. Although the unit specifically treats the Chesapeake Bay, it may be adapted for use with similar estuarine systems. In addition, the unit may be…

  13. Stemming the Tide.

    ERIC Educational Resources Information Center

    Heller, Michele A.

    1994-01-01

    Hispanic Americans who fit stereotypical descriptions of illegal immigrants have become scapegoats under the rising tide of public and political pressure to crack down on illegal immigration. Provides examples of proposals to control illegal immigration and limit access to services. Summarizes studies and statistics used by both sides of the issue…

  14. Tides and deltaic morphodynamics

    NASA Astrophysics Data System (ADS)

    Plink-Bjorklund, Piret

    2016-04-01

    Tide-dominated and tide-influenced deltas are not widely recognized in the ancient record, despite the numerous modern and Holocene examples, including eight of the twelve modern largest deltas in the world, like the Ganges-Brahmaputra, Amazon, Chang Jiang, and Irrawadi. Furthermore, tide-dominated or tide-influenced deltas are suggested to be more common in inner-shelf or embayment settings rather than close to or at a shelf edge, primarily because wave energy is expected to be higher and tidal energy lower in outer shelf and shelf-edge areas. Thus, most shelf-edge deltas are suggested to be fluvial or wave dominated. However, there are ancient examples of tide-influenced shelf-edge deltas, indicating that the controls on tidal morphodynamics in deltas are not yet well understood. This paper asks the following questions: (1) How do tides influence delta deposition, beyond creating recognizable tidal facies? (2) Does tidal reworking create specific geometries in delta clinoforms? (3) Does tidal reworking change progradation rates of deltas? (4) Is significant tidal reworking of deltas restricted to inner-shelf deltas only? (5) What are the conditions at which deltas may be tidally influenced or tide-dominated in outer-shelf areas or at the shelf edge? (6) What are the main morphodynamic controls on the degree of tidal reworking of deltas? The paper utilizes a dataset of multiple ancient and modern deltas, situated both on the shelf and shelf edge. We show that beyond the commonly recognized shore-perpendicular morphological features and the recognizable tidal facies, the main effects of tidal reworking of deltas are associated with delta clinoform morphology, morphodynamics of delta lobe switching, delta front progradation rates, and the nature of the delta plain. Strong tidal influence is here documented to promote subaqueous, rapid progradation of deltas, by efficiently removing sediment from river mouth and thus reducing mouth bar aggradation and fluvial delta

  15. Using airborne LIDAR to measure tides and river slope

    NASA Astrophysics Data System (ADS)

    Talke, S. A.; Hudson, A.; Chickadel, C. C.; Farquharson, G.; Jessup, A. T.

    2014-12-01

    The spatial variability of tides and the tidally-averaged water-level is often poorly resolved in shallow waters, despite its importance in validating models and interpreting dynamics. In this contribution we explore using airborne LIDAR to remotely observe tides and along-river slope in the Columbia River estuary (CRE). Using an airplane equipped with LIDAR, differential GPS, and an infra-red camera, we flew 8 longitudinal transects over a 50km stretch of the CRE over a 14 hour period in June 2013. After correcting for airplane elevation, pitch and roll and median filtering over 1km blocks, a spatially-resolved data set of relative water level was generated. Results show the tide (amplitude 2m) propagating upstream at the expected phase velocity. A sinusoid with 2 periods (12.4 and 24 hours) was next fit to data to produce a smooth tide and extract the mean slope. Comparison with 4 tide gauges indicates first order agreement with measured tides (rms error 0.1m), and confirms that a substantial sub-tidal gradient exists in the CRE. This proof-of-concept experiment indicates that remote sensing of tides in coastal areas is feasible, with possible applications such as improving bathymetric surveys or inferring water depths.

  16. The presence of flour affects the efficacy of aerosolized insecticides used to treat the red flour beetle, Tribolium castaneum

    USDA-ARS?s Scientific Manuscript database

    Experiments were conducted in tightly sealed pilot-scale warehouses to assess the efficacy of common aerosolized insecticides on all life stages of Tribolium castaneum when exposed in dishes containing 0 to 2 g of wheat flour either under pallets or out in the open. Petri dishes containing 0, 0.1, ...

  17. Global detection of absorbing aerosols over the ocean in the red and near-infrared spectral region

    NASA Astrophysics Data System (ADS)

    Waquet, F.; Péré, J.-C.; Peers, F.; Goloub, P.; Ducos, F.; Thieuleux, F.; Tanré, D.

    2016-09-01

    The spatial and temporal variability of the aerosol single scattering albedo (SSA at 865 nm) has been estimated over clear-sky ocean for 2006 by using measurements acquired by POLDER (Polarization and Directionality of Earth Reflectances). Our estimates are correlated with Sun photometer retrievals (R = 0.63). Differences in SSA are generally around 0.05 and systematically fall below 0.055 for optical thicknesses ≥0.3 (at 865 nm) and modeling errors ≤3.0%. Fine absorbing aerosols (radius ≤ 0.16 μm) are detected in many coastal regions. The lowest SSAs are retrieved over the southeast Atlantic during summer (0.80), whereas nonabsorbing fine particles (≥0.98) are observed over the North Pacific. During winter, fine absorbing aerosols are detected together with mineral dust near the coasts of western Africa (0.90), over the tropical Atlantic (0.88), and around India (0.88). Long-range transport of absorbing species is also detected, as for instance over the Arctic. This study could help to constrain aerosol absorption and radiative forcing in models.

  18. Altimetry, Orbits and Tides

    NASA Technical Reports Server (NTRS)

    Colombo, O. L.

    1984-01-01

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

  19. Addition of an Aerosol Transmission Model to the Aeronautical Systems Division Infra-Red Emission Prediction Program (ASDIR).

    DTIC Science & Technology

    1979-03-01

    refraction of common aerosols has been estimated at about 1.5 by several inves- tigators, ( Volz , 1972; Hanel, 1976) while the imaginary part, is less...attenuation of the particles. Volz (1972) computed tables of average refractive indices based on studies of typical distillates of rain- water. These...particulates. The values tabulated by Volz and the extinction coeffi- cients computed from them as used in LOWTRAN are adopted without change for use

  20. Tides of the Caribbean Sea

    SciTech Connect

    Kjerfve, B.

    1981-05-20

    Analysis of tidal characteristics from 45 gauge locations indicates that the Caribbean Sea has a microtidal range, for the most part between 10 and 20 cm. The tide is primarily either mixed semidiurnal or mixed diurnal but a substantial section from Puerto Rico to Venezuela experiences diurnal tides. Empirical charts of six component tides (M/sub 2/, S/sub 2/, N/sub 2/, K/sub 1/, O/sub 1/, and P/sub 1/) show local detail of phase and amplitude. Each of the semidiurnal component tides is characterized by anticlockwise rotating amphidromes centered in the eastern Caribbean. There is evidence of strong radiational forcing of the S/sub 2/ tide in the south-western Caribbean. The diurnal component tides are largely uniform in both phase and amplitude for most of the western and central Caribbean. However, the diurnal phases increase rapidly towards the northwest and the Yucatan Channel.

  1. Study of Infra Red femtosecond laser induced aerosols using Transmission Electron Microscopy and Low Pressure Impactor: implications for LA-ICP-MS measurements

    NASA Astrophysics Data System (ADS)

    D'Abzac, F.; Seydoux-Guillaume, A.; Poitrasson, F.; Freydier, R.; Datas, L.

    2009-12-01

    Processes linked to the creation of laser induced aerosols are not yet fully understood, especially in the Infra Red femtosecond regime. It is of great interest to understand these mechanisms in order to better constrain chemical fractionation observed on LA-ICP-MS signals. A meticulous study of particles produced by IR-fs laser ablation (λ=800nm, τ=60fs, E=0,1-1mJ/pulse, f=5Hz) has been conducted on a wide variety of samples (phosphate, silicates, oxides, glass and metals), using transmission electron microscopy (Bright field TEM and EDS). Afterwards, observations using TEM coupled with focused ion beam (FIB) preparation have been performed on craters, to study the laser induced redeposition structure and chemistry and bring comparison with related aerosols. Finally, quantitative data have been collected using a low pressure impactor (LPI) device. Observed aerosols always consist in amorphous dark beads (30-150nm diameter) and more or less developed clusters (>100nm) of smaller particles (10-15 nm diameter). Their composition differs from each other and from the initial sample. Counting reveals a decreasing density of particle over 10min of ablation, while size distribution appears Gaussian, monomodal and remains centered on 90-100nm. Craters in monazite (phosphate, Moacir, Itembe, Brazil) show two different domains. Strained areas, induced by very high pressure resulting from matter removal, and, on the top, a thin layer (~250nm in the single shot crater for E=0,1mJ/pulse) probably melted then annealed. Qualitative EDS data from the latter shows the same composition as unshocked sample. Data allows an advanced reconstruction of events driving matter from crater digging through plasma and finally into metastable particles. Numerous theoretical[1] and experimental[2,3] reports, focused on each successive stage, help putting forward the hypothesis of a single complex process of condensation/coalescence. Direct qualitative and quantitative measurements on aerosols

  2. Mesospheric and thermospheric tides

    NASA Astrophysics Data System (ADS)

    Forbes, J. M.

    1980-08-01

    Recent calculations of atmospheric solar tides in the mesosphere and thermosphere are reviewed. The numerical models considered consist of a full three-dimensional solution of the tidal equations in a rotating viscous spherical atmosphere (Forbes and Garret 1976, 1978), and an approximate solution for some modes given by an equivalent gravity wave on a rotating plane (Forbes and Hagan 1979, 1980). Both models take into account eddy and molecular diffusion of heating and momentum, rotation, and hydromagnetic coupling, and use new calculations of thermal forcing by insolation absorption due to H2O and O3 below 70 km.

  3. The ultimate high tide

    SciTech Connect

    Dean, R.G. )

    1990-01-01

    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.

  4. The Presence of Flour Affects the Efficacy of Aerosolized Insecticides used to Treat the Red Flour Beetle, Tribolium castaneum

    PubMed Central

    Toews, Michael D.; Campbell, James F.; Arthur, Franklin H.

    2010-01-01

    Experiments were conducted in tightly sealed pilot scale warehouses to assess the efficacy of common aerosolized insecticides on all life stages of Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) when exposed in dishes containing 0 to 2 g of wheat flour either under pallets or out in the open. Petri dishes containing 0, 0.1, 1, or 2 g of flour were prepared with 25 eggs, 3rd instars, pupae, or adults and then immediately treated with aerosolized solvent, Pyrethrins, or esfenvalerate. Twenty-four h after insecticide exposure, the dishes were brought to the laboratory and placed in a growth chamber and held for a 3 day moribund (knockdown) assessment and a 21 day mortality assessment. Mortality in untreated controls was generally less than 10%, with the exception of the 21 day counts of adults and eggs. Solvent-treated replications followed similar trends, except that additional mortality was observed in exposed larvae and pupae. In the insecticide-treated dishes, mortality of T. castaneum provisioned with flour generally showed a linear decrease with increasing flour deposits. Regardless of life stage, mortality did not exceed 60% when individuals were exposed in petri dishes containing 2 g of flour. Exposure location also made a significant difference in observed mortality. While mortality never exceeded 75% in dishes positioned under pallets, there was never less than 80% mortality in dishes exposed in the open. Although there was a perceptible increase in mortality with esfenvalerate compared to Pyrethrins, these differences were considerably less than the variation observed among flour deposits. The study suggests that sanitation and preparation prior to aerosol insecticide treatments were more important than choice of a particular insecticide. PMID:21268701

  5. King Tides and Climate Change

    EPA Pesticide Factsheets

    The highest predicted high tide of the year at a coastal location can bring unusually high water levels and can cause flooding. Learn about these tides including what they are, when they occur, and what they can mean for the future.

  6. Forecasting Tides in Global HYCOM

    DTIC Science & Technology

    2013-05-01

    ocean tides significantly impact the deep ocean tides. Blocking the Sea of Okhotsk creates differences in the tidal amplitudes over much of the...increasing the skill. Unfortunately, we can’t use this approach in the baroclinic global model with sea ice. Tidal resonances represent a challenge for

  7. Lunar Core and Tides

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

    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.

  8. Lunar Core and Tides

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

    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.

  9. Reviews Equipment: Vibration detector Equipment: SPARK Science Learning System PS-2008 Equipment: Pelton wheel water turbine Book: Atomic: The First War of Physics and the Secret History of the Atom Bomb 1939-49 Book: Outliers: The Story of Success Book: T-Minus: The Race to the Moon Equipment: Fridge Rover Equipment: Red Tide School Spectrophotometer Web Watch

    NASA Astrophysics Data System (ADS)

    2010-03-01

    WE RECOMMEND Vibration detector SEP equipment measures minor tremors in the classroom SPARK Science Learning System PS-2008 Datalogger is easy to use and has lots of added possibilities Atomic: The First War of Physics and the Secret History of the Atom Bomb 1939-49 Book is crammed with the latest on the atom bomb T-Minus: The Race to the Moon Graphic novel depicts the politics as well as the science Fridge Rover Toy car can teach magnetics and energy, and is great fun Red Tide School Spectrophotometer Professional standard equipment for the classroom WORTH A LOOK Pelton wheel water turbine Classroom-sized version of the classic has advantages Outliers: The Story of Success Study of why maths is unpopular is relevant to physics teaching WEB WATCH IOP webcasts are improving but are still not as impressive as Jodrell Bank's Chromoscope website

  10. Venus' rotation and atmospheric tides

    NASA Technical Reports Server (NTRS)

    Ingersoll, A. P.; Dobrovolskis, A. R.

    1978-01-01

    On the basis of a presented theory, it is suggested that Venus' current rotation is a stable balance between atmospheric and solar body tides. The theory is concerned with Venus' atmospheric tides, driven by solar heating, and how these tides could serve as a third torque to balance the effects of solar body torque and to maintain a stable equilibrium resonance with regard to the earth's gravitational effects. In the absence of the atmospheric tidal torque, or some other torque, it would be expected that Venus would be despun until synchronous rotation (one side always facing the sun) is attained, rather than retain the retrograde rotation period of 243 days.

  11. Perigean Spring Tides and Apogean Neap Tides in History

    NASA Astrophysics Data System (ADS)

    Olson, Donald W.

    2012-01-01

    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.

  12. M2 world ocean tide from tide gauge measurements

    SciTech Connect

    Francis, O.; Mazzega, P. )

    1991-06-01

    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.

  13. Challenges of Mating Disruption Using Aerosol-Emitting Pheromone Puffers in Red Clover Seed Production Fields to Control Coleophora deauratella (Lepidoptera: Coleophoridae).

    PubMed

    Mori, Boyd A; Evenden, Maya L

    2015-02-01

    Sex pheromone-mediated mating disruption using pheromone puffer dispensers was evaluated to control Coleophora deauratella (Lepidoptera: Coleophoridae) at three red clover seed production fields in Alberta, Canada. The objectives of the study were to determine aspects of the biology of C. deauratella which may affect successful mating disruption, evaluate the ability of aerosol-emitting pheromone puffers to reduce male moth catch in small-plot trials, and evaluate the ability of puffers to reduce male capture in traps, larval numbers and damage in large-plot trials. The median longevity of male and female C. deauratella was 6 d in the laboratory where males emerged in larger numbers earlier than females (protandry). Male response to pheromone peaked at sunrise; thus, puffers were programmed to dispense pheromone throughout this time period. Small-plot (0.25 ha) mating disruption trials indicated that pheromone released from puffers could reduce male C. deauratella orientation to traps by 60.7 ± 18.6% compared with that in untreated control plots. Reduction of male orientation to traps in large-plot (5 ha) trials over the course of the season was also successful (93.7 ± 1.6%). However, there was no corresponding decrease in larval numbers or increase in seed yield in pheromone-treated plots. Challenges of mating disruption of C. deauratella appear to be immigration of mated females combined with high population densities.

  14. Tides in Giant Planets

    NASA Astrophysics Data System (ADS)

    Stevenson, David J.

    2015-11-01

    The arrival of Juno at Jupiter in less than a year necessitates analysis of what we can learn from the gravitational signal due to tides raised on the planet by satellites (especially Io but also Europa). In the existing literature, there is extensive work on static tidal theory (the response of the planet to a tidal potential whose time dependence is ignored) and this is what is usually quoted when people refer to tidal Love numbers. If this were correct then there would be almost no new information content in the measurement of tidally induced gravity field, since the perturbation is of the same kind as the response to rotation (i.e., the measurement of J2, a well-known quantity). However, tides are dynamic (that is, k2 is frequency dependent) and so there is new information in the frequency dependent part. There is also (highly important) information in the imaginary part (more commonly expressed as tidal Q) but there is no prospect of direct detection of this by Juno since that quadrature signal is so small. The difference between what we expect to measure and what we can already calculate directly from J2 is easily shown to be of order the square of tidal frequency over the lowest order normal mode frequency, and thus of order 10%. However, the governing equations are not simple (not separable) because of the Coriolis force. An approximate solution has been obtained for the n =1 polytrope showing that the correction to k2 is even smaller, typically a few percent, because the tidal frequency is not very different from twice the rotation frequency. Moreover, it is not highly sensitive to structure in standard models. However, the deep interior of the planet may be stably stratified because of a compositional gradient and this modifies the tidal flow amplitude, changing the dynamic k2 but not the static k2. This raises the exciting possibility that we can use the determination of k2 to set bounds on the extent of static stability, if any. There is also the slight

  15. AESOP Internal Tides and Mixing

    DTIC Science & Technology

    2012-05-04

    potential improvement over the altimeter maps (Fig. 11). • The internal tide in the Monterey Bay region has identifiable sources and beams but also...remarkable generation sites are labeled: French Frigate Shoals (FFS), Nihoa Island (NI), and Kauai Channel (KC). ZHAO ET AL.: MULTISATELLITE ALTIMETRIC...These beam patterns are used to generate energy flux maps as shown in Fig. 10 as well as to qualitatively evaluate the dominant internal tide source

  16. Tides and Modern Geodesy

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    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.

  17. Tides and Modern Geodesy

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    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.

  18. The tides of Io

    NASA Technical Reports Server (NTRS)

    Yoder, C. F.; Peale, S. J.

    1981-01-01

    A theory is developed for the origin and evaluation of the orbital resonances between the Galilean satellites Io, Europa and Ganymede as a result of the effects of dissipative tides in Jupiter and its satellites. Following a preliminary consideration of the consequences of tidal interaction for satellite orbits and a comprehensive Hamiltonian theory of the resonance interactions which allows terms up to third order in eccentricity to be included, a dynamic model of the origin and evolution of the resonance locks is presented in which the relative expansion of the orbits by tidal torques from Jupiter together with tidal dissipation in Io lead to the rapid driving out of Io until it is captured into a 2:1 resonance with Europa and the resonance with Ganymede is achieved. Consideration of the effects of other commensurabilities on the orbital evolution of the system reveals that second-order Laplace-like resonances would act to excite free eccentricites, while the resonances associated with the two-body 3:1 commensurability could not have been encountered. Analysis of the hypothesis that the Laplace relation is primordial shows that the bounds on the tidal dissipation of Jupiter still can not be relaxed. Recent determinations of the tidal dissipation in Jupiter are discussed, and it is noted that none is sufficiently small to be consistent with the high heat flux estimates for Io. Finally, the possibility of the observational determination of the tidal dissipation in Jupiter by the measurement of the secular acceleration of Io's main motion is considered.

  19. Dynamical tides reexpressed

    NASA Astrophysics Data System (ADS)

    Kushnir, Doron; Zaldarriaga, Matias; Kollmeier, Juna A.; Waldman, Roni

    2017-05-01

    Zahn first put forward and calculated in detail the torque experienced by stars in a close binary systems due to dynamical tides. His widely used formula for stars with radiative envelopes and convective cores is expressed in terms of the stellar radius, even though the torque is actually being applied to the convective core at the core radius. This results in a large prefactor, which is very sensitive to the global properties of the star, that multiplies the torque. This large factor is compensated by a very small multiplicative factor, E2. Although this is mathematically accurate, depending on the application this can lead to significant errors. The problem is even more severe, since the calculation of E2 itself is non-trivial, and different authors have obtained inconsistent values of E2. Moreover, many codes (e.g. bse, startrack, mesa) interpolate (and sometimes extrapolate) a fit of E2 values to the stellar mass, often in regimes where this is not sound practice. We express the torque in an alternate form, cast in terms of parameters at the envelope-core boundary and a dimensionless coefficient, β2. Previous attempts to express the torque in such a form are either missing an important factor, which depends on the density profile of the star, or are not easy to implement. We show that β2 is almost independent of the properties of the star and its value is approximately unity. Our formula for the torque is simple to implement and avoids the difficulties associated with the classic expression.

  20. Behavioral-physiological effects of red phosphorous smoke inhalation on two wildlife species. Task 1. Inhalation equipment development/ambient CO evaluation/aerosol distribution and air-quality study. Final report, March 1985-December 1986

    SciTech Connect

    Sterner, R.T.; Shumake, S.A.; Johns, B.E.; Thompson, R.D.

    1987-12-01

    Tests to evaluate the spatial and temporal uniformity of red phosphorous - butyl rubber smoke produced in a commercial 1-CuM inhalation chamber are described. Several modifications to the inhalation exposure system aimed at improving air filtration, relative humidity, and temperature control for the conduct of animal studies are also presented. Smoke generation involved the use of a system for the continuous generation of phosphoric acid aerosols. Assessments of spatial and temporal uniformity of smoke were based upon measurements of aerosol mass concentration (gravimetric analysis), phosphoric acid deposition (titration analysis), aerosol opacity (infrared sensor), and particle size (cascade impactor); assessments of air quality and combustion products within the chamber involved checks for oxygen, carbon dioxide, phosphine, hexane, and carbon monoxide using either gas chromatography or industrial-hygiene-analyzer tubes. Results for aerosol mass, phosphoric acid, and particle size showed that the within-chamber smoke was highly uniform among burns. Although a number of statistically significant effects were obtained, further inspection showed these to be limited to specific sampling locations and within a priori criteria established to define acceptable uniformity.

  1. Turbulent Mixing on Close-In Planets by Libration Tide

    NASA Astrophysics Data System (ADS)

    Cho, James

    2017-06-01

    A series of high-resolution, pseudospectral simulations of close-in extrasolar planet atmospheres are carried out. This study directly couples accurate fluid dynamics and orbital dynamics. The focus is on robustly capturing the global, nonlinear mixing and redistribution of passive tracers -- such as clouds, aerosols, and chemical species -- due to libration tide. Modifications of the traditional fluids equations and algorithms are discussed, as well as the role of the background mean-flow. The study shows that the mixing is enhanced and is much more complex, compared with the simple diffusion and advection reported in previous studies without the inclusion of tidal forcing.

  2. New Jersey Tide Telemetry System

    USGS Publications Warehouse

    Hoppe, Heidi L.

    2007-01-01

    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

  3. Barometric Tides from ECMWF Operational Analyses

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

    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.

  4. Thermal Tides During the 2001 Martian Global-Scale Dust Storm

    NASA Technical Reports Server (NTRS)

    Guzewich, Scott D.; Wilson, R. John; McConnochie, Timothy H.; Toigo, Anthony D.; Bandfield, Donald J.; Smith, Michael D.

    2014-01-01

    The 2001 (Mars Year 25) global dust storm radically altered the dynamics of the Martian atmosphere. Using observations from the Thermal Emission Spectrometer onboard the Mars Global Surveyor spacecraft and Mars WRF general circulation model simulations, we examine the changes to thermal tides and planetary waves caused by the storm. We find that the extratropical diurnal migrating tide is dramatically enhanced during the storm, particularly in the southern hemisphere, reaching amplitudes of more than 20 K. The tropical diurnal migrating tide is weakened to almost undetectable levels. The diurnal Kelvin waves are also significantly weakened, particularly during the period of global expansion at Ls=200deg-210deg. In contrast, the westward propagating diurnal wavenumber 2 tide strengthens to 4-8 K at altitudes above 30km. The wavenumber 1 stationary wave reaches amplitudes of 10-12 K at 50deg-70degN, far larger than is typically seen during this time of year. The phase of this stationary wave and the enhancement of the diurnal wavenumber 2 tide appear to be responses to the high-altitude westward propagating equatorial wavenumber 1 structure in dust mixing ratio observed during the storm in previous works. This work provides a global picture of dust storm wave dynamics that reveals the coupling between the tropics and high-latitude wave responses. We conclude that the zonal distribution of thermotidal forcing from atmospheric aerosol concentration is as important to understanding the atmospheric wave response as the total global mean aerosol optical depth.

  5. The magnetic tides of Honolulu

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    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.

  6. The magnetic tides of Honolulu

    USGS Publications Warehouse

    Love, Jeffrey J.; Rigler, Erin Joshua

    2013-01-01

    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.

  7. Inverse Modeling of Coastal Tides

    DTIC Science & Technology

    1999-09-30

    data in the tidal band. We have concluded that understanding this discrepancy and developing assimilation methods for baroclinic tides will require...Alexandre Kurapov to develop practical assimilation methods for coastal HF radar data. REFERENCES Bennett, A.F., B.S. Chua, and L.M. Leslie, Generalized

  8. Inverse Modeling of Coastal Tides

    DTIC Science & Technology

    1998-01-01

    produced. We are also working with Profs. J. Allen and R. Miller on developing practical assimilation methods for the coastal problem. REFERENCES...40, 81--108, 1997. Egbert, G.D. and A.F. Bennett, Data assimilation methods for ocean tides, in Modern approaches to data assimilation in ocean

  9. Barometric and Earth Tide Correction

    SciTech Connect

    Toll, Nathaniel J.

    2005-11-10

    BETCO corrects for barometric and earth tide effects in long-term water level records. A regression deconvolution method is used ot solve a series of linear equations to determine an impulse response function for the well pressure head. Using the response function, a pressure head correction is calculated and applied.

  10. Can tides influence volcanic eruptions?

    NASA Astrophysics Data System (ADS)

    Girona, T.; Huber, C.

    2015-12-01

    The possibility that the Moon-Sun gravitational force can affect terrestrial volcanoes and trigger eruptions is a controversial issue that has been proposed since ancient times, and that has been widely debated during the last century. The controversy arises mainly from two reasons. First, the days of initiation of eruptions are not well known for many volcanoes, and thus a robust statistical comparison with tidal cycles cannot be performed for many of them. Second, the stress changes induced by tides in the upper crust are very small (10-3 MPa) compared to the tensile strength of rocks (~ 10-1-10 MPa), and hence the mechanism by which tidal stresses might trigger eruptions is unclear. In this study, we address these issues for persistently degassing volcanoes, as they erupt frequently and thus the initiation time of a significant number of eruptions (>30) is well known in several cases (9). In particular, we find that the occurrence of eruptions within ±2 days from neap tides (first and third quarter moon) is lower than 34% (e.g., 29% for Etna, Italy; 28% for Merapi, Indonesia), which is the value expected if eruptions occur randomly with no external influence. To understand this preference for erupting far away from neap tides, we have developed a new lumped-parameter model that accounts for the deformation of magma reservoirs, a partially open conduit, and a gas layer where bubbles accumulate beneath volcanic craters before being released. We demonstrate that this system reservoir-conduit-gas layer acts as an amplifier of the tidal stresses, such that, when a volcano approaches to a critical state, the gas overpressure beneath the crater can reach up to several MPa more during a spring tide (full and new moon) than during a neap tide. This amplification mechanism can explain why active volcanoes are sensitive to the moon cycles.

  11. Stratospheric Tides and Data Assimilation

    NASA Technical Reports Server (NTRS)

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

    1999-01-01

    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.

  12. The magnetic tides of Honolulu

    NASA Astrophysics Data System (ADS)

    Love, Jeffrey J.; Rigler, E. Joshua

    2014-06-01

    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.

  13. New Jersey Tide Telemetry System

    USGS Publications Warehouse

    Summer, William M.

    1998-01-01

    Each summer the population of the barrier-island communities of New Jersey increases by tens of thousands. When a hurricane threatens these communities, the few 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.

  14. Weight, gravitation, inertia, and tides

    NASA Astrophysics Data System (ADS)

    Pujol, Olivier; Lagoute, Christophe; Pérez, José-Philippe

    2015-11-01

    This paper deals with the factors that influence the weight of an object near the Earth's surface. They are: (1) the Earth's gravitational force, (2) the centrifugal force due to the Earth's diurnal rotation, and (3) tidal forces due to the gravitational field of the Moon and Sun, and other solar system bodies to a lesser extent. Each of these three contributions is discussed and expressions are derived. The relationship between weight and gravitation is thus established in a direct and pedagogical manner readily understandable by undergraduate students. The analysis applies to the Newtonian limit of gravitation. The derivation is based on an experimental (or operational) definition of weight, and it is shown that it coincides with the Earth’s gravitational force modified by diurnal rotation around a polar axis and non-uniformity of external gravitational bodies (tidal term). Two examples illustrate and quantify these modifications, respectively the Eötvös effect and the oceanic tides; tidal forces due to differential gravitation on a spacecraft and an asteroid are also proposed as examples. Considerations about inertia are also given and some comments are made about a widespread, yet confusing, explanation of tides based on a centrifugal force. Finally, the expression of the potential energy of the tide-generating force is established rigorously in the appendix.

  15. The pole tide in deep oceans

    NASA Technical Reports Server (NTRS)

    Dickman, S. R.

    1990-01-01

    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.

  16. How do earth tides affect astronomers?

    NASA Technical Reports Server (NTRS)

    Sasao, T.

    1978-01-01

    Earth tides affect astronomical observations of the Earth's rotation in the following two ways: (1) verticals are deflected; and (2) the polar moment of inertia of the Earth is changed causing periodic variations in the rotation rate. The diurnal and semidiurnal tides and nutation were examined in periodic variations. Results indicate little change occured in the polar motions. Nutation observations were disturbed rather seriously by the diurnal tides.

  17. Reviews Book: At Home: A Short History of Private Life Book: The Story of Mathematics Book: Time Travel: A Writer's Guide to the Real Science of Plausible Time Travel Equipment: Rotational Inertial Wands DVD: Planets Book: The Fallacy of Fine-Tuning Equipment: Scale with Dial Equipment: Infrared Thermometers Book: 300 Science and History Projects Book: The Nature of Light and Colour in the Open Air Equipment: Red Tide Spectrometer Web Watch

    NASA Astrophysics Data System (ADS)

    2011-09-01

    WE RECOMMEND The Story of Mathematics Book shows the link between maths and physics Time Travel: A Writer's Guide to the Real Science of Plausible Time Travel Book explains how to write good time-travelling science fiction Rotational Inertial Wands Wands can help explore the theory of inertia Infrared Thermometers Kit measures temperature differences Red Tide Spectrometer Spectrometer gives colour spectra WORTH A LOOK At Home: A Short History of Private Life Bryson explores the history of home life The Fallacy of Fine-Tuning Book wades into the science/religion debate Scale with Dial Cheap scales can be turned into Newton measuring scales 300 Science History Projects Fun science projects for kids to enjoy The Nature of Light and Colour in the Open Air Text looks at fascinating optical effects HANDLE WITH CARE Planets DVD takes a trip through the solar system WEB WATCH Websites offer representations of nuclear chain reactions

  18. New aspects of the equilibrium pole tide

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

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

  19. Tide effects removed from well tests

    SciTech Connect

    Aase, E.P.B.; Jelmert, T.A.; Vik, S.A.

    1995-05-01

    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.

  20. The black tide model of QSOs

    NASA Technical Reports Server (NTRS)

    Young, P. J.; Shields, G. A.; Wheeler, J. C.

    1977-01-01

    The paper develops certain aspects of a model wherein a QSO is a massive black hole located in a dense galactic nucleus, with its growth and luminosity fueled by tidal disruption of passing stars. Cross sections for tidal disruptions are calculated, taking into account the thermal energy of stars, relativistic effects, and partial disruption removing only the outer layers of a star. Accretion rates are computed for a realistic distribution of stellar masses and evolutionary phases, the effect of the black hole on the cluster distribution is examined, and the red-giant disruption rate is evaluated for hole mass of at least 300 million solar masses, the cutoff of disruption of main-sequence stars. The results show that this black-tide model can explain QSO luminosities of at least 1 trillion suns if the black hole remains almost maximally Kerr as it grows above 100 million solar masses and if 'loss-cone' depletion of the number of stars in disruptive orbits is unimportant.

  1. Chemical Characterization and Toxicologic Evaluation of Airborne Mixtures: The Chemical and Physical Characterization of XM819 Red Phosphorus Formulation and the Aerosol Produced by Its Combustion

    DTIC Science & Technology

    1986-02-01

    Composite Infrared Spectre of XR-819 Wedge Plus . Unhardened Epon 828 ........ . ..... . . . 17 S Static 5urn Chamber . ................ 20 6 Aerosol... reflectance fourier transform Infrared spectra were recorded on a Digileb FTS-20C spectromete;. A sample of Epon 828 was received from Shell Chemical...are metal, glass and teflon to minimize artifactual contami- nation of the smoke products. The container has openings whereby air flow is regulated

  2. Tides and Trends in Higher Education.

    ERIC Educational Resources Information Center

    Fincher, Cameron

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

  3. Internal Tide Generation by Steep Topography

    DTIC Science & Technology

    2007-09-01

    acting on the barotropic tide ( Foda and Hill 1998) was incomplete. Kunze will put this work in the context of recent internal tide research and...Topographically generated internal waves in the open ocean. J. Geophys. Res., 80, 320-327. Foda , M.A., and D.F. Hill, 1998: Nonlinear energy

  4. Atmospheric Tides in Gale Crater, Mars

    NASA Technical Reports Server (NTRS)

    Guzewich, Scott D,; Newman, C. E; de la Torre Juarez, M.; Wilson, R. J.; Lemmon, M.; Smith, M. D.; Kahanpaa, H.; Harri, A.-M.

    2015-01-01

    Atmospheric tides are the primary source of daily air pressure variation at the surface of Mars. These tides are forced by solar heating of the atmosphere and modulated by the presence of atmospheric dust, topography, and surface albedo and thermal inertia. This results in a complex mix of sun-synchronous and nonsun- synchronous tides propagating both eastward and westward around the planet in periods that are integer fractions of a solar day. The Rover Environmental Monitoring Station on board the Mars Science Laboratory has observed air pressure at a regular cadence for over 1 Mars year and here we analyze and diagnose atmospheric tides in this pressure record. The diurnal tide amplitude varies from 26 to 63 Pa with an average phase of 0424 local true solar time, while the semidiurnal tide amplitude varies from 5 to 20 Pa with an average phase of 0929. We find that both the diurnal and semidiurnal tides in Gale Crater are highly correlated to atmospheric opacity variations at a value of 0.9 and to each other at a value of 0.77, with some key exceptions occurring during regional and local dust storms. We supplement our analysis with MarsWRF general circulation modeling to examine how a local dust storm impacts the diurnal tide in its vicinity. We find that both the diurnal tide amplitude enhancement and regional coverage of notable amplitude enhancement linearly scales with the size of the local dust storm. Our results provide the first long-term record of surface pressure tides near the martian equator.

  5. Aerosol Microphysics and Radiation Integration

    DTIC Science & Technology

    2016-06-07

    Evaporation Duct (RED) Experiment: An assessment of boundary layer effects in a trade winds regime on microwave and infrared propagation over the sea, Bull...L. Westphal, Preliminary Evaluation of the Impacts of Aerosol Particles on Laser Performance in the Coastal Marine Boundary Layer , NRL Technical...Aerosol, Water Vapor, and Ozone Roles Linking Solar Radiation and Climate: Results from Recent Field Experiments. Gordon Conference on Solar

  6. Organic aerosols

    SciTech Connect

    Penner, J.E.

    1994-01-01

    Organic aerosols scatter solar radiation. They may also either enhance or decrease concentrations of cloud condensation nuclei. This paper summarizes observed concentrations of aerosols in remote continental and marine locations and provides estimates for the sources of organic aerosol matter. The anthropogenic sources of organic aerosols may be as large as the anthropogenic sources of sulfate aerosols, implying a similar magnitude of direct forcing of climate. The source estimates are highly uncertain and subject to revision in the future. A slow secondary source of organic aerosols of unknown origin may contribute to the observed oceanic concentrations. The role of organic aerosols acting as cloud condensation nuclei (CCN) is described and it is concluded that they may either enhance or decrease the ability of anthropogenic sulfate aerosols to act as CCN.

  7. Oceanic tides from Geosat altimetry

    NASA Technical Reports Server (NTRS)

    Cartwright, D. E.; Ray, R. D.

    1990-01-01

    Direct tidal analysis of the altimetry from the Geosat Exact Repeat Mission's first year is used to derive estimates of the diurnal and semidiurnal oceanic tides. The geoid is removed by collinear differences at 34.1-day separation, and the orbit error is reduced by subtracting a slowly modulated 1-cycle/revolution term. A sequence of independent analyses at grid areas of 1 deg latitude x 1.5 deg longitude using 'orthotide' functions ensures complete definition of the diurnal and semidiurnal species. Global admittance maps for M2 and S2 within the latitudes 58 deg N and 59 deg S compare well with ground truth at 66 open-ocean sites. Maps of differences between Geosat and the Naval Surface Weapons Center model show important areas of the order of 10-15 cm.

  8. Pole tide triggering of seismicity

    NASA Astrophysics Data System (ADS)

    Gorshkov, V.

    2015-08-01

    The influence of the pole tide (PT) on intensity of seismic process is searched on base of Harvard Centroid-moment tensors catalogue (CMT). The normal and shear stresses excited by PT were calculated for each earthquake (EQ) from CMT (32.3 thousands of EQ events after for- and aftershock declustering). There was revealed that there are two maxima of PT influence on weak (less 5.5 magnitudes) thrust-slip EQ near the both extrema (min and max) of shear stress. This influence has 95 % level of statistical significance by Schuster and χ^2 criteria and could explain the 0.6-year periodicity in seismic intensity spectrum. The PT influence on seismicity becomes negligible when PT variations decrease up to 100~mas. This could explain 6-7 years periodicity in seismic intensity spectrum.

  9. Pole tide in the Baltic Sea

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

    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.

  10. The anomalous tides near Broad Sound

    NASA Astrophysics Data System (ADS)

    Middleton, Jason H.; Buchwald, V. T.; Huthnance, John M.

    Observations of tidal current and height, in conjunction with theoretical mathematical models are used to investigate the propagation of the tide near Broad Sound, a narrowing estuary situated on a wide section of continental shelf toward the southern end of the Great Barrier Reef. The observations indicate that the dense offshore reefs severely inhibit tidal flow, with the result that tides flood toward Broad Sound from the north and from the south, along the main lagoon. There is a local magnification of the semi-diurnal tides within Broad Sound itself. Models of flow across reefs confirm the effectiveness of dense, shallow, and broad reefs in acting as a barrier to the tide. The diffraction of tides through large gaps in the reef is modelled using conformal mapping techniques and with the inclusion of energy leakage, the diffraction model predicts magnification of the semi-diurnal tidal heights by a factor of about 4 and a phase lag of 3 h on the shelf near Broad Sound, these values being consistent with observation. The observed convergence of the tide close to, and within Broad Sound itself is consistent with the proximity of the semi-diurnal tidal period to the natural period for flow in Broad Sound, considered as a narrowing estuary. This results in further amplification, by an additional factor of about 1.5, so that the tides in Broad Sound are increased by a factor of between 5 and 6, altogether, compared with those elsewhere on the east Australian coast.

  11. Bodily Tides Near Spin-Orbit Resonances

    DTIC Science & Technology

    2012-01-01

    Rev. 8-98) Prescribed by ANSI Std Z39-18 284 M. Efroimsky Keywords Bodily tides · Body tides · Land tides · Librations · Exoplanets · Satellites...much larger than the Earth, Al 1 (see Efroimsky 2012). Hence for large terrestrial exoplanets χH I = τ−1M ζ−1. C.2.3 The intermediate band Within the...friction. Icarus 201, 1–11 (2009) Correia, A.C.M., Boué, G., Laskar, J.: Pumping the eccentricity of exoplanets by tidal effect. Astrophys. J. Lett. (2011

  12. Using an Altimeter-Derived Internal Tide Model to Remove Tides from in Situ Data

    NASA Technical Reports Server (NTRS)

    Zaron, Edward D.; Ray, Richard D.

    2017-01-01

    Internal waves at tidal frequencies, i.e., the internal tides, are a prominent source of variability in the ocean associated with significant vertical isopycnal displacements and currents. Because the isopycnal displacements are caused by ageostrophic dynamics, they contribute uncertainty to geostrophic transport inferred from vertical profiles in the ocean. Here it is demonstrated that a newly developed model of the main semidiurnal (M2) internal tide derived from satellite altimetry may be used to partially remove the tide from vertical profile data, as measured by the reduction of steric height variance inferred from the profiles. It is further demonstrated that the internal tide model can account for a component of the near-surface velocity as measured by drogued drifters. These comparisons represent a validation of the internal tide model using independent data and highlight its potential use in removing internal tide signals from in situ observations.

  13. Three-dimensional numerical simulation of thermal tides in the Martian atmosphere

    NASA Technical Reports Server (NTRS)

    Wilson, R. John

    1993-01-01

    Analysis of the Mariner 9 IRIS and Viking Orbiter IRTM temperature data and of the time series of surface pressure from the Viking landers has indicated that atmospheric thermal tides are a significant component of the martian general circulation. Classical tidal theory, considering only the Sun synchronous components, has been shown to at least roughly account for the amplitudes of the observed diurnal and semidirunal surface pressure oscillations. In particular, Zurek and Leovy have demonstrated that classical tidal theory can reproduce the observed dependence of the strength of the semidiurnal tide on aerosol optical depth. The high-amplitude topograph of Mars, however, can cause longitudinal distortions in the thermotidal forcing, leading to additional tidal modes that are not Sun synchronous. In particular, observation and theory have suggested the likely presence of a diurnal, zonal wavenumber-1 K wave. Hamilton and Garcia noted that the wavenumber-1 K normal mode has a period of close to 24 hr and may be detectable in surface pressure observations. Zurek has discussed the possibility of this mode being resonantly excited for various atmospheric temperature studies. The semidiurnal wavenumber-2 K mode, with roughly a 12-hr period, could also be resonantly excited. A numerical model with finite amplitude topography and a self-consistent thermotidal forcing resulting from the daily heat flux at the surface and atmospheric absorption of solar radiation by aerosols is used here to explore the influence of topography on martian thermal tides and to examine the possibility of Kelvin wave resonance.

  14. Investigations in Marine Chemistry: Tide Pool Ecology.

    ERIC Educational Resources Information Center

    Schlenker, Richard M.

    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)

  15. The Tides--A Neglected Topic.

    ERIC Educational Resources Information Center

    Hartel, Hermann

    2000-01-01

    Finds that computer simulations can be used to visualize the processes involved with lunar tides. Technology adds value, thus opening new paths for a more distinct analysis and increased learning results. (Author/CCM)

  16. Anchimerically Activatable Antiviral ProTides.

    PubMed

    Okon, Aniekan; Matos de Souza, Marcos Romário; Shah, Rachit; Amorim, Raquel; da Costa, Luciana Jesus; Wagner, Carston R

    2017-09-14

    This work describes the synthesis and biological evaluation of an anchimerically activated proTide of 2'-C-β-methylguanosine as an inhibitor of dengue virus 2 (DENV-2). The proTide incorporates a chemically cleavable 2-(methylthio)ethyl moiety and a HINT1 hydrolyzable tryptamine phosphoramidate. Inhibition of DENV-2 replication by proTide 6 was 5-fold greater than the parent nucleoside while displaying no apparent cytotoxicity. Furthermore, we demonstrate with a HINT1 inhibitor that the anti DENV-2 activity of the proTide correlates with the activity of HINT1. Taken together, these results demonstrate that a phosphoramidate based pronucleotide that undergoes an initial nonenzymatic activation step based on anchimeric assistance followed by P-N bond cleavage by HINT1 can be prepared.

  17. Investigations in Marine Chemistry: Tide Pool Ecology.

    ERIC Educational Resources Information Center

    Schlenker, Richard M.

    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)

  18. MST radar detection of middle atmosphere tides

    NASA Technical Reports Server (NTRS)

    Forbes, J. M.

    1983-01-01

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

  19. Mapping Hurricane Rita inland storm tide

    USGS Publications Warehouse

    Berenbrock, Charles; Mason, Jr., Robert R.; Blanchard, Stephen F.; Simonovic, Slobodan P.

    2009-01-01

    Flood-inundation data are most useful for decision makers when presented in the context of maps of effected 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 (GIS) 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-hour intervals from midnight (0000 hour) through noon (1200 hour) on September 24, 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 to 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.

  20. Mapping hurricane rita inland storm tide

    USGS Publications Warehouse

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

    2009-01-01

    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.

  1. Temperature tides determined with meteor radar

    NASA Astrophysics Data System (ADS)

    Hocking, W. K.; Hocking, A.

    2002-09-01

    A new analysis method for producing tidal temperature parameters using meteor radar measurements is presented, and is demonstrated with data from one polar and two mid-latitude sites. The technique further develops the temperature algorithm originally introduced by Hocking (1999). That earlier method was used to produce temperature measurements over time scales of days and months, but required an empirical model for the mean temperature gradient in the mesopause region. However, when tides are present, this temperature gradient is modulated by the presence of the tides, complicating extraction of diurnal variations. Nevertheless, if the vertical wavelengths of the tides are known from wind measurements, the effects of the gradient variations can be compensated for, permitting determination of temperature tidal amplitudes and phases by meteor techniques. The basic theory is described, and results from meteor radars at Resolute Bay (Canada), London (Canada) and Albuquerque (New Mexico, USA) are shown. Our results are compared with other lidar data, computer models, fundamental tidal theory and rocket data. Phase measurements at two mid-latitude sites (Albuquerque, New Mexico, and London, Canada) show times of maximum for the diurnal temperature tide to change modestly throughout most of the year, varying generally between 0 h and 6 h, with an excursion to 12 h in June at London. The semidiurnal tide shows a larger annual variation in time of maximum, being at 2 4 h in the winter months but increasing to 9 h during the late summer and early fall. We also find that, at least at mid-latitudes, the phase of the temperature tide matches closely the phase of the meridional tide, and theoretical justification for this statement is given. We also demonstrate that this is true using the Global Scale Wave Model (Hagan et al., 1999). Median values for the temperature amplitudes for each site are in the range 5 to 6 Kelvin. Results from a more northern site (Resolute Bay) show

  2. Excitation mechanism of non-migrating tides

    NASA Astrophysics Data System (ADS)

    Miyoshi, Yasunobu; Pancheva, Dora; Mukhtarov, Plamen; Jin, Hidekatsu; Fujiwara, Hitoshi; Shinagawa, Hiroyuki

    2017-04-01

    Using an atmosphere-ionosphere coupled model, the excitation source and temporal (seasonal and interannual) variations in non-migrating tides are investigated in this study. We first focus our attention on temporal variations in eastward moving diurnal tide with zonal wavenumber 3 (DE3), which is the largest of all the non-migrating tides in the mesosphere and lower thermosphere (MLT). Our simulation results indicate that upward propagation of the DE3 excited in the troposphere is sensitive to the zonal mean zonal wind in the stratosphere and mesosphere. The DE3 amplitude is enhanced in the region where the vertical shear of the zonal mean zonal wind is positive (westerly shear). Quasi-2-year variation in the DE3 amplitude in the MLT region is generated by quasi-2-year variation in the zonal mean zonal wind between 40 and 70 km, which is modulated by the stratospheric QBO. The excitation mechanisms of SW3 (westward moving semidiurnal tide with zonal wavenumber 3) and SW1 (westward moving semidiurnal tide with zonal wavenumber 1) are also investigated. During equinoxes, the SW3 and SW1 are excited by tropospheric heating (latent heat release and solar radiative heating) associated with cumulus convection in the tropics, and propagate upward into the MLT region. On the other hand, during solstices, SW3 and SW1 are generated in the winter stratosphere and mesosphere through the nonlinear interaction between the stationary planetary wave and migrating semidiurnal tide, and propagate upward to the lower thermosphere. The excitation sources of other non-migrating tides are also discussed.

  3. Internal tides in the Solomon Sea

    NASA Astrophysics Data System (ADS)

    Lionel, Tchilibou Michel; Gourdeau, Lionel; Djath, Bugshin; Lyard, Florent; Allain, Damien; Koch Larrouy, Ariane; Yoga Nogroho, Dwi; Morrow, Rosemary

    2017-04-01

    In the south west Pacific, the Solomon Sea lies on the pathway of the Low Latitudes Western Boundary Currents (LLWBCs) that connect the subtropics to the equator. The Solomon Sea have a particular interest in a climatic context, since they are a critical pathway for ENSO and its low frequency modulation. The western Pacific is a place of energetic internal tides generated over its complex bottom topographic features. In the Indonesian Archipelago, they are particularly active in defining the properties of the waters that move from the Pacific to the Indian Ocean. The salinity maximum at the thermocline level, which is characteristic of the South Pacific Tropical Waters (SPTW) flowing within the LLWBCs and feeding the Equatorial UnderCurrent, is largely eroded within the Solomon Sea. Different mechanisms could explain such salt erosion including current/bathymetry interactions, internal tides, and eddy activity. The motivation of this study is to investigate the potential role of internal tides for such water mass transformation. Results from a 1/36° resolution regional model including explicit tides are presented. As a first step, the generation and propagation of internal tides in the Solomon Sea are determined, and the conversion rate from barotropic to baroclinic energy is estimated.

  4. The Global S$_1$ Ocean Tide

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

    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.

  5. Optimizing Internal Wave Drag in a Forward Barotropic Model with Semidiurnal Tides

    DTIC Science & Technology

    2015-01-23

    Africa/Arabia (10)Andaman Sea (9)St. Law./Gulf Maine (8)China Sea (7)Arctic (6)NE. Brazil ( 5 )Patagonian Shelf (4)NW. Australian Shelf (3) Yellow Sea (2...Arctic (6)NE. Brazil ( 5 )Patagonian Shelf (4)NW. Australian Shelf (3) Yellow Sea (2)Euro Shelf (1)Hudson O8−atlas red (2.75 SSG red (2.5) (0.375) COM...with semidiurnal tides 0602435N 73-8677-03- 5 M.C. Buijsman, B.K. Arbic, J.A.M. Green, R.W. Helber, J.G. Richman, J.F. Shriver, P.G. Timko, A

  6. Obliquity Tides in Hot Jupiters

    NASA Astrophysics Data System (ADS)

    Peale, S. J.

    two papers have pointed out that this is not so (Levrard et al. 2007; Fabrycky et al. 2007). The rotation continues to decrease below the synchronous value with increasing obliquity. As is perhaps expected, state 2 becomes unstable as the planet slows. The planet then rapidly evolves to Cassini state 1 with a negligibly small obliquity, and all isolated hot Jupiters will evolve to nearly circular orbits with their spin axes nearly normal to their orbit planes. Obliquity tides cannot be invoked as a means of additional heating of hot gaseous planets.

  7. The IERS Special Bureau for Tides

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    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.

  8. Fluctuations in tides and geomagnetic variations

    NASA Astrophysics Data System (ADS)

    Kohsiek, A.; Kiefer, M.; Meek, C. E.; Manson, A. H.

    Middle atmosphere tidal winds and the daily geomagnetic Sq-variation show a day-to-day variability, both with a local behaviour. Due to the main cause of the Sq-variation, the ionospheric dynamo effect, day-to-day fluctuation of Sq could be raised by fluctuations in tides. This coupling of fluctuations is investigated with radar wind data measured at Saskatoon at around 100 km height and with magnetic data from four observatories in the vicinity of the radar. We show that our definition of fluctuations exhibits properties of atmospheric tides in the winds and that the magnetic data can be assumed to represent a local behaviour. We find that there are some significant correlations between fluctuations in winds and magnetic variations. Apparently the local fluctuation of geomagnetic variations is weakly coupled not only to the fluctuations of the semidiurnal tides but also to those of the mean winds.

  9. Dissipative tides - Application to Venus' lower atmosphere

    NASA Technical Reports Server (NTRS)

    Covey, Curt; Walterscheid, Richard L.; Schubert, Gerald

    1986-01-01

    A linearized planetary scale wave model is used to investigate the effects of thermal and mechanical damping on atmospheric tides. When the damping rate is comparable to the frequency of solar diurnal forcing the circulation consists of three parts: a classical vertically propagating 'atmospheric tide' in the upper atmosphere, a simple thermally direct subsolar-to-antisolar circulation or 'Halley cell' in most of the lower atmosphere, and finally, a reversed 'anti-Halley cell' near the surface. The near-surface circulation produces horizontal divergence near the subsolar point. While tides are a frequently encountered phenomenon (Venus, earth, and Mars), there is so far no observational evidence of a Halley circulation in any planetary atmosphere. A subsolar-antisolar circulation might be possible in Venus' slowly rotating lower atmosphere if the mechanical dissipation time scale is of the order of or less than a Venusian day. Such a circulation could be a factor in maintaining the superrotation of Venus' upper atmosphere.

  10. The IERS Special Bureau for Tides

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    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.

  11. A Model for Teaching the Dynamical Theory of Tides.

    ERIC Educational Resources Information Center

    Railsback, L. Bruce

    1991-01-01

    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)

  12. The influence of earth tides on earth's coordinates

    NASA Technical Reports Server (NTRS)

    Vincente, R. O.

    1978-01-01

    The importance of the Earth's tides on Earth coordinates were examined for the following reasons: (1) the precision for obtaining the Earth's coordinates shows that the effects of Earth tides appear on the values obtained for the coordinates; (2) the possibility of determining the values of the Earth tides; and (3) the consideration of theoretical models that can compute the values of Earth tides. The astronomical and geodetic coordinates of a point at the Earth's surface are described.

  13. New Miscellaneous Results in Tides from Topex/Poseidon

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

    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.

  14. New Miscellaneous Results in Tides from Topex/Poseidon

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

    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.

  15. ENCAPSULATED AEROSOLS

    DTIC Science & Technology

    acetate, polymerized rapidly and produced some polymer film encapsulation of the aerosol droplets. A two-stage microcapsule generator was designed...encapsulating material, the generator also produced microcapsules of dibutyl phosphite in polyethylene, nitrocellulose, and natural rubber.

  16. Using Tide Data in Introductory Classes

    ERIC Educational Resources Information Center

    De Jong, Marvin L.

    2006-01-01

    Oceantides are not typically high in our consciousness here in Missouri, but in teaching astronomy and physical science the subject always comes up, and teachers of physical science and astronomy are all quite familiar with the textbook explanations. Our goal here is not to explain tides but to make some suggestions about how, on their own,…

  17. Nonlinearity in rock - Evidence from earth tides

    NASA Technical Reports Server (NTRS)

    Agnew, D. C.

    1981-01-01

    The earth is sinusoidally stressed by tidal forces; if the stress-strain relation for rock is nonlinear, energy should appear in an earth tide record at frequencies which are multiples of those of the larger tidal lines. An examination of the signals to be expected for different nonlinear deformation laws shows that for a nonlinear response without dissipation, the largest anomalous signal should occur at twice the forcing frequency, whereas for nonlinear laws involving dissipation (cusped hysteresis loops) the anomalous signal will be greatest at three times this frequency. The size of the signal in the dissipative case depends on the amount by which dissipation affects the particular response being measured. For measurements of strain tides this depends on whether dissipation is assumed to be present throughout the earth or localized around the point of measurement. An analysis of 5.7 years of strain tide records from Pinon Flat, California, shows a small signal at twice the frequency of the largest (M2) tide.

  18. FULLY COMPRESSIVE TIDES IN GALAXY MERGERS

    SciTech Connect

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

    2009-11-20

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

  19. Semidiurnal solar tides in the mountain atmosphere

    SciTech Connect

    Whiteman, C.D.; Bian, X.

    1994-09-01

    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.

  20. Parents Who Moved against the Tide.

    ERIC Educational Resources Information Center

    Perske, Robert

    2003-01-01

    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)

  1. Using Tide Data in Introductory Classes

    ERIC Educational Resources Information Center

    De Jong, Marvin L.

    2006-01-01

    Oceantides are not typically high in our consciousness here in Missouri, but in teaching astronomy and physical science the subject always comes up, and teachers of physical science and astronomy are all quite familiar with the textbook explanations. Our goal here is not to explain tides but to make some suggestions about how, on their own,…

  2. A tide prediction and tide height control system for laboratory mesocosms

    PubMed Central

    Long, Jeremy D.

    2015-01-01

    Experimental mesocosm studies of rocky shore and estuarine intertidal systems may benefit from the application of natural tide cycles to better replicate variation in immersion time, water depth, and attendant fluctuations in abiotic and edaphic conditions. Here we describe a stand-alone microcontroller tide prediction open-source software program, coupled with a mechanical tidal elevation control system, which allows continuous adjustment of aquarium water depths in synchrony with local tide cycles. We used this system to monitor the growth of Spartina foliosa marsh cordgrass and scale insect herbivores at three simulated shore elevations in laboratory mesocosms. Plant growth decreased with increasing shore elevation, while scale insect population growth on the plants was not strongly affected by immersion time. This system shows promise for a range of laboratory mesocosm studies where natural tide cycling could impact organism performance or behavior, while the tide prediction system could additionally be utilized in field experiments where treatments need to be applied at certain stages of the tide cycle. PMID:26623195

  3. A tide prediction and tide height control system for laboratory mesocosms.

    PubMed

    Miller, Luke P; Long, Jeremy D

    2015-01-01

    Experimental mesocosm studies of rocky shore and estuarine intertidal systems may benefit from the application of natural tide cycles to better replicate variation in immersion time, water depth, and attendant fluctuations in abiotic and edaphic conditions. Here we describe a stand-alone microcontroller tide prediction open-source software program, coupled with a mechanical tidal elevation control system, which allows continuous adjustment of aquarium water depths in synchrony with local tide cycles. We used this system to monitor the growth of Spartina foliosa marsh cordgrass and scale insect herbivores at three simulated shore elevations in laboratory mesocosms. Plant growth decreased with increasing shore elevation, while scale insect population growth on the plants was not strongly affected by immersion time. This system shows promise for a range of laboratory mesocosm studies where natural tide cycling could impact organism performance or behavior, while the tide prediction system could additionally be utilized in field experiments where treatments need to be applied at certain stages of the tide cycle.

  4. Tropospheric Aerosols

    NASA Astrophysics Data System (ADS)

    Buseck, P. R.; Schwartz, S. E.

    2003-12-01

    It is widely believed that "On a clear day you can see forever," as proclaimed in the 1965 Broadway musical of the same name. While an admittedly beautiful thought, we all know that this concept is only figurative. Aside from Earth's curvature and Rayleigh scattering by air molecules, aerosols - colloidal suspensions of solid or liquid particles in a gas - limit our vision. Even on the clearest day, there are billions of aerosol particles per cubic meter of air.Atmospheric aerosols are commonly referred to as smoke, dust, haze, and smog, terms that are loosely reflective of their origin and composition. Aerosol particles have arisen naturally for eons from sea spray, volcanic emissions, wind entrainment of mineral dust, wildfires, and gas-to-particle conversion of hydrocarbons from plants and dimethylsulfide from the oceans. However, over the industrial period, the natural background aerosol has been greatly augmented by anthropogenic contributions, i.e., those produced by human activities. One manifestation of this impact is reduced visibility (Figure 1). Thus, perhaps more than in other realms of geochemistry, when considering the composition of the troposphere one must consider the effects of these activities. The atmosphere has become a reservoir for vast quantities of anthropogenic emissions that exert important perturbations on it and on the planetary ecosystem in general. Consequently, much recent research focuses on the effects of human activities on the atmosphere and, through them, on the environment and Earth's climate. For these reasons consideration of the geochemistry of the atmosphere, and of atmospheric aerosols in particular, must include the effects of human activities. (201K)Figure 1. Impairment of visibility by aerosols. Photographs at Yosemite National Park, California, USA. (a) Low aerosol concentration (particulate matter of aerodynamic diameter less than 2.5 μm, PM2.5=0.3 μg m-3; particulate matter of aerodynamic diameter less than 10

  5. Tides of global ice-covered oceans

    NASA Astrophysics Data System (ADS)

    Wunsch, Carl

    2016-08-01

    The tides of an ice-covered ocean are examined using a Cartesian representation of the elastic and fluid equations. Although unconstrained by any observations, the ocean tides of a Neoproterozoic "snowball" Earth could have been significantly larger than they are today. Time-mean tidal-residual circulations would then have been set up that are competitive with the circulation driven by geothermal heating. In any realistic configuration, the snowball Earth would have had an ice cover that is in the thin shell limit, but by permitting the ice thickness to become large, more interesting ice tidal response can be found, ones conceivably of application to bodies in the outer Solar System or hypothetical exoplanets. Little can be said concerning a reduction in tidal dissipation necessary to avoid a crisis in the history of the lunar orbit.

  6. Tide-influenced sedimentary environments and facies

    SciTech Connect

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

    1988-01-01

    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.

  7. Aerosol Blanket Likely Thinned During 1990s

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Each day, a blanket of tiny particles drifting through the Earth's atmosphere filters out some of the sunlight headed for the planet's surface. These aerosols, including dust, smoke, and human-produced pollution, can reflect incoming light or absorb it, directly affecting the Earth's energy balance and climate. Aerosols also influence the climate indirectly, by affecting the brightness and amount of clouds. Research by NASA scientists on global aerosol patterns since the 1990s indicate the global aerosol blanket has likely thinned, allowing more sunlight to reach the Earth's surface over the past decade. The thinning of the blanket is shown by this trio of images based on satellite observations of aerosol optical thickness, a measurement that scientists use to describe how much the aerosols filter the incoming sunlight. Higher optical thickness (orange and red) means more sunlight blocking. The globes show average aerosol optical thickness for 1988-1991 (top), 2002-2005 (middle), and the change between the two time periods (bottom). Overall, the 1988-1991 image appears redder, a sign that aerosols were blocking more incoming sunlight; the 2002-2005 image has more light yellow areas. In the bottom image, small pockets of red (increased aerosol optical thickness), mostly near land masses in the Northern Hemisphere, are far outnumbered by blue areas (decreased aerosol optical thickness). Because they block incoming sunlight from reaching Earth's surface, aerosols may counterbalance greenhouse gas warming. The decline in the dimming power of aerosols over the past decade may have made the greenhouse warming trend more evident in the past decade than in previous decades. The scientists describe their results as a 'likely' trend because the National Oceanic and Atmospheric Administration satellite sensors they used in their analysis were not specifically designed to observe aerosols, and may contain some errors. However, specific, major aerosol events, such as large

  8. Deep sea tides determination from GEOS-3

    NASA Technical Reports Server (NTRS)

    Maul, G. A.; Yanaway, A.

    1978-01-01

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

  9. Tides and the evolution of planetary habitability.

    PubMed

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

    2008-06-01

    Tides raised on a planet by the gravity of its host star can reduce the 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 ( less or similar to 0.35 M(circle)). Such migration may have important implications for the evolution of the atmosphere, internal heating, and the Gaia hypothesis. Similarly, a planet that is detected interior to the habitable zone could have been habitable in the past. We consider the past habitability of the recently discovered, approximately 5 M(circle) 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 constraints derived from the additional companions are included, most parameter choices that indicate 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.

  10. Manuel Johnson's Tide Record at St. Helena

    NASA Technical Reports Server (NTRS)

    Cartwright, David E.; Woodworth, Philip L.; Ray, Richard D.

    2017-01-01

    The astronomer Manuel Johnson, a future President of the Royal Astronomical Society, recorded the ocean tides with his own instrument at St. Helena in 1826-1827, while waiting for an observatory to be built. It is an important record in the history of tidal science, as the only previous measurements at St. Helena had been those made by Nevil Maskelyne in 1761, and there were to be no other systematic measurements until the late 20th century. Johnsons tide gauge, of a curious but unique design, recorded efficiently the height of every tidal high and low water for at least 13 months, in spite of requiring frequent re-setting. These heights compare very reasonably with a modern tidal synthesis based on present-day tide gauge measurements from the same site.Johnsons method of timing is unknown, but his calculations of lunar phases suggest that his tidal measurements were recorded in Local Apparent Time. Unfortunately, the recorded times are found to be seriously and variably lagged by many minutes. Johnsons data have never been fully published, but his manuscripts have been safely archived and are available for inspection at Cambridge University. His data have been converted to computerfiles as part of this study for the benefit of future researchers.

  11. Tides In The Subglacial Lake Vostok, Antarctica

    NASA Astrophysics Data System (ADS)

    Dietrich, R.; Shibuya, K.; Pötzsch, A.; Ozawa, T.

    Subglacial lakes belong to the most interesting glaciological features in Antarctica, where the 240-km-long Lake Vostok is the most prominent one. For the understanding of the dynamics of the Lake Vostok system different compo- nents such as ice thickness and ice motion, lake bathymetry, geothermal heat flow, water circulation and melting-refreezing have to be investigated and modelled in a complex way. An aspect, which has not been considered yet, are lake tides. We present evidence based on observations which indicate the existence of tides in the lake. Earlier gravimetric tidal observations at Vostok Station show a significant deviation from theoretical solid earth tides which may be explained as the tidal effect of the water underneath the station. Interferometric SAR analysis yields a specific sur- face deformation pattern which is interpreted as a tidal signal too. According to our estimation the resulting magnitude of the vertical surface deformation is in the order of a few centimetres. The role of a `tidal pump' concerning the water circulation in the lake will be empha- sized.

  12. Internal tide in the Kara Gates Strait

    NASA Astrophysics Data System (ADS)

    Morozov, E. G.; Kozlov, I. E.; Shchuka, S. A.; Frey, D. I.

    2017-01-01

    We observed strong internal tidal waves in the Kara Gates Strait. Internal tides are superimposed over a system of mean currents from the Barents to the Kara Sea. Field studies of internal tides in the Kara Gates were performed in 1997, 2007, and 2015. In 2015, we analyzed data from towed CTD measurements, numerical model calculations, and satellite images in the region. An internal tidal wave with a period of 12.4 h is generated due to the interaction between the currents of the barotropic tide and the bottom relief on the slopes of a ridge that crosses the strait from Novaya Zemlya to the continent. The depths of the ridge crest are 30-40 m. A constant current of relatively warm water flows from the Barents to the Kara Sea. An internal wave propagates in both directions from the ridge. In the Barents Sea, internal waves are intensified by the current from the Barents to the Kara Sea. Internal bores followed by a packet of short-period internal waves are found in both directions from the strait. Satellite images show that short-period internal waves are generated after the internal bore. A hydraulic jump was found on the eastern side of the strait. Numerical modeling agrees with the experimental results.

  13. Manuel Johnson's tide record at St. Helena

    NASA Astrophysics Data System (ADS)

    Cartwright, David E.; Woodworth, Philip L.; Ray, Richard D.

    2017-03-01

    The astronomer Manuel Johnson, a future President of the Royal Astronomical Society, recorded the ocean tides with his own instrument at St. Helena in 1826-1827, while waiting for an observatory to be built. It is an important record in the history of tidal science, as the only previous measurements at St. Helena had been those made by Nevil Maskelyne in 1761, and there were to be no other systematic measurements until the late 20th century. Johnson's tide gauge, of a curious but unique design, recorded efficiently the height of every tidal high and low water for at least 13 months, in spite of requiring frequent re-setting. These heights compare very reasonably with a modern tidal synthesis based on present-day tide gauge measurements from the same site. Johnson's method of timing is unknown, but his calculations of lunar phases suggest that his tidal measurements were recorded in Local Apparent Time. Unfortunately, the recorded times are found to be seriously and variably lagged by many minutes. Johnson's data have never been fully published, but his manuscripts have been safely archived and are available for inspection at Cambridge University. His data have been converted to computer files as part of this study for the benefit of future researchers.

  14. Downwelling wind, tides, and estuarine plume dynamics

    NASA Astrophysics Data System (ADS)

    Lai, Zhigang; Ma, Ronghua; Huang, Mingfen; Chen, Changsheng; Chen, Yong; Xie, Congbin; Beardsley, Robert C.

    2016-06-01

    The estuarine plume dynamics under a downwelling-favorable wind condition were examined in the windy dry season of the Pearl River Estuary (PRE) using the PRE primitive-equation Finite-Volume Community Ocean Model (FVCOM). The wind and tide-driven estuarine circulation had a significant influence on the plume dynamics on both local and remote scales. Specifically, the local effect of downwelling-favorable winds on the plume was similar to the theoretical descriptions of coastal plumes, narrowing the plume width, and setting up a vertically uniform downstream current at the plume edge. Tides tended to reduce these plume responses through local turbulent mixing and advection from upstream regions, resulting in an adjustment of the isohalines in the plume and a weakening of the vertically uniform downstream current. The remote effect of downwelling-favorable winds on the plume was due to the wind-induced estuarine sea surface height (SSH), which strengthened the estuarine circulation and enhanced the plume transport accordingly. Associated with these processes, tide-induced mixing tended to weaken the SSH gradient and thus the estuarine circulation over a remote influence scale. Overall, the typical features of downwelling-favorable wind-driven estuarine plumes revealed in this study enhanced our understanding of the estuarine plume dynamics under downwelling-favorable wind conditions.

  15. Interactions between tides and other frequencies in the Indonesian seas

    NASA Astrophysics Data System (ADS)

    Robertson, Robin

    2011-01-01

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

  16. Atmospheric tides in Earth-like planets

    NASA Astrophysics Data System (ADS)

    Auclair-Desrotour, P.; Laskar, J.; Mathis, S.

    2017-07-01

    Context. Atmospheric tides can strongly affect the rotational dynamics of planets. In the family of Earth-like planets, which includes Venus, this physical mechanism coupled with solid tides makes the angular velocity evolve over long timescales and determines the equilibrium configurations of their spin. Aims: Unlike the solid core, the atmosphere of a planet is subject to both tidal gravitational potential and insolation flux coming from the star. The complex response of the gas is intrinsically linked to its physical properties. This dependence has to be characterized and quantified for application to the wide variety of extrasolar planetary systems. Methods: We develop a theoretical global model where radiative losses, which are predominant in slowly rotating atmospheres, are taken into account. We analytically compute the perturbation of pressure, density, temperature, and velocity field caused by a thermogravitational tidal perturbation. From these quantities, we deduce the expressions of atmospheric Love numbers and tidal torque exerted on the fluid shell by the star. The equations are written for the general case of a thick envelope and the simplified one of a thin isothermal atmosphere. Results: The dynamics of atmospheric tides depends on the frequency regime of the tidal perturbation: the thermal regime near synchronization and the dynamical regime characterizing fast-rotating planets. Gravitational and thermal perturbations imply different responses of the fluid, i.e. gravitational tides and thermal tides, which are clearly identified. The dependence of the torque on the tidal frequency is quantified using the analytic expressions of the model for Earth-like and Venus-like exoplanets and is in good agreement with the results given by global climate models (GCM) simulations.Introducing dissipative processes such as radiation regularizes the tidal response of the atmosphere, otherwise it is singular at synchronization. Conclusions: We demonstrate the

  17. NONLINEAR TIDES IN CLOSE BINARY SYSTEMS

    SciTech Connect

    Weinberg, Nevin N.; Arras, Phil; Quataert, Eliot; Burkart, Josh

    2012-06-01

    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

  18. What can earth tide measurements tell us about ocean tides or earth structure?

    NASA Technical Reports Server (NTRS)

    Baker, T. F.

    1978-01-01

    Current experimental problems in Earth tides are reviewed using comparisons of tidal gravity and tilt measurements in Europe with loading calculations are examples. The limitations of present day instrumentation and installation techniques are shown as well as some of the ways in which they can be improved. Many of the geophysical and oceanographic investigations that are possible with Earth tide measurements are discussed with emphasis on the percentage accuracies required in the measurements in order to obtain new information about Earth or its oceans.

  19. Long-period perturbations in Starlette orbit and tide solution

    SciTech Connect

    Cheng, M.K.; Shum, C.K.; Eanes, R.J.; Schutz, B.E.; Tapley, B.D. )

    1990-06-10

    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.

  20. Implementation of Structures in the CMS: Part 4, Tide Gate

    DTIC Science & Technology

    2013-08-01

    salinity and sediment management (Figure 1). Because a tide gate is a significant component of hydrodynamic and sediment transport controls in the coastal... transport , and morphology change in coastal and inlet applications. It consists of a hydrodynamic and sediment transport model, CMS-Flow, and a spectral...sediment transport with tide gates, the salinity and suspended sediment will be transported over tide gate structures, but the bed load will be trapped if

  1. The Role of Gravity Waves in Modulating Atmospheric Tides

    NASA Technical Reports Server (NTRS)

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

    1999-01-01

    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.

  2. Precise comparisons of bottom-pressure and altimetric ocean tides

    NASA Astrophysics Data System (ADS)

    Ray, R. D.

    2013-09-01

    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 core-nutation 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.

  3. Precise Comparisons of Bottom-Pressure and Altimetric Ocean Tides

    NASA Technical Reports Server (NTRS)

    Ray, Richard D.

    2013-01-01

    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.

  4. Oceanic tide maps and spherical harmonic coefficients from Geosat altimetry

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

    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.

  5. Antarctic tides from GRACE satellite accelerations

    NASA Astrophysics Data System (ADS)

    Wiese, D. N.; Killett, B.; Watkins, M. M.; Yuan, D.-N.

    2016-05-01

    The extended length of the GRACE data time series (now 13.5 years) provides the unique opportunity to estimate global mass variations due to ocean tides at large (˜300 km) spatial scales. State-of-the-art global tide models rely heavily on satellite altimetry data, which are sparse for latitudes higher than 66°. Thus, the performance of the models is typically worse at higher latitudes. GRACE data, alternately, extend to polar latitudes and therefore provide information for both model validation and improvement at the higher latitudes. In this work, 11 years of GRACE inter-satellite range-acceleration measurements are inverted to solve for corrections to the amplitudes and phases of the major solar and lunar ocean tidal constituents (M2, K1, S2, and O1) from the GOT4.7 ocean tide model at latitudes south of 50°S. Two independent inversion and regularization methods are employed and compared against one another. Uncertainty estimates are derived by subtracting two independent solutions, each spanning a unique 5.5 years of data. Features above the noise floor in the derived solutions likely represent errors in GOT4.7. We find the GOT4.7 amplitudes to be generally too small for M2 and K1, and too large for S2 and O1, and to spatially correlate with geographic regions where GOT4.7 predicts the largest tidal amplitudes. In particular, we find GOT4.7 errors to be dominant over the Patagonia shelf (M2), the Filchner-Ronne Ice Shelf (M2 and S2), the Ross Ice Shelf (S2), and the Weddell and Ross Seas (K1 and O1).

  6. Numerical simulation of tides in Ontario Lacus

    NASA Astrophysics Data System (ADS)

    Vincent, David; Karatekin, Ozgür

    2015-04-01

    Hydrocarbons liquid filled lakes has been recently detected on Titan's surface. Most of these lakes are located in the northern latitudes but there is a substantial lake in the southern latitudes: Ontario Lacus. This lake gets our attention because of possible shoreline changes suggested by Cassini flybys over Ontario Lacus between September 2005 (T7) et January 2010 (T65). The shoreline changes could be due to evaporation-precipitation processes but could also be a consequence of tides. Previous studies showed that the maximal tidal amplitudes of Ontario Lacus would be about 0.2m (for an uniform bathymetry of 20m). In this study we simulate tidal amplitude and currents with SLIM (Second-generation Louvain-la-Neuve Ice-ocean Model, http://sites.uclouvain.be/slim/ ) which resolves 2D shallow water equation on an unstructured mesh. Unstructured mesh prevents problems like mesh discontinuities at poles and allows higher accuracy at some place like coast or straits without drastically increasing computing costs. The tide generating force modeled in this work is the gradient of tidal potential due to titan's obliquity and titan's orbital eccentricity around Saturn (other contribution such as sun tide generating force are unheeded). The uncertain input parameters such as the wind direction and amplitude, bottom friction and thermo-physical properties of hydrocarbons liquids are varied within their expected ranges. SAR data analysis can result in different bathymetry according to the method. We proceed simulations for different bathymetries: tidal amplitudes doesn't change but this is not the case for tidal currents. Using a recent bathymetry deduced from most recent RADAR/SAR observations and a finer mesh, the peak-to peak tidal amplitudes are calculated to be up to 0.6 m. which is more than a factor two larger than the previous results. The maximal offshore tidal currents magnitude is about 0.06 m/s.

  7. The GPS Tide Gauge Problem Revisited

    NASA Astrophysics Data System (ADS)

    Larson, K. M.; Löfgren, J. S.; Haas, R.

    2011-12-01

    It is well-known that GPS instruments can be used to measure local sea level. In most experiments, two antennas are deployed at a coastal site. A geodetic antenna - optimized for RHCP signals - is used in the traditional orientation and tracks the direct signal. The second antenna is optimized for reflected signals - which are primarily LHCP - and is pointed towards the ocean. The sea surface can then be estimated by analyzing the carrier phase data. While the data from the "up" antenna are dominated by the direct signal, the effects of signals reflected from the ocean are also present in its data. Thus in principle, one might be able to estimate sea level using only data from the "up" antenna. This is similar in concept to recent multipath studies where geodetic GPS installations are being used to measure soil moisture variations and snow depth. We have analyzed GPS data for a three-month period from a GPS tide gauge installation at the Onsala Space Observatory. It is located on the western coast of Sweden. We used the SNR data from the "up" antenna only. The data were windowed by azimuth for ocean-reflections and elevation angles from 18-40 degrees. This provides hourly sea level measurements. Comparisons were made to an average for tide gauge records 18 km south and 33 km north of Onsala. The standard deviation of the residual between our solutions and the tide gauges is 4.9 cm. This is less precise than the combined up-down antenna system of 2.6 cm. These precision values include errors associated with real tidal motion at the GPS site. While the "down" antenna performs poorly in high-wind conditions (> 8 m/s), we found that the "up" antenna performs significantly better at these times.

  8. ENCAPSULATED AEROSOLS

    DTIC Science & Technology

    materials determine the range of applicability of each method. A useful microencapsulation method, based on coagulation by inertial force was developed...The generation apparatus, consisting of two aerosol generators in series, was utilized to produce many kinds of microcapsules . A fluid energy mill...was found useful for the production of some microcapsules . The permeability of microcapsule films and the effect of exposure time and humidity were

  9. On the detectability of internal tides in Drake Passage

    NASA Astrophysics Data System (ADS)

    Heywood, Karen J.; Collins, Julie L.; Hughes, Christopher W.; Vassie, Ian

    2007-11-01

    The Southern Ocean hosts significant topographic mixing that might be associated with internal tides. Tidal signals are evident in bottom temperature at 1000 m in Drake Passage, suggesting that internal tides with an amplitude of between ˜20 and 200 m may be present. Various necessary conditions for internal tide generation show that the steep topography in and around Drake Passage can initiate internal tides, and recent global tide models have suggested this region to generate very large interface displacements. Here, we present an attempt to detect internal tides in Drake Passage. During the last 10 years, combinations of bottom pressure recorders and inverted echo sounders have been deployed in the region. The bottom pressure recorders measure predominantly the barotropic tide; the inverted echo sounders measure travel time from sea bed to sea surface and therefore are influenced both by sea level (barotropic tide) and internal sound speed (internal tide). By subtracting one from the other, the internal tide should be detectable. Although the technique works successfully around Hawaii, it does not prove the existence of large internal tides in Drake Passage. The detectability of the internal tidal signal in Drake Passage is investigated using a six-layer one-dimensional model to simulate the bottom pressure and travel time signals of a semi-diurnal tide. The temperature and salinity stratification in Drake Passage is sufficiently weak that large vertical excursions are necessary to produce a signal in travel time detectable above the noise in Drake Passage. An internal tide of at least 70 or 20 m in northern and southern Drake Passage, respectively, would be detected. The fact that these are, perhaps surprisingly, not detected by the combination of bottom pressure and travel time, constrains the internal tides in Drake Passage to be ˜20 m in southern Drake Passage, and between 20 and 70 m in northern Drake Passage. The model also predicts that satellite

  10. A description of the tides in the Eastern North Atlantic

    NASA Astrophysics Data System (ADS)

    Fanjul, Enrique Alvarez; Gómez, Begoña Pérez; Sánchez-Arévalo, Ignacio Rodríguez

    A description of the Eastern North Atlantic tidal dynamics (in a region spanning from 20°N to 48°N in latitude and from 34°W to 0° in longitude) is obtained by means of new in situ measurements and numerical modelling based on TOPEX/POSEIDON-derived data sets. The main source of measurements is the tide gauge network REDMAR (RED de MAReógrafos de Puertos del Estado), operative since July 1992 and managed by Clima Marítimo (Puertos del Estado). Results derived from the harmonic analysis of the first years of measurements are presented and compared with model results. In order to obtain a global picture of the tides in the region, a large compilation of harmonic constants obtained from other institutes is included. The availability of new TOPEX/POSEIDON-derived harmonic constants data sets provides a chance to include the benefits derived from satellite altimetry in high resolution regional applications of numerical models. Richard Ray's tidal model (Ray et al., 1994), based on a response type tidal analysis of TOPEX/POSEIDON data, was employed within a model of the studied area. The numerical model employed is HAMSOM, a 3-D finite difference code developed both by the Institut für Meereskunde (Hamburg University) and Clima Marítimo. Results from simulations of seven major harmonics are presented, providing a comprehensive view of tidal dynamics, including current information. The results of tidal simulations show good agreement between semidiurnal harmonic components and the values measured by both coastal and pelagic tidal gauges and by current meters. The modelled diurnal constituents show larger relative differences with measurements than semidiurnal harmonics, especially concerning the phase lags. The non-linear transfer of energy from semidiurnal to higher order harmonics, such as M 4 and M 6, was mapped. Those transfers were found to be important only in two areas: the French continental shelf in the Bay of Biscay and the widest part of the African

  11. Auroral effects on midlatitude semidiurnal tides

    SciTech Connect

    Fesen, C.G. ); Richmond, A.D.; Roble, R.G. )

    1991-03-01

    The effect of auroral activity on mid-latitude semidiurnal tides was investigated using simulations from the NCAR Thermosphere/Ionosphere General Circulation Model (TIGCM). Model runs were made for solar cycle minimum equinox conditions for four levels of geomagnetic activity parameterized by the total hemispheric power index and the cross polar cap potential drop. Simulations at 42.5{degree}N (gg) predicted that the upper thermosphere semidiurnal winds and temperatures generally increase with increasing geomagnetic activity, while the lower thermosphere fields were relatively insensitive to the level of auroral forcing in the model. The modeled semidiurnal mid-latitude tidal response was determined by the magnitude and phasing of the waves generated by in situ solar forcing and the auroral momentum and energy sources, in conjunction with those propagating up from the lower atmosphere. The predicted sensitivity of the model tides to the level of geomagnetic activity may contribute to the observed tidal variability at mid latitudes. Successful modeling of observations will require careful specification of the high-latitude energy and momentum sources.

  12. Europa Tide Inversion from REASON Altimetry

    NASA Astrophysics Data System (ADS)

    Haynes, M.; Schroeder, D. M.; Steinbrügge, G.; Bills, B. G.

    2015-12-01

    Determining the amplitude of Europa's tides is central to understanding its ice shell and subsurface ocean. We assess the accuracy of retrieving the tidal amplitude solely using altimetry profiles produced by the REASON instrument (Radar for Europa Assessment and Sounding: Ocean to Near-surface), selected for the Europa Clipper mission. We investigate retrieval of the first Love number, h2, by inverting the entire set of altimetric ground tracks over the life of the mission. The inversion simultaneously estimates h2, long-wavelength topography, and spacecraft orbit parameters. In its simplest form, the inversion is quite robust: the time and location of the ground track uniquely fixes the phase of the sampled tide, where surface roughness acts as noise to be averaged out. In addition, we make an initial evaluation of altimetric biases that arise from known and hypothesized Europa topography using surface point target simulations. Overall, we find that the altimeter alone is capable of retrieving the first tidal Love number with accuracy sufficient to observationally constrain ice-shell thickness.

  13. Surface Pressure Measurements of Atmospheric Tides Using Smartphones

    NASA Astrophysics Data System (ADS)

    Price, Colin; Maor, Ron

    2017-04-01

    Similar to the oceans, the atmosphere also has tides that are measured in variations of atmospheric pressure. However, unlike the gravitational tides in the oceans, the atmospheric tides are caused primarily in the troposphere and stratosphere when the atmosphere is periodically heated by the sun, due to tropospheric absorption by water vapor and stratospheric absorption by ozone. Due to the forcing being always on the day side of the globe, the tides migrate around the globe following the sun (migrating tides) with a dominant periodicity of 12 hours (and less so at 24 hours). In recent years smartphones have been equipped with sensitive, cheap and reliable pressure sensors that can easily detect these atmospheric tides. By 2020 it is expected that there will be more than 6 billion smartphones globally, each measuring continuously atmospheric pressure at 1Hz temporal resolution. In this presentation we will present some control experiments we have performed with smartphones to monitor atmospheric tides, while also using random pressure data from more than 50,000 daily users via the WeatherSignal application. We conclude that smartphones are a useful tool for studying atmospheric tides on local and global scales.

  14. A complete spherical harmonic approach to luni-solar tides

    NASA Technical Reports Server (NTRS)

    Dickman, S. R.

    1989-01-01

    In this work a spherical harmonic theory of ocean tides is presented. The theory is based on Laplace tide equations modified to include turbulence with constant eddy viscosity, linearized bottom friction, and oceanic loading and self-gravitation. Variable bathymetry is also treated in harmonic terms, and no-flow boundary conditions are applied at continental coastlines. The tide and boundary constraint equations are reduced to matrix form and solved by a weighted least-squares procedure. Five zonal luni-solar tides, ranging in period from 14 days to 18.6 yr, are investigated using the theory; such tides have typically been difficult to compute using traditional numerical approaches. The polar motion and changes in the length of day induced by these long-period tides are calculated. Tidal solutions are compared extensively with results from other tidal theories and from recent satellite and sea-level observations. The greatest limitation to accurate prediction of zonal tides - for any theory - appears to be the marginal failure of all tide theories to conserve mass globally; the use of additional mass constraints may be warranted.

  15. Energetics of global ocean tides from Geosat altimetry

    NASA Technical Reports Server (NTRS)

    Cartwright, David E.; Ray, Richard D.

    1991-01-01

    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.

  16. Impact of sea level rise on tide gate function.

    PubMed

    Walsh, Sean; Miskewitz, Robert

    2013-01-01

    Sea level rise resulting from climate change and land subsidence is expected to severely impact the duration and associated damage resulting from flooding events in tidal communities. These communities must continuously invest resources for the maintenance of existing structures and installation of new flood prevention infrastructure. Tide gates are a common flood prevention structure for low-lying communities in the tidal zone. Tide gates close during incoming tides to prevent inundation from downstream water propagating inland and open during outgoing tides to drain upland areas. Higher downstream mean sea level elevations reduce the effectiveness of tide gates by impacting the hydraulics of the system. This project developed a HEC-RAS and HEC-HMS model of an existing tide gate structure and its upland drainage area in the New Jersey Meadowlands to simulate the impact of rising mean sea level elevations on the tide gate's ability to prevent upstream flooding. Model predictions indicate that sea level rise will reduce the tide gate effectiveness resulting in longer lasting and deeper flood events. The results indicate that there is a critical point in the sea level elevation for this local area, beyond which flooding scenarios become dramatically worse and would have a significantly negative impact on the standard of living and ability to do business in one of the most densely populated areas of America.

  17. Orthogonal stack of global tide gauge sea level data

    NASA Technical Reports Server (NTRS)

    Trupin, A.; Wahr, J.

    1990-01-01

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

  18. Orthogonal stack of global tide gauge sea level data

    NASA Technical Reports Server (NTRS)

    Trupin, A.; Wahr, J.

    1990-01-01

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

  19. Ocean tide models for satellite geodesy and Earth rotation

    NASA Technical Reports Server (NTRS)

    Dickman, Steven R.

    1991-01-01

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

  20. Longitudinal and Seasonal Variation of Lunar tide strength

    NASA Astrophysics Data System (ADS)

    Yizengaw, E.; Pacheco, E. E.; Valladares, C. E.

    2012-12-01

    It has been known since many decades that lunar tide, which manifests itself as a semi-diurnal wave that precesses through all local times within one lunar month, has been identified as a significant force that can produce a notable influence on the longitudinal equatorial density distribution and equatorial electrojet (EEJ). However, there has never been a comprehensive study, except some statistical analysis using the satellite based in-situ observations, of the lunar tide effect on a global scale. This left several questions, like the longitudinal and solar flux dependence of the lunar tide, the tidal wave strength difference between new and full moon phases, remained unanswered. The proximity of the Earth/Moon system to the Sun, proximity of a New/Full Moon to one of the nodes of the lunar orbit, and the proximity of a New/Full Moon to the perigee of the lunar orbit are among the main factors that can affect the seasonal variability of lunar tide strength. With the indications of lunar tide influence on the strength of dayside EEJ, enhancing EEJ's strength shortly after new and full moon, we utilize the ground-based magnetometer fourteen years (1998 - 2012) data and investigate the various aspects of lunar tide effects on the EEJ at three different longitudinal sectors. The equatorial magnetometers located at Jicamarca for American sector, Addis Ababa for African sector, and Tirunelveli for Indian sector are used for this comprehensive study. Simultaneously, using the GPS TEC data, we examined the lunar tide impacts on the equatorial density irregularities and bubble formations at different longitudinal sectors. We found surprising strong longitudinal dependence in the lunar tide strength and its influence on EEJ and density bubble formation. Significant solar flux and seasonal dependences in lunar tide strength have also been observed at all longitudinal sectors. Finally, we investigated the lunar tide strength difference between new moon and full moon phases.

  1. TIGA Tide Gauge Data Reprocessing at GFZ

    NASA Astrophysics Data System (ADS)

    Deng, Zhiguo; Schöne, Tilo; Gendt, Gerd

    2014-05-01

    To analyse the tide gauge measurements for the purpose of global long-term sea level change research a well-defined absolute reference frame is required by oceanographic community. To create such frame the data from a global GNSS network located at or near tide gauges are processed. For analyzing the GNSS data on a preferably continuous basis the International GNSS Service (IGS) Tide Gauge Benchmark Monitoring Working Group (TIGA-WG) is responsible. As one of the TIGA Analysis Centers the German Research Centre for Geosciences (GFZ) is contributing to the IGS TIGA Reprocessing Campaign. The solutions of the TIGA Reprocessing Campaign will also contribute to 2nd IGS Data Reprocessing Campaign with GFZ IGS reprocessing solution. After the first IGS reprocessing finished in 2010 some improvements were implemented into the latest GFZ software version EPOS.P8: reference frame IGb08 based on ITRF2008, antenna calibration igs08.atx, geopotential model (EGM2008), higher-order ionospheric effects, new a priori meteorological model (GPT2), VMF mapping function, and other minor improvements. GPS data of the globally distributed tracking network of 794 stations for the time span from 1994 until end of 2012 are used for the TIGA reprocessing. To handle such large network a new processing strategy is developed and described in detail. In the TIGA reprocessing the GPS@TIGA data are processed in precise point positioning (PPP) mode to clean data using the IGS reprocessing orbit and clock products. To validate the quality of the PPP coordinate results the rates of 80 GPS@TIGA station vertical movement are estimated from the PPP results using Maximum Likelihood Estimation (MLE) method. The rates are compared with the solution of University of LaRochelle Consortium (ULR) (named ULR5). 56 of the 80 stations have a difference of the vertical velocities below 1 mm/yr. The error bars of PPP rates are significant larger than those of ULR5, which indicates large time correlated noise in

  2. Red Sea

    Atmospheric Science Data Center

    2013-04-16

    article title:  The Red Sea     View Larger Image ... 2000. Located between the East African coast and the Saudi Arabian peninsula, the Red Sea got its name because the blooms of a type of ... 2000 - The Red Sea between the East Africa coast and Saudi Arabian peninsula. project:  MISR category:  ...

  3. The anelastic equilibrium tide in exoplanetary systems

    NASA Astrophysics Data System (ADS)

    Remus, F.; Mathis, S.; Zahn, J.-P.; Lainey, V.

    2012-12-01

    Earth-like planets have anelastic mantles, whereas giant planets may have anelastic cores. As for the fluid parts of a body, the tidal dissipation of such solid regions, gravitationally perturbed by a companion body, highly depends on its internal friction, and thus on its internal structure. Therefore, modelling this kind of interaction presents a high interest to provide constraints on planet interiors, whose properties are still quite uncertain. Here, we examine the equilibrium tide in the solid central region of a planet, taking into account the presence of a fluid envelope. We discuss how the quality factor Q depends on the rheological parameters, and the size of the core. Taking plausible values for the anelastic parameters, and examinig the frequency-dependence of the solid dissipation, we show how this mechanism may compete with the dissipation in fluid layers, when applied to Jupiter- and Saturn-like planets. We also discuss the case of the icy giants Uranus and Neptune.

  4. Thermospheric energy flux of the semidiurnal tide

    NASA Astrophysics Data System (ADS)

    Groves, G. V.

    1983-10-01

    The upward energy flux of the (2,2,2) mode of atmospheric oscillation generated by water vapor and ozone radiational heating is calculated at 125 km for mean January, April, July and October conditions. The values obtained for the global mean flux lie close to 0.05 mW per sq m with a small reduction in July amounting to 13 percent of the average for the other 3 months. The effect of semidiurnal tidal heating on exospheric temperature is discussed with reference to the earlier work of Lindzen and Blake (1970) and it is concluded that the semidiurnal tide causes a relatively small increase in exospheric temperature of about 33 K.

  5. Observations of the diurnal tide from space

    NASA Technical Reports Server (NTRS)

    Hays, Paul B.; Wu, D. L.; Burrage, M. D.; Gell, D. A.; Grassl, H. J.; Lieberman, R. S.; Marshall, A. R.; Morton, Y. T.; Ortland, D. A.; Skinner, W. R.

    1994-01-01

    This study presents a climatology of mesospheric and lower-thermospheric diurnal tidal winds obtained with the High Resolution Doppler Imager (HRDI) on the Upper Atmosphere Research Satellite (UARS). The observations reveal that although tidal structures are present at all times, like the prevailing zonal winds, they exhibit significant semiannual as well as other shorter-term variations in amplitude. Results are presented for a period extending over more than one year from November 1991 to July 1993. The 1,1 diurnal tidal amplitude of the meridional component, characterized by the value at an altitude of 90 km and a latitude of 22 deg, ranges from a minimum at solstice of less than 20 m per sec to an equinox maximum of over 70 m per sec. The vertical wavelength and phase of the tide show only slight variations throughout the year, with a suggestion of semiannual variations in both.

  6. Observations of the diurnal tide from space

    NASA Technical Reports Server (NTRS)

    Hays, Paul B.; Wu, D. L.; Burrage, M. D.; Gell, D. A.; Grassl, H. J.; Lieberman, R. S.; Marshall, A. R.; Morton, Y. T.; Ortland, D. A.; Skinner, W. R.

    1994-01-01

    This study presents a climatology of mesospheric and lower-thermospheric diurnal tidal winds obtained with the High Resolution Doppler Imager (HRDI) on the Upper Atmosphere Research Satellite (UARS). The observations reveal that although tidal structures are present at all times, like the prevailing zonal winds, they exhibit significant semiannual as well as other shorter-term variations in amplitude. Results are presented for a period extending over more than one year from November 1991 to July 1993. The 1,1 diurnal tidal amplitude of the meridional component, characterized by the value at an altitude of 90 km and a latitude of 22 deg, ranges from a minimum at solstice of less than 20 m per sec to an equinox maximum of over 70 m per sec. The vertical wavelength and phase of the tide show only slight variations throughout the year, with a suggestion of semiannual variations in both.

  7. Mapping the nonstationary internal tide with satellite altimetry

    NASA Astrophysics Data System (ADS)

    Zaron, Edward D.

    2017-01-01

    Temporal variability of the internal tide has been inferred from the 23 year long combined records of the TOPEX/Poseidon, Jason-1, and Jason-2 satellite altimeters by combining harmonic analysis with an analysis of along-track wavenumber spectra of sea-surface height (SSH). Conventional harmonic analysis is first applied to estimate and remove the stationary components of the tide at each point along the reference ground tracks. The wavenumber spectrum of the residual SSH is then computed, and the variance in a neighborhood around the wavenumber of the mode-1 baroclinic M2 tide is interpreted as the sum of noise, broadband nontidal processes, and the nonstationary tide. At many sites a bump in the spectrum associated with the internal tide is noted, and an empirical model for the noise and nontidal processes is used to estimate the nonstationary semidiurnal tidal variance. The results indicate a spatially inhomogeneous pattern of tidal variability. Nonstationary tides are larger than stationary tides throughout much of the equatorial Pacific and Indian Oceans.

  8. Spectroscopic analysis of global tide gauge sea level data

    NASA Technical Reports Server (NTRS)

    Trupin, A.; Wahr, J.

    1990-01-01

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

  9. Effects of Aerosols over the Indian Ocean

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Aerosols that contain black carbon both absorb and reflect incoming sunlight. Even as these atmospheric particles reduce the amount of sunlight reaching the surface, they increase the amount of solar energy absorbed in the atmosphere, thus making it possible to both cool the surface and warm the atmosphere. The images above show satellite measurements of the region studied during the Indian Ocean Experiment (INDOEX)a vast region spanning the Arabian Sea and Bay of Bengal (west to east), and from the foot of the Himalayan Mountains, across the Indian subcontinent to the southern Indian Ocean (north to south). The Aerosol images show aerosol pollution (brownish pixels) in the lower atmosphere over the INDOEX study area, as measured by the Moderate-resolution Imaging Spectroradiometer (MODIS) aboard Terra. These were composited from March 14-21, 2001. The Albedo images show the total solar energy reflected back to space, as measured by Clouds and Earth's Radiant Energy System (CERES) aboard Terra. White pixels show high values, greens are intermediate values, and blues are low. Note how the aerosols, particularly over the ocean, increase the amount of energy reflected back to space. The Atmospheric Warming images show the absorption of the black carbon aerosols in the atmosphere. Where the aerosols are most dense, the absorption is highest. Red pixels indicate the highest levels of absorption, blues are low. The Surface Cooling images show that the aerosol particles reduce the amount of sunlight reaching the surface. Dark pixels show where the aerosols exert their cooling influence on the surface (or a high magnitude of negative radiative forcing). The bright pixels show where there is much less aerosol pollution and the incoming sunlight is relatively unaffected.

  10. Global Atmospheric Aerosol Modeling

    NASA Technical Reports Server (NTRS)

    Hendricks, Johannes; Aquila, Valentina; Righi, Mattia

    2012-01-01

    Global aerosol models are used to study the distribution and properties of atmospheric aerosol particles as well as their effects on clouds, atmospheric chemistry, radiation, and climate. The present article provides an overview of the basic concepts of global atmospheric aerosol modeling and shows some examples from a global aerosol simulation. Particular emphasis is placed on the simulation of aerosol particles and their effects within global climate models.

  11. Ocean science. Enhanced: internal tides and ocean mixing.

    PubMed

    Garrett, Chris

    2003-09-26

    Recent satellite and in situ observations have shown that at ocean ridges and other seafloor topographic features, a substantial amount of energy is transferred from the main ocean tides into "internal tides." In his Perspective, Garrett explains how these internal waves with tidal periods propagate through the density-stratified deep ocean and eventually break down into turbulence. The resulting mixing affects ocean stratification and ocean circulation. It thus influences climate as well as biological production. The energy for the internal tides is derived from the rotational energy of the Earth-Moon system changes of the length of the day and the distance to the Moon.

  12. Global Earth Response to Loading by Ocean Tide Models

    NASA Technical Reports Server (NTRS)

    Estes, R. H.; Strayer, J. M.

    1979-01-01

    Mathematical and programming techniques to numerically calculate Earth response to global semidiurnal and diurnal ocean tide models were developed. Global vertical crustal deformations were evaluated for M sub 2, S sub 2, N sub 2, K sub 2, K sub 1, O sub 1, and P sub 1 ocean tide loading, while horizontal deformations were evaluated for the M sub 2 tidal load. Tidal gravity calculations were performed for M sub 2 tidal loads, and strain tensor elements were evaluated for M sub 2 loads. The M sub 2 solution used for the ocean tide included the effects of self-gravitation and crustal loading.

  13. The self-consistent dynamic pole tide in global oceans

    NASA Technical Reports Server (NTRS)

    Dickman, S. R.

    1985-01-01

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

  14. The shaping of continental slopes by internal tides.

    PubMed

    Cacchione, D A; Pratson, L F; Ogston, A S

    2002-04-26

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

  15. The double high tide at Port Ellen: Doodson's criterion revisited

    NASA Astrophysics Data System (ADS)

    Byrne, Hannah A. M.; Mattias Green, J. A.; Bowers, David G.

    2017-07-01

    Doodson proposed a minimum criterion to predict the occurrence of double high (or double low) waters when a higher-frequency tidal harmonic is added to the semi-diurnal tide. If the phasing of the harmonic is optimal, the condition for a double high water can be written bn2/a > 1 where b is the amplitude of the higher harmonic, a is the amplitude of the semi-diurnal tide, and n is the ratio of their frequencies. Here we expand this criterion to allow for (i) a phase difference ϕ between the semi-diurnal tide and the harmonic and (ii) the fact that the double high water will disappear in the event that b/a becomes large enough for the higher harmonic to be the dominant component of the tide. This can happen, for example, at places or times where the semi-diurnal tide is very small. The revised parameter is br2/a, where r is a number generally less than n, although equal to n when ϕ = 0. The theory predicts that a double high tide will form when this parameter exceeds 1 and then disappear when it exceeds a value of order n2 and the higher harmonic becomes dominant. We test these predictions against observations at Port Ellen in the Inner Hebrides of Scotland. For most of the data set, the largest harmonic of the semi-diurnal tide is the sixth diurnal component, for which n = 3. The principal lunar and solar semi-diurnal tides are about equal at Port Ellen and so the semi-diurnal tide becomes very small twice a month at neap tides (here defined as the smallest fortnightly tidal range). A double high water forms when br2/a first exceeds a minimum value of about 1.5 as neap tides are approached and then disappears as br2/a then exceeds a second limiting value of about 10 at neap tides in agreement with the revised criterion.

  16. The self-consistent dynamic pole tide in global oceans

    NASA Technical Reports Server (NTRS)

    Dickman, S. R.

    1985-01-01

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

  17. Aerosol gels

    NASA Technical Reports Server (NTRS)

    Sorensen, Christopher M. (Inventor); Chakrabarti, Amitabha (Inventor); Dhaubhadel, Rajan (Inventor); Gerving, Corey (Inventor)

    2010-01-01

    An improved process for the production of ultralow density, high specific surface area gel products is provided which comprises providing, in an enclosed chamber, a mixture made up of small particles of material suspended in gas; the particles are then caused to aggregate in the chamber to form ramified fractal aggregate gels. The particles should have a radius (a) of up to about 50 nm and the aerosol should have a volume fraction (f.sub.v) of at least 10.sup.-4. In preferred practice, the mixture is created by a spark-induced explosion of a precursor material (e.g., a hydrocarbon) and oxygen within the chamber. New compositions of matter are disclosed having densities below 3.0 mg/cc.

  18. Seasonal variations in Pluto's atmospheric tides

    NASA Astrophysics Data System (ADS)

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

    2015-01-01

    Pluto's tenuous atmosphere exhibits remarkable seasonal change as a result of the planet's substantial obliquity and highly eccentric orbit. Over the past two decades, occultations have revealed that the atmospheric pressure on Pluto has increased substantially, perhaps by a factor as large as 2 to 4, as the planet has moved from equinox towards solstice conditions. These data have also shown variations in the strength of the dynamical activity in the atmosphere, as revealed by the varying abundance and amplitude of spikes in the occultation light curves resulting from refractive focussing by atmospheric waves. Toigo et al. (Toigo et al. [2010]. Icarus, 208, 402-411) explored the possibility that these waves are caused by solar-induced sublimation and diurnal deposition from N2 frost patches, driven by weak vertical winds resulting from the rising and sinking gas as it is released from or deposited onto the surface. Here, we extend this model to account explicitly for seasonal variations in average insolation and for the significant damping of vertical wave propagation by kinematic viscosity and thermal diffusivity (Hubbard et al. [2009]. Icarus, 204, 284-289). Damping is extremely effective in suppressing vertical propagation of waves with vertical wavelengths of a few kilometers or less, and the dominant surviving tidal modes have characteristic vertical wavelengths λ ∼ 10-13 km . We estimate the expected strength and regional characteristics of atmospheric tides over the course of Pluto's orbit for a variety of assumed spatial distributions of surface frost and atmospheric surface pressure. We compute the predicted strength of tide-induced wave activity based on the actual frost distribution observed on Pluto from Hubble Space Telescope (HST) observations (Stern et al. [1997]. Astron. J., 113, 827; Buie et al. [2010]. Astron. J., 139, 1128-1143), and compare the results to calculations for volatile transport models of Young (Young [2013]. Astrophys. J., 766

  19. Aerosol typing - key information from aerosol studies

    NASA Astrophysics Data System (ADS)

    Mona, Lucia; Kahn, Ralph; Papagiannopoulos, Nikolaos; Holzer-Popp, Thomas; Pappalardo, Gelsomina

    2016-04-01

    Aerosol typing is a key source of aerosol information from ground-based and satellite-borne instruments. Depending on the specific measurement technique, aerosol typing can be used as input for retrievals or represents an output for other applications. Typically aerosol retrievals require some a priori or external aerosol type information. The accuracy of the derived aerosol products strongly depends on the reliability of these assumptions. Different sensors can make use of different aerosol type inputs. A critical review and harmonization of these procedures could significantly reduce related uncertainties. On the other hand, satellite measurements in recent years are providing valuable information about the global distribution of aerosol types, showing for example the main source regions and typical transport paths. Climatological studies of aerosol load at global and regional scales often rely on inferred aerosol type. There is still a high degree of inhomogeneity among satellite aerosol typing schemes, which makes the use different sensor datasets in a consistent way difficult. Knowledge of the 4d aerosol type distribution at these scales is essential for understanding the impact of different aerosol sources on climate, precipitation and air quality. All this information is needed for planning upcoming aerosol emissions policies. The exchange of expertise and the communication among satellite and ground-based measurement communities is fundamental for improving long-term dataset consistency, and for reducing aerosol type distribution uncertainties. Aerosol typing has been recognized as one of its high-priority activities of the AEROSAT (International Satellite Aerosol Science Network, http://aero-sat.org/) initiative. In the AEROSAT framework, a first critical review of aerosol typing procedures has been carried out. The review underlines the high heterogeneity in many aspects: approach, nomenclature, assumed number of components and parameters used for the

  20. Energy Dissipation by Tides and Librations in Synchronous Satellites

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

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

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

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

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

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

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

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

  3. Catching the Tide: A Review of Tidal Energy Systems

    ERIC Educational Resources Information Center

    Harris, Frank

    2014-01-01

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

  4. Catching the Tide: A Review of Tidal Energy Systems

    ERIC Educational Resources Information Center

    Harris, Frank

    2014-01-01

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

  5. Increasing storm tides in New York Harbor, 1844-2013

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

  6. Future Nuisance Flooding at Boston Caused by Astronomical Tides Alone

    NASA Technical Reports Server (NTRS)

    Ray, Richard D.; Foster, Grant

    2016-01-01

    Sea level rise necessarily triggers more occurrences of minor, or nuisance, flooding events along coastlines, a fact well documented in recent studies. At some locations nuisance flooding can be brought about merely by high spring tides, independent of storms, winds, or other atmospheric conditions. Analysis of observed water levels at Boston indicates that tidal flooding began to occur there in 2011 and will become more frequent in subsequent years. A compilation of all predicted nuisance-flooding events, induced by astronomical tides alone, is presented through year 2050. The accuracy of the tide prediction is improved when several unusual properties of Gulf of Maine tides, including secular changes, are properly accounted for. Future mean sea-level rise at Boston cannot be predicted with comparable confidence, so two very different climate scenarios are adopted; both predict a large increase in the frequency and the magnitude of tidal flooding events.

  7. 2. Pilings at end of Pier 11, low tide, view ...

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

    2. Pilings at end of Pier 11, low tide, view to north. - Charlestown Navy Yard, Pier 11, Charlestown Waterfront at confluence of Little Mystic Channel & Mystic River at northernmost ent of Navy Yard, Boston, Suffolk County, MA

  8. 5. Detail of west side of pier, at low tide. ...

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

    5. Detail of west side of pier, at low tide. - Charlestown Navy Yard, Pier 10, Between Piers 9 & 11 along Mystic River on Charlestown Waterfront at eastern edge of Charlestown Navy Yard, Boston, Suffolk County, MA

  9. Internal tide convergence and mixing in a submarine canyon

    NASA Astrophysics Data System (ADS)

    Waterhouse, Amy

    2016-11-01

    Observations from Eel Canyon, located on the north coast of California, show that elevated turbulence in the full water column arises from the convergence of remotely-generated internal wave energy. The incoming semidiurnal and bottom-trapped diurnal internal tides generate complex interference patterns. The semidiurnal internal tide sets up a partly standing wave within the canyon due to reflection at the canyon head, dissipating all of its energy within the canyon. Dissipation in the near-bottom is associated with the diurnal trapped tide, while midwater isopycnal shear and strain is associated with the semidiurnal tide. Dissipation is elevated up to 600 m off the bottom, in contrast to observations over flat continental shelf where dissipation occurs closer to the topography. Slope canyons are sinks for internal wave energy and may have important influences on the global distribution of tidally-driven mixing.

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

    NASA Astrophysics Data System (ADS)

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

    2010-05-01

    Tidal gravity observations have been made recently in Algodonales (ALG) site located in the region of Andalucía, at the south of Spain. Other former gravity tide observations around this region were made in Granada and San Fernando (Vieira et al., 1983), which are 165 km northeast and 85 km southwest distant from ALG, respectively. It is planned to make shortly new gravity measurements in Melilla, which is a Spanish city placed at the other side of the Strait of Gibraltar (north of Morocco). In this way, we will dispose of an interesting gravity profile for studying the elastic response of the Earth at tidal periods in this important area of geodynamic activity. In fact, this broad region is situated around the interaction area of the Eurasia and Africa plates, where various geological structures are present, as the Alboran Sea basin, the Betico-Rifean chain, the Gulf of Cádiz and the Atlas mountain range. Also, the area is affected by occurrence of moderate magnitude earthquakes, mostly focused at shallow and intermediate depths (< 40 km) although exist records of very deep earthquakes located at the south of Granada. The two tectonic plates that interact have different movements slightly, which originates an accumulation of efforts in the fault line, that contributes to the earthquake occurrence in the zone (see e.g. Stich et al., 2006; Buforn et al., 2004; Fullea et al., 2006). The gravity observations made in ALG site, which is situated about 55km far from the coast, are considerably affected by ocean tide loading produced by the effect of the nearest Atlantic Ocean and Mediterranean Sea. Thus, the gravity effect induced by the ocean masses contributes up to 9% of the observed signal, for the main tidal constituents. The ocean loading effects have been calculated following the Farrell's (1972) procedure through the convolution between gravity Green's functions and the ocean tide distribution given by global oceanic models (TPXO7.1, FES2004, GOT00, GOT4

  11. TIDE Observations of Cusp and Cleft Multiple Ion Populations

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

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

  12. High precision tide spectroscopy. [using the superconducting gravimeter

    NASA Technical Reports Server (NTRS)

    Goodkind, J. M.

    1978-01-01

    Diurnal and long period earth tides were measured to high accuracy and precision with the superconducting gravimeter. The results provide new evidence on the geophysical questions which have been attacked through earth tide measurements in the past. In addition, they raise new questions of potential interest. Slow fluctuations in gravity of order 10 micron gal over periods of 3 to 5 months were observed and are discussed.

  13. Tides in the Martian Atmosphere as Observed by MAVEN IUVS

    NASA Astrophysics Data System (ADS)

    Lo, D.; Yelle, R. V.; Schneider, N. M.; Jain, S.; Stewart, I. F.; England, S.; Deighan, J.; Stiepen, A.; Evans, J. S.; Stevens, M. H.; Chaffin, M.; Crismani, M. M. J.; McClintock, W. E.; Clarke, J. T.; Holsclaw, G. M.; Lefèvre, F.; Jakosky, B. M.

    2015-12-01

    Driven by the diurnal solar heating, atmospheric tides are global scale oscillations in density, pressure and temperature. They are responsible for a large fraction of the variability of the atmosphere and the circulation and transport processes that stem from this variability. Here we present first observations of tides in the Martian atmosphere from the Mars Atmospheric and Volatile EvolutioN Mission (MAVEN) Imaging UltraViolet Spectrograph (IUVS). CO2+ (B2Σ+→X2Π) UV doublet emission intensities are isolated from limb profiles over the 100-190 km altitude range using a multiple linear regression procedure, and CO2 densities are then obtained by fitting a Chapman layer. Variations of the CO2 density exhibit significant persistent structure with longitudinal wavenumbers 1, 2 and 3 in a fixed local solar time frame, and such a structure points to non-migrating tides. Specific tidal modes are identified through analysis of the amplitudes and phases of the various wavenumber components and their variation with latitude. The wave-2 component is dominated by the diurnal eastward-moving DE1 tide at the equator and the diurnal stationary D0 tide at the midlatitudes. Wave-3 is dominated by the diurnal eastward-moving DE2 tide, with an unknown tide becoming dominant north of 30°N. Structure in the wave-1 component can be explained by the semidiurnal westward-moving SW1 tide. Our observations are consistent with past observations by Mars Express SPectroscopy for Investigation of Characteristics of the Atmosphere of Mars (SPICAM) [Withers et al., 2011], Mars Global Surveyor (MGS) aerobraking data [Withers et al., 2003; Moudden and Forbes, 2008] and MGS electron density measurements [Cahoy et al., 2007].

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

    NASA Technical Reports Server (NTRS)

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

    1996-01-01

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

  15. Diurnal tides in the Arctic Ocean

    NASA Technical Reports Server (NTRS)

    Kowalik, Z.; Proshutinsky, A. Y.

    1993-01-01

    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.

  16. Statistical Sampling of Tide Heights Study

    NASA Technical Reports Server (NTRS)

    2002-01-01

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

  17. Statistical Sampling of Tide Heights Study

    NASA Technical Reports Server (NTRS)

    2002-01-01

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

  18. DYNAMICAL TIDES IN ROTATING PLANETS AND STARS

    SciTech Connect

    Goodman, J.; Lackner, C.

    2009-05-10

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

  19. Probing the tides in interacting galaxy pairs

    NASA Technical Reports Server (NTRS)

    Borne, Kirk D.

    1990-01-01

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

  20. Geodynamic Effects of Ocean Tides: Progress and Problems

    NASA Technical Reports Server (NTRS)

    Richard, Ray

    1999-01-01

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

  1. Fortnightly Ocean Tides, Earth Rotation, and Mantle Anelasticity

    NASA Technical Reports Server (NTRS)

    Ray, Richard; Egbert, Gary

    2012-01-01

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

  2. Fortnightly Earth Rotation, Ocean Tides, and Mantle Anelasticity

    NASA Technical Reports Server (NTRS)

    Ray, Richard D.; Egbert, Gary D.

    2011-01-01

    Sustained accurate measurements of earth rotation are one of the prime goals of Global Geodetic Observing System (GGOS). We here concentrate on the fortnightly (Mf) tidal component of earth-rotation data to obtain new results concerning anelasticity of the mantle at this period. The study comprises three parts: (1) a new determination of the Mf component of polar motion and length-of-day from a multi-decade time series of space-geodetic data; (2) the use of the polar-motion determination as one constraint in the development of a hydrodynamic ocean model of the Mf tide; and (3) the use of these results to place new constraints on mantle anelasticity. Our model of the Mf ocean tide assimilates more than fourteen years of altimeter data from the Topex/Poseidon and Jason-1 satellites. The polar motion data, plus tide-gauge data and independent altimeter data, give useful additional information, with only the polar motion putting constraints on tidal current velocities. The resulting ocean-tide model, plus the dominant elastic body tide, leaves a small residual in observed length-of-day caused by mantle anelasticity. The inferred effective tidal 0 of the anelastic body tide is 90 and is in line with a omega-alpha frequency dependence with alpha in the range 0.2--0.3.

  3. Lunar and Solar Torques on the Oceanic Tides

    NASA Technical Reports Server (NTRS)

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

    1998-01-01

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

  4. Dynamics of the North Sea pole tide reconsidered

    NASA Technical Reports Server (NTRS)

    Wunsch, Carl

    1986-01-01

    The anomalous tide in the North Sea, driven by the Chandler wobble, is here re-examined. A previously published solution in which these 'pole tide' observations were explained as a forced co-oscillation from the deep water tide is shown to be untenable, because it is very unlikely that the deep ocean tide is anything but equilibrium. Using the same physics as in the previous solution (viscous, linear, quasi-geostrophic dynamics), it is now suggested that the only plausible explanation is that there is a coincidental resonance between the long-wavelength branch topographic Rossby wave of the North Sea and the direct driving by the pole tide potential. This resonance is not a basin-resonance, but that of a free wave driven by a travelling forcing function. Simplified models reproduce the observations in qualitative fashion. If this explanation is the correct one, then the Arctic seas north of Asia and North America appear to be likely candidates as other regions where there may be a large pole tide response and, hence, a locus of wobble dissipation. Given the difficulties of observation, the long times required, and the general instability of the dissipation calculation with the simplified analytical model, probably a numerical model will be required for further progress.

  5. Dynamic ocean-tide effects on Earth's rotation

    NASA Technical Reports Server (NTRS)

    Dickman, S. R.

    1993-01-01

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

  6. Dynamic ocean-tide effects on Earth's rotation

    NASA Technical Reports Server (NTRS)

    Dickman, S. R.

    1993-01-01

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

  7. Fortnightly Earth Rotation, Ocean Tides, and Mantle Anelasticity

    NASA Technical Reports Server (NTRS)

    Ray, Richard D.; Egbert, Gary D.

    2011-01-01

    Sustained accurate measurements of earth rotation are one of the prime goals of Global Geodetic Observing System (GGOS). We here concentrate on the fortnightly (Mf) tidal component of earth-rotation data to obtain new results concerning anelasticity of the mantle at this period. The study comprises three parts: (1) a new determination of the Mf component of polar motion and length-of-day from a multi-decade time series of space-geodetic data; (2) the use of the polar-motion determination as one constraint in the development of a hydrodynamic ocean model of the Mf tide; and (3) the use of these results to place new constraints on mantle anelasticity. Our model of the Mf ocean tide assimilates more than fourteen years of altimeter data from the Topex/Poseidon and Jason-1 satellites. The polar motion data, plus tide-gauge data and independent altimeter data, give useful additional information, with only the polar motion putting constraints on tidal current velocities. The resulting ocean-tide model, plus the dominant elastic body tide, leaves a small residual in observed length-of-day caused by mantle anelasticity. The inferred effective tidal 0 of the anelastic body tide is 90 and is in line with a omega-alpha frequency dependence with alpha in the range 0.2--0.3.

  8. Differences between mean tide level and mean sea level

    NASA Astrophysics Data System (ADS)

    Woodworth, P. L.

    2017-01-01

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

  9. Numbers, Neurons and Tides, Oh My!

    ERIC Educational Resources Information Center

    Ortiz, Mary Theresa

    2006-01-01

    Mathematical applications to biology are presented in Anatomy & Physiology, General and Marine Biology. Body measurements and anatomical terminology are integrated, and problems involving neuron conduction speed, red blood cells, hemoglobin and glomerular filtration presented. General Biology applications include trans-membrane potential and…

  10. Numbers, Neurons and Tides, Oh My!

    ERIC Educational Resources Information Center

    Ortiz, Mary Theresa

    2006-01-01

    Mathematical applications to biology are presented in Anatomy & Physiology, General and Marine Biology. Body measurements and anatomical terminology are integrated, and problems involving neuron conduction speed, red blood cells, hemoglobin and glomerular filtration presented. General Biology applications include trans-membrane potential and…

  11. Aerosol mobility size spectrometer

    DOEpatents

    Wang, Jian; Kulkarni, Pramod

    2007-11-20

    A device for measuring aerosol size distribution within a sample containing aerosol particles. The device generally includes a spectrometer housing defining an interior chamber and a camera for recording aerosol size streams exiting the chamber. The housing includes an inlet for introducing a flow medium into the chamber in a flow direction, an aerosol injection port adjacent the inlet for introducing a charged aerosol sample into the chamber, a separation section for applying an electric field to the aerosol sample across the flow direction and an outlet opposite the inlet. In the separation section, the aerosol sample becomes entrained in the flow medium and the aerosol particles within the aerosol sample are separated by size into a plurality of aerosol flow streams under the influence of the electric field. The camera is disposed adjacent the housing outlet for optically detecting a relative position of at least one aerosol flow stream exiting the outlet and for optically detecting the number of aerosol particles within the at least one aerosol flow stream.

  12. Global Ocean Tides. Part II. The Semidiurnal Principal Lunar Tide (M2), Atlas of Tidal Charts and Maps.

    DTIC Science & Technology

    1979-12-01

    tide data from Gill and Porter (1978, from deep-sea stations in the New York Bight), Wyrtki (1978, from island stations in the Pacific Ocean), Zetler...Bight by Gill and Porter (1979) verified the globally modeled, incredibly sharp tide decay (Figures a and b) across the continental shelf of less than...Part I (Schwiderski, 1978a) and the new slightly improved Tables 8M or 8N in Appendix A, which include the Gill and Porter (1978) data in interpolated

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

    SciTech Connect

    Schwiderski, E.W.

    1981-05-01

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

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

    SciTech Connect

    Schwiderski, E.W.

    1981-05-20

    In Part I of this report (AD-A060 913), a unique hydrodynamical interpolation technique was introduced, extensively tested, and evaluated in order to compute partial global ocean tides in great detail and with a high degree of accuracy. This novel method has been applied to construct the diurnal principal lunar (O1) ocean tide with a relative accuracy of better than 5 cm anywhere in the open oceans. The resulting tidal amplitudes and phases are tabulated on a 1 deg x 1 deg grid system in an atlas of 42 deg x 71 deg overlapping charts covering the whole oceanic globe. A corresponding atlas of global corange and cotidal maps is included to provide the reader with a quick general overview of the major tidal phenomena. The specifying hydrodynamical parameters of the model are listed along with quoted sources of empirical tide data, and significant tidal features are explained and discussed. The diurnal O1 ocean tide is found to resemble closely the diurnal K1 tide and qualitatively also the semidiurnal S2 and M2 tides which were presented in Parts IV, III, and II of this report, respectively (AD's A104 334, A104 333, and A084 694).

  15. AEROSOL AND GAS MEASUREMENT

    EPA Science Inventory

    Measurements provide fundamental information for evaluating and managing the impact of aerosols on air quality. Specific measurements of aerosol concentration and their physical and chemical properties are required by different users to meet different user-community needs. Befo...

  16. AEROSOL AND GAS MEASUREMENT

    EPA Science Inventory

    Measurements provide fundamental information for evaluating and managing the impact of aerosols on air quality. Specific measurements of aerosol concentration and their physical and chemical properties are required by different users to meet different user-community needs. Befo...

  17. Aerosol distribution apparatus

    DOEpatents

    Hanson, W.D.

    An apparatus for uniformly distributing an aerosol to a plurality of filters mounted in a plenum, wherein the aerosol and air are forced through a manifold system by means of a jet pump and released into the plenum through orifices in the manifold. The apparatus allows for the simultaneous aerosol-testing of all the filters in the plenum.

  18. Solid aerosol generator

    DOEpatents

    Prescott, D.S.; Schober, R.K.; Beller, J.

    1992-03-17

    An improved solid aerosol generator used to produce a gas borne stream of dry, solid particles of predetermined size and concentration is disclosed. The improved solid aerosol generator nebulizes a feed solution of known concentration with a flow of preheated gas and dries the resultant wet heated aerosol in a grounded, conical heating chamber, achieving high recovery and flow rates. 2 figs.

  19. Improved solid aerosol generator

    DOEpatents

    Prescott, D.S.; Schober, R.K.; Beller, J.

    1988-07-19

    An improved solid aerosol generator used to produce a gas borne stream of dry, solid particles of predetermined size and concentration. The improved solid aerosol generator nebulizes a feed solution of known concentration with a flow of preheated gas and dries the resultant wet heated aerosol in a grounded, conical heating chamber, achieving high recovery and flow rates. 2 figs.

  20. Solid aerosol generator

    DOEpatents

    Prescott, Donald S.; Schober, Robert K.; Beller, John

    1992-01-01

    An improved solid aerosol generator used to produce a gas borne stream of dry, solid particles of predetermined size and concentration. The improved solid aerosol generator nebulizes a feed solution of known concentration with a flow of preheated gas and dries the resultant wet heated aerosol in a grounded, conical heating chamber, achieving high recovery and flow rates.

  1. The Anelastic Equilibrium Tide in Giant Planets

    NASA Astrophysics Data System (ADS)

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

    2012-10-01

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

  2. Mapping Hurricane Inland-Storm Tides

    NASA Astrophysics Data System (ADS)

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

    2008-12-01

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

  3. Tides stir up deep Arctic heat

    NASA Astrophysics Data System (ADS)

    Green, Mattias; Rippeth, Tom; Lincoln, Ben; Lenn, Yueng; Bacon, Sheldon; Sundfjord, Arild

    2015-04-01

    The Arctic is warming at twice the rate of the rest of the planet. One of the largest sources of heat to the Arctic Ocean is the warm salty Atlantic water (AW) which enters through the Fram Strait and circulates at intermediate depth round the Arctic basin. The heat contained in the AW is sufficient to entirely melt the Arctic sea ice but is insulated from the surface by a layer of colder fresher water. Across much of the Arctic Ocean there is insufficient turbulence to drive vertical mixing, and so heat fluxes are a result of double diffusion (DD) and are consequently weak (< 0.1 W m-2). Here we present a new pan-Arctic series of direct measurements of TKE dissipation rate. The new measurements show enhanced turbulent mixing, and hence heat fluxes, over much of the continental slope around the Arctic boundary. The rate of TKE dissipation is found to increase with the bathymetric slope and vary longitudinally with the largest values to the north of Svalbard resulting in enhanced diapycnal heat fluxes over this region (20 W m-2). The observed 2-order of magnitude longitudinal variation in TKE dissipation rate correlates with the rate of dissipation of tidal energy, estimated from the local difference between the work done by the tide generating force and the tidal energy flux divergence from the TPXO8 inverse tidal solution. This correlation leads to the conclusion that the enhanced mixing observed over the continental shelf break north of Svalbard is a result of tidal processes.

  4. Semidiurnal internal tides in a Patagonian fjord

    NASA Astrophysics Data System (ADS)

    Ross, L.; Pérez-Santos, I.; Valle-Levinson, A.; Schneider, W.

    2014-12-01

    The fjords of central Chilean Patagonia (47°S) receive fresh water from both precipitation and the Baker River. This buoyancy input generates a two layer hydrographic system characterized by strong salinity stratification (∼30 g kg-1 over a depth range of 7-15 m), which favors baroclinic conditions in the fjord. Hourly current velocity profiles were collected with an acoustic Doppler current profiler (ADCP) moored at a depth of 40 m during March-April 2009, and complemented by 11 CTD profiles and hourly sea level time series. These data allowed the detection of semidiurnal internal tidal waves for the first time in this region. Wavelength and horizontal phase speeds were determined by the dynamical mode 1 for internal waves. Maximum wavelength was 52 km, travelling at a horizontal phase speed of ∼1.16 m s-1. Wavelet, spectral and empirical orthogonal function (EOF) analysis techniques applied to the echo anomaly signal and to the baroclinic velocity showed largest semidiurnal amplitudes near the pycnocline. Out of three modes obtained from the EOF analysis, two modes displayed a two- or three-layer flow structure with flow direction reversing at the pycnocline. The semidiurnal internal waves were found as fluctuations near the pycnocline in sporadic packets correlated to high discharge pulses of the Baker River (r2 = 0.77). Additionally, internal Froude number calculations at the mouth of the Baker River indicated critical flow conditions, which allowed for generation of internal waves at the plume front. These waves are separated from the river plume after internal wave phase speeds surpassed frontal speeds. This suggests that the internal waves were modulated by pulses in high river discharge rather than the interaction of barotropic tide with bathymetry (a sill). An implication of these internal waves would be to increase vertical mixing of nutrients toward the surface, through shear instabilities, which would favor primary production.

  5. Interpretation of earth tide response of three deep, confined aquifers

    SciTech Connect

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

    1984-03-10

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

  6. Red Sky with Red Mesa

    SciTech Connect

    2011-04-14

    The Red Sky/Red Mesa supercomputing platform dramatically reduces the time required to simulate complex fuel models, from 4-6 months to just 4 weeks, allowing researchers to accelerate the pace at which they can address these complex problems. Its speed also reduces the need for laboratory and field testing, allowing for energy reduction far beyond data center walls.

  7. Red Sky with Red Mesa

    ScienceCinema

    None

    2016-07-12

    The Red Sky/Red Mesa supercomputing platform dramatically reduces the time required to simulate complex fuel models, from 4-6 months to just 4 weeks, allowing researchers to accelerate the pace at which they can address these complex problems. Its speed also reduces the need for laboratory and field testing, allowing for energy reduction far beyond data center walls.

  8. Colorimetric determination of zirconium in antiperspirant aerosols.

    PubMed

    Beavin, P

    1976-07-01

    A rapid direct dilution procedure for the estimation of soluble zirconium and a fusion procedure for the determination of total zirconium (soluble and insoluble forms) in cream base concentrates prepared from antiperspirant aerosols are described. The direct dilution procedure involves extraction of soluble zirconium with HCl (55 + 45). The filtered extract is reacted with alizarin red S to form a stable colored complex which is measured spectrophotometrically. The fusion procedure involves ashing the aerosol concentrate followed by fusion of the ash with potassium pyrosulfate to form an acid-soluble melt. Zirconium is precipitated from solution as the hydroxide and washed to eliminate interfering ions, particularly sulfate. After redissolving in HCl (55 + 45) and reacting with alizarin red S, total zirconium is measured. Zirconyl chloride octahydrate, assayed gravimetrically by hydroxide precipitation and conversion to the oxide, is used as the zirconium reference standard. Concentration range of zirconium measured was 200-500 mug/100 ml. Recoveries of standard zirconium added to commercial aerosols labeled to contain aluminum and zirconyl hydroxychlorides ranged from 97 to 101% by the fusion procedure. Analysis of these aerosols by direct dilution gave generally slightly lower results than by fusion. It is recommended that the procedures be collaboratively studied after further testing of their general applicability to a variety of drugs and cosmetics.

  9. Aerosol algorithm evaluation within aerosol-CCI

    NASA Astrophysics Data System (ADS)

    Kinne, Stefan; Schulz, Michael; Griesfeller, Jan

    Properties of aerosol retrievals from space are difficult. Even data from dedicated satellite sensors face contaminations which limit the accuracy of aerosol retrieval products. Issues are the identification of complete cloud-free scenes, the need to assume aerosol compositional features in an underdetermined solution space and the requirement to characterize the background at high accuracy. Usually the development of aerosol is a slow process, requiring continuous feedback from evaluations. To demonstrate maturity, these evaluations need to cover different regions and seasons and many different aerosol properties, because aerosol composition is quite diverse and highly variable in space and time, as atmospheric aerosol lifetimes are only a few days. Three years ago the ESA Climate Change Initiative started to support aerosol retrieval efforts in order to develop aerosol retrieval products for the climate community from underutilized ESA satellite sensors. The initial focus was on retrievals of AOD (a measure for the atmospheric column amount) and of Angstrom (a proxy for aerosol size) from the ATSR and MERIS sensors on ENVISAT. The goal was to offer retrieval products that are comparable or better in accuracy than commonly used NASA products of MODIS or MISR. Fortunately, accurate reference data of ground based sun-/sky-photometry networks exist. Thus, retrieval assessments could and were conducted independently by different evaluation groups. Here, results of these evaluations for the year 2008 are summarized. The capability of these newly developed retrievals is analyzed and quantified in scores. These scores allowed a ranking of competing efforts and also allow skill comparisons of these new retrievals against existing and commonly used retrievals.

  10. On the generation and evolution of internal solitary waves in the southern Red Sea

    NASA Astrophysics Data System (ADS)

    Guo, Daquan; Zhan, Peng; Kartadikaria, Aditya; Akylas, Triantaphyllos; Hoteit, Ibrahim

    2015-04-01

    Satellite observations recently revealed the existence of trains of internal solitary waves in the southern Red Sea between 16.0°N and 16.5°N, propagating from the centre of the domain toward the continental shelf [Da silva et al., 2012]. Given the relatively weak tidal velocity in this area and their generation in the central of the domain, Da Silva suggested three possible mechanisms behind the generation of the waves, namely Resonance and disintegration of interfacial tides, Generation of interfacial tides by impinging, remotely generated internal tidal beams and for geometrically focused and amplified internal tidal beams. Tide analysis based on tide stations data and barotropic tide model in the Red Sea shows that tide is indeed very weak in the centre part of the Red Sea, but it is relatively strong in the northern and southern parts (reaching up to 66 cm/s). Together with extreme steep slopes along the deep trench, it provides favourable conditions for the generation of internal solitary in the southern Red Sea. To investigate the generation mechanisms and study the evolution of the internal waves in the off-shelf region of the southern Red Sea we have implemented a 2-D, high-resolution and non-hydrostatic configuration of the MIT general circulation model (MITgcm). Our simulations reproduce well that the generation process of the internal solitary waves. Analysis of the model's output suggests that the interaction between the topography and tidal flow with the nonlinear effect is the main mechanism behind the generation of the internal solitary waves. Sensitivity experiments suggest that neither tidal beam nor the resonance effect of the topography is important factor in this process.

  11. Downstream Amazon river dynamics under oceanic tide influence

    NASA Astrophysics Data System (ADS)

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

    2003-04-01

    Effect of oceanic tide over downstream Amazon river dynamics has been monitored between 1999 and 2001. River topography and bathymetry has been determined, tide induced water levels fluctuations have been monitored at eleven gauging stations along a 1100 km long fluvial reach, water discharges fluctuations along a tide cycle have been measured at 9 sections during low, medium and high river stages measurement campaigns. Specific measurement campaigns have been organised on northern and southern branch of Amazon river near Macapa at various river stages, including suspended sediment determination along a tide cycle. Hydrodynamic modelling has been initiated along this downstream reach. Results show an upwards propagation of oceanic tide waves along Amazon river, semi-diurnal water level fluctuations being eventually observed 1100 km from the estuary at low river stage and 530 km from the estuary at high river stage. At low river stage (November 1997) river water level at Parintins, 1100 km from the estuary, was 3.13m above mean sea level, revealing a 3 mm/km mean slope along the downstream reach of Amazon river. Mean upwards celerity of semi-diurnal tide waves is 40 km/hour with an amplitude damping and wave profile modification : as the wave moves upwards falling phase gets longer and rising phase shorter. Inversion of water discharge during a tide cycle (i.e. negative water discharge) has been observed along the Northern branch up to its divergence with Canal do Gurupa (Southern branch), 444 km from the estuary. In front of Macapa, 200 km from the estuary, Amazon water discharge during a tide cycle (16/03/2000) fluctuated from 580 000 m3/s to - 290 000 m3/s with an average 209 000 m3/s, representative of the Amazon river mean flow. Suspended sediments concentration during a tide cycle stays constant at river surface while it shows a low tide pulse at the lower part of the profile, when water velocity increase generates a sediment re-suspension. Tributaries of the

  12. Permanent components of the crust, geoid and ocean depth tides

    NASA Astrophysics Data System (ADS)

    Sun, Wenke; Sjöberg, Lars E.

    2001-04-01

    The tidal deformation caused by the luni-solar potential includes not only a periodic part, but also a time-independent part, called the permanent tide. How to deal with the tidal correction in gravimetric observations, especially the treatment of the permanent tide, has been discussed for a long time, since some practical and physical problems exist anyhow. A resolution adopted by IAG (1983) was that the permanent tidal attraction of the Moon and the Sun should be eliminated, but the permanent tidal deformation of the Earth be maintained. This is called zero gravity, and the geoid associated with it is the zero geoid. As to the crust deformation, Poutanen et al. (Poutanen, M., Vermeer, M., Mäkinen, J., 1996. The permanent tide in GPS positioning. Journal of Geodesy 70, 499-504.) suggested that co-ordinates should be reduced to the zero crust, i.e. the crust that includes the effect of the permanent tide. This research shows that horizontal components of the permanent earth tides, which are not considered in recent studies, are also important in GPS positioning and geoid determination. Since the tide-generating potential can be expanded into harmonics and divided into two parts (geodetic coefficients and the group of harmonic waves), the permanent earth tides can be easily obtained by multiplying the amplitude of the zero-frequency wavelength by the corresponding geoid geodetic coefficient. Formulas for both elastic and fluid cases are presented. Numerical results for the elastic case show that he vertical permanent crust (zero crust), geoid and ocean depth tides reach -12.0, -5.8 and 6.1 cm at the poles, and 5.9, 2.9 and -3.0 cm at the equator, respectively. The horizontal permanent crust, geoid and ocean depth tide components reach as much as 2.5, 8.7 and 6.3 cm, respectively. According to the solution of IAG (1983), the permanent vertical components are kept in GPS positioning and geoid computation. Thus, it is natural to include the horizontal components

  13. Dynamical tides and oscillations in star and planetary systems

    NASA Astrophysics Data System (ADS)

    Fuller, James Woodrow

    I investigate tidal interactions and global oscillations in various types of stellar and planetary systems, with a focus on dynamical tidal effects. Dynamical tides arise from the excitation of non-hydrostatic waves within the stellar components, with tidal dissipation resulting from the damping of the excited waves. The wave frequencies, characteristics, and dissipative qualities vary greatly in different types of stellar systems, as does the resultant tidally induced evolution. The first few chapters of this thesis focus on the excitation and dissipation of gravity waves within white dwarfs (WDs) in compact binary systems. I find that gravity waves are excited at composition gradients within the WDs, and may reach non-linear amplitudes in the outer layers of the star. At sufficiently short orbital periods, the waves are strongly non-linear and will break in the envelope of the white dwarf, producing efficient tidal dissipation. I show that this tidal dissipation will cause WDs to be nearly synchronized upon gravitational radiation-driven orbital decay. Moreover, the dissipation will heat the envelope of the WD, substantially increasing its luminosity and potentially reigniting its hydrogen shell to create a tidally induced nova-like event. I also study the tidal excitation of stellar oscillation modes in eccentric binary systems and in triple star systems, and I compare my theory with recent Kepler observations. In eccentric binary systems such as KOI-54, the tidal forcing excites stellar oscillation modes at discrete multiples of the orbital frequency. The resulting orbital and spin evolution produced by the damping of these modes may lead to resonance locking, in which a stellar oscillation mode remains nearly resonant with the tidal forcing, producing greatly enhanced tidal dissipation. In hierarchical triple star systems such as HD 181068, the orbital motion of the inner binary can excite pressure modes in a red giant tertiary component. No stable tidal

  14. Evaluation of synergized pyrethrin aerosol for control of Tribolium castaneum and Tribolium confusum (Coleoptera: Tenebrionidae)

    USDA-ARS?s Scientific Manuscript database

    Aerosol insecticides have been used in flour mill pest management programs, but there is limited information on their efficacy on different insect life stages. In this study, we evaluated the efficacy of synergized pyrethrin applied as an aerosol against eggs, larvae, pupae, and adults of the red fl...

  15. Lunar and Solar Torques on the Oceanic Tides

    NASA Technical Reports Server (NTRS)

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

    1998-01-01

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

  16. Internal tides and deep diel fades in acoustic intensity.

    PubMed

    White, Andrew W; Henyey, Frank S; Andrew, Rex K; Mercer, James A; Worcester, Peter F; Dzieciuch, Matthew A; Colosi, John A

    2016-11-01

    A mechanism is presented by which the observed acoustic intensity is made to vary due to changes in the acoustic path that are caused by internal-tide vertical fluid displacements. The position in range and depth of large-scale caustic structure is determined by the background sound-speed profile. Internal tides cause a deformation of the background profile, changing the positions of the caustic structures-which can introduce intensity changes at a distant receiver. Gradual fades in the acoustic intensity occurring over timescales similar to those of the tides were measured during a low-frequency (284-Hz) acoustic scattering experiment in the Philippine Sea in 2009 [White et al., J. Acoust. Soc. Am. 134(4), 3347-3358 (2013)]. Parabolic equation and Hamiltonian ray-tracing calculations of acoustic propagation through a plane-wave internal tide environmental model employing sound-speed profiles taken during the experiment indicate that internal tides could cause significant gradual changes in the received intensity. Furthermore, the calculations demonstrate how large-scale perturbations to the index of refraction can result in variation in the received intensity.

  17. Limiting amplitudes of fully nonlinear interfacial tides and solitons

    NASA Astrophysics Data System (ADS)

    Aguiar-González, Borja; Gerkema, Theo

    2016-08-01

    A new two-fluid layer model consisting of forced rotation-modified Boussinesq equations is derived for studying tidally generated fully nonlinear, weakly nonhydrostatic dispersive interfacial waves. This set is a generalization of the Choi-Camassa equations, extended here with forcing terms and Coriolis effects. The forcing is represented by a horizontally oscillating sill, mimicking a barotropic tidal flow over topography. Solitons are generated by a disintegration of the interfacial tide. Because of strong nonlinearity, solitons may attain a limiting table-shaped form, in accordance with soliton theory. In addition, we use a quasi-linear version of the model (i.e. including barotropic advection but linear in the baroclinic fields) to investigate the role of the initial stages of the internal tide prior to its nonlinear disintegration. Numerical solutions reveal that the internal tide then reaches a limiting amplitude under increasing barotropic forcing. In the fully nonlinear regime, numerical experiments suggest that this limiting amplitude in the underlying internal tide extends to the nonlinear case in that internal solitons formed by a disintegration of the internal tide may not reach their table-shaped form with increased forcing, but appear limited well below that state.

  18. Revisiting the pole tide for and from satellite altimetry

    NASA Astrophysics Data System (ADS)

    Desai, Shailen; Wahr, John; Beckley, Brian

    2015-12-01

    Satellite altimeter sea surface height observations include the geocentric displacements caused by the pole tide, namely the response of the solid Earth and oceans to polar motion. Most users of these data remove these effects using a model that was developed more than 20 years ago. We describe two improvements to the pole tide model for satellite altimeter measurements. Firstly, we recommend an approach that improves the model for the response of the oceans by including the effects of self-gravitation, loading, and mass conservation. Our recommended approach also specifically includes the previously ignored displacement of the solid Earth due to the load of the ocean response, and includes the effects of geocenter motion. Altogether, this improvement amplifies the modeled geocentric pole tide by 15 %, or up to 2 mm of sea surface height displacement. We validate this improvement using two decades of satellite altimeter measurements. Secondly, we recommend that the altimetry pole tide model exclude geocentric sea surface displacements resulting from the long-term drift in polar motion. The response to this particular component of polar motion requires a more rigorous approach than is used by conventional models. We show that erroneously including the response to this component of polar motion in the pole tide model impacts interpretation of regional sea level rise by ± 0.25 mm/year.

  19. Lunar and Solar Torques on the Oceanic Tides

    NASA Technical Reports Server (NTRS)

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

    1998-01-01

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

  20. Red Hill

    EPA Pesticide Factsheets

    Information about the Red Hill Bulk Fuel Storage Facility in Hawaii Administrative Order on Consent (AOC), an enforceable agreement of the Hawaii Department of Health, the Environmental Protection Agency, and the U.S. Navy -- Defense Logistics Agency.

  1. Tides and tidal stress: Applications to Europa

    NASA Astrophysics Data System (ADS)

    Hurford, Terry Anthony, Jr.

    A review of analytical techniques and documentation of previously inaccessible mathematical formulations is applied to study of Jupiter's satellite Europa. Compared with numerical codes that are commonly used to model global tidal effects, analytical models of tidal deformation give deeper insight into the mechanics of tides, and can better reveal the nature of the dependence of observable effects on key parameters. I develop analytical models for tidal deformation of multi-layered bodies. Previous studies of Europa, based on numerical computation, only to show isolated examples from parameter space. My results show a systematic dependence of tidal response on the thicknesses and material parameters of Europa's core, rocky mantle, liquid water ocean, and outer layer of ice. As in the earlier work, I restrict these studies to incompressible materials. Any set of Love numbers h 2 and k 2 which describe a planet's tidal deformation, could be fit by a range of ice thickness values, by adjusting other parameters such as mantle rigidity or core size, an important result for mission planning. Inclusion of compression into multilayer models has been addressed analytically, uncovering several issues that are not explicit in the literature. Full evaluation with compression is here restricted to a uniform sphere. A set of singularities in the classical solution, which correspond to instabilities due to self-gravity has been identified and mapped in parameter space. The analytical models of tidal response yield the stresses anywhere within the body, including on its surface. Crack patterns (such as cycloids) on Europa are probably controlled by these stresses. However, in contrast to previous studies which used a thin shell approximation of the tidal stress, I consider how other tidal models compare with the observed tectonic features. In this way the relationship between Europa's surface tectonics and the global tidal distortion can be constrained. While large-scale tidal

  2. Influence of fortnightly earth tides at Kilauea Volcano, Hawaii.

    USGS Publications Warehouse

    Dzurisin, D.

    1980-01-01

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

  3. Influence of fortnightly earth tides at Kilauea Volcano, Hawaii

    SciTech Connect

    Dzurisin, D.

    1980-11-01

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

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

    NASA Astrophysics Data System (ADS)

    Medvedev, Igor; Rabinovich, Alexander; Kulikov, Evgueni

    2014-05-01

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

  5. Global ocean tides. Part III. The semidiurnal principal solar tide (S2), atlas of tidal charts and maps. Final report

    SciTech Connect

    Schwiderski, E.W.

    1981-03-15

    In Part I of this report (AD-A060 913), a unique hydrodynamical interpolation technique was introduced, extensively tested, and evaluated in order to compute partial global ocean tides in great detail and with a high degree of accuracy. This novel method has been applied to construct the semidiurnal principal solar (S2) ocean tide with a relative accuracy of better than 5 cm anywhere in the open oceans. The resulting tidal amplitudes and phases are tabulated on a 1 deg x 1 deg grid system in an atlas of 42 deg x 71 deg overlapping charts covering the whole oceanic globe. A corresponding atlas of global corange and cotidal maps is included to provide the reader with a quick general overview of the major tidal phenomena. The specifying hydrodynamical parameters of the model are listed along with quoted sources of empirical tide data, and significant tidal features are explained and discussed. The S2 ocean tide is found to resemble closely the corresponding lunar M2 tide presented in Part II of this report (AD-A084 694).

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

    NASA Astrophysics Data System (ADS)

    MéTivier, Laurent; Conrad, Clinton P.

    2008-11-01

    Precise knowledge of Earth's body tides is crucial for correcting geodetic positioning measurements, satellite gravity surveys, and superconducting gravimeters with nanogal precision. With this aim, body tides are generally computed assuming a radially (or elliptically) stratified Earth. However, seismic tomography surveys and fluid dynamic studies show that thermal convection within Earth's mantle produces significant lateral heterogeneity exemplified by superplumes, superswells, and subducting slabs. To determine the influence of this heterogeneity on body tides, we used a tomographic model to constrain lateral variations in mantle density and rigidity. This heterogeneity drives convective flow that deflects Earth's surface and core-mantle boundaries by a few kilometers; we used a viscous flow model to constrain this dynamically supported asphericity. After verifying this complete Earth model using geoid observations, we used the spectral element method to determine how Earth's body tides are perturbed compared to a spherical Earth. We find maximum radial perturbations of surface and geoid displacements of 0.3 and 0.1 mm, respectively, and tidal gravity variations of 150 nGal. The amplitude of tidal gravity perturbations depends strongly on location and is greatest above large mantle density anomalies: e.g., large dense slabs (South America, Indonesia, Marianas), hot spots (Hawaii, Iceland), and the East African Rift. Predicted gravity perturbations are 100 times larger than the present precision of superconducting gravimeters and are comparable in magnitude to the unexplained residue observed at some gravimeter stations after tidal corrections. While this residue has been attributed to unmodeled loading from ocean tides, body tide perturbations caused by convection-induced mantle heterogeneity may contribute to this observed residue.

  7. Testing ocean tide models using GGP superconducting gravimeter observations

    NASA Astrophysics Data System (ADS)

    Baker, T.; Bos, M.

    2003-04-01

    Observations from the global network of superconducting gravimeters in the Global Geodynamics Project (GGP) are used to test 10 ocean tide models (SCHW; FES94.1, 95.2, 98, 99; CSR3.0, 4.0; TPXO.5; GOT99.2b; and NAO.99b). In addition, observations are used from selected sites with LaCoste and Romberg gravimeters with electrostatic feedback, where special attention has been given to achieving a calibration accuracy of 0.1%. In Europe, there are several superconducting gravimeter stations in a relatively small area and this can be used to advantage in testing the ocean (and body) tide models and in identifying sites with anomalous observations. At some of the superconducting gravimeter sites there are anomalies in the in-phase components of the main tidal harmonics, which are due to calibration errors of up to 0.3%. It is shown that the recent ocean tide models are in better agreement with the tidal gravity observations than were the earlier models of Schwiderski and FES94.1. However, no single ocean tide model gives completely satisfactory results in all areas of the world. For example, for M2 the TPXO.5 and NAO99b models give anomalous results in Europe, whereas the FES95.2, FES98 and FES99 models give anomalous results in China and Japan. It is shown that the observations from this improved set of tidal gravity stations will provide an important test of the new ocean tide models that will be developed in the next few years. For further details see Baker, T.F. and Bos, M.S. (2003). "Validating Earth and ocean tide models using tidal gravity measurements", Geophysical Journal International, 152.

  8. Trends in North American tides and storm surge, 1844-present

    NASA Astrophysics Data System (ADS)

    Talke, S. A.

    2016-02-01

    Using hundreds of station-years of archival tide data found in the US National Archives and digitized by students, we investigate the hypothesis that depth and other topographic changes to estuaries and tidal rivers have increased tidal constituent amplitudes and other long-waves such as storm surge and river floods. In the Columbia River Estuary, both numerical models and data suggest that channel deepening has increased the M2 tide by 10% since 1854, and resulted in faster and less dispersive flood waves. In Wilmington (NC), measurements and an idealized model show that the M2 tide has doubled since the 1880s, leading to large increases in the modeled storm surge. Analysis of other archival records from Boston (1847-present), Providence (1872-present), Philadelphia (1901-present), Norfolk (1844-present), Charleston (1850-present) , San Diego (1854-present), and San Francisco (1858-present) suggest that perturbations in harbor tidal properties are the rule, rather than the exception; in particular, comparison with nearby gauges suggests that coastal tides are much less changed over time, as measured for example by trends in overtides. A primary cause is increased channel depth, which has approximately doubled in many locations since the mid-19th century. Since depth is inversely proportional to friction in the linearized shallow water equations, increasing depth (by sea-level rise or channel deepening) has the same effect as decreasing friction. Such changes may help explain observations in New York harbor, where the elevation of the once-in 10 year storm surge has increased by nearly 0.3m since the mid-19th century. Other factors include altered river flow and resonance; for example, both analytical models and measurements suggest that the M2 tide has increased by 3% in Long Island Sound since 1892. To sum up, changes in tides can be used as an indicator of system sensitivity and can help determine whether the risk from extreme events such as storm surge will

  9. The Role of Tides in Known Multi-Planet Systems

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; DeVincenzi, D. (Technical Monitor)

    2002-01-01

    The first known extrasolar planet system, upsilon Andromedae, was discovered in 1999. The number of stars known to possess more than one planet has been growing rapidly since then. The dynamical interactions among such planets can be quite strong. These interactions can excite the orbital eccentricities of planets, even planets orbiting very close to their stars. Stellar tides can damp the eccentricities of such close-in planets, removing dynamical energy from the system and ultimately affecting the motions of all of the planets. These and other effects of tides in extrasolar multi-planet systems will be discussed.

  10. Assessment of vagotomy status with postprandial urinary alkaline tide.

    PubMed

    Longkumer, Tialiba; Parthasarathy, G; Kate, Vikram; Ananthakrishnan, N; Koner, B C

    2009-01-01

    This study was carried out to assess whether the postprandial urinary alkaline tide, as a marker for the completeness of vagotomy, is dependent on the nature of the test meal, whether it is affected by proton pump inhibitor therapy, and whether it is reliable. The postprandial urinary alkaline tide (PUAT) pattern was prospectively assessed in three different study groups and one control group of healthy volunteers. The three study groups were as follows; A (n = 20) i.e. the Proton Pump Inhibitor (PPI) Group; B (n = 25) i.e. the Truncal Vagotomy (TV) Group; and C (n = 5) i.e. the Recurrent Ulcer (RU) Group. Urinary pH was measured by a pocket digital pH meter. Postprandial urinary alkaline tide in the control group was significantly higher compared to the fasting levels. Liquid diet did not elicit a significant urinary alkaline tide response. There was a statistically significant fall in both fasting urinary pH (5.34 +/- 0.70 vs. 4.80 +/- 0.61, p = 0.031) and the postprandial alkaline tide (6.99 +/- 0.79 vs. 4.94 +/- 0.63, p = 0.0001) after taking proton pump inhibitors. In the truncal vagotomy and gastrojejunostomy group it was found that there was a significant fall in both the mean fasting (5.28 +/- 0.58, vs. 4.92 +/- 0.66, p = 0.032) and the postprandial urinary pH (6.29 +/- 0.92 vs. 5.09 +/- 0.73, p = 0.0001) following surgery. This study establishes that simple measurement of the urinary pH before and after a standard test meal can be used as an accurate routine test for the completion of vagotomy. It also showed that proton pump inhibitors abolish the alkaline tide and therefore must be discontinued before measuring the alkaline tide. Liquid test meal was not effective in eliciting an alkaline tide as compared to a solid meal.

  11. Radar wind profiler observations of solar semidiurnal atmospheric tides

    SciTech Connect

    Whiteman, C.D.; Bian, X.

    1995-04-15

    Semidiurnal solar tides in the mid-latitude troposhphere are investigated using harmonic analysis of 404 MHz radar profiler wind data obtained from a wide longitude zone in the U.S. The tides are apparent above a 1000-m-deep surface layer and increase in amplitude with height, attaining speeds of 0.5-0.7 m/s at 5-7 km. Observed wind characteristics agree well with tidal characteristics obtained with a dynamical model driven by observed global semidiurnal horizontal pressure gradients. 10 refs., 6 figs., 1 tab.

  12. The Role of Tides in Known Multi-Planet Systems

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; DeVincenzi, D. (Technical Monitor)

    2002-01-01

    The first known extrasolar planet system, upsilon Andromedae, was discovered in 1999. The number of stars known to possess more than one planet has been growing rapidly since then. The dynamical interactions among such planets can be quite strong. These interactions can excite the orbital eccentricities of planets, even planets orbiting very close to their stars. Stellar tides can damp the eccentricities of such close-in planets, removing dynamical energy from the system and ultimately affecting the motions of all of the planets. These and other effects of tides in extrasolar multi-planet systems will be discussed.

  13. Middle and upper thermosphere density structures due to nonmigrating tides

    NASA Astrophysics Data System (ADS)

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

    2012-11-01

    Density measurements from the SETA satellites near 200 km during 1982-1984, and the CHAMP and GRACE satellites between 350 and 550 km during 2002-2009, are used to investigate longitudinal structures in density due to nonmigrating tides, and to evaluate performance of the recently-created Climatological Tidal Model of the Thermosphere (CTMT). Amplitudes for the diurnal and semidiurnal tidal components fall roughly in the range of 4-10%. Diurnal tides at middle and low latitudes are often characterized by wave-3 and/or wave-4 structures, consistent with the presence of the eastward-propagating diurnal tides with zonal wave numbers s = 2 and s = 3 (DE2 and DE3, respectively) and with expected seasonal variability based on previous works. Semidiurnal structures often reflect the presence of the eastward-propagating tide with s = 2 (SE2), which gives rise to wave-4 structures that have a more antisymmetric relationship between N. and S. hemispheres. Similarities in structures between different years underscore the fact that the thermosphere is subject to repeatable and reproducible forcing by upward-propagating tides, but there are also occasions where considerable departures from climatology occur. Wave-2 structures at high latitudes likely contain signatures of the eastward-propagating diurnal tide with s = 1 (DE1) and the zonally-symmetric (s = 0) semidiurnal oscillation (S0) propagating upwards from below, but these and other waves that produce wave-2 can also be forced in-situ by high-latitude processes. The CTMT captures the salient features of the observations at middle and low latitudes, although with lower amplitudes that are likely due to phase cancelation effects resulting from averaging over multiple years (2002-2006). We propose that some discrepancies between the CTMT and our observational results may be associated with wave components arising in-situ in the thermosphere as the result of nonlinear tide-tide interactions and plasma neutral interactions

  14. A coupled oscillator model of shelf and ocean tides

    NASA Astrophysics Data System (ADS)

    Arbic, Brian K.; Garrett, Chris

    2010-04-01

    The resonances of tides in the coupled open ocean and shelf are modeled by a mechanical analogue consisting of a damped driven larger mass and spring (the open-ocean) connected to a damped smaller mass and spring (the shelf). When both masses are near resonance, the addition of even a very small mass can significantly affect the oscillations of the larger mass. The influence of the shelf is largest if the shelf is resonant with weak friction. In particular, an increase of friction on a near-resonant shelf can, perhaps surprisingly, lead to an increase in ocean tides. On the other hand, a shelf with large friction has little effect on ocean tides. Comparison of the model predictions with results from numerical models of tides during the ice ages, when lower sea levels led to a much reduced areal extent of shelves, suggests that the predicted larger tidal dissipation then is related to the ocean basins being close to resonance. New numerical simulations with a forward global tide model are used to test expectations from the mechanical analogue. Setting friction to unrealistically large values in Hudson Strait yields larger North Atlantic M2 amplitudes, very similar to those seen in a simulation with the Hudson Strait blocked off. Thus, as anticipated, a shelf with very large friction is nearly equivalent in its effect on the open ocean to the removal of the shelf altogether. Setting friction in shallow waters throughout the globe to unrealistically large values yields even larger open ocean tidal amplitudes, similar to those found in simulations of ice-age tides. It thus appears that larger modeled tides during the ice ages can be a consequence of enhanced friction in shallower water on the shelf in glacial times as well as a reduced shelf area then. Single oscillator and coupled oscillator models for global tides show that the maximum extractable power for human use is a fraction of the present dissipation rate, which is itself a fraction of global human power

  15. Storm Surge and Tide Interaction: A Complete Paradigm

    NASA Astrophysics Data System (ADS)

    Horsburgh, K.

    2014-12-01

    Estimates show that in 2005, in the largest 136 coastal cities, there were 40 million people and 3,000 billion of assets exposed to 1 in 100 year coastal flood events. Mean sea level rise will increase this exposure to 150 million people and 35,000 billion of assets by 2070. Any further change in the statistics of flood frequency or severity would impact severely on economic and social systems. It is therefore crucial to understand the physical drivers of extreme storm surges, and to have confidence in datasets used for extreme sea level statistics. Much previous research has focussed on the process of tide-surge interaction, and it is now widely accepted that the physical basis of tide-surge interaction is that a phase shift of the tidal signal represents the effect of the surge on the tide. The second aspect of interaction is that shallow water momentum considerations imply that differing tidal states should modulate surge generation: wind stress should have greater surge-generating potential on lower tides. We present results from a storm surge model of the European shelf that demonstrate that tidal range does have an effect on the surges generated. The cycle-integrated effects of wind stress (i.e. the skew surge) are greater when tidal range is low. Our results contradict the absence of any such correlation in tide gauge records. This suggests that whilst the modulating effect of the tide on the skew surge (the time-independent difference between peak prediction and observations) is significant, the difference between individual storms is dominant. This implies that forecasting systems must predict salient detail of the most intense storms. A further implication is that flood forecasting models need to simulate tides with acceptable accuracy at all coastal locations. We extend our model analysis to show that the same modulation of storm surges (by tidal conditions) applies to tropical cyclones. We conduct simulations using a mature operational storm surge model

  16. Storm surge and tide interaction: a complete paradigm

    NASA Astrophysics Data System (ADS)

    Horsburgh, Kevin; Williams, Jane; Proctor, Robert

    2014-05-01

    Globally, 200 million people live on coastal floodplains and about 1 trillion worth of assets lie within 1 metre of mean sea level. Any change in the statistics of flood frequency or severity would impact on economic and social systems. It is therefore crucial to understand the physical drivers of extreme storm surges, and to have confidence in datasets used for extreme sea level statistics. Much previous research has focussed on the process of tide-surge interaction, and it is now widely accepted that the physical basis of tide-surge interaction is that a phase shift of the tidal signal represents the effect of the surge on the tide. The second aspect of interaction is that shallow water momentum considerations imply that differing tidal states should modulate surge generation: wind stress should have greater surge-generating potential on lower tides. This has been shown previously by analytical models but not as yet confirmed by fully non-linear models of the continental shelf. We present results from an operational model of the European shelf that demonstrate that tidal range does have an effect on the surges generated. The cycle-integrated effects of wind stress (i.e. the skew surge) are generally greater when tidal range is low. Our results contradict the absence of any such correlation observed in the complete record of UK tide gauge data. This suggests that whilst the modulating effect of the tide on the skew surge (the time-independent difference between peak prediction and observations) is significant, the difference between individual storms is dominant. This implies that forecasting systems must predict salient detail of the most intense storms. A further implication is that operational models need to simulate tides with acceptable accuracy at all coastal locations. We extend our model analysis to show that the same modulation of storm surges (by tidal conditions) applies to tropical cyclones. We conduct simulations using a mature operational storm surge

  17. Tide Corrections for Coastal Altimetry: Status and Prospects

    NASA Technical Reports Server (NTRS)

    Ray, Richard D.; Egbert, Gary D.

    2008-01-01

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

  18. Turning the Tide Against Aids | NIH MedlinePlus the Magazine

    MedlinePlus

    ... turn Javascript on. Feature: Turning the Tide Against AIDS Turning the Tide Against AIDS Past Issues / Fall 2012 Table of Contents A ... What is the current state of the HIV/AIDS epidemic? Globally, more than 34 million people are ...

  19. Green tide disaster monitoring system based on multi-source data

    NASA Astrophysics Data System (ADS)

    Shang, Weitao; Gao, Zhiqiang; Jiang, Xiaopeng; Liu, Chaoshun; Gao, Wei

    2016-09-01

    This paper builds a green tide disaster monitoring system based on remote sensing monitoring platform, UAV (Unmanned aerial vehicle) monitoring platform and ship monitoring platform. The system aims at multi-faceted monitoring green tide disasters with remote sensing data, UAV data and ship monitoring data. With this system, the author has continuously monitored the green tide outbreak of Chinese Yellow Sea in 2016. Research conclusions were achieved as follows. The system can quickly get spatial distribution information of green tide disaster, obtain high-resolution remote sensing data and field verification data of key monitoring areas; It can cover the shortage of a single data source by green tide monitoring, significantly improve time resolution and spatial resolution of green tide monitoring data, thus providing data support for dynamic monitoring of green tide; The system can provide data support for the prevention and control of green tide in three different scales.

  20. Tides at the east coast of Lanzarote Island

    NASA Astrophysics Data System (ADS)

    Benavent, M.; Arnoso, J.; Vélez, E. J.

    2012-04-01

    The main goal of this work is the study of the ocean tides at the east coast of Lanzarote (Canary Islands). We have analyzed time series of tide gauge and bottom pressure observations available in the region and we have made a further comparative validation with recent global and local ocean tide models. Lanzarote island shows singular features, with regard its volcanic structure and geomorphological properties and, also, concerning the characteristics of the ocean tides in the surrounding waters. For this reason, this region experiences a great interest in Geodesy and Geodynamics. Particularly, an accurate modelization of the ocean tides is of great importance to correct with high accuracy the effect of the ocean over the multiple geodetic measurements that are being carried out in the Geodynamic Laboratory of Lanzarote, LGL (Vieira et al., 1991; 2006). Furthermore, the analysis of tide gauge and bottom pressure records in this area is of great importance to investigate sea level variations, to evaluate and quantify the causes of these changes and the possible correlation with vertical movements of the Earth's crust. The time series of sea level and bottom pressure data considered in this work are obtained at two different locations of the island and, in each of them, using several sensors at different periods of time. First location is Jameos del Agua (JA) station, which belongs to the LGL. This station is placed in the open ocean, 200 meters distant from the northeastern coast of the island and at 8 meters depth. The observations have been carried out using 3 bottom pressure sensors (Aanderaa WLR7, SAIV TD301A and Aqualogger 210PT) at different periods of time (spanning a total of six years). Second location is Arrecife (AR) station, which is 23 km south of JA station. In this case, the sea level data come from a float tide gauge belonging to the Instituto Español de Oceanografía, installed at the beginning of the loading bay, and a radar tide gauge from the

  1. Imaging aerosol viscosity

    NASA Astrophysics Data System (ADS)

    Pope, Francis; Athanasiadis, Thanos; Botchway, Stan; Davdison, Nicholas; Fitzgerald, Clare; Gallimore, Peter; Hosny, Neveen; Kalberer, Markus; Kuimova, Marina; Vysniauskas, Aurimas; Ward, Andy

    2017-04-01

    Organic aerosol particles play major roles in atmospheric chemistry, climate, and public health. Aerosol particle viscosity is important since it can determine the ability of chemical species such as oxidants, organics or water to diffuse into the particle bulk. Recent measurements indicate that OA may be present in highly viscous states; however, diffusion rates of small molecules such as water appear not to be limited by these high viscosities. We have developed a technique for measuring viscosity that allows for the imaging of aerosol viscosity in micron sized aerosols through use of fluorescence lifetime imaging of viscosity sensitive dyes which are also known as 'molecular rotors'. These rotors can be introduced into laboratory generated aerosol by adding minute quantities of the rotor to aerosol precursor prior to aerosolization. Real world aerosols can also be studied by doping them in situ with the rotors. The doping is achieved through generation of ultrafine aerosol particles that contain the rotors; the ultrafine aerosol particles deliver the rotors to the aerosol of interest via impaction and coagulation. This work has been conducted both on aerosols deposited on microscope coverslips and on particles that are levitated in their true aerosol phase through the use of a bespoke optical trap developed at the Central Laser Facility. The technique allows for the direct observation of kinetic barriers caused by high viscosity and low diffusivity in aerosol particles. The technique is non-destructive thereby allowing for multiple experiments to be carried out on the same sample. It can dynamically quantify and track viscosity changes during atmospherically relevant processes such oxidation and hygroscopic growth (1). This presentation will focus on the oxidation of aerosol particles composed of unsaturated and saturated organic species. It will discuss how the type of oxidant, oxidation rate and the composition of the oxidized products affect the time

  2. The Tidal Dynamics and Energy Balance of the Red Sea

    NASA Astrophysics Data System (ADS)

    Pugh, David T.; Abualnaja, Yasser O.; NP, Mohammedali; Eltaib, Elfatih B.

    2014-05-01

    The semidiurnal tides of the Red Sea have been mapped as a classic half-wavelength standing wave. Because of the earth's rotation, the pattern is actually composed of an ingoing Kelvin wave, with maximum amplitude found in the northern eastern side along the Saudi Arabia coastline, and a reflected south-going Kelvin wave along the southern African coastline. The result is tidal rotation around a central amphidrome; this amphidrome, because of energy losses in the reflected wave, is nearer to the African side close to Port Sudan. The movements of this amphidrome can be mapped through a spring-neap tidal cycle to show how the tidal energy is dissipated through the Red Sea. There are suggestions that that Red Sea tides are entirely due to direct internal tidal gravitational astronomical forcing; this is an alternative to the model of energy flux from the Gulf of Aden tides in the Indian Ocean, through the entrance at Bab el Mandeb. These alternative energy sources will be investigated in the project.

  3. Overview of Aerosol Distribution

    NASA Technical Reports Server (NTRS)

    Kaufman, Yoram

    2005-01-01

    Our knowledge of atmospheric aerosols (smoke, pollution, dust or sea salt particles, small enough to be suspended in the air), their evolution, composition, variability in space and time and interaction with clouds and precipitation is still lacking despite decades of research. Understanding the global aerosol system is fundamental for progress in climate change and hydrological cycle research. While a single instrument was used to demonstrate 50 years ago that the global CO2 levels are rising, posing threat of global warming, we need an array of satellites and field measurements coupled with chemical transport models to understand the global aerosol system. This complexity of the aerosol problem results from their short lifetime (1 week) and variable chemical composition. A new generation of satellites provides exciting opportunities to measure the global distribution of aerosols, distinguishing natural from anthropogenic aerosol and measuring their interaction with clouds and climate. I shall discuss these topics and application of the data to air quality monitoring.

  4. Overview of Aerosol Distribution

    NASA Technical Reports Server (NTRS)

    Kaufman, Yoram

    2005-01-01

    Our knowledge of atmospheric aerosols (smoke, pollution, dust or sea salt particles, small enough to be suspended in the air), their evolution, composition, variability in space and time and interaction with clouds and precipitation is still lacking despite decades of research. Understanding the global aerosol system is fundamental for progress in climate change and hydrological cycle research. While a single instrument was used to demonstrate 50 years ago that the global CO2 levels are rising, posing threat of global warming, we need an array of satellites and field measurements coupled with chemical transport models to understand the global aerosol system. This complexity of the aerosol problem results from their short lifetime (1 week) and variable chemical composition. A new generation of satellites provides exciting opportunities to measure the global distribution of aerosols, distinguishing natural from anthropogenic aerosol and measuring their interaction with clouds and climate. I shall discuss these topics and application of the data to air quality monitoring.

  5. Aerosol, radiation, and climate

    NASA Technical Reports Server (NTRS)

    Pollack, J. B.

    1983-01-01

    Airborne, spaceborne, and ground-based measurements are used to study the radiative and climatic effects of aerosols. The data, which are modelled with a hierarchy of radiation and climate models, and their implications are summarized. Consideration is given to volcanic aerosols, polar stratospheric clouds, and the Arctic haze. It is shown that several types of aerosols (volcanic particles and the Arctic haze) cause significant alterations to the radiation budget of the regions where they are located.

  6. Tides. Marine Science Curriculum Aid No. 5. Sea Grant Report 80-2.

    ERIC Educational Resources Information Center

    McDonald, Judy

    This manual, developed for use in Alaskan secondary schools, is one of a continuing series designed to provide basic information about the marine environment and Alaskan marine resources. The first part of the manual presents information about tides, focusing on: the nature of tides; cause of tides; factors related to tidal movement; types of…

  7. Impacts of exotic mangroves and mangrove control on tide pool fish assemblages

    Treesearch

    Richard A. MacKenzie; Cailtin L. Kryss

    2013-01-01

    Fish were sampled from tide pools in Hawaii to determine how exotic mangroves Rhizophora mangle and the use of herbicides to chemically eradicate them are impacting tide pool fish assemblages. Ecological parameters were compared among mangrove-invaded, native vegetated, and non-vegetated tide pools before and after mangroves had been chemically...

  8. Understanding the variability of an extreme storm tide along a coastline

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

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

  9. 75 FR 20371 - Certificate of Alternative Compliance for the Offshore Supply Vessel LEBOUEF TIDE

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-19

    ... SECURITY Coast Guard Certificate of Alternative Compliance for the Offshore Supply Vessel LEBOUEF TIDE... Alternative Compliance was issued for the offshore supply vessel LEBOUEF TIDE as required by 33 U.S.C. 1605(c... LEBOUEF TIDE. The horizontal distance between the forward and aft masthead lights may be 25 -9 ....

  10. Radiative Effects of Aerosols

    NASA Technical Reports Server (NTRS)

    Valero, Francisco P. J.

    1997-01-01

    During the Atlantic Stratocumulus Transition Experiment (ASTEX) in June 1992, two descents in cloud-free regions allowed comparison of the change in aerosol optical depth as determined by an onboard total-direct-diffuse radiometer (TDDR) to the change calculated from measured size resolved aerosol microphysics and chemistry. Both profiles included pollution haze layer from Europe but the second also included the effect of a Saharan dust layer above the haze. The separate contributions of supermicrometer (coarse) and submicrometer (fine) aerosol were determined and thermal analysis of the pollution haze indicated that the fine aerosol was composed primarily of a sulfate/water mixture with a refractory soot-like core.

  11. 5. View of Sterling Creek Marsh at low tide showing ...

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

    5. View of Sterling Creek Marsh at low tide showing the lining of the bottom of the marsh, with dam in background - Richmond Hill Plantation, Sterling Creek Marsh, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  12. Exploring Marine Science through the University of Delaware's TIDE camp

    NASA Astrophysics Data System (ADS)

    Veron, D. E.; Newton, F. A.; Veron, F.; Trembanis, A. C.; Miller, D. C.

    2012-12-01

    For the past five years, the University of Delaware has offered a two-week, residential, summer camp to rising sophomores, juniors, and seniors who are interested in marine science. The camp, named TIDE (Taking an Interest in Delaware's Estuary) camp, is designed to introduce students to the breadth of marine science while providing them with a college experience. Campers participate in a variety of academic activities which include classroom, laboratory, and field experiences, as well as numerous social activities. Two unique features of this small, focused camp is the large number of university faculty that are involved, and the ability of students to participate in ongoing research projects. At various times students have participated in fish and dolphin counts, AUV deployment, wind-wave tank experiments, coastal water and beach studies, and ROV activities. In addition, each year campers have participated in a local service project. Through communication with former TIDE participants, it is clear that this two-week, formative experience plays a large role in students choice of major when entering college.2012 Tide Camp - Salt marsh in southern Delaware 2012 Tide Camp - Field trip on a small boat

  13. How Tidal Forces Cause Ocean Tides in the Equilibrium Theory

    ERIC Educational Resources Information Center

    Ng, Chiu-king

    2015-01-01

    We analyse why it is erroneous to think that a tidal bulge is formed by pulling the water surface directly up by a local vertical tidal force. In fact, ocean tides are caused by the global effect of the horizontal components of the tidal forces.

  14. Oceanic Hot Spots - Internal Tides in the Global Ocean

    DTIC Science & Technology

    2012-01-01

    Moderate Resolution Imaging Spectroradiometer (MODIS) showing internal waves propagat- ing toward Palawan Island in the Sulu Sea between Borneo and...image obtained by the Moderate Resolution Imag- ing Spectroradiometer (MODIS) over the Sulu Sea near Borneo . The surface tide sloshing through the

  15. Devonian tides: a driver for the evolution of terrestrial vertebrates?

    NASA Astrophysics Data System (ADS)

    Byrne, Hannah; Green, Mattias

    2017-04-01

    The Devonian era saw one of the biggest evolutionary phases for Vertebrates, branching off from lobed-finned fish (sarcopterygians) to develop limbs enabling the transition from a marine to a terrestrial life. It has recently been suggested that the evolutionary pressure came from unusually large semidiurnal tides at the time, leaving individuals stranded in rock pools for up to a fortnight. It was therefore advantageous if the organism had some form of mechanism to transition between these pools, and so brought about the development of limbs. Here, we simulate the tides from the Devonian using the dedicated tidal model OTIS and a series of Devonian plate reconstructions. The reconstructions span the entire Devonian era (410 Mya - 340 Mya) and comprise of Classic and Alternative models of the Devonian. The results shows that as Gondwana and Laurasia collided, the ocean basin between them did go through several resonances, indeed producing unusually large local tides and associated spring-neap cycles. This not only support the idea that tides produced the pressure for the evolution of tetrapods, but can also have contributed to the vast areas of anoxia implied by the sediments from the period which led to mass extinction events during the late Devonian.

  16. How Tidal Forces Cause Ocean Tides in the Equilibrium Theory

    ERIC Educational Resources Information Center

    Ng, Chiu-king

    2015-01-01

    We analyse why it is erroneous to think that a tidal bulge is formed by pulling the water surface directly up by a local vertical tidal force. In fact, ocean tides are caused by the global effect of the horizontal components of the tidal forces.

  17. Wind Stress Forcing of the North Sea "Pole Tide"

    NASA Technical Reports Server (NTRS)

    OConnor, William P.; Chao, Benjamin Fong; Zheng, Dawei; Au, Andrew Y.

    1998-01-01

    We conducted numerical simulations of the wind-forcing of the sea level variations in the North Sea using a barotropic ocean model with realistic geography, bathymetry, and boundary conditions, to examine the forcing of the 14-month "pole tide" which is known to be strong along the Denmark- Netherlands coast. The simulation input is the monthly-mean surface wind stress field from the National Centers for Environmental Prediction (NCEP) reanalysis for the 40-year period 1958-1997. The output sea level response was then compared with 10 coastal tide gauge records from the Permanent Service for Mean Sea Level (PSMSL). Besides the strong seasonal variations, several prominent quasi-periodicities exist at around 7 years, 3 years, 14 months, 9 months, and 6.5 months. Correlation and spectral analyses show remarkable agreement between the model output and the observations, particularly in the 14-month, or Chandler period band. The latter indicates that the enhanced pole tide found in the North Sea along the Denmark-Netherlands coast is actually the coastal setup response to wind stress forcing with a periodicity of 14 months. We find no need to invoke a geophysical explanation involving resonance-enhancement of pole tide in the North Sea to explain the observations.

  18. Oceanography for Divers: Waves, Tides, and Currents. Diver Education Series.

    ERIC Educational Resources Information Center

    Somers, Lee H.

    To dive safely, it is suggested that the diver have a working knowledge of waves, tides, currents, and water quality. Lack of understanding and respect for ocean currents and surf can be of serious consequence to the diver. This paper on the diving environment is designed to provide the diver with a general understanding of the physical…

  19. Testing Ocean Tide Models Using Superconducting Gravimeter Observations

    NASA Astrophysics Data System (ADS)

    Baker, T. F.; Bos, M. S.

    2002-12-01

    Observations from the global network of superconducting gravimeters in the Global Geodynamics Project (GGP) are used to test 10 recent ocean tide models. In addition, observations are used from selected sites with LaCoste and Romberg gravimeters with electrostatic feedback, where special attention has been given to achieving a calibration accuracy of 0.1%. At some superconducting gravimeter sites there are anomalies in the in-phase components of the main tidal harmonics, which are due to calibration errors of up to 0.3%. It is shown that the recent ocean tide models are in better agreement with the tidal gravity observations than were the earlier models of Schwiderski and FES94.1. However, no single ocean tide model gives completely satisfactory results in all areas of the world. For example, for M2 the TPXO.5 and NAO99b models give anomalous results in Europe, whereas the FES95.2, FES98 and FES99 models give anomalous results in China and Japan. It is shown that the observations from this improved set of tidal gravity stations will provide an important test of the new ocean tide models that will be developed in the next few years.

  20. 1620 Geographos and 433 Eros: Shaped by Planetary Tides

    NASA Technical Reports Server (NTRS)

    Bottke, William F., Jr.; Richardson, Derek C.; Michel, Patrick; Love, Stanley G.

    1997-01-01

    Until recently, most asteroids were thought to be solid bodies whose shapes were determined largely by collisions with other asteroids. It now seems that many asteroids are little more than rubble piles, held together by self-gravity; this means that their shapes may be strongly affected by tides during close encounters with planets.

  1. Assessing the accuracy of predicted ocean tide loading displacement values

    NASA Astrophysics Data System (ADS)

    Penna, N. T.; Bos, M. S.; Baker, T. F.; Scherneck, H.-G.

    2008-12-01

    The accuracy of ocean tide loading (OTL) displacement values has long been assumed to be dominated by errors in the ocean tide models used, with errors due to the convolution scheme used considered very small (2-5%). However, this paper shows that much larger convolution errors can arise at sites within approximately 150 km of the coastline, depending on the method used to refine the discrete regularly spaced grid cells of the ocean tide model to better fit the coastline closest to the site of interest. If the local water mass redistribution approach is implemented, as used in the OLFG/OLMPP software recommended in the IERS 2003 conventions, OTL height displacement errors of up to around 20% can arise, depending on the ocean tide model used. Bilinear interpolation only, as used in the SPOTL and CARGA softwares for example, is shown from extensive global and regional comparisons of OTL displacement values derived from the different methods and softwares to be more appropriate. This is verified using GPS observations. The coastal refinement approach used in the OLFG/OLMPP software was therefore changed in August 2007 to use bilinear interpolation only. It is shown that with this change, OTL displacement values computed using OLFG/OLMPP, SPOTL and CARGA invariably agree to the millimetre level for coastal sites, and better than 0.2 mm for sites more than about 150 km inland.

  2. 7. Detail, at low tide (10 ft. mht), north side ...

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

    7. Detail, at low tide (-10 ft. mht), north side of railway substructure, showing deck cantilevered beyond platform, and vertical timber connection configuration. - Charlestown Navy Yard, Marine Railway, Between Piers 2 & 3, on Charlestown Waterfront at west end of Navy Yard, Boston, Suffolk County, MA

  3. 21. A LOW TIDE VIEW OF THE NORTH TRAINING WALL'S ...

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

    21. A LOW TIDE VIEW OF THE NORTH TRAINING WALL'S CHANNEL FACING STONEWORK, LOOKING EAST FROM THE POINT WHERE MODERN RIPRAP BEGINS TO COVER THE WALL, ABOUT 2,000 FEET FROM THE WEST END. - Oakland Harbor Training Walls, Mouth of Federal Channel to Inner Harbor, Oakland, Alameda County, CA

  4. 3. Detail of west side of pier at low tide ...

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

    3. Detail of west side of pier at low tide revealing twin pilings with block spacers, usually submerged; view to northeast. - Charlestown Navy Yard, Pier 9, Between Piers 8 & 10, along Mystic River on Charlestown Waterfront at eastern edge of Navy Yard, Boston, Suffolk County, MA

  5. GENERAL VIEW LOOKING EAST ACROSS THE RIVER AT LOW TIDE, ...

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

    GENERAL VIEW LOOKING EAST ACROSS THE RIVER AT LOW TIDE, FROM JUST BELOW THE CIDER PRESS. NOTE THE FOUNDATIONS AND PILINGS OF A FORMER BOATHOUSE STRUCTURE VISIBLE IN THE FOREGROUND - John Bartram House & Garden, 54th Street & Lindbergh Boulevard, Philadelphia, Philadelphia County, PA

  6. On Measurements of the Tide at Churchill, Hudson Bay

    NASA Technical Reports Server (NTRS)

    Ray, Richard D.

    2016-01-01

    Since the late 1990s the semi-diurnal tide at Churchill, on the western shore of Hudson Bay, has been decreasing in amplitude, with M(sub 2) amplitudes falling from approximately 154 cm in 1998 to 146 cm in 2012 and 142 cm in 2014. There has been a corresponding small increase in phase lag. Mean low water, decreasing throughout most of the twentieth century, has levelled off. Although the tidal changes could reflect merely a malfunctioning tide gauge, the fact that there are no other measurements in the region and the possibility that the tide is revealing important environmental changes calls for serious investigation. Satellite altimeter measurements of the tide in Hudson Bay are complicated by the seasonal ice cover; at most locations less than 40% of satellite passes return valid ocean heights and even those can be impacted by errors from sea ice. Because the combined TOPEX/Poseidon, Jason-1, and Jason-2 time series is more than 23 years long, it is now possible to obtain sufficient data at crossover locations near Churchill to search for tidal changes. The satellites sense no changes in M(sub 2) that are comparable to the changes seen at the Churchill gauge. The changes appear to be localized to the harbour, or to the Churchill River, or to the gauge itself.

  7. Child dermal sediment loads following play in a tide flat.

    PubMed

    Shoaf, Marley B; Shirai, Jeffry H; Kedan, Golan; Schaum, John; Kissel, John C

    2005-09-01

    Dermal contact with sediment is sometimes identified as a pathway of concern in risk assessments. Dermal exposure to sediment is poorly characterized and exposure assessors may rely on default soil adherence values. The purpose of this study was to obtain sediment adherence data for a genuine exposure scenario, child play in a tide flat. This study reports direct measurements of sediment loadings on five body parts (face, forearms, hands, lower legs and feet) after play in a tide flat. Each of nine subjects participated in two timed sessions and pre- and post-activity sediment loading data were collected. Geometric mean (geometric standard deviation) dermal loadings (mg/cm(2)) on the face, forearm, hands, lower legs and feet for the combined sessions were 0.04 (2.9), 0.17 (3.1), 0.49 (8.2), 0.70 (3.6) and 21 (1.9), respectively. Participants' parents completed questionnaires regarding their child's typical activity patterns during tide flat play, exposure frequency and duration, clothing choices, bathing practices and clothes laundering. Data presented in this paper supplement very limited prior adherence data for sediment contact scenarios. Results will be useful to risk assessors considering exposure scenarios involving child activities at a coastal shoreline or tide flat.

  8. Aerosol distribution and efficacy in a commercial food warehouse

    USDA-ARS?s Scientific Manuscript database

    A series of field trials were conducted in a commercial field storage facility to evaluate exposure of stored-product insects to aerosol formulations of pyrethrin and the insect growth regulator methoprene. When adults of Tribolium castaneum (Herbst), the red flour beetle, and Tribolium confusum (Ja...

  9. Earth tides of an ellipsoidal, inelastic, and laterally heterogeneous Earth

    NASA Astrophysics Data System (ADS)

    Kim, T.; Shibuya, K.

    2012-12-01

    We used five stations covering a range of latitudes from 60°N to 70°S: METSÄHOVI, STRASBOURG, SUTHERLAND, CANBERRA, and SYOWA with Superconducting Gravimeter with sufficiently high-resolution data available for durations of at least five years to validate theoretical estimation based on an existing method. For the Earth model, we selected the model of Dehant et al. (1999) to validate the latitude dependency and inelasticity of gravimetric factor. We also used the model of Métivier and Conrad (2008) to validate the lateral heterogeneity of gravity observation. For the correction of ocean loading effect, we tested recent four global ocean tide models (TPXO7-atlas, EOT11a, DTU10, and HAMTIDE11a) as well as old ocean tide models. We estimated the misfit between the observed loading effect and the modeled ocean loading effect for the three main waves (O1, K1, and M2) at each station. Anomalous discrepancies at METSÄHOVI and SYOWA based on old ocean tide models were diminished by the use of recent ocean tide models. Gravimetric factors for K1, corrected using optimum recent ocean tide models, showed the possibility of obtaining parameters conforming to the prediction curve of model of inelastic non-hydrostatic Earth. Gravimetric factors corrected using optimum ocean tide models at METSÄHOVI, STRASBOURG, and CANBERRA showed tendencies towards the theoretical values for latitude dependence. However, at SUTHERLAND and SYOWA, large offsets from theoretical values were observed. These stations show the remaining misfits, 0.0733 and 0.0847 microGal, respectively. We think the portion of the anomaly could not be explained by the perturbation from the mantle convection, because the amplitude of gravity perturbation at these stations is very small. For example, at SUTHERLAND, the final residual for K1 band is 85 nanoGal but gravity perturbation by lateral heterogeneity is just ~0.81 nanoGal: Gravity perturbations up to 120 nanoGal for all bands come from mostly in Indonesia

  10. Nanoscale welding aerosol sensing based on whispering gallery modes in a cylindrical silica resonator

    PubMed Central

    Lee, Aram; Mills, Thomas; Xu, Yong

    2015-01-01

    We report an experimental technique where one uses a standard silica fiber as a cylindrical whispering gallery mode (WGM) resonator to sense airborne nanoscale aerosols produced by electric arc welding. We find that the accumulation of aerosols on the resonator surface induces a measurable red-shift in resonance frequency, and establish an empirical relation that links the magnitude of resonance shift with the amount of aerosol deposition. The WGM quality factors, by contrast, do not decrease significantly, even for samples with a large percentage of surface area covered by aerosols. Our experimental results are discussed and compared with existing literature on WGM-based nanoparticle sensing. PMID:25837078

  11. Nonmigrating diurnal tides in the equatorial middle atmosphere

    SciTech Connect

    Lieberman, R.S.

    1992-01-01

    Data from the Nimbus 7 Limb Infrared Monitor of the Stratosphere (LIMS) are used to analyze the diurnal tides in the middle atmosphere. A novel aspect of this study is the emphasis on the relative importance of the nonmigrating components. These modes display a high degree of temporal variability during the LIMS observing period, and contribute substantially to the diurnal signal in wind and temperature. Their observed vertical phase variations are variable; however there is evidence for upward energy propagation. It has long been hypothesized that nonmigrating tides are driven by the diurnally-varying zonally asymmetric tropospheric heating constituents. This premise is examined by employing a linear tidal model to simulate the response of the atmosphere to realistic tidal drives. These quantities are calculated from the NCAR Community Climate Model. The large-scale CCM2 diurnal surface pressure, OLR and hydrology are well simulated under July and January conditions. The CCM2 diurnal fields of short-wave radiative, convective and diffusive PBL heating are used as input to a linear tidal model with Newtonian cooling. This model successfully reproduces many observed features of the migrating and nonmigrating diurnal surface pressure tides at low latitudes. In the middle atmosphere, tropospheric solar heating is the dominant source of the migrating tide. The zonal means and eastward migrating wavenumber one components are also associated with radiative heating. The eastward migrating wavenumber three pattern is strongly linked to the dry and moist convective heating as well. The observed eastward migrating tides are harder to simulate, due in part to the failure of the linear model to incorporate the dissipative effects to which they are prone.

  12. Interannual and Intraseasonal Variability of the Diurnal Tide

    NASA Astrophysics Data System (ADS)

    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

    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).

  13. Standing internal tides in the Tasman Sea observed by gliders

    NASA Astrophysics Data System (ADS)

    Johnston, Shaun

    2015-04-01

    Low-mode internal tides are generated at tall submarine ridges, propagate across the open ocean with little attenuation, and possibly shoal at or reflect from distant continental slopes. Such a semidiurnal internal tide beam emanates from the Macquarie Ridge, south of New Zealand, crosses the Tasman Sea, and impinges on the Tasmanian slope. The beam is identified in previous altimetric observations and modelling. Spatial surveys by two autonomous underwater gliders with maximum profile depths of 500-1000 m estimate the mode-1 incident and reflected flux magnitudes to be 1-2 kW/m. Uncertainties on the glider-measured mode-1 flux magnitude are 40-90% (arising from both a limited profiling depth and angular resolution of the gliders' survey pattern, which is treated as an internal wave antenna). The direction of the incident internal tides are consistent with altimetry and modelling, while the reflected tide is consistent with specular reflection from a straight coastline. Refraction by the offshore East Tasman Plateau may focus the incident waves on the steepest part of the slope. The steep slope reflects almost all of the incident energy flux into a reflected wave to form a standing wave. Reflectivity is 0.8-1 at the steep slope in the beam (i.e., the area with greatest energy density), with the remaining fraction (0-0.2) of the incident energy either lost to mixing at this steep slope or transmitted onto the shelf. Starting from the slope and moving offshore by a half wavelength, kinetic energy density displays a node-antinode-node structure, while potential energy density shows an antinode-node-antinode structure. Observations of standing internal tides are few in number.

  14. Environmental Chemistry and Chemical Ecology of "Green Tide" Seaweed Blooms.

    PubMed

    Van Alstyne, Kathryn L; Nelson, Timothy A; Ridgway, Richard L

    2015-09-01

    Green tides are large growths or accumulations of green seaweeds that have been increasing in magnitude and frequency around the world. Because green tides consist of vast biomasses of algae in a limited area and are often seasonal or episodic, they go through periods of rapid growth in which they take up large amounts of nutrients and dissolved gases and generate bioactive natural products that may be stored in the plants, released into the environment, or broken down during decomposition. As a result of the use and production of inorganic and organic compounds, the algae in these blooms can have detrimental impacts on other organisms. Here, we review some of the effects that green tides have on the chemistry of seawater and the effects of the natural products that they produce. As blooms are developing and expanding, algae in green tides take up inorganic nutrients, such as nitrate and ortho-phosphate, which can limit their availability to other photosynthetic organisms. Their uptake of dissolved inorganic carbon for use in photosynthesis can cause localized spikes in the pH of seawater during the day with concomitant drops in the pH at night when the algae are respiring. Many of the algae that form green-tide blooms produce allelopathic compounds, which are metabolites that affect other species. The best documented allelopathic compounds include dimethylsulfoniopropionate (DMSP), dopamine, and reactive oxygen species (ROS) and their breakdown products. DMSP and dopamine are involved in defenses against herbivores. Dopamine and ROS are released into seawater where they can be allelopathic or toxic to other organisms. Thus, these macroalgal blooms can have harmful effects on nearby organisms by altering concentrations of nutrients and dissolved gas in seawater and by producing and releasing allelopathic or toxic compounds.

  15. Fortnightly atmospheric tides forced by spring and neap tides in coastal waters

    PubMed Central

    Iwasaki, Shinsuke; Isobe, Atsuhiko; Miyao, Yasuyuki

    2015-01-01

    The influence of sea surface temperature (SST) on atmospheric processes over the open ocean has been well documented. However, atmospheric responses to SST in coastal waters are poorly understood. Oceanic stratification (and consequently, SST) in coastal waters largely depends on the fortnightly spring–neap tidal cycle, because of variations in vertical tidal mixing. Here we investigate how changes in SST during the fortnightly tidal cycle affect the lower-level atmosphere over the Seto Inland Sea, Japan. We use a combination of in situ measurements, satellite observations and a regional atmospheric model. We find that the SST in summer shows cool (warm) anomalies over most of the inland sea during spring (neap) tides. Additionally, surface air temperature is positively correlated with the SST as it varies during the fortnightly tidal cycle. Moreover, the fortnightly spring–neap cycle also influences the surface wind speed because the atmospheric boundary layer becomes stabilized or destabilized in response to the difference between air temperature and SST. PMID:25984948

  16. Fortnightly atmospheric tides forced by spring and neap tides in coastal waters

    NASA Astrophysics Data System (ADS)

    Iwasaki, Shinsuke; Isobe, Atsuhiko; Miyao, Yasuyuki

    2015-05-01

    The influence of sea surface temperature (SST) on atmospheric processes over the open ocean has been well documented. However, atmospheric responses to SST in coastal waters are poorly understood. Oceanic stratification (and consequently, SST) in coastal waters largely depends on the fortnightly spring-neap tidal cycle, because of variations in vertical tidal mixing. Here we investigate how changes in SST during the fortnightly tidal cycle affect the lower-level atmosphere over the Seto Inland Sea, Japan. We use a combination of in situ measurements, satellite observations and a regional atmospheric model. We find that the SST in summer shows cool (warm) anomalies over most of the inland sea during spring (neap) tides. Additionally, surface air temperature is positively correlated with the SST as it varies during the fortnightly tidal cycle. Moreover, the fortnightly spring-neap cycle also influences the surface wind speed because the atmospheric boundary layer becomes stabilized or destabilized in response to the difference between air temperature and SST.

  17. Fortnightly atmospheric tides forced by spring and neap tides in coastal waters.

    PubMed

    Iwasaki, Shinsuke; Isobe, Atsuhiko; Miyao, Yasuyuki

    2015-05-18

    The influence of sea surface temperature (SST) on atmospheric processes over the open ocean has been well documented. However, atmospheric responses to SST in coastal waters are poorly understood. Oceanic stratification (and consequently, SST) in coastal waters largely depends on the fortnightly spring-neap tidal cycle, because of variations in vertical tidal mixing. Here we investigate how changes in SST during the fortnightly tidal cycle affect the lower-level atmosphere over the Seto Inland Sea, Japan. We use a combination of in situ measurements, satellite observations and a regional atmospheric model. We find that the SST in summer shows cool (warm) anomalies over most of the inland sea during spring (neap) tides. Additionally, surface air temperature is positively correlated with the SST as it varies during the fortnightly tidal cycle. Moreover, the fortnightly spring-neap cycle also influences the surface wind speed because the atmospheric boundary layer becomes stabilized or destabilized in response to the difference between air temperature and SST.

  18. Titan Ice and Dust Experiment (TIDE): Detection and Analysis of Compounds of Interest to Astrobiology in the Lower Atmosphere and Surface of Titan

    NASA Technical Reports Server (NTRS)

    Kojiro, Daniel R.; Holland Paul M.; Stimac, Robert M.; Kaye, William J.; Takeruchi, Noreshige

    2004-01-01

    The Titan Orbiter Aerorover Mission (TOAM) is a proposed concept for the Solar System Exploration Visions Mission, Titan Explorer, a follow-on to the Cassini-Huygens mission. TOAM would use a Titan polar orbiter and a lighter-than-air aerorover to investigate the surface and atmosphere of Titan. Astrobiology issues will be addressed though TOAM investigations including, for example: Distribution and composition of organics (atmospheric, aerosol, surface); Organic chemical processes, their chemical context and energy sources; and Seasonal variations and interactions of the atmosphere and surface. The TIDE instrument will perform in-situ analyses to obtain comprehensive and sensitive molecular and elemental assays of volatile organics in the atmosphere, oceans and surface. TIDE chemical analyses are conducted by a Gas Chromatograph-Ion Mobility Spectrometer (GC-IMS). This TIDE GC-IMS was a component of the mini-Cometary Ice and Dust Experiment (mini-CIDEX) developed for the chemical analysis of a cometary environment. Both the GC and helium IMS of mini-CIDEX have been further developed to better meet the analytical and operational requirements of the TOAM. application. A Micro-ElectroMechanical System (MEMS) GC and Mini-Cell helium IMS are under development to replace their respective mini-CIDEX components, providing similar or advanced analytical capabilities.

  19. Titan Ice and Dust Experiment (TIDE): Detection and Analysis of Compounds of Interest to Astrobiology in the Lower Atmosphere and Surface of Titan

    NASA Technical Reports Server (NTRS)

    Kojiro, Daniel R.; Holland Paul M.; Stimac, Robert M.; Kaye, William J.; Takeruchi, Noreshige

    2004-01-01

    The Titan Orbiter Aerorover Mission (TOAM) is a proposed concept for the Solar System Exploration Visions Mission, Titan Explorer, a follow-on to the Cassini-Huygens mission. TOAM would use a Titan polar orbiter and a lighter-than-air aerorover to investigate the surface and atmosphere of Titan. Astrobiology issues will be addressed though TOAM investigations including, for example: Distribution and composition of organics (atmospheric, aerosol, surface); Organic chemical processes, their chemical context and energy sources; and Seasonal variations and interactions of the atmosphere and surface. The TIDE instrument will perform in-situ analyses to obtain comprehensive and sensitive molecular and elemental assays of volatile organics in the atmosphere, oceans and surface. TIDE chemical analyses are conducted by a Gas Chromatograph-Ion Mobility Spectrometer (GC-IMS). This TIDE GC-IMS was a component of the mini-Cometary Ice and Dust Experiment (mini-CIDEX) developed for the chemical analysis of a cometary environment. Both the GC and helium IMS of mini-CIDEX have been further developed to better meet the analytical and operational requirements of the TOAM. application. A Micro-ElectroMechanical System (MEMS) GC and Mini-Cell helium IMS are under development to replace their respective mini-CIDEX components, providing similar or advanced analytical capabilities.

  20. Transmissometer versus sun photometer measurements of the aerosol optical properties

    NASA Astrophysics Data System (ADS)

    Kusmierczyk-Michulec, Jolanta; Van Eijk, Alexander M. J.; Moerman, M. M.; Cohen, L. H.; de Jong, A.; Fritz, P.

    2008-08-01

    Atmospheric aerosol particles affect the Earth's radiative balance both in the cloud-free and the cloudy atmosphere. The direct effect of aerosols is related with scattering and absorption of solar radiation, and as a consequence, reduction of the amount of radiation reaching the surface. The best parameter that quantifies this effect is the aerosol extinction, which can be derived from vertical, as well as, horizontal measurements. The purpose of this paper is to compare the aerosol optical properties registered by two types of instruments. The first is a standard 5-wavelength hand-held sun photometer yielding the vertical column extinction, the second a 7-wavelength transmissometer developed at TNO. This multi-band transmissometer provides horizontal, path-integrated transmission data at 7 wavelengths within the visible/infra red spectral range. The data used in the comparison were collected during an experiment near Scripps Pier in La Jolla near San Diego, in November 2006.

  1. Cellular component of lavage fluid from broilers with normal versus aerosol-primed airways

    USDA-ARS?s Scientific Manuscript database

    Previously we reported that intratracheal administration of lipopolysaccharide (LPS) elicits pulmonary hypertension (PH) in broilers reared under commercial conditions, in broilers reared in environmental chambers and pre-treated with aerosolized red food colorant # 3 and propylene glycol (Red#3+PG)...

  2. Global ocean tide models on the eve of Topex/Poseidon

    NASA Technical Reports Server (NTRS)

    Ray, Richard D.

    1993-01-01

    Some existing global ocean tide models that can provide tide corrections to Topex/Poseidon altimeter data are described. Emphasis is given to the Schwiderski and Cartwright-Ray models, as these are the most comprehensive, highest resolution models, but other models that will soon appear are mentioned. Differences between models for M2 often exceed 10 cm over vast stretches of the ocean. Comparisons to 80 selected pelagic and island gauge measurements indicate the Schwiderski model is more accurate for the major solar tides, Cartwright-Ray for the major lunar tides. The adequacy of available tide models for studying basin-scale motions is probably marginal at best.

  3. Global ocean tide models on the eve of Topex/Poseidon

    NASA Technical Reports Server (NTRS)

    Ray, Richard D.

    1993-01-01

    Some existing global ocean tide models that can provide tide corrections to Topex/Poseidon altimeter data are described. Emphasis is given to the Schwiderski and Cartwright-Ray models, as these are the most comprehensive, highest resolution models, but other models that will soon appear are mentioned. Differences between models for M2 often exceed 10 cm over vast stretches of the ocean. Comparisons to 80 selected pelagic and island gauge measurements indicate the Schwiderski model is more accurate for the major solar tides, Cartwright-Ray for the major lunar tides. The adequacy of available tide models for studying basin-scale motions is probably marginal at best.

  4. The colors of biomass burning aerosols in the atmosphere

    PubMed Central

    Liu, Chao; Chung, Chul Eddy; Zhang, Feng; Yin, Yan

    2016-01-01

    Biomass burning aerosols mainly consist of black carbon (BC) and organic aerosols (OAs), and some of OAs are brown carbon (BrC). This study simulates the colors of BrC, BC and their mixture with scattering OAs in the ambient atmosphere by using a combination of light scattering simulations, a two-stream radiative transfer model and a RGB (Red, Green, Blue) color model. We find that both BCs and tar balls (a class of BrC) appear brownish at small particle sizes and blackish at large sizes. This is because the aerosol absorption Ångström exponent (AAE) largely controls the color and larger particles give smaller AAE values. At realistic size distributions, BCs look more blackish than tar balls, but still exhibit some brown color. However, when the absorptance of aerosol layer at green wavelength becomes larger than approximately 0.8, all biomass burning aerosols look blackish. The colors for mixture of purely scattering and absorptive carbonaceous aerosol layers in the atmosphere are also investigated. We suggest that the brownishness of biomass burning aerosols indicates the amount of BC/BrC as well as the ratio of BC to BrC. PMID:27306230

  5. The colors of biomass burning aerosols in the atmosphere

    NASA Astrophysics Data System (ADS)

    Liu, Chao; Chung, Chul Eddy; Zhang, Feng; Yin, Yan

    2016-06-01

    Biomass burning aerosols mainly consist of black carbon (BC) and organic aerosols (OAs), and some of OAs are brown carbon (BrC). This study simulates the colors of BrC, BC and their mixture with scattering OAs in the ambient atmosphere by using a combination of light scattering simulations, a two-stream radiative transfer model and a RGB (Red, Green, Blue) color model. We find that both BCs and tar balls (a class of BrC) appear brownish at small particle sizes and blackish at large sizes. This is because the aerosol absorption Ångström exponent (AAE) largely controls the color and larger particles give smaller AAE values. At realistic size distributions, BCs look more blackish than tar balls, but still exhibit some brown color. However, when the absorptance of aerosol layer at green wavelength becomes larger than approximately 0.8, all biomass burning aerosols look blackish. The colors for mixture of purely scattering and absorptive carbonaceous aerosol layers in the atmosphere are also investigated. We suggest that the brownishness of biomass burning aerosols indicates the amount of BC/BrC as well as the ratio of BC to BrC.

  6. The colors of biomass burning aerosols in the atmosphere.

    PubMed

    Liu, Chao; Chung, Chul Eddy; Zhang, Feng; Yin, Yan

    2016-06-16

    Biomass burning aerosols mainly consist of black carbon (BC) and organic aerosols (OAs), and some of OAs are brown carbon (BrC). This study simulates the colors of BrC, BC and their mixture with scattering OAs in the ambient atmosphere by using a combination of light scattering simulations, a two-stream radiative transfer model and a RGB (Red, Green, Blue) color model. We find that both BCs and tar balls (a class of BrC) appear brownish at small particle sizes and blackish at large sizes. This is because the aerosol absorption Ångström exponent (AAE) largely controls the color and larger particles give smaller AAE values. At realistic size distributions, BCs look more blackish than tar balls, but still exhibit some brown color. However, when the absorptance of aerosol layer at green wavelength becomes larger than approximately 0.8, all biomass burning aerosols look blackish. The colors for mixture of purely scattering and absorptive carbonaceous aerosol layers in the atmosphere are also investigated. We suggest that the brownishness of biomass burning aerosols indicates the amount of BC/BrC as well as the ratio of BC to BrC.

  7. Merging the SAGE II and OSIRIS Stratospheric Aerosol Records

    NASA Astrophysics Data System (ADS)

    Rieger, Landon; Bourassa, Adam; Degenstein, Doug

    2016-04-01

    The Optical Spectrograph and InfraRed Imaging System (OSIRIS) instrument on the Odin satellite, launched in 2001 and currently operational, measures limb-scattered sunlight from which profiles of stratospheric aerosol extinction at 750nm are retrieved. The Stratospheric Aerosol and Gas (SAGE) II instrument was operational from 1985 to 2005, and provided aerosol extinction at several visible and near infrared wavelengths. This work compares the SAGE II and OSIRIS aerosol extinction measurements during the four years of instrument overlap by interpolating the SAGE II data to 750nm using the 525 and 1020nm channels. Agreement is generally favourable in the tropics and mid-latitudes with differences less than 10% for the majority of the aerosol layer. However, near the UTLS and outside of the tropics agreement is poorer and reasons for this are investigated. Comparisons between the OSIRIS and SAGE II aerosol extinction measurements at 750nm are used to develop a merged aerosol climatology as a function of time, latitude and altitude at the native SAGE II wavelength of 525nm. Error due to assumptions in the OSIRIS retrieval and wavelength conversion are explored through simulation studies over a range of particle size distributions and is found to be approximately 20% for the majority of low-to-moderate volcanic loading conditions and OSIRIS geometries. Other sources of error such as cloud contamination in the UTLS are also explored.

  8. Portable Aerosol Contaminant Extractor

    DOEpatents

    Carlson, Duane C.; DeGange, John J.; Cable-Dunlap, Paula

    2005-11-15

    A compact, portable, aerosol contaminant extractor having ionization and collection sections through which ambient air may be drawn at a nominal rate so that aerosol particles ionized in the ionization section may be collected on charged plate in the collection section, the charged plate being readily removed for analyses of the particles collected thereon.

  9. Direct Aerosol Forcing Uncertainty

    DOE Data Explorer

    Mccomiskey, Allison

    2008-01-15

    Understanding sources of uncertainty in aerosol direct radiative forcing (DRF), the difference in a given radiative flux component with and without aerosol, is essential to quantifying changes in Earth's radiation budget. We examine the uncertainty in DRF due to measurement uncertainty in the quantities on which it depends: aerosol optical depth, single scattering albedo, asymmetry parameter, solar geometry, and surface albedo. Direct radiative forcing at the top of the atmosphere and at the surface as well as sensitivities, the changes in DRF in response to unit changes in individual aerosol or surface properties, are calculated at three locations representing distinct aerosol types and radiative environments. The uncertainty in DRF associated with a given property is computed as the product of the sensitivity and typical measurement uncertainty in the respective aerosol or surface property. Sensitivity and uncertainty values permit estimation of total uncertainty in calculated DRF and identification of properties that most limit accuracy in estimating forcing. Total uncertainties in modeled local diurnally averaged forcing range from 0.2 to 1.3 W m-2 (42 to 20%) depending on location (from tropical to polar sites), solar zenith angle, surface reflectance, aerosol type, and aerosol optical depth. The largest contributor to total uncertainty in DRF is usually single scattering albedo; however decreasing measurement uncertainties for any property would increase accuracy in DRF. Comparison of two radiative transfer models suggests the contribution of modeling error is small compared to the total uncertainty although comparable to uncertainty arising from some individual properties.

  10. Ganges valley aerosol experiment.

    SciTech Connect

    Kotamarthi, V.R.; Satheesh, S.K.

    2011-08-01

    In June 2011, the Ganges Valley Aerosol Experiment (GVAX) began in the Ganges Valley region of India. The objective of this field campaign is to obtain measurements of clouds, precipitation, and complex aerosols to study their impact on cloud formation and monsoon activity in the region.

  11. Analyzing the Modeled Tidal Signal in the Bab El Mandeb Strait and Adjacent Red Sea and Gulf of Aden Waters

    NASA Astrophysics Data System (ADS)

    Guillory, R. N. B.

    2014-12-01

    The tidal forces that dominate the Bab el Mandeb region are influenced by both the generally semi-diurnal tides in the Red Sea and mixed tides in the Gulf of Aden. Also, the tidal ranges are much greater in the Gulf of Aden (~ 2 m) than in the Red Sea (< 1m), which further complicates the tidal signal in Bab el Mandeb Strait. The Red Sea Regional Navy Coastal Model (NCOM), which includes the entire Red Sea, and the western part of the Gulf of Aden at a 1 km resolution, will be evaluated on how well it replicates the tidal signal described in literature and historical observations. In addition, the model will be compared to available temperature/salinity in situ profiles. NCOM incorporates the Oregon State University Tide Model, which should allow the ocean model to accurately reflect the transitional tides in the Bab el Mandeb Strait. Preliminary estimates indicate that the model replicates the overall circulation pattern seen in literature and the fact that there are higher tidal amplitudes in the Gulf of Aden than in the Red Sea. Approved for Public Release, Distribution Unlimited

  12. Simulation and video animation of canal flushing created by a tide gate

    USGS Publications Warehouse

    Schoellhamer, David H.

    1988-01-01

    A tide-gate algorithm was added to a one-dimensional unsteady flow model that was calibrated, verified, and used to determine the locations of as many as five tide gates that would maximize flushing in two canal systems. Results from the flow model were used to run a branched Lagrangian transport model to simulate the flushing of a conservative constituent from the canal systems both with and without tide gates. A tide gate produces a part-time riverine flow through the canal system that improves flushing along the flow path created by the tide gate. Flushing with no tide gates and with a single optimally located tide gate are shown with a video animation.

  13. Numerical Internal Tide Scattering, Diffraction, and Dissipation on the Tasman Continental Slope

    NASA Astrophysics Data System (ADS)

    Klymak, J. M.; Simmons, H. L.; MacKinnon, J. A.; Alford, M. H.; Pinkel, R.

    2014-12-01

    Internal tides generated at steep topography tend to propagate far from their source with little local mixing. Where does this energy dissipate? One candidate is via reflection on continental slopes. The upcoming Tasmanian Internal Tide Experiment aims to look at the reflection of internal tide generated near New Zealand and track its reflection from the Tasmanian Continental Slope. Here we consider numerical studies to track the propagation of the internal tide onto this slope and its dissipation. We find a strong interference patterns sets up, as expected from a reflecting tide. The pattern is complicated by the ``Tasman Rise'' positioned near the center of the incoming internal tide beam, causing a diffraction pattern to focus and defocus the tide along the slope. Dissipative mechanisms on the slope include turbulent lee waves from small cross-slope ridges, and along-slope lee-waves trapped and breaking in corrugations in the slope.

  14. Digital holographic PTV analysis of the motile performance of the red-tides alga ``Cochlodinium polykrikoides''

    NASA Astrophysics Data System (ADS)

    Sohn, M.; Lee, S.; Choi, Y.; Seo, G.; Kang, Y.; Kang, Y.

    2009-11-01

    The outbreaks of Cochlodinium polykrikoides causes severe damages to fisheries in Korea and Japan. C. polykrikoides actively makes chains in its exponential and stationary growth phase. The role of the chain formation has not been clearly known yet. In the present study, the motility characteristics of C. polykrikoides was investigated using 3D digital holographic PTV technique. The moving trajectories and average velocities of the single and multi-chained C. polykrikoides were compared to investigate the effect of the chain formation on the motile performance. Most of the multi-chained C. polykrikoides exhibited zigzag or helical trajectory and the translational velocity of the 4-chained C. polykrikoides was at least two-times larger than the single one.

  15. Diel vertical distributions of the red tide dinoflagellate Alexandrium fundyense in the Gulf of Maine

    NASA Astrophysics Data System (ADS)

    Townsend, David W.; Bennett, Stephanie L.; Thomas, Maura A.

    2005-09-01

    Two 24-h experiments, designed to test whether the toxic dinoflagellate Alexandrium fundyense exhibited significant changes in vertical distribution, were performed in offshore waters of the Gulf of Maine in June 2000. Standard hydrocasts with a CTD/carousel water sampler package were made hourly on-station while following a drogue set at 25 m depth. Continuous measurements of T, S, and chlorophyll fluorescence were made on each down cast, and discrete water samples were collected at 5-m intervals from 55 m depth to the surface on the up cast, for analyses of extracted phytoplankton chlorophyll, inorganic nutrients and cell densities of Alexandrium In the first experiment we observed a bimodal vertical distribution of cells, with relatively high cell densities near the surface (<15 m depth) and a second peak of relatively high cell densities at depths between 25 and 40 m, coincident with the depth of the pycnocline and nitricline. Internal waves of 10-15 m amplitude appeared to exert control over the depth distribution of the deep population. Approximately 12 h into the first experiment, a relatively warm surface water mass with low Alexandrium cell densities intruded over the drogue station, leaving only the deep population. In the second experiment overall cell densities of Alexandrium were much lower, but again we observed initially a bimodal depth distribution of cells. As in the first experiment, the surface population effectively disappeared after a few hours, leaving only the deep population; in this case, however, there was some evidence of an initial downward movement of the surface population prior to its complete disappearance. Evidence for intrusion of a surface-water layer was not as clear in the second experiment as in the first. In addition to higher-frequency internal waves, as was observed in the first experiment, we also observed a low-frequency internal tidal wave of greater than 20 m amplitude that controlled the vertical distribution of the deep population of cells. We were unable to discern evidence of diel vertical migratory by the Alexandrium population in either of the two experiments.

  16. A severe red tide (Tampa Bay, 2005) causes an anomalous decrease in biological sound.

    PubMed

    Indeck, Katherine L; Simard, Peter; Gowans, Shannon; Lowerre-Barbieri, Susan; Mann, David A

    2015-09-01

    Although harmful algal blooms (HABs) are known to cause morbidity and mortality in marine organisms, their sublethal effects are poorly understood. The purpose of this study was to compare ambient noise levels during a severe HAB event in Tampa Bay, Florida, to those during non-HAB periods. Passive acoustic monitoring was conducted using bottom-mounted autonomous acoustic recorders during a severe HAB in summer 2005, and in summers 2006, 2011 and 2012 (non-severe HAB years). Ambient noise levels were significantly higher during the non-HAB years due to an abundance of snapping shrimp (Alpheidae) sounds and fish chorusing. The difference of sound intensity between the study years is most likely attributable to effects of the HAB on the abundance and/or behaviour of fish and snapping shrimp as a result of mortality and stress-induced behavioural modifications.

  17. Dispersion in the Yucatan coastal zone: Implications for red tide events

    NASA Astrophysics Data System (ADS)

    Enriquez, Cecilia; Mariño-Tapia, Ismael J.; Herrera-Silveira, Jorge A.

    2010-02-01

    The mechanisms governing dispersion processes in the northern Yucatan coast are investigated using a barotropic numerical model of coastal circulation, which includes wind-generated and large scale currents (i.e. Yucatan Current). This work provides the foundations for studying the dispersion of harmful algal blooms (HABs) in the area. Modelling experiments include effects of climatic wind (from long term monthly mean NCEP reanalysis), short term wind events (from in situ point measurements), and Yucatan Current (YC) characteristics. Its magnitude was approximated from published reports, and its trajectory from geostrophic current fields derived from altimeter data. These provided a range of real and climatic conditions to study the routes in which phytoplankton blooms may travel. The 2-D model results show that a synthetic and conservative bloom seeded in the Cabo Catoche (CC) region (where it usually grows), moves along the coast to the west up to San Felipe (SF), where it can either move offshore, or carry on travelling westwards. The transport to the west up to SF is greatly influenced by the trajectory, intensity and proximity of the YC jet to the peninsula, which enhances the westward circulation in the Yucatan Shelf. Numerical experiments show that patch dispersion is consistently to the west even under the influence of northerly winds. When the YC flows westward towards the Campeche Bank, momentum transfer caused by the YC jet dominates the dispersion processes over wind stress. On the other hand, when it flows closer to Cuba, the local processes (i.e. wind and bathymetry) become dominant. Coastal orientation and the Coriolis force may be responsible for driving the patch offshore at SF if external forcing decreases.

  18. MECHANISMS OF FLUID SHEAR-INDUCED INHIBITION OF POPULATION GROWTH IN A RED-TIDE DINOFLAGELLATE

    EPA Science Inventory

    Net population growth of some dinoflagellates is inhibited by fluid shear at shear stresses comparable with those generated during oceanic turbulence. Decreased net growth may occur through lowered cell division, increased mortality, or both. The dominant mechanism under various ...

  19. OPTICAL VARIABILITY ASSOCIATED WITH A GYMNODINIUM BREVE RED TIDE EVENT OFF NORTHWESTERN FLORIDA. (R827085)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  20. Chlorophyll-Protein Complexes from the Red-Tide Dinoflagellate, Gonyaulax polyedra Stein 1

    PubMed Central

    Boczar, Barbara A.; Prezelin, Barbara B.

    1987-01-01

    A comparision of high (330 microeinsteins per meter squared per second) and low (80 microeinsteins per meter squared per second) light grown Gonyaulax polyedra indicated a change in the distribution of chlorophyll a, chlorophyll c2, and peridinin among detergent-soluble chlorophyll-protein complexes. Thylakoid fractions were prepared by sonication and centrifugation. Chlorophyll-protein complexes were solubilized from the membranes with sodium dodecyl sulfate and resolved by Deriphat electrophoresis. Low light cells yielded five distinct chlorophyll-protein complexes (I to V), while only four (I′ to IV′) were evident in preparations of high light cells. Both high molecular weight complexes I and I′ were dominated by chlorophyll a absorption and associated with minor amounts of chlorophyll c. Both complexes II and II′ were chlorophyll a-chlorophyll c2-protein complexes devoid of peridinin and unique to dinoflagellates. The chlorophyll a:c2 molar ratio of both complexes was 1:3, indicating significant chlorophyll c enrichment over thylakoid membrane chlorophyll a:c ratios of 1.8 to 2:1. Low light complex III differed from all other high or low light complexes in that it possessed peridinin and had a chlorophyll a:c2 ratio of 1:1. Low light complexes IV and V and high light complexes III′ and IV′ were spectrally similar, had high chlorophyll a:c2 ratios (4:1), and were associated with peridinin. The effects of growth irradiance on the composition of chlorophyll-protein complexes in Gonyaulax polyedra differed from those described for other chlorophyll c-containing plant species. PMID:16665343