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Sample records for aerosolized red tide

  1. 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

  2. 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

  3. Inland Transport of Aerosolized Florida Red Tide Toxins

    PubMed Central

    Kirkpatrick, Barbara; Pierce, Richard; Cheng, Yung Sung; Henry, Michael S.; Blum, Patricia; Osborn, Shannon; Nierenberg, Kate; Pederson, Bradley A.; Fleming, Lora E.; Reich, Andrew; Naar, Jerome; Kirkpatrick, Gary; Backer, Lorraine C; Baden, Daniel

    2009-01-01

    Florida red tides, an annual event off the west coast of Florida, are caused by the toxic dinoflagellate, Karenia brevis. K. brevis produces a suite of potent neurotoxins, brevetoxins, which kill fish, sea birds, and marine mammals, as well as sickening humans who consume contaminated shellfish. These toxins become part of the marine aerosol, and can also be inhaled by humans and other animals. Recent studies have demonstrated a significant increase in symptoms and decrease lung function in asthmatics after only one hour of beach exposure during an onshore Florida red tide bloom. This study constructed a transect line placing high volume air samplers to measure brevetoxins at sites beginning at the beach, moving approximately 6.4 km inland. One non-exposure and 2 exposure studies, each of 5 days duration, were conducted. No toxins were measured in the air during the non-exposure period. During the 2 exposure periods, the amount of brevetoxins varied considerably by site and by date. Nevertheless, brevetoxins were measured at least 4.2 kilometers from the beach and/or 1.6 km from the coastal shoreline. Therefore, populations sensitive to brevetoxins (such as asthmatics) need to know that leaving the beach may not discontinue their environmental exposure to brevetoxin aerosols. PMID:20161504

  4. Inland Transport of Aerosolized Florida Red Tide Toxins.

    PubMed

    Kirkpatrick, Barbara; Pierce, Richard; Cheng, Yung Sung; Henry, Michael S; Blum, Patricia; Osborn, Shannon; Nierenberg, Kate; Pederson, Bradley A; Fleming, Lora E; Reich, Andrew; Naar, Jerome; Kirkpatrick, Gary; Backer, Lorraine C; Baden, Daniel

    2010-02-01

    Florida red tides, an annual event off the west coast of Florida, are caused by the toxic dinoflagellate, Karenia brevis. K. brevis produces a suite of potent neurotoxins, brevetoxins, which kill fish, sea birds, and marine mammals, as well as sickening humans who consume contaminated shellfish. These toxins become part of the marine aerosol, and can also be inhaled by humans and other animals. Recent studies have demonstrated a significant increase in symptoms and decrease lung function in asthmatics after only one hour of beach exposure during an onshore Florida red tide bloom.This study constructed a transect line placing high volume air samplers to measure brevetoxins at sites beginning at the beach, moving approximately 6.4 km inland. One non-exposure and 2 exposure studies, each of 5 days duration, were conducted. No toxins were measured in the air during the non-exposure period. During the 2 exposure periods, the amount of brevetoxins varied considerably by site and by date. Nevertheless, brevetoxins were measured at least 4.2 kilometers from the beach and/or 1.6 km from the coastal shoreline. Therefore, populations sensitive to brevetoxins (such as asthmatics) need to know that leaving the beach may not discontinue their environmental exposure to brevetoxin aerosols. PMID:20161504

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

    PubMed Central

    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.

    2010-01-01

    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

  6. 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

  7. 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

  8. 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.

  9. 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

  10. 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. PMID:21499552

  11. 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

  12. 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

  13. 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. PMID:20161425

  14. 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. PMID:19392675

  15. 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

  16. 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

  17. 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. PMID:22712002

  18. 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

  19. 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. PMID:20824108

  20. 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.

  1. 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.

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

    PubMed Central

    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.

    2010-01-01

    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

  3. 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. PMID:24563634

  4. 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.

  5. 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

  6. 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. PMID:21532966

  7. Application of database technology to red tide remote sensing

    NASA Astrophysics Data System (ADS)

    Leng, Xiuhua; Zhang, Jie; Ma, Yi; Zhang, Hongliang

    2003-05-01

    The red tide spectrum database is the basis and prerequisite for red tide hyperspectral remote sensing, a technical support for the field investigation on red tide and the main technical measure for red tide data management and application. The data in the database mentioned in this paper come mainly from the red tide mesocosm experiment, and include the simultaneously collected biological, chemical, hydrographic and meteorological data besides the spectrum data of red tide dominant species. The database has not only the conventional functions for data query, retrieval and plotting, but also the algorithmic functions for the ground object spectrum data processing in the Visual FoxPro system environment and the biological information extraction using the ground object spectrum data. This system is not only an effective application system for detecting the red tide organism, identifying the red tide dominant species and analyzing the characteristic amount of red tide organism, but also a powerful tool for the marine environmental protection and the red tide disaster reduction in the future.

  8. 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

  9. 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

  10. 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.

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

    PubMed

    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

    2004-04-01

    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

  12. 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

  13. Concentration and particle size of airborne toxic algae (brevetoxin) derived from ocean red tide events.

    PubMed

    Cheng, Yung Sung; McDonald, Jacob D; Kracko, Dean; Irvin, C Mitch; Zhou, Yue; Pierce, Richard H; Henry, Michael S; Bourdelaisa, Andrea; Naar, Jerome; Baden, Daniel G

    2005-05-15

    Red tides in the Gulf of Mexico are formed by blooms of the dinoflagellate Karenia brevis, which produces brevetoxins (PbTx). Brevetoxins can be transferred from water to air in the wind-powered whitecapped waves during red tide episodes. Inhalation exposure to marine aerosol containing PbTx causes respiratory problems. A liquid chromatograph/ tandem mass spectrometric method was developed for the detection and quantitation of several PbTxs in ambient samples collected during red tide events. This method was complemented by a previously developed antibody assay that analyzes the entire class of PbTx compounds. The method showed good linearity, accuracy, and reproducibility, allowing quantitation of PbTx compounds in the 10 pg/m3 range. Air concentrations of PbTxs and brevenal for individual samples ranged from 0.01 to 80 ng/m3. The particle size showed a single mode with a mass median diameter between 6 and 10 microm, which was consistent for all of the PbTx species that were measured. Our results imply that individual PbTxs were from the same marine aerosol or from marine aerosol that was produced from the same process. The particle size indicated the likelihood of high deposition efficiency in the respiratory tract with the majority of aerosol deposited in the upper airways and small but not insignificant deposition in the lower airways. PMID:15954221

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

    PubMed

    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

    2011-09-01

    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

  15. Illness associated with red tide--Nassau County, Florida, 2007.

    PubMed

    2008-07-01

    A "red tide" is a harmful algal bloom that occurs when toxic, microscopic algae in seawater proliferate to a higher-than-normal concentration (i.e., bloom), often discoloring the water red, brown, green, or yellow. Red tides can kill fish, birds, and marine mammals and cause illness in humans. Florida red tide is caused by the dinoflagellate Karenia brevis, which produces toxins called brevetoxins and is most commonly found in the Gulf of Mexico; however, K. brevis blooms also can occur along the Atlantic coast. On September 25, 2007, a cluster of respiratory illnesses was reported to the Nassau County Health Department (NCHD) in northeastern Florida. All of the ill persons were employed at a beach restoration worksite by a dredging company operating at Fernandina Beach; they reported symptoms of eye or respiratory irritation (e.g., coughing, sneezing, sniffling, and throat irritation). NCHD and the Florida Department of Health promptly conducted epidemiologic and environmental investigations and determined the illnesses likely were associated with exposure to a red tide along the Atlantic coast. These actions highlight the importance of rapid investigation of health concerns with potential environmental causes to enable timely notification of the public and prevent further illness. PMID:18600196

  16. 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.

  17. 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.

  18. [Red tides in México: a review].

    PubMed

    Cortés-Altamirano, R; Hernández-Becerril, D U; Luna-Soria, R

    1995-01-01

    With the purpose to make a review on the red tides occurence at mexican coasts, previous studies were analyzed. Dinoflagellates seem to be the main cause of toxic events mainly Gonyaulax polygramma, Gymnodinium catenatum, Pyrodinium bahamense var. compressum and Ptychodiscus brevis. There are other species which cause red tides but are not toxic. They are: Mesodinium rubrum, Gonyaulax triacantha, Noctiluca scintillans, Prorocentrum dentatum, Gymnodinium splendens, G. sanguineum, Ceratium tripos var. ponticum, C. furca, Scrippsiella trocoidea and Oscillatoria erythraea. The first of these is the most common cilliate of the Pacific coastlines and the last one is the most common cyanophyceae during the strong events of "El Niño". The magnitude is quite variable, from small stains of a hundred square meters to several square kilometers and its density ranges from 0.5 to 36 million cells/l. Their residence time goes from 1 or 2 days to as long as 5 months. The great densities are due to Prorocentrum dentatum and P. minimum, the latter is only observed in estuarine ponds for shrimp cultivation, they have not been related to poisoning episodes. New areas of the red tide occurrence have been recorded during the last decades, such as Acapulco Bay, Huatulco, Salinacruz and Puerto Madero. These localities and also Mazatlán, are the only regions in which paralytic shellfish poisoning (PSP) have registered fatal cases and in the Gulf of Mexico a great mortality of fishes has been noted due to ictiotoxin produced by Ptychodiscus brevis. On the other hand, at Yucatan and west coast of the Peninsula of California red tide events are little known. PMID:8900570

  19. 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

  20. 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.

  1. 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.

  2. 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. PMID:21218152

  3. [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. PMID:23002593

  4. 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.

  5. 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

  6. [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. PMID:22165212

  7. 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…

  8. 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.

  9. Research on red tide occurrences using enclosed experimental ecosystem in West Xiamen Harbor, China —Relationship between nutrients and red tide occurrence

    NASA Astrophysics Data System (ADS)

    Lin, Yu; Lin, Rong-Cheng

    2000-09-01

    This study on the distribution of phosphate and its relation to phytoplankton biomass in Western Xiamen Harbor using marine ecosystem enclosures to isolate the culture water from the tidal currents and salinity changes outside indicated that the phytoplankton biomass variation closely related to dissolved inorganic phosphorus (DIP) in the seawater as described by the equation: [Chl-a]=A×e-B[PO4]. The biomass changes lagged by about two days the corresponding DIP. The research also dealt with the minimal DIP concentration for stopping diatom bloom and the possible maximal diatom biomass was estimated from the DIP external concentration in the seawater. The threshold of DIP initiating Skeletonema costatum red tide was calculated for use as an index to forecast its red tides. In addition, the relationships between a dinoflagellate red tide and nutrients are discussed. The results showed that the multiplication of dinoflagellate was not entirely dependent on the nutrients in the seawater.

  10. Cochlodinium polykrikoides red tide detection in the South Sea of Korea using spectral classification of MODIS data

    NASA Astrophysics Data System (ADS)

    Son, Young Baek; Ishizaka, Joji; Jeong, Jong-Chul; Kim, Hyun-Choel; Lee, Taehee

    2011-12-01

    To distinguish true red tide water (particularly Cochlodinium polykrikoides blooms) from non-red tide water (false satellite high chlorophyll water) in the South Sea of Korea, we developed a systematic classification method using spectral information from MODIS level products and applied it to five different harmful algal bloom events. Red tide and nonred tide waters were classified based on four different criteria. The first step revealed that the radiance peaks of potential red tide water occurred at 555 and 678 nm. The second step separated optically different waters that were influenced by relatively low and high contributions of colored dissolved organic matter (CDOM) (including detritus) to chlorophyll. The third and fourth steps discriminated red tide water from non-red tide water based on the blue-to-green ratio in areas with lower and higher contributions of CDOM to chlorophyll, respectively. After applying the red tide classification (using the four criteria), the spectral response of the red tide water, which is influenced by pigment concentration, showed different slopes for the blue and green bands (lower slope at blue bands and higher slope at green bands). The opposite result was found for non-red tide water, due to decreasing phytoplankton absorption and increasing detritus/CDOM absorption at blue bands. The results were well matched with the discoloration of water (blue to dark red/brown) and delineated the areal coverage of C. polykrikoides blooms, revealing the nature of spatial and temporal variations in red tides. This simple spectral classification method led to increase user accuracy for C. polykrikoides and non-red tide blooms (>46% and >97%) and provided a more reliable and robust identification of red tides over a wide range of oceanic environments than was possible using chlorophyll a concentration, chlorophyll anomaly, fluorescence analysis, or proposed red tide detection algorithms.

  11. Study on the detection of red-tide outbreaks using big satellite database

    NASA Astrophysics Data System (ADS)

    Son, Young Baek; Eun, Yoon Joo; Park, Kyongseok; Lee, Sanghwan; Lee, Ryong; Kim, Sang-Hyun; Yoo, Sinjae

    2014-11-01

    Satellite remote sensing has been successfully employed to monitor and detect the increasing incidence of harmful algal blooms (HABs) under various water conditions. In this study, to establish a comprehensive monitoring system of HAB outbreaks (particularly Cochlodinium polykrikoides blooms) in the southern coast of Korea (SCK), we tested the several proposed red-tide detection methods using SeaWiFS and MODIS ocean color data. Temporal and spatial information of red tide events from 2002 to 2013 were obtained from the National Fisheries Research and Development of Korea (NFRDI), which were matched with synchronously obtained satellite-derived ocean color data. The spectral characteristics of C. polykrikoides red tides were that increased phytoplankton absorption at 443 nm and pigment backscattering 555 nm resulted in a steeper slope between 488 and 555 nm with a hinge point at 488 (or 490) nm. On the other hand, non-red tide water, typically were presented by broader radiance spectra between the blue and green bands were associated with reduced pigment absorption and backscattering. The analysis of ocean color imageries that captured C. polykrikoides red tide blooms showed discolored waters with enhanced pigment concentrations, high chlorophyll, fluorescence, absorption at 443 nm. However, most red tide detection algorithms found a large number of false positive but only a small number of true positive areas. These proposed algorithms are not useful to distinguish true red tide water from complex non-red tide water. Our proposed method substantially reduces the false signal rate (false positive) from strong absorption at short wavelengths and provide a more reliable and robust detection of C. polykrikoides blooms in the SCK from the space.

  12. 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. PMID:20383268

  13. 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. PMID:26337227

  14. 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. PMID:19234604

  15. 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

  16. 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. PMID:24461701

  17. [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. PMID:17891964

  18. Red tide optical index: in situ optics and remote sensing models

    NASA Astrophysics Data System (ADS)

    Cetinic, I.; Karp-Boss, L.; Boss, E.; Ragan, M. A.; Jones, B. H.

    2007-05-01

    Harmful Algal Blooms (HABs) are recurring events in the coastal ocean, and local economies that depend on beach and coastal use are often adversely affected by these events. Inherent optical properties (absorption and backscattering) of the HAB dinoflagellate Lingulodinium polyedrum were measured in order to develop specific index that would enable easier detection of this HAB organism in the field. It has been noticed that red to blue and red to green ratio of absorption in this species is much lower then other measured species. A red tide ratio was tested in the field during a red tide episode in the San Pedro Channel, using a Wetlabs acS flow-through system. The red tide index gave a distinguishable signal in areas where L.polyedrum was present. Remote sensing reflectance was calculated from field and laboratory IOP measurements, using reverse Quasi-Analythical Alghoritm and Hydrolight to evaluate if the red tide index can be detected in the remote sensing ocean color measurements.

  19. 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...

  20. 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...

  1. TOXICITY OF CLAY FLOCCULATION OF RED TIDE ORGANISMS ON BENTHIC ORGANISMS ERF 2001

    EPA Science Inventory

    Toxicity of Clay Flocculation of Red Tide Organisms on Benthic Organisms (Abstract). To be presented at the16th Biennial Conference of the Estuarine Research Foundation, ERF 2001: An Estuarine Odyssey, 4-8 November 2001, St. Pete Beach, FL. 1 p. (ERL,GB R854).

    We have eva...

  2. 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...

  3. 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.

  4. EFFECTS OF RED TIDE (KARENIA BREVIS) ON PISCIVOROUS BIRDS IN SARASOTA BAY, FLORIDA

    EPA Science Inventory

    Red tide will cause changes in the abundance and distribution of fishes, which will be accompanied by changes in the patterns of habitat use by birds. Birds will be affected by exposure to brevetoxin via their prey and they will also face decreased availability of prey during...

  5. 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. PMID:25003583

  6. 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. PMID:23628547

  7. 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.

  8. 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

  9. 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.

  10. 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

  11. 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

  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. PMID:18758951

  13. 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.

  14. 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. PMID:27107332

  15. 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

  16. 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

  17. 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.

  18. 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

  19. 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. PMID:26627232

  20. 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...

  1. A numerical analysis of landfall of the 1979 red tide of Karenia brevis along the west coast of Florida

    NASA Astrophysics Data System (ADS)

    Walsh, John J.; Haddad, Kenneth D.; Dieterle, Dwight A.; Weisberg, Robert H.; Li, Zhenjiang; Yang, Huijun; Muller-Karger, Frank E.; Heil, Cynthia A.; Bissett, W. Paul

    2002-01-01

    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 of these populations at the coast in our model matches shoreline data sets as well. The simulated vertical movement of K. brevis, in response to light-cued migration and nocturnal mixing, also mimics these aspects of the next fall red tide in 1980, suggesting that sunrise populations may provide the strongest surface signal, for detection of red tides by remote sensors aboard aircraft and satellites. Once a mature red tide is formed, a light-regulated maximal growth rate of 0.15 day -1, reflecting nutrient-limitation, and no other loss processes may be an adequate description of population dynamics above the 30-40 m isobaths, where blooms of K. brevis originate. Within shallow waters at the 10-m isobath, however, an apparent larger growth rate of 0.80 day -1—as a presumed consequence of frontal aggregations—must be offset by unknown processes of algal mortality. Likely candidates for cumulative, biomass-dependent losses are UV-B irradiation, microbial-induced lysis, and unselective grazing pressure from copepods, protozoans and heterotrophic dinoflagellates.

  2. Efficacy of aerosols for managing the red flour beetle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pest management professionals commonly utilize aerosolized liquid applications, also known as fogging, for management of stored-product insects, including the red flour beetle. These applications are part of a potential methyl bromide replacement technology because they could increase the time inte...

  3. 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.

  4. 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. PMID:26521549

  5. Toxic red tides and harmful algal blooms: A practical challenge in coastal oceanography

    NASA Astrophysics Data System (ADS)

    Anderson, Donald M.

    1995-07-01

    The debate over the relative value of practical or applied versus fundamental research has heated up considerably in recent years, and oceanography has not been spared this re-evaluation of science funding policy. Some federal agencies with marine interests have always focused their resources on practical problems, but those with a traditional commitment to basic research such as the National Science Foundation have increasingly had to fight to maintain their freedom to fund quality science without regard to practical or commercial applications. Within this context, it is instructive to highlight the extent to which certain scientific programs can satisfy both sides of this policy dilemma—i.e. address important societal issues through advances in fundamental or basic research. One clear oceanographic example of such a program involves the phenomena called "red tides" or "harmful algal blooms". This paper describes the nature and extent of the problems caused by these outbreaks, emphasizing the alarming expansion in their incidence and their impacts in recent years, both in the U.S. and worldwide. The objective is to highlight fundamental physical, biological, and chemical oceanographic question that must be addressed if we are to achieve the practical goal of scientifically based management of fisheries resources, public health, and ecosystem health in regions threatened by toxic and harmful algae.

  6. 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. PMID:24727069

  7. 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.

  8. 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.

  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. Transcriptomic response of the red tide dinoflagellate, Karenia brevis, to nitrogen and phosphorus depletion and addition

    PubMed Central

    2011-01-01

    Background The role of coastal nutrient sources in the persistence of Karenia brevis red tides in coastal waters of Florida is a contentious issue that warrants investigation into the regulation of nutrient responses in this dinoflagellate. In other phytoplankton studied, nutrient status is reflected by the expression levels of N- and P-responsive gene transcripts. In dinoflagellates, however, many processes are regulated post-transcriptionally. All nuclear encoded gene transcripts studied to date possess a 5' trans-spliced leader (SL) sequence suggestive, based on the trypanosome model, of post-transcriptional regulation. The current study therefore sought to determine if the transcriptome of K. brevis is responsive to nitrogen and phosphorus and is informative of nutrient status. Results Microarray analysis of N-depleted K. brevis cultures revealed an increase in the expression of transcripts involved in N-assimilation (nitrate and ammonium transporters, glutamine synthetases) relative to nutrient replete cells. In contrast, a transcriptional signal of P-starvation was not apparent despite evidence of P-starvation based on their rapid growth response to P-addition. To study transcriptome responses to nutrient addition, the limiting nutrient was added to depleted cells and changes in global gene expression were assessed over the first 48 hours following nutrient addition. Both N- and P-addition resulted in significant changes in approximately 4% of genes on the microarray, using a significance cutoff of 1.7-fold and p ≤ 10-4. By far, the earliest responding genes were dominated in both nutrient treatments by pentatricopeptide repeat (PPR) proteins, which increased in expression up to 3-fold by 1 h following nutrient addition. PPR proteins are nuclear encoded proteins involved in chloroplast and mitochondria RNA processing. Correspondingly, other functions enriched in response to both nutrients were photosystem and ribosomal genes. Conclusions Microarray analysis

  11. Altererythrobacter xiamenensis sp. nov., an algicidal bacterium isolated from red tide seawater.

    PubMed

    Lei, Xueqian; Li, Yi; Chen, Zhangran; Zheng, Wei; Lai, Qiliang; Zhang, Huajun; Guan, Chengwei; Cai, Guanjing; Yang, Xujun; Tian, Yun; Zheng, Tianling

    2014-02-01

    A Gram-stain-negative, yellow-pigmented, aerobic bacterial strain, designated LY02(T), was isolated from red tide seawater in Xiamen, Fujian Province, China. Growth was observed at temperatures from 4 to 44 °C, at salinities from 0 to 9% and at pH from 6 to 10. Phylogenetic analysis based on 16S rRNA gene sequencing revealed that the isolate was a member of the genus Altererythrobacter, which belongs to the family Erythrobacteraceae. Strain LY02(T) was related most closely to Altererythrobacter marensis MSW-14(T) (97.2% 16S rRNA gene sequence similarity), followed by Altererythrobacter ishigakiensis JPCCMB0017(T) (97.1%), Altererythrobacter epoxidivorans JCS350(T) (97.1%) and Altererythrobacter luteolus SW-109(T) (97.0%). The dominant fatty acids were C(18 : 1)ω7c, C(17 : 1)ω6c and summed feature 3 (comprising C(16 : 1)ω7c and/or C(16 : 1)ω6c). DNA-DNA hybridization showed that strain LY02(T) possessed low DNA-DNA relatedness to A. marensis MSW-14(T), A. ishigakiensis JPCCMB0017(T), A. epoxidivorans JCS350(T) and A. luteolus SW-109(T) (mean ± SD of 33.2 ± 1.3, 32.1 ± 1.0, 26.7 ± 0.7 and 25.2 ± 1.1 %, respectively). The G+C content of the chromosomal DNA was 61.2 mol%. The predominant respiratory quinone was ubiquinone-10 (Q-10). According to its morphology, physiology, fatty acid composition and 16S rRNA gene sequence data, the novel strain most appropriately belongs to the genus Altererythrobacter, but can readily be distinguished from recognized species. The name Altererythrobacter xiamenensis sp. nov. is proposed (type strain LY02(T) = CGMCC 1.12494(T) = KCTC 32398(T) = NBRC 109638(T)). PMID:24158949

  12. 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. PMID:25356530

  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. Analysis of Large Red Tide Bloom off the South East/Japan Sea Using Multi-Satellite Measurements in the Summer of 2013.

    NASA Astrophysics Data System (ADS)

    Kim, D. W.; Jo, Y. H.

    2014-12-01

    A large red tide bloom in the south East/Japan Sea had occurred during the summer of 2013. The bloom had lasted for 51 days from 17th of July to 5th of September. During this time period, the red tide dinoflagellate, Cochlodinium polykrikoides was found. C.polykrikoides has been known for preventing oxygen exchanges of fish gills by attaching, leading to perish fishes. Thus, it is important to understand various stages of conditions of red tide developing progress, especially C.polykrikoides, because the fishery industry was damaged due to sporadic and fatal red tide. According to previous research, optimum growth parameters for C.polykrikoides are relatively high temperature and salinity (30-32°C, 30-33psu). We examined causes of red tide bloom using multi-satellite measurements. Research results show that this red tide bloom is related to three processes: enough sunlight, upwelling favorable winds, and warm water. Based on Geostationary Ocean Color Imager (GOCI), cloud presence during August 2013 was smallest during last three years. So the first condition to form such a large bloom is insolation. At the same time, the wind was favorable for the Ekman pumping off the coast of the south East Japan Sea estimated using wind data measured by the Advanced Microwave Scanning Radiometer-EOS (AMSR-E). In addition to offshore Ekman pumping, the onshore upwelling was also observed, which shows relatively cold water on the coastal regions, measured by the Moderate Resolution Imaging Spectroradiometer (MODIS) of Sea Surface Temperature (SST). Accordingly, coastal upwelling supplies nutrients for flourishing C.polykrikoides which is the second condition. The third condition is relatively warm sea surface water of August of 2013 in the region compared to previous years. Furthermore, the Sea Surface Height Anomaly (SSHA) data was also used to understand the current systems around the red tide bloom. In the summer of 2013 at the East/Japan Sea, abundance of insolation, offshore

  15. 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.

  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. 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. PMID:24502723

  18. 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.

  19. 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

  20. 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

  1. 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

  2. Comparison of Techniques for Satellite Detection of Red Tides in the Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Amin, R.; Zhou, J.; Gilerson, A.; Gross, B.; Moshary, F.; Ahmed, S.

    2008-12-01

    Toxic dinoflagellate Karenia brevis (K. brevis) blooms have regularly been reported in the Gulf of Mexico, particularly in the West Florida Shelf (WSF), and increasing efforts have gone into their detection, which, from space, still remains a challenge in the coastal waters due to the interferences from land and bottom reflectance. Detection algorithms that use blue-green reflectance ratios often have more uncertainties than the red or red-NIR algorithms, due to spectral interferences from colored dissolved organic matters (CDOM), which furthermore, does not correlate with chlorophyll in the coastal waters. Recently we proposed a bloom detection algorithm which uses the difference between two selected bands in the red (identified by us as the Red Band Difference (RBD)) technique, and a K. brevis classification technique, which uses the normalized difference of the two selected red bands (and identified by us as the K. brevis bloom index (KBBI)). In this study, we apply both of these approaches to satellite measurements by the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Medium Resolution Imaging Spectrometer (MERIS) ocean color sensors, which have a couple of bands in the red and NIR regions. We also make a comparison between our approaches and Fluorescence Line Height (FLH) approaches applied to bloom detection. Our analysis shows that although FLH can sometimes be used to detect blooms, it breaks down in highly scattering waters, often erroneously identifying other bloom like features, such as sediment plumes, as algal blooms, while our approaches generally correctly distinguish bloomed areas (give positive values) from non-bloom areas (give negative values) even in the highly scattering waters. Further analysis of the impact of CDOM on RBD and KBBI also shows that these techniques are less sensitive to CDOM. Thus, while there is a small reduction in the chlorophyll fluorescence signal due to the absorption of CDOM in the excitation wavebands

  3. Effects of Fe and Mn on the growth of a red tide dinoflagellate Scrippsiella trochoidea (Stein) Loeblch III

    NASA Astrophysics Data System (ADS)

    Qin, Xiao-Ming; Zhou, Jing-Zhong; Qian, Pei-Yuan

    1997-06-01

    Batch culture experiments were conducted with a red tide dinoflagellate Scrippsiella trochoidea (Stein) Loeblch III collected from Jiaozhou Bay, Shangdong, China. Growth rates and oellular Chl—a were measured in media with iron and manganese ion concentrations controlled at different levels using EdTA-trace metal buffer systems. Cell density increased 3.2 times to 6.5 times over the range of lowest (0 mol/L) to highest (10-5 mol/L) iron and manganese ion concentrations. The range of cell density response was much lower than the range of total available iron and manganese, which was >100—fold that of Fe. This nonlinear relationship indicates that the cells adapt to make more efficient use of iron and manganese under limiting conditions. The cellular Chl—a content maximized after 3 days incubation and then decreased gradually under either iron or manganese limitation conditions. It indicated that the algae gained higher photosynthesis ability when transferred to a new environment. Growth responses to iron and manganese limitation can be both modeled according to the equation of Monod. The half—saturation constant for growth, k, is 4.6×10-8 mol/L for Fe and 5.1×10-8 mol/L for Mn. Our results showed that the iron availability in Jiaozhou Bay does not limit the growth of S. trochoidea.

  4. [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. PMID:24288981

  5. 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

  6. 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.

  7. 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

  8. 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. PMID:25170191

  9. 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

  10. 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. PMID:27318300

  11. 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.

  12. 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. PMID:25678466

  13. 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

    2016-01-01

    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.

  14. [Growth inhibition of the four species of red tide microalgae by extracts from Enteromorpha prolifera extracted with the five solvents].

    PubMed

    Sun, Ying-Ying; Liu, Xiao-Xiao; Wang, Chang-Hai

    2010-06-01

    To study the effects of extracts of Enteromorpha prolifera on the growth of the four species of red tide microalgae (Amphidinium hoefleri, Karenia mikimitoi, Alexandrium tamarense and Skeletonema costatum), the extracts were extracted with five solvents (methanol, acetone, ethyl acetate, chloroform and petroleum ether), respectively. Based on the observation of algal morphology and the measurement of algal density, cell size and the contents of physiological indicators (chlorophyll, protein and polysaccharide), the results showed methanol extracts of E. prolifera had the strongest action. The inhibitory effects of A. hoefleri, K. mikimitoi, A. tamarense and S. costatum by the methanol extracts were 54.0%, 48.1%, 44.0% and 37.5% in day 10, respectively. The extracts of E. prolifera extracted with methanol, acetone and ethyl acetate caused cavities, pieces and pigment reduction in cells, and those with chloroform and petroleum ether caused goffers on cells. The extracts of E. prolifera extracted with all the five solvents decreased athletic ability of the cells, among which those extracted with ethyl acetate, chloroform and petroleum ether decreased cell size of test microalgae. The further investigation found that the methanol extracts significantly decreased contents of chlorophyll, protein and polysaccharide in the cells of those microalgae. The inhibitory effect of chlorophyll, protein and polysaccharide contents of four species of microalgae by the methanol extracts was about 51%. On the basis of the above experiments, dry powder of E. prolifera were extracts with methanol, and extracts were obtained. The methanol extracts were partitioned to petroleum ether phase, ethyl acetate phase, n-butanol phase and distilled water phase by liquid-liquid fractionation, and those with petroleum ether and ethyl acetate significantly inhibited the growth of all test microalgae, and the inhibitory effect of four species of microalgae by those two extracts was above 25% in day

  15. 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

  16. 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. PMID:26370816

  17. 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

  18. 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.

  19. ECOHAB - HYDROGRAPHY AND BIOLOGY TO PROVIDE INFORMATION FOR THE CONSTRUCTION OF A MODEL TO PREDICT THE INITIATION, MAINTANENCE AND DISPERSAL OF RED TIDE ON THE WEST COAST OF FLORIDA

    EPA Science Inventory

    This program is part of a larger program called ECOHAB: Florida that includes this study as well as physical oceanography, circulation patterns, and shelf scale modeling for predicting the occurrence and transport of Karenia brevis (=Gymnodinium breve) red tides. The physical par...

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Differential responses of stress proteins, antioxidant enzymes, and photosynthetic efficiency to physiological stresses in the Florida red tide dinoflagellate, Karenia brevis.

    PubMed

    Miller-Morey, Jeanine S; Van Dolah, Frances M

    2004-08-01

    This study identifies stress proteins and antioxidant enzymes that may play a role in the survival strategies of the Florida red tide dinoflagellate, Karenia brevis. Heat shock protein 60 (Hsp 60), mitochondrial small heat shock protein (mitosHsp), chloroplastic small heat shock protein (chlsHsp), Mn superoxide dismutase (SOD), and Fe SOD were first identified by Western blotting. The induction of these proteins in laboratory cultures in response to elevated temperatures, hydrogen peroxide, lead, or elevated light intensities was next assessed. In parallel, F(V)/F(M), a measurement of photosynthetic efficiency and common proxy of cellular stress, was determined. Hsp 60, Fe SOD, and Mn SOD were induced following exposure to elevated temperatures, hydrogen peroxide, or lead. MitosHsp responded only to heat, whereas chlsHsp responded only to H(2)O(2)-induced stress. The expression of stress proteins and antioxidant enzymes appears to be a more sensitive indicator of heat or chemically induced stresses than F(V)/F(M). However, F(V)/F(M) decreased significantly in response to elevated light intensities that did not induce the expression of stress proteins. These results identify for the first time stress proteins and antioxidant enzymes in K. brevis, provide evidence for differential sensitivity of cellular organelles to various sources of stress, and confirm the presence of conserved stress responses observed across phyla in a dinoflagellate. PMID:15536057

  5. Five red tide species in genus Prorocentrum including the description of Prorocentrum donghaiense Lu SP. nov. from the East China Sea

    NASA Astrophysics Data System (ADS)

    Lu, Dou-Ding; Goebel, Jeanette

    2001-12-01

    A new planktonic dinoflagellate, Prorocentrum donghaiense Lu sp. nov., is described in the present paper. The water sample was collected from the Changjiang Estuary, the East China Sea. The species identification is based on shape, size, surface micro-morphology, ornamentation of thecal plates and the architecture of the periflagellar area and the intercalary bands as seen by light and scanning electron microscope. Prorocentrum donghaiense Lu sp. nov. is compared with other prorocentrum species with respect to morphological characteristics and bloom behavior. It is not known whether Prorocentrum donghaiense Lu sp. nov produces phycotoxins like some other Prorocentrum species. Four other red tide species in the family Prorocentraceae (Dinophyceae), namely P. balticum, P. minimum, P. micans, P. triestinum, were examined and identified by light and scanning electron microscope. They have been recorded as bloom-forming species. Some aggregates of Prorocentrum are observed at the end of blooms. An event of strong discoloration caused by P. donghaiense could be detected by satellite sensor in the East China Sea in the late spring of 1995.

  6. 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

  7. 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 day to day…

  8. 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

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

    PubMed

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

    2010-06-01

    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 ≥1.5×10(4) 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

  10. Optimization of blood collection card method/enzyme-linked immunoassay for monitoring exposure of bottlenose dolphin to brevetoxin-producing red tides.

    PubMed

    Maucher, Jennifer M; Briggs, Lyn; Podmore, Colleen; Ramsdell, John S

    2007-01-15

    Blood collection cards have been successfully used as a tool to monitor brevetoxin (PbTx) exposure in several species, including fish, mice, and rats. Previous methanolic methods used for extracting brevetoxin from blood collection cards have shown dolphin blood to have matrix difficulties in several biological assays. To better biomonitor protected marine mammal species in the Florida area, which is historically prone to unusual mortality events caused by brevetoxin exposure, we have modified the previous extraction method to consistently recover brevetoxin with a known efficiency from dolphin blood collection card samples with minimal matrix interference. A combination of phosphate-buffered saline (PBS) with 6% MeOH and 100% acetonitrile was used to elute blood from the cellulose card and precipitate proteins, respectively. Analysis was performed using a newly developed direct enzyme-linked immunoassay (ELISA), which yields a sample limit of quantification of 1 ng PbTx-3 equiv/mL. This extraction method allowed for linear recovery of PbTx-3 spiked into dolphin blood (1-30 ng/mL) with a consistent recovery rate of 58% and has subsequently been used to monitor brevetoxins in dolphins, as well as sea turtles and manatees, in regions endemic to red tides. In addition, two known metabolites of PbTx-2 were isolated and also found to be detectable using the ELISA. The cysteine conjugate (m/z 1018) and cysteine sulfoxide conjugate (m/z 1034) were found to have linear recoveries of 87% and 66%, respectively. In summary, this method of extracting brevetoxins and their metabolites from blood collection cards, in conjunction with the ELISA detection method, is a simple and reliable way to biomonitor physiologically relevant toxin levels in protected marine animals. PMID:17310722

  11. On the application of Open-Path Fourier Transform Infra-Red spectroscopy to measure aerosols: Observations of water droplets

    SciTech Connect

    Hashmonay, R.A.; Yost, M.G.

    1999-04-01

    This paper proposes the application of Open-Path Fourier Transform Infra-Red (OP-FTIR) spectroscopy to measure aerosols. A preliminary experiment conducted in a standard shower chamber generated a condensed water aerosol cloud. The OP-FTIR beam acquired spectra through the cloud of water droplets. The authors matched calculated extinction spectra to measured extinction in the spectral range between 500 and 5,000 wavenumbers by using Mie theory for spherical particles. The results indicate that size distribution parameters may be retrieved from OP-FTIR spectra acquired over a 1 km optical path with reasonable detection limits on the order of 10 {micro}g{center_dot}m{sup {minus}3} for aerosols with optical properties equivalent to water.

  12. 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.

  13. 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.

  14. 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…

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  16. 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.

  17. 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

  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. Students' Understanding of Tides.

    ERIC Educational Resources Information Center

    Viiri, Jouni

    2000-01-01

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

  3. 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.

  4. 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)

  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. Dynamic Elastic Tides

    NASA Astrophysics Data System (ADS)

    Wisdom, Jack; Meyer, Jennifer

    2016-04-01

    This is an exploration of dynamic tides on elastic bodies. The body is thought of as a dynamical system described by its modes of oscillation. The dynamics of these modes are governed by differential equations that depend on the rheology. The modes are damped by dissipation. Tidal friction occurs as exterior bodies excite the modes and the modes act back on the tide raising body. The whole process is governed by a closed set of differential equations. Standard results from tidal theory are recovered in a two-timescale approximation to the solution of these differential equations.

  7. 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.

  8. 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.

  9. Tides in Titan

    NASA Technical Reports Server (NTRS)

    Rappaport, Nicole J.

    1997-01-01

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

  10. 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

  11. 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.

  12. 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.

  13. Astronomical tides and earthquakes

    NASA Astrophysics Data System (ADS)

    Wu, Xiaoping; Mao, Wei; Huang, Yong

    2001-03-01

    A review on the studies of correlation between astronomical tides and earthquakes is given in three categories, including (1) earthquakes and the relative locations of the sun, the moon and the earth, (2) earthquakes and the periods and phases of tides and (3) earthquakes and the tidal stress. The first two categories mainly investigate whether or not there exist any dominant pattern of the relative locations of the sun, the moon and the earth during earthquakes, whether or not the occurrences of earthquakes are clustered in any special phase during a tidal period, whether or not there exists any tidal periodic phenomenon in seismic activities, By empasizing the tidal stress in seismic focus, the third category investigates the relationship between various seismic faults and the triggering effects of tidal stress, which reaches the crux of the issue. Possible reasons to various inconsistent investigation results by using various methods and samples are analyzed and further investigations are proposed.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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, ...

  15. 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.

  16. 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.

  17. Tide gate valve

    SciTech Connect

    Raftis, S. G.

    1985-01-08

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

  18. Tides of the British Seas

    ERIC Educational Resources Information Center

    Sandon, Frank

    1975-01-01

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

  19. 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

  20. 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

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

    PubMed

    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

  2. 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

  3. 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.

  4. 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.

  5. M2 World Ocean tide from tide gauge measurements

    NASA Astrophysics Data System (ADS)

    Francis, O.; Mazzega, P.

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

  6. 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.

  7. 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

  8. 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.

  9. Tides in Colliding Galaxies

    NASA Astrophysics Data System (ADS)

    Duc, Pierre-Alain; Renaud, Florent

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

  10. Seasonal and inter-annual variability of aerosol optical properties during 2005-2010 over Red Mountain Pass and Impact on the Snow Cover of the San Juan Mountains

    NASA Astrophysics Data System (ADS)

    Singh, R. P.; Gautam, R.; Painter, T. H.

    2011-12-01

    Growing body of evidence suggests the significant role of aerosol solar absorption in accelerated seasonal snowmelt in the cryosphere and elevated mountain regions via snow contamination and radiative warming processes. Characterization of aerosol optical properties over seasonal snow cover and snowpacks is therefore important towards the better understanding of aerosol radiative effects and associated impact on snow albedo. In this study, we present seasonal variations in column-integrated aerosol optical properties retrieved from AERONET sunphotometer measurements (2005-2010) at Red Mountain Pass (37.90° N, 107.72° W, 3368 msl) in the San Juan Mountains, in the vicinity of the North American Great Basin and Colorado Plateau deserts. The aerosol optical depth (AOD) measured at 500nm is generally low (< 0.2) in the climatological monthly means but exhibits strong seasonal variability with very low background values of about 0.05 during winter season, but is found to significantly increase more than 5-6 times during summer months with values up to 0.3-0.4. Together with the spectral variations in AOD, the Angstrom Wavelength Exponent (α) typically varies in the range of 1-2 indicating the dominance of fine-mode particulates. However, during summer months, nearly 30% of α values are observed below 0.5 thus suggesting an increased influx of coarse-mode aerosols compared to other seasons. The higher AOD and lower α is most likely a result of the summer-time enhanced convection and upslope pollutant transport. In addition, the possibility of the observed increased coarse-mode influence associated with mineral dust influx cannot be ruled out, due to westerly-airmass driven transport from arid/desert regions as suggested by backward trajectory simulations. A meteorological coupling is also found in the summer season between AOD and column water vapor retrieved from AERONET with co-occurring enhanced water vapor and AOD. Based on column measurements, it is difficult

  11. 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

  12. 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.

  13. Interpreting and analyzing King Tide in Tuvalu

    NASA Astrophysics Data System (ADS)

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

    2014-02-01

    The spatial and temporal distribution of sea-level rise has the potential to cause regional flooding in certain areas, and low-lying island countries are severely at risk. Tuvalu, an atoll country located in the southwest Pacific Ocean, has been inundated by this regional flooding for decades. Tuvaluans call this regional flooding phenomenon King Tide, a term not clearly defined, blaming it for loss of life and property in announcing their intention to migrate. In this study, we clarified and interpreted King Tide, and analyzed the factors of King Tide in Tuvalu. Using tide gauge and topographical data, we estimated that 3.2 m could be considered the threshold of King Tide, which implied half of the island of Tuvalu was flooded with seawater. This threshold is consistent with the finding of the National Oceanic and Atmospheric Administration that King Tide events occur once or twice a year. We surveyed 28 King Tide events to analyze the factors of regional flooding. Tide gauge and satellite altimeter data from 1993 to 2012 were cross-validated and indicated that the King Tide phenomenon is significantly related to the warm-water effect. Warm water contributed to the King Tide phenomenon by an average of 5.1% and a maximum of 7.8%. The height of King Tide is affected by the combined factors of spring tide, storm surge, climate variability, and, significantly, by the warm-water effect.

  14. 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.

  15. Barometric and Earth Tide Correction

    Energy Science and Technology Software Center (ESTSC)

    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.

  16. 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.

  17. 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.

  18. 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.

  19. Intercomparison of satellite-derived aerosol optical depths with ship-based microtops observations over the Red Sea from the AEGAEO campaign in 2011 and insights into dust influence over the region

    NASA Astrophysics Data System (ADS)

    Bantges, R.; Brindley, H.; Stenchikov, G. L.; De La Torre, P.; Bangalath, H.; Smirnov, A.

    2012-12-01

    Among its many influences on the climate system, dust aerosol can substantially modify the Earth's radiation balance via its direct impact on both the amount of reflected shortwave and emitted longwave energy escaping to space. Over ocean, instantaneous aircraft and satellite observations of dust events have shown that the reflected shortwave component can be enhanced by over 100Wm-2. However, while there have been a number of observational and modelling campaigns designed to probe dust-climate interactions over North Africa, the North Atlantic, Asia, the Americas and the Mediterranean, relatively little attention has been paid to the Arabian Peninsula and the Red Sea. Here we describe a novel set of ship-based observations aimed at characterising aerosol loading over the Red Sea via a series of five cruises through September-December 2011. Typically ship-based aerosol loadings were indicative of background, hazy conditions, with 0.6 micron optical depths of the order 0.2. However, somewhat elevated loadings were also captured during the earliest of the ship cruises in September, optical depths reaching ~ 0.5. In all cases, comparisons of these data with co-located satellite retrievals from the SEVIRI and MODIS sensors showed good overall agreement with correlation coefficients exceeding 0.9 for all five cruises, giving confidence in the general performance of the retrieval algorithms employed. To probe the general behaviour of the region in more detail, aerosol optical depths from each satellite sensor were then used to create a record of aerosol loading over the Red Sea for the full September-December 2011 time period. The fifteen minute time resolution data available from SEVIRI provides insight into the timing and duration of specific dust events, while the enhanced spatial resolution of MODIS can allow greater detail to be discerned at the instrument overpass times. Initial results show the expected pattern of behaviour, with enhanced aerosol optical depths in

  20. 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.

  1. Tide following wave power machine

    SciTech Connect

    Murphy, J.T.

    1982-09-21

    At least two spaced piers are constructed on a suitable tidal beach extending from the shore into the water a predetermined distance to meet the first breaking waves at low tide. A carriage is movably supported on the piers on an inclined path, the carriage having a frame supporting a pair of spaced sprocket wheels on each end over which is passed an endless belt. The ends of a plurality of blades are secured to the chain in spaced relation completely thereabout. Each sprocket wheels closest to shore is connected to a gear train for transmitting the torque generated by the wave action to a power belt extending along each pier to a transducer located at the shore end of the pier. Means are provided for moving the carriage on the pier on an inclined path in and out from the shore to meet the level of the changing tide so as to continuously generate power throughout the tidal wave.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Atmospheric tides in Gale Crater, Mars

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

    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 non-sun-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.

  10. 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.

  11. Dissipation and Synchronization due to Creeping Tides.

    NASA Astrophysics Data System (ADS)

    Ferraz-Mello, Sylvio

    2012-05-01

    We present a new reophysical theory of the dynamical tides of celestial bodies. It is founded on a Newtonian creep instead of the classical delayed elastic approach of the standard viscoelastic theories. All results of the theory derive from the solution of a non-homogeneous ordinary differential equation and lags appear as a natural outcome from the solution of the equation and are not external ad hoc quantities plugged in an elastic model. The lag due to the Newtonian creep is proportional to the tide frequency (as in Darwin’s original theory), and is necessarily small. The amplitudes depend on the viscosity of the body and on the frequency of the tide. As a consequence, the so-called pseudo-synchronous rotation has an excess velocity roughly proportional to 6ne2/(χ2+1/χ2) (χ is the tide frequency in units of a relaxation factor inversely proportional to the viscosity) instead of the exact 6ne2 of standard theories. The dissipation is inversely proportional to (χ + 1/χ) thus, in the inviscid limit it is roughly proportional to the frequency (as in standard theories), but that behavior is inverted when the viscosity is high and the response factor much smaller than the tide frequency. When the viscosity is high, however, the creeping tide fails to reproduce the actual geometric tide and, to reconcile theory and observation, we need to assume the coexistence of a small elastic tide superposed to the creeping tide. The theory is applied to several Solar System and extrasolar bodies and the values of the relaxation factor μ (and its current correspondent Q) are derived for these bodies on the basis of currently available data.

  12. Stratospheric sudden warming and lunar tide

    NASA Astrophysics Data System (ADS)

    Yamazaki, Yosuke; Kosch, Michael

    2016-07-01

    A stratospheric sudden warming is a large-scale disturbance in the middle atmosphere. Recent studies have shown that the effect of stratospheric sudden warnings extends well into the upper atmosphere. A stratospheric sudden warming is often accompanied by an amplification of lunar tides in the ionosphere/theremosphere. However, there are occasionally winters when a stratospheric sudden warming occurs without an enhancement of the lunar tide in the upper atmosphere, and other winters when large lunar tides are observed without a strong stratospheric sudden warming. We examine the winters when the correlation breaks down and discuss possible causes.

  13. 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)

  14. 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)

  15. Using Tide Data in Introductory Classes

    NASA Astrophysics Data System (ADS)

    de Jong, Marvin L.

    2006-11-01

    Ocean tides 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 tides1,2 but to make some suggestions about how, on their own, students can discover relationships between hypotheses and actual evidence.

  16. 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.

  17. Mapping Hurricane Rita inland storm tide

    USGS Publications Warehouse

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

    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.

  18. Mapping hurricane rita inland storm tide

    USGS Publications Warehouse

    Berenbrock, C.; Mason, R.R., Jr.; 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.

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. The Atmospheric Tides Middle Atmosphere Program (ATMAP)

    NASA Technical Reports Server (NTRS)

    Forbes, J. M.

    1989-01-01

    Atmospheric tides, oscillations in meteorological fields occurring at subharmonics of a solar or lunar day, comprise a major component of middle atmosphere global dynamics. The purpose of the 1982 to 1986 Atmospheric Tides Atmosphere Program (ATMAP) was to foster an interaction between experimentalists, data analysts, and theoreticians and modelers, in order to better understand the physical mechanisms governing tides and their relationships to other scales of motion, and to thereby explain features of observed tidal structures in the mesosphere and lower thermosphere. The ATMAP consisted of seven observational campaigns, five workshops and a climatological study. A historical perspective is provided along with a summary of major results, conclusions, and recommendations for future study which have emerged from the ATMAP.

  5. 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)

  6. 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.

  7. 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.

  8. 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)

  9. 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,…

  10. Fracture characterization using Earth tide analysis

    NASA Astrophysics Data System (ADS)

    Burbey, Thomas J.

    2010-01-01

    SummaryWells tapping confined aquifer systems are known to commonly produce water-level fluctuations caused by strain-induced Earth tides. In this investigation, a straightforward methodology is presented for quantifying the specific storage and secondary porosity of a fractured fault-zone aquifer system using Earth tides. Water-level and barometric pressure head data are smoothed and then filtered to remove low frequency responses. The resulting tidal signals are used in the program BAYTAP-G to yield amplitude and phase shifts of all the major tidal groups. The resulting tidal parameters can be used to compute the time-dependent volumetric strain caused by the M 2 and O 1 tides. Stress-strain hysteresis loops are produced when the reduced water levels are compared to the volumetric strain induced by these tides. For amplification factors near unity (representing the ratio of pressure response to tidal loading in the fracture to water-level response in the well) the slopes of the loops represent the specific storage of the fracture. The barometric efficiency and specific storage can then be used to estimate a secondary porosity and other parameters of the aquifer system. This analysis was carried out at the Fractured Rock research Site (FRS) in the Blue Ridge Physiographic Province in Floyd County, Virginia.

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

    NASA Astrophysics Data System (ADS)

    Ray, R. D.

    2013-12-01

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

  12. Arctic Ocean tides from GRACE satellite accelerations

    NASA Astrophysics Data System (ADS)

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

    2011-11-01

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

  13. 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

  14. Atmospheric Tides over the Pyrenees. Observational study and numerical simulation

    NASA Astrophysics Data System (ADS)

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

    2010-05-01

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

  15. 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.

  16. 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.

  17. 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.

  18. Erratum: Resonant Tides in Close Orbiting Planets

    NASA Astrophysics Data System (ADS)

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

    1999-06-01

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

  19. Tides and the Evolution of Planetary Habitability

    NASA Astrophysics Data System (ADS)

    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 (≲0.35 M⊙). 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, ˜5 M⊕ 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.

  20. 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.

  1. Global charts of ocean tide loading effects

    SciTech Connect

    Francis, O.; Mazzega, P. )

    1990-07-15

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

  2. Improving Coastal Tide Forecasts with Data Assimilation

    NASA Astrophysics Data System (ADS)

    Zaron, E. D.; Smith, S. R.; Martin, P.

    2012-12-01

    A model of the Yellow Sea is used as a prototype for improving tidal water levels in coastal ocean models. An incremental variational data assimilation method has been implemented in which a linear data-assimilative tidal model, OTIS, is used to compute model forcing corrections for a non-linear regional model derived from POM. Both OTIS and the POM-derived model are configured with identical 8km-resolution grids, and OTIS uses a bottom drag formulation linearized around the prior POM solution. Assimilated data consist of satellite altimeter data as well as harmonically analyzed tide gauge data, where half of the latter are withheld for parameter calibration. It is found that M2 tide error is reduced from 21cm to 12cm in the regional model, which compares favorably with the 11cm error for the linear OTIS solution. Smaller constituents are also improved to a lesser degree. In contrast, the alternative approach of using OTIS to provide boundary conditions for the POM-derived model yields M2 tides with an error of 20 to 40cm, depending on the version of the OTIS solution used.

  3. Nonlinear Tides in Close Binary Systems

    NASA Astrophysics Data System (ADS)

    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' >~ 10-100 M ⊕ at orbital periods P ≈ 1-10 days. The nearly static "equilibrium" tidal distortion is, however, stable to parametric resonance except for solar binaries with P <~ 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 ≈ 103[P/10 days] for a solar-type star) and drives them as a single coherent unit with growth rates that are a factor of ≈N faster than the

  4. 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

  5. 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.

  6. Surface manifestation of internal tides generated near Hawaii

    NASA Astrophysics Data System (ADS)

    Ray, Richard D.; Mitchum, Gary T.

    Analysis of Topex/Poseidon satellite altimetry reveals short-wavelength fluctuations in the ocean surface tide that are attributable to internal tides. A significant fraction of the semidiurnal internal tide generated at the Hawaiian Ridge is evidently phase-locked to the astronomical potential and can modulate the amplitude of the surface tide by ∼5 cm. The internal tide is thus easily mapped along satellite groundtracks, and it is found to be spatially coherent over great distances, with waves propagating well over 1000 km from the Hawaiian Ridge before decaying below noise level. Both first and second baroclinic modes are observed in both the M2 (lunar) and S2 (solar) tides. The high space-time coherence is in sharp contrast to what is often inferred from current-meter observations, but it confirms recent speculations from an acoustic experiment north of Hawaii.

  7. 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.

  8. Observations and simulations of the ionospheric lunar tide: Seasonal variability

    NASA Astrophysics Data System (ADS)

    Pedatella, N. M.

    2014-07-01

    The seasonal variability of the ionospheric lunar tide is investigated using a combination of Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) observations and thermosphere-ionosphere-mesosphere electrodynamics general circulation model (TIME-GCM) simulations. The present study focuses on the seasonal variability of the lunar tide in the ionosphere and its potential connection to the occurrence of stratosphere sudden warmings (SSWs). COSMIC maximum F region electron density (NmF2) and total electron content observations reveal a primarily annual variation of the ionospheric lunar tide, with maximum amplitudes occurring at low latitudes during December-February. Simulations of the lunar tide climatology in TIME-GCM display a similar annual variability as the COSMIC observations. This leads to the conclusion that the annual variability of the lunar tide in the ionosphere is not solely due to the occurrence of SSWs. Rather, the annual variability of the lunar tide in the ionosphere is generated by the seasonal variability of the lunar tide at E region altitudes. However, compared to the observations, the ionospheric lunar tide annual variability is weaker in the climatological simulations which is attributed to the occurrence of SSWs during the majority of the years included in the observations. Introducing a SSW into the TIME-GCM simulation leads to an additional enhancement of the lunar tide during Northern Hemisphere winter, increasing the lunar tide annual variability and resulting in an annual variability that is more consistent with the observations. The occurrence of SSWs can therefore potentially bias lunar tide climatologies, and it is important to consider these effects in studies of the lunar tide in the atmosphere and ionosphere.

  9. 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.

  10. 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.

  11. 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.

  12. Eye redness

    MedlinePlus

    Bloodshot eyes; Red eyes; Scleral infection; Conjunctival infection ... There are many causes of a red eye or eyes. Some are medical emergencies and some are a cause for concern, but not an emergency. Others are nothing to worry about. ...

  13. Red Clover

    MedlinePlus

    ... 17):2057–2071. Red clover. Natural Medicines Comprehensive Database Web site. Accessed at www.naturaldatabase.com on July 22, 2009. Red clover ( Trifolium pratense ). Natural Standard Database Web site. Accessed at www.naturalstandard.com on July ...

  14. 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. PMID:18598142

  15. 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.

  16. Global Aerosols

    Atmospheric Science Data Center

    2013-04-19

    ... sizes and from multiple sources, including biomass burning, mineral dust, sea salt and regional industrial pollution. A color scale is ... desert source region. Deserts are the main sources of mineral dust, and MISR obtains aerosol optical depth at visible wavelengths ...

  17. TEACHING PHYSICS: The tides - a neglected topic

    NASA Astrophysics Data System (ADS)

    Härtel, Hermann

    2000-01-01

    The lunar tides are generated by the movement of the Earth through the non-homogeneous gravitational field of the Moon while circling around the centre of mass of the Moon and Earth and simultaneously rotating around its own axis. This truly dynamic system is difficult to explain when the explanation is restricted to print media. Computer simulations, where these processes can be visualized directly, can be used to add value, thus opening new paths for a more distinct analysis and increased learning results.

  18. Red clover

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Red clover (Trifolium pratense L.) is an important forage legume grown on approximately 4 million hectares worldwide. An estimated 2.8 million kg of red clover seed per year was produced worldwide in 2005-2007. This amount of seed would be enough to maintain approximately 4 million hectares of red...

  19. Red Sea

    Atmospheric Science Data Center

    2013-04-16

    article title:  The Red Sea     View Larger Image ... Imaging SpectroRadiometer (MISR) image of the Red Sea was acquired on August 13, 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 algae,  Trichodesmium ...

  20. 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.

  1. Nonlinear Tides in Coalescing Binary Neutron Stars

    NASA Astrophysics Data System (ADS)

    Weinberg, Nevin

    2016-03-01

    Coalescing binary neutron stars are among the most promising sources for ground-based gravitational wave detectors such as Advanced LIGO. Tidal interactions in such systems extract energy from the orbit and, at some level, modify the gravitational wave signal. Previous studies found that tidal effects are probably too small to be detected from individual systems with LIGO. However, these studies typically assumed that the tide can be treated as a linear perturbation to the star. I will show that the linear approximation is invalid even during the early stages of inspiral and that nonlinear fluid effects in the form of tide-internal wave interactions become important around the time the binary first enters LIGO's bandpass (at gravitational wave frequencies around 30 Hz). Although the precise influence of nonlinear fluid effects is not yet well constrained, I will show that they may significantly modify the gravitational wave signal and electromagnetic emission from coalescing binary neutron stars. This research was supported by NASA Grant NNX14AB40G.

  2. 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. PMID:23379951

  3. Research-Based Teaching Unit on the Tides. Research Report

    ERIC Educational Resources Information Center

    Viiri, Jouni; Saari, Heikki

    2004-01-01

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

  4. 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.

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

    EPA Science Inventory

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

  6. 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).

  7. 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.

  8. 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

  9. 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

  10. Estimating Tides from a Planetary Flyby Mission

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

  11. 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.

  12. 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.

  13. 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.

  14. The shaping of continental slopes by internal tides

    USGS Publications Warehouse

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

    2002-01-01

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

  15. The Sea Surface Temperature Variation during the Spring Tide and Neap Tide in the South China Sea

    NASA Astrophysics Data System (ADS)

    Huang, Shih-Jen; Kuo, Nan-Jung; Ho, Chung-Ru; Lo, Yao-Tsai

    2016-04-01

    The sea surface temperature (SST) data of MODIS/Terra (Moderate-resolution Imaging Spectroradiometer) are used to analyze the SST difference between the spring tide and the neap tide in the South China Sea (SCS) from 2001 to 2013. The 4 stations from north to south in the SCS are used to investigate the variation of SST. The results show the lowest SST found on January and the highest SST found on June. The standard deviation of SST in shallow regions (St. 1 and St. 4) are larger than the deep regions (St. 2 and St. 3). During the winter and spring the standard deviation of SST at the neap tide are greater than the spring tide period. From the later winter to early summer, the SST during the neap tide period is greater than the spring tide period. They are more obvious in the shallow regions. Meanwhile the influence of tide action in the shallow regions is greater than it in the deep regions.

  16. 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.

  17. Red Sky with Red Mesa

    ScienceCinema

    None

    2014-06-23

    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.

  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. Lead Isotopic Composition and Trace Metals in Aerosols for Source Apportionment

    NASA Astrophysics Data System (ADS)

    Chien, C. T.; Paytan, A.

    2014-12-01

    Transported thousands of miles away from their source, aerosols can be dispersed and deposition throughout the Earth's surface. Aerosols from natural and industrial sources have different characteristics and health impacts thus it is important to identify their sources. The lead isotopic composition and trace metals in aerosol samples collected in different regions and periods around the world can help us better understand spatial and seasonal variation of aerosol sources. Aerosol samples collected in California, Bermuda, China and the Red Sea have been analyzed. The trace metal and Pb isotopes in these samples provide information regarding the various sources of aerosols to these sites.

  20. Red Capes, Red Herrings, and Red Flags.

    ERIC Educational Resources Information Center

    Fiske, Donald W.

    The argument that the personality structures obtained from retrospective ratings reflect semantic similarity structures has been as provocative as a red cape in the bull ring. High congruence between those two kinds of structures seems well established. What is less clear is how and why those structures differ from that for immediate judgments of…

  1. Numerical Study for Baroclinic Tides Modified By an Oblique Current

    NASA Astrophysics Data System (ADS)

    Wang, C. A.; Jan, S.

    2014-12-01

    Previous investigations suggest that when the internal waves throughout a northwest - southeast background flow, its amplitudes, propagation path, phase speed might be changed. The process occurring when internal tides meet a background geostrophic current at an angle rather than perpendicular to the current in a zonal channel is investigated using a numerical model with simplified forcing, topography and hydrographic setting. We compared numerical results of two different background conditions: (1) no background flow and (2) oblique background flow. Results indicate that the westward baroclinic energy flux tends to increase when internal tides pass through the background geostrophic flow. Different oblique angles of the background flow also cause different responses on the propagation of internal tides. The energy exchange between the internal tides and background flow is analyzed using an energy balance equation as well as the numerical results.

  2. 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.

  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. 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

  5. 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

  6. 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…

  7. 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.

  8. 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.

  9. 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].

  10. Another look at North Sea pole tide dynamics

    NASA Technical Reports Server (NTRS)

    Dickman, S. R.; Preisig, J. R.

    1986-01-01

    The mechanism proposed by Wunsch (1974) to explain pole tide observations in the North Sea is evaluated. Wunsch's equations governing pole tide in the North Sea are presented, and solutions for correcting the depth, stream function, and deviation of the tidal height from the equilibrium values are described. The similarity between the Stokes paradox and the tidal equations of the North Sea, and the need for inclusion of inertial terms in the tidal equations are discussed.

  11. Atmospheric Aerosols

    NASA Technical Reports Server (NTRS)

    Pueschel, R. F.; Lawless, James G. (Technical Monitor)

    1994-01-01

    Aerosols, defined as particles and droplets suspended in air, are always present in the atmosphere. They are part of the earth-atmosphere climate system, because they interact with both incoming solar and outgoing terrestrial radiation. They do this directly through scattering and absorption, and indirectly through effects on clouds. Submicrometer aerosols usually predominate in terms of number of particles per unit volume of air. They have dimensions close to the wavelengths of visible light, and thus scatter radiation from the sun very effectively. They are produced in the atmosphere by chemical reactions of sulfur-, nitrogen- and carbon-containing gases of both natural and anthropogenic origins. Light absorption is dominated by particles containing elemental carbon (soot), produced by incomplete combustion of fossil fuels and by biomass burning. Light-scattering dominates globally, although absorption can be significant at high latitudes, particularly over highly reflective snow- or ice-covered surfaces. Other aerosol substances that may be locally important are those from volcanic eruptions, wildfires and windblown dust.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Differences between mean tide level and mean sea level

    NASA Astrophysics Data System (ADS)

    Woodworth, P. L.

    2016-07-01

    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.

  20. 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.

  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. 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.

  3. 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).

  4. 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).

  5. 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.

  6. 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.

  7. Tidal asymmetry in estuaries with mixed semidiurnal/diurnal tides

    NASA Astrophysics Data System (ADS)

    Nidzieko, Nicholas J.

    2010-08-01

    Tidal asymmetry in estuaries with mixed, mainly semidiurnal tides arises from both the interaction of principal tides and the higher harmonics generated by distortions within the estuary. The duration asymmetry in rise and fall of water level caused by principal tides on the west coast of the continental United States is ebb-dominant, and so the tide entering estuaries is also ebb-dominant, prior to any internal distortions within the estuary. The interaction of higher harmonics with principal constituents either augments or cancels the duration asymmetry in the principal tides. In estuaries where tidal elevation and velocity phase are near quadrature (90° out of phase), the duration asymmetry in tidal elevation leads to asymmetries in tidal current magnitude. Asymmetry can be conveniently quantified in terms of the sample skewness, γ1, the normalized third sample moment about the mean. An analytic approximation to the skewness shows that traditional metrics of asymmetry, namely the ratio of constituent amplitudes and the relative constituent phase difference, arise from calculating the third sample moment. Observations from three California estuaries of different morphologies are presented as an illustration of how skewness can be used to quantify asymmetry in real systems. As in semidiurnal systems, morphology is a good predictor of whether higher harmonics engender ebb-dominance or flood-dominance, however asymmetry imposed by principal tides at the mouth must first be overcome and so there is a spatial evolution in the total asymmetry. Quantifying observations via skewness should be considered in addition to traditional metrics in estuaries with mixed tides.

  8. 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.

  9. 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.

  10. 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.

  11. Tides on Self-gravitating, Compressible Bodies

    NASA Astrophysics Data System (ADS)

    Hurford, T. A.; Greenberg, R.

    2001-11-01

    Most modern derivations of tidal amplitude follow the approach presented by Love [1]. Love's analysis for a homogeneous sphere assumed an incompressible material, which required introduction of a non-rigorously justified pressure term. We have solved the more general case of arbitrary compressibility, which allows for a more straightforward derivation [2,3]. We find the h2 love number of a body of radius R, density ρ , by solving the deformation equation [4], μ ∇ 2 u = ρ ∇U - (λ + μ ) ∇ (∇ ṡ u) where μ is the rigidity of the body and λ the Lamé constant. The potential U is the sum of (a) the tide raising potential, (b) the potential of surface mass shifted above or below the spherical surface, (c) potential due to the internal density changes and (d) the change in potential of each bit of volume due to its displacement u. A self-consistent solution can be obtained with U = \\sum_{q=0}^{\\infty} b_{(2+2q)} r^{(2+2q)} ( {3}/{2} \\cos2 \\theta - {1}/{2} ). In [1] and [3] only the r2 term was considered, which was valid only if compressibility is small or elasticity governs deformation (i.e. ρ g R << (λ + 2 μ )). The solution with only the r2 term reduces to Love's [1] solution in the limit of zero compressibility (λ = ∞ ). However, for rock μ ~ λ [4], in which case h2 is enhanced by ~ 3 %, and solutions for greater compressibility give up to 8 % enhancement of tidal amplitude. If ρ g R is significant, higher order r(2q+2) terms are important and even greater corrections are required to the classical tidal amplitude. [1] Love, A.E.H., New York Dover Publications, 1944 [2] Hurford, T.A. and R. Greenberg, Lunar Plan. Sci. XXXII 1741, 2001 [3] Hurford, T.A. and R. Greenberg, 2001 DDA meeting, Bull. Amer. Astron. Soc. in press [4] Kaula, W.M., John Wiley & Sons, Inc., 1968

  12. Seasonal Variations in Pluto's Atmospheric Tides

    NASA Astrophysics Data System (ADS)

    French, R. G.; Toigo, A. D.; Sicardy, B.; Guzewich, S.; Gierasch, P. J.; Richardson, M. I.

    2013-12-01

    Pluto's tenuous atmosphere exhibits remarkable dynamical activity and seasonal change as a result of the substantial tilt of its rotational axis and its highly elliptical orbit. Early discovery observations by stellar occultation (Elliot et al. 1989 Icarus 77, 148) revealed a relatively symmetrical atmosphere of very low density, with evidence of either a near-surface haze layer or a very cold near-surface layer. Later occultation and spectroscopic measurements showed that the dominant constituent of the atmosphere is nitrogen, with lower abundances of CH4 and other trace amounts of greenhouse gases that control the thermal structure of the middle atmosphere. Over the past two decades, occultations have convincingly demonstrated that the atmospheric pressure on Pluto has increased substantially, perhaps by a factor of 2 to 4, as the planet has moved from equinox towards solstice conditions. These data have also shown an interesting change in dynamical activity in the atmosphere, as revealed by "spikes" in the occultation light curves resulting from refractive focussing by atmospheric waves. In the past two years, a conspicuous asymmetry in wavelike activity has become evident, being much stronger in the winter hemisphere than in the summer. Toigo et al. (2010, Icarus 208, 402) explored the possibility that these waves are caused by solar-induced sublimation and diurnal freezing from N2 frost patches -- weak vertical winds are induced by the rising and sinking gas as it is release from or condenses on the surface. Using a variant of this tidal model, we explore the expected strength and regional characteristics of tides over the course of Pluto's orbit, accounting for changes in insolation and distance from the sun, for a variety of assumed spatial distributions of surface frost. Using a 3-D time-dependent ray-tracing code we compute model light curves for the actual circumstances of several recent occultations, and compare the character of the scintillations in the

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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).

  18. 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.

  19. Barotropic tides in the global oceans from a nonlinear tidal model assimilating altimetric tides. 2. Altimetric and geophysical implications

    NASA Astrophysics Data System (ADS)

    Kantha, Lakshmi H.; Tierney, Craig; Lopez, Joseph W.; Desai, Shailen D.; Parke, Michael E.; Drexler, Laura

    1995-12-01

    In this second part, we explore the implications of the tides derived from the high-resolution, data-assimilative, nonlinear barotropic global ocean tidal model described by Kantha (this issue) in altimetric analysis and geophysical applications. It is shown that when applied to the task of removing tidal sea surface height from TOPEX altimetric records, the model performance is comparable to other global tidal models in the open ocean as measured by the reduction in crossover variances. The performance is slightly better than that of the only other high-resolution global tidal model from Grenoble (Le Provost et al., 1994). The results are however mixed in regions shallower than 1000 m and in semienclosed seas such as the Bering Sea, with the model performance slightly worse overall than the Grenoble model. Computations of total power input (and hence total tidal dissipation rate) are shown to be in excellent agreement with recent analyses of TOPEX data and geophysical observations. In addition, distributions of the tidal power input, tidal dissipation, and the power fluxes in the global oceans are shown for the two primary constituents, M2 and K1. Load tides in solid Earth due to ocean tidal loading fluctuations are also computed for the major semidiurnal and diurnal constituents. The load tides are shown to be large in the shallow seas adjacent to the coasts with high tides such as the Patagonian shelf, because of the higher resolution of this global tide model. This has potential implications in geophysical applications.

  20. 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.

  1. Remote Sensing Monitoring of Tide Propagation Through Coastal Wetlands

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

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

  2. 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

  3. 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.

  4. 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 ...

  5. 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

  6. 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

  7. Observational Study on the Internal Tides in the Northern South China Sea

    NASA Astrophysics Data System (ADS)

    Liang, H.; Tian, J.; Zhao, W.

    2015-12-01

    South China Sea (SCS) is the largest marginal sea of the western north Pacific. Due to the interaction between the abrupt topography at the Luzon Strait (LS) and the barotropical tides, internal tides (ITs) are active in the northern SCS. Therefore, to clarify the temporal variations and spatial distributions of the internal tides in the northern SCS, and to investigate the propagation and evolution of internal tides and its contributions to the deep ocean mixing, a mooring array with up to 11 moorings has been built in the northern SCS since 2010. Based on continuous observations for 5 years, a series of studies are conducted here, to analyze the temporal variability and spatial structure of the internal tides in the SCS, to describe the propagation paths of the internal tides in the SCS, to explore the influence of barotropical tides at LS to the internal tides in the northern SCS, and to quantify the contributions of the internal tides to deep ocean mixing in the northern SCS. A series of research results are as follows: In the northern SCS, the diurnal tide kinetic energy is found to exhibit apparent seasonal variability—strongest in summer and weakest in autumn and spring. However, the variability of semidiurnal tide is just opposite, but with smaller amplitude. It is further found that the barotropical tide and the diurnal internal tide observed at the generation site also display a similar seasonal variation with diurnal internal tides in northeast SCS, which indicates that the barotropical tidal current at the source region has the potential to account for the seasonal variability of the diurnal tide on the continental slope of the northern SCS. During the westward propagation from LS to the continental slope and shelf in the SCS, the energy proportion of higher mode internal waves are increasing for diurnal tide, but decreasing gradually for semidiurnal tide. The internal tides are propagating away from the Luzon Strait, with the diurnal internal tides

  8. Modelling of tide and surge elevations in the Solent and surrounding waters: The importance of tide-surge interactions

    NASA Astrophysics Data System (ADS)

    Quinn, Niall; Atkinson, Peter M.; Wells, Neil C.

    2012-10-01

    A regional two-dimensional hydrodynamic model using the MIKE-21 software and data from a pre-operational forecasting system of the English Channel is described and applied to the Solent-Southampton Water estuarine system. The regional model was able to predict surge heights with a root mean squared error (RMSE) accuracy of 0.09 m during a three month hindcast in the winter of 2009, comparing closely with accuracy assessments from other independent systems. However, consistent underprediction of tidal harmonic constituent amplitudes was present throughout the region leading to errors in the prediction of the total water level elevations. Despite the complex nature of the Solent tidal regime, interpolation of tidal elevations from harmonic analysis at fixed tide gauge locations was shown to be effective in reducing this uncertainty at gauged and un-gauged sites. The degree to which tide-surge interactions were taking place was examined. Of particular interest was the quantification of the sensitivity of the predicted surge to the levels of uncertainty expected in the prediction of the tide within a complex nearshore region such as the Solent. The tide-surge interaction during three surge events was shown to be greatest in the Western Solent and Southampton Waters regions, where the tidal uncertainty was greatest. Interaction between the tide and surge resulted in a change of up to 0.3 m (11%) in the predicted total peak water level when the surge was added to the harmonic analysis-based tidal prediction. Despite the significant effect of removing the tide-surge interactions, tests indicated that the error in tidal range expected in the regional models tidal prediction altered the prediction of the surge only enough to induce changes in peak total water elevations by up to 0.03 m during an event on 10th March 2008. The findings suggest that the current tidal predictions in complex estuarine systems, such as the Solent, are of high enough quality to reproduce the

  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. 75 FR 51987 - TideWorks, LLC; Notice of Application Ready for Environmental Analysis, Soliciting Comments...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-24

    ... Energy Regulatory Commission TideWorks, LLC; Notice of Application Ready for Environmental Analysis....: 13656-000. c. Date Filed: January 15, 2010. d. Applicant: TideWorks, LLC. e. Name of Project: TideWorks... comments were filed regarding scoping. With this notice we are waiving scoping for the proposed...

  11. 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…

  12. Coordinated radar observations of atmospheric diurnal tides in equatorial regions

    NASA Astrophysics Data System (ADS)

    Tsuda, Toshitaka; Ohnishi, Kazunori; Isoda, Fusako; Nakamura, Takuji; Vincent, Robert A.; Reid, Iain M.; Harijono, Sri Woro B.; Sribimawati, Tien; Nuryanto, Agus; Wiryosumarto, Harsono

    1999-07-01

    The long-term behavior of atmospheric tides in the mesosphere and lower thermosphere has been observed with the meteor wind radar (MWR) in Jakarta, Indonesia (6°S, 107°E) from November 1992 to August 1997. The amplitudes and phases of the diurnal tides show systematic seasonal variations, particularly distinct in the meridional component. In addition, substantial interannual variability is evident, characterized by a biennial periodicity of tidal parameters, and considerably small tidal amplitudes exclusively seen in 1996. The MWR results are compared with the Global Scale Wave Model (GSWM) as well as MF radar data collected in two equatorial sites in Pontianak (0.03°N, 109°E) and Christmas Island (2°N, 158°W) for November 1995-July 1997 and January 1996-October 1997, respectively. Comparison studies of these radar data have revealed the detailed latitudinal structure of the diurnal tide near the equator. The GSWM has successfully described the general characteristics of the radar results, although some discrepancies are recognized. In 1996 when radar data are available at all the three sites, the monthly mean values of tidal amplitudes at 90 km agreed very well between Jakarta and Pontianak, while significant discrepancy was found for Christmas Island, suggesting the existence of geographical effects such as non-migrating tides.

  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. Tide and skew surge independence: New insights for flood risk

    NASA Astrophysics Data System (ADS)

    Williams, Joanne; Horsburgh, Kevin J.; Williams, Jane A.; Proctor, Robert N. F.

    2016-06-01

    Storm surges are a significant hazard to coastal communities around the world, putting lives at risk and costing billions of dollars in damage. Understanding how storm surges and high tides interact is crucial for estimating extreme water levels so that we can protect coastal communities. We demonstrate that in a tidal regime the best measure of a storm surge is the skew surge, the difference between the observed and predicted high water within a tidal cycle. Based on tide gauge records spanning decades from the UK, U.S., Netherlands, and Ireland we show that the magnitude of high water exerts no influence on the size of the most extreme skew surges. This is the first systematic proof that any storm surge can occur on any tide, which is essential for understanding worst-case scenarios. The lack of surge generation dependency on water depth emphasizes the dominant natural variability of weather systems in an observation-based analysis. Weak seasonal relationships between skew surges and high waters were identified at a minority of locations where long-period changes to the tidal cycle interact with the storm season. Our results allow advances to be made in methods for estimating the joint probabilities of storm surges and tides.

  15. 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.

  16. 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

  17. 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

  18. 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

  19. 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

  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. 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…

  2. Effects of thermal tides on the Venus atmospheric superrotation

    NASA Astrophysics Data System (ADS)

    Takagi, M.; Matsuda, Y.

    2007-08-01

    A nonlinear dynamical model on the sphere has been constructed to investigate a generation mechanism of the Venus atmospheric superrotation by the thermal tides. By using the solar heating exciting the diurnal and semidiurnal tides, the atmospheric superrotation extending from the ground to 80 km is generated. The vertical distributions of the mean zonal flow obtained in our numerical experiments are similar to the observations. The maximum velocity of the mean zonal flow reaches about 60-100 m/s near the cloud top level. A linear theory proposed by Takagi and Matsuda (2006) suggests that the atmospheric superrotation obtained in the present study is generated and maintained by the momentum transport associated with the thermal tides. Namely, the downward transport of zonal momentum associated with the downward propagating semidiurnal tide excited in the cloud layer induces the mean zonal flow opposite to the Venus rotation in the lowest layer adjacent to the ground. Surface friction acting on this counter flow provides the atmosphere with the net angular momentum from the solid part of Venus.

  3. Influence analysis of Arctic tide gauges using leverages

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

  4. Wind stress forcing of the North Sea `pole tide'

    NASA Astrophysics Data System (ADS)

    O'Connor, William P.; Chao, Benjamin Fong; Zheng, Dawei; Au, Andrew Y.

    2000-08-01

    We conduct numerical simulations of the wind forcing of sea level variations in the North Sea using a barotropic ocean model with realistic geography and bathymetry to examine the forcing of the 14 month `pole tide', which is known to be anomalously large 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 ocean model output sea level response is then compared with 10 coastal tide gauge records from the Permanent Service for Mean Sea Level (PSMSL) over the same period of time. Besides the strong seasonal variations, several prominent quasi-periodicities exist near 7 years, 3 years, 14 months, 9 months and 6.5 months. Correlations 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 set-up response to wind stress forcing with a periodicity of around 14 months. We find no need to invoke a geophysical explanation involving resonance enhancement of the pole tide in the North Sea to explain the observations.

  5. Regional ocean tide loading modelling around the Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Benavent, M.; Arnoso, J.; Montesinos, F. G.

    2009-12-01

    We developed a new 1/12° resolution oceanic tide model in the complex region that surrounds the Iberian Peninsula. The model, named IBER01, allows us to obtain more accurate tidal loading computations for precise geodetic and gravimetric observations in this area. The modelling follows the scheme of data assimilation (coastal tide gauge, bottom pressure sensors and TOPEX/Poseidon altimetry) into a hydrodynamical model, which is based on two-dimensional barotropic depth averaged shallow-water equations. Detailed bathymetry data and quadratic bottom friction with a specific drag coefficient for the region have been considered. Improved ocean load maps for the Iberian Peninsula are obtained for eight harmonic constituents (Q1, P1, O1, K1, N2, M2, S2 and K2), after computing the load effect (Newtonian attraction and elastic contribution) using IBER01 and six present-day global oceanic tide models for comparison. The results achieved verify the quality of the new model. Our ocean loading computations reduce considerably the discrepancies between the theoretical Earth tide parameters and those from observations at the level of 0.3%.

  6. 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

  7. Hydrography of a hypersaline coastal lagoon in the Red Sea

    NASA Astrophysics Data System (ADS)

    Meshal, Amin H.

    1987-02-01

    Temporal and spatial variations in salinity, temperature, oxygen and pH were studied in a coastal lagoon located on the eastern coast of the Red Sea during 11 cruises taken in the period from May 1983 through April 1984. The lagoon has an area of about 30 km 2 and a maximum depth of about 3 m. The study showed that the water in the lagoon had a very high salinity that varied between 51‰ in February to 113‰ in October and was believed to reach higher values in summer. Rapid fluctuations in salinity were observed in the lagoon especially in positions near its mouth due to the daily exchange of water with the Red Sea accompanying the tides. During high tide, a layer of relatively cold and low salinity water from the Red Sea entered the lagoon and spread over its warmer and more saline water. This led to the existence of a strong vertical stratification in this shallow lagoon. During low tide, the subsurface warm and high salinity water was exposed resulting in the existence of one layer of water in the lagoon. Temporal variation of salinity was correlated with the monthly changes of the mean sea level of the Red Sea and with evaporation. Spatial variations in this property at any position in the lagoon depended upon its location from the mouth of the lagoon. Temperature variation was controlled by meteorological conditions in the region and by the volume of the water in the lagoon. The marine environment of this lagoon is under natural stress due to its high temperature and to the extreme fluctuations of its high salinity. This can be reduced by increasing the rate of exchange of water between the lagoon and the Red Sea.

  8. 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.

  9. 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

  10. Quality assessment of altimeter data through tide gauge comparisons

    NASA Astrophysics Data System (ADS)

    Prandi, Pierre; Valladeau, Guillaume; Ablain, Michael; Picot, Nicolas; Desjonquères, Jean-Damien

    2015-04-01

    Since the first altimeter missions and the improvements performed in the accuracy of sea surface height measurements from 1992 onwards, the importance of global quality assessment of altimeter data has been increasing. Global CalVal studies usually assess this performance by the analysis of internal consistency and cross-comparison between all missions. The overall quality assessment of altimeter data can be performed by analyzing their internal consistency and the cross-comparison between all missions. As a complementary approach, tide gauge measurements are used as an external and independent reference to enable further quality assessment of the altimeter sea level and provide a better estimate of the multiple altimeter performances. In this way, both altimeter and tide gauge observations, dedicated to climate applications, require a rigorous quality control. The tide gauge time series considered in this study derive from several networks (GLOSS/CLIVAR, PSMSL, REFMAR) and provide sea-level heights with a physical content comparable with altimetry sea level estimates. Concerning altimeter data, the long-term drift assessment can be evaluated thanks to a widespread network of tide gauges. Thus, in-situ measurements are compared with altimeter sea level for the main altimeter missions. If altimeter time series are long enough, tide gauge data provide a relevant estimation of the global Mean Sea Level (MSL) drift calculated for all the missions. Moreover, comparisons with sea level products merging all the altimeter missions together have also been performed using several datasets, among which the AVISO delayed-time Sea Level Anomaly grids.

  11. The Impact of Ocean Tides on a Climate Model Simulation.

    NASA Astrophysics Data System (ADS)

    Mueller, M.; Haak, H.; Jungclaus, J.; Thomas, M.

    2008-12-01

    We explicitly include the forcing of ocean tides in a global ocean general circulation model (OGCM). The tidal forcing is deduced from lunisolar ephemerides according to the instantaneous positions of moon and sun. In this real-time approach we consider the complete lunisolar tides of second degree. The OGCM is part of a state-of-the-art climate model which was used for the fourth assessment report simulations of the Intergovernmental Panel on Climate Change (IPCC). An ensemble of five IPCC A1B climate scenarios covering the period 1860 to 2059 has been computed. The induced tidal currents affect the ocean circulation by nonlinear interaction and through vertical mixing. The latter is described in the model by a Richardson number dependent mixing term. Thus, mixing depends on the density stratification and the vertical velocity shear. In regions of high tidal velocities the vertical velocity shear is enhanced in the deepest layers induced by bottom friction. Our study focuses on the North Atlantic region, where the highest tidal velocities occur. There, the representation of the present state of the ocean is improved significantly. The tides adjust the pathway of the North Atlantic Current, which leads to improved sea surface temperatures of up to 3 degree in the North Atlantic. Further, the simulation of the deep convection in the Labrador Sea, one of the driving mechanisms of the meridional overturning circulation, becomes more realistic when forcing ocean tides. The modified oceanic dynamics in the North Atlantic have implications for the simulation of the European climate and for the future projection of the sea surface temperature of the North Atlantic. This study reveals that ocean tides are an important component in the simulation of ocean dynamics and are essential for an appropriate simulation of a changing ocean under climate warming conditions.

  12. 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.

  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. PMID:25972565

  15. 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).

  16. 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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  18. 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...

  19. Aerosols and environmental pollution

    NASA Astrophysics Data System (ADS)

    Colbeck, Ian; Lazaridis, Mihalis

    2010-02-01

    The number of publications on atmospheric aerosols has dramatically increased in recent years. This review, predominantly from a European perspective, summarizes the current state of knowledge of the role played by aerosols in environmental pollution and, in addition, highlights gaps in our current knowledge. Aerosol particles are ubiquitous in the Earth’s atmosphere and are central to many environmental issues; ranging from the Earth’s radiative budget to human health. Aerosol size distribution and chemical composition are crucial parameters that determine their dynamics in the atmosphere. Sources of aerosols are both anthropogenic and natural ranging from vehicular emissions to dust resuspension. Ambient concentrations of aerosols are elevated in urban areas with lower values at rural sites. A comprehensive understanding of aerosol ambient characteristics requires a combination of measurements and modeling tools. Legislation for ambient aerosols has been introduced at national and international levels aiming to protect human health and the environment.

  20. A severe red tide (Tampa Bay, 2005) causes an anomalous decrease in biological sound

    PubMed Central

    Indeck, Katherine L.; Simard, Peter; Gowans, Shannon; Lowerre-Barbieri, Susan; Mann, David A.

    2015-01-01

    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. PMID:26473055

  1. 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 ...

  2. [The red tide caused by the dinoflagellate Alexandrium tamarense in the Colombian Pacific coast (2001)].

    PubMed

    García-Hansen, Ingrid; Cortés-Altamirano, Roberto; Sierra-Beltrán, Arturo P

    2004-09-01

    From April 26th to May 15th 2001, a large algae bloom was observed off Tumaco Bay on the Pacific coast of Colombia. This was the first harmful algae bloom (HAB) reported in the region, and reached Gorgona Island, about 120 km north. A year later, starting March 2002, an offshore HAB developed from Cabo Corrientes North to Solano Bay. The typical abundance during the blooms reached 7.5 x 10(6) cells l(-1) for the 2001 event and 1.6 x 10(6) cells l(-1) for the 2002 event. During both events, low temperature and high salinity were recorded. Typical measurements in the area are 27-27.5 degrees C and 30-31.5 psu. Values observed during the two events were 24-24.6 degrees C and 33-34 psu; 3 degrees C below normal and more than 2.5 psu above average values. These conditions are indicative of local upwelling processes at the time of the events. On both occasions, cells corresponding to the Alexandrium catenella/fundeyense/tamarense complex represented 99-100% of the biomass. It was difficult to differentiate the cells from A. catenella, but the presence of short chains of only 4 cells (single cells represented most of the biomass) was suggestive of A. tamarense. Shape, dimensions, and detailed structure of the apical pore complex, first apical plate, posterior sulcal plate, and position of the ventral pore on plate 1' of cells were consistent with the description of A. tamarense, which has not been reported in the tropical East Pacific. The Control Center of Pacific Contamination of the Maritime General Direction of the Colombian Navy has been monitoring the area since 1994 without finding this species or HABs. This leads us to consider the two events as caused by recently introduced species, where local upwelling processes favor permanent and cyclic HABs. However, during these two events, there were no reports of effects on marine biota or of human poisoning, probably because the blooms occurred some distance offshore and far from exploited shellfish beds. PMID:17465118

  3. Heat wave brings an unprecedented red tide to San Francisco Bay

    USGS Publications Warehouse

    Cloern, James E.; Schraga, Tara S.; Lopez, Cary B.

    2005-01-01

    However, the authors have never observed a dinoflagellate bloom of this scale during 28 years of sampling in the nutrient-rich San Francisco Bay. Phytoplankton biomass along this transect is typically <5mg Chla/m3, and has never exceeded 21 mg Chla/m3 during summer-autumn.

  4. BIOMARKER LIPIDS IN RED TIDE (GYMNODINIUM BREVE) BLOOMS ALONG THE NORTHWEST FLORIDA COAST

    EPA Science Inventory

    The ability to characterize phytoplankton communities and algal blooms using lipids as biomarkers requires knowledge of their distribution and taxonomic significance. Such an approach would have application, for example, in distinguishing and tracking certain dinoflagellates suc...

  5. PHYTOPLANKTON COMPETITION ON THE WEST FLORIDA SHELF: A SIMULATION ANALYSIS WITH "RED TIDE" IMPLICATIONS. (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...

  6. 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...

  7. 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. PMID:26473055

  8. Stemming the Red Tide: Free Speech and Immigration Policy in the Case of Margaret Randall.

    ERIC Educational Resources Information Center

    Parry-Giles, Trevor

    1988-01-01

    Examines the conflict between the First Amendment and immigration policy and law (particularly the 1952 McCarran-Walter Immigration and Nationality Act), as seen in the case against Margaret Randall (an alien facing deportation from the U.S. because of her pro-leftist writings) by the Immigration and Naturalization Service. (SR)

  9. A novel thiazolidinedione derivative TD118 showing selective algicidal effects for red tide control.

    PubMed

    Wu, Ying; Lee, Yew; Jung, Seul-Gi; Kim, Minju; Eom, Chi-Yong; Kim, Si Wouk; Cho, Hoon; Jin, Eonseon

    2014-05-01

    Thiazolidinedione (TD) derivatives have been found to have an algicidal effect on harmful algal bloom microalgae. In this study, 75 TD derivatives were synthesized and analyzed for algicidal activity. Among these synthetic TDs, 18 TD derivatives showed specific algicidal activity on two strains belonging to the classes Raphidophyceae (Chattonella marina and Heterosigma akashiwo) and Dinophyceae (Cochlodinium polykrikoides). Two strains belonging to Bacillariophyceae (Navicula pelliculosa and Phaeodactylum EPV), one strain belonging to Dinophyceae (Amphidinium sp.), and a Eustigmatophycean microalga (Nannochloropsis oculata) showed less sensitivity to the TD derivatives than the other two phyla. The most reactive TD derivative, compound 2 (TD118), was selected and tested for morphological and physiological changes. TD118 effectively damaged the cell membrane of C. marina, H. akashiwo and C. polykrikoides. The O₂ evolution and photosystem II efficiency (F(v)/F(m)) of C. marina, H. akashiwo and C. polykrikoides were also severely reduced by TD118 treatment. Amphidinium sp., N. pelliculosa, Phaeodactylum EPV and N. oculata showed less reduction of O₂ evolution and the F(v)/F(m) by TD118. These results imply that the species-specific TD structure relationship may be due to structural and/or physiological differences among microalgal species. PMID:24374490

  10. Characterization of an epoxide hydrolase from the Florida red tide dinoflagellate, Karenia brevis.

    PubMed

    Sun, Pengfei; Leeson, Cristian; Zhi, Xiaoduo; Leng, Fenfei; Pierce, Richard H; Henry, Michael S; Rein, Kathleen S

    2016-02-01

    Epoxide hydrolases (EH, EC 3.3.2.3) have been proposed to be key enzymes in the biosynthesis of polyether (PE) ladder compounds such as the brevetoxins which are produced by the dinoflagellate Karenia brevis. These enzymes have the potential to catalyze kinetically disfavored endo-tet cyclization reactions. Data mining of K. brevis transcriptome libraries revealed two classes of epoxide hydrolases: microsomal and leukotriene A4 (LTA4) hydrolases. A microsomal EH was cloned and expressed for characterization. The enzyme is a monomeric protein with molecular weight 44kDa. Kinetic parameters were evaluated using a variety of epoxide substrates to assess substrate selectivity and enantioselectivity, as well as its potential to catalyze the critical endo-tet cyclization of epoxy alcohols. Monitoring of EH activity in high and low toxin producing cultures of K. brevis over a three week period showed consistently higher activity in the high toxin producing culture implicating the involvement of one or more EH in brevetoxin biosynthesis. PMID:26626160

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Tropopsheric Aerosol Chemistry via Aerosol Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Worsnop, Douglas

    2008-03-01

    A broad overview of size resolved aerosol chemistry in urban, rural and remote regions is evolving from deployment of aerosol mass spectrometers (AMS) throughout the northern hemisphere. Using thermal vaporization and electron impact ionization as universal detector of non-refractory inorganic and organic composition, the accumulation of AMS results represent a library of mass spectral signatures of aerosol chemistry. For organics in particular, mass spectral factor analysis provides a procedure for classifying (and simplifying) complex mixtures composed of the hundreds or thousands of individual compounds. Correlations with parallel gas and aerosol measurements (e.g. GC/MS, HNMR, FTIR) supply additional chemical information needed to interpret mass spectra. The challenge is to separate primary and secondary; anthropogenic, biogenic and biomass burning sources - and subsequent - transformations of aerosol chemistry and microphysics.

  17. 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.

  18. 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.

  19. Initial results from new Northern Cascadia tide gauge network

    NASA Astrophysics Data System (ADS)

    Vincent, P.; Weldon, R. J.; Livelybrooks, D.; Schmidt, D. A.; Alba, S.; Maciel, T.; Bug, J.; Croes, B.

    2010-12-01

    The Cascadia Slow Earthquake Temporary Tide Gauge (CASSETT) Network is a temporary network of 10 tide gauges deployed during the summer of 2010 in NW Washington along the Strait of Juan de Fuca, Puget Sound, and the Washington coast at historical but now unoccupied NOAA tide gauge sites. The purpose of this deployment is to densify the existing network of NOAA tide gauge sites to resolve small tectonic uplift signals associated with the 2010 slow slip event that began in August 2010 under the Olympic Peninsula. This particular (14-month cycle) event was chosen because it was expected, correctly, to occur during the summer (which will not recur for another 7+ years) when ocean noise from storm activity is at a minimum, enabling adequate removal of tidal and ocean noise signals to recover the small (a few millimeters) vertical tectonic signals from the slow slip event. Determining the vertical component of deformation is important because it is more sensitive to variations in locking depth of the megathrust zone than the horizontal component, and because the signal-to-noise ratio of the vertical component of GPS time series data is too low to resolve these events. In addition, Alba, et al, 2009 observed a slow slip uplift signal from the September, 2005 event in the data from the Port Angeles and Port Townsend NOAA tide gauge stations after removing tidal and ocean noise signals and stacking the data to lower the noise threshold to a minimum. The data from our network will be combined with data from the existing NOAA (permanent) stations to better resolve the vertical uplift signal from this summer’s slow slip event. A comparison with GPS and strainmenter network data will help us determine the utility of using tidal time series data to measure the vertical deformation from slow slip events. Here we will detail the deployment of this network, which involved undergraduate students participating in the University of Oregon UCORE (Undergraduate Catalytic Outreach and

  20. 75 FR 5070 - TideWorks, LLC; Notice of Application Tendered for Filing With the Commission and Soliciting...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-01

    ... Energy Regulatory Commission TideWorks, LLC; Notice of Application Tendered for Filing With the.... Applicant: TideWorks, LLC. e. Name of Project: TideWorks Project. f. Location: On the Sasanoa River adjacent... for environmental analysis at this time. n. Description of Project: The TideWorks Project...

  1. 75 FR 32450 - TideWorks, LLC; Notice of Application Accepted for Filing, Soliciting Motions To Intervene and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-08

    ... Energy Regulatory Commission TideWorks, LLC; Notice of Application Accepted for Filing, Soliciting...: January 15, 2010. d. Applicant: TideWorks, LLC. e. Name of Project: TideWorks Project. f. Location: On the... requested additional information from TideWorks, LLC including project operation, water velocity,...

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

    NASA Astrophysics Data System (ADS)

    Vergnolle, M.; Bouin, M.-N.; Morel, L.; Masson, F.; Durand, S.; Nicolas, J.; Melachroinos, S. A.

    2008-05-01

    Ocean loading effects cause 3-D displacements large enough to affect space geodesy measurements either at the subdiurnal periods or at longer time scales by the means of spurious signals. GPS measurements, in turn, could provide local improvements of the models in coastal areas if their ability to precisely monitor such rapid displacements is assessed. In this paper, we use 105 days of continuous GPS measurements collected in 2004 in the French Brittany and Cotentin region to investigate: (1) the precision achieved by the GPS analysis on measuring 3-D subdiurnal displacements and amplitude and phase of the tidal constituents, (2) the quality of the most recent ocean tide model FES2004 in such a complex coastal context. Indeed, in this area, tide amplitudes are among the largest in the world (up to 16 cm of loading displacements on the vertical component) and are believed to show strong shallow-water tides. From a state of the art GPS analysis using the scientific GAMIT software over 2-h sessions, we test two independent strategies for the realization of the reference frame. The position time series are then compared with the displacements predicted by the FES2004 model applied on an elastic Earth model. The two sets of results are consistent with each other at the same level of agreement than with the predicted displacements, namely 3-5 mm on the horizontal components, 10 mm on the vertical. This assesses the capability of this technique for measuring 3-D ocean tide loading deformation. We validate the FES2004 model in the Brittany area, even though it slightly (2-7 mm) underestimates the three components amplitudes. With a harmonic analysis of the observed position time series, we obtain nevertheless an agreement at a submillimetre level for the M2, N2, O1, Q1 tidal constituents and at a millimetre level for the K1 and S2 tidal constituents. Moreover, we can extract a significant M4 load signal at the 95 per cent confidence level from the GPS time series at the

  3. Observing atmospheric tides in Earth rotation parameters with VLBI

    NASA Astrophysics Data System (ADS)

    Girdiuk, Anastasiia; Böhm, Johannes; Schindelegger, Michael

    2015-04-01

    In this study, we assess the contribution of diurnal (S1) and semi-diurnal (S2) atmospheric tides to variations in Earth rotation by analyzing Very Long Baseline Interferometry (VLBI) observations. Particular emphasis is placed on the dependency of S1 and S2 estimates on varying settings in the a priori delay model. We use hourly Earth rotation parameters (ERP) of polar motion and UT1 as determined with the Vienna VLBI Software (VieVS) from 25 years of VLBI observations and we adjust diurnal and semi-diurnal amplitudes to the hourly ERP estimates after disregarding the effect of high-frequency ocean tides. Prograde and retrograde polar motion coefficients are obtained for several solutions differing in processing strategies (with/without thermal deformation, time span of observations, choice of a priori ERP model and celestial pole offsets) and we compare the corresponding harmonics with those derived from atmospheric and non-tidal oceanic angular momentum estimates.

  4. Relative sea levels from tide-gauge records

    SciTech Connect

    Emery, K.O.

    1980-12-01

    Mean annual sea levels at 247 tide-gauge stations of the world exhibit a general rise of relative sea level of about 3 mm/year during the past 40 years. In contrast, general uplift of the land is typical of high northern latitudes, where unloading of the crust by melt of Pleistocene ice sheets is significant. Erratic movements are typical of belts having crustal overthrusting and active volcanism. Short-term (5- and 10-year) records reveal recent changes in rates, but such short time spans may be so influenced by climatic cycles that identification of new trends is difficult, especially with the existing poor distribution and reporting of tide-gauge data.

  5. Does lunisolar gravitational tide affect the activity of animals?

    NASA Astrophysics Data System (ADS)

    Deshcherevskii, A. V.; Sidorin, A. Ya.

    2010-12-01

    Multiyear time series obtained by the continuous instrumental monitoring of the electrical activity (EA) of weakly electric fish Gnathonemus leopoldianus and the motor activity (MA) of the freshwater catfish Hoplosternum thoracatum and the cockroach Blaberus craniifer are compared to the parameters of the lunisolar gravitational tide. These curves are observed to be very similar for a large number of time intervals. However, a more detailed analysis shows this to be only a superficial resemblance caused by the closeness of the periods of diurnal and semidiurnal rhythms of bioindicator activity (the dominant rhythms in EA and MA patterns) and the periods of main gravitational tidal waves. It is concluded that the lunisolar gravitational tide has no significant effect on animal behavior in our experiment.

  6. Characterizing the semidiurnal internal tide off Tasmania using glider data

    NASA Astrophysics Data System (ADS)

    Boettger, Daniel; Robertson, Robin; Rainville, Luc

    2015-05-01

    The spatial structure of the semidiurnal internal tide in the vicinity of Tasmania is characterized using temperature and salinity data from Seaglider and Slocum glider deployments. Wavelet analysis of isopycnal displacements measured by the gliders was used to isolate the semidiurnal internal tide, with a solid signal observed both to the east and to the south of Tasmania. The signal south of Tasmania was attributed to local forcing, while that to the east of Tasmania was found to have propagated from the south east to the north west—a result which supports previous studies indicating the presence of an internal tidal beam originating over the Macquarie Ridge, south of New Zealand. Displacement amplitudes were observed to be amplified in the vicinity of the continental slope, with the incoming tidal beam shown to be both reflected and scattered on the continental slope and shelf, and energy transferred to higher modes.

  7. The enhanced nodal equilibrium ocean tide and polar motion

    NASA Technical Reports Server (NTRS)

    Sanchez, B. V.

    1979-01-01

    The tidal response of the ocean to long period forcing functions was investigated. The results indicate the possibility of excitation of a wobble component with the amplitude and frequency indicated by the data. An enhancement function for the equilibrium tide was postulated in the form of an expansion in zonal harmonics and the coefficients of such an expansion were estimated so as to obtain polar motion components of the required magnitude.

  8. Role of lunar atmospheric tides in thermosphere density

    NASA Astrophysics Data System (ADS)

    Palus, Shannon

    2014-11-01

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

  9. Modeling Tides, Planetary Waves, and Equatorial Oscillations in the MLT

    NASA Technical Reports Server (NTRS)

    Mengel, J. G.; Mayr, H. G.; Drob, D. P.; Porter, H. S.; Bhartia, P. K. (Technical Monitor)

    2001-01-01

    Applying Hines Doppler Spread Parameterization for gravity waves (GW), our 3D model reproduces some essential features that characterize the observed seasonal variations of tides and planetary waves in the upper mesosphere. In 2D, our model also reproduces the large Semi-Annual Oscillation (SAO) and Quasi Biennial Oscillation (QBO) observed in this region at low latitudes. It is more challenging to describe these features combined in a more comprehensive self consistent model, and we give a progress report that outlines the difficulties and reports some success. In 3D, the GW's are partially absorbed by tides and planetary waves to amplify them. Thus the waves are less efficient in generating the QBO and SAO at equatorial latitudes. Some of this deficiency is compensated by the fact that the GW activity is observed to be enhanced at low latitudes. Increasing the GW source has the desired effect to boost the QBO, but the effect is confined primarily to the stratosphere. With increasing altitude, the meridional circulation becomes more important in redistributing the momentum deposited in the background flow by the GW's. Another factor involved is the altitude at which the GW's originate, which we had originally chosen to be the surface. Numerical experiments show that moving this source altitude to the top of the troposphere significantly increases the efficiency for generating the QBO without affecting much the tides and planetary waves in the model. Attention to the details in which the GW source comes into play thus appears to be of critical importance in modeling the phenomenology of the MLT. Among the suite of numerical experiments reported, we present a simulation that produced significant variations of tides and planetary waves in the upper mesosphere. The effect is related to the QBO generated in the model, and GW filtering is the likely cause.

  10. Bottom friction optimization for a better barotropic tide modelling

    NASA Astrophysics Data System (ADS)

    Boutet, Martial; Lathuilière, Cyril; Son Hoang, Hong; Baraille, Rémy

    2015-04-01

    At a regional scale, barotropic tides are the dominant source of variability of currents and water heights. A precise representation of these processes is essential because of their great impacts on human activities (submersion risks, marine renewable energies, ...). Identified sources of error for tide modelling at a regional scale are the followings: bathymetry, boundary forcing and dissipation due to bottom friction. Nevertheless, bathymetric databases are nowadays known with a good accuracy, especially over shelves, and global tide models performances are better than ever. The most promising improvement is thus the bottom friction representation. The method used to estimate bottom friction is the simultaneous perturbation stochastic approximation (SPSA) which consists in the approximation of the gradient based on a fixed number of cost function measurements, regardless of the dimension of the vector to be estimated. Indeed, each cost function measurement is obtained by randomly perturbing every component of the parameter vector. An important feature of SPSA is its relative ease of implementation. In particular, the method does not require the development of tangent linear and adjoint version of the circulation model. Experiments are carried out to estimate bottom friction with the HYbrid Coordinate Ocean Model (HYCOM) in barotropic mode (one isopycnal layer). The study area is the Northeastern Atlantic margin which is characterized by strong currents and an intense dissipation. Bottom friction is parameterized with a quadratic term and friction coefficient is computed with the water height and the bottom roughness. The latter parameter is the one to be estimated. Assimilated data are the available tide gauge observations. First, the bottom roughness is estimated taking into account bottom sediment natures and bathymetric ranges. Then, it is estimated with geographical degrees of freedom. Finally, the impact of the estimation of a mixed quadratic/linear friction

  11. Tides on the Patagonian shelf from the Seasat radar altimeter

    NASA Technical Reports Server (NTRS)

    Parke, M. E.

    1981-01-01

    The purpose of the study described here is to show comparisons between measurements of the sea surface height by the Seasat radar altimeter and tidal elevations based on gauge data along the coast for two passes by the satellite along the shelf. The results provide initial confirmation that tides can be detected in this region by way of satellite altimetry. The study extends a similar presentation by Parke (1980).

  12. Response of well aquifer systems to earth tides: problem revisited

    USGS Publications Warehouse

    Hsieh, P.A.; Bredehoeft, J.D.; Rojstaczer, S.A.

    1988-01-01

    Re-examines Bredehoeft's analysis of earthtide response of water wells. Narasimhan et al suggest that Bredehoeft's analysis is internally inconsistent, that one cannot directly estimate the specific storage, which characterizes the drained behavior of a porous medium, from earth tide response, which is an undrained phenomenon. Here it is shown that Bredehoeft's analysis is internally consistent, and that it is possible to determine the specific storage from undrained loading. -from Authors

  13. GENERAL VIEW LOOKING NORTHEAST ACROSS THE RIVER AT LOW TIDE, ...

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

    GENERAL VIEW LOOKING NORTHEAST ACROSS THE RIVER AT LOW TIDE, FROM JUST BELOW THE CIDER PRESS. VISIBLE IN THIS PHOTOGRAPH ARE THE PILINGS FROM AN EARLIER BOATHOUSE; STRUCTURES FOR LIQUID FUEL STORAGE TO THE RIGHT WITH THE SKYSCRAPERS OF CENTER CITY PHILADELPHIA BEHIND; A RADIO TRANSMISSION TOWER AT CENTER; AND A RAILROAD BRIDGE ACROSS THE SCHUYLKILL RIVER - John Bartram House & Garden, 54th Street & Lindbergh Boulevard, Philadelphia, Philadelphia County, PA

  14. Time-Frequency Analyses of Tide-Gauge Sensor Data

    PubMed Central

    Erol, Serdar

    2011-01-01

    The real world phenomena being observed by sensors are generally non-stationary in nature. The classical linear techniques for analysis and modeling natural time-series observations are inefficient and should be replaced by non-linear techniques of whose theoretical aspects and performances are varied. In this manner adopting the most appropriate technique and strategy is essential in evaluating sensors’ data. In this study, two different time-series analysis approaches, namely least squares spectral analysis (LSSA) and wavelet analysis (continuous wavelet transform, cross wavelet transform and wavelet coherence algorithms as extensions of wavelet analysis), are applied to sea-level observations recorded by tide-gauge sensors, and the advantages and drawbacks of these methods are reviewed. The analyses were carried out using sea-level observations recorded at the Antalya-II and Erdek tide-gauge stations of the Turkish National Sea-Level Monitoring System. In the analyses, the useful information hidden in the noisy signals was detected, and the common features between the two sea-level time series were clarified. The tide-gauge records have data gaps in time because of issues such as instrumental shortcomings and power outages. Concerning the difficulties of the time-frequency analysis of data with voids, the sea-level observations were preprocessed, and the missing parts were predicted using the neural network method prior to the analysis. In conclusion the merits and limitations of the techniques in evaluating non-stationary observations by means of tide-gauge sensors records were documented and an analysis strategy for the sequential sensors observations was presented. PMID:22163829

  15. Secular Changes in the Tide of the Gulf of Maine

    NASA Astrophysics Data System (ADS)

    Ray, R. D.

    2008-12-01

    For the past century the amplitude of the principal semidiurnal lunar tide in the Gulf of Maine has been dramatically increasing. For example, at Eastport, Maine, the trend in M2 amplitude is 13 cm/century, comparable to the rise in mean sea level. At the same time the solar tide S2 has been decreasing. These tidal changes, which occur throughout the entire Gulf, presumably reflect changes in basin configuration--- geometry, depth, or both. Tidal models that account for Holocene sea level rise do predict an amplification of M2, but much smaller than the currently observed trends. An increasing M2 and decreasing S2 could reflect a shift of the gulf's dominant resonant frequency toward M2 and away from S2. This seems unlikely, however, because Garrett and others have shown that the primary resonance of the Gulf of Maine lies near or below the frequency of N2, so any shift should affect M2 and S2 similarly. Preliminary analysis suggests a small perturbation in the Q of the gulf tide, thus pointing to dissipation rather the frequency-shifting as the cause. In addition, the changes in S2 appear to be induced by a far more widespread decrease in S2 amplitudes throughout much of the northeast Atlantic Ocean, extending at least as far as Bermuda. The cause of this is not understood, but radiational effects in S2 can be ruled out because similar changes occur in K2. We review the evidence---primarily from long tide-gauge time series---for these changes in tidal "constants" and the status of our still-incomplete theories of causative mechanisms.

  16. Seeing Red

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This New Horizons image of Jupiter's volcanic moon Io was taken at 13:05 Universal Time during the spacecraft's Jupiter flyby on February 28, 2007. It shows the reddish color of the deposits from the giant volcanic eruption at the volcano Tvashtar, near the top of the sunlit crescent, as well as the bluish plume itself and the orange glow of the hot lava at its source. The relatively unprocessed image on the left provides the best view of the volcanic glow and the plume deposits, while the version on the right has been brightened to show the much fainter plume, and the Jupiter-lit night side of Io.

    New Horizons' color imaging of Io's sunlit side was generally overexposed because the spacecraft's color camera, the super-sensitive Multispectral Visible Imaging Camera (MVIC), was designed for the much dimmer illumination at Pluto. However, two of MVIC's four color filters, the blue and 'methane' filter (a special filter designed to map methane frost on the surface of Pluto at an infrared wavelength of 0.89 microns), are less sensitive than the others, and thus obtained some well-exposed views of the surface when illumination conditions were favorable. Because only two color filters are used, rather than the usual three, and because one filter uses infrared light, the color is only a rough approximation to what the human eye would see.

    The red color of the Tvashtar plume fallout is typical of Io's largest volcanic plumes, including the previous eruption of Tvashtar seen by the Galileo and Cassini spacecraft in 2000, and the long-lived Pele plume on the opposite side of Io. The color likely results from the creation of reddish three-atom and four-atom sulfur molecules (S3 and S4) from plume gases rich in two-atom sulfur molecules (S2 After a few months or years, the S3 and S4 molecules recombine into the more stable and familiar yellowish form of sulfur consisting of eight-atom molecules (S8), so these red deposits are only seen around recently-active Io

  17. Using satellite altimetry and tide gauges for storm surge warning

    NASA Astrophysics Data System (ADS)

    Andersen, O. B.; Cheng, Y.; Deng, X.; Steward, M.; Gharineiat, Z.

    2015-03-01

    The combination of the coarse temporal sampling by satellite altimeters in the deep ocean with the high temporal sampling at sparsely located tide gauges along the coast has been used to improve the forecast of high water for the North Sea along the Danish Coast and for the northeast coast of Australia. For both locations we have tried to investigate the possibilities and limitations of the use of satellite altimetry to capture high frequency signals (surges) using data from the past 20 years. The two regions are chosen to represent extra-tropical and tropical storm surge conditions. We have selected several representative high water events on the two continents based on tide gauge recordings and investigated the capability of satellite altimetry to capture these events in the sea surface height data. Due to the lack of recent surges in the North Sea we focused on general high water level and found that in the presence of two or more satellites we could capture more than 90% of the high water sea level events. In the Great Barrier Reef section of the northeast Australian coast, we have investigated several large tropical cyclones; one of these being Cyclone Larry, which hit the Queensland coast in March 2006 and caused both loss of lives as well as huge devastation. Here we demonstrate the importance of integrating tide gauges with satellite altimetry for forecasting high water at the city of Townsville in northeast Australia.

  18. Thermal Tides and Stationary Waves Revealed by MGS TES

    NASA Technical Reports Server (NTRS)

    Banfield, D.; Conrath, B. J.; Pearl, J. C.; Smith, M. D.; Gierasch, P. J.; P. R. Christensen

    1999-01-01

    Atmospheric temperature retrievals from TES observed radiances make possible the most complete separation of the constituent wave modes evident in Mars atmosphere to date. We use all of the data from the pre-mapping mission phase, which affords good sampling of the diurnal tides and stationary waves. TES retrievals of atmospheric temperature on a grid of pressure levels are the fundamental data set in this study. We then fit this data to selected fourier modes in longitude and time for latitude and L(sub s) bins. From this we have identified the amplitudes and phases of the diurnal and semi-diurnal tides, the first few (gravest) stationary waves and standing waves, as well as an estimate of the zonal and time mean temperature meridional cross sections. These results will be compared with existing models and theory. A possible critical layer for the sun-synchronous diurnal tide may indicate 40 m/s surface zonal wind near 50S for L(sub s) =255-285. Additional information is contained in the original extended abstract.

  19. Modeling the tides of Massachusetts and Cape Cod bays

    USGS Publications Warehouse

    Jenter, H.L.; Signell, R.P.; Blumberg, A.F.

    1993-01-01

    A time-dependent, three-dimensional numerical modeling study of the tides of Massachusetts and Cape Code Bays, motivated by construction of a new sewage treatment plant and ocean outfall for the city of Boston, has been undertaken by the authors. The numerical model being used is a hybrid version of the Blumberg and Mellor ECOM3D model, modified to include a semi-implicit time-stepping scheme and transport of a non-reactive dissolved constituent. Tides in the bays are dominated by the semi-diurnal frequencies, in particular by the M2 tide, due to the resonance of these frequencies in the Gulf of Maine. The numerical model reproduces, well, measured tidal ellipses in unstratified wintertime conditions. Stratified conditions present more of a problem because tidal-frequency internal wave generation and propagation significantly complicates the structure of the resulting tidal field. Nonetheless, the numerical model reproduces qualitative aspects of the stratified tidal flow that are consistent with observations in the bays.

  20. Tide Gauge And Satellite Altimetry Integration For Storm Surge Prediction

    NASA Astrophysics Data System (ADS)

    Andersen, Ole B.; Cheng, Y.; Deng, X.; Steward, M.; Gharinerat, Z.

    2013-12-01

    Integrating coarse temporal sampling by the satellite altimeter in the deep ocean with the high temporal sampling at tide gauges in sparse location along the coast has been used to improve the forecast of high water in the North Sea along the Danish Coast and storm surges along the Northeast coast of Australia. Along with satellite altimetric data, we have tried to investigate high frequency signals (surges) using data from the past 20 years to investigate existence of ability to capture surges in the regions. We have selected several representative high water events on the two continents based on tide gauge recordings and investigated the capability of the satellite altimeters to capture these in the sea surface height. On the European coast we find that when two or more satellites are available we capture more than 90% of the extreme sea level events. In the Great Barrier Reef section of the Northeast Australia, we have investigated several large cyclones causing much destruction when they hit the coast. One of these being the Cyclone Larry, which hit the Queensland coast in March 2006 and caused both losses of lives as well as huge devastation. Here we demonstrate the importance of integrating tide gauges with satellite altimetry for forecasting high water at the city of Townville in North East Australia.

  1. Possible forcing of global temperature by the oceanic tides

    PubMed Central

    Keeling, Charles D.; Whorf, Timothy P.

    1997-01-01

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

  2. Nordic Sea Level - Analysis of PSMSL RLR Tide Gauge data

    NASA Astrophysics Data System (ADS)

    Knudsen, Per; Andersen, Ole

    2015-04-01

    Tide gauge data from the Nordic region covering a period of time from 1920 to 2000 are evaluated. 63 stations having RLR data for at least 40 years have been used. Each tide gauge data record was averaged to annual averages after the monthly average seasonal anomalies were removed. Some stations lack data, especially before around 1950. Hence, to compute representative sea level trends for the 1920-2000 period a procedure for filling in estimated sea level values in the voids, is needed. To fill in voids in the tide gauge data records a reconstruction method was applied that utilizes EOF.s in an iterative manner. Subsequently the trends were computed. The estimated trends range from about -8 mm/year to 2 mm/year reflecting both post-glacial uplift and sea level rise. An evaluation of the first EOFs show that the first EOF clearly describes the trends in the time series. EOF #2 and #3 describe differences in the inter-annual sea level variability with-in the Baltic Sea and differences between the Baltic and the North Atlantic / Norwegian seas, respectively.

  3. Interplay between river discharge and tides in a delta distributary

    NASA Astrophysics Data System (ADS)

    Leonardi, Nicoletta; Kolker, Alexander S.; Fagherazzi, Sergio

    2015-06-01

    The hydrodynamics of distributary channels has tremendous impact on nutrient and dissolved oxygen circulation, transport of sediments, and delta formation and evolution; yet many processes acting at the river-marine interface of a delta are poorly understood. This paper investigates the combined effect of river hydrograph and micro-tides on the hydrodynamics of a delta distributary. As the ratio between river flow to tidal flow increases, tidal flood duration at the distributary mouth decreases, up to the point when flow reversal is absent. Field measurements in a distributary of the Apalachicola Delta, Florida, USA, reveal that, once the flow becomes unidirectional, high-discharge events magnify tidal velocity amplitudes. On the contrary, while the flow is bidirectional, increasing fluvial discharge decreases tidal velocity amplitudes down to a minimum value, reached at the limit between bidirectional and unidirectional flow. Due to the different response of the system to tides, the transition from a bidirectional to a unidirectional flow triggers a change in phase lag between high water and high water slack. In the presence of high riverine flow, tidal dynamics also promote seaward directed Eulerian residual currents. During discharge peaks, these residual currents almost double mean velocity values. Our results show that, even in micro-tidal environments, tides strongly impact distributary hydrodynamics during both high and low fluvial discharge regimes.

  4. Tide-modulated gas emissions and tremors off SW Taiwan

    NASA Astrophysics Data System (ADS)

    Hsu, S.; Wang, S.; Liao, Y.; Lin, J.; Yang, T. F.; Tsai, C.; Chen, S.

    2012-12-01

    Escape of methane and carbon dioxide from the seafloor has great impacts not only on the geosphere but also on the biosphere, the hydrosphere and the atmosphere. However, its mechanism is still poorly understood. For that, we have deployed 8 Ocean bottom Seismometers around an active mud volcano off SW Taiwan. We find that the gas emissions from the seabed and the associated tremors off SW Taiwan are strongly correlated with the ocean tides, especially the diurnal and semi-diurnal constitutes. The daily activity of gas emissions and the intensity of tremors are directly proportional to the daily tidal range. Particularly, for each tidal day the gas emissions and long-duration tremors mainly occur at the rising slopes to the higher high tides and at the falling slopes to the lower low tides. It is then suggested that the upward flow of methane beneath the seabed is more active in those periods. Both the individual tremors and long-duration tremors occur as results of the gas expulsions out of the gas-bearing seabed. High-frequency components of the tremors quickly decay and are followed by low-frequency harmonic oscillations. Long-duration tremors can enhance seafloor instability and increase the potential for submarine landslides.

  5. On the polarization relations of diurnal and semidiurnal tide in the mesopause region

    NASA Astrophysics Data System (ADS)

    She, Chiao-Yao; Krueger, David A.; Yuan, Tao; Oberheide, Jens

    2016-05-01

    The polarization relations for gravity waves are well known and have proven to be very powerful for the investigation of their dynamics. Though tides are sometimes regarded as low-frequency gravity waves, their polarization relations are hardly considered. We derive the polarization relationships of tides from the primitive equations for perturbations of a dissipation-less atmosphere. The vertical wind tide is found to relate directly to temperature tide, independent of tidal structure and geometric location. On the other hand, the relation between meridional wind tide and zonal wind tide is found to depend on the horizontal derivatives of the associated geopotential perturbation, thus depending on tidal structure and geometric location. Lidar observed tides at a local station (tidal period perturbations) in the midlatitude mesopause region (80-105 km) and the Climatological Tidal Model of the Thermosphere (CTMT) based on Hough Mode Extension (HME) technique at the lidar site, both of which include the effect of dissipation, are then compared. These tidal amplitudes and phases are employed to discuss the results and implications of the derived tidal wave polarization relations. The dominance of the migrating tide follows from the phase relationship between zonal and meridional wind tides. By comparing the observed and derived vertical wind tides, we reveal qualitatively the altitude dependence of tidal wave dissipation.

  6. Impact of stratification and climatic perturbations to stratification on baroclinic and barotropic tides

    NASA Astrophysics Data System (ADS)

    Arbic, B. K.; Wetzel, A.; Cerovecki, I.; Hendershott, M.; Karsten, R. H.; Molinari, J.; Mueller, M.

    2012-12-01

    Recently there has been a great deal of interest in ocean mixing, primarily because ocean mixing is thought to control the strength of the oceanic meridional overturning circulation. An important source of ocean mixing is breaking internal waves, and an important energy source for oceanic internal waves is the astronomical tide. The ocean climate process team discussed in this session aims to develop parameterizations of internal-wave driven mixing which are suitable for the altered climates of our anticipated future as well as for the present climate. For this reason it is of interest to ask how climatic changes in the oceanic stratification have altered and will alter the ocean tides. By solving the Sturm-Liouville vertical mode problem with a present-day profile of oceanic temperature and salinity as well as the same profile altered by the observed temperature changes occuring over the last 135 years (Roemmich et al. 2012), we find that the square of the phase speed of the first mode baroclinic mode internal tide has changed by about 5-6% over that time frame. We alter the g' and layer depths of a two-layer numerical model of the global barotropic and baroclinic tides such that the phase speed changes by this amount. We will show the changes taking place in the baroclinic tide as well as in the barotropic tide. The barotropic tide changes because the phase speed of the barotropic tide depends on stratification (Gill 1982); this in turn affects the resonance of barotropic tides. The results of the numerical simulations are compared to a two-layer analytical model of tides in a forced-damped closed basin, which also predicts a sensitivity of both barotropic and baroclinic tides to stratification and to climatic perturbations to the stratification. Finally, the numerical results are compared to tide gauge observations of secular changes in tides occurring over the last century or so.

  7. Sea Level Rise and Land Subsidence Contributions to the Signals from the Tide Gauges of China

    NASA Astrophysics Data System (ADS)

    Parker, Albert

    2016-06-01

    The tide gauges measure the local oscillations of the sea level vs. the tide gauge instrument. The tide gauge instrument is generally subjected to the general subsidence or uplift of the nearby inland, plus some additional subsidence for land compaction and other localised phenomena. The paper proposes a non-linear model of the relative sea level oscillations including a long term trend for the absolute sea level rise, another term for the subsidence of the instrument, and finally a sinusoidal approximation for the cyclic oscillations of periodicities up to decades. This non-linear model is applied to the tide gauges of China. The paper shows that the limited information available for China does not permit to infer any proper trend for the relative rates of rise, as the tide gauge records are all short or incomplete and the vertical movement of the tide gauge instruments is unassessed. The only tide gauge record of sufficient length that may be assembled for China is obtained by combining the North Point and Quarry Bay tide gauges in Hong Kong (NPQB). This NQPB composite tide gauge record is shown to have similarities with the tide gauge records of Sydney, equally in the West pacific, and San Diego, in the east Pacific, oscillating about the longer term trend mostly determined by the local subsidence. As it is very well known that China generally suffers of land subsidence, and the tide gauge installations may suffer of additional subsidence vs. the inland, it may be concluded from the analysis of the other worldwide tide gauges that the sea levels of China are very likely rising about the same amount of the subsidence of the tide gauges, with the sea level acceleration component still negligible.

  8. Evaluate and characterize mechanisms controlling transport, fate and effects of Army smokes in the aerosol wind tunnel: Transport, transformations, fate, and terrestrial ecological effects of red phosphorus-butyl rubber and white phosphorus obscurant smokes: Final report

    SciTech Connect

    Van Voris, P.; Ligotke, M.W.; McFadden, K.M.; Li, S.M.W.; Thomas, B.L.; Cataldo, D.A.; Garland, T.R.; Fredrickson, J.K.; Bean, R.M.; Carlile, D.W.

    1987-10-01

    An evaluation of the terrestrial transport, transformations and ecological effects of phosphorus (red phosphorus-butyl rubber (RP/BR)) smoke obscurant was performed at Pacific Northwest Laboratory. A similar evaluation using white phosphorus (WP) smoke/obscurant is currently proceeding. The objective is to characterize the effects of smokes and obscurants on: (1) natural vegetation characteristic of US Army training sites in the United States; (2) physical and chemical properties of representative of soils of those sites; and (3) soil microbiological communities. The influence and interactions of smoke/obscurant concentration, relative humidity (25%, 60%, 90% and simulated rain) and wind speed of 0.22 to 4.45 m/s by smoke is assessed. Five plant species and four soils were exposed to both single and repeated doses of RP/BR smokes in the Pacific Northwest Laboratory ''P-3'' rated recirculating environmental wind tunnel. Detailed results for RP/BR and limited results for WP are presented. Toxicity symptoms for plants exposed for 2, 4, 6, and 8 hours to concentrations of RP/BR ranging from 200 mg/m/sup 3/ included leaf tip burn, leaf curl, leaf abscission and drop, floral abortion, chlorosis, neucrotic spotting, wilting, desiccation and dieback. Grass and bushbean were the most sensitive. The intensity and duration of these effects varied. Soils effects data suggest that there is an increase in the mobility of selected trace elements after exposure; however, this effect appears to be ameliorated with time. Soil microbial community effects show a reduction in the production of nitrate after soil is exposed to RP/BR smoke. Most of the plant, soil and soil microbial effects are transient in nature and are somewhat less intense resulting from repeated exposures; however, there is evidence that some of these environmental impacts may be persistent. 43 refs., 44 figs., 67 tabs.

  9. The effect of ocean tides on the earth's rotation as predicted by the results of an ocean tide model

    NASA Technical Reports Server (NTRS)

    Gross, Richard S.

    1993-01-01

    The published ocean tidal angular momentum results of Seiler (1991) are used to predict the effects of the most important semidiurnal, diurnal, and long period ocean tides on the earth's rotation. The separate, as well as combined, effects of ocean tidal currents and sea level height changes on the length-of-day, UT1, and polar motion are computed. The predicted polar motion results reported here account for the presence of the free core nutation and are given in terms of the motion of the celestial ephemeris pole so that they can be compared directly to the results of observations. Outside the retrograde diurnal tidal band, the summed effect of the semidiurnal and diurnal ocean tides studied here predict peak-to-peak polar motion amplitudes as large as 2 mas. Within the retrograde diurnal tidal band, the resonant enhancement caused by the free core nutation leads to predicted polar motion amplitudes as large as 9 mas.

  10. Cellular component of lavage fluid from broilers with normal versus aerosol-primed airways

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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)...

  11. Polar Motion Constraints on Models of the Fortnightly Tide

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    Estimates of the near-fortnightly Mf ocean tide from Topex/Poseidon satellite altimetry and from numerical solutions to the shallow water equations agree reasonably well, at least in their basin-scale features. For example, both show that the Pacific Ocean tide lags the Atlantic tide by roughly 30 degrees. There are hints of finer scale agreements in the elevation fields, but noise levels are high. In contrast, estimates of Mf currents are only weakly constrained by the TP data, because high-wavenumber Rossby waves (with intense currents) are associated with relatively small perturbations in surface elevation. As a result, a wide range of Mf current fields are consistent with both the TP data and the hydrodynamic equations within a priori plausible misfit bounds. We find that a useful constraint on the Mf currents is provided by independent estimates of the Earth's polar motion. At the Mf period polar motion shows a weak signal (both prograde and retrograde) which must be almost entirely caused by the ocean tide. We have estimated this signal from the SPACE2000 time series, after applying a broad-band correction for atmospheric angular momentum. Although the polar motion estimates have relatively large uncertainties, they are sufficiently precise to fix optimum data weights in a global ocean inverse model of Mf. These weights control the tradeoff between fitting a prior hydrodynamic model of Mf and fitting the relatively noisy T/P measurements of Mf. The predicted polar motion from the final inverse model agrees remarkably well with the Mf polar motion observations. The preferred model is also consistent with noise levels suggested by island gauges, and it is marginally consistent with differences observed by subsetting the altimetry (to the small extent that this is possible). In turn, this new model of the Mf ocean tide allows the ocean component to be removed from Mf estimates of length of day, thus yielding estimates of complex Love numbers less contaminated by

  12. Wind Forcing of the North Sea Pole Tide

    NASA Technical Reports Server (NTRS)

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

    1998-01-01

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

  13. Tide and tidal current observation in the Karimata Strait

    NASA Astrophysics Data System (ADS)

    Wei, Zexun; Fang, Guohong; Sulistiyo, Budi; Dwi Susanto, R.; Setiawan, Agus; Rameyo Adi, Tukul; Qiao, Fangli; Fan, Bin; Li, Shujiang

    2013-04-01

    It is believed that the water exchanges between the South China Sea and the Indonesian Seas are significant, and play an important role in the water mass formation and air-sea interactions of both the South China Sea and Indonesian Seas. It has also been found that the current in Sunda Strait has been obvious seasonal variation, which indicates the water exchange between West Indonesian Seas and India Ocean. In order to make quantitative evaluation of the magnitudes of the exchange, the First Institute of Oceanography (FIO), China, the Agency for Marine and Fisheries Research, Indonesia, and the Lamont-Doheries Earth Observatory, USA established a collaborative program, "The South-China Sea-Indonesian Seas Transport/Exchange (SITE) and Impacts on Seasonal Fish Migration" in 2006. And, they extend and expand the cooperation to Sunda Strait in 2008, the title of the collaborative program was changed to "The South China Sea - Indonesian Seas Transport/Exchange (SITE) and Dynamics of Sunda and Lombok Straits, and Their Impacts on Seasonal Fish Migration". Till now, 12 joint cruises have been conducted since December, 2007. Ten Trawl-Resistant Bottom Mounts (TRBM) have been deployed in the Karimata and Sunda Straits. The TRBMs are equipped with ADCPs and tide gauges for measuring current profiles and sea levels, respectively. The temperature-salinity profiles were measured with ship-board CTD during the cruises. Data obtained in Karimata Strait revealed that a significant water mass transport. This indicates that the Karimata Strait throughflow can greatly impacts the circulation of both the South China Sea and the Indonesian Seas. The data obtained at the 5 stations alone the two sections in the Karimata Strait were used to study the tide and tidal currents in the Karimata Strait. 2 TRBMs were deployed at Section A, as well as 3 at Section B, which lies at the southeast of Section A. Station B1 is in the Gaspar Strait between Bangka Island and Belitung Island, Stations

  14. 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

  15. Constraints on Energy Dissipation in the Earth's Body Tide From Satellite Tracking and Altimetry

    NASA Technical Reports Server (NTRS)

    Ray, Richard D.; Eanes, Richard J.; Lemoine, Frank G.

    1992-01-01

    The phase lag by which the earth's body tide follows the tidal potential is estimated for the principal lunar semidiurnal tide M(sub 2). The estimate results from combining recent tidal solutions from satellite tracking data and from Topex/Poseidon satellite altimeter data. Each data type is sensitive to the body-tide lag: gravitationally for the tracking data, geometrically for the altimetry. Allowance is made for the lunar atmospheric tide. For the tidal potential Love number kappa(sub 2) we obtain a lag epsilon of 0.20 deg +/- 0.05 deg, implying an effective body-tide Q of 280 and body-tide energy dissipation of 110 +/- 25 gigawatts.

  16. Lunar tidal acceleration obtained from satellite-derived ocean tide parameters

    NASA Technical Reports Server (NTRS)

    Goad, C. C.; Douglas, B. C.

    1978-01-01

    One hundred sets of mean elements of GEOS-3 computed at 2-day intervals yielded observation equations for the M sub 2 ocean tide from the long periodic variations of the inclination and node of the orbit. The 2nd degree Love number was given the value k sub 2 = 0.30 and the solid tide phase angle was taken to be zero. Combining obtained equations with results for the satellite 1967-92A gives the M sub 2 ocean tide parameter values. Under the same assumption of zero solid tide phase lag, the lunar tidal acceleration was found mostly due to the C sub 22 term in the expansion of the M sub 2 tide with additional small contributions from the 0 sub 1 and N sub 2 tides. Using Lambeck's (1975) estimates for the latter, the obtained acceleration in lunar longitudal in excellent agreement with the most recent determinations from ancient and modern astronomical data.

  17. Thermoluminescent aerosol analysis

    NASA Technical Reports Server (NTRS)

    Rogowski, R. S.; Long, E. R., Jr. (Inventor)

    1977-01-01

    A method for detecting and measuring trace amounts of aerosols when reacted with ozone in a gaseous environment was examined. A sample aerosol was exposed to a fixed ozone concentration for a fixed period of time, and a fluorescer was added to the exposed sample. The sample was heated in a 30 C/minute linear temperature profile to 200 C. The trace peak was measured and recorded as a function of the test aerosol and the recorded thermoluminescence trace peak of the fluorescer is specific to the aerosol being tested.

  18. 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.

  19. Statistical selection of tide gauges for Arctic sea-level reconstruction

    NASA Astrophysics Data System (ADS)

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

    2015-05-01

    In this paper, we seek an appropriate selection of tide gauges for Arctic Ocean sea-level reconstruction based on a combination of empirical criteria and statistical properties (leverages). Tide gauges provide the only in situ observations of sea level prior to the altimetry era. However, tide gauges are sparse, of questionable quality, and occasionally contradictory in their sea-level estimates. Therefore, it is essential to select the gauges very carefully. In this study, we have established a reconstruction based on empirical orthogonal functions (EOFs) of sea-level variations for the period 1950-2010 for the Arctic Ocean, constrained by tide gauge records, using the basic approach of Church et al. (2004). A major challenge is the sparsity of both satellite and tide gauge data beyond what can be covered with interpolation, necessitating a time-variable selection of tide gauges and the use of an ocean circulation model to provide gridded time series of sea level. As a surrogate for satellite altimetry, we have used the Drakkar ocean model to yield the EOFs. We initially evaluate the tide gauges through empirical criteria to reject obvious outlier gauges. Subsequently, we evaluate the "influence" of each Arctic tide gauge on the EOF-based reconstruction through the use of statistical leverage and use this as an indication in selecting appropriate tide gauges, in order to procedurally identify poor-quality data while still including as much data as possible. To accommodate sparse or contradictory tide gauge data, careful preprocessing and regularization of the reconstruction model are found to make a substantial difference to the quality of the reconstruction and the ability to select appropriate tide gauges for a reliable reconstruction. This is an especially important consideration for the Arctic, given the limited amount of data available. Thus, such a tide gauge selection study can be considered a precondition for further studies of Arctic sea

  20. Aerosol Measurements from Current and Future EUMETSAT Satellites

    NASA Astrophysics Data System (ADS)

    Lang, Ruediger; Munro, Rosemary; Kokhanovsky, Alexander; Grzegorski, Michael; Poli, Gabriele; Holdak, Andriy; Retscher, Christian; Marbach, Thierry

    2014-05-01

    EUMETSAT supports the operational monitoring and forecasting of atmospheric composition including various aerosol optical properties through specific products from its geostationary and polar-orbiting satellites. Meteosat imagery is used to characterise aerosols in the atmosphere, including volcanic ash and dust storms at high temporal resolution, while the GOME-2, AVHRR and IASI and instruments on Metop observe aerosol optical properties from the UV/vis to the infra-red spectral region from a polar morning orbit. The role of EUMETSAT in observing aerosol optical properties will expand further towards the 2020 timeframe when EUMETSAT also becomes the operator of the Copernicus Sentinel-3, 4 and 5 missions. This expanding role will be realised through additional atmospheric composition sounding instruments such as the UVN/Sentinel-4 on the Meteosat Third Generation (MTG) geostationary platforms and the 3MI, METimage, and Sentinel-5 instruments on the EPS Second Generation (EPS-SG) satellites. The synergistic use of imager, spectrometer and interferometer data will, with the availability of this new generation of instrumentation and with the need for measuring aerosol optical properties at short-time scales, high spatial resolution and over a broad spectra region, play and increasingly important role in the field of aerosol remote sensing. With its new Polar Multi-mission Aerosol optical properties (PMAp) product, providing aerosol and cloud optical depth information, as well as fine mode, dust and volcanic ash characterisation over ocean and in the future also over land, EUMETSAT has recently been implementing the first framework for such synergistic retrievals for the remote sensing of aerosol optical properties from GOME-2, AVHRR and IASI instruments on Metop. We will present an overview of the ongoing and the future developments at EUMETSAT concerning aerosol remote sensing from Metop as well as from the current MSG geostationary platforms and from the future

  1. Influence of DE3 tide on the equinoctial asymmetry of the zonal mean ionospheric electron density

    NASA Astrophysics Data System (ADS)

    Ren, Zhipeng; Wan, Weixing; Xiong, Jiangang; Liu, Libo

    2014-12-01

    Through respectively adding September DE3 tide and March DE3 tide at the low boundary of Global Coupled Ionosphere-Thermosphere-Electrodynamics Model, Institute of Geology and Geophysics, Chinese Academy of Sciences (GCITEM-IGGCAS), we simulate the influence of DE3 tide on the equinoctial asymmetry of the zonal mean ionospheric electron density. The influence of DE3 tide on the equinoctial asymmetry of the zonal mean electron density varies with latitude, altitude, and solar activity level. Compared with the density driven by the September DE3 tide, the March DE3 tide mainly decreases the lower ionospheric zonal mean electron density and mainly increases the electron density at higher ionosphere. In the low-latitude ionosphere, DE3 tide drives an equatorial ionization anomaly (EIA) structure at higher ionosphere in the relative difference of zonal mean electron density, which suggests that DE3 tide affects the longitudinal mean equatorial vertical E × B plasma drifts. Although the lower ionospheric equinoctial asymmetry driven by DE3 tide mainly decreases with the increase of solar activity, the asymmetry at higher ionosphere mainly increases with solar activity. However, EIA in equinoctial asymmetry mainly decreases with the increase of solar activity.

  2. Estimates of Internal Tide Energy Fluxes from Topex/Poseidon Altimetry: Central North Pacific

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

    Energy fluxes for first-mode M(sub 2) internal tides are deduced throughout the central North Pacific Ocean from Topex/Poseidon satellite altimeter data. Temporally coherent internal tide signals in the altimetry, combined with climatological hydrographic data, determine the tidal displacements, pressures, and currents at depth, which yield power transmission rates. For a variety of reasons the deduced rates should be considered lower bounds. Internal tides were found to emanate from several large bathymetric structures, especially the Hawaiian Ridge, where the integrated flux amounts to about six gigawatts. Internal tides are generated at the Aleutian Trench near 172 deg west and propagate southwards nearly 2000 km.

  3. 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.

  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. 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.

  6. The colors of biomass burning aerosols in the atmosphere.

    PubMed

    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

  7. The BlueTides simulation: first galaxies and reionization

    NASA Astrophysics Data System (ADS)

    Feng, Yu; Di-Matteo, Tiziana; Croft, Rupert A.; Bird, Simeon; Battaglia, Nicholas; Wilkins, Stephen

    2016-01-01

    We introduce the BlueTides simulation and report initial results for the luminosity functions of the first galaxies and active galactic nuclei (AGN), and their contribution to reionization. BlueTides was run on the BlueWaters cluster at National Center for Super-computing Applications from z = 99 to 8.0 and includes 2 × 70403 particles in a 400 h-1 Mpc per side box, making it the largest hydrodynamic simulation ever performed at high redshift. BlueTides includes a pressure-entropy formulation of smoothed particle hydrodynamics, gas cooling, star formation (including molecular hydrogen), black hole growth and models for stellar and AGN feedback processes, and a fluctuating ultraviolet background from a patchy reionization model. The predicted star formation rate density is a good match to current observational data at z ˜ 8-10. We find good agreement between observations and the predicted galaxy luminosity function in the currently observable range -18 ≤ MUV ≤ -22.5 with some dust extinction required to match the abundance of brighter objects. The predicted number counts for galaxies fainter than current observational limits are consistent with extrapolating the faint-end slope of the luminosity function with a power-law index α ˜ -1.8 at z ˜ 8 and redshift dependence of α ˜ (1 + z)-0.4. The AGN population has a luminosity function well fit by a power law with a slope α ˜ -2.4 that compares favourably with the deepest CANDELS GOODS fields. We investigate how these luminosity functions affect the progress of reionization, and find that a high Lyman α escape fraction (fesc ˜ 0.5) is required if galaxies dominate the ionizing photon budget during reionization. Smaller galaxy escape fractions imply a large contribution from faint AGN (down to MUV = -12) which results in a rapid reionization, disfavoured by current observations.

  8. Radiational tides at the southeastern coast of the Baltic Sea

    NASA Astrophysics Data System (ADS)

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

    2015-05-01

    The tides in the Baltic Sea are weak but unmistakably recognizable in sea-level spectra. Multiyear hourly tide gauge series enable us to examine specific tidal properties in detail and to identify some unexpected effects. Two nearby stations on the southeastern coast of the sea, namely Baltiysk, located in the strait connecting the Vistula Lagoon to the Baltic Sea, and Otkrytoe, on the coast of the Curonian Lagoon, are found to have very different character of tidal motions. Based on 13 years of simultaneous observations at these stations we constructed high-resolution spectra of sea level fluctuations that demonstrated that the tidal spectrum at Baltiysk is "classical" with sharp peaks corresponding to the major tidal constituents: M2, S2, N2, K1, O1, and P1. Unlike at Baltiysk, the main tidal peak at Otkrytoe is at the S1 frequency; the K1, P1, and S2 tidal harmonics also have significant peaks, while the other harmonics (including M2 and O1) are undistinguishable. Further analysis indicated that the tides at Baltiysk are generated by ordinary gravitational tidal forces, while at Otkrytoe they are induced by solar radiation, specifically by the breeze winds creating wind setups and setdowns in the Curonian Lagoon. Moreover, our findings demonstrate that the observed K1 and P1 peaks at Otkrytoe are related not to gravitational forces but to the seasonal modulation of the S1 radiational tidal constituent. The separate analysis of the "summer" and "winter" sea level spectra at Otkrytoe reveals prominent radiational tidal peaks (S1 and S2) in summer and the absence of these peaks in winter. The results of the analysis support the assumption that these motions are generated by the breeze winds associated with the sea/land temperature contrasts, which are substantial during the warm (ice-free) season but vague during the cold season when ice cover diminishes these contrasts.

  9. The Global S_1 Tide in Earth's Nutation

    NASA Astrophysics Data System (ADS)

    Schindelegger, Michael; Einšpigel, David; Salstein, David; Böhm, Johannes

    2016-05-01

    Diurnal S_1 tidal oscillations in the coupled atmosphere-ocean system induce small perturbations of Earth's prograde annual nutation, but matching geophysical model estimates of this Sun-synchronous rotation signal with the observed effect in geodetic Very Long Baseline Interferometry (VLBI) data has thus far been elusive. The present study assesses the problem from a geophysical model perspective, using four modern-day atmospheric assimilation systems and a consistently forced barotropic ocean model that dissipates its energy excess in the global abyssal ocean through a parameterized tidal conversion scheme. The use of contemporary meteorological data does, however, not guarantee accurate nutation estimates per se; two of the probed datasets produce atmosphere-ocean-driven S_1 terms that deviate by more than 30 μ as (microarcseconds) from the VLBI-observed harmonic of -16.2+i113.4 μ as. Partial deficiencies of these models in the diurnal band are also borne out by a validation of the air pressure tide against barometric in situ estimates as well as comparisons of simulated sea surface elevations with a global network of S_1 tide gauge determinations. Credence is lent to the global S_1 tide derived from the Modern-Era Retrospective Analysis for Research and Applications (MERRA) and the operational model of the European Centre for Medium-Range Weather Forecasts (ECMWF). When averaged over a temporal range of 2004 to 2013, their nutation contributions are estimated to be -8.0+i106.0 μ as (MERRA) and -9.4+i121.8 μ as (ECMWF operational), thus being virtually equivalent with the VLBI estimate. This remarkably close agreement will likely aid forthcoming nutation theories in their unambiguous a priori account of Earth's prograde annual celestial motion.

  10. Investigations of Tides from the Antiquity to Laplace

    NASA Astrophysics Data System (ADS)

    Deparis, Vincent; Legros, Hilaire; Souchay, Jean

    Tidal phenomena along the coasts were known since the prehistoric era, but a long journey of investigations through the centuries was necessary from the Greco-Roman Antiquity to the modern era to unravel in a quasi-definitive way many secrets of the ebb and flow. These investigations occupied the great scholars from Aristotle to Galileo, Newton, Euler, d'Alembert, Laplace, and the list could go on. We will review the historical steps which contributed to an increasing understanding of the tides.

  11. TOPEX/POSEIDON tides estimated using a global inverse model

    NASA Technical Reports Server (NTRS)

    Egbert, Gary D.; Bennett, Andrew F.; Foreman, Michael G. G.

    1994-01-01

    Altimetric data from the TOPEX/POSEIDON mission will be used for studies of global ocean circulation and marine geophysics. However, it is first necessary to remove the ocean tides, which are aliased in the raw data. The tides are constrained by the two distinct types of information: the hydrodynamic equations which the tidal fields of elevations and velocities must satisfy, and direct observational data from tide gauges and satellite altimetry. Here we develop and apply a generalized inverse method, which allows us to combine rationally all of this information into global tidal fields best fitting both the data and the dynamics, in a least squares sense. The resulting inverse solution is a sum of the direct solution to the astronomically forced Laplace tidal equations and a linear combination of the representers for the data functionals. The representer functions (one for each datum) are determined by the dynamical equations, and by our prior estimates of the statistics or errors in these equations. Our major task is a direct numerical calculation of these representers. This task is computationally intensive, but well suited to massively parallel processing. By calculating the representers we reduce the full (infinite dimensional) problem to a relatively low-dimensional problem at the outset, allowing full control over the conditioning and hence the stability of the inverse solution. With the representers calculated we can easily update our model as additional TOPEX/POSEIDON data become available. As an initial illustration we invert harmonic constants from a set of 80 open-ocean tide gauges. We then present a practical scheme for direct inversion of TOPEX/POSEIDON crossover data. We apply this method to 38 cycles of geophysical data records (GDR) data, computing preliminary global estimates of the four principal tidal constituents, M(sub 2), S(sub 2), K(sub 1) and O(sub 1). The inverse solution yields tidal fields which are simultaneously smoother, and in better

  12. Loading effect of a self-consistent equilibrium ocean pole tide on the gravimetric parameters of the gravity pole tides at superconducting gravimeter stations

    NASA Astrophysics Data System (ADS)

    Chen, Xiaodong; Ducarme, Bernard; Sun, Heping; Xu, Jianqiao

    2008-05-01

    The gravimetric parameters of the gravity pole tide are the amplitude factor δ, which is the ratio of gravity variations induced by polar motion for a real Earth to variations computed for a rigid one, and the phase difference κ between the observed and the rigid gravity pole tide. They can be estimated from the records of superconducting gravimeters (SGs). However, they are affected by the loading effect of the ocean pole tide. Recent results from TOPEX/Poseidon (TP) altimeter confirm that the ocean pole tide has a self-consistent equilibrium response. Accordingly, we calculate the gravity loading effects as well as their influence on the gravimetric parameters of gravity pole tide at all the 26 SG stations in the world on the assumption of a self-consistent equilibrium ocean pole tide model. The gravity loading effect is evaluated between 1 January 1997 and 31 December 2006. Numerical results show that the amplitude of the gravity loading effect reaches 10 -9 m s -2, which is larger than the accuracy (10 -10 m s -2) of a SG. The gravimetric factor δ is 1% larger at all SG stations. Then, the contribution of a self-consistent ocean pole tide to the pole tide gravimetric parameters cannot be ignored as it exceeds the current accuracy of the estimation of the pole tide gravity factors. For the nine stations studied in Ducarme et al. [Ducarme, B., Venedikov, A.P., Arnoso, J., et al., 2006. Global analysis of the GGP superconducting gravimeters network for the estimation of the pole tide gravimetric amplitude factor. J. Geodyn. 41, 334-344.], the mean of the modeled tidal factors δm = 1.1813 agrees very well with the result of a global analysis δCH = 1.1816 ± 0.0047 in that paper. On the other hand, the modeled phase difference κm varies from -0.273° to 0.351°. Comparing to the two main periods of the gravity pole tide, annual period and Chandler period, κm is too small to be considered. Therefore, The computed time difference κL induced by a self

  13. HOUSTON AEROSOL CHARACTERIZATION STUDY

    EPA Science Inventory

    An intensive field study of ambient aerosols was conducted in Houston between September 14 and October 14, 1978. Measurements at 12 sites were made using (1) two relocatable monitoring systems instrumented for aerosol and gaseous pollutants, (2) a network of high volume samplers ...

  14. Global Aerosol Observations

    Atmospheric Science Data Center

    2013-04-19

    ... atmosphere, directly influencing global climate and human health. Ground-based networks that accurately measure column aerosol amount and ... being used to improve Air Quality Models and for regional health studies. To assess the human-health impact of chronic aerosol exposure, ...

  15. 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.

  16. 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.

  17. Internal tides in the shallow water analysis and forecast system(SWAFS) in the Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Horton, C.; Clifford, M.; Schmitz, J.; Osterman, W.

    2003-04-01

    The Naval Oceanographic Office has been making daily forecasts of current speeds in the Mediterranean Sea, among other areas, using SWAFS since 1991. Our present Mediterranean model has a horizontal resolution of 1/35^o of latitude by 1/30^o of longitude with 47 sigma levels in the vertical. The normal configuration of our modelling system includes tides, and this is true for our Mediterranean Sea application. The relatively high resolution, both vertically and horizontally of the model grid in this basin, allows for the generation of internal tides from the imposed barotropic tide. As semidiurnal internal tides in the Mediterranean Sea have wavelengths of about 60-90 km, the approximately 3.3 km-resolution of the model grid is adequate. Furthermore, with 47 sigma levels, the thermocline is generally well-resolved. As internal tides are generated by the interaction of the barotropic tide with (steep) bathymetry, the modeling system also needs to use bathymetry with realistic bottom slopes. While the modeling system is built around a version of the Princeton Ocean Model having sigma coordinates in the vertical, horizontal pressure gradients are computed on level surfaces. The accuracy of this type of pressure gradient scheme is not limited by large bottom slopes, and the model bathymetry has not been smoothed to limit maximum bottom slopes. For these reasons, our modelling system for the Mediterranean Sea is potentially capable of generating internal tides with some fidelity. Considering the generally weak barotropic tides in the Mediterranean Sea, surprisingly strong internal tides are generated by the modelling system, especially near the Cretan Arc with its complex bathymetry. We will describe the internal tide field generated by the model, look at the major areas of internal tide generation, and describe the decay of the internal tides away from these sources. The internal tides are seen in the seasonal thermocline, and the corresponding seasonal changes in the

  18. Non-Migrating Tides, with Zonally Symmetric Component, Generated in the Mesosphere

    NASA Technical Reports Server (NTRS)

    Mayr, H. G.; Mengel, J. G.; Talaat, E. R.; Porter, H. S.; Hines, C. O.

    2003-01-01

    For comparison with measurements from the TIMED satellite and coordinated ground based observations, we discuss results from our Numerical Spectral Model (NSM) that incorporates the Doppler Spread Parameterization (Hines, 1997) for small-scale gravity waves (GWs). The NSM extends from the ground into the thermosphere and describes the major dynamical features of the atmosphere including the wave driven equatorial oscillations (QBO and SAO), and the seasonal variations of tides and planetary waves. With emphasis on the non-migrating tides, having periods of 24 and 12 hours, we discuss our modeling results that account for the classical migrating solar excitation sources only. As reported earlier, the NSM reproduces the observed seasonal variations and in particular the large equinoctial maxima in the amplitude of the migrating diurnal tide at altitudes around 90 km. Filtering of the tide by the zonal circulation and GW momentum deposition was identified as the cause. The GWs were also shown to produce a strong non-linear interaction between the diurnal and semi-diurnal tides. Confined largely to the mesosphere, the NSM produces through dynamical interactions a relatively large contribution of non-migrating tides. A striking feature is seen in the diurnal and semi-diurnal oscillations of the zonal mean (m = 0). Eastward propagating tides are also generated for zonal wave numbers m = 1 to 4. When the NSM is run without GWs, the amplitudes for the non-migrating tides, including m = 0, are generally small. Planetary wave interaction and non-linear coupling that involves the filtering of GWs and related height integration of dynamical features are discussed as possible mechanisms for generating these non-migrating tides in the NSM. As is the case for the solar migrating tides, the non-migrating tides reveal persistent seasonal variations. Under the influence of the QBO and SAO, interannual variations are produced.

  19. Cretaceous tide-dominated carbonate ramp: Comparison of reservoir hetergeneity in tide-versus wave-dominated carbonate ramp systems

    SciTech Connect

    Kerans, C.

    1995-08-01

    Cretaceous (upper Albian) carbonate ramp strata, Pecos River Canyon, Texas, provide a uniquely continuous exposure of a tide-dominated ramp reservoir analog. The continuous 100-km shelf-to-basin outcrop begins in inner ramp mud-rich facies that record both high-frequency (20-100 ky) and intermediate frequency (>200 ky) cyclicity. The ramp-crest is up to 40 km across depositional dip. Intermediate-scale cycles in the ramp crest include basal oyster and toucasid wackestones, chondrodontid-rudist packstones, rudist-skeletal grainstones, and caprinid biostromes. Ramp-crest grainstones are 4-23 m in thickness and extend more than 20 km in a shelf to basin direction. Rudist biostromes are 3-7 m in thickness and are up to several kilometers in dip continuity except in deeper outer ramp settings where 100-200 m wide mounds are more common. The ramp crest is dominated by grain-rich facies with moderate to high permeability. Toucasid wackestones and oyster marls are 1-5 m in thickness and extend tens of kilometers in a dip direction, representing potential fluid flow barriers. Wave-dominated ramp systems of the Permian of West Texas provide a contrast to the Cretaceous tide-dominated setting. Low-permeability high-frequency cycle base mudstones and high-permeability cycle-top grainstones are preserved in both inner ramp and ramp crest settings. Fluid-flow modeling of these Permian wave-dominated reservoir strata illustrates that the intercalation of thin high- and low-permeability layers result in crossflow trapping and thief zones controlling the position and amount of remaining oil saturation. The depositional homogeneity of the Cretaceous tide-dominated ramp indicates that diagenetic heterogeneities and gravitational effects are potentially dominant controls on reservoir performance for these strata.

  20. Radiative Effects of Aerosols

    NASA Technical Reports Server (NTRS)

    Valero, Francisco P. J.

    1996-01-01

    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 a pollution haze 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. The soot core increased the calculated extinction by about 10% in the most polluted drier layer relative to a pure sulfate aerosol but had significantly less effect at higher humidities. A 3 km descent through a boundary layer air mass dominated by pollutant aerosol with relative humidities (RH) 10-77% yielded a close agreement between the measured and calculated aerosol optical depths (550 nm) of 0.160 (+/- 0.07) and 0. 157 (+/- 0.034) respectively. During descent the aerosol mass scattering coefficient per unit sulfate mass varied from about 5 to 16 m(exp 2)/g and primarily dependent upon ambient RH. However, the total scattering coefficient per total fine mass was far less variable at about 4+/- 0.7 m(exp 2)/g. A subsequent descent through a Saharan dust layer located above the pollution aerosol layer revealed that both layers contributed similarly to aerosol optical depth. The scattering per unit mass of the coarse aged dust was estimated at 1.1 +/- 0.2 m(exp 2)/g. The large difference (50%) in measured and calculated optical depth for the dust layer exceeded measurements.

  1. Observations of internal tides in the Mozambique Channel

    NASA Astrophysics Data System (ADS)

    Manders, A. M. M.; Maas, L. R. M.; Gerkema, T.

    2004-12-01

    Internal waves in the Mozambique Channel were studied, in the narrowest passage between Mozambique and Madagascar. Seven current meter moorings were deployed for a year and a half. The observed baroclinic flow in the semidiurnal frequency band exhibited strong intermittency. Internal tides could be detected at nearly all times from differences between current meter records in amplitude and phase, varying in time. To study the long-term average of the internal tidal field, the overall energy in the semidiurnal bands was computed for each location. Internal tidal currents were everywhere strongest near the surface (around 4 cm/s at 250 m depth up to 12 cm/s near the pycnocline in the generation area), decreased to less than 3 cm/s at 600 m depth, and increased a little near the bottom. The results were compared with numerical results from a two-dimensional internal-tide generation model allowing a description of beam scattering at the pycnocline and repeated reflection. Model results and observations were in qualitative agreement.

  2. Evidence for infragravity wave-tide resonance in deep oceans.

    PubMed

    Sugioka, Hiroko; Fukao, Yoshio; Kanazawa, Toshihiko

    2010-01-01

    Ocean tides are the oscillatory motions of seawater forced by the gravitational attraction of the Moon and Sun with periods of a half to a day and wavelengths of the semi-Pacific to Pacific scale. Ocean infragravity (IG) waves are sea-surface gravity waves with periods of several minutes and wavelengths of several dozen kilometres. Here we report the first evidence of the resonance between these two ubiquitous phenomena, mutually very different in period and wavelength, in deep oceans. The evidence comes from long-term, large-scale observations with arrays of broadband ocean-bottom seismometers located at depths of more than 4,000 m in the Pacific Ocean. This observational evidence is substantiated by a theoretical argument that IG waves and the tide can resonantly couple and that such coupling occurs over unexpectedly wide areas of the Pacific Ocean. Through this resonant coupling, some of ocean tidal energy is transferred in deep oceans to IG wave energy. PMID:20981016

  3. Electrodynamic System of Earth in Moon and Solar Tides Investigation

    NASA Astrophysics Data System (ADS)

    Grunskaya, Lubov; Isakevich, Valiriy

    Since 2000 there has been working the united system of monitoring of electrical and geomagnetic fields of ELF range of the atmosphere boundary surface layer at the spaced apart stations: Vladimir State physical experimental ground; the station of RAS Institute of Sun and Earth physics at Lake Baikal; the station in Paratunka (Kamchatka); the station in Obninsk. There has been developed a programme-analytical system (PAS) to investigate signal structures in spectral and time series, caused by geophysical and astrophysical processes based on the method of eigen vectors. There has been developed a programme and analytical system to investigate the signal structure in the spectral and time series caused by geophysical processes. There has been estimated the amplitude and investigated the properties of the Earth atmosphere boundary layer electrical field components localized spectrally at the frequencies of the moon and solar tides. There has been exposed a method of determination of relative and absolute amplitudes of the main components of the eigen series. There has been investigated coherence of the spectral components at the frequencies of solar and moon tides. The work is carried out with supporting of RFFI № 14-07-97510, State Task to Universities on 2014-2016.

  4. Landslide movement in southwest Colorado triggered by atmospheric tides

    USGS Publications Warehouse

    Schulz, W.H.; Kean, J.W.; Wang, G.

    2009-01-01

    Landslides are among the most hazardous of geological processes, causing thousands of casualties and damage on the order of billions of dollars annually. The movement of most landslides occurs along a discrete shear surface, and is triggered by a reduction in the frictional strength of the surface. Infiltration of water into the landslide from rainfall and snowmelt and ground motion from earthquakes are generally implicated in lowering the frictional strength of this surface. However, solid-Earth and ocean tides have recently been shown to trigger shear sliding in other processes, such as earthquakes and glacial motion. Here we use observations and numerical modelling to show that a similar processatmospheric tidescan trigger movement in an ongoing landslide. The Slumgullion landslide, located in the SanJuan Mountains of Colorado, shows daily movement, primarily during diurnal low tides of the atmosphere. According to our model, the tidal changes in air pressure cause air and water in the sediment pores to flow vertically, altering the frictional stress of the shear surface; upward fluid flow during periods of atmospheric low pressure is most conducive to sliding. We suggest that tidally modulated changes in shear strength may also affect the stability of other landslides, and that the rapid pressure variations associated with some fast-moving storm systems could trigger a similar response. ?? 2009 Macmillan Publishers Limited. All rights reserved.

  5. DEM, tide and velocity over sulzberger ice shelf, West Antarctica

    USGS Publications Warehouse

    Baek, S.; Shum, C.K.; Lee, H.; Yi, Y.; Kwoun, Oh-Ig; Lu, Zhiming; Braun, Andreas

    2005-01-01

    Arctic and Antarctic ice sheets preserve more than 77% of the global fresh water and could raise global sea level by several meters if completely melted. Ocean tides near and under ice shelves shifts the grounding line position significantly and are one of current limitations to study glacier dynamics and mass balance. The Sulzberger ice shelf is an area of ice mass flux change in West Antarctica and has not yet been well studied. In this study, we use repeat-pass synthetic aperture radar (SAR) interferometry data from the ERS-1 and ERS-2 tandem missions for generation of a high-resolution (60-m) Digital Elevation Model (DEM) including tidal deformation detection and ice stream velocity of the Sulzberger Ice Shelf. Other satellite data such as laser altimeter measurements with fine foot-prints (70-m) from NASA's ICESat are used for validation and analyses. The resulting DEM has an accuracy of-0.57??5.88 m and is demonstrated to be useful for grounding line detection and ice mass balance studies. The deformation observed by InSAR is found to be primarily due to ocean tides and atmospheric pressure. The 2-D ice stream velocities computed agree qualitatively with previous methods on part of the Ice Shelf from passive microwave remote-sensing data (i.e., LANDSAT). ?? 2005 IEEE.

  6. Modeling the effect of tides and waves on benthic biofilms

    NASA Astrophysics Data System (ADS)

    Mariotti, G.; Fagherazzi, S.

    2012-12-01

    We propose a simple model for growth of benthic biofilm subject to variable hydrodynamic disturbances and with a biofilm-dependent erodibility (biostabilization). Model results show that, for disturbances with equal intensity, the biofilm is eroded or not depending on its current biomass, which is a function of the past evolution trajectory. Because of the finite time needed for a biofilm to develop, both the intensity and frequency of periodical disturbances, such as tidal currents, determine whether the biofilm can approach its equilibrium biomass. Spring-neap tidal modulation favors biofilm development, since the reduction of the current shear stress associated with neap tides allows biofilm growth, thus increasing biostabilization and the biofilm's likelihood to withstand the subsequent energetic spring tides. On the other hand, diurnal tidal modulations are negative for biofilm development, because the diel biofilm growth is almost negligible. Under stochastic disturbances associated with wind waves, there are two most-likely states for the biofilm biomass: either close to zero or close to the equilibrium value, depending on wave intensity. If biostabilization is reduced or eliminated, the probability of intermediate values for biofilm biomass becomes also significant. The role of biostabilization is hence to exacerbate the probability of the end-member states. Finally, because of the nonmonotonic relationship between water depth and wave induced bed stresses, only extremely shallow and deep areas favor biofilm persistence. If light attenuation with depth is considered, deep water becomes unsuitable for biofilm growth when water turbidity is high.

  7. Gravity and Tide Parameters Determined from Satellite and Spacecraft Orbits

    NASA Astrophysics Data System (ADS)

    Jacobson, Robert A.

    2015-05-01

    As part of our work on the development of the Jovian and Saturnian satellite ephemerides to support the Juno and Cassini missions, we determined a number of planetary system gravity parameters. This work did not take into account tidal forces. In fact, we saw no obvious observational evidence of tidal effects on the satellite or spacecraft orbits. However, Lainey et al. (2009 Nature 459, 957) and Lainey et. al (2012 Astrophys. J. 752, 14) have published investigations of tidal effects in the Jovian and Saturnian systems, respectively. Consequently, we have begun a re-examination of our ephemeris work that includes a model for tides raised on the planet by the satellites as well as tides raised on the satellites by the planet. In this paper we briefly review the observations used in our ephemeris production; they include astrometry from the late 1800s to 2014, mutual events, eclipses, occultatons, and data acquired by the Pioneer, Voyager, Ulysses, Cassini, Galileo, and New Horizons spacecraft. We summarize the gravity parameter values found from our original analyses. Next we discuss our tidal acceleration model and its impact on the gravity parameter determination. We conclude with preliminary results found when the reprocessing of the observations includes tidal forces acting on the satellites and spacecraft.

  8. Nonmigrating diurnal tides in the equatorial middle atmosphere

    NASA Technical Reports Server (NTRS)

    Lieberman, Ruth S.

    1991-01-01

    Data from the Nimbus-7 Limb Infrared Monitor of the Stratosphere (LIMS) are used to extend the analysis of diurnal tides in the middle atmosphere to include the zonally symmetric and eastward propagating components. These modes show vertical and meridional structures that are generally consistent with the predictions of linear tidal theory. The zonal and meridional wind fields are calculated from the tidal temperatures. Diurnal perturbations in LIMS temperature and derived winds agree well with equinoctial model calculations. Comparisons with day-night differences of radiosonde temperature and rocket winds show qualitative agreement in vertical structure and amplitude. The zonally symmetric and eastward migrating tidal components show a higher degree of temporal variability than the sun-synchronous component. These modes at times contribute substantially to the diurnal signal in wind and temperature, with combined amplitudes equal to or in excess of the amplitude of the main migrating diurnal tide. The observed vertical phase variations suggest that their forcing may originate below the stratosphere.

  9. Tides as drivers of plates and criticism of mantle convection

    NASA Astrophysics Data System (ADS)

    Ostrihansky, Lubor

    2015-04-01

    Forces moving plates are of two kinds: Force moving plates to the north and force moving plates to the west. They are both, by their origin, related to tidal forces but they act in quite different way. The northward force acts by its center in meridian, the westward force acts in direction of geographic parallels. Tidal forces of semidiurnal and diurnal periods cannot move plates because triggering of earthquakes by the stress of these amplitudes gives statistically insignificant results confirmed by many reports for more than 100 years. However the tidal forces acting on 10 km Earth's rotation bulges and the periodic Earth's deformations resulting in Earth's rotation variations give strong forces energetically equivalent to energy of large earthquakes. Oceanic lithosphere older than 180 M.Y. drops down to the mantle by gravity or is liquidated being overridden beneath continent. At that movement the released space facilitates the plate movement by tides. Hotspots firmly anchored in mantle show by tracks an exact movement of plates. Mantle convection is disregarded because it contradicts to existence of mid-ocean ridges triple junctions. Not Polfluchtkraft but Äquatorkraft force the tides create, which can move the large continent (for example Gondwana) far from equator as far as the pole, where after decay the Antarctica remains being out of tidal forces actions.

  10. Pacific Northwest tide channel utilization by fish as an ecosystem service

    EPA Science Inventory

    Background/Question/Methods: Saltwater marsh tide channels are considered to be important in the ecology of estuarine fish serving both as a refuge and as a provider of enhanced food resources. However, this presumed function of tide channels in Pacific Northwest estuaries has ...

  11. Pacific Northwest tide channel utilization by fish as an ecosystem service - August 2013

    EPA Science Inventory

    Background/Question/Methods: Saltwater marsh tide channels are considered to be important in the ecology of estuarine fish serving both as a refuge and as a provider of enhanced food resources. However, this presumed function of tide channels in Pacific Northwest estuaries has r...

  12. Minutes of TOPEX/POSEIDON Science Working Team Meeting and Ocean Tides Workshop

    NASA Technical Reports Server (NTRS)

    Fu, Lee-Lueng (Editor)

    1995-01-01

    This third TOPEX/POSEIDON Science Working Team meeting was held on December 4, 1994 to review progress in defining ocean tide models, precision Earth orbits, and various science algorithms. A related workshop on ocean tides convened to select the best models to be used by scientists in the Geophysical Data Records.

  13. Tidal asymmetry in a tidal creek with mixed mainly semidiurnal tide, Bushehr Port, Persian Gulf

    NASA Astrophysics Data System (ADS)

    Hosseini, Seyed Taleb; Chegini, Vahid; Sadrinasab, Masoud; Siadatmousavi, Seyed Mostafa; Yari, Sadegh

    2016-03-01

    This study investigated the tidal asymmetry imposed by both the interaction of principal tides and the higher harmonics generated by distortions within a tidal creek network with mixed mainly semidiurnal tide in the Bushehr Port, Persian Gulf. Since velocity and water-level imposed by principal triad tides K1-O1-M2 are in quadrature, duration asymmetries during a tidal period in this short, shallow inverse estuary should be manifest as skewed velocities. The principal tides produce periodic asymmetries including a strong ebb-dominance and a weak flood-dominance condition during spring and neap tides respectively. The higher harmonics induced by nonlinearities engender a flood-dominance condition where the convergence effects are higher than frictional effects, and an ebbdominance condition where intertidal storage are extended. Since the triad K1-O1-M2 driven asymmetry is not overcome by higher harmonics close to the mouth, the periodic asymmetry dominates within the creek in which higher harmonics reinforce the weak flood-dominance (strong ebb-dominance) condition in the convergent channel (divergent area). Also, the maximum flood and the maximum ebb from all harmonic constituents occurred close to high water slack time during both spring and neap tides in this short creek. Since occational wetting of intertidal areas happened close to the high water (HW) time during spring tide, the water level flooded slowly close to the HW time of the spring tide.

  14. Pressure tide gauge records from the Atlantic shelf off Tierra del Fuego, southernmost South America

    NASA Astrophysics Data System (ADS)

    Richter, Andreas; Mendoza, Luciano; Perdomo, Raúl; Hormaechea, José Luis; Savcenko, Roman; Bosch, Wolfgang; Dietrich, Reinhard

    2012-07-01

    Based on pressure tide gauge observations at three sites off the Atlantic coast of Tierra del Fuego main island, time series spanning one to seven months of bottom pressure and sea-level variations are derived and analysed to reveal the major driving mechanisms. Ocean tides account for 99.5% of the total energy of the sea-level variations. The amplitudes and phases of a comprehensive set of tidal constituents resulting from a harmonic tidal analysis are presented. Exceptionally large shallow-water tides are identified. The second largest contribution is due to the local inverse barometer model accounting for up to 65% of the variance of the tide residual sea-level variations. Close to the shore a significant topographic modulation of the sea-level variations is revealed. The in situ observations are compared with six recent global ocean tide models, official tide tables, and sea-surface heights derived from satellite altimetry data. The amplitudes and phases predicted by the ocean tide models for the semidiurnal and diurnal constituents agree with those derived from our tide gauge records on average within 2 cm and 5°, respectively. In the time domain the tidal signal represented by the models deviates typically by a few decimetres from that extracted from our records. Absolute altimeter biases were determined for the Jason-2, Jason-1 extended mission, and Envisat satellite altimeters. Relative sea-level variations are represented by the altimetry data with an accuracy of the order of 5 cm.

  15. Merging the OSIRIS and SAGE II stratospheric aerosol records

    NASA Astrophysics Data System (ADS)

    Rieger, L. A.; Bourassa, A. E.; Degenstein, D. A.

    2015-09-01

    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 are retrieved. The Stratospheric Aerosol and Gas Experiment (SAGE) II was launched in 1984 and provided measurements of stratospheric aerosol extinction until mid-2005. This provides approximately 4 years of mission overlap which has allowed us to consistently extend the SAGE II version 7.00 record to the present using OSIRIS aerosol extinction retrievals. In this work we first compare coincident aerosol extinction observations during the overlap period by interpolating the SAGE II 525nm and 1020nm channels to the OSIRIS extinction wavelength of 750nm. In the tropics to midlatitudes mean differences are typically less than 10%, although larger biases are seen at higher latitudes and at altitudes outside the main aerosol layer. OSIRIS aerosol extinction retrievals at 750nm are used to create a monthly time series zonally averaged in 5°bins and qualitatively compared to SAGE II 525nm observations averaged in the same way. The OSIRIS time series is then translated to 525nm with an Ângström exponent relation and bias corrected. For most locations, this provides agreement during the overlap time period to better than 15%. Uncertainty in the resulting OSIRIS time series is estimated through a series of simulation studies over the range of aerosol particle size distributions observed by in situ balloon instruments and is found to be approximately 20% for background and moderately volcanic aerosol loading conditions for the majority of OSIRIS measurement conditions.

  16. Optical Properties of Black and Brown Carbon Aerosols from Laboratory Combustion of Wildland Fuels

    NASA Astrophysics Data System (ADS)

    Beres, N. D.; Molzan, J.

    2015-12-01

    Aerosol light absorption in the solar spectral region (300 nm - 2300 nm) of the atmosphere is key for the direct aerosol radiative forcing, which is determined by aerosol single scattering albedo (SSA), asymmetry parameter, and by the albedo of the underlying surface. SSA is of key importance for the sign and quantity of aerosol direct radiative forcing; that is, does the aerosol make the earth look darker (heating) or whiter (cooling)? In addition, these optical properties are needed for satellite retrievals of aerosol optical depth and properties. During wildland fires, aerosol optical absorption is largely determined by black carbon (BC) and brown carbon (BrC) emissions. BC is strongly absorbing throughout the solar spectrum, while BrC absorption strongly increases toward shorter wavelength and can be neglected in the red and infrared. Optical properties of BrC emitted from wildland fires are poorly understood and need to be studied as function of fuel type and moisture content and combustion conditions. While much more is known about BC optical properties, knowledge for the ultraviolet (UV) spectral region is still lacking and critically needed for satellite remote sensing (e.g., TOMS, OMI) and for modeling of tropospheric photochemistry. Here, a project to better characterize biomass burning aerosol optical properties is described. It utilizes a laboratory biomass combustion chamber to generate aerosols through combustion of different wildland fuels of global and regional importance. Combustion aerosol optics is characterized with an integrating nephelometer to measure aerosol light scattering and a photoacoustic instrument to measure aerosol light absorption. These measurements will yield optical properties that are needed to improve qualitative and quantitative understanding of aerosol radiative forcing and satellite retrievals for absorbing carbonaceous aerosols from combustion of wildland fuels.

  17. Sugars in Antarctic aerosol

    NASA Astrophysics Data System (ADS)

    Barbaro, Elena; Kirchgeorg, Torben; Zangrando, Roberta; Vecchiato, Marco; Piazza, Rossano; Barbante, Carlo; Gambaro, Andrea

    2015-10-01

    The processes and transformations occurring in the Antarctic aerosol during atmospheric transport were described using selected sugars as source tracers. Monosaccharides (arabinose, fructose, galactose, glucose, mannose, ribose, xylose), disaccharides (sucrose, lactose, maltose, lactulose), alcohol-sugars (erythritol, mannitol, ribitol, sorbitol, xylitol, maltitol, galactitol) and anhydrosugars (levoglucosan, mannosan and galactosan) were measured in the Antarctic aerosol collected during four different sampling campaigns. For quantification, a sensitive high-pressure anion exchange chromatography was coupled with a single quadrupole mass spectrometer. The method was validated, showing good accuracy and low method quantification limits. This study describes the first determination of sugars in the Antarctic aerosol. The total mean concentration of sugars in the aerosol collected at the "Mario Zucchelli" coastal station was 140 pg m-3; as for the aerosol collected over the Antarctic plateau during two consecutive sampling campaigns, the concentration amounted to 440 and 438 pg m-3. The study of particle-size distribution allowed us to identify the natural emission from spores or from sea-spray as the main sources of sugars in the coastal area. The enrichment of sugars in the fine fraction of the aerosol collected on the Antarctic plateau is due to the degradation of particles during long-range atmospheric transport. The composition of sugars in the coarse fraction was also investigated in the aerosol collected during the oceanographic cruise.

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

    NASA Technical Reports Server (NTRS)

    Ray, Richard D.

    2009-01-01

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

  19. Global ocean tide models on the eve of Topex/Poseidon

    SciTech Connect

    Ray, R.D. )

    1993-03-01

    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 M[sub 2] 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. The subject, however, is in a state of flux, and one may expect rapid advancement over the next several years.

  20. M2, S2, K1 models of the global ocean tide

    NASA Technical Reports Server (NTRS)

    Parke, M. E.; Hendershott, M. C.

    1979-01-01

    Ocean tidal signals appear in many geophysical measurements. Geophysicists need realistic tidal models to aid in interpretation of their data. Because of the closeness to resonance of dissipationless ocean tides, it is difficult for numerical models to correctly represent the actual open ocean tide. As an approximate solution to this problem, test functions derived by solving Laplace's Tidal Equations with ocean loading and self gravitation are used as a basis for least squares dynamic interpolation of coastal and island tidal data for the constituents M2, S2, and Kl. The resulting representations of the global tide are stable over at least a ?5% variation in the mean depth of the model basin, and they conserve mass. Maps of the geocentric tide, the induced free space potential, the induced vertical component of the solid earth tide, and the induced vertical component of the gravitational field for each contituent are presented.

  1. Comparison of tide model outputs for the northern region of the Antarctic Peninsula using satellite altimeters and tide gauge data

    NASA Astrophysics Data System (ADS)

    Oreiro, Fernando A.; D'Onofrio, Enrique; Grismeyer, Walter; Fiore, Mónica; Saraceno, Martín

    2014-03-01

    This study compares the common harmonic constants of the O1, K1, P1, Q1, M2, S2, N2, and K2 tidal constituents from eight global and four regional tide models with harmonic constants from satellite altimeter and tide gauge data for the northern region of the Antarctic Peninsula (58°S-66°S, 53°W-66°W). To obtain a more representative comparison, the study area was divided into three zones with different physical characteristics but similar maximum tidal amplitude variations: Zone I (north of 62°S), Zone II (south of 62°S and west of the Antarctic Peninsula), and Zone III (between 62°S and 64.3°S, and east of 58.5°W). Root sum square (RSS) values are less than or equal to 3.0, 4.2, and 8.4 cm for zones I, II, and III, respectively. No single model shows superior performance in all zones. Because there are insufficient satellite altimetry observations in the vicinity of Matienzo Base (64.9761°S, 60.0683°W), this station was analyzed separately and presents the greatest values of both root mean square misfit and RSS. The maximum, minimum, and average amplitude values of the constituents that follow in importance after the eight common tidal constituents, and which have amplitudes greater than 1 cm, are also analyzed.

  2. Interpretation of Aerosol Optical and Morphological Properties during the Carbonaceous Aerosols and Radiative Effects Study in Sacramento, June 2010

    NASA Astrophysics Data System (ADS)

    Gorkowski, K.; Mazzoleni, C.; China, S.; Sharma, N.; Flowers, B. A.; Dubey, M. K.; Gyawali, M. S.; Arnott, W. P.; Zaveri, R. A.

    2010-12-01

    The Sacramento Carbonaceous Aerosols and Radiative Effects Study (CARES) utilized two ground sites T0 and T1 along with an aircraft platform to characterize carbonaceous aerosol chemical and physical properties and their evolution. The T0 site was chosen within the Sacramento metropolitan area for measuring primary and secondary aerosols generated in the city. The T1 site was chosen East of Sacramento on the Sierra foothill to study the evolution and processing of the Sacramento aerosol plume and to assess the characteristics of the background air. To reach T1, the Sacramento aerosols traveled often over the Blodgett Forest resulting in significant aging due coagulation, condensation, and photochemical processes. The ground sites were chosen for this unique and reoccurring transport pattern of the aerosols. The campaign took place in June 2010. Six Integrated Photoacoustic/Nephelometer Spectrometers (IPNSs) were installed at the sites to simultaneously record aerosol light scattering and absorption data. The optical properties of the aerosols were measured at 355nm (ultraviolet), 375nm (ultraviolet), 405nm (blue), 532nm (green), and 781nm (red). In conjugation with the IPNSs, aerosol filters for electron microscopy analysis were collected at each site; these were examined using a field emission scanning electron microscope to study the aerosol morphology. The origins of the air masses did vary daily, but a few general trends emerged. The processing of the IPNS data with a wavelet denoising technique greatly enhanced the signal to noise ratio of the measurements enabling a better understanding of the aerosol optical properties for various airmasses with different characteristics. Typically signals at both sites were lower than expected, however the processed signals from T0 clearly showed a daily rise and dilution of the Sacramento plume. Using the processed signals from both sites the transportation of the Sacramento plume was detectable. The IPNS data were

  3. Analysis of the most recent data of Cascais Tide Gauge

    NASA Astrophysics Data System (ADS)

    Antunes, Carlos; Taborda, Rui; Mendes, Virgílio B.

    2010-05-01

    In order to meet international standards and to integrate sea level changes and tsunami monitoring networks, Cascais tide gauge, one of the oldest in the world, has been upgraded in 2003 with new acoustic equipment with digital data acquisition, temperature and air-pressure sensors, and internet connection for real time data. The new tide gauge is located very close to the old analogical gauge, which is still working. Datum links between both gauges and the permanent GPS station of Cascais were made and height differences between gauges and the GPS station have been monitored to verify site stability and to estimate the absolute vertical velocity of the site, and therefore, the absolute sea level changes. Tide gauge data from 2000 to 2009 has been analyzed and relative and absolute sea level rise rates have been estimated. The estimation of sea level rise rate with the short baseline of 10 years is made with the daily mean sea level data corrected from the inverse barometric effect. The relative sea level trend is obtained from a 60-day moving average run over the corrected daily mean sea level. The estimated rate has shown greater stability in contrast to the analysis of daily mean sea level raw data, which shows greater variability and uncertainty. Our results show a sea level rise rate of 2.6 mm/year (± 0.3 mm/year), higher than previous rates (2.1 mm/year for 1990 decade and 1.6 mm/year from 1920 to 2000), which is compatible with a sea level rise acceleration scenario. From the analysis of Cascais GPS data, for the period 1990.0 to 2010.0 we obtain an uplift rate of 0.3 mm/year leading to an absolute sea level rise of 2.9 mm/year for Cascais, under the assumption, as predicted by the ICE-5G model, that Cascais has no vertical displacement caused by the post-glacial isostatic adjustment.

  4. Comparison of aerosol size distribution in coastal and oceanic environments

    NASA Astrophysics Data System (ADS)

    Kusmierczyk-Michulec, Jolanta; van Eijk, Alexander M.

    2006-08-01

    The results of applying the empirical orthogonal functions (EOF) method to decomposition and approximation of aerosol size distributions are presented. A comparison was made for two aerosol data sets, representing coastal and oceanic environments. The first data set includes measurements collected at the Irish Atlantic coast in 1994 and 1995, the second one data collected during the Rough Evaporation Duct (RED) experiment that took place off Oahu, Hawaii in 2001. The main finding is that aerosol size distributions can be represented by a superposition of the mean size distribution and the first eigenvector multiplied by an amplitude function. For the two aerosol data sets the mean size distribution is very similar in the range of small particles sizes (radius < 1μm) but the main difference appears for larger aerosols (radius > 1μm). It is also reflected by the spectral shape of the eigenvector. The differences can be related to the type of aerosols present at both locations, and the amplitude function can be associated to meteorological conditions. The amplitude function also indicates the episodes with the maximum/minimum continental influence. The results of this analysis will be used in upgrades of the ANAM model.

  5. Red blood cell production

    MedlinePlus

    ... cells are an important element of blood. Their job is to transport oxygen to the body’s tissues in exchange for carbon dioxide, which is carried to and eliminated by the lungs. Red blood cells are formed in the red bone marrow of bones. Stem cells in the red bone marrow called hemocytoblasts ...

  6. RED-LETTER DAYS

    EPA Science Inventory

    The word "red-letter" is an adjective meaning "of special significance." It's origin is from the practice of marking Christian holy days in red letters on calendars. The "red-letter days" to which I refer occurred while I was a graduate student of ...

  7. International Federation of Red Cross and Red Crescent Societies

    MedlinePlus

    ... dignity and resilience Geneva, 14 September 2016 – The International Federation of Red Cross and Red Crescent Societies... ... News Contact us Sitemap Go to top The International Federation of Red Cross and Red Crescent Societies ( ...

  8. Atmospheric Tides Simulated by WACCM-1 and CMIP3 / IPCC Climate Models

    NASA Astrophysics Data System (ADS)

    Covey, C. C.; Dai, A.; Lindzen, R. S.

    2008-12-01

    Atmospheric tides driven by solar heating are readily detectable at Earth's surface as variations in air pressure. Above the lower stratosphere the tides attain large amplitudes and can be a significant part of atmospheric motion. Output from the general circulation model WACCM, the Whole-Atmosphere Community Climate Model, contains tidal oscillations in its middle and upper atmosphere, but it has not previously been examined for the surface signature of the tides. We have done so both for WACCM Version 1 and for the climate models contributing to the latest assessment report of the Intergovernmental Panel on Climate Change (taken from the Coupled Model Intercomparison Project phase 3 [CMIP3] archive; see URL below). Surface pressure tides in WACCM-1's output occur mainly in the tropics and are dominated by the semidiurnal component, as observed. Quantitatively, however, WACCM-1 overestimates the diurnal tide amplitude by up to a factor of two over tropical land while underestimating it by about one-third globally. Similar though less egregious errors occur in WACCM-1's semidiurnal tide. Although the observed pressure field is contaminated by sampling errors, it is clear that WACCM-1 misses robust real-world features such as the large diurnal tides over mid-latitude high terrain and the non-migrating component of both diurnal and semidiurnal tides. We have not yet examined output from the most recent version of the model (WACCM-3), however. Climate modelers generally do not have atmospheric tides or the middle atmosphere in mind during the model development process, and conventional wisdom holds that the dominant semidiurnal surface-pressure tide is mainly forced by ozone heating in the middle atmosphere. One might therefore expect that climate models with tops below the ozone heating peak (at roughly 50 km altitude) or with poor resolution in the middle atmosphere would produce surface pressure tides that are weaker than observed and perhaps dominated by the

  9. FINITE ELEMENT MODEL FOR TIDES AND CURRENTS WITH FIELD APPLICATIONS.

    USGS Publications Warehouse

    Walters, Roy A.

    1988-01-01

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

  10. Non-Stationary Internal Tides Observed with Satellite Altimetry

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

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

  11. Lunar Fluid Core and Solid-Body Tides

    NASA Technical Reports Server (NTRS)

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

    2005-01-01

    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) [2-5] 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 has been improving [3,5] and now seems significant. This strengthens the case for a fluid lunar core.

  12. Exuberant interference: rainbows, tides, edges, (de)coherence...

    PubMed

    Berry, M V

    2002-05-15

    Young's pioneering studies of interference have led to fundamental developments in wave physics. Supernumerary rainbows were the first example of diffraction associated with caustics. Cotidal lines (connecting places where the tide is high at a given time) were the first example of wavefronts in the modern sense (pattern of phase contours (arg psi(1) + psi(2)) of the superposition of waves psi(1) and psi(2), rather than the superposed patterns of the separate phases arg psi(1) and arg psi(2)), and led to the discovery of phase singularities. Edge-diffracted waves extend the range of asymptotic methods applied to waves and continue to find diverse and unexpected applications. Young's understanding of the conditions for observing interference are now part of decoherence theory, which explains, for example, the emergence of the classical world from the quantum world. PMID:12804291

  13. Volcanic Aerosol Radiative Properties

    NASA Technical Reports Server (NTRS)

    Lacis, Andrew

    2015-01-01

    Large sporadic volcanic eruptions inject large amounts of sulfur bearing gases into the stratosphere which then get photochemically converted to sulfuric acid aerosol droplets that exert a radiative cooling effect on the global climate system lasting for several years.

  14. Palaeoclimate: Aerosols and rainfall

    NASA Astrophysics Data System (ADS)

    Partin, Jud

    2015-03-01

    Instrumental records have hinted that aerosol emissions may be shifting rainfall over Central America southwards. A 450-year-long precipitation reconstruction indicates that this shift began shortly after the Industrial Revolution.

  15. Aerosol lenses propagation model.

    PubMed

    Tremblay, Grégoire; Roy, Gilles

    2011-09-01

    We propose a model based on the properties of cascading lenses modulation transfer function (MTF) to reproduce the irradiance of a screen illuminated through a dense aerosol cloud. In this model, the aerosol cloud is broken into multiple thin layers considered as individual lenses. The screen irradiance generated by these individual layers is equivalent to the point-spread function (PSF) of each aerosol lens. Taking the Fourier transform of the PSF as a MTF, we cascade the lenses MTF to find the cloud MTF. The screen irradiance is found with the Fourier transform of this MTF. We show the derivation of the model and we compare the results with the Undique Monte Carlo simulator for four aerosols at three optical depths. The model is in agreement with the Monte Carlo for all the cases tested. PMID:21886230

  16. Bottom Pressure Variability in the Red Sea

    NASA Astrophysics Data System (ADS)

    Limeburner, R.; Abualnaja, Y.; Beardsley, R.

    2012-04-01

    We deployed an array of three bottom pressure/temperature/conductivity (PTC) instruments at Jeddah, Thuwal and Rabigh along the Saudi Arabian coast of the eastern Red Sea for a period of 3 years. This PTC array accurately measured the regional tidal variability of the bottom pressure field and characterized the low frequency along-shore pressure, temperature and salinity gradients and their variability. Surface sea level/height was calculated from the bottom pressure measurements using the hydrostatic equation. On time scales of order 1 day the most energetic component of sea level variability was the semidiurnal and diurnal tides dominated by the M2, N2, K1 and O1 tidal constituents. On time scales of order 10 days the sea level variability was wind driven with setup and set down up to 40 cm due to the local wind stress. On yearly time scales the sea level varied approximately 50 cm and was highest in winter (January-February) and lowest in summer (July-August). Barometric pressure also had an annual cycle of approximately 10 mb and was highest in January thus attenuating the amplitude of the annual sea level variability. Higher sea level in winter months may be due to a convergence in the large-scale Red Sea wind stress. The amplitude of the principal tidal and subtidal sea level variability was coherent at the three sites, but the direction of phase propagation could not be resolved with confidence.

  17. Scattering of Internal Tides by Irregular Bathymetry of Large Extent

    NASA Astrophysics Data System (ADS)

    Mei, C.

    2014-12-01

    We present an analytic theory of scattering of tide-generated internal gravity waves in a continuously stratified ocean with a randomly rough seabed. Based on the linearized approximation, the idealized case of constant mean sea depth and Brunt-Vaisala frequency is considered. The depth fluctuation is assumed to be a stationary random function of space characterized by small amplitude and correlation length comparable to the typical wavelength. For both one- and two-dimensional topography the effects of scattering on wave phase over long distances are derived explicitly by the method of multiple scales. For one-dimensional topography, numerical results are compared with Buhler-& Holmes-Cerfon(2011) computed by the method of characteristics. For two-dimensional topography, new results are presented for both statistically isotropic and anisotropic cases. In thi talk we shall apply the perturbation technique of multiple scales to treat analytically the random scattering of internal tides by gently sloped bathymetric irregularities.The basic assumptions are: incompressible fluid, infinitestimal wave amplitudes, constant Brunt-Vaisala frequency, and constant mean depth. In addition, the depth disorder is assumed to be a stationary random function of space with zero mean and small root-mean-square amplitude. The correlation length can be comparable in order of magnitude as the dominant wavelength. Both one- and two-dimensional disorder will be considered. Physical effects of random scattering on the mean wave phase i.e., spatial attenuation and wavenumber shift will be calculated and discussed for one mode of incident wave. For two dimensional topographies, statistically isotropic and anisotropic examples will be presented.

  18. Ionospheric signatures of non-migrating tides and stratospheric warming

    NASA Astrophysics Data System (ADS)

    Lühr, Hermann; Stolle, Claudia; Häusler, Kathrin

    2010-05-01

    Observational data bases from recent years provided more and more evidence that climate and weather phenomena influence the dynamics of the high atmosphere. In the first part of this presentation we will address the dynamical interaction caused by non-migrating tides. Several of these tidal modes are generated in the lower atmosphere and are believed to propagate all the way up to the exosphere. Quantities that reflect the characteristics of the tides very well, are thermospheric temperature and wind. The dynamics of the neutrals is partly transferred to charged particles in the ionospheric E-layer. For that reason tidal signals are also present in the ionospheric E and F region. We show, as examples, the effect on the equatorial electrojet (EEJ), vertical plasma drift and F region electron density. Since the coupling conditions and strength between neutral and charged particles vary over the course of a day (a year, a solar cycle), the recovery of the complete ionospheric tidal signals is complex. We will present the amplitude and annual variation for the most prominent tidal components. A very recent topic of vertical coupling is the influence of sudden stratospheric warming (SSW) on the ionospheric electrodynamics. SSW has been shown to modify among others the diurnal variation of the vertical plasma drift and the electric field at equatorial latitudes. We will present global observations of the EEJ and its response to SSW events in 2002/2003. A typical feature is an enhancement of the EEJ intensity in the pre-noon hours and a reduction in the afternoon. Possible mechanisms causing these modifications will be discussed.

  19. The intertidal hydraulics of tide-dominated reef platforms

    NASA Astrophysics Data System (ADS)

    Lowe, Ryan J.; Leon, Arturo S.; Symonds, Graham; Falter, James L.; Gruber, Renee

    2015-07-01

    A 2 week field experiment investigated the hydrodynamics of a strongly tidally forced tropical intertidal reef platform in the Kimberley region of northwestern Australia, where the spring tidal range exceeds 8 m. At this site, the flat and wide (˜1.4 km) reef platform is located slightly above mean sea level, such that during low tide the offshore water level can fall 4 m below the platform. While the reef always remained submerged over each tidal cycle, there were dramatic asymmetries in both the water levels and velocities on the reef, i.e., the flood duration lasted only ˜2 h versus ˜10 h for the ebb. These dynamics were investigated using a one-dimensional numerical model (SWASH) to solve the nonlinear shallow water equations with rapid (sub to supercritical) flow transitions. The numerical model revealed that as water drains off the reef, a critical flow point was established near the reef edge prior to the water discharging down the steep forereef. Despite this hydraulic control, bottom friction on the reef was still found to make a far greater contribution to elevating water levels on the reef platform and keeping it submerged over each tidal cycle. Finally, a simple analytical model more broadly shows how water levels on intertidal reef platforms functionally depend on properties of reef morphology, bottom roughness, and tidal conditions, revealing a set of parameters (a reef draining time-scale and friction parameter) that can be used to quantify how the water depth will fall on a reef during ebb tide.

  20. Measurement of the Earth tides with a MEMS gravimeter.

    PubMed

    Middlemiss, R P; Samarelli, A; Paul, D J; Hough, J; Rowan, S; Hammond, G D

    2016-03-31

    The ability to measure tiny variations in the local gravitational acceleration allows, besides other applications, the detection of hidden hydrocarbon reserves, magma build-up before volcanic eruptions, and subterranean tunnels. Several technologies are available that achieve the sensitivities required for such applications (tens of microgal per hertz(1/2)): free-fall gravimeters, spring-based gravimeters, superconducting gravimeters, and atom interferometers. All of these devices can observe the Earth tides: the elastic deformation of the Earth's crust as a result of tidal forces. This is a universally predictable gravitational signal that requires both high sensitivity and high stability over timescales of several days to measure. All present gravimeters, however, have limitations of high cost (more than 100,000 US dollars) and high mass (more than 8 kilograms). Here we present a microelectromechanical system (MEMS) device with a sensitivity of 40 microgal per hertz(1/2) only a few cubic centimetres in size. We use it to measure the Earth tides, revealing the long-term stability of our instrument compared to any other MEMS device. MEMS accelerometers--found in most smart phones--can be mass-produced remarkably cheaply, but none are stable enough to be called a gravimeter. Our device has thus made the transition from accelerometer to gravimeter. The small size and low cost of this MEMS gravimeter suggests many applications in gravity mapping. For example, it could be mounted on a drone instead of low-flying aircraft for distributed land surveying and exploration, deployed to monitor volcanoes, or built into multi-pixel density-contrast imaging arrays. PMID:27029276

  1. Measurement of the Earth tides with a MEMS gravimeter

    NASA Astrophysics Data System (ADS)

    Middlemiss, R. P.; Samarelli, A.; Paul, D. J.; Hough, J.; Rowan, S.; Hammond, G. D.

    2016-03-01

    The ability to measure tiny variations in the local gravitational acceleration allows, besides other applications, the detection of hidden hydrocarbon reserves, magma build-up before volcanic eruptions, and subterranean tunnels. Several technologies are available that achieve the sensitivities required for such applications (tens of microgal per hertz1/2): free-fall gravimeters, spring-based gravimeters, superconducting gravimeters, and atom interferometers. All of these devices can observe the Earth tides: the elastic deformation of the Earth’s crust as a result of tidal forces. This is a universally predictable gravitational signal that requires both high sensitivity and high stability over timescales of several days to measure. All present gravimeters, however, have limitations of high cost (more than 100,000 US dollars) and high mass (more than 8 kilograms). Here we present a microelectromechanical system (MEMS) device with a sensitivity of 40 microgal per hertz1/2 only a few cubic centimetres in size. We use it to measure the Earth tides, revealing the long-term stability of our instrument compared to any other MEMS device. MEMS accelerometers—found in most smart phones—can be mass-produced remarkably cheaply, but none are stable enough to be called a gravimeter. Our device has thus made the transition from accelerometer to gravimeter. The small size and low cost of this MEMS gravimeter suggests many applications in gravity mapping. For example, it could be mounted on a drone instead of low-flying aircraft for distributed land surveying and exploration, deployed to monitor volcanoes, or built into multi-pixel density-contrast imaging arrays.

  2. Turning the tide of public opinion on nuclear power

    SciTech Connect

    Cohen, B.L.

    1997-04-01

    Until the early 1970s, the tide of public opinion in the United States was strongly in favor of nuclear power. New power plants were coming on line frequently, and in 1973-74, there were close to 40 new orders per year for new reactors in the United States. Official government projections estimated 1000 operating reactors by the year 2000. Fuel reprocessing, plutonium recycle, and breeder reactor development were also proceeding smoothly and rapidly. But, in the mid-1970s, the tide suddenly turned against the nuclear industry. How did this come about? In the late 1960s, energetic and idealistic young people who had never experienced economic insecurity or World Wars came of age. Environmentalism was an attractive outlet for their activity in most of the Western world. In the United States, opposition to the Vietnam War, in which these young people had a personal stake, was even more popular at first, but by the early 1970s, Vietnam was winding down, and they turned also to Environmentalism. Numerous environmental groups started up, aided heavily by the favorable connotation of the very word {open_quotes}environmentalist{close_quotes} in the public mind. Their organizational experience, political savvy, and media connections gained from their antiwar protests were powerful assets. But the groups needed specific targets to attack, and they soon found that nuclear power was well-suited for that purpose. Here was a new technology, coming on at a very rapid pace. To the public, radiation was highly mysterious, and people were well aware that it could be dangerous. And, the word danger had taken on a new meaning. Previous generations were well acquainted with death and were much less averse to risk-taking than the generation of the 1970s.

  3. Emergency Protection from Aerosols

    SciTech Connect

    Cristy, G.A.

    2001-11-13

    Expedient methods were developed that could be used by an average person, using only materials readily available, to protect himself and his family from injury by toxic (e.g., radioactive) aerosols. The most effective means of protection was the use of a household vacuum cleaner to maintain a small positive pressure on a closed house during passage of the aerosol cloud. Protection factors of 800 and above were achieved.

  4. MISR Aerosol Typing

    NASA Technical Reports Server (NTRS)

    Kahn, Ralph A.

    2014-01-01

    AeroCom is an open international initiative of scientists interested in the advancement of the understanding of global aerosol properties and aerosol impacts on climate. A central goal is to more strongly tie and constrain modeling efforts to observational data. A major element for exchanges between data and modeling groups are annual meetings. The meeting was held September 20 through October 2, 1014 and the organizers would like to post the presentations.

  5. Monodisperse aerosol generator

    DOEpatents

    Ortiz, Lawrence W.; Soderholm, Sidney C.

    1990-01-01

    An aerosol generator is described which is capable of producing a monodisperse aerosol within narrow limits utilizing an aqueous solution capable of providing a high population of seed nuclei and an organic solution having a low vapor pressure. The two solutions are cold nebulized, mixed, vaporized, and cooled. During cooling, particles of the organic vapor condense onto the excess seed nuclei, and grow to a uniform particle size.

  6. RACORO aerosol data processing

    SciTech Connect

    Elisabeth Andrews

    2011-10-31

    The RACORO aerosol data (cloud condensation nuclei (CCN), condensation nuclei (CN) and aerosol size distributions) need further processing to be useful for model evaluation (e.g., GCM droplet nucleation parameterizations) and other investigations. These tasks include: (1) Identification and flagging of 'splash' contaminated Twin Otter aerosol data. (2) Calculation of actual supersaturation (SS) values in the two CCN columns flown on the Twin Otter. (3) Interpolation of CCN spectra from SGP and Twin Otter to 0.2% SS. (4) Process data for spatial variability studies. (5) Provide calculated light scattering from measured aerosol size distributions. Below we first briefly describe the measurements and then describe the results of several data processing tasks that which have been completed, paving the way for the scientific analyses for which the campaign was designed. The end result of this research will be several aerosol data sets which can be used to achieve some of the goals of the RACORO mission including the enhanced understanding of cloud-aerosol interactions and improved cloud simulations in climate models.

  7. Mesospheric Non-Migrating Tides Generated With Planetary Waves: II Influence of Gravity Waves

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

    We demonstrated that, in our model, non-linear interactions between planetary waves (PW) and migrating tides could generate in the upper mesosphere non-migrating tides with amplitudes comparable to those observed. The Numerical Spectral Model (NSM) we employ incorporates Hines Doppler Spread Parameterization for small-scale gravity waves (GW), which affect in numerous ways the dynamics of the mesosphere. The latitudinal (seasonal) reversals in the temperature and zonal circulation, which are largely caused by GWs (Lindzen, 198l), filter the PWs and contribute to the instabilities that generate the PWs. The PWs in turn are amplified by the momentum deposition of upward propagating GWs, as are the migrating tides. The GWs thus affect significantly the migrating tides and PWs, the building blocks of non-migrating tides. In the present paper, we demonstrate that GW filtering also contributes to the non-linear coupling between PWs and tides. Two computer experiments are presented to make this point. In one, we simply turn off the GW source to show the effect. In the second case, we demonstrate the effect by selectively suppressing the momentum source for the m = 0 non-migrating tides.

  8. Non-Migrating Diurnal Tides Generated with Planetary Waves in the Mesosphere

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

    We report here the results from a modeling study with our Numerical Spectral Model (NSM) that extends from the ground into thermosphere. The NSM incorporates Hines Doppler Spread Parameterization for small-scale gravity waves (GWs) and describes the major dynamical features of the atmosphere, including the wave driven equatorial oscillations (QBO and SAO), and the seasonal variations of tides and planetary waves. Accounting solely for the solar migrating tidal excitation sources, the NSM generates through dynamical interactions also non-migrating tides in the mesosphere that have amplitudes comparable to those observed. The model produces the diurnal (and semidiurnal) oscillations of the zonal mean (m = 0), and eastward and westward propagating tides for zonal wave numbers m = 1 to 4. To identify the mechanism of excitation for these tides, a numerical experiment is performed. The NSM is run without the heat source for the zonal-mean circulation and temperature variation, and the amplitudes of the resulting nonmigrating tides are then negligibly small. This leads to the conclusion that the planetary waves, which normally are excited in the NSM by instabilities but are suppressed in this case, generate the nonmigrating tides through nonlinear interactions with the migrating tides.

  9. Effects of dynamic long-period ocean tides on changes in Earth's rotation rate

    SciTech Connect

    Nam, Y.S.; Dickman, S.R. )

    1990-05-10

    As a generalization of the zonal response coefficient first introduced by Agnew and Farrell (1978), the authors define the zonal response function k of the solid earth-ocean system as the ratio, in the frequency domain, of the tidal change in Earth's rotation rate to the tide-generating potential. Amplitudes and phases of k for the monthly, fortnightly, and 9-day lunar tides are estimated from 2 1/2 years of very long baseline interferometry UTI observations (both 5-day and daily time series), corrected for atmospheric angular momentum effects using NMC wind and pressure series. Using the dynamic ocean tide model of Dickman (1988a, 1989a), the authors predict amplitudes and phases of k for an elastic earth-ocean system. The predictions confirm earlier results which found that dynamic effects of the longer-period ocean tides reduce the amplitude of k by about 1%. However, agreement with the observed k is best achieved for all three tides if the predicted tide amplitudes are combined with the much larger satellite-observed ocean tide phases; in these cases the dynamic tidal effects reduce k by up to 8%. Finally, comparison between the observed and predicted amplitudes of k implies that anelastic effects on Earth's rotation at periods less than fortnightly cannot exceed 2%.

  10. Seasonal variation of Martian middle atmosphere tides observed by the Mars Climate Sounder

    NASA Astrophysics Data System (ADS)

    Wu, Zhaopeng; Li, Tao; Dou, Xiankang

    2015-12-01

    The increased local time coverage retrieved from the Mars Climate Sounder on board the Mars Reconnaissance Orbiter enables the direct extraction of thermal tides in the Mars middle atmosphere. Using temperature profiles from Mars years 30 to 32, we studied the latitudinal and seasonal variations in the tides and stationary planetary waves with zonal wave numbers s = 1-3. The amplitude of the migrating diurnal tide exhibits strong semiannual variations in both the equatorial region and the middle latitudes of Southern Hemisphere. The migrating semidiurnal tide (SW2) shows clear semiannual variations in the equatorial region and the middle latitudes of Northern Hemisphere but an annual variation in the Southern Hemisphere. The spatial and temporal correlations between the SW2 amplitude and the density-scaled opacity of both the water ice and dust in the equatorial region may provide a possible explanation for the tidal forcing of SW2. Three Kelvin modes with zonal wave numbers 1-3 (DE1-DE3) have significant seasonal variations in the equatorial region. DE1 appears to have a semiannual variation, whereas DE2 and DE3 have clear annual variations. Herein, for the first time, we have extracted the westward propagating diurnal tide with s = 2 and 3 and semidiurnal tide with s = 1 in the Mars middle atmosphere using observational data. All three waves have asymmetric latitudinal distributions, which should correspond to their possible excitation source, i.e., nonlinear interactions between stationary planetary waves and migrating tides.

  11. Temporal variations in internal tide multimodal structure on the continental shelf, South China Sea

    NASA Astrophysics Data System (ADS)

    Gao, Dalu; Jin, Guangzhen; Lü, Xianqing

    2016-04-01

    Temporal variations in multimodal structures of diurnal (D 1) and semidiurnal (D 2) internal tides were investigated on the continental slope of the Dongsha Plateau, based on 2-month moored acoustic Doppler current profiler observations. Harmonic analysis indicated that the D 1 components (K 1 and O 1) dominated the internal tide field. The vertical structure of the K 1 constituent presented a first-mode structure while the M 2 constituent seemed to exhibit a high-mode structure. Amplitude spectra analysis of the current data revealed differences in baroclinic current amplitudes between different water depths. Temporal variations in modal structures ware analyzed, based on the D 1 and D 2 baroclinic tides extracted from the baroclinic velocity field with band-pass filters. Analysis showed that the magnitude of the D 1 internal tide current was much larger than the D 2 current, and temporal variations in the modal structure of the D 1 internal tide occurred on an approximately fortnightly cycle. The EOF analyses revealed temporal transformation of multimodal structures for D 1 and D 2 internal tides. The enhancement of the D 1 internal tide was mainly due to the superposition of K 1 and O 1, according to the temporal variation of coherent kinetic energy.

  12. Numerical Study of the Interaction Between an Internal Tide and Mesoscale/Submesoscale Turbulence

    NASA Astrophysics Data System (ADS)

    Klein, P.; Ponte, A.

    2014-12-01

    Interactions between internal tides and mesoscale eddies are believed to be responsible for the incoherency of internal tides observed globally. This incoherency complicates the analysis of future high resolution altimetric missions (SWOT, COMPIRA). Attempts at quantifying the product of these interactions have been achieved with models of the ocean global circulation. These models resolve however the first few vertical modes of internal tide and their ability to represent interactions between internal tides and balanced circulation has to be tested against controlled high resolution numerical simulations. We present here first attempts in order to study such interactions in a controlled idealized setting. High resolution (1 km horizontal grid size) numerical simulations of mesoscale/submesoscale turbulence are produced by destabilizing a baroclinic jet in a zonally-periodic channel. An plane wave internal tide is generated inside the domain thanks to a localized wave-maker and propagates through the mesoscale/submesoscale turbulence. We quantify the level of incoherency of the internal tide and study how this level depends on the modal structure of the internal tide and the intensity of the mesoscale/submesoscale turbulence.

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

    NASA Astrophysics Data System (ADS)

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

    2004-04-01

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

  14. Impacts of man-made landscape features on numbers of estuarine waterbirds at low tide.

    PubMed

    Burton, Niall H K; Armitage, Michael J S; Musgrove, Andrew J; Rehfisch, Mark M

    2002-12-01

    The potential impact of human disturbance on wintering waterbirds using intertidal mudflats was considered by relating their numbers to the presence of nearby footpaths, roads, railroads, and towns. Data were obtained for six English estuaries from the Wetland Bird Survey Low Tide Count scheme. Counts were undertaken monthly from November to February, and data were available for an average of 2.8 years per estuary for the period 1992-1993 to 1999-2000. Count sections and the positions of man-made landscape features were mapped using a GIS. Generalized linear models tested whether bird numbers varied according to the estuary, month, area, whether or not the section bordered water, and the proportion of each section within a specified distance of each landscape feature. In addition, the proximity of sections to the nearest footpath access point was considered. Numbers of six of nine species, northern shelduck (Tadorna tadorna), red knot (Calidris canutus), dunlin (Calidris alpina), black-tailed godwit (Limosa limosa), Eurasian curlew (Numenius arquata) and common redshank (Tringa totanus), were significantly lower where a footpath was close to a count section, while those of brant (Branta bernicla) were greater. Northern shelduck, black-bellied plover (Pluvialis squatarola), dunlin, and black-tailed godwit numbers were reduced close to railroads and those of common ringed plover (Charadrius hiaticula), black-bellied plover, and Eurasian curlew close to roads. Common ringed plover numbers were greater close to towns. The relative distances to which species were affected by footpaths corresponded to published information concerning their flight distances in response to human disturbance. The study provided evidence that sustained disturbance associated with footpaths, roads, and railroads reduced local habitat quality for waterbirds and the carrying capacity of estuaries. PMID:12402099

  15. Dtection of Sea Level Rise within the Arabian Gulf Using Space Based GNSS Measurements and Insitu Tide Gauge data

    NASA Astrophysics Data System (ADS)

    Alothman, Abdulaziz; Ayhan, Mehmet

    In the 21st century, sea level rise is expected to be about 30 cm or even more (up to 60 cm). Saudi Arabia has very long coasts of about 3400 km and hundreds of islands. Therefore, sea level monitoring may be important in particular along coastal low lands on Red Sea and Arabian Gulf coasts. Arabian Gulf is connected to Indian Ocean and lying along a parallel course in the south-west of the Zagros Trust Belt. We expect vertical land motion within the area due to both tectonic structures of the Arabian Peninsula and oil production activities. Global Navigation Satellite System (GNSS) Continues observations were used to estimate the vertical crustal motion. Bahrain International GPS Service (IGS-GPS) station is the only continuous GPS station accessible in the region, and it is close to the Mina Sulman tide gauge station in Bahrain. The weekly GPS time series of vertical component at Bahrain IGS-GPS station referring to the ITRF97 from 1999.2 to 2008.6 are used in the computation. We fitted a linear trend with an annual signal and a break to the GPS vertical time series and found a vertical land motion rate of 0.46 0.11 mm/yr. To investigate sea level variation within the west of Arabian Gulf, monthly means of sea level at 13 tide gauges along the coast of Saudi Arabia and Bahrain, available in the database of the Permanent Service for Mean Sea Level (PSMSL), are studied. We analyzed separately the monthly mean sea level measurements at each station, and estimated secular sea level rate by a robust linear trend fitting. We computed the average relative sea level rise rate of 1.96 0.21 mm/yr within the west of Arabian Gulf based on 4 stations spanning longer than 19 years. Sea level rates at the stations are first corrected for vertical land motion contamination using the ICE-5G v1.2 VM4 Glacial Isostatic Adjustment (GIA) model, and the average sea level rate is found 2.27 0.21 mm/yr. Assuming the vertical rate at Bahrain IGS-GPS station represents the vertical rate

  16. Estimation of aerosol optical properties from all-sky imagers

    NASA Astrophysics Data System (ADS)

    Kazantzidis, Andreas; Tzoumanikas, Panagiotis; Salamalikis, Vasilios; Wilbert, Stefan; Prahl, Christoph

    2015-04-01

    Aerosols are one of the most important constituents in the atmosphere that affect the incoming solar radiation, either directly through absorbing and scattering processes or indirectly by changing the optical properties and lifetime of clouds. Under clear skies, aerosols become the dominant factor that affect the intensity of solar irradiance reaching the ground. It has been shown that the variability in direct normal irradiance (DNI) due to aerosols is more important than the one induced in global horizontal irradiance (GHI), while the uncertainty in its calculation is dominated by uncertainties in the aerosol optical properties. In recent years, all-sky imagers are used for the detection of cloud coverage, type and velocity in a bouquet of applications including solar irradiance resource and forecasting. However, information about the optical properties of aerosols could be derived with the same instrumentation. In this study, the aerosol optical properties are estimated with the synergetic use of all-sky images, complementary data from the Aerosol Robotic Network (AERONET) and calculations from a radiative transfer model. The area of interest is Plataforma Solar de Almería (PSA), Tabernas, Spain and data from a 5 month period are analyzed. The proposed methodology includes look-up-tables (LUTs) of diffuse sky radiance of Red (R), Green (G) and Blue (B) channels at several zenith and azimuth angles and for different atmospheric conditions (Angström α and β, single scattering albedo, precipitable water, solar zenith angle). Based on the LUTS, results from the CIMEL photometer at PSA were used to estimate the RGB radiances for the actual conditions at this site. The methodology is accompanied by a detailed evaluation of its robustness, the development and evaluation of the inversion algorithm (derive aerosol optical properties from RGB image values) and a sensitivity analysis about how the pre-mentioned atmospheric parameters affect the results.

  17. Mesospheric Non-Migrating Tides Generated With Planetary Waves. 1; Characteristics

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

    We discuss results from a modeling study with our Numerical Spectral Model (NSM) that specifically deals with the non-migrating tides generated in the mesosphere. The NSM extends from the ground to the thermosphere, incorporates Hines' Doppler Spread Parameterization for small-scale gravity waves (GWs), and it describes the major dynamical features of the atmosphere including the wave driven equatorial oscillations (QBO and SAO), and the seasonal variations of tides and planetary waves. Accounting solely for the excitation sources of the solar migrating tides, the NSM generates through dynamical interactions also non-migrating tides in the mesosphere that are comparable in magnitude to those observed. Large non-migrating tides are produced in the diurnal and semi-diurnal oscillations for the zonal mean (m = 0) and in the semidiurnal oscillation for m = 1. In general, significant eastward and westward propagating tides are generated for all the zonal wave numbers m = 1 to 4. To identify the cause, the NSM is run without the solar heating for the zonal mean (m = 0), and the amplitudes of the resulting non-migrating tides are then negligibly small. In this case, the planetary waves are artificially suppressed, which are generated in the NSM through instabilities. This leads to the conclusion that the non-migrating tides are generated through non-linear interactions between planetary waves and migrating tides, as Forbes et al. and Talaat and Liberman had proposed. In an accompanying paper, we present results from numerical experiments, which indicate that gravity wave filtering contributes significantly to produce the non-linear coupling that is involved.

  18. Earth tides observed by gravimeter and GPS in Juneau, Southeastern Alaska

    NASA Astrophysics Data System (ADS)

    Sato, T.; Miura, S.; Ohta, Y.; Fujimoto, H.; Sun, W.; Larsen, C.; Heavner, M.; Kaufman, A. M.; Freymueller, J. T.

    2007-12-01

    We have analyzed the gravity data obtained at the Egan Library of University of Alaska, Southeast (UAS) and the GPS data obtained at a PBO site in Juneau, and we compared the obtained tidal amplitudes and phases with those estimated from the predicted tides including both effects of the body tide and ocean tide. To improve the accuracy in prediction, we also computed the regional ocean tide model in Southeastern Alaska (SE-AK). Our comparison results suggest; (1) By taking into account the ocean tide effect including the regional ocean tide model, the amplitude differences between the observation and the predicted body tide is remarkably reduced for both the gravity and displacement tides (e.g. for the M2 constituent, 8.04 microGal to 0.02 microGal (1 microGal=1E-8 m/s/s), and 2.43 cm to the order of 0.01 cm for the vertical displacement), (2) The PPP method (Zumberge et al., 1997) used to extract the tidal signals from the original GPS time series works well to recover the tidal signals. Although the GPS analysis results still contain the noises which may be considered to be the meteorological effects, we may conclude that the GPS observation surely detects the tidal signals with the sub cm accuracy or better for some of the tidal constituents. The viscoelastic effect in gravity tides is estimated to be the order of 0.05 ?Gal for the M2 constituent in Juneau. The magnitude is equivalent to the analysis error for our gravity data. Increasing the accuracy of calibration of the gravimeter and the regional ocean model in SE-AK is needed to constrain the Earth's viscoelastic response to the tidal force tightly.

  19. A numerical model of nonmigrating diurnal tides between the surface and 65 km

    NASA Technical Reports Server (NTRS)

    Lieberman, Ruth S.; Leovy, Conway B.

    1995-01-01

    Observations of surface pressure and middle atmosphere temperatures and winds indicate that a substantial nonmigrating component is present in the diurnal tide. The nonmigrating tides, which propagate with a zonal phase speed that is different from the earth's rotation, are attributed to the diurnal heating of geographically fixed sources. In this study we utilize a classical tidal model to examine the propagation characteristics of diurnal tides. The global fields of tropospheric sensible, radiative, and latent heating used to drive the model are supplied from summer and winter diurnal climatologies of the National Center for Atmospheric Research (NCAR) Community Climate Model (CCM2). A novel aspect of this study is the focus on the relative importance of the nonmigrating components. The classical model successfully reproduces many observed features of the low-latitude diurnal surface pressure tides. In the middle atmosphere, the simulated migrating (or sun-synchronous) tide shows qualitative agreement with November-March Limb Infrared Monitor of the Stratosphere (LIMS) observations. Tropospheric solar heating is clearly the dominant driving force for the migrating tide, with secondary contributions from boundary-layer sensible heating and tropospheric latent heat release. The leading modes of the zonal mean tide are also driven chiefly by tropospheric solar heating. The higher-order modes of the zonal mean and eastward propagating tides may be attributed to the joint effects of tropospheric solar heating, sensible heating, and latent heat release. The LIMS and other data reveal features that cannot be explained or examined within the context of the classical model used in the present study. These include upward phase propagation, vertical attenuation, and temporal variations in the migrating diurnal tide.

  20. Twenty Years of Progress on Global Ocean Tides: The Impact of Satellite Altimetry

    NASA Technical Reports Server (NTRS)

    Egbert, Gary; Ray, Richard

    2012-01-01

    At the dawn of the era of high-precision altimetry, before the launch of TOPEX/Poseidon, ocean tides were properly viewed as a source of noise--tidal variations in ocean height would represent a very substantial fraction of what the altimeter measures, and would have to be accurately predicted and subtracted if altimetry were to achieve its potential for ocean and climate studies. But to the extent that the altimetry could be severely contaminated by tides, it also represented an unprecedented global-scale tidal data set. These new data, together with research stimulated by the need for accurate tidal corrections, led to a renaissance in tidal studies in the oceanographic community. In this paper we review contributions of altimetry to tidal science over the past 20 years, emphasizing recent progress. Mapping of tides has now been extended from the early focus on major constituents in the open ocean to include minor constituents, (e.g., long-period tides; non-linear tides in shelf waters, and in the open ocean), and into shallow and coastal waters. Global and spatially local estimates of tidal energy balance have been refined, and the role of internal tide conversion in dissipating barotropic tidal energy is now well established through modeling, altimetry, and in situ observations. However, energy budgets for internal tides, and the role of tidal dissipation in vertical ocean mixing remain controversial topics. Altimetry may contribute to resolving some of these important questions through improved mapping of low-mode internal tides. This area has advanced significantly in recent years, with several global maps now available, and progress on constraining temporally incoherent components. For the future, new applications of altimetry (e.g., in the coastal ocean, where barotropic tidal models remain inadequate), and new mission concepts (studies of the submesoscale with SWOT, which will require correction for internal tides) may bring us full circle, again pushing

  1. Global ocean tides. Part IV. The diurnal luni-solar declination tide (K1), atlas of tidal charts and maps. Final report

    SciTech Connect

    Schwiderski, E.W.

    1981-05-15

    In Part I of this report (A060 913), a unique hydrodynamical interpolation technique was introduced, extensively tested, and evaluated in order to partial global ocean tides in great detail and with a high degree of accuracy. This novel method has been applied to construct the diurnal luni-solar declination (K1) 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 K1 ocean tide is found to resemble qualitatively the semidiurnal M2 and S2 tides presented in Parts II (AD-A084 694) and III (AD-A104 333) of this report. However, major shifts of the positions of the amphidromes are apparent.

  2. AEROSOL CHARACTERIZATION WITH CENTRIFUCAL AEROSOL SPECTROMETERS: THEORY AND EXPERIMENT

    EPA Science Inventory

    A general mathematical model describing the motion of particles in aerosol centrifuges has been developed. t has been validated by comparisons of theoretically predicted calibration sites with experimental data from tests sizing aerosols in instruments of three different spiral d...

  3. Tide-induced fingering flow during submarine groundwater discharge

    NASA Astrophysics Data System (ADS)

    Greskowiak, Janek

    2013-04-01

    Submarine groundwater discharge (SGD) is a relevant component of the hydrological cycle (Moore, 2010). The discharge of fresh groundwater that originated from precipitation on the land typically occurs at the near shore scale (~ 10m-100m) and the embayment scale (~ 100m - 10km) (Bratton, 2010). In the recent years a number of studies revealed that tidal forcing has an important effect on the fresh SGD pattern in the beach zone, i.e., it leads to the formation of an upper saline recirculation cell and a lower "freshwater discharge tube" (Boufadel, 2000, Robinson et al., 2007; Kuan et al., 2012). Thereby the discharge of the fresh groundwater occurs near the low-tide mark. The shape and extent of the upper saline recirculation cell is mainly defined by the tidal amplitude, beach slope, fresh groundwater discharge rate and hydraulic conductivity (Robinson et al., 2007). In spite of fact that in this case sea water overlies less denser freshwater, all previous modeling studies suggested that the saline recirculation cell and the freshwater tube are rather stable. However, new numerical investigations indicate that there maybe realistic cases where the upper saline recirculation cell becomes unstable as a result of the density contrast to the underlying freshwater tube. In these cases salt water fingers develop and move downward, thereby penetrating the freshwater tube. To the author's knowledge, the present study is the first that illustrate the possibility of density induced fingering flow during near shore SGD. A total of 240 high resolution simulations with the density dependent groundwater modelling software SEAWAT-2000 (Langevin et al., 2007) has been carried out to identify the conditions under which salt water fingering starts to occur. The simulations are based on the field-scale model setup employed in Robinson et al. (2007). The simulation results indicate that a very flat beach slope of less than 1:35, a hydraulic conductivity of 10 m/d and already a tidal

  4. De-tiding Short Tsunami Records at DART Buoys

    NASA Astrophysics Data System (ADS)

    Tolkova, E.

    2008-12-01

    The tsunami forecast system being developed at the Pacific Marine Environmental Laboratory relies on a network of DART buoys to obtain real-time measurements of tsunami wave height. A tsunami wave in an open ocean is however often a few centimeters in amplitude or less. This signal is masked by the much more powerful tidal component, with typical amplitude of one meter or more. Therefore, for high-quality tsunami measurements, the tidal component of a DART record must be removed almost perfectly. For instance, for 1 meter amplitude of the tidal motion (70 cm root-mean-square (RMS) value), 99.998% of the total tidal variance needs be removed for the residual to stay under 3 mm (RMS). Two major approaches to detiding a record are either to predict a tide, or to filter it out. Tidal prediction employs a formalism of harmonic constituents. The constituents' phases and amplitudes have to be determined for each and every individual buoy, which optimally requires an analysis of a particular buoy's record for one or more years. Tidal predictions alone can not provide the desired accuracy. Digital filtering has the major difficulty of detecting a tsunami at the beginning of the event, when the tsunami record at a DART buoy is less than one full wave (a peak and a trough). Needless to say, from the point of view of real- time tsunami forecast, the first appearance of a tsunami wave peak on a DART record is when the precise measurement of the tsunami characteristics is essential. In this work, a de-tiding technique is presented, which can reliably detect a tsunami wave in a DART signal with a few mm accuracy from the very beginning of the tsunami record. The method is based on an empirical observation that sections of tidal records M-reading long regardless of when and where they were taken, can be expressed as a linear combination of several M-dimensional vectors derived via principal component analysis of DART records. Fitting a section of a DART record with these functions

  5. Aerosol chemistry in GLOBE

    NASA Technical Reports Server (NTRS)

    Clarke, Antony D.; Rothermel, Jeffry; Jarzembski, Maurice A.

    1993-01-01

    This task addresses the measurement and understanding of the physical and chemical properties of aerosol in remote regions that are responsible for aerosol backscatter at infrared wavelengths. Because it is representative of other clean areas, the remote Pacific is of extreme interest. Emphasis is on the determination size dependent aerosol properties that are required for modeling backscatter at various wavelengths and upon those features that may be used to help understand the nature, origin, cycling and climatology of these aerosols in the remote troposphere. Empirical relationships will be established between lidar measurements and backscatter derived from the aerosol microphysics as required by the NASA Doppler Lidar Program. This will include the analysis of results from the NASA GLOBE Survey Mission Flight Program. Additional instrument development and deployment will be carried out in order to extend and refine this data base. Identified activities include participation in groundbased and airborne experiments. Progress to date includes participation in, analysis of, and publication of results from Mauna Loa Backscatter Intercomparison Experiment (MABIE) and Global Backscatter Experiment (GLOBE).

  6. Biological aerosol background characterization

    NASA Astrophysics Data System (ADS)

    Blatny, Janet; Fountain, Augustus W., III

    2011-05-01

    To provide useful information during military operations, or as part of other security situations, a biological aerosol detector has to respond within seconds or minutes to an attack by virulent biological agents, and with low false alarms. Within this time frame, measuring virulence of a known microorganism is extremely difficult, especially if the microorganism is of unknown antigenic or nucleic acid properties. Measuring "live" characteristics of an organism directly is not generally an option, yet only viable organisms are potentially infectious. Fluorescence based instruments have been designed to optically determine if aerosol particles have viability characteristics. Still, such commercially available biological aerosol detection equipment needs to be improved for their use in military and civil applications. Air has an endogenous population of microorganisms that may interfere with alarm software technologies. To design robust algorithms, a comprehensive knowledge of the airborne biological background content is essential. For this reason, there is a need to study ambient live bacterial populations in as many locations as possible. Doing so will permit collection of data to define diverse biological characteristics that in turn can be used to fine tune alarm algorithms. To avoid false alarms, improving software technologies for biological detectors is a crucial feature requiring considerations of various parameters that can be applied to suppress alarm triggers. This NATO Task Group will aim for developing reference methods for monitoring biological aerosol characteristics to improve alarm algorithms for biological detection. Additionally, they will focus on developing reference standard methodology for monitoring biological aerosol characteristics to reduce false alarm rates.

  7. SURVIVAL OF BACTERIA DURING AEROSOLIZATION

    EPA Science Inventory

    One form of commercial application of microorganisms, including genetically engineered microorganisms is as an aerosol. To study the effect of aerosol-induced stress on bacterial survival, nonrecombinant spontaneous antibiotic-resistant mutants of four organisms, Enterobacter clo...

  8. Other medications for aerosol delivery.

    PubMed

    Rubin, Bruce K

    2006-01-01

    Although aerosol therapy is most commonly used to treat asthma and COPD, there are a large number of aerosol medications now used or in development for other diseases. Mucoactive agents have long been available by aerosol, but now we have truly effective drugs to improve effective airway clearance including dornase alfa, hyperosmolar saline, and aerosol surfactant. Inhaled antibiotics are available for the treatment of cystic fibrosis, bronchiectasis and other chronic airway infections. With the development of devices that can target aerosol to the deep lung, the opportunity to deliver medications systemically by the aerosol route has become a reality. Insulin, recently approved in the US as aerosol therapy, and other peptides are systemically absorbed from the distal airway and alveolus. Aerosol gene transfer therapy to correct abnormalities associated with cystic fibrosis, primary ciliary dyskinesia and other airway diseases also holds great potential. PMID:16798603

  9. Atmospheric Chemistry: Nature's plasticized aerosols

    NASA Astrophysics Data System (ADS)

    Ziemann, Paul J.

    2016-01-01

    The structure of atmospheric aerosol particles affects their reactivity and growth rates. Measurements of aerosol properties over the Amazon rainforest indicate that organic particles above tropical rainforests are simple liquid drops.

  10. The thermodynamic and kinetic impacts of organics on marine aerosols

    NASA Astrophysics Data System (ADS)

    Crahan, Kathleen

    Organics can change the manner in which aerosols scatter radiation directly as hydrated aerosols and indirectly as in-cloud activated aerosols, through changing the solution activity, the surface tension, and the accommodation coefficient of the hydrated aerosol. This work explores the kinetic and thermodynamic impacts of the organic component of marine aerosols through data collected over four field campaigns and through several models used to reproduce observations. The Rough Evaporation Duct (RED) project was conducted in the summer of 2001 off the coast of Oahu using the Twin Otter Aircraft and the Floating Instrument Platform research platform for data collection. The Cloud-Aerosol Research in the Marine Atmosphere (CARMA) campaigns were conducted over three summers (2002, 2004, 2005) off the coast of Monterey, California. During the CARMA campaigns, a thick, moist, stratocumulus deck was present during most days, and the Twin Otter Aircraft was the primary research platform used to collect data. However, the research goals and exact instrumentation onboard the Twin Otter varied from campaign to campaign, and each data set was analyzed individually. Data collected from CARMA I were used to explore the mechanism of oxalic acid production in cloud droplets. Oxalate was observed in the clouds in excess to below cloud concentrations by an average of 0.11 mug m-3, suggesting an in-cloud production. The tentative identification in cloud water of an intermediate species in the aqueous oxalate production mechanism lends further support to an in-cloud oxalate source. The data sets collected during the RED campaign and the CARMA II and CARMA III campaigns were used to investigate the impact of aerosol chemical speciation on aerosol hygroscopic behavior. Several models were used to correlate the observations in the subsaturated regime to theory including an explicit thermodynamic model, simple Kohler theory, and a parameterization of the solution activity. These models

  11. Mediterranean circulation response to enhanced resolution and tide

    NASA Astrophysics Data System (ADS)

    Carillo, Adriana; Sannino, Gianmaria; Pisacane, Giovanna; Naranjo, Cristina

    2015-04-01

    The Mediterranean Thermohaline circulation (MTHC) is sustained by the atmospheric forcing and controlled by the exchange of water with the neighboring Atlantic ocean through the Gibraltar Strait (SoG). The counter-flowing fluxes of Atlantic and Mediterranean waters are subject to tide-induced vigorous mixing within the Strait, where tidal forcing also affects the hydraulic control of volume fluxes, both processes determining heat, salt, and mass fluxes into the Mediterranean. A correct prescription of the lateral boundary condition at the Gibraltar inlet can therefore only be achieved by explicitly including the Gibraltar Strait in the numerical domain at a spatial resolution sufficient to account for both the fast barotropic tidal signal propagating eastward from the Atlantic Ocean and the baroclinic mixing processes occurring within the strait. The aim of this work is to evaluate the separate and joint long-term effects of increased resolution in the strait, SoG dynamics, and tides on the simulated MTHC by comparing results from multi-year hindcast numerical simulations. The model used is a regional Mediterranean version of the Massachusetts Institute of Technology general circulation model. A non-uniform curvilinear orthogonal grid with a resolution of 1/16°x1/16° in its regular portion inside the Mediterranean Sea and a refinement in the SoG reaching a maximum horizontal resolution of about 1/200° x 1/200° has been used. 72 unevenly spaced z-levels have been prescribed in the vertical, with resolution ranging from 1 m to 200 m. The surface atmospheric forcing has been provided by the dynamical downscaling of the ECMWF-ERA40 air-sea fluxes reanalysis via a regional model. Results from two multi-year simulations differing only for the inclusion/omission of the four dominant constituents of the semi-diurnal and diurnal internal and lateral tidal forcing have been compared analyzing in details the differences in the MTHC with particular attention on the deep

  12. Practical analysis of tide gauges records from Antarctica

    NASA Astrophysics Data System (ADS)

    Galassi, Gaia; Spada, Giorgio

    2015-04-01

    We have collected and analyzed in a basic way the currently available time series from tide gauges deployed along the coasts of Antarctica. The database of the Permanent Service for Mean Sea Level (PSMSL) holds relative sea level information for 17 stations, which are mostly concentrated in the Antarctic Peninsula (8 out of 17). For 7 of the PSMSL stations, Revised Local Reference (RLR) monthly and yearly observations are available, spanning from year 1957.79 (Almirante Brown) to 2013.95 (Argentine Islands). For the remaining 11 stations, only metric monthly data can be obtained during the time window 1957-2013. The record length of the available time series is not generally exceeding 20 years. Remarkable exceptions are the RLR station of Argentine Island, located in the Antarctic Peninsula (AP) (time span: 1958-2013, record length: 54 years, completeness=98%), and the metric station of Syowa in East Antarctica (1975-2012, 37 years, 92%). The general quality (geographical coverage and length of record) of the time series hinders a coherent geophysical interpretation of the relative sea-level data along the coasts of Antarctica. However, in an attempt to characterize the relative sea level signals available, we have stacked (i.e., averaged) the RLR time series for the AP and for the whole Antarctica. The so obtained time series have been analyzed using simple regression in order to estimate a trend and a possible sea-level acceleration. For the AP, the the trend is 1.8 ± 0.2 mm/yr and for the whole Antarctica it is 2.1 ± 0.1 mm/yr (both during 1957-2013). The modeled values of Glacial Isostatic Adjustment (GIA) obtained with ICE-5G(VM2) using program SELEN, range between -0.7 and -1.6 mm/yr, showing that the sea-level trend recorded by tide gauges is strongly influenced by GIA. Subtracting the average GIA contribution (-1.1 mm/yr) to observed sea-level trend from the two stacks, we obtain 3.2 and 2.9 mm/yr for Antarctica and AP respectively, which are interpreted

  13. Modeling the Ocean Tide for Tidal Power Generation Applications

    NASA Astrophysics Data System (ADS)

    Kawase, M.; Gedney, M.

    2014-12-01

    Recent years have seen renewed interest in the ocean tide as a source of energy for electrical power generation. Unlike in the 1960s, when the tidal barrage was the predominant method of power extraction considered and implemented, the current methodology favors operation of a free-stream turbine or an array of them in strong tidal currents. As tidal power generation moves from pilot-scale projects to actual array implementations, numerical modeling of tidal currents is expected to play an increasing role in site selection, resource assessment, array design, and environmental impact assessment. In this presentation, a simple, coupled ocean/estuary model designed for research into fundamental aspects of tidal power generation is described. The model consists of a Pacific Ocean-size rectangular basin and a connected fjord-like embayment with dimensions similar to that of Puget Sound, Washington, one of the potential power generation sites in the United States. The model is forced by an idealized lunar tide-generating potential. The study focuses on the energetics of a tidal system including tidal power extraction at both global and regional scales. The hyperbolic nature of the governing shallow water equations means consequence of tidal power extraction cannot be limited to the local waters, but is global in extent. Modeling power extraction with a regional model with standard boundary conditions introduces uncertainties of 3 ~ 25% in the power extraction estimate depending on the level of extraction. Power extraction in the model has a well-defined maximum (~800 MW in a standard case) that is in agreement with previous theoretical studies. Natural energy dissipation and tidal power extraction strongly interact; for a turbine array of a given capacity, the higher the level of natural dissipation the lower the power the array can extract. Conversely, power extraction leads to a decrease in the level of natural dissipation (Figure) as well as the tidal range and the

  14. Quantifying the sensitivity of aerosol optical depths retrieved from MSG SEVIRI to a priori data

    NASA Astrophysics Data System (ADS)

    Bulgin, C. E.; Palmer, P. I.; Merchant, C. J.; Siddans, R.; Poulsen, C.; Grainger, R. G.; Thomas, G.; Carboni, E.; McConnell, C.; Highwood, E.

    2009-12-01

    Radiative forcing contributions from aerosol direct and indirect effects remain one of the most uncertain components of the climate system. Satellite observations of aerosol optical properties offer important constraints on atmospheric aerosols but their sensitivity to prior assumptions must be better characterized before they are used effectively to reduce uncertainty in aerosol radiative forcing. We assess the sensitivity of the Oxford-RAL Aerosol and Cloud (ORAC) optimal estimation retrieval of aerosol optical depth (AOD) from the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) to a priori aerosol data. SEVIRI is a geostationary satellite instrument centred over Africa and the neighbouring Atlantic Ocean, routinely sampling desert dust and biomass burning outflow from Africa. We quantify the uncertainty in SEVIRI AOD retrievals in the presence of desert dust by comparing retrievals that use prior information from the Optical Properties of Aerosol and Cloud (OPAC) database, with those that use measured aerosol properties during the Dust Outflow and Deposition to the Ocean (DODO) aircraft campaign (August, 2006). We also assess the sensitivity of retrieved AODs to changes in solar zenith angle, and the vertical profile of aerosol effective radius and extinction coefficient input into the retrieval forward model. Currently the ORAC retrieval scheme retrieves AODs for five aerosol types (desert dust, biomass burning, maritime, urban and continental) and chooses the most appropriate AOD based on the cost functions. We generate an improved prior aerosol speciation database for SEVIRI based on a statistical analysis of a Saharan Dust Index (SDI) determined using variances of different brightness temperatures, and organic and black carbon tracers from the GEOS-Chem chemistry transport model. This database is described as a function of season and time of day. We quantify the difference in AODs between those chosen based on prior information from the SDI and GEOS

  15. Aerosol characterization with lidar methods

    NASA Astrophysics Data System (ADS)

    Sugimoto, Nobuo; Nishizawa, Tomoaki; Shimizu, Atsushi; Matsui, Ichiro

    2014-08-01

    Aerosol component analysis methods for characterizing aerosols were developed for various types of lidars including polarization-sensitive Mie scattering lidars, multi-wavelength Raman scattering lidars, and multi-wavelength highspectral- resolution lidars. From the multi-parameter lidar data, the extinction coefficients for four aerosol components can be derived. The microphysical parameters such as single scattering albedo and effective radius can be also estimated from the derived aerosol component distributions.

  16. Resonant Third-Degree Diurnal Tides in the Seas Off Western Europe

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

    Third-degree diurnal tides are estimated from long time series of sea level measurements at three North Atlantic tide gauges. Although their amplitudes are only a few mm or less, their admittances are far larger than those of second-degree diurnal tides, just as Cartwright discovered for the M(sub 1) constituent. The tides are evidently resonantly enhanced owing to high spatial correlation between the third-degree spherical harmonic of the tidal potential and a near-diurnal oceanic normal mode that is most pronounced in the North Atlantic. By estimating the ocean tidal response across the diurnal band (5 tidal constituents plus nodal modulations), the period and Q of this mode and one nearby mode are estimated.

  17. Model of Semidiurnal Pseudo Tide in the High-Latitude Upper Mesosphere

    NASA Technical Reports Server (NTRS)

    Talaat, E. R.; Mayr, H. G.

    2011-01-01

    We present numerical results for the m = 1 meridional winds of semi diurnal oscillations in the high-latitude upper mesosphere, which are generated in the Numerical Spectral Model (NSM) without solar excitations of the tides. Identified with heuristic computer runs, the pseudo tides attain amplitudes that are, at times, as large as the non-migrating tides produced with standard solar forcing. Under the influence of parameterized gravity waves, the nonlinear NSM generates internal oscillations like the quasi-biennial oscillation, that are produced with periods favored by the dynamical properties of the system. The Coriolis force would favor at polar latitudes the excitation of the 12-hour periodicity. This oscillation may help explain the large non-migrating semidiurnal tides that are observed in the region with ground-based and satellite measurements.

  18. The effect of error in theoretical Earth tide on calibration of borehole strainmeters

    USGS Publications Warehouse

    Langbein, John

    2010-01-01

    Since the installation of borehole strainmeters into the ground locally distorts the strain in the rock, these strainmeters require calibration from a known source which typically is the Earth tide. Consequently, the accuracy of the observed strain changes from borehole strainmeters depends upon the calibration derived from modeling the Earth tide. Previous work from the mid-1970s, which is replicated here, demonstrate that the theoretical tide can differ by 30% from the tide observed at surface-mounted, long-baseline strainmeters. In spite of possible inaccurate tidal models, many of the 74 borehole strainmeters installed since 2005 can be “calibrated”. However, inaccurate tidal models affect the amplitude and phase of observed transient strain changes which needs to be considered along with the precision of the data from the inherent drift of these borehole instruments. In particular, the error from inaccurate tidal model dominates the error budget in the observation of impulsive, sub-daily, strain-transients.

  19. Ocean tides and quasi-stationary departures from the marine geoid investigation

    NASA Technical Reports Server (NTRS)

    Siry, J. W.; Kahn, W. D.; Bryan, J. W.; Vonbun, F. O.

    1973-01-01

    The detection of tides and/or currents through the analysis of data generated in connection with the Ocean Geoid Determination Investigation is presented. A discussion of the detailed objectives and approach are included.

  20. Tide-related biological rhythm in the oxygen consumption rate of ghost shrimp (Neotrypaea uncinata).

    PubMed

    Leiva, Félix P; Niklitschek, Edwin J; Paschke, Kurt; Gebauer, Paulina; Urbina, Mauricio A

    2016-07-01

    The effects of tidal height (high and low), acclimation to laboratory conditions (days in captivity) and oxygen level (hypoxia and normoxia) were evaluated in the oxygen consumption rate (OCR) of the ghost shrimp Neotrypaea uncinata We evaluated the hypothesis that N. uncinata reduces its OCR during low tide and increases it during high tide, regardless of oxygen level or acclimation. Additionally, the existence of an endogenous rhythm in OCR was explored, and we examined whether it synchronized with tidal, diurnal or semidiurnal cycles. Unexpectedly, high OCRs were observed at low tide, during normoxia, in non-acclimated animals. Results from a second, longer experiment under normoxic conditions suggested the presence of a tide-related metabolic rhythm, a response pattern not yet demonstrated for a burrowing decapod. Although rhythms persisted for only 2 days after capture, their period of 12.8 h closely matched the semidiurnal tidal cycle that ghost shrimp confront inside their burrows. PMID:27099365