WorldWideScience

Sample records for aerosolized red tide

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

    OpenAIRE

    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 ...

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

    Science.gov (United States)

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

    2010-06-01

    Florida red tides occur annually in the Gulf of Mexico from blooms of the marine dinoflagellate, Karenia brevis, which produces highly potent natural polyether toxins, brevetoxins. Several epidemiologic studies have demonstrated that human exposure to red tide aerosol could result in increased respiratory symptoms. Environmental monitoring of aerosolized brevetoxins was performed using a high-volume sampler taken hourly at fixed locations on Siesta Beach, Florida. Personal exposure was monitored using personal air samplers and taking nasal swab samples from the subjects who were instructed to spend 1 hr on Sarasota Beach during two sampling periods of an active Florida red tide event in March 2005, and in May 2008 when there was no red tide. Results showed that the aerosolized brevetoxins from the personal sampler were in modest agreement with the environmental concentration taken from a high-volume sampler. Analysis of nasal swab samples for brevetoxins demonstrated 68% positive samples in the March 2005 sampling period when air concentrations of brevetoxins were between 50 to 120 ng/m(3) measured with the high-volume sampler. No swab samples showed detectable levels of brevetoxins in the May 2008 study, when all personal samples were below the limit of detection. However, there were no statistical correlations between the amounts of brevetoxins detected in the swab samples with either the environmental or personal concentration. Results showed that the personal sample might provide an estimate of individual exposure level. Nasal swab samples showed that brevetoxins indeed were inhaled and deposited in the nasal passage during the March 2005 red tide event. PMID:20379895

  3. Inland Transport of Aerosolized Florida Red Tide Toxins

    OpenAIRE

    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

    2010-01-01

    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 a...

  4. Inland Transport of Aerosolized Florida Red Tide Toxins.

    Science.gov (United States)

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

    OpenAIRE

    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...

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

    OpenAIRE

    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

    2004-01-01

    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 e...

  7. Occupational exposure to aerosolized brevetoxins during Florida red tide events: effects on a healthy worker population.

    Science.gov (United States)

    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

    2005-05-01

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

  8. Reported Respiratory Symptom Intensity in Asthmatics During Exposure to Aerosolized Florida Red Tide Toxins

    OpenAIRE

    Milian, Alexyz; Nierenberg, Kate; Fleming, Lora E.; Bean, Judy A.; Wanner, Adam; Reich, Andrew; Backer, Lorraine C.; Jayroe, David; Kirkpatrick, Barbara

    2007-01-01

    Florida red tides are naturally occurring blooms of the marine dinoflagellate, Karenia brevis. K. brevis produces natural toxins called brevetoxins. Brevetoxins become part of the marine aerosol as the fragile, unarmored cells are broken up by wave action. Inhalation of the aerosolized toxin results in upper and lower airway irritation. Symptoms of brevetoxin inhalation include: eye, nose, and throat irritation, coughing, wheezing, chest tightness, and shortness of breath. Asthmatics appear t...

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

    OpenAIRE

    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.

    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 tid...

  10. Initial evaluation of the effects of aerosolized Florida red tide toxins (brevetoxins) in persons with asthma.

    Science.gov (United States)

    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

    2005-05-01

    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

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

    Science.gov (United States)

    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.

  12. Reported respiratory symptom intensity in asthmatics during exposure to aerosolized Florida red tide toxins.

    Science.gov (United States)

    Milian, Alexyz; Nierenberg, Kate; Fleming, Lora E; Bean, Judy A; Wanner, Adam; Reich, Andrew; Backer, Lorraine C; Jayroe, David; Kirkpatrick, Barbara

    2007-09-01

    Florida red tides are naturally occurring blooms of the marine dinoflagellate, Karenia brevis. K. brevis produces natural toxins called brevetoxins. Brevetoxins become part of the marine aerosol as the fragile, unarmored cells are broken up by wave action. Inhalation of the aerosolized toxin results in upper and lower airway irritation. Symptoms of brevetoxin inhalation include: eye, nose, and throat irritation, coughing, wheezing, chest tightness, and shortness of breath. Asthmatics appear to be more sensitive to the effects of inhaled brevetoxin. This study examined data from 97 asthmatics exposed at the beach for 1 hour during K. brevis blooms, and on separate occasions when no bloom was present. In conjunction with extensive environmental monitoring, participants were evaluated utilizing questionnaires and pulmonary function testing before and after a 1-hour beach walk. A modified Likert scale was incorporated into the questionnaire to create respiratory symptom intensity scores for each individual pre- and post-beach walk. Exposure to Florida red tide significantly increased the reported intensity of respiratory symptoms; no significant changes were seen during an unexposed period. This is the first study to examine the intensity of reported respiratory symptoms in asthmatics after a 1-hour exposure to Florida red tide. PMID:17885863

  13. Correlations between atmospheric aerosol trace element concentrations and red tide at Port Aransas, Texas, on the Gulf of Mexico

    International Nuclear Information System (INIS)

    Neutron activation analysis (NAA) was employed as an analytical technique to measure atmospheric aerosol concentrations of trace metals in Port Aransas, TX on the Gulf of Mexico. The sources of atmospheric aerosols and the seasonal variation of the sources are explored. High atmospheric iron concentrations are then shown to have a possible correlation to the occurrences of red tide in this region. The data shows that this correlation is plausible, but due to the many factors that affect red tide growth a definitive conclusion may not be reached. The period of study for these measurements was September 12, 2000 to January 4, 2002. (author)

  14. Red Tide off Texas Coast

    Science.gov (United States)

    2002-01-01

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

  15. Public Perceptions of Florida Red Tide Risks

    OpenAIRE

    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 ...

  16. Public perceptions of Florida red tide risks.

    Science.gov (United States)

    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

  17. Brevetoxicosis: red tides and marine mammal mortalities.

    Science.gov (United States)

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

    2005-06-01

    Potent marine neurotoxins known as brevetoxins are produced by the 'red tide' dinoflagellate Karenia brevis. They kill large numbers of fish and cause illness in humans who ingest toxic filter-feeding shellfish or inhale toxic aerosols. The toxins are also suspected of having been involved in events in which many manatees and dolphins died, but this has usually not been verified owing to limited confirmation of toxin exposure, unexplained intoxication mechanisms and complicating pathologies. Here we show that fish and seagrass can accumulate high concentrations of brevetoxins and that these have acted as toxin vectors during recent deaths of dolphins and manatees, respectively. Our results challenge claims that the deleterious effects of a brevetoxin on fish (ichthyotoxicity) preclude its accumulation in live fish, and they reveal a new vector mechanism for brevetoxin spread through food webs that poses a threat to upper trophic levels. PMID:15944690

  18. Concentration and Particle Size of Airborne Toxic Algae (Brevetoxin) Derived from Ocean Red Tide Events

    OpenAIRE

    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.

    2005-01-01

    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....

  19. Florida Red Tide Perception: Residents versus Tourists.

    Science.gov (United States)

    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. NOAA NCCOS: New England Red Tide Research

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Alexandrium blooms are one of several algal bloom types often called "red tides," but more correctly referred to as Harmful Algal Blooms (HABs). Alexandrium...

  1. Red Tide Frequency Analysis Using the Extreme Value Theory

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    In recent years, the red tide erupted frequently, and caused a great economic loss. At present, most literatures emphasize the academic research on the growth mechanism of red tide alga. In order to find out the characters of red tide in detail and improve the precision of forecast, this paper gives some new approaches to dealing with the red tide. By the extreme values, we deal with the red tide frequency analysis and get the estimation of T-times red tide level U(T), which is the level once the consistence of red tide alga exceeds on the average in a period of T times.

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

    OpenAIRE

    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

    2011-01-01

    Having demonstrated significant and persistent adverse changes in pulmonary function for asthmatics after 1 hour exposure to brevetoxins in Florida red tide (Karenia brevis bloom) aerosols, we assessed the possible longer term health effects in asthmatics from intermittent environmental exposure to brevetoxins over 7 years. 125 asthmatic subjects were assessed for their pulmonary function and reported symptoms before and after 1 hour of environmental exposure to Florida red tide aerosols for ...

  3. Late Devonian red tide and mass extinction

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Molecular stratigraphical, carbonate carbon isotopic, stratigraphical and paleontological data show that algal booming, eutrophication, anoxia, hypersalinity, positive ( 13C excursion and biomass decreasing occurred in the offshore carbonate environments of the Frasnian-Famennian (F-F) transition, which hints that red tide might frequently take place in the F-F transition of Guangxi, South China. We suggest that the mass extinction of the reef ecosystems and the shallow-water marine organisms in the F-F transition of the lower-middle latitudes may be related to the frequent occurrence of red tide in that time.

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

    Science.gov (United States)

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

    2006-10-01

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

  5. Population dynamics of red tide dinoflagellates

    Science.gov (United States)

    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.

  6. Prediction Research of Red Tide Based on Improved FCM

    OpenAIRE

    Xiaomei Hu; Dong Wang; Hewei Qu; Xinran Shi

    2016-01-01

    Red tides are caused by the combination effects of many marine elements. The complexity of the marine ecosystem makes it hard to find the relationship between marine elements and red tides. The algorithm of fuzzy c-means (FCM) can get clear classification of things and expresses the fuzzy state among different things. Therefore, a prediction algorithm of red tide based on improved FCM is proposed. In order to overcome the defect of FCM which is overdependent on the initial cluster centers and...

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

    OpenAIRE

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

    1990-01-01

    Vibrios were isolated from red tides caused by Mesodinium rubrum and also throughout the year in the Ria de Pontevedra, Spain. The isolates were grouped into 14 phena by numerical toxonomy. Strains associated with red tides were restricted to four phena: phena I and II were Vibrio alginolyticus, and phena III and IV were Vibrio tubiashii and Vibrio anguillarum, respectively. V. anguillarum-like strains (phena V through XI) predominated throughout the year outside the red tide areas. Cytotoxic...

  8. Red Tide Strands South African Rock Lobsters

    Science.gov (United States)

    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 Tides in Nagasaki Bay during Summer Season of 1979

    OpenAIRE

    Dahril, Tengku; Iizuka, Shoji

    1981-01-01

    Almost every year during the summer season, red tides have occurred in Nagasaki Bay. Red tides are caused by various kind of phytoplankton and bay waters discolor like coffee by the exclusive growth of a single organism or mixed growth of two or three organisms. However, very little is known about red tide in this bay. In this paper the authors dealt with red tides in Nagasaki Bay during the summer season of 1979. The innermost part of this bay was divided into 3 areas. Five water sampling st...

  10. Prediction Research of Red Tide Based on Improved FCM

    Directory of Open Access Journals (Sweden)

    Xiaomei Hu

    2016-01-01

    Full Text Available Red tides are caused by the combination effects of many marine elements. The complexity of the marine ecosystem makes it hard to find the relationship between marine elements and red tides. The algorithm of fuzzy c-means (FCM can get clear classification of things and expresses the fuzzy state among different things. Therefore, a prediction algorithm of red tide based on improved FCM is proposed. In order to overcome the defect of FCM which is overdependent on the initial cluster centers and the objective function, this paper gains the initial cluster centers through the principle of regional minimum data density and the minimum mean distance. The feature weighted cluster center is added to the objective function. Finally, the improved FCM algorithm is applied in the prediction research of red tide, and the results show that the improved FCM algorithm has good denoising ability and high accuracy in the prediction of red tides.

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

    OpenAIRE

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

    2006-01-01

    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 ...

  12. Studies offer insight into the formative mechanism of "red tides"

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Harmful algal blooms (HABs) in coastal waters, popularly known as "red tides" in China, have become a serious marine environmental problem and an ecological disaster, arousing grave concern of governments, the public and scientists worldwide.

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

    OpenAIRE

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

    2004-01-01

    In 1996, 149 Florida manatees, Trichechus manatus latirostris, died along the southwest coast of Florida. Necropsy pathology results of these animals indicated that brevetoxin from the Florida red tide, Karenia brevis, caused their death. A red tide bloom had been previously documented in the area where these animals stranded. The necropsy data suggested the mortality occurred from chronic inhalation and/or ingestion. Inhalation theories include high doses of brevetoxin deposited/stored in th...

  14. Review of Florida Red Tide and Human Health Effects

    OpenAIRE

    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

    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 resea...

  15. Inorganic carbon acquisition in red tide dinoflagellates.

    Science.gov (United States)

    Rost, Björn; Richter, Klaus-Uwe; Riebesell, Ulf; Hansen, Per Juel

    2006-05-01

    Carbon acquisition was investigated in three marine bloom-forming dinollagellates-Prorocentrum minimum, Heterocapsa triquetra and Ceratium lineatum. In vivo activities of extracellular and intracellular carbonic anhydrase (CA), photosynthetic O2 evolution, CO2 and HCO3- uptake rates were measured by membrane inlet mass spectrometry (MIMS) in cells acclimated to low pH (8.0) and high pH (8.5 or 9.1). A second approach used short-term 14C-disequilibrium incubations to estimate the carbon source utilized by the cells. All three species showed negligible extracellular CA (eCA) activity in cells acclimated to low pH and only slightly higher activity when acclimated to high pH. Intracellular CA (iCA) activity was present in all three species, but it increased only in P. minimum with increasing pH. Half-saturation concentrations (K1/2) for photosynthetic O2 evolution were low compared to ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) kinetics. Moreover, apparent affinities for inorganic carbon (Ci) increased with increasing pH in the acclimation, indicating the operation of an efficient CO2 concentration mechanism (CCM) in these dinoflagellates. Rates of CO2 uptake were comparably low and could not support the observed rates of photosynthesis. Consequently, rates of HCO3- uptake were high in the investigated species, contributing more than 80% of the photosynthetic carbon fixation. The affinity for HCO3- and maximum uptake rates increased under higher pH. The strong preference for HCO3- was also confirmed by the 14C-disequilibrium technique. Modes of carbon acquisition were consistent with the 13C-fractionation pattern observed and indicated a strong species-specific difference in leakage. These results suggest that photosynthesis in marine dinoflagellates is not limited by Ci even at high pH, which may occur during red tides in coastal waters. PMID:17087465

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

  19. NUMERICAL SIMULATION OF 1998 RED TIDE OF THE BOHAI SEA

    Institute of Scientific and Technical Information of China (English)

    Yongsheng WU; Zhao-Yin WANG

    2002-01-01

    Algal bloom,known as red tide,has occurred frequently in the Bohai Sea in recent decades causing great economic losses to fisheries as well as having significant adverse impact on the environment. A 3-D Eco-Hydraulic model is developed to simulate the explosive propagation of diatom and dinoflagellate as a function of the concentration of various nutrients,river inflow,tide,temperature,wind,sunshine and rainfall. The model is intended to answer the questions ofhow the 1998 Bohai Sea red tide occurred,and to investigate how environmental factors,such as temperature,wind,rainfall,solar radiance,sea currents and nutrients,affect the algal bloom process. The parameters employed in the model are calibrated with the data collected in the periods 1982-1983 and 1992-1993. Results from the model indicate that eutrophication of the seawater is the basic condition for algal bloom,and that the 1998 red tide was triggered by the abnormal warm weather in August and September.

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

    Institute of Scientific and Technical Information of China (English)

    ZHAO Wencang; WEI Hongli; SHI Changjiang; JI Guangrong

    2008-01-01

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

  1. STUDY OF RED TIDE PREDICTION MODEL FOR THE CHANGJIANG ESTUARY

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper based on field data (on red tide water quality monitoring at the Changjiang 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.

  2. A real time measurement system for red tide studies

    OpenAIRE

    Lam, HYI; Hodgkiss, IJ

    2001-01-01

    An apparently increasing trend of red tide occurrences and/or harmful algal blooms has become a global issue, particularly in coastal zones with 'cultural eutrophication', but no effective measures have been developed yet for detection and early warning, in order to prevent public health problems and the threat of economic losses. A multiple-probe-and-sensor based telemetry system has been developed to monitor water quality parameters, hydrographic variables and meteorological conditions, in ...

  3. Environmental Forcing of Red Tides in the Southern Benguela

    OpenAIRE

    Mark R. Jury

    2014-01-01

    The Southern Benguela cape upwelling plumes have inshore wind shadows prone to red tides in late summer. Their intensity and coverage are estimated by satellite fluorescence measurements in the period 1997–2012 and qualified by in situ reports. High satellite fluorescence cases are identified at daily to seasonal time scales, and characteristics of the upper ocean and lower atmosphere are studied using third generation reanalyses. A dominant feature is easterly winds over the Cape Peninsula (...

  4. The Fundamental Experiments of Red Tide Chemical Forecast

    Institute of Scientific and Technical Information of China (English)

    Zhang ZhengBin; Liu Chunying; Li Peifeng; Wu Zhenzhen; Lin Cai; Huang Huawei; Xing Lei; Liu Liansheng

    2006-01-01

    Many food algae and red tide algae were cultivated in the f/2 medium,and the nitric oxide(NO)concentration of the medium and the cell density were determined.The experiments on algae were conducted when different concentrations of NO were added into the medium using two methods.The results show that low concentrations of NO were self-produced by marine algae during the exponential growth period and were about nmol/L level.But at the end of the period,i.e.,2 or 3 days before the cell density reaches the maximum,an NO peak appeared,with the NO concentration reaching 10 umol/L.The NO threshold concentration exists according to the influence of exogenous NO on the marine phytoplankton growth.One type is the threshold concentration that can promote algae growth,and its value is between 10 and 1 nmol level,or even lower.The other type can inhibit the phytoplankton growth,which is about μmol level or higher.The results indicate that red tide algae are far more sensitive to NO than are food algae.The fundamental experimental outcome above may provide a new clue for red tide chemical forecast by inspecting the NO change.

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

    Science.gov (United States)

    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 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.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

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

    2005-01-01

    An exceptional red tide in San Francisco Bay was observed on 8 September 2004. The red tide had chlorophyll concentrations approaching 200 mg/m3 (Figure 1) in red/purple surface streaks containing high abundances of the dinoflagellate Akashiwo sanguinea. Red tides and harmful algal blooms (HABs) are common features of coastal ecosystems, and their growing frequency is a suspected outcome of coastal eutrophication.

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

    Science.gov (United States)

    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

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

    OpenAIRE

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

    2010-01-01

    The marine dinoflagellate, Karenia brevis, is responsible for Florida red tides. Brevetoxins, the neurotoxins produced by K. brevis blooms, can cause fish kills, contaminate shellfish, and lead to respiratory illness in humans. Although several studies have assessed different economic impacts from Florida red tide blooms, no studies to date have considered the impact on beach lifeguard work performance. Sarasota County experiences frequent Florida red tides and staffs lifeguards at its beache...

  10. Red Tide Observations along the Eastern Black Sea Coast of Turkey

    OpenAIRE

    FEYZİOĞLU, Ali Muzaffer; ÖĞÜT, Hamdi

    2006-01-01

    To determine the occurrence of dominant phytoplanktonic species causing red tides along the eastern Black Sea (Trabzon) coast of Turkey, multiple samples were collected periodically between 1991 and 2001. Red tide events were observed only during the periods between February and July. Six phytoplanktonic species causing 5 red tide events detected were Diplopsalis lenticula, Euglena acusformis, Eutreptia lanowii, Pyramimonas orientalis, Scrippsiella trochoidea, and Gymnodinium sanguineum. Nume...

  11. EUTROPHICATION AND RED TIDES AS CONSEQUENCES OF ECONOMIC DEVELOPMENT

    Institute of Scientific and Technical Information of China (English)

    ZhaoYin WANG; Yongsheng WU; Guangqian WANG

    2001-01-01

    This paper reports the phenomena of eutrophication and red tides correlated with human activities,especially economic development. The fertilizer production in China has been accelerated since the 1970s and has approximately doubled the rate of nitrogen input into the terrestrial N cycle. While the rate of the total population growth of China maintains relatively stable the rate of population growth in cities and towns in the 1980s and 1990s was 10 times higher than ever before. As a result, the urban sewage discharge increased by 400%, which carries 1 million tons of nitrogen into the environmental waters per year. The mining of P minerals and application of P-containing fertilizers greatly enhanced the input of P into the waters. Harmful algal blooms are consequence of the eutrophication. The high frequency of algal bloom is related to the quick economic development since the 1970s and the eutrophication of environmental waters. Analysis indicates that the number of the red tide events in the China Seas roughly follows the curve of the growth rate of GDP with a time lag of about 5-6 years. The time lag is explained as the period of the cycle of accumulation, denitrification and release of the nutrients with transportation and resuspension of the sediment.

  12. Environmental Forcing of Red Tides in the Southern Benguela

    Directory of Open Access Journals (Sweden)

    Mark R. Jury

    2014-01-01

    Full Text Available The Southern Benguela cape upwelling plumes have inshore wind shadows prone to red tides in late summer. Their intensity and coverage are estimated by satellite fluorescence measurements in the period 1997–2012 and qualified by in situ reports. High satellite fluorescence cases are identified at daily to seasonal time scales, and characteristics of the upper ocean and lower atmosphere are studied using third generation reanalyses. A dominant feature is easterly winds over the Cape Peninsula (34°S, 18°E induced by a ridging anticyclone-coastal low weather pattern. Over Cape Columbine (33°S, there is a wind shadow with cyclonic wind and current shear. Composite atmospheric profiles reveal a 4°C temperature inversion near 500 m that traps a coastal wind jet >6 m/s below 200 m. The composite shelf oceanography shows a relic upwelling plume below 10 m overtopped by warmer water near the coast, providing the thermal stratification needed for biotic aggregation. Data from the IPSL5 coupled climate model over the period 1980–2080 indicates that environmental conditions favoring red tides may become more frequent.

  13. RESEARCH ON RED TIDE OCCURRENCES USING ENCLOSED EXPERIMENTAL ECOSYSTEMS IN WEST XIAMEN HARBOR, CHINA--RELATIONSHIP BETWEEN VARIOUS FACTORS AND RED TIDE OCCURRENCES

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

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

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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…

  16. A new algorithm based on the background field for red tide monitoring in the East China Sea

    Institute of Scientific and Technical Information of China (English)

    XU Xiaohui; PAN Delu; MAO Zhihua; TAO Bangyi

    2014-01-01

    Remote sensing has been proven to be an effective means of monitoring red tides. The spectral information is an important basis for establishing a model to monitor red tides. The spectral curves of red tide events are analyzed and compared with multiyear monthly averaged spectral curves based on MODIS data from July 2002 to June 2012, as well as spectral differences at the same location during red tide presence and ab-sence. A red tide monitoring algorithm is developed based on the background field to extract the red tide information of the East China Sea (ECS). With the application of the algorithm in the ECS, the results reveal that the developed model can effectively determine the location of red tides, with good correspondence to the results from an official bulletin. This demonstrates that the algorithm can effectively extract the red tide information.

  17. Maltivariate Analysis of the Occurring Process of Skeletonema costatum Red Tide in the Changjiang Estuary

    Institute of Scientific and Technical Information of China (English)

    黄秀清; 蒋晓山; 陶然; 洪君超

    2001-01-01

    Using the SAS software, the data of environmental factors vs. red tide biomass were analysed during the process of Skeletonema costatum red tide which broke out in the Changjiang Estuary on June 9~15, 1990. The results of the multivariate statistical analysis show that the environmental factors are similar in their developing and maintenance periods and that the values of environmental factors begin to be restored to normal levels during the disappearing period.The results obtained from using the methods of correlation, variable cluster and main component analyses are basically identical. The important factors contributing to the occurrence of this red tide are atmospherical pressure, water temperature, salinity, pH, No3-, -N, Po43--P and Fe, among which,salinity, Fe and PO43--P are the leading factors which have triggered the occurrence of the red tide as determined by the step-by-step regression analysis. Meanwhile, the linear discrimination functions have been established for the red tide. The environmental factor data of another occurring process of Skeletonema costatum red tide in the Changjiang Estuary have been chosen for red tide discrimination with satisfactory results.

  18. A relationship between red tide outbreaks and urban development along the coasts of Guangdong Province

    Institute of Scientific and Technical Information of China (English)

    LIUXiaonan; WANGWei

    2004-01-01

    Red tides are one of the main coastal catastrophic events in Guangdong Province of southern China. The comparison between the number of red tide events and the development indexes of cities along the coasts of the province shows that the regional differences in red tide outbreaks has close relations with the coastal urban developments. The cause for an initiation of red tide blooms may be natural factors, while wastewater caused by the fast development of population, industry and aquiculture of the coastal cities enhanced the blooms. It may explain why the two periods of frequent outbreaks of the red tides over the last two decades matched the urban developments in the coastal areas of Guangdong not only spatially but also temporally. The red tides in the first period were restricted only to the coasts of middle Guangdong, where urbanization process was at a higher speed than the other coastal areas of the province. In the second period, fast development of the coastal cities in eastern Guangdong led to an increase in the occurrence of red tides in local sea areas of the same coasts.

  19. The Monitoring of Red Tides Based on Modular Neural Networks Using Airborne Hyperspectral Remote Sensing

    Institute of Scientific and Technical Information of China (English)

    JI Guangrong; SUN Jie; ZHAO Wencang; ZHANG Hande

    2006-01-01

    This paper proposes a red tide monitoring method based on clustering and modular neural networks. To obtain the features of red tide from a mass of aerial remote sensing hyperspectral data, first the Log Residual Correction (LRC) is used to normalize the data, and then clustering analysis is adopted to select and form the training samples for the neural networks. For rapid monitoring, the discriminator is composed of modular neural networks, whose structure and learning parameters are determined by an Adaptive Genetic Algorithm (AGA). The experiments showed that this method can monitor red tide rapidly and effectively.

  20. RESEARCH ON RED TIDE OCCURRENCES USING ENCLOSED EXPERIMENTAL ECOSYSTEM IN WEST XIAMEN HARBOR, CHINA RELATIONSHIP BETWEEN NUTRIENTS AND RED TIDE OCCURRENCE

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    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.

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

    Science.gov (United States)

    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.

  2. Severe fish mortality associated with 'red tide' observed in the sea off Cochin

    Digital Repository Service at National Institute of Oceanography (India)

    Naqvi, S.W.A; George, M.D.; Narvekar, P.V.; Jayakumar, D.A; Shailaja, M.S.; Sardessai, S.; Sarma, V.V.S.S.; Shenoy, D.M.; Naik, H.; Maheswaran, P.A; KrishnaKumari, L.; Rajesh, G.; Sudhir, A; Binu, M.S.

    Severe fish mortality associated with the "red tide" phenomenon caused by Noctiluca blooms was observed in the sea off Cochin, Kerala, India at depths less than 40 m. The dead fish, almost entirely comprised of the threadfin bream (Nemipterus...

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

    OpenAIRE

    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.

    2004-01-01

    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 s...

  4. Persistent whole-bay red tide of Noctiluca scintillans in Manila Bay, Philippines

    OpenAIRE

    Furuya, Ken; Saito, Haruna; Rujinard, Sriwoon; Anil K. Vijayan; Omura, Takuo; Elsa E. Furio; Valeriano M. Borja; Sopana, Boonyapiwat; Thaithaworn, Lirdwitayaprasit

    2006-01-01

    Noctiluca scintillans, which contains a photosynthetic endosymbiont, Pedinomonas noctilucae, formed perennial red tides in Manila Bay, Philippines, occasionally covering almost whole area since 2001. A whole-bay scale red tide of the green Noctiluca in Manila Bay is described as the first step to elucidate the formation mechanism of the large scale blooming of the organism. A field survey was conducted in March 2004, when greenish discoloration due to N. scintillans was observed in the whole ...

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

    OpenAIRE

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

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

    Science.gov (United States)

    Hayashi, Mitsuru; Yanagi, Tetsuo

    2008-01-01

    Occurrence number of red tides in Osaka Bay in Japan is more than 20 cases every year. Diatom red tide was dominant in Osaka Bay, but the non-diatom red tide was dominant in early 1990s. Therefore, the material cycling in Yodo River estuary in Osaka Bay during August from 1991 to 2000 was analyzed by using the numerical ecosystem model and field observation data to clarify the reasons of change in red tide species. Year-to-year variation in calculated concentration ratio of diatom to non-diatom corresponds to the variation in observed ratio of red tide days of diatom to non-diatom. Limiting nutrient of primary production is phosphate over the period. Diatom dominated from 1991 to 1993, but it was difficult for non-diatom to grow due to the limitation by physical condition. Non-diatom was able to grow because of good physical and nutrient conditions from 1994 to 1996. And diatom dominated again under the good physical condition, and phosphorus supply was not enough for non-diatom to grow from 1998 to 2000. Phosphate concentration in the lower layer of Yodo River estuary was important to the variation in red tide species in the upper layer of Yodo River estuary. PMID:18513758

  7. Study of freshwater red tide control measures; Tansui akashio taisaku ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Onishi, M.; Hatamochi, K. [Kansai Electric Power Co. Inc., Osaka (Japan)

    1997-09-30

    Basic research of biological measures for which the accumulation of basic findings is mandatory and the applied research of chemical and physical measures that are higher in feasibility are conducted for the establishment of measures to counter freshwater red tides. In the basic research, natural enemies, algaecidal microbes, conjugation inhibiting substances, and allelopathy are studied, but none of them is found feasible at the current stage. In the basic research, however, factors are discovered that inhibit the multiplication of Peridinium bipes or perish the same. In the applied research, chemical algaecidal methods, UV-aided algaecidal methods, and various red-tide constituent collection methods are studied. Collection methods are compared, and it is concluded that a method of Toray Industries, Inc., efficiently collects red-tide constituents. In this method, red-tide constituents are screened by and condensed on a cloth filter provided on the internal wall of a drum, and are dehydrated and then transferred. The applied research further involves the prediction of red tide outbreak and the raising of fish on a food containing substances extracted from red tides, and it is suggested that these are feasible. 18 refs., 15 figs., 3 tabs.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

  10. Comparative Study on Discrimination Methods for Identifying Dangerous Red Tide Species Based on Wavelet Utilized Classification Methods

    Directory of Open Access Journals (Sweden)

    Kohei Arai

    2013-02-01

    Full Text Available Comparative study on discrimination methods for identifying dangerous red tide species based on wavelet utilized classification methods is conducted. Through experiments, it is found that classification performance with the proposed wavelet derived shape information extracted from the microscopic view of the phytoplankton is effective for identifying dangerous red tide species among the other red tide species rather than the other conventional texture, color information.

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    David A Jessup

    Full Text Available 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.

  13. Red Tide Information Extraction Based on Multi-source Remote Sensing Data in Haizhou Bay

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Objective] The aim was to extract red tide information in Haizhou Bay on the basis of multi-source remote sensing data.[Method] Red tide in Haizhou Bay was studied based on multi-source remote sensing data,such as IRS-P6 data on October 8,2005,Landsat 5-TM data on May 20,2006,MODIS 1B data on October 6,2006 and HY-1B second-grade data on April 22,2009,which were firstly preprocessed through geometric correction,atmospheric correction,image resizing and so on.At the same time,the synchronous environment mon...

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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...

  16. A Semianalytical Model Using MODIS Data to Estimate Cell Density of Red Tide Algae (Aureococcus anophagefferens

    Directory of Open Access Journals (Sweden)

    Lingling Jiang

    2016-01-01

    Full Text Available A multiband and a single-band semianalytical model were developed to predict algae cell density distribution. The models were based on cell density (N dependent parameterizations of the spectral backscattering coefficients, bb(λ, obtained from in situ measurements. There was a strong relationship between bb(λ and N, with a minimum regression coefficient of 0.97 at 488 nm and a maximum value of 0.98 at other bands. The cell density calculated by the multiband inversion model was similar to the field measurements of the coastal waters (the average relative error was only 8.9%, but it could not accurately discern the red tide from mixed pixels, and this led to overestimation of the area affected by the red tide. While the single-band inversion model is less precise than the former model in the high chlorophyll water, it could eliminate the impact of the suspended sediments and make more accurate estimates of the red tide area. We concluded that the two models both have advantages and disadvantages; these methods lay the foundation for developing a remote sensing forecasting system for red tides.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

  19. Allelopathic interactions between the red-tide causative dinoflagellate Prorocentrum donghaiense and the diatom Phaeodactylum tricornutum

    Directory of Open Access Journals (Sweden)

    Zhuoping Cai

    2014-06-01

    Full Text Available The interactions between the red-tide causing dinoflagellate Prorocentrum donghaiense and the marine diatom Phaeodactylum tricornutum were investigated using a co-culture experiment and an enriched culture filtrate experiment. The results showed that when the two microalgae were cultured together with different initial cell densities, the growth of one species was basically suppressed by the other one. In addition, the enriched culture filtrates of one species had generally inhibitory effects on the other one. Our result inferred that P. donghaiense and P. tricornutum would interfere with each other mainly by releasing allelochemicals into the culture medium, and that the degree of allelopathic effects was dependent on the initial cell densities and growth phases. The allelopathic interactions between microalgal species may contribute to the formation and succession of red tides.

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

    Science.gov (United States)

    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

    [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

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

    OpenAIRE

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

    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 coll...

  2. Contributions to the Understanding of the Bloom Dynamics of Pyrodinium bahamense var. compressum: A Toxic Red Tide Causative Organism

    Directory of Open Access Journals (Sweden)

    Rhodora Azanza

    1997-12-01

    Full Text Available Pyrodinium bahamense var. compressum has been the primary organism responsible for the toxic red tide episodes which have been recurring in Manila Bay, Philippines since 1988. The life history of the species has been elucidated through encystment-excystment studies in vitro, from which its obligatory dormancy has been demonstrated. Cyst-mapping studies have shown that this life stage of the organism occurs relatively higher in the Bataan and Cavite areas where the greater number of red tide occurrences have also been reported. A cyst-based model has been developed as an initial step in understanding the role of physical processes in the development, occurrence/recurrence, and ultimately, advancement of Pyrodinium red tides in Manila Bay.To help mitigate or prevent the negative impacts of toxic red tides, particularly in Manila Bay, regular closure of shellfish harvest in areas affected by Pyrodinium bloom should be considered, based on long term monitoring and research data sets.

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

    Science.gov (United States)

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

    2009-11-01

    We examined the survival rate of Cochlodinium polykrikoides after yellow loess addition and conducted culture experiments to investigate the possibility that red tides maybe caused by C. polykrikoides individuals that are precipitated when loess is added. At least 15% of the C. polykrikoides cells that precipitated to the bottom layer either by the addition of loess or no addition survived for 1 week at all growth phases, rather than disappearing immediately after precipitating. However no live cells were observed after 20 days, regardless of phase or loess addition. In the exponential phase, the number of C. polykrikoides cells increased to >2886 cells ml(-1) after loess was added. However in the stationary phase, the number of cells did not increase until 18 days. In the exponential phase, those C. polykrikoides that survived precipitation caused by scattering loess on cultures did not appear to have the ability to cause red tides again because of the short red tide periods in the field, long lag time after loess addition, and low survival rate after loess addition. PMID:20329384

  4. 赤潮研究现状与动向%State and Prospect of Red Tide Research

    Institute of Scientific and Technical Information of China (English)

    李桂娇; 尹华; 彭辉

    2001-01-01

    This paper summarized the state of red tide research,analyzed thecause and hazard,summed up the prevention and treatment,and monitoring techniques.It also prospected the trend of red tide research.%综述了赤潮研究现状,分析了发生原因、危害,总结了防治措施、监测预报技术,展望了今后的研究动向。

  5. Contributions to the Understanding of the Bloom Dynamics of Pyrodinium bahamense var. compressum: A Toxic Red Tide Causative Organism

    OpenAIRE

    Rhodora Azanza

    1997-01-01

    Pyrodinium bahamense var. compressum has been the primary organism responsible for the toxic red tide episodes which have been recurring in Manila Bay, Philippines since 1988. The life history of the species has been elucidated through encystment-excystment studies in vitro, from which its obligatory dormancy has been demonstrated. Cyst-mapping studies have shown that this life stage of the organism occurs relatively higher in the Bataan and Cavite areas where the greater number of red tide o...

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

    Science.gov (United States)

    Lee, Young Sik

    2006-10-01

    Red tides caused by the dinoflagellate Cochlodinium polykrikoides occur annually in coastal waters of Korea, causing significant damage. A distinguishing characteristic of C. polykrikoides red tides is that they develop and persist in the open sea, where the water is comparatively clean with little contamination from the shore. We examined the causes of and key nutrients involved in high-density C. polykrikoides red tide outbreaks in the coastal seawaters around Yeosu and Tongyeong, Korea. High-density C. polykrikoides red tides occur in the coastal areas of Geomo Island, where freshwater flows into the sea after heavy rainfall events. Red tides are widespread in years when rainfall is heavy. The maximum concentration of C. polykrikoides and the duration of the red tides increase with increasing rainfall. Adding nitrogen and Seomjin River water to cultures of C. polykrikoides also increases biomass production and cell density of C. polykrikoides remarkably increased after heavy rainfall events. The occurrence of high concentrations of C. polykrikoides along the shores of Yeosu and Tongyeong seems to result from rainfall-initiated inflows of high concentrations of nitrate secondarily, after a conducive physical and chemical open-water environment has been established for C. polykrikoides to spread initially. PMID:16631809

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

    Science.gov (United States)

    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.

  8. Study on the Characteristic Organic Compounds in Red Tide by Factor Analysis Method

    Institute of Scientific and Technical Information of China (English)

    赵明桥; 李攻科; 张展霞

    2004-01-01

    Factor analysis is used to study the organic compounds that have high degree of correlation with biomass in algal blooming. Based on this correlation, they are named characteristic organic compounds. The compounds found are sequalene (SQU), cedrol (CED), 2, 5-cyclohexadiene-1, 4-dione, 2, 6-bis(1, 1-dimthylethyl )(PBQ), phenol, 2, 6-bis (1, 1-dimethylethy-4-methyl) (BHT), 3-t-butyl-4-hydroxyanisole ( BHA ), 1, 2-benzenedicarboxylie acid, bis-( 2-methyl propyl ) ester (DIBP), dibutyl phthalate (DNBP), respectively. Monitoring the variations of concentration of these characteristic organic compounds in seawater may provide scientific basis for studying and forecasting red tides.

  9. Studies on Biquaternary Ammonium Salt Algaecide for Removing Red Tide Algae

    Institute of Scientific and Technical Information of China (English)

    刘洁生; 张珩; 杨维东; 高洁; 柯琼

    2004-01-01

    The paper deals with the removal and control of red tide algae, Phaeoecystis globosa and Alexandrium tamarense by biquaternary ammonium salt algaecide. The results show that the efficient concentration of biquaternary ammonium salt to control the two algaes in 96 h is 0.8 mg · L-1 and 0.4 mg · L-1, respectively. It is found that biquaternary ammonium salt has high efficiency and longer duration of action in the removal and control of algae.Biquaternary ammonium salt might be an excellent algaecide to control HAB.

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

    Science.gov (United States)

    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

  11. Nutrient and chlorophyll a anomaly in red-tide periods of 2003-2008 in Sishili Bay, China

    Institute of Scientific and Technical Information of China (English)

    HAO Yanju; TANG Danling; YU Long; XING Qianguo

    2011-01-01

    Sishili Bay is the most important aquiculture and tourism area for the city of Yantai, China; however, red tides occurred frequently and have caused huge economic losses in this bay in recent years. To gain a better understanding of the local ecological environments in the bay, we conducted this research between 2003 and 2008 to analyze variations in nutrients and chlorophyll (chl-α) during high frequency red tide period (May to September). The results show that the chl-α concentration increased from 2.70 in 2003 to 7.26 mg/m3 in 2008, while the concentration of total inorganic nitrogen (TIN) and silicate (SiO3-Si) increased lineally from 5.18 and 1.45μmol/L in 2003 to 18.57 and 9.52 μmol/L in 2008, respectively, and the annual phosphate (PO4-P) varied between 0.15 and 0.46 μmol/L. Special attention was given to a red tide in August 2007 occurred when water temperature was high and nutrient concentrations increased sharply because of a heavy rainfall. Overall, the results show the P limitation in Sishili Bay, and reveal that red tides were caused by eutrophication from terrestrial inputs and local warm weather, particularly during rainy periods. Therefore, to control red tide, greater efforts should be made to reduce sewage discharges into Sishili Bay, particularly during rainfall seasons.

  12. Allelopathic inhibition on red tide microalgae Skeletonema costatum by five macroalgal extracts

    Institute of Scientific and Technical Information of China (English)

    Zhen AN; Zhenyu WANG; Fengmin LI; Zhijia TIAN; Hongying HU

    2008-01-01

    This study aims to identify effective antialgal allelochemicals from marine macroalgae that inhibit the growth of red tide-,microalgae. Practically, new algicidal agents were developed to control red tide. The growth inhibitory effects of 5 marinemacroalgae Porphyra tenera, Laminaria japonica, Ulva pertusa, Enteromorpha cla- thrata, and Undaria pinnatifida on Skeletonema costatum were evaluated by adding crude seawater extracts of macroalgal dry tissue into the culture medium containing S. costatum. The half-effective concentrations at 120 h (EC50, 120h) of the seawater extracts were 0.6, 0.9, 1.0, 1.0, and 4.7 g/L for the five macroalgae above, respect-ively. E. clathrata, L. japonica and U. pertusa showed strong allelopathic effect on the growth of S. costatum. There have been no previous reports with regard to the allelopathic effects of the former two macroalgae so far. The possible allelochemicals of 21 compounds of the E. clathrata were detected using Gas chromatography-mass spectrometry (GC-MS) analysis. Unsaturated fatty acids, acrylic acid (C3H4O2), and linolenic acid (C18H30O2) were the most likely allelochemicals in E. clathrata.

  13. The prewarning value of Alexandrium tamarense PSP in an area with frequent outburst of red tide

    Institute of Scientific and Technical Information of China (English)

    JI Weidong; HUANG Deqiang; LI Yang; ZHOU Qiulin; HUO Wenmian; CHEN Weifen; LIN Hui; HE Qing; CHEN Baohong; LIANG Junrong; GAO Yahui

    2007-01-01

    The PSP toxicity of Alexandrium tamarense (Lebour) Balech on the blue mussel (Mytilus edulis) from the western waters of Xiamen in China was studied by following the standard method of PSP mouse bioassay developed by the Association of Official Analytical Chemists (AOAC). The results showed that the mice survived when the density of A. tamarense cells was lower than 1×105 cells per cubic decimetre and died when the density was higher than 1×106 cells per cubic decimetre. The past record of red tide events in the western waters of Xiamen showed a general trend of starting from the bloom of non-toxic planktonic diatoms in local waters and resulting in a harmful algal bloom due to the fade of planktonic diatoms which failed in the survival competition in the unfavorable and deteriorated eco-environment. On the basis of experimental results and natural environment of Xiamen waters and by making reference to the critical criteria of shellfish toxins in various states, a prewarning value 1×105 cells per cubic decimetre of A. tamarense PSP toxicity was proposed for the areas in South China where red tides frequently occur.

  14. 3-D observations of a red tide event in the offshore water along the western Guangdong coast

    Institute of Scientific and Technical Information of China (English)

    XIE Lingling; QI Yiquan; CHEN Qingxiang; HU Jianyu; ZHANG Shuwen; YI Xiaofei; CHEN Fajin; DENG Rui; DENG Xiaodong; WANG Jing

    2015-01-01

    From November 24 to 26, 2014, a red tide event occurred in the offshore water off the Hailing Island located at the western Guangdong coast. The red tide appeared as pink strips distributed within 3 km in the offshore water and extended for about 10 km along the shoreline. During the flood tide, the pink seawater rushed to the beach with breaking waves, forming foam strips on the beach. Guangdong Province Key Laboratory for Coastal Ocean Variation and Disaster Prediction Technologies, Guangdong Ocean University, emergently responded to the event and organized three-dimensional observations from the air, onboard and on beach. The preliminary analyses of the cruise data and water samples indicate that the event was induced by non-toxicNoctiluca scintillans, of which the concentration reaches as high as 4 200 cells/L near the surface and 2 600 cells/L at the bottom.

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

    Science.gov (United States)

    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.

  16. Acute Toxicity of Formalin to the Red-tide Dinoflagellate Prorocentrum minimum Schiller (Protozoa, Mastigophora)

    Institute of Scientific and Technical Information of China (English)

    XU Henglong; SONG Weibo; ZHU Mingzhuang; QIU Yantao; MA Honggang

    2005-01-01

    The acute toxic levels of formalin to a marine red-tide dinoflagellate Prorocentrum minimum Schiller(Mastigophora,Dinoflagellida) were determined by linear regression analysis. The data obtained revealed that there is a close regression relationship between logarithmic concentrations of formalin and mortality probit scales of the organism whenexposure times are1, 2, 6, 12, 24 h. The median lethal concentrations (LC50 values) obtained from correlation analysis for these exposure times (with 95% confidence intervals), were 11.83, 6.76, 4.37, 4.27 and 3.98mgL-1, respectively. A toxicity curve was obtained to connect the exposure time and LC50 value from the correlation between them. The results indicated that P. minimum could be killed or fixed by formalin in the concentration range of 4-12 mgL-1 within 1-24 h.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

  19. Development and Evaluation of Real-time Acoustic Detection System of Harmful Red-tide Using Ultrasonic Sound

    Directory of Open Access Journals (Sweden)

    Donhyug Kang

    2013-03-01

    Full Text Available The toxic, Harmful Algal Blooms (HABs caused by the Cochlodinium polykrikoides have a serious impact on the coastal waters of Korea. In this study, the acoustic detection system was developed for rapid HABs detection, based on the acoustic backscattering properties of the C. polykrikoides. The developed system was mainly composed of a pulser-receiver board, a signal processor board, a control board, a network board, a power board, ultrasonic sensors (3.5 and 5.0 MHz, an environmental sensor, GPS, and a land-based control unit. To evaluate the performance of the system, a trail was done at a laboratory, and two in situ trials were conducted: (1 when there was no red tide, and (2 when there was red tide. In the laboratory evaluation, the system performed well in accordance with the number of C. polykrikoides in the received level. Second, under the condition when there was no red tide in the field, there was a good correlation between the acoustic data and sampling data. Finally, under the condition when there was red tide in the field, the system successfully worked at various densities in accordance with the number of C. polykrikoides, and the results corresponded with the sampling data and monitoring result of NFRDI (National Fisheries Research & Development Institute. From the laboratory and field evaluations, the developed acoustic detection system for early detecting HABs has demonstrated that it could be a significant system to monitor the occurrence of HABs in coastal regions.

  20. Effects of four nitrogen substrates on growth of several red tide species

    Institute of Scientific and Technical Information of China (English)

    颜天; 周名江; 钱培元

    2002-01-01

    --Eight common red tide species including the Dinoflagellates Ale randrium tamarense,Prorocentrum minimum, Prorocentrum mican, Diatoms Skeletonema costatum , Cerataulina pelagica, Leptocylindrus minimus, a Raphidophyte Heterosigma akashiwo and a Chrysophyte Ivohrysis galbana were chosen to study the effect of four nitrogen substrates ( NO3 - N, NH4 - N, Urea - N,Mixed - N) on the growth of these algae. After two transfers, the results showed that at N concentration of 550μrnol, NO3 N was the best nitrogen source among these four nitrogen substrates; Urea - N and Mixed- N were also good for the growth of most algae, but not as good as NO3 - N for some species; NH4 - N inhibited the growth of all these species except H. akashiwo. At concentrations of 280 and 50 μmnol experiments on the growth of I. galbana, P. minimum and L. minimus in NH4 - N and NO3 - N substrates were also performed. The results showed that the growth rates of I. galbana were not significantly different from each other in NO3 - N and NH4 - N substrates both concentrations of 280 and 50 μmol. In concentration of 280μmol NH4 - N substrate, the growth rates of P.minimum and L. minimus were slower than in same concentration of NO3 - N; At concentration of 50μrmol , the growth rate of P. minimum in NH4 - N was not significantly different from that in NO3 - N, while the growth rate of L. minimus was only about 30% of that in NO3 - N substrate.The results indicated that each alga had its own preference in N-substrate and concentration, therefore,different nitrogen substrates may play a role in red tide formation.

  1. Relation Between Chlorophyll-A Concentration and Red Tide in the Intensive Study Area of the Ariake Sea, Japan in Winter Seasons by using MODIS Data

    Directory of Open Access Journals (Sweden)

    Kohei Arai

    2015-10-01

    Full Text Available Relation between chlorophyll-a concentration and red tide in the intensive study area of the back of Ariake Sea, Japan in the recent winter seasons is investigated by using MODIS data. Mechanism of red tide appearance is not so clarified. On the other hand, chlorophyll-a concentration can be estimated with satellite remote sensing data. An attempt is made for estimation of the location and size of red tide appearance. In particular, severe damage due to red tide is suspected in the winter seasons now a day. Therefore, 6 years (winter 2010 to winter 2015 data of MODIS data derived chlorophyll-a concentration and truth data of red tide appearance (the location and the volume which are provided by Saga Prefectural Fishery Promotion Center: SPFPC (once/10 days of shipment data have been investigated. As the results of the investigation, it is found that a strong correlation between the chlorophyll-a concentration and red tide appearance together with the possible sources of the red tide.

  2. Growth inhibition to three red tide microalgae by extracts of Ulva pertusa

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Growth inhibition effect of different concentration of distilled water extract and four polar organic solvent (methanol, acetone, ether and chloroform) extracts of Ulva pertusa on three typical red tide microalgae (Heterosigma akashiwo, Alexandrium tamarense and Prorocentrum micans) were investigated. Liquid-liquid fractionation and HPLC analysis for methanol extract of U. pertusa were carried out.Growth of the three microalgae was significantly inhibited by the distilled water extract of U. pertusa at relatively higher concentration. However, the cells of the three microalgae did not die completely even at high concentration. Methanol extract of U. pertusa showed the highest growth inhibition on the three microalgae, and all the cells of the three microalgae were killed at relatively high concentration. The other three organic solvent extracts of U. pertusa had no apparent effect on the three microalgae. The results of bioassays and HPLC analysis suggested that the inhibitory substances in U. pertusa to the microalgal growth had relatively high polarities. H. akashiwo was the most sensitive one while A. tamarense was the most tolerant one to the growth inhibitory substances.

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

    Institute of Scientific and Technical Information of China (English)

    WANG Renjun; WANG You; TANG Xuexi

    2012-01-01

    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 Heterosigrna akashiwo(Hada)Hada,Skeletonema costatum(Grey.)Grey,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.

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

    OpenAIRE

    Pierce, R. H.; Henry, M S

    2008-01-01

    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 ...

  5. Investigating vertical migration and bloom dynamics of a red tide dinoflagellate: Laboratory observations and a novel sensing approach. (AQU 2)

    OpenAIRE

    Stefanie Moorthi; Beth Stauffer; Carl Oberg; Gaurav Sukhatme; David Caron

    2006-01-01

    Lingulodinium polyedrum is a marine, bioluminescent dinoflagellate that is a common red tide species and potential toxin producer (yessotoxin) along a large expanse of the coast of Southern California. Little is known about the factors leading to bloom formation, or its impact on planktonic food webs. Bloom abundances can reach over 1000 cells/ml, events in which the interplay of physical forces (wind and surface currents) and of algal behavior (vertical migration) presumably play an importan...

  6. AQU 2: Investigating Vertical Migration and Bloom Dynamics of a Red Tide Dinoflagellate: Laboratory Observations and a Novel Sensing Approach

    OpenAIRE

    Stefanie Moorthi; Beth Stauffer; Carl Oberg; Gaurav Sukhatme; David Caron

    2006-01-01

    Lingulodinium polyedrum is a marine, bioluminescent dinoflagellate that is a common red tide species and potential toxin producer (yessotoxin) along a large expanse of the coast of Southern California. Little is known about the factors leading to bloom formation, or its impact on planktonic food webs. Bloom abundances can reach over 1000 cells/ml, events in which the interplay of physical forces (wind and surface currents) and of algal behavior (vertical migration) presumably play an importan...

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

    OpenAIRE

    Olascoaga, M. J.

    2010-01-01

    Analysis of year-long drifter trajectories and records of simulated surface Lagrangian Coherent Structures (LCSs) have suggested the presence of a resilient Cross-Shelf Transport Barrier (CSTB) on the West Florida Shelf (WFS). The CSTB was conjectured to provide a large degree of isolation, which is consequential for the fueling of red tides on the southern WFS by nutrients possibly released by rivers and canals directly on the region. Here this conjecture is thoroughly tested by identifying ...

  8. Influence of Trichodesmium red tides on trace metal cycling at a coastal station in the Great Barrier Reef Lagoon

    OpenAIRE

    Jones, G.; Burdon-jones, C; Thomas, F.

    1982-01-01

    Investigations carried out at a coastal station in the Great Barrier Reef lagoon (GBRL) at Townsville, Australia have shown that the cycling of several trace metals (Fe, Mn, Zn, Cu, Ni, Cd, and Pb) was significantly influenced by the presence of Trichodesmium , a blue-green alga, which throughout the year, frequently forms red tide densities along much of the Queensland coral coast. Whilst decomposition of large masses of Trichodesmium significantly affected metal concentrations, metal specia...

  9. A prolonged red tide of Heterocapsa triquetra (Ehrenberg F. Stein (Dinophyceae and phytoplankton succession in a eutrophic estuary in Turkey

    Directory of Open Access Journals (Sweden)

    S. TAS

    2015-11-01

    Full Text Available A prolonged red tide of Heterocapsa triquetra and phytoplankton succession were investigated in a eutrophic estuary (Golden Horn for a year. Runoff following the rainfall in winter supplied high amounts of nutrients and also created a mesohaline frontal zone in the middle and upper estuary. Red tide of H. triquetra was first observed with an orange-brownish water discoloration at the upper estuary in January. Highest cell density of H. triquetra was 2.7×106 cells l-1 in January and reached to 19.2×106 cells l-1 in April. Successive blooms continued with dinoflagellate Prorocentrum minimum in May and phytoflagellates Eutreptiella marina and Fibrocapsa sp. in summer. High chl-a and dissolved oxygen were measured in the spring depending on algal biomass. Findings indicate that H. triquetra might be adapted to moderate salinity and low temperatures and red tide events should be considered as a response to increasing eutrophication due to high amounts of nutrients. Eutrophication can lead to harmful algal blooms for this area in the near future.

  10. [Semi-analysis algorithm to retrieve pigment concentrations in the red tide area of the East China Sea].

    Science.gov (United States)

    Qiu, Zhong-Feng; Xi, Hong-Yan; He, Yi-Jun; Chen, Jay-Chung; Jian, Wei-Jun

    2006-08-01

    For the purpose of detecting and forecasting research of red tides to reduce the loss, a semi-analytic algorithm to retrieve chlorophyll-a concentrations was established in the area where red tides often brought out, according to the data collected during the red tides cruise in the East China Sea in April 2002. In the algorithm, empirical equations were made based on the coefficients from the in-situ data, including the optical properties of the research area. The in-situ data were used to validate the algorithm. The discrepancy of chlorophyll-a absorption coefficients and concentrations are mainly located in the region of 30%. The root mean deviation of the chlorophyll-a concentrations between the observed and the calculated is 0.24, the maximum relative deviation 40.93%, the mean relative deviation 18.83% and the correlation coefficient 0.83. The results show that the precision of the algorithm is high and the algorithm is fit for the research area. PMID:17111604

  11. Biological activity of a red-tide alga--A. tamarense under co-cultured condition with bacteria

    Institute of Scientific and Technical Information of China (English)

    SU Jian-qiang; YU Zhi-ming; TIAN Yun; SONG Xiu-xian; HONG Hua-sheng; ZHENG Tian-ling

    2005-01-01

    The relationship between Alexandrium tamarense(Lebour) Balech, one of red-tide alga, and two strains of marine bacteria,Bacillius megaterium(S7 ) and B. halmapulus(S10) isolated from Xiamen Western Sea, was investigated by evaluating the growth state of A. tamarense and the variation of β-glucosidase activity in co-culture system. The results showed the growth and multiplication of the alga were related with the concentration, genus speciality of the bacteria, and growth stage of the alga itself. The growth of A. tamarense was obviously inhibited by S7 and S10 at high concentration. Either inhibition or promotion contributed much more clearly in earlier than in later stage of the growth of the alga. Furthermore, there was a roughly similar variation trend of the activity of extra-cellular enzyme, β-glucosidase, in the water of the separately co-cultured bacteria S7 and S10 with the alga. The β-glucosidase activity(β-GlcA) rapidly increased during the later algal growth accompanying the increase of the lysis of the alga cells. The obvious inhibition of A. tamarense by marine bacteria at high concentration and evident increase of β-GlcA in co-colture system would help us in better understanding the relationship between red-tide alga and bacteria, and also enlightened us the possible use of bacteria in the bio-control of red-tide.

  12. Phosphorus cycling in the red tide incubator region of Monterey Bay in response to upwelling

    Directory of Open Access Journals (Sweden)

    KatherineRose MarieMackey

    2012-02-01

    Full Text Available 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 phytoplankton and bacteria 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 3 cruises. Upwelling led to a 10-fold increase in dissolved inorganic (DIP in surface waters, reaching ~0.5 mol L-1. This DIP was drawn down rapidly as upwelling relaxed over a period of 1 week. Relatively low ratios of nitrate to DIP uptake (~5:1 suggest that luxury P uptake was occurring as phytoplankton bloomed. Dissolved organic (DOP remained relatively constant (~0.3mol 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 then DOP, suggesting that P is a regulating, rather than 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 the surfaces of intact phytoplankton cells, possibly indicative of close, beneficial phytoplankton-bacteria interactions.

  13. Influence of the concentration ratio of nitrogen to phosphorus on the growth and interspecies competition of two red tide algae

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The growth and interspecies competition of two red tide algal species Thalassiosira pseudonana Hasle et Heimdal and Gymnodinium sp. were studied under different concentration ratios of nitrogen to phosphorus, and the algal batch culture experiments were conducted. The physiological and biochemical indexes were measured periodically, including the maximum comparing growth rate, relative growth rate, average double time and chlorophyll a concentration. The results showed that when the concentration ratio of nitrogen to phosphorus was 16∶ 1, the maximum comparing growth rate,relative growth rate and chlorophyll a concentration of Thalassiosira pseudonana all reached the highest,and average double time was the shortest. This implied that the optimal concentration ratio of nitrogen to phosphorus of Thalassiosira pseudonana is 16∶ 1. When the concentration ratio of nitrogen to phosphorus was 6∶ 1, the maximum comparing growth rate, relative growth rate and the chlorophyll a concentration of Gymnodinium sp. reached the highest,and average double time was the shortest, so the optimal concentration ratio of nitrogen to phosphorus of Gymnodinium sp. is 6∶ 1. From the growth curves as indicated both in the cell density and the chlorophyll a concentration, it is suggested that the influence of concentration ratio of nitrogen to phosphorus on the chlorophyll a concentration and the cell density are almost the same. Different concentration ratios of nitrogen to phosphorus had weak influence on community succession and the competition between the two algae. Gymnodinium sp. may use the phosphorus in vivo for growth, so it is important to pay attention to the concealment of phosphorus, in order to avoid the outbreak of red tide. On the basis of the importance of nitrogen and phosphorus and the ratio of their concentration, the possible outbreak mechanism of red tide of the two algae was also discussed.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Johnson Jillian G

    2011-07-01

    Full Text Available Abstract 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

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

    OpenAIRE

    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 concentratio...

  18. Red tide evolution in the Mazatlán Bay area from remotely sensed sea surface temperatures

    OpenAIRE

    Raúl Aguirre Gómez; Román Alvarez; Olivia Salmerón García

    1999-01-01

    The evolution of a red tide episode in Mazatlán Bay, Mexico, during February 1996 is described from images of sea surface temperatures (SST), obtained from the advanced very high resolution radiometer (AVHRR). An initial nearshore high surface temperature of 24°C was followed by a sharp decrease of 2.5°C due to wind cooling. Finally, a warmer condition was re-established at the nearshore region. The sequence of satellite images showed potential for identifying short-term oceanic processes res...

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

    Science.gov (United States)

    Olascoaga, M J

    2010-01-01

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

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

    Directory of Open Access Journals (Sweden)

    M. J. Olascoaga

    2010-12-01

    Full Text Available 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.

  1. 有害赤潮的形成机制与防治对策%Formation Mechanism and Countermeasures of Harmful Red Tide

    Institute of Scientific and Technical Information of China (English)

    周靖淇

    2015-01-01

    The main reason of the formation of harmful red tide is miniature planktonic algae; in addition some single-celled plankton can form the red tide. The color of red tide is not only red, there may have different colors like red, green, gray, brown and so on according to the causes. In recent years, the incidence of harmful red tide increased year by year, which has caused gradually increasing harm in the world.%有害赤潮形成的主要原因就是微型浮游藻类,除了浮游海藻之外,还有一些单细胞的浮游生物也是可以形成赤潮的。赤潮并不是只有红色,根据形成原因可能会有红色、绿色、灰色、褐色等不同的颜色。近年来,有害赤潮发生率逐年升高,在全球造成的危害也逐渐增多。

  2. Spatial-temporal Distribution and Hazard Grading of Red Tide and Variation of Red-tide Species in Qingdao Adjacent Sea Area%青岛近海赤潮灾害分级与时空分布及赤潮生物的变化

    Institute of Scientific and Technical Information of China (English)

    刘霜; 张继民; 张洪亮; 李钦亮; 崔文林

    2014-01-01

    根据赤潮发生面积和赤潮藻类的危害类型,将青岛近海发生的赤潮划分为特大、重度、中度、轻度和轻微共计5个灾害级别。结果表明,1990-2013年青岛近海共计发生赤潮33次,以轻微灾害和轻度灾害为主,其它级别尚未发生;其中,发生面积小于10 km2赤潮占总数的51.5%,60.6%的赤潮由基本无害的赤潮种类引起,发生范围以胶州湾和浮山湾近海为主;赤潮次数和面积基本呈现4~5年的波动周期,高发期集中在每年的6-8月;主要赤潮生物种类是红色中缢虫(Mesodinium rubrum)和夜光虫(Noctiluca scintillans);引发赤潮的生物种类逐渐增多,甲藻比例升高,罕见种类逐渐出现。赤潮种类的变化反映出青岛近海浮游植物的种类组成发生了改变,与期间青岛近岸海洋环境的变化密切相关。%Red tides occurred in Qingdao adjacent sea area were classified into five levels,i,e.,extra large, large,moderate,mild and slight,according to the red tide scales and hazard types.Thirty-three red tide events were recorded from 1990 to 2013 with the main types of slight red tide and mild red tide.Among them,the scale of red tides was less than 10 km2 accounting for 5 1 .5%of the total red tides and 60.6%of the red tides were caused by harmless red tide species.Jiaozhou Bay and Fushan Bay adjacent sea area were the red tide-frequent-occurrence areas.The frequencies and scales of red tides peaked every four to five years from June to August,with the main red tide species of Mesodinium rubrum and Noctiluca scintillans.The species of red tide gradually increased with a rising tendency of Pyrrophyta occurrence frequency,even rare species have appeared in the past few years.The changes of the red tide species indicated that the species composition of phytoplankton in Qingdao inshore area has changed,which is closely related to the marine environment of Qingdao near-shore areas.

  3. Study of Interaction between Red-tide Toxin, Domoic Acid and Double -stranded DNA by Capillary Zone Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    Da Zhi LI; Xin Ya HE; Hui WANG; Li SUN; Bing Cheng LIN

    2004-01-01

    The interactions between amnesic red-tide toxin, domoic acid (DA) and 14mer double-stranded DNA (dsDNA with three kinds of sequences) were studied by capillary zone electrophoresis (CZE). For the dsDNA with a sequence of 5'-CCCCCTATACCCGC-3', the amount of free dsDNA decreases with the increase of added DA; and the signal of DA-dsDNA complex was observed. Meanwhile, the other two dsDNAs, 5'-(C)12GC-3' and 5'-(AT)7-3', the existence of DA could not lead to the change of dsDNA signal and indicated that there is no interaction between DA and these two dsDNAs.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    AbstractA 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...

  6. Approach to red tide prediction on RBF neural network%基于RBF神经网络的赤潮预测方法

    Institute of Scientific and Technical Information of China (English)

    李慧; 顾沈明

    2012-01-01

    Red tide is an anomalous phenomenon and is characterized by abruptness and nonlinearity, so the red tide prediction has been a hotspot in the oceanographic studies. The fundamentals of RBF neural network are briefly introduced, and the application of artificial neural network method to the red tide prediction is discussed. Based on the RBF neural network, the simulation experiments are also illustrated by using red tide monitoring data, and the experimental analysis is also proposed.%赤潮是一种由多因素综合作用引发的生态异常现象,具有突发性及非线性等特点.对其进行预测预报一直是海洋科学研究的热点.简要介绍了RBF神经网络的基本原理,探讨了应用该人工神经网络进行赤潮预测的方法.利用RBF神经网络模型对赤潮灾害监测数据进行仿真实验,并对结果进行了分析.

  7. 赤潮灾害经济损失评估技术方法%Technology and Method for Economic Losses Assessment of Red Tide Disasters

    Institute of Scientific and Technical Information of China (English)

    文世勇; 宋旭; 田原原; 张强; 陈晨; 高树刚; 赵冬至

    2015-01-01

    In order to effectively cope with the red tide disasters prevention and reduction,relief and post dis-aster management needs,firstly,according to related research results and the damage characteristic of red tide dis-asters,economic loss assessment index of red tide disasters is put forward based on the actual needs and the opera-tional data that can be got in the operational work.Secondly according to disasters economic theory and economic losses assessment advanced ideas of other natural disasters,operational application method for economic losses as-sessment of red tide disasters is established,including marine aquaculture economic losses,coastal tourism eco-nomic losses,operational and emergency monitoring costs of red tide disasters,and red tide disasters disposal cost assessment model.Finally,the technical process of operational application technology and method for economic los-ses assessment of red tide disasters is put forward.%为有效应对赤潮灾害防灾减灾、灾后救援及管理的需求,在综合分析前人提出的赤潮灾害损失评估技术方法的基础上,参考赤潮灾害对受灾体的危害特点,结合实际工作的需求及在实际中可获取的业务数据,提出了赤潮灾害经济损失评估指标体系;根据灾害经济学理论,借鉴其他自然灾害经济损失评估的先进思想,采用市场价格法,分别建立了包括海水养殖业经济损失、滨海旅游业经济损失、赤潮灾害业务与应急监测费用和赤潮灾害处置费用的赤潮灾害经济损失评估模型;最后,提出了赤潮灾害损失评估的技术流程。

  8. 中国近海赤潮基本特征与减灾对策%Basic characteristics and mitigation countermeasures of red tides in China seas

    Institute of Scientific and Technical Information of China (English)

    洛昊; 马明辉; 梁斌; 朱容娟; 梁雅惠

    2013-01-01

    Both the history and the current status of the red tide in China Seas were described, and the temporal-spatial distribution and characteristics were discussed, as well as the relative control measure were set forth. According to the statistics, (1) From 1933 to 2011, 1047 times of red tides were recorded in China Seas. The frequency and scale of red tide have increased significantly since 2000. (2) Red tide distributed in both south and north coasts in China. Distribution patterns were different obviously. Estuaries and inner bays were high-frequency red tide areas, in which East China Sea was the highest frequency. High-frequency season was from May to August, and red tide occurred in the South China Sea all year round. (3) Up to 2009, the frequency of red tides caused by dominant species counted as 417, about 45 percent of the total events; and frequency of toxic red tides increased significantly in recent years. (4) Major nutrient loads were considered to be one of the main reasons that induced the red tide events. Early warning and strengthening pollution control of nitrogen and phosphorus loads would be the main measures to prevent HABs.%通过描述我国沿海赤潮发生历史和现状,深入探讨了我国赤潮的时空分布特征及变化规律,并提出了应对赤潮灾害的减灾对策。分析结果显示:(1)1933年至2011年间,我国海域共观测到赤潮事件1047起。2000年以后我国进入赤潮高发期,赤潮发现频率和影响范围明显增加。(2)我国沿海从南到北均有赤潮分布,时空分布差异显著。其中,河口、内湾为赤潮多发区。东海年发现频率最高,高发期集中于每年4-9月水温较高的季节,南海一年四季均有发现。(3)截至2009年,我国由优势种引发赤潮的次数为417次,约占赤潮总数的45%,有毒赤潮发现频率明显增加。(4)对营养盐输入为赤潮发生提供了物质基础进行了探讨,提出了加强赤潮

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

    Science.gov (United States)

    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

  10. The killer tides

    Digital Repository Service at National Institute of Oceanography (India)

    Devassy, V.P.; Bhat, S.R.

    . Various measures adopted to control or contain such harmful events have either proved ineffective or are economically unviable. Red tides generally break out under favourable environmental conditions such as calm, sunny weather and gently breeze or when...

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

    Science.gov (United States)

    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

  12. 赤潮灾害损失评估体系构建%Construction of evaluation system of red tide disaster loss

    Institute of Scientific and Technical Information of China (English)

    温艳萍; 任光超

    2011-01-01

    赤潮灾害已经成为影响海洋经济健康、稳定、持续发展的重要制约因素,建立起一套全面、系统的赤潮灾害损失评估体系非常必要.现阶段在赤潮灾害损失评估中主要存在评估指标归类随意、评估体系构建局限和评估指标选取不全面三大缺陷.基于层次分析法构建赤潮灾害损失评估体系对赤潮灾害损失进行定量分析,为我国赤潮灾害损失评估提供依据.%Red tide disaster has become a significant constraint against ocean economy developing healthily,steadily,and persistently.Thus,it is extremely important to set up a system that estimates red tide disaster loss roundly and systematically.At the present stage,defects in the evaluation of red tide loss can be concluded into three aspects: random classifying of evaluation indexes,circumscribed construction of evaluation system,and incomplete selection of evaluation indexes.It is required that,aimed at the characteristic of current loss of red tide disaster and base on abundance investigation,thorough evaluation model of disaster loss should be reconstructed.

  13. Red tides caused by Exuviaella cordata and Exuviaella marina%卵甲藻Exuviaella cordata 和Exuviaella marina赤潮的初步研究

    Institute of Scientific and Technical Information of China (English)

    周遵春; 闫喜武; 庞军辉; 马志强; 薛克; 雷善敏

    2001-01-01

    Red tides caused by Exuviaella cordata and biology of Exuviaella marina (the first occurrence in shrimp ponds of Qingdui Fisheries Coorporation of Zhuanghe) were described. The reason why red tide occurred and its harmful effects were evaluated. The conformation characteristic, ecological habits of Exuviaella cordata and Exuviaella marina was briefly described. Three species of raft-cultured shellfishes collected at red tides in Dalian Wan Bay were tested for the shellfish poison.%报道了由心形卵甲藻(Exuviaella cordata)和海洋卵甲藻(Exuviaella marina)引发的赤潮(前者于1991年发生在庄河青堆水产公司虾池中,后者于1999年7月发生在大连湾)。并对赤潮发生的原因、危害进行了分析,对引发赤潮藻类的形态和生活习性进行了描述,对大连湾赤潮区养殖的3种贝类进行了贝毒检测。

  14. 多波段卫星遥感海洋赤潮水华的方法研究%Algorithms of multiband remote sensing for coastal red tide waters

    Institute of Scientific and Technical Information of China (English)

    毛显谋; 黄韦艮

    2003-01-01

    The spectral characteristics of the coastal waters in East China Sea was studied using in situ measurements, andt he multiband algorithms of remote sensing for bloom waters was discussed and developed. Examples of red tide detection using the algorithms in the East China Sea were presented. The results showed that the algorithms could provide information about the location and the area coverage of the red tide events.

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

    Science.gov (United States)

    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

  16. Observation and analysis of the diluted water and red tide in the sea off the Changjiang River mouth in middle and late June 2003

    Institute of Scientific and Technical Information of China (English)

    ZHU Jianrong; WANG Jinhui; SHEN Huanting; WU Hui

    2005-01-01

    An interdisciplinary comprehensive survey was conducted in middle and late June 2003 with the Multi- Parameter Environmental Monitoring System YSI6600 and water sample analysis in the sea off the Changjiang River mouth. The Changjiang diluted water (CDW) extended offshore with a bimodal structure during the observation, one extending toward the southeast, the other toward the northeast. The main axis of the CDW extended toward the northeast. A severe red tide with wide spatial extent and brown water color happened. Chlorophyll-a (Chl-a) distribution near the Changjiang River mouth also presented a bimodal structure, and its position and shape were roughly consistent with the extension of the CDW. Water sample analysis indicated that the serious eutrophication produced by the huge amount of nutrient load via the Changjiang River was the main cause of red tide bloom. The dominant algal specie at the most measurement stations was skeletonema costatum. There existed three centers of higher Chl-a concentration, locating at (122.45°E, 31.5°N), (122.4°E, 30.8°N) and (123.25°E, 30.0°N), respectively. The red tide at (122.45°E, 31.5°N) was located in the major modal of CDW and higher turbid seawater, its dominant algal specie was prorocentrum dentatum with density 2.23×106 ind/L. The red tide at (122.4°E, 30.8°N) was located in the second modal of CDW and lower turbid seawater, its dominant algal specie was skeletonema costatum with density 1.0×107 ind/L. The dominant algal specie at (123.25°E, 30.0°N) was Heterocapsa circularisquama horiguchi with density 2.0×106 ind/L, which was found for the first time forming red tide in the sea off the Changjiang River mouth.

  17. Determining Atmospheric Aerosol Content With An Infra-red Radiometer

    CERN Document Server

    Daniel, M K; Chadwick, P M

    2014-01-01

    The atmospheric attenuation of Cherenkov photons is dominated by two processes: Rayleigh scattering from the molecular component and Mie scattering from the aerosol component. Aerosols are expected to contribute up to 30 Wm$^{-2}$ to the emission profile of the atmosphere, equivalent to a difference of ~20C to the clear sky brightness temperature under normal conditions. Here we investigate the aerosol contribution of the measured sky brightness temperature at the H.E.S.S. site; compare it to effective changes in the telescope trigger rates; and discuss how it can be used to provide an assessment of sky clarity that is unambiguously free of telescope systematics.

  18. Determining atmospheric aerosol content with an infra-red radiometer

    CERN Document Server

    Daniel, Michael; 10.1063/1.4772360

    2012-01-01

    The attenuation of atmospheric Cherenkov photons is dominated by two processes: Rayleigh scattering from the molecular component and Mie scattering from the aerosol component. Aerosols are expected to contribute up to 30 Wm$^{-2}$ to the emission profile of the atmosphere, equivalent to a difference of $\\sim20^\\circ$C to the clear sky brightness temperature under normal conditions. Here we investigate the aerosol contribution of the measured sky brightness temperature at the H.E.S.S. site; compare it to effective changes in the telescope trigger rates; and discuss how it can be used to provide an assessment of sky clarity that is unambiguously free of telescope systematics.

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

    Science.gov (United States)

    Fukuda, Yasuhiro; Endoh, Hiroshi

    2006-09-01

    Noctilucid protozoans are among the dinoflagellates that cause red tides. Sexual reproduction may occur in this group, as they sometimes undergo gametogenesis. However, the life cycle, in particular the developmental process after gamete fusion, has not been fully elucidated. We have been able to maintain clonal cultures of Noctiluca scintillans throughout the whole life cycle and have revealed new details of various stages. In trophont populations, a small fraction of cells spontaneously transform into gametogenic cells, which undergo two successive nuclear divisions, without cellular division, probably corresponding to meiosis. The products of nuclear division migrate to the cell surface with a small amount of cytoplasm, and there further synchronously divide 6-8 times, during which the division products are connected by thin cytoplasmic bridges. Thus, numerous gametes with a semi-spindle body shape are released from the mother cell ghost. They retain two flagella that differ in length and motion, as is typical of dinoflagellates. The presence of longitudinal and transverse grooves indicates that dinoflagellate-like characteristics are conserved in the gametes, although they are not present in the specialized trophonts. Zygotes with four flagella result from the fusion of two isogametes. The zygotes change shape from spindle to spherical, with a reduction in flagellar number. The developing cell acquires a tentacle and crust, similar to large trophonts, and begins to develop a cytoplasmic network, thus completing the transformation into a miniscule trophont. These early trophonts grow to maturity as cell size increases. Our observations of the life cycle of N. scintillans may provide clues for understanding the evolutionary origin of noctilucae. PMID:17070765

  20. 广东沿海赤潮发生与城市发展的关系%A relationship between red tide outbreaks and urban development along the coasts of Guangdong Province

    Institute of Scientific and Technical Information of China (English)

    刘晓南; 王为

    2004-01-01

    Red tides are one of the main coastal catastrophic events in Guangdong Province of southern China. The comparison between the number of red tide events and the development indexes of cities along the coasts of the province shows that the regional differences in red tide outbreaks has close relations with the coastal urban developments. The cause for an initiation of red tide blooms may be natural factors, while wastewater caused by the fast development of population, industry and aquiculture of the coastal cities enhanced the blooms. It may explain why the two periods of frequent outbreaks of the red fides over the last two decades matched the urban developments in the coastal areas of Guangdong not only spatially but also temporally. The red tides in the ftrst period were restricted only to the coasts of middle Guangdong, where urbanization process was at a higher speed than the other coastal areas of the province. In the second period, fast development of the coastal cities in eastern Guangdong led to an increase in the occurrence of red fides in local sea areas of the same coasts.

  1. A triphase red tide in Tong'an Bay of Xiamen Seas and its causes analysis%厦门同安湾海域一次三相型赤潮及其成因分析

    Institute of Scientific and Technical Information of China (English)

    俞秀霞

    2012-01-01

    通过监视监测2011年7月26日-8月7日发生在厦门同安湾的赤潮,对赤潮发生时的水文气象、化学、生物因子等进行分析。结果表明,本次赤潮为三相混合型赤潮,赤潮生物为中肋骨条藻(Skeletonema costatum)、血红哈卡藻(Akashiwo sanguinea)和角毛藻(Chaetoceros sp.),赤潮最大面积为105km2。水体的富营养化、持续的高温天气和小潮期水体的相对稳定是本次赤潮发生的基本条件,"洛坦"台风的气压影响以及降雨导致的盐度急剧下降是此次赤潮的诱因。%A red tide in Tong'an Bay of Xiamen Seas during July 26th to August 7th in 2011 was reported in this paper. Hydrological meteorological, chemistry and biological factors were analyzed in the occurrence of red tide. The results showed that this red tide with the area of 105 km2 was a hybrid triphase red tide, and the red tide species included Skeletonema costatum, Akashiwo sanguinea, Chaetoceros sp. The basic conditions of this tide were eutrophication, continuous high air temperature and the stable water body of neap tide, the air pressure due to "Luotan" typhoon and sharp decline of salinity due to rainfall also contributed to this red tide.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    International Nuclear Information System (INIS)

    Highlights: • Sublethal brevetoxin exposure affects manatee immune function. • Plasma brevetoxin levels correlate with oxidative stress in rescued manatees. • Brevetoxin exposure affects lymphocyte proliferation in rescued manatees. • Plasma brevetoxin concentrations ranged from 0 to 19 ng PbTx-3 eq/mL. - Abstract: 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

  5. Application of improved CSFCM clustering in red tide monitoring%改进的CSFCM聚类算法及其在赤潮监测中的应用

    Institute of Scientific and Technical Information of China (English)

    王兴强; 刘长兴; 刘国伟; 张旭东

    2012-01-01

    为满足海洋监测系统中赤潮监测数据的信息挖掘需求,在深入探讨数据挖掘相关算法的基础上,提出一种新的基于分组属性加权聚类的CSFCM算法.该算法将COSA(Clustering Objects on Subsets of Attributes)算法与模糊C均值算法相结合并引入相似关系预处理,再对准则函数和聚类模型加以改进.实验结果表明,该算法适用于赤潮监测数据挖掘的实时聚类需求,准确率高,为赤潮预报提供必要的决策依据.%In order to satisfy data mining requirements of red tide monitoring data in marine observation system, a novel CSFCM clustering with subsets of attribute' s weights, based on thorough discussion of algorithms for data mining, is introduced. In the proposed method, a classic COSA(Clustering Object on Subsets of Attributes) algorithm and the fuzzy C-means algorithm are adopted with pre-treatment of similary relation and then the criterion function and clustering model are improved. The experimental results demonstrate the applicability, feasibility and efficiency of this new algorithm on data mining of red tide monitoring, and it provides necessary decision-making basis for red tide forecast.

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

    Science.gov (United States)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, Catherine J., E-mail: cjwalsh@mote.org [Marine Immunology Program, Mote Marine Laboratory, 1600 Ken Thompson Parkway, Sarasota, FL 34236 (United States); Butawan, Matthew, E-mail: mattbutawan@outlook.com [Marine Immunology Program, Mote Marine Laboratory, 1600 Ken Thompson Parkway, Sarasota, FL 34236 (United States); Yordy, Jennifer, E-mail: jennifer.e.balmer@gmail.com [Marine Immunology Program, Mote Marine Laboratory, 1600 Ken Thompson Parkway, Sarasota, FL 34236 (United States); Ball, Ray, E-mail: Ray.Ball@lowryparkzoo.com [Lowry Park Zoo, 1101 W Sligh Ave, Tampa, FL 33604 (United States); Flewelling, Leanne, E-mail: Leanne.Flewelling@MyFWC.com [Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission, 100 8th Ave SE, St. Petersburg, FL 33701 (United States); Wit, Martine de, E-mail: Martine.deWit@MyFWC.com [Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission, 100 8th Ave SE, St. Petersburg, FL 33701 (United States); Bonde, Robert K., E-mail: rbonde@usgs.gov [U.S. Geological Survey, Sirenia Project, 7920 NE 71st Street, Gainesville, FL 32653 (United States)

    2015-04-15

    Highlights: • Sublethal brevetoxin exposure affects manatee immune function. • Plasma brevetoxin levels correlate with oxidative stress in rescued manatees. • Brevetoxin exposure affects lymphocyte proliferation in rescued manatees. • Plasma brevetoxin concentrations ranged from 0 to 19 ng PbTx-3 eq/mL. - Abstract: 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

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

    Science.gov (United States)

    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

  9. INVESTIGATION THE BEHAVIOR OF MODIS OCEAN COLOR PRODUCTS UNDER THE 2008 RED TIDE IN THE EASTERN PERSIAN GULF

    Directory of Open Access Journals (Sweden)

    M. Ghanea

    2015-12-01

    Full Text Available 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

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

    Science.gov (United States)

    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

  11. 基于物联网的赤潮监测系统%Red Tide Monitoring System Based on the Internet of Things

    Institute of Scientific and Technical Information of China (English)

    郭阳雪; 孔祥洪; 杨渭; 薛俊增

    2013-01-01

    It is of great significance to have a rapid real-time monitoring of the change of water quality before red tides outbreak. In this paper, the monitoring system of red tide was designed by using the technology of the Internet of Things. In the system, the red tide was monitored by wireless sensors, and its geographic information position was oriented by GPS. Digital and analog sensors were connected to the mobile sensor module so that the system could monitor multiple water parameters, and could accurately provide the variation gradient of the salinity, temperature, flow rate, and chlorophyll. The data was issued by using C/S structure. The data and the user interface could be displayed, and the user' s interface was realized by ArcGIS Map. Practice proves that the outbreak of red ride can be accurately forecasted by using the monitoring system.%近海赤潮的频繁爆发对海洋环境和海洋经济产生了极大的破坏力,对赤潮的监测与预报尤为重要.为了能够实时快速地监测赤潮发生前的水质的变化情况,利用物联网技术,设计了近海赤潮环境的监测系统.在该系统中综合运用无线传感网络技术、嵌入式计算技术、移动通信技术、GPS技术,对赤潮发生的重灾区进行动态监控,移动传感模块可以与数字与和模拟类传感器相连接,可监测多个水体参数,能够准确的提供海水的盐度、温度、流速、叶绿素等参数的变化梯度.该系统采用C/S构架实施数据的发布和数据用户界面的显示及交互,利用ArcGIS Map实现用户的交互界面,达到对赤潮爆发灾情的预报.

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

    KAUST Repository

    Brindley, Helen

    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

  13. NUMERICAL SIMULATION OF SUMMER CIRCULATION IN THE EAST CHINA SEA AND ITS APPLICATION IN ESTIMATING THE SOURCES OF RED TIDES IN THE YANGTZE RIVER ESTUARY AND ADJACENT SEA AREAS

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiu-hua; ZHU Liang-sheng; ZHANG Hong-sheng

    2007-01-01

    Based on the COHERENS (a Coupled Hydrodynamical Ecological model for Regional Shelf seas), a three-dimensional baroclinic model for the summer of East China Sea (ECS) was established with the sigma-coordinate in the vertical direction and spherical coordinate in the horizontal direction. The circulation patterns of the Kuroshio Current, the Taiwan Warm Current (TWC), the Tsushima Current and the Yangtze Diluted Water (YDW) were successfully simulated with this model. The calculated results are fairly consistent with previous observations and studies. Based on this baroclinic current field, the Lagranian particles tracking was simulated to estimate the possible origins of the red tides frequently occurring in the Yangtze River estuary and its adjacent sea areas. If there are "seeds" (cysts) of the red tide algae at the seabed of the Taiwan Strait, the offshore of Fujian and Zhejiang Provinces and the northeast Taiwan Island, those are extremely possible sources of the red tides in the Yangtze River estuary and its adjacent sea areas. Field data are needed to confirm it. Numerical simulation to estimate the source of the red tides is a new application of the Lagrangian transport in the marine ecology.

  14. 基于光谱差异的东海赤潮提取算法%A new algorithm of red tide monitoring based on the spectral differences in the East China Sea

    Institute of Scientific and Technical Information of China (English)

    徐晓晖; 毛志华; 陶邦一

    2013-01-01

    Red tide is one of the most serious marine hazards.It not only destroys marine fishery production,deteriorates the marine environment,affects coastal tourist industry,but also causes human health problems.The East China Sea is the region of the "high incidence" of the red tide disaster in China:both in the frequency and the area are significantly higher than others.Remote sensing technology has been proved to be one of the most effective means of red tide monitoring.From the spectral curves,we can see that the spectral of the red tide water and non-red tide water has significant difference:there are two peaks and two valleys in red tide water,while there are no these two peaks and two valleys in non-red tide water.Based on the spectral differences,a new algorithm was developed with conditions of Rrs 555/Rrs 488> 1.5,and Rrs 678— Rrs 667 >0 to extract the red tide information.The algorithm can determine effectively the locations from satellite data of red tide,and it is good corresponding to the results in the official bulletin.Therefore,this algorithm is suitable to monitor the red tide from satellite data in the East China Sea.%赤潮是最严重的海洋灾害之一,它不仅破坏海洋渔业生产、恶化海洋环境、影响滨海旅游业,而且还会影响人类健康.东海是我国赤潮灾害的“高发区”,赤潮发生次数和面积均明显高于其它海区.遥感是赤潮监测的最有效的手段之一,从光谱曲线可以看出,赤潮水体和非赤潮水体光谱曲线有明显的区别,前者呈现出2个吸收峰和2个反射峰,而后者不具备该特征.基于光谱差异,本文提出了1种新的赤潮提取算法:Rrs555/Rrs488>1.5且Rrs678—Rrs667>0.该算法能有效地确定卫星数据中赤潮的位置,与公报的赤潮位置吻合得较好.因此,该算法适用于卫星数据的东海赤潮信息提取.

  15. Study on the relationship between red tides and tropical cyclones at the Xiamen Bay%近十年厦门湾赤潮发生与热带气旋的关系研究

    Institute of Scientific and Technical Information of China (English)

    曾银东; 陈剑桥; 李雪丁

    2011-01-01

    利用2001-2010年历史赤潮记录、热带气旋、500hPa高空形势、地面形势以及逐日的气温、气压、相对湿度和风速等资料,分析研究了近十年厦门湾赤潮发生与热带气旋的关系.结果表明,在热带气旋外围暖舌的影响下,厦门湾往往会发生赤潮.热带气旋诱发厦门湾赤潮的时间主要集中在6-8月,诱发赤潮的热带气旋可归纳为南海西行型、台湾岛东部靠近型和南海东移北上型3类.其中热带气旋南海西行型诱发厦门湾赤潮较多.%Based on the data collected of the red tide, tropical cyclones, 500hPa Height, surface pressure, temperature, pressure, relative humidity and wind speed from year 2001 to year 2010, the influence of tropical cyclone on red tide is analyzed at the Xiamen Bay. It showed that the red tide always occurred when the outer circulation warm tongue of tropical cyclone influenced the Xiamen Bay. It was found that the red tide always occurred in June, July and Agust. Three typical synoptic patterns of tropical cyclone may triggered the red tide: the Tropical-Cyclone -Moving-Westward type, the Tropical-Cyclone-Close-To-East-Taiwan-Island type and the Tropi-cal-Cyclone-Moving-Northward-In-South-China-Sea type,whereas the Tropical-Cyclone-Moving-Westward type is the most important synoptic situation.

  16. Analysis of Inherent Optical Properties in the Occurrence and Declination of a Red Tide%赤潮生消过程中的水体固有光学性质分析

    Institute of Scientific and Technical Information of China (English)

    郝艳玲; 曹文熙; 马毅; 崔廷伟; 张杰

    2011-01-01

    在珠江口海域海洋光学浮标实验中获取一次聚生角毛藻赤潮生消过程的水体光学数据和相应的生化数据.利用该数据,分析了赤潮生消过程中水体光谱吸收和后向散射等光学性质的时间序列变化.研究发现,在赤潮生消过程中,浮游植物色素、非藻类颗粒物以及黄色物质等水体组分吸收变化显著,赤潮爆发期各组分光谱吸收增强并达到最大值,赤潮消亡期各组分光谱吸收降低并至最小值;赤潮爆发期与赤潮发展和消亡期相比,浮游植物的光谱吸收贡献增加约16%,黄色物质的吸收贡献减小约18%,而非藻类颗粒物的吸收贡献变化不大;赤潮爆发期后向散射系数明显增大,日变化幅度大,赤潮发展期和赤潮消亡期后向散射系数较小,赤潮消亡期后向散射系数降至最低;颗粒物后向散射系数与叶绿素a浓度的相关性优于悬浮物浓度.有机颗粒物浓度虽然在总颗粒物浓度中占主导地位,但是颗粒物后向散射与无机颗粒物的相关性更高.%During optical buoy experiments in the Pearl River (Zhujiang) mouth regions, time series of bio-optical data of Chaetoceros socialis red tide is obtained. By using the data, variation of ocean optical properties (absorption and backscattering properties) in the occurrence and declination of red tide is analyzed. Results show that the absorption of various components such as phytoplankton pigments, detritus and colored dissolved organic matter changes dramatically, the absorption of various components increases and reaches maximum values in red tide outbreak period, then the absorption of various components decreases and reaches minimum values in red tide declination period. Compared with red tide development and declination period, contribution of phytoplankton pigment increases by 16%, and that of colored dissolved organic matter decreases by 18% , but that of detritus has little changes for red tide out break

  17. 基于多源遥感数据的连云港海域赤潮信息提取研究%Red Tide Information Extraction Based on Multi-source Remote Sensing Data in Haizhou Bay

    Institute of Scientific and Technical Information of China (English)

    卢霞; 焦明连

    2011-01-01

    [Objective] The aim was to extract red tide information in Haizhou Bay by using multi-source remote sensing data. [ Method] Red tide in Haizhou Bay was studied based on multi-source remote sensing data, such as IRS-P6 data on October 8, 2005, Landsat-5 TM data on May 20, 2006, MODIS 1B data on October 6, 2006 and HY-1B second-grade data on April 22, 2009, which were preprocessed through geometric correction, atmospheric correction, image resizing and so on firstly. At the same time, synchronous environment monitoring data of red tide water were acquired. Then, band ratio method, chlorophyll-a concentration method and secondary filtering method were adopted to extract red tide information. [Result] On October 8, 2005, the area of red tide was about 20. 0 km2 in Haizhou bay. There was no red tide in Haizhou bay on May 20, 2006. On October 6, 2006, large areas of red tide occurred in Haizhou bay, with area of 436.5 km2. On April 22, 2009, red tide scattered in Haizhou bay, and its area was about 10. 8 km2. [ Conclusion] The research would provide technical ideas for the effective implementation of red tide forecast and warning by the environmental monitoring department of Lianyungang.%[目的]利用多元遥感数据提取连云港海域赤潮信息.[方法]以小尺度连云港海州湾赤潮为研究对象,选用2005年10月8日IRS-P6数据、2006年5月20日Landsat 5-TM数据、2006年10月6日MODIS lB数据以及2009年4月22日HY-1B的2级数据为遥感数据源,对其进行几何校正、大气校正、图像裁剪等预处理后,结合同步观测的连云港赤潮监控区站位环境数据,采用二次滤波法、叶绿素a浓度法、波段比值法提取海州湾赤潮信息.[结果]2005年10月8日,连云港海域暴发面积约20.0 km2的赤潮;2006年5月20日,连云港海域赤潮处于消亡阶段;2006年10月6日,赤潮暴发规模大,面积约436.5 km2;2009年4月22日,连云港海域赤潮零星分布,面积约10.8 km2.[结论]该研究为

  18. The operational forecast system on red tide drift based on the C/S System Structure%基于C/S架构的业务化赤潮漂移扩散预报

    Institute of Scientific and Technical Information of China (English)

    杨静; 蔡文博; 李海

    2013-01-01

    以风场、三维海流场数值预报结果作为输入强迫,建立了赤潮漂移扩散数值预报模型,并开发了相应的软件模块.模块基于C/S(客户端/服务器端)架构,通过数值模拟技术以及GIS、Web Services等信息技术,实现“提交预报请求—数值模式计算—预报结果可视化—预报产品生成”自动化赤潮漂移与扩散预报工作流程.该预报模块具备数据预处理、人机交互参数输入、数值模式计算、预报结果可视化和预报产品制作功能.以长江口附近海域历史赤潮为例进行后报试验,预测了赤潮藻团在风与流场共同作用下的漂移路径变化,结果与实际监测情况一致.该模块的业务化应用能进一步完善现有的赤潮预报系统,将成为赤潮防灾减灾的有力工具.%Forced by numerical forecast results of Wind field and three-dimensional current, a red tide drift prediction model was established. The development of appropriate software modules, which is based on C/S (client /server) architecture, unifies the "forecast request - numerical simulation - results of visualization - the forecast products generated "automated red tide drift and spread forecasting process by the numerical technology GIS and Web Services. The forecast module is provided by data preprocessing, the input of human-computer interaction parameters, numerical calculations, results visualization and forecasting production function, Hindcast test of the history red tide near the Yangtze Delta is conducted to predict the drift path of the red tide algae group under the joint action of the wind and water current. The results are consistent with the actual monitoring data. The operational application of the module can further improve the existing red tide forecasting system, and will become a powerful tool for the red tide disaster prevention and mitigation.

  19. Retrieve of Red Tide Distributions from MODIS Data Based on the Characteristics of Water Spectrum%基于水体光谱特性的赤潮分布信息MODIS遥感提取

    Institute of Scientific and Technical Information of China (English)

    丘仲锋; 崔廷伟; 何宜军

    2011-01-01

    赤潮监测对于赤潮治理、预防,减少赤潮危害有着重要作用.通过分析东海赤潮多发区域实测遥感反射率曲线,比较赤潮水体与非赤潮水体的光谱特性差异,发展了一种针对MODIS传感器的赤潮水体分布信息遥感提取方法.应用实测资料对提取方法进行验证,发现在119组实测数据中,只有一组不能正确识别.将算法应用于MODIS卫星资料,对2005年4月4日东海部分海区进行赤潮水体信息提取,得到三个区域总面积约2000 km2的赤潮水体分布信息,赤潮水体提取结果与遥感提取的叶绿素a浓度有很好的对应关系,与实际观测记录对照大体吻合良好.研究表明本文的算法可有效地排除悬浮泥沙水体等干扰影响,确定可能发生赤潮的海区位置及提取海区大范围赤潮水体分布的信息.%After comparing the spectral differences between red tide water and normal water, we developed a method to retrieve red tide distributions from MODIS data based on the characteristics of red tide water spectrum. The authors used the 119 series of in situ observations to validate the method and found that only one observation has not been detected correctly. The authors then applied this method to MODIS data on April 4, 2005. In the research areas three locations of red tide water were apparently detected with the total areas about 2 000 km2. The retrieved red tide distributions are in good agreement with the distributions of high chlorophyll a concentrations. The research suggests that the method is available to eliminating the influence of suspended sediments and can be used to retrieve the locations and areas of red tide water.

  20. Research and mechanism on plant allelopathy inhibition marine red tide: A reviw%植物化感作用抑制海洋赤潮的研究与机理

    Institute of Scientific and Technical Information of China (English)

    边归国

    2013-01-01

    A fully introduce the terrestrial,freshwater aquatic,large algae and so on various plant allelopathy inhibit 19 species of marine red tide algae method,allelochemicals and inhibition mechanism.Preliminary analysis of the large algae and micro algae mutual inhibition,and plant allelopathy inhibition Marine red tide algae technology was discussed.%较全面地介绍了陆生、淡水水生、大型海藻等各种植物化感作用抑制19种海洋赤潮藻类的方法、化感物质和抑制机理,初步分析了大型海藻和微藻之间的相互抑制作用,并对植物化感作用抑制海洋赤潮藻类技术进行展望.

  1. Temporal and Spatial Distribution of Red Tide in Yangtze River Estuary and Adjacent Waters%长江口及其邻近海域赤潮时空分布研究

    Institute of Scientific and Technical Information of China (English)

    刘录三; 李子成; 周娟; 郑丙辉; 唐静亮

    2011-01-01

    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.%收集了1972~2009年长江口及其邻近海域(29°25'~32°00'N、124°00'E以西)所记载的赤潮事件,基于GIS软件平台,系统分析赤潮的时空分布规律,并绘制长江口及邻近海域赤潮分布图.分析表明:①近40年来,长江口及邻近海域赤潮发生多达174次,暴发面积〉1 000 km2的有25次.赤潮发生核心区集中在长江口外佘山附近、花鸟山-嵊山-枸杞附近、舟山附近及朱家尖东部海域,其发生频率呈明显上升趋势,2000年后尤为显著;②从发生月份看,该区域赤潮多发期集中在5、6月,其中5月发生次数占总次数的51%,6月占20%;③长江口及邻近海域的赤潮生物中,东海原甲藻、中肋骨条藻、具齿原甲藻及夜光藻占优势地位,发生次数分别为38次、35次、15次、10次,可以认为这4种藻类是该海域赤潮暴发的关键种.

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

    Directory of Open Access Journals (Sweden)

    S.-W. Chen

    2014-05-01

    Full Text Available 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.

  3. FIVE RED TIDE SPECIES IN GENUS PROROCENTRUM INCLUDING THE DESCRIPTION OF PROROCENTRUM DONGHAIENSE LU SP. NOV. FROM THE EAST CHINA SEA

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    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.

  4. FIVE RED TIDE SPECIES IN GENUS PROROCENTRUM INCLUDING THE DESCRIPTION OF PROROCENTRUM DONGHAIENSE LU SP. NOV. FROM THE EAST CHINA SEA

    Institute of Scientific and Technical Information of China (English)

    陆斗定; JeanetteGoebel

    2001-01-01

    A new planktonic dinoflagellate, Prorocentrum donghaiense I_a 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 pel'iflagellar area and the intercalary bands as seen by fight 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.

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

    Science.gov (United States)

    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.

  6. 甲藻赤潮与水体中营养盐的关系初探%Preliminary study on the rel ationship between dinoflagellate red tide and nutrients

    Institute of Scientific and Technical Information of China (English)

    林昱

    2001-01-01

    In an enclosed experimental system, which was conducted in the land-based tanks in Third Institute of Oceanography, SOA, Xiamen, we induced dinoflagellate red tides artificially without the effects of disturbance of salinity and water movement. There occurred red tides of Gymnodinium sp. and Prorocentum micans respectively in two enclosures of this experiment. The nutrient data examined in the forming and development processes of the red tides showed that the multiplication some dinoflagellates species of did not reguire a higher level of nutrient concentration in water column. But nutrient supply would affect the dinoflagellate red tide scale and its dominated species.%作者在国家海洋局第三海洋研究所的陆基水池中,应用围隔实验技术,排除了水动力、盐度等环境因子的变动性的干扰,人工诱发甲藻赤潮.在这个围隔实验的两个围隔体中,分别发生了一种裸甲藻(Gymnodinium sp.)和海洋原甲藻(Prorocentum micans)的赤潮.在赤潮发生和发展过程中所监测到的营养盐数据表明:有些甲藻增殖不一定需要水体中高营养盐;营养盐供给的多寡会导致甲藻赤潮优势种的差异和赤潮规模.

  7. Primary analysis on red tide of Akashiwo sanguinea in winter in Xiamen Sea%厦门海域一次冬季血红哈卡藻赤潮的初步分析

    Institute of Scientific and Technical Information of China (English)

    陈国斌

    2012-01-01

    According to the monitoring data of Akashiwo sanguinea red tide occurred in Xiamen Sea in January and February 2009,the characteristic of red tide,the relationships of environmental factors and the density of Akashiwo sanguinea were analyzed.The results showed that the red tide event was the earliest and the longest one in Xiamen Sea.Akashiwo sanguinea had more competitive advantages over Skeletonema costatum and had a strong adaptability to water temperature change during the red tide,and the reproduction could be simulated by higher salinity.Besides,Akashiwo sanguinea had more competitive advantages in inorganic phosphorus limited environment and was benefited by the high nitrogen.%本文根据2009年1—2月厦门海域一次冬季血红哈卡藻赤潮的调查数据,分析本次赤潮的变化特点,并对血红哈卡藻与环境因子的关系进行初步分析。结果表明:本次赤潮是厦门海域有记载的赤潮中,发生时间最早、持续时间最长的赤潮。赤潮中血红哈卡藻比中肋条藻更具竞争优势,对水温变化的适应性很强。盐度对血红哈卡藻的繁殖具有刺激作用。在无机磷限制环境中,血红哈卡藻更具竞争优势,而无机氮含量高有利于血红哈卡藻的生长。

  8. 赤潮相关因子的卫星遥感探测与赤潮预报的可行性探讨%Detection of Red Tide on Remotely Sensed Satellite Date and an Approach to Red Tide Forecast

    Institute of Scientific and Technical Information of China (English)

    陈晓翔; 邓孺孺; 何执兼; 柯栋; 李芳

    2001-01-01

    讨论遥感探测赤潮相关因子的技术方法以及现阶段遥感观测手段的不足之处,认为赤潮的监测和预报须依靠多层次的海洋观测系统和多学科的综合研究才能实现,其中,多层次的海洋观测手段是关键,建立有效的海洋综合观测系统是预报赤潮的必要条件(如正在建设中的珠江口、上海海洋立体观测示范技术系统),利用已有的综合技术实现赤潮的预报是完全可能的.%The method detecting red tide-related factors using remote sensing technology and the deficiency of the method used nowadays are discussed. It also points out, that the successful observation and prediction should rely on the multi-level marine observation systems and the integration of technology from various disciplines. In this process, multi-level marine observation is the most important technology, and the establishment of effective oceanic integrated observation system such as the ones in the Pearl River Estuary and the Shanghai-East China Sea, is an essential prerequisites. With the integrated technology referred above, it is possible to realize the prediction of red tide.

  9. 福建沿海近10a赤潮基本特征分析%Analysis on Characteristics of Red Tide in Fujian Coastal Waters During the Last 10 Years

    Institute of Scientific and Technical Information of China (English)

    李雪丁

    2012-01-01

    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: ①Outbreaks 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.②There 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. ③ 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.%收集整理了自2001-2010年近lOa的福建沿海161起赤潮事件,通过统计的方法综合分析.结果表明福建沿海赤潮在时间和空间上具有以下特征:①时间分布上,赤潮主要发生在4-9月,高发期为5-6月,大部分赤潮的持续时间为2-4d,且发生面积在50km2以下.近年来赤潮初发期的

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

    Science.gov (United States)

    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. Gene expression in Florida red tide dinoflagellate Karenia brevis: analysis of an expressed sequence tag library and development of DNA microarray.

    Science.gov (United States)

    Lidie, Kristy B; Ryan, James C; Barbier, Michele; Van Dolah, Frances M

    2005-01-01

    Karenia brevis (Davis) is the dinoflagellate responsible for nearly annual red tides in the Gulf of Mexico. Although the mechanisms regulating the growth and toxicity of this problematic organism are of considerable interest, little information is available on its molecular biology. We therefore constructed a complementary DNA library from which to gain insight into its expressed genome and to develop tools for studying its gene expression. Large-scale sequencing yielded 7001 high-quality expressed sequence tags (ESTs), which clustered into 5280 unique gene groups. The vast majority of genes expressed fell into a low-abundance class, with the highest expressed gene accounting for only 1% of the total ESTs. Approximately 29% of genes were found to have similarity to known sequences in other organisms after BLAST similarity comparisons to the GenBank public protein database using a cutoff of P < 10e(-4). We identified for the first time in a dinoflagellate a suite of conserved eukaryotic genes involved in cell cycle control, intracellular signaling, and the transcription and translation machinery. At least 40% of gene clusters displayed single nucleotide polymorphisms, suggesting the presence of multiple gene copies. The average GC content of ESTs was 51%, with a slight preference for G or C in the third codon position (53.5%). The ESTs were used to develop an oligonucleotide microarray containing 4629 unique features and 3462 replicate probes. Microarray labeling has been optimized, and the microarray has been validated for probe specificity and reproducibility. This is the first information to be developed on the expressed genome of K. brevis and provides the basis from which to begin functional genomic studies on this harmful algal bloom species. PMID:15976935

  12. OUTBREAK OF SKELETONEMA COSTATUM RED TIDE AND ITS RELATIONS TO ENVIRONMENTAL FACTORS IN JIAOZHOU BAY%胶州湾中肋骨条藻赤潮与环境因子的关系

    Institute of Scientific and Technical Information of China (English)

    霍文毅; 俞志明; 邹景忠; 宋秀贤; 郝建华

    2001-01-01

    1998年7月3—8日胶州湾女姑山增养殖海域发生一次中肋骨条藻(Skeletonema costatum)赤潮,对该次赤潮生消全过程环境因子变化的监测分析表明:该养殖海域表层水体溶解态无机氮、无机磷、可溶性铁和锰含量高,为赤潮的发生提供了必需的营养基础;6月30日—7月1日较强的降雨过程使水体在以后两天中形成了高温、低盐、富营养的环境,有利于中肋骨条藻的快速增殖并直接导致了赤潮的爆发;7月3—8日天气持续的高温和静风使赤潮得以维持,随后磷、硅的耗尽使赤潮逐步走向消亡。应用相关分析和主成分分析,研究了赤潮与环境因子的关系。结果表明,影响本次赤潮的重要环境因子有:盐度、水温、硅酸盐、磷酸盐。%A Skeletonema costatum red tide occurred on July 3—8, 1998 in Jiaozhou Bay. Variations of ecological factors and their influence upon red tide organisms were determined. Relatively high contents of nutrients, iron and manganese were responsible for the growth of Skeletonema costatum. The outbreak of the Skeletonema costatum red tide has a close relationship with the strong rain on June 30 and July 1, 1998. After the rain, warm, low-salinity and eutrophic water resulted in the rapid proliferation of Skeletonema costatum. In terms of the nutrients structure, compared with TIN (total inorganic nitrogen), the concentration of silicate and phosphate were relatively deficient. At the developing stage, the concentration of various nutrients and iron in surface water as well as TIN were declining due to the declination of nitrate. Among the three forms of TIN, it is possible that Skeletonema costatum preferred to absorb nitrate. At the blooming stage, the exhaustion of phosphate and silicate led to the death of Skeletonema costatum and disappearance of red tide. After the bloom disappeared, the contents of TIN and silicate returned rapidly to normal, but the

  13. Remarkable difference in paralytic shellfish poisoning toxin distribution in tissues of pen shell atrina pectinata exposed to toxic red tide bloom

    International Nuclear Information System (INIS)

    tissues and shellfish body lengths or age were also assessed and were found to be uncorrelated. Note worthily, STX was the only toxin detected in the abductor muscle suggesting a bioconversion of all other toxin derivatives. Based from the findings, abductor muscle of A. pectinata accumulates minimal toxicity level, thus removal of the part from the whole body for marketing suggests safe human consumption despite toxic red tide episodes, provided that strict quality assurance on the said product is applied. (author)

  14. Research on Adaptive Variable Structure Control for Bi-ological Model of Red Tide%赤潮生物种群模型的自适应变结构控制器设计

    Institute of Scientific and Technical Information of China (English)

    雷小春

    2016-01-01

    【目的】为进一步改进有害藻和有益藻的消长控制模型,更好控制有害藻的发生,避免其所造成的危害。【方法】假设赤潮有害藻密度可测,有益藻密度不可测,在有害藻和有益藻密度模型正则化的基础上,设计神经网络观测器来估计有益藻对应的变量;然后,设计变结构控制使有害藻浓度减少而有益藻浓度增大,最终达到稳定状态。【结果】仿真分析结果显示,有害藻和有益藻持续在稳定的状态。【结论】变结构控制器的设计合理有效。%Objective]In order to overcome the weakness of traditional treatment methods of red tide(including physical method and chemical method),biological treatment technique was ex-plored,where the relationship among creature competition,biological inhibition and biological predation was evaluated.Introducing beneficial creature in the area of red tide could inhibit the eruption of red-tide algae,and reduce the occurrence of red-tide algae and its damage.[Methods]In the paper,we assumed that the density of harmful algae could be measured whereas the den-sity of beneficial algae could not be measured.Based on the regularization of the density model of harmful algae and beneficial algae,neural network viewer was designed to estimate corre-sponding changes of beneficial algae.Then,a variable structure control was designed to reduce the density of harmful algae and increase that of beneficial algae,and finally to reach a steady state.[Results]Simulation results of an example illustrated the effectiveness of the proposed method.[Conclusion]The designed variable structure control is effective.

  15. Primary study on the transparency as a forecast parameter of red tide%透明度作为赤潮预警监测参数的初步研究

    Institute of Scientific and Technical Information of China (English)

    矫晓阳

    2001-01-01

    The resea rch data show that the transparency has a definite relationship with the density and species of phytoplankton under general condition. The transparency is high in the low phytoplankton density, and low in the high. It is suggested that the transparency may be the parameter to forecast the red tide in test. The transparency data 1.6 m should be the standard figure for the forecast of the red tide.%调查实验数据显示,在一定条件下,透明度与浮游植物密度和种类之间有着一定的 关系。浮游植物密度低时透明度高,浮游植物密度高时透明度低。认为可以尝试使用透明度 作为赤潮预警监测或短期预报的参数。透明度值1.6 m可以作为赤潮预警的标准值进行试点 。

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

    Energy Technology Data Exchange (ETDEWEB)

    Bentlin, Fabrina R.S. [Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves 9500, 91501.970 Porto Alegre, RS (Brazil); Santos, Clarissa M.M. dos; Flores, Erico M.M. [Departamento de Quimica Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS (Brazil); Pozebon, Dirce, E-mail: dircepoz@iq.ufrgs.br [Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves 9500, 91501.970 Porto Alegre, RS (Brazil)

    2012-01-13

    Highlights: Black-Right-Pointing-Pointer Ultrasound was investigated and applied for red wine samples preparation. Black-Right-Pointing-Pointer Aliquots of 50 {mu}L of sample were nebulized and transported to plasma. Black-Right-Pointing-Pointer FI and pneumatic nebulization/aerosol desolvation were used. Black-Right-Pointing-Pointer LODs of the ICP-MS method for lanthanides determination were at ng L{sup -1} level. Black-Right-Pointing-Pointer Lanthanides concentration allowed red wines classification. - Abstract: This paper deals with the determination of the fourteen naturally occurring elements of the lanthanide series in red wine. Ultrasound (US) was used for sample preparation prior lanthanides determination using ICP-MS. Flow injection (FI) and pneumatic nebulization/aerosol desolvation were used for nebulization of aliquots of 50 {mu}L of sample and its subsequent transportation to plasma. Sample preparation procedures, matrix interference and time of sonication were evaluated. Better results for lanthanides in red wine were obtained by sonication with US probe for 90 s and sample 10-fold diluted. The limits of detection of La, Ce, Nd, Sm, Gd, Pr, Eu, Tb, Dy, Ho, Er, Tm, Lu and Yb were 6.57, 10.8, 9.97, 9.38, 2.71, 1.29, 1.22, 0.52, 2.35, 0.96, 2.30, 0.45, 0.24 and 1.35 ng L{sup -1}, respectively. Red wines of different varieties from three countries of South America were discriminated according to the country of origin by means of multivariate analysis of lanthanides concentration.

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

    International Nuclear Information System (INIS)

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

  18. Europa Tide Movie

    Science.gov (United States)

    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.

  19. Aquatic plant allelopathy emergency disposal of red tide and freshwater algal blooms%水生植物化感作用应急处置海洋赤潮和淡水水华

    Institute of Scientific and Technical Information of China (English)

    边归国

    2012-01-01

    In recent years, Allelopathy is becoming the new technology to control algae outbreaks. According to the research results at home and abroad, focus on the aquatic plant allelopathy, allelopathic algal material, algae emergency response methods, the red tide and algal blooms in freshwater emergency response and mechanism are reviewed, and the future development are to be Looking.%近年来,植物化感作用逐渐成为控制藻类暴发的一种新技术。根据国内外的研究成果,着重从水生植物化感作用、化感抑藻物质、应急处置藻类方法、海洋赤潮和淡水水华的应急处置及机理进行评述,并对该技术今后的发展予以展望。

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

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Reed F. [Emerging Viral Pathogens Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, MD 21702 (United States); Hammoud, Dima A. [Center for Infectious Disease Imaging, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD 20892 (United States); Lackemeyer, Matthew G.; Yellayi, Srikanth [Integrated Research Facility, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, MD 21702 (United States); Solomon, Jeffrey [Center for Infectious Disease Imaging, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD 20892 (United States); Bohannon, Jordan K.; Janosko, Krisztina B.; Jett, Catherine; Cooper, Kurt [Integrated Research Facility, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, MD 21702 (United States); Blaney, Joseph E. [Office of the Scientific Director, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892 (United States); Jahrling, Peter B. [Emerging Viral Pathogens Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, MD 21702 (United States); Integrated Research Facility, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Frederick, MD 21702 (United States)

    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.

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

    International Nuclear Information System (INIS)

    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. - 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

  2. 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

    KAUST Repository

    Brindley, H.

    2015-10-20

    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.

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

    Science.gov (United States)

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

    2015-07-01

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

  4. Application of synchrotron radiation for measurement of iron red-ox speciation in atmospherically processed aerosols

    Directory of Open Access Journals (Sweden)

    B. J. Majestic

    2007-01-01

    Full Text Available In this study, ambient atmospheric particulate matter (PM samples were collected using a size-resolved impactor sampler from three urban sites. The purpose of this study is to gain a better understanding of transformations of aerosol-bound iron as it is processed in the atmosphere. Thus, the aerosol samples were artificially aged to represent long-term transport (10 to 40 days or short-term transport (1 to 10 days and were measured for iron at several time points. At each time point, iron was measured in each size fraction using three different techniques; 1 inductively coupled plasma-mass spectrometry (ICPMS for total iron, 2 x-ray absorbance near edge structure (XANES spectroscopy for the measurement of total Fe(II and Fe(III, and 3 a wet-chemical method to measure soluble Fe(II and Fe(III. Prior to aging, the XANES spectroscopy results show that a majority (>60% for each size fraction of the total iron in the PM is in the form of Fe(III. Fe(III was shown to be a significant fraction of the soluble iron (sometimes > 50%, but the relative significance of Fe(III was found to vary depending on the site. Overall, the total soluble iron depended on the sampling site, but values ranged from less than 1% up to about 18% of the total iron. Over the course of the 40 day aging period, we found moderate changes in the relative Fe(II/Fe(III content. A slight increase was noted in the coarse (>2.5 μm fraction and a slight decrease in the 0.25 to 0.5 μm fraction. The soluble fraction generally showed (excepting one day a decrease of soluble Fe(II prior to 10 days of aging, followed by a relatively constant concentration. In the short-term transport condition, we found that the sub-micron fraction of soluble Fe(II spikes at 1 to 3 days of aging, then decreases to near the initial value at around 6 to 10 days. Very little change in soluble Fe(II was observed in the super-micron fraction. These results show that changes in the soluble iron fraction occur

  5. Forecast of Red Tide in the South China Sea by Using the Variation Trend of Hydrological and Meteorological Factors%利用水文、气象要素因子的变化趋势预测南海区赤潮的发生

    Institute of Scientific and Technical Information of China (English)

    张俊峰; 蒋跃进; 白毅平; 俞建良; 庞海龙; 邓文君; 李华健; 吴迪生; 赵雪; 陈惠君

    2006-01-01

    Many studies point out that weather conditions involving temperature, wind power, monsoon transform, air pressure, sea condition, tide, ocean current, salinity, eutrophic environment and so on are key factors causing Red Tide [1]. In the red tide high frequency areas of the South China Sea, the eutrophic environment of sea water has already existed, so the key elements such as meteorological and hydrological conditions play an importance role in the occurrence of red tide. The atmospheric circulation maintenance and variation decide whether meteorological phenomena, and hydrological key elements stabilize or change. Moreover,the red tide organisms' breeding from the initial stage to the blooming reproduction stage,until reaching the biological density of the red tide, generally takes 4 - 5 days. In the paper, the red tide examples are analyzed in the past 10 years, and the weather circulation situation and hydro-meteorological key elements of it are counted to find the previous circulation mode and bring out important factors inducing the blooming of red tide. The predicted result in 2003 according to this method was satisfactory.%有些文献指出:"赤潮发生起因因种而异,但大体上气候气象条件诸如温度、风力、风向,季风转换、气压等;海况、潮汐、流等以及海水的理化特征,如盐度、营养元素等,这些皆会成为某种赤潮爆发的因子或诱导因素 [1]".根据赤潮监控区监测资料分析:在南海赤潮多发区,海水富营养化条件已经具备,因此气象、水文要素条件就成为赤潮爆发的重要启动因子,而天气环流的维持与变化决定了气象、水文要素因子的稳定与变化,再根据赤潮生物培养试验,从初期繁殖到后期的爆发性繁殖,直至达到赤潮生物密度,这一过程一般都需要4~5 d的时间.针对这一现象,通过对近10 a的赤潮发生个例进行统计分析,统计其生成前期的天气环流形势和水文气象要素,分析

  6. Application of synchrotron radiation for measurement of iron red-ox speciation in atmospherically processed aerosols

    Directory of Open Access Journals (Sweden)

    B. J. Majestic

    2007-01-01

    Full Text Available In this study, ambient atmospheric particulate matter samples were collected using a size-resolved impactor sampler from three urban sites. The purpose of this study is to gain a better understanding of transformations of aerosol-bound iron as it is processed in the atmosphere. Thus, the aerosol samples were artificially aged to represent long-term transport (10 to 40 days or short-term transport (1 to 10 days and were measured for iron at several time points. At each time point, iron was measured in each size fraction using three different techniques; 1 inductively coupled plasma-mass spectrometry (ICPMS for total iron, 2 x-ray absorbance near edge structure (XANES spectroscopy for the measurement of total Fe(II and Fe(III, and 3 a wet-chemical method to measure soluble Fe(II and Fe(III. Prior to aging, the XANES spectroscopy results show that a majority (>60% for each size fraction of the total iron in the PM is in the form of Fe(III. Fe(III was shown to be a significant fraction of the soluble iron (sometimes >50%, but the relative significance of Fe(III was found to vary depending on the site. Overall, the total soluble iron depended on the sampling site, but values ranged from less than 1% up to about 20% of the total iron. Over the course of the 40 day aging period, we found moderate changes in the relative Fe(II/Fe(III content. A slight increase was noted in the coarse (>2.5 µm fraction and a slight decrease in the 0.25 to 0.5 µm fraction. The soluble fraction generally showed (excepting one day a decrease of soluble Fe(II prior to 10 days of aging, followed by a relatively constant concentration. In the short-term transport condition, we found that the sub-micron fraction of soluble Fe(II spikes at 1 to 3 days of aging, then decreases to near the initial value at around 6 to 10 days. Very little change in soluble Fe(II was observed in the super-micron fraction.

  7. TIDE-TSUNAMI INTERACTIONS

    Directory of Open Access Journals (Sweden)

    Zygmunt Kowalik

    2006-01-01

    Full Text Available In this paper we investigate important dynamics defining tsunami enhancement in the coastal regions and related to interaction with tides. Observations and computations of the Indian Ocean Tsunami usually show amplifications of the tsunami in the near-shore regions due to water shoaling. Additionally, numerous observations depicted quite long ringing of tsunami oscillations in the coastal regions, suggesting either local resonance or the local trapping of the tsunami energy. In the real ocean, the short-period tsunami wave rides on the longer-period tides. The question is whether these two waves can be superposed linearly for the purpose of determining the resulting sea surface height (SSH or rather in the shallow water they interact nonlinearly, enhancing/reducing the total sea level and currents. Since the near–shore bathymetry is important for the run-up computation, Weisz and Winter (2005 demonstrated that the changes of depth caused by tides should not be neglected in tsunami run-up considerations. On the other hand, we hypothesize that much more significant effect of the tsunami-tide interaction should be observed through the tidal and tsunami currents. In order to test this hypothesis we apply a simple set of 1-D equations of motion and continuity to demonstrate the dynamics of tsunami and tide interaction in the vicinity of the shelf break for two coastal domains: shallow waters of an elongated inlet and narrow shelf typical for deep waters of the Gulf of Alaska.

  8. Red Tide and Paralytic Shellfish Poisoning

    Science.gov (United States)

    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)

  9. Florida Red Tide Perception: Residents versus Tourists

    OpenAIRE

    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...

  10. Tides and deltaic morphodynamics

    Science.gov (United States)

    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

    Science.gov (United States)

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

    OpenAIRE

    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....

  13. Strong Tides in 1964 and 1982

    Institute of Scientific and Technical Information of China (English)

    Dianyou Chen; Xuexiang Yang; Qiyuan Qiao

    2003-01-01

    The differential rotation between solid and fluid caused by tidal force can explain a 1500 to 1800-year cycle of the climate change. Strong tide increases the vertical and horizontal mixing of water in ocean by drawing the cold Pacific water from the depths to the surface (or by making the warm water flow from the West Pacific to the East as well as from the North to the South). It cools or warms the atmosphere above and makes La Nina or El Nino occur in the whole world. Astronomical data have shown that strong tide is often associated with El Nino events. Volcanic activities at submarine are also controlled by strong tide. Volcanic activities can also draw warm water from the depths to the surface in the Pacific and volcanic ash can keep out sunlight, which is the most important external forcing factor for El Nino. If volcanic ash reaches into the stratosphere, finer aerosols will spread throughout the globe during a few months and will float in it for one to three years to weaken the sun's direct radiation to the areas. It is one of the factors to postpone EI Nino just like the process of solar eclipse.

  14. Astronomical tides and earthquakes

    Science.gov (United States)

    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.

  15. Allelopathic interactions between the red-tide causative dinoflagellate Prorocentrum donghaiense and the diatom Phaeodactylum tricornutum* This study was supported by the Natural Science Foundation of China-Guangdong Province Joint Key Project (U1133003 Science Technology Planning Project of Guangdong Province (2012B020307009 Open Fund from Key Laboratory of Aquatic Eutrophication Control of Harmful Algal Blooms of Guangdong Higher Education Institutes Open Fund from Key Laboratory of Microbial Resources Collection Preservation Ministry of Agriculture.

    Directory of Open Access Journals (Sweden)

    Zhuoping Cai

    2014-06-01

    Full Text Available The interactions between the red-tide causing dinoflagellate Prorocentrum donghaiense and the marine diatom Phaeodactylum tricornutum were investigated using a co-culture experiment and an enriched culture filtrate experiment. The results showed that when the two microalgae were cultured together with different initial cell densities, the growth of one species was basically suppressed by the other one. In addition, the enriched culture filtrates of one species had generally inhibitory effects on the other one. Our result inferred that P. donghaiense and P. tricornutum would interfere with each other mainly by releasing allelochemicals into the culture medium, and that the degree of allelopathic effects was dependent on the initial cell densities and growth phases. The allelopathic interactions between microalgal species may contribute to the formation and succession of red tides.

  16. Allelopathic interactions between the red-tide causative dinoflagellate Prorocentrum donghaiense and the diatom Phaeodactylum tricornutum* This study was supported by the Natural Science Foundation of China-Guangdong Province Joint Key Project (U1133003) Science Technology Planning Project of Guangdong Province (2012B020307009) Open Fund from Key Laboratory of Aquatic Eutrophication Control of Harmful Algal Blooms of Guangdong Higher Education Institutes Open Fund from Key Laboratory of Microbial Resources Collection Preservation Ministry of Agriculture.

    OpenAIRE

    Zhuoping Cai; Honghui Zhu; Shunshan Duan

    2014-01-01

    The interactions between the red-tide causing dinoflagellate Prorocentrum donghaiense and the marine diatom Phaeodactylum tricornutum were investigated using a co-culture experiment and an enriched culture filtrate experiment. The results showed that when the two microalgae were cultured together with different initial cell densities, the growth of one species was basically suppressed by the other one. In addition, the enriched culture filtrates of one species had generally inhibitory effec...

  17. EFFECTS OF TEMPERATURE, SALINITY, LIGHT AND pH ON THE GROWTH OF RED TIDE ORG ANISMS PROROCENTRUM MICANS%温度、盐度、光照强度和pH对海洋原甲藻增长的效应

    Institute of Scientific and Technical Information of China (English)

    王正方; 张庆; 吕海燕

    2001-01-01

    采用微量移液稀释法对海洋原甲藻进行无菌培养 ,以研究温度、盐度、光照强度和pH对海洋原甲藻增长的效应。结果表明,海洋原甲藻最大 增殖速率发生在温度为(25±1)℃、盐度为31、光照强度为3000lx、pH为8.0的环境条件下。 海洋原甲藻在温度18-28℃、盐度为25-34、光照强度为1000-6500lx、pH为7.5-8.3范围 内适宜生长。这一结果与观测到的海洋原甲藻赤潮发生时环境条件相近,其中温度的效应最 为明显。%Prorocentrum micans Ehrenb which has cau sed heavy red tides in the costal sea area of China was placed in aseptic clonal culture by micropipette washing. Experiments showed that the growth of the red tide organism P. micans required suitable environment like temperature, sali nity, irradiance, pH. and other chemical factors. P. micans could grow from 18℃ to 28℃, 25 to 34 salinity, irradiance from 1000lx to 6500lx and 7.5 to 8.3 pH. The highest growth rate was observed at temperature (25±1)℃,salinity 31, irradiance 3000lx and pH8.0. The results and field observations indicated that the development of the Prorocentrum micans red tide is strongly dependent on the temperature.

  18. Effects of Mochromatic and Cmbination Spectra of LED on the Gowth of the Skeletonema costatum in Red Tide%LED单色光谱及复合光谱对赤潮优势种中肋骨条藻生长的作用

    Institute of Scientific and Technical Information of China (English)

    苗洪利; 孙丽娜; 田庆震; 周晓光; 王晶

    2011-01-01

    以赤潮优势种中肋骨条藻(Skeletonema costatum)为研究对象,荧光灯和自制LED( light-emitting diode)控制灯为光源,研究不同LED单色光谱及复合光谱(蓝光,绿光,红光,白光,蓝红光,绿红光)对中肋骨条藻生长的作用.实验结果表明,在相同的光合有效量子通量密度条件下,对于单色光,中肋骨条藻在蓝光下生长较快,红光次之,在绿光下生长最慢;对于复合光,中肋骨条藻在荧光灯下生长最快,而在蓝红光下生长略高于在绿红光下生长.各光源下中肋骨条藻生长速率的顺序为:荧光灯>蓝红光LED>绿红光LED>蓝光LED>红光LED>绿光LED.通过比较在不同光照条件下中肋骨条藻的生长速率,表明不同光谱对中肋骨条藻生长的作用不同.%With the dominant species of red tide Skeletonema costatum as the research object, fluorescent lamp and self-control LED (light-emitting diode) as light sources, the Skeletonema costatum was cultivat ed to investigate the effect of the different monochromatic and combination spectra of LED (blue, red, green, white, blue and red, green and red) on the growth of Skeletonema costatum. It was concluded that in the same photosynthetic available quantum flux density, for monochromatic light, cell growth rate was greater in blue light than in green or red light; for combined sources, Skeletonema costatum growth with the red and blue light slightly higher than with the green and red light, while white light has the best effi ciency. The growth rate of Skeletonema costatum showed that: Fluorescent lamp>red and blue LED>red and green LED>blue LED> red LED > green LED. For different light sources, the results of the growth rates of Skeletonema costatum which indicated that different spectra had important effect on the growth of Skeletonema costatum.

  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

    Science.gov (United States)

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

    Science.gov (United States)

    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

  1. On a rising tide

    International Nuclear Information System (INIS)

    The world's oceans contain an enormous potential source of energy. What is surprising is how little this potential is exploited. Now however researchers are beginning to make progress in pursuit of a renewable energy that has been elusive. So far two major sites that can sustain tidal power projects have been identified in India: the Gulf of Bombay and the Gulf of Kutch with a mean tidal range of five and seven metres respectively. They have a combined potential of 9700 MW. The environmental impacts of any tidal power scheme will depend mainly on local geography. Local tides changed only slightly as a result of the La Rance barrage, and the environmental impact has been negligible, but other sites could face more serious problems. (author)

  2. LAGEOS Sensitivity to Ocean Tides

    OpenAIRE

    Sośnica Krzysztof

    2015-01-01

    Satellite Laser Ranging (SLR) to LAGEOS has a remarkable contribution to high-precise geodesy and geodynamics through deriving and validating various global geophysical models. This paper validates ocean tide models based on the analysis of satellite altimetry data, coastal tide gauges, and hydrodynamic data, i.e., CSR3.0, TOPEX4.0, CSR4.0A, FES2004, GOT00.2, and the CSRC Schwiderski model. LAGEOS orbits and SLR observation residuals from solutions based on different ocean tide models are com...

  3. Tides in Giant Planets

    Science.gov (United States)

    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

  4. Tides and Modern Geodesy

    Science.gov (United States)

    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.

  5. Dynamical Tides Simplified

    CERN Document Server

    Kushnir, Doron; Kollmeier, Juna A; Waldman, Roni

    2016-01-01

    Zahn (1975) first put forward and calculated in detail the torque experienced by stars in close binary systems due to dynamical tides. His widely used formula for stars with radiative envelopes and convective cores is expressed in terms of the stellar radius, even though the torque is actually being applied to the convective core at the core radius. This results in a large prefactor, which is very sensitive to the global properties of the star, that multiplies the torque. This large factor is compensated by a very small multiplicative factor, $E_{2}$. Although this is mathematically accurate, depending on the application this can lead to significant errors. The problem is even more severe, since the calculation of $E_{2}$ itself is non-trivial, and different authors have obtained inconsistent values of $E_{2}$. Moreover, many codes (e.g. BSE, StarTrack, MESA) interpolate (and sometimes extrapolate) a fit of $E_{2}$ values to the stellar mass, often in regimes where this is not sound practice. We review previo...

  6. Re-examining Galileo's theory of tides.

    Science.gov (United States)

    Palmieri, P.

    1998-11-01

    This study expounds the model of the Earth tides by Galileo Galilei in all its amazing complexity by bringing to light its completely forgotten vision of the flux and reflux of the sea as a wave-like phenomenon and by reassessing Galileo's claim that this model was a physical proof of the double motion of the Earth as postulated by Copernicus, namely, its diurnal rotation about its polar axis and its annual revolution around the Sun. The study is organized in the chapters: (1) Galileo's tide-generating acceleration: the woad-grindstone model; composition of speeds and relativity; tide-generating acceleration as a historiographical stumbling block. (2) Newton's tide-generating force: Newton's dynamic model; asymmetric tide-generating force and asymmetric tide periods. (3) Galileo's oscillatory model: a simple oscillating system; the laws of basins and superposition of waves. (4) The "warping" of history: Galileo's claim that tides prove Copernicus; Galileo's notions on bodies that move around a centre; tide equations - the quasi-Galilean term; tides in a non-Newtonian universe. (5) Simulate the wind and the sea: comets and winds; rotating buckets and the terrestrial atmosphere; tide experiments - artificial vessels and tide-machines. (6) Celestial wheel clock: monthly and annual periodicities; the celestial balance-stick regulator. (7) Moon and waves: lunar trepidations and tides - a new research programme; a single great wave.

  7. Tides in asynchronous binary systems

    OpenAIRE

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

    2006-01-01

    Stellar oscillations are excited in non-synchronously rotating stars in binary systems due to the tidal forces. Tangential components of the tides can drive a shear flow which behaves as a differentially forced rotating structure in a stratified outer medium. In this paper we show that our single-layer approximation for the calculation of the forced oscillations yields results that are consistent with the predictions for the synchronization timescales in circular orbits. In addition, calibrat...

  8. High tide in the Delta

    International Nuclear Information System (INIS)

    This inaugural speech takes a closer look at the relation of the Netherlands with water and sea. The author pleas for better connections of land and water and better connections of fresh and salt water. The oration discusses the influence of man on the climate, recent discoveries in the field of climate, urgency in the field of energy, opportunities for high tide protection in the Netherlands and plans for filling the new chair

  9. Weight, gravitation, inertia, and tides

    Science.gov (United States)

    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.

  10. High-tide habitat choice : insights from modelling roost selection by shorebirds around a tropical bay

    NARCIS (Netherlands)

    Rogers, Danny I.; Battley, Phil F.; Piersma, Theunis; Van Gils, Jan A.; Rogers, Ken G.

    2006-01-01

    High tides force shorebirds from intertidal feeding areas to sites known as roosts. We investigated the roost selection of great knots, Calidris tenuirostris, and red knots, Calidris canutus, on a tropical coastline in northwestern Australia, assessing several roost attributes and recording the freq

  11. 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

    Science.gov (United States)

    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

  12. Barometric tides from ECMWF operational analyses

    Directory of Open Access Journals (Sweden)

    R. D. Ray

    Full Text Available The solar diurnal and semidiurnal tidal oscillations in surface pressure are extracted from 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 et al. (1997. The resulting tides are compared with a "ground truth" tide data set, a compilation of well-determined tide estimates deduced from many long time series of station barometer measurements. These comparisons show that the ECMWF (analysis 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 side-lines. This complicates the development of a simple empirical model that can characterize the full temporal variability of the tides.

    Key words. Meteorology and atmospheric dynamics (waves and tides

  13. Atmospheric tides in Gale Crater, Mars

    Science.gov (United States)

    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.

  14. Tides, the PIG, and 'warm' water

    International Nuclear Information System (INIS)

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

  15. MST radar detection of middle atmosphere tides

    Science.gov (United States)

    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.

  16. Organic aerosols

    International Nuclear Information System (INIS)

    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

  17. Marine aerosols

    OpenAIRE

    Saltzman, Es

    2009-01-01

    The aerosol over the world oceans plays an important role in determining the physical and chemical characteristics of the Earth's atmosphere and its interactions with the climate system. The oceans contribute to the aerosols in the overlying atmosphere by the production and emission of aerosol particles and precursor gases. The marine aerosol, in turn, influences the biogeochemistry of the surface ocean through long distance transport and deposition of terrestrial and marine-derived nutrients...

  18. Thermal Tides in Fluid Extrasolar Planets

    CERN Document Server

    Arras, Phil

    2009-01-01

    Asynchronous rotation and orbital eccentricity lead to time-dependent irradiation of the close-in gas giant exoplanets -- the hot Jupiters. This time-dependent surface heating gives rise to fluid motions which propagate throughout the planet. We investigate the ability of this "thermal tide" to produce a quadrupole moment which can couple to the stellar gravitational tidal force. While previous investigations discussed planets with solid surfaces, here we focus on entirely fluid planets in order to understand gas giants with small cores. The Coriolis force, thermal diffusion and self-gravity of the perturbations are ignored for simplicity. First, we examine the response to thermal forcing through analytic solutions of the fluid equations which treat the forcing frequency as a small parameter. In the "equilibrium tide" limit of zero frequency, fluid motion is present but does not induce a quadrupole moment. In the next approximation, finite frequency corrections to the equilibrium tide do lead to a nonzero qua...

  19. Thermal Tides in Short Period Exoplanets

    CERN Document Server

    Arras, Phil

    2009-01-01

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

  20. Nonlinear Tides in Close Binary Systems

    CERN Document Server

    Weinberg, Nevin N; Quataert, Eliot; Burkart, Josh

    2011-01-01

    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 effects: three-mode nonlinear interactions and nonlinear excitation of modes by the time-varying gravitational potential of the companion. This paper presents the formalism for studying nonlinear tides and studies the nonlinear stability of the linear tidal flow. Although the formalism is applicable to binaries containing stars, planets, or compact objects, we focus on solar type stars with stellar or planetary companions. Our primary results include: (1) The linear tidal solution often used in studies of binary evolution is unstable over much of the parameter space in which it is employed. More specifically, resonantly excited gravity waves are unstable to parametric resonance for companion masses M' > 10-100 M_Earth at orbital periods P = 1-10 days. The nearly static equilibrium tide is, however, parametrically s...

  1. Arctic tides from GPS on sea ice

    DEFF Research Database (Denmark)

    Kildegaard Rose, Stine; Skourup, Henriette; Forsberg, René

    The presence of sea-ice in the Arctic Ocean plays a significant role in the Arctic climate. Sea ice dampens the ocean tide amplitude with the result that global tidal models which use only astronomical data perform less accurately in the polar regions. This study presents a kinematic processing of...... Global Positioning System (GPS) buoys placed on sea-ice at five different sites north of Greenland for the study of sea level height and tidal analysis to improve tidal models in the Central Arctic. The GPS measurements are compared with the Arctic tidal model AOTIM-5, which assimilates tide-gauges and...

  2. Sea level reconstruction from satellite altimetry and tide gauge data

    OpenAIRE

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

    2012-01-01

    Ocean satellite altimetry has provided global sets of sea level data for the last two decades, allowing determination of spatial patterns in global sea level. For reconstructions going back further than this period, tide gauge data can be used as a proxy. We examine different methods of combining satellite altimetry and tide gauge data using optimal weighting of tide gauge data, linear regression and EOFs, including automatic quality checks of the tide gauge time series. We attempt to augment...

  3. Shallow-water loading tides in Japan from superconducting gravimetry

    DEFF Research Database (Denmark)

    Khan, Shfaqat Abbas; Hoyer, J.L.

    2004-01-01

    Gravity observations from superconducting gravimeters are used to observe loading effects from shallow-water tides on the Japanese cast and west coasts. Non-linear third-diurnal and higher-frequency shallow-water tides are identified in the tide-gauge observations from these coastal areas. The mo...

  4. On tides in the strait of Messina

    International Nuclear Information System (INIS)

    A classical measurement of tides in the Messina strait made by Vercelli (1922-1923) is described. As Defant studied the same data with a linear barotropic model, a baroclinic, nonlinear theory is discussed. Some model equations are then discussed. (author)

  5. Nonlinear Tides in Close Binary Systems

    Science.gov (United States)

    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 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 standard three

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

    CERN Document Server

    Kopp, Robert E

    2013-01-01

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

  7. Numerical Simulation of Barotropic Tides around Taiwan

    Directory of Open Access Journals (Sweden)

    Chih-Kai Hu

    2010-01-01

    Full Text Available A _ 2-D barotropic tide model was used to examine the characteristics of barotropic tides and to improve the accuracy of predicting tidal sea levels and currents in the seas around Taiwan. The form ratio suggests that tides are predominantly semidiurnal in the northern reaches of the Taiwan Strait and mixed of diurnal and semidiurnal elsewhere around Taiwan. When the dominant M2 wave enters the Strait from the north, its amplitude is magnified to ~2 m in the middle, and then decreases rapidly toward the south end of the Strait. The predominance of diurnal tides along the southwest to the south coast of Taiwan is attributed to the quasi-resonance of diurnal waves in the South China Sea. The tidal range is small and tidal currents are weak off the east coast of Taiwan. Barotropic tidal energy is mostly dissipated on the shallow banks of the southwestern Strait. Results summarized from sensitivity tests on the bottom drag coefficient (CD and horizontal eddy viscosity (AM indicate that CD = 0.0015 - 0.00175 and AM = 150 m2 s-1 lead to the best model-data fit when compared to the observed tidal sea levels at ten reference tide-gauge stations around Taiwan. The averaged root-mean-squared (RMS differences of the simulated tidal sea level for the six principal constituents of O1, P1, K1, N2, M2, and S2 are significantly reduced to 1.3, 0.7, 2.0, 1.6, 5.1, and 3.1 cm, respectively, compared to that calculated from a _ resolution global tide harmonic constant database, NAO.99b (Matsumoto et al. 2000. The averaged RMS differences of barotropic tidal currents (U, V for O1, K1, M2, and S2 are (0.92, 1.64, (1.17, 0.61, (3.88, 2.37, and (1.52, 1.20 cm s-1. A database of tidal sea levels and current harmonic constants, TWTIDE08, for Q1, O1, P1, K1, J1, OO1, 2N2, _ N2, _ M2, L2, T2, S2, and K2 is established with this study.

  8. NONLINEAR TIDES IN CLOSE BINARY SYSTEMS

    International Nuclear Information System (INIS)

    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 ∼3[P/10 days] for a solar-type star) and drives them as a single coherent unit with growth rates that are a factor of ≈N faster than the standard three-wave parametric instability. These are local instabilities viewed through the lens of global analysis; the coherent global growth rate follows local rates in the regions where the shear is strongest. In solar-type stars, the dynamical tide is unstable to this collective version of the parametric instability for even sub-Jupiter companion masses with P ∼< a month. (4) Independent of the parametric instability, the dynamical and equilibrium tides excite a wide range of stellar p-modes and g-modes by nonlinear inhomogeneous forcing

  9. Nonlinear interactions between gravity waves and tides

    Institute of Scientific and Technical Information of China (English)

    LIU Xiao; XU JiYao; MA RuiPing

    2007-01-01

    In this study, we present the nonlinear interactions between gravity waves (GWs) and tides by using the 2D numerical model for the nonlinear propagation of GWs in the compressible atmosphere. During the propagation in the tidal background, GWs become instable in three regions, that is z = 75-85 km, z =90-110 km and z= 115-130 km. The vertical wavelength firstly varies gradually from the initial 12 km to 27 km. Then the newly generated longer waves are gradually compressed. The longer and shorter waves occur in the regions where GWs propagate in the reverse and the same direction of the horizontal mean wind respectively. In addition, GWs can propagate above the main breaking region (90-110 km). During GWs propagation, not only the mean wind is accelerated, but also the amplitude of tide is amplified. Especially, after GWs become instable, this amplified effect to the tidal amplitude is much obvious.

  10. Nonlinear interactions between gravity waves and tides

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this study, we present the nonlinear interactions between gravity waves (GWs) and tides by using the 2D numerical model for the nonlinear propagation of GWs in the compressible atmosphere. During the propagation in the tidal background, GWs become instable in three regions, that is z = 75―85 km, z = 90―110 km and z = 115―130 km. The vertical wavelength firstly varies gradually from the initial 12 km to 27 km. Then the newly generated longer waves are gradually compressed. The longer and shorter waves occur in the regions where GWs propagate in the reverse and the same direction of the hori-zontal mean wind respectively. In addition, GWs can propagate above the main breaking region (90—110 km). During GWs propagation, not only the mean wind is accelerated, but also the amplitude of tide is amplified. Especially, after GWs become instable, this amplified effect to the tidal amplitude is much obvious.

  11. Thermal Tides in Fluid Extrasolar Planets

    OpenAIRE

    Arras, Phil; Socrates, Aristotle

    2009-01-01

    Asynchronous rotation and orbital eccentricity lead to time-dependent irradiation of the close-in gas giant exoplanets -- the hot Jupiters. This time-dependent surface heating gives rise to fluid motions which propagate throughout the planet. We investigate the ability of this "thermal tide" to produce a quadrupole moment which can couple to the stellar gravitational tidal force. While previous investigations discussed planets with solid surfaces, here we focus on entirely fluid planets in or...

  12. Thermal Tides in Short Period Exoplanets

    OpenAIRE

    Arras, Phil; Socrates, Aristotle

    2009-01-01

    Time-dependent insolation in a planetary atmosphere induces a mass quadrupole upon which the stellar tidal acceleration can exert a force. This "thermal tide" force can give rise to secular torques on the planet and orbit as well as radial forces causing eccentricity evolution. We apply this idea to the close-in gas giant exoplanets ("hot Jupiters"). The response of radiative atmospheres is computed in a hydrostatic model which treats the insolation as a time-dependent heat source, and solves...

  13. Super inertial tides over irregular narrow shelves

    OpenAIRE

    Quaresma Dos Santos, Luis

    2012-01-01

    Oceanic internal tides are ubiquitous dynamic features, densely observed near continental margins. Their sea-surface signature is frequently printed in remote sensing images, showing complex wave patterns over irregular shelves such as the West-Iberian margin. Their origin and spatial distribution is the subject of the present work, which explores the physics behind the generation and propagation of these baroclinic modes, over submarine canyon and promontory shelf features. It focuses on the...

  14. Star-planet interactions: II. Is planet engulfment the origin of fast rotating red giants?

    OpenAIRE

    Privitera, Giovanni; Meynet, Georges; Eggenberger, Patrick; Vidotto, Aline A.; Villaver, Eva; Bianda, Michele

    2016-01-01

    Context. Fast rotating red giants in the upper part of the red giant branch have surface velocities that cannot be explained by single star evolution. Aims. We check whether tides between a star and a planet followed by planet engulfment can indeed accelerate the surface rotation of red giants for a sufficient long time in order to produce these fast rotating red giants. Methods. Using rotating stellar models, accounting for the redistribution of the angular momentum inside the star by differ...

  15. Tides and the Evolution of Planetary Habitability

    Science.gov (United States)

    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.

  16. Tides and the Evolution of Planetary Habitability

    CERN Document Server

    Barnes, Rory; Jackson, Brian; Greenberg, Richard

    2008-01-01

    Tides raised on a planet by its host star's gravity can reduce a planet's orbital semi-major axis and eccentricity. This effect is only relevant for planets orbiting very close to their host stars. The habitable zones of low-mass stars are also close-in and tides can alter the orbits of planets in these locations. We calculate the tidal evolution of hypothetical terrestrial planets around low-mass stars and show that tides can evolve planets past the inner edge of the habitable zone, sometimes in less than 1 billion years. This migration requires large eccentricities (>0.5) and low-mass stars (<0.35 M_Sun). Such migration may have important implications for the evolution of the atmosphere, internal heating and the Gaia hypothesis. Similarly, a planet detected interior to the habitable zone could have been habitable in the past. We consider the past habitability of the recently-discovered, ~5 M_Earth planet, Gliese 581 c. We find that it could have been habitable for reasonable choices of orbital and physic...

  17. Earthquake, strong tide and global low temperature

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    "La Madre" is a kind of upper atmospheric air current, and occurs as "warm phase" and "cold phase" in the sky of Pacific Ocean alternately. There exists this phenomenon, called "Oscillation Decade in the Pacific" (ODP), for 20~30years. It is concerned with 60 year cycle of the tides. Lunar oscillations explain an intriguing 60-year cycle in the world's temperature. Strong tides increase the vertical mixing of water in the oceans, drawing cold ocean water from the depths to surface, where it cools the atmosphere above. The first strong seismic episode in China was from 1897 to 1912; the second to the fifth was the in1920-1937, 1946-1957, 1966-1980, 1991-2002, tsrectruely. The alternative boundaries of"La Madre" warm phase and cold phase were in 1890, 1924, 1946 and 2000, which were near the boundaries of four strong earthquakes. It indicated the strong earthquakes closedly related with the substances' motion of atmosphere, hydrosphere and lithosphere, the change of gravity potential, and the exchange of angular momentum. The strong earthquakes in the ocean bottom can bring the cool waters at the deep ocean up to the ocean surface and make the global climate cold. the earthquake, strong tide and global low temperature are close inrelntion for each othen.

  18. Aerosol studies

    International Nuclear Information System (INIS)

    As part of the continuing studies of the effects of very severe reactor accidents, an effort was made to develop, test, and improve simple, effective, and inexpensive methods by which the average citizen, using only materials readily available, could protect his residence, himself, and his family from injury by toxic aerosols. The methods for protection against radioactive aerosols should be equally effective against a clandestine biological attack by terrorists. The results of the tests to date are limited to showing that spores of the harmless bacterium, bacillus globegii (BG), can be used as a simulant for the radioactive aerosols. An aerosol generator of Lauterbach type was developed which will produce an essentially monodisperse aerosol at the rate of 109 spores/min. Analytical techniques have been established which give reproducible results. Preliminary field tests have been conducted to check out the components of the system. Preliminary tests of protective devices, such as ordinary vacuum sweepers, have given protection factors of over 1000

  19. Stratospheric aerosols

    International Nuclear Information System (INIS)

    Stratospheric aerosol measurements can provide both spatial and temporal data of sufficient resolution to be of use in climate models. Relatively recent results from a wide range of instrument techniques for measuring stratospheric aerosol parameters are described. Such techniques include impactor sampling, lidar system sensing, filter sampling, photoelectric particle counting, satellite extinction-sensing using the sun as a source, and optical depth probing, at sites mainly removed from tropospheric aerosol sources. Some of these techniques have also had correlative and intercomparison studies. The main methods for determining the vertical profiles of stratospheric aerosols are outlined: lidar extinction measurements from satellites; impactor measurements from balloons and aircraft; and photoelectric particle counter measurements from balloons, aircraft, and rockets. The conversion of the lidar backscatter to stratospheric aerosol mass loading is referred to. Absolute measurements of total solar extinction from satellite orbits can be used to extract the aerosol extinction, and several examples of vertical profiles of extinction obtained with the SAGE satellite are given. Stratospheric mass loading can be inferred from extinction using approximate linear relationships but under restrictive conditions. Impactor sampling is essentially the only method in which the physical nature of the stratospheric aerosol is observed visually. Vertical profiles of stratospheric aerosol number concentration using impactor data are presented. Typical profiles using a dual-size-range photoelectric dustsonde particle counter are given for volcanically disturbed and inactive periods. Some measurements of the global distribution of stratospheric aerosols are also presented. Volatility measurements are described, indicating that stratospheric aerosols are composed primarily of about 75% sulfuric acid and 25% water

  20. NONLINEAR TIDES IN CLOSE BINARY SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-06-01

    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

  1. The Role of Gravity Waves in Modulating Atmospheric Tides

    Science.gov (United States)

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

    1999-01-01

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

  2. Eye redness

    Science.gov (United States)

    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. ...

  3. High tide, news from a warming world

    International Nuclear Information System (INIS)

    While governments debate and scientists test ever-more complicated hypotheses, ordinary people all over the world are starting to notice the effects of global warming. In High Tide, British journalist Mark Lynas visits global hot spots to record people's reactions and sound a clarion call for action. Readers looking for a 'we are the world' approach to climate change may be taken aback by Lynas' flat expression of the uncomfortable truth: 'Every time America votes, the world holds its breath.... Climate change begins and ends in America'. Lynas damns the George W. Bush administration for undermining global efforts such as the Kyoto Protocol as well as actively preventing innovation within the United States that would reduce auto and industrial emissions. But High Tide is not the firs or the best book to do that; instead, its narrative strength is in the riveting stories of how small towns, islands, riverside cities, and rural areas are being slowly destroyed. Gardeners in England will be unable to grow heritage plant species within the next 75 years. The Alaskan permafrost is melting, as temperatures there increase ''ten times faster than in the rest of the world.'' An entire Pacific Island nation--Tuvalu--will soon disappear beneath the rising sea, leaving its people homeless. Lynas visits Alaska, Tuvalu, Peru, China, and the east coast of the United States, documenting the lives, places, and cultures that will be lost in the decades to come. Thankfully, just when hopelessness threatens to overwhelm the reader, High Tide offers a five-step plan to mitigate the most catastrophic effects of global climate change. Every step in the plan involves action by United States citizens and their elected representatives, offering American activists and visionaries a chance to do penance for wrecking parts of the world far from our own driveways

  4. THERMAL TIDES IN FLUID EXTRASOLAR PLANETS

    International Nuclear Information System (INIS)

    Asynchronous rotation and orbital eccentricity lead to time-dependent irradiation of the close-in gas giant exoplanets-the hot Jupiters. This time-dependent surface heating gives rise to fluid motions which propagate throughout the planet. We investigate the ability of this 'thermal tide' to produce a quadrupole moment which can couple to the stellar gravitational tidal force. While previous investigations discussed planets with solid surfaces, here we focus on entirely fluid planets in order to understand gas giants with small cores. The Coriolis force, thermal diffusion, and self-gravity of the perturbations are ignored for simplicity. First, we examine the response to thermal forcing through analytic solutions of the fluid equations which treat the forcing frequency as a small parameter. In the 'equilibrium tide' limit of zero frequency, fluid motion is present but does not induce a quadrupole moment. In the next approximation, finite frequency corrections to the equilibrium tide do lead to a nonzero quadrupole moment, the sign of which torques the planet away from synchronous spin. We then numerically solve the boundary value problem for the thermally forced, linear response of a planet with neutrally stratified interior and a stably stratified envelope. The numerical results find quadrupole moments in agreement with the analytic non-resonant result at a sufficiently long forcing period. Surprisingly, in the range of forcing periods of 1-30 days, the induced quadrupole moments can be far larger than the analytic result due to response of internal gravity waves which propagate in the radiative envelope. We discuss the relevance of our results for the spin, eccentricity, and thermal evolution of hot Jupiters.

  5. Tides and sea-level variability

    Digital Repository Service at National Institute of Oceanography (India)

    Shetye, S.R.; Suresh, I.; Sundar, D.

    on the Earth?s surface consist of a superposition of oscillations with well-known periods. The periods depend on characteristics of the motion of the Sun?Earth?Moon system. The study of tides since the last few hundred years has carefully documented the most...; Canadian Journal of Public Health 75 49?56. ETOPO2(2007)Onlinedocumentation.http://www. ngdc. noaa. gov/mgg/fliers/ 06mgg01. html. Friedrichs C. T. and Aubrey D. G. (1994) Tidal propagation in strongly convergent channels; Journal of Geophysical Research 99...

  6. Tropospheric Aerosols

    Science.gov (United States)

    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

  7. Influence analysis of Arctic tide gauges using leverages

    DEFF Research Database (Denmark)

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

    2014-01-01

    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...

  8. Influence analysis of Arctic tide gauges using leverages

    DEFF Research Database (Denmark)

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

    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...

  9. Subtidal water level variation controlled by river flow and tides

    NARCIS (Netherlands)

    Buschman, F.A.; Hoitink, A.J.F.; Vegt, van der M.; Hoekstra, P.

    2009-01-01

    Subtidal water level dynamics in the Berau river, East Kalimantan, Indonesia, feature a pronounced fortnightly variation. The daily mean water levels at a station about 60 km from the sea are 0.2–0.6 m higher during spring tide than during neap tide. To explain the underlying mechanisms, a local sub

  10. Characteristics of Tides in the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Sindhu, B.; Unnikrishnan, A.S.

    and the amplitudes of semi-diurnal tides are doubled in these regions while the diurnal tides amplify only marginally, which is consistent with Clarke and Battisti theory. In the north eastern end of the head bay and the Gulf of Martaban, the geometrical...

  11. AN EXTENDED MODELING OF TIDE-WAVE MOTION

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    By vertical boundary conditions, a spectral expansion of horizontal tide-wave velocity is done in vertical direction in terms of a complete basis functions selected properly, hence a relation between tide-levels and spectral components is found theoretically under condition of ignoring the horizontal friction stress and nonlinear effect. And a relation between bottom friction of tide-current, which satisfies the viscous condition on sea-bottom, and tide-levels is determined. The relation is different from the relation of the traditional parameterizing of bottom friction. Moreover integration of the continuity equation and momentum equations is carried out in the vertical direction using zero flux condition on solid boundaries and inputting condition on open boundaries, and then a boundary-value problem of elliptic form on the tide-levels is constructed.

  12. Arctic Tides from GPS on sea-ice

    DEFF Research Database (Denmark)

    Kildegaard Rose, Stine; Skourup, Henriette; Forsberg, René

    2013-01-01

    The presence of sea-ice in the Arctic Ocean plays a significant role in the Arctic climate. Sea-ice dampens the ocean tide amplitude with the result that global tidal models perform less accurately in the polar regions. This paper presents, a kinematic processing of global positioning system (GPS......) placed on sea-ice, at six different sites north of Greenland for the preliminary study of sea surface height (SSH), and tidal analysis to improve tide models in the Central Arctic. The GPS measurements are compared with the Arctic tide model AOTIM-5, which assimilates tide-gauges and altimetry data. The...... results show coherence between the GPS buoy measurements, and the tide model. Furthermore, we have proved that the reference ellipsoid of WGS84, can be interpolated to the tidal defined zero level by applying geophysical corrections to the GPS data....

  13. Estimating Tides from a Planetary Flyby Mission

    Science.gov (United States)

    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

  14. Lake-level variations and tides in Lago Argentino, Patagonia: insights from pressure tide gauge records

    Directory of Open Access Journals (Sweden)

    Andreas Richter

    2015-08-01

    Full Text Available Based on precise pressure tide gauge observations lake-level records are derived for two sites in Lago Argentino, southern Patagonia, of 2.5 and 1 years of duration. Applying the tools of time series analysis, the principal processes affecting the lake level are identified and quantified. Lake-level changes reflecting variations in lake volume are dominated by a seasonal cycle of 1.2 m in amplitude. Lake-volume changes occur in addition with a daily period in response to melt water influx from surrounding glaciers. Sporadic lake-volume jumps are caused by bursting of the ice dam of Perito Moreno glacier. Water movements in Lago Argentino are dominated by surface seiches reaching 20 cm in amplitude. Lake tides reach a maximum amplitude of 3 mm. The comparison of the tidal signal extracted from the lake-level observations with a model composed of the contributions of body tide and ocean tidal loading indicates a phase shift of 23° which is most likely explained by an 1 hour phase lag of global ocean tide models in the region of the highly fragmented Pacific coast. The comparison of the obtained results with those of a previous study of Lago Fagnano, Tierra del Fuego, allows to relate differences in the hydrological and hydrodynamic processes between both lakes to morphological properties. This leads to a tentative prediction of the lake-level variability to be expected from other great Patagonian lakes. The presented geodetic results shall serve as a starting point for a detailed limnological investigation of these aquatic ecosystems.

  15. The anelastic equilibrium tide in exoplanetary systems

    CERN Document Server

    Remus, F; Zahn, J -P; Lainey, V

    2012-01-01

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

  16. A New Neighboring Pixels Method for Reducing Aerosol Effects on the NDVI Images

    OpenAIRE

    Dandan Wang; Yunhao Chen; Mengjie Wang; Jingling Quan; Tao Jiang

    2016-01-01

    A new algorithm was developed in this research to minimize aerosol effects on the normalized difference vegetation index (NDVI). Simulation results show that in red-NIR reflectance space, variations in red and NIR channels to aerosol optical depth (AOD) follow a specific pattern. Based on this rational, the apparent reflectance in these two bands of neighboring pixels were used to reduce aerosol effects on NDVI values of the central pixel. We call this method the neighboring pixels (NP) algor...

  17. Indoor aerosols

    DEFF Research Database (Denmark)

    Morawska, L.; Afshari, Alireza; N. Bae, G.;

    2013-01-01

    understanding of the risks posed by personal exposure to indoor aerosols. Limited studies assessing integrated daily residential exposure to just one particle size fraction, ultrafine particles, show that the contribution of indoor sources ranged from 19% to 76%. This indicates a strong dependence on resident...

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  20. Prediction of tides using back-propagation neural networks

    Digital Repository Service at National Institute of Oceanography (India)

    Mandal, S.

    Prediction of tides is very much essential for human activities and to reduce the construction cost in marine environment. This paper presents an application of the artificial neural network with back-propagation procedures for accurate prediction...

  1. Propagation of tides in the Mandovi-Zuari estuarine network

    Digital Repository Service at National Institute of Oceanography (India)

    Shetye, S.R.; Gouveia, A.D.; Singbal, S.Y.S.; Naik, C.G.; Sundar, D.; Michael, G.S.; Nampoothiri, G.

    The propagation of tides in the Mandovi-Zuari estuarine network was studied based on the hydrographic observations; mathematical modelling; and chemistry of estuaries. The data was collected during the dry and wet season. The tidal circulation...

  2. Influence analysis of Arctic tide gauges using leverages

    OpenAIRE

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

    2014-01-01

    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 ...

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

    Science.gov (United States)

    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].

  4. Wavelet approach to the determination of gravity tide parameters

    Institute of Scientific and Technical Information of China (English)

    柳林涛; 许摩泽; 孙和平; 郝兴华

    2000-01-01

    A new approach is proposed for the determination of gravity tide parameters. Three pairs of compactly supported wavelet filters are introduced in the approach. They can efficiently extract the objective tides from the gravity observation series. The new approach guarantees a direct and precise analysis on the tidal gravity records of any sampling length. The new approach is applied to the harmonic analysis on Wuhan superconducting gravimeter records. The results clearly show the resonant effects of the Earth Nearly Diurnal Free Wobble (NDFW).

  5. REGIONAL OCEAN TIDE LOADING MODELING AROUND THE IBERIAN PENINSULA

    OpenAIRE

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

    2009-01-01

    Abstract We developed a new 1/12-degree 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 modeling 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 dept...

  6. Aerosol filtration

    International Nuclear Information System (INIS)

    This report summarizes the work on the development of fibre metallic prefilters to be placed upstream of HEPA filters for the exhaust gases of nuclear process plants. Investigations at ambient and high temperature were carried out. Measurements of the filtration performance of Bekipor porous webs and sintered mats were performed in the AFLT (aerosol filtration at low temperature) unit with a throughput of 15 m3/h. A parametric study on the influence of particle size, fibre diameter, number of layers and superficial velocity led to the optimum choice of the working parameters. Three selected filter types were then tested with polydisperse aerosols using a candle-type filter configuration or a flat-type filter configuration. The small-diameter candle type is not well suited for a spraying nozzles regeneration system so that only the flat-type filter was retained for high-temperature tests. A high-temperature test unit (AFHT) with a throughput of 8 to 10 m3/h at 4000C was used to test the three filter types with an aerosol generated by high-temperature calcination of a simulated nitric acid waste solution traced with 134Cs. The regeneration of the filter by spray washing and the effect of the regeneration on the filter performance was studied for the three filter types. The porous mats have a higher dust loading capacity than the sintered web which means that their regeneration frequency can be kept lower

  7. TOMS Absorbing Aerosol Index

    Data.gov (United States)

    Washington University St Louis — TOMS_AI_G is an aerosol related dataset derived from the Total Ozone Monitoring Satellite (TOMS) Sensor. The TOMS aerosol index arises from absorbing aerosols such...

  8. Differences between mean tide level and mean sea level

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    KAUST Repository

    Guo, Daquan

    2015-04-01

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

  12. Aerosol Observation System

    Data.gov (United States)

    Oak Ridge National Laboratory — The aerosol observation system (AOS) is the primary Atmospheric Radiation Measurement (ARM) platform for in situ aerosol measurements at the surface. The principal...

  13. Red Sirius

    International Nuclear Information System (INIS)

    A hypothesis is proposed explaining the assumption that Sirius changes its colour from red in the second century to pale blue in the tenth century A.D. The hypothesis is based on the possibility of transformation of a Sirius satellite (Sirius B) from a red giant in the past to a white dwarf in the present. Such a transformation would have been accompanied by an explosion of Sirius B, which is clearly visible from the Earth. The fact that the increase in Sirius brightness by 4-5 units is not reflected in historical chronicles is attributed to the degradation of sciences in Europe in 4-10 centuries

  14. Revisiting the pole tide for and from satellite altimetry

    Science.gov (United States)

    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.

  15. Seasonal Variations in Pluto's Atmospheric Tides

    Science.gov (United States)

    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

  16. Wave-tide-surge coupled model simulation for Typhoon Maemi

    Institute of Scientific and Technical Information of China (English)

    CHOI Byung Ho; KIM Dong Chule; KIM Young Bok; KIM Hyun Seung

    2007-01-01

    Reasonably accurate predictions of wave heights, current and elevations during storm events are vital information for marine operations and design of offshore and coastal structures in the surrounding seas of Korea Peninsula. Ocean circulation and wind-wave models have traditionally been run separately, but recent researches have identified potentially important interactions between current and wave motions. The coupled tide-surge and the WAM wave models at the atmospheric boundary layer and bottom boundary layer around the Korea Peninsula are applied for the Typhoon Maemi (0314) event. Communication between the models is achieved using MPI. Results are compared with coastal tide gauges and moored wave buoys and comparisons are also made between wave computations from the coupled model and the independent third generation wave models. Results suggest that applying the tide-surge-coupled model can be an effective means of obtaining wave and storm surge predictions simultaneously.

  17. TideWatch: Fingerprinting the cyclicality of big data workloads

    KAUST Repository

    Williams, Daniel W.

    2014-04-01

    Intrinsic to \\'big data\\' processing workloads (e.g., iterative MapReduce, Pregel, etc.) are cyclical resource utilization patterns that are highly synchronized across different resource types as well as the workers in a cluster. In Infrastructure as a Service settings, cloud providers do not exploit this characteristic to better manage VMs because they view VMs as \\'black boxes.\\' We present TideWatch, a system that automatically identifies cyclicality and similarity in running VMs. TideWatch predicts period lengths of most VMs in Hadoop workloads within 9% of actual iteration boundaries and successfully classifies up to 95% of running VMs as participating in the appropriate Hadoop cluster. Furthermore, we show how TideWatch can be used to improve the timing of VM migrations, reducing both migration time and network impact by over 50% when compared to a random approach. © 2014 IEEE.

  18. Reprocessed height time series of GPS stations at tide gauges

    Directory of Open Access Journals (Sweden)

    S. Rudenko

    2012-07-01

    Full Text Available Precise weekly positions of 403 Global Positioning System (GPS stations located worldwide are obtained by reprocessing GPS data of these stations at the time span from 4 January 1998 until 29 December 2007. The used processing algorithm and models as well as the solution and results obtained are presented. Vertical velocities of GPS stations having tracking history longer than 2.5 yr are computed and compared with the estimates from the colocated tide gauges and other GPS solutions. Examples of typical behavior of station height changes are given and interpreted. The derived time series and vertical motions of continuous GPS at tide gauges stations can be used for correcting tide gauge estimates of regional and global sea level changes.

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

    Science.gov (United States)

    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.

  20. Tide-surge interaction in the English Channel

    Directory of Open Access Journals (Sweden)

    D. Idier

    2012-12-01

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

  1. Remote Sensing Monitoring of Tide Propagation Through Coastal Wetlands

    Science.gov (United States)

    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. Wavelet approach to the determination of gravity tide parameters

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new approach is proposed for the determination of gravity tide parameters.Three pairs of compactly supported wavelet filters are introduced in the approach.They can efficiently extract the objective tides from the gravity observation series.The new approach guarantees a direct and precise analysis on the tidal gravity records of any sampling length.The new approach is applied to the harmonic analysis on Wuhan superconducting gravimeter records.The results clearly show the resonant effects of the Earth Nearly Diurnal Free Wobble (NDFW).

  3. Tide Corrections for Coastal Altimetry: Status and Prospects

    Science.gov (United States)

    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

  4. Accuracy assessment of global barotropic ocean tide models

    DEFF Research Database (Denmark)

    Stammer, D.; Ray, R. D.; Andersen, Ole Baltazar;

    2014-01-01

    -water regions and also in the deep ocean. The root-sum-square differences between tide observations and the best models for eight major constituents are approximately 0.9, 5.0, and 6.5 cm for pelagic, shelf, and coastal conditions, respectively. Large intermodel discrepancies occur in high latitudes, but...... testing in those regions is impeded by the paucity of high-quality in situ tide records. Long-wavelength components of models tested by analyzing satellite laser ranging measurements suggest that several models are comparably accurate for use in precise orbit determination, but analyses of GRACE...

  5. The impact of ocean tides on a climate model simulation.

    OpenAIRE

    Müller, M; Haak, H.; J. Jungclaus; Maik Thomas;  ,

    2008-01-01

    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 A...

  6. NOS CO-OPS Water Level Data, Tide Prediction, 60-Minute

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset has High Low Tide Predictions from NOAA NOS Center for Operational Oceanographic Products and Services (CO-OPS). The official Tide and Tidal Current...

  7. NOS CO-OPS Water Level Data, Tide Prediction, 6-Minute

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset has High Low Tide Predictions from NOAA NOS Center for Operational Oceanographic Products and Services (CO-OPS). The official Tide and Tidal Current...

  8. NOS CO-OPS Water Level Data, High Low Tide Prediction

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset has High Low Tide Predictions from NOAA NOS Center for Operational Oceanographic Products and Services (CO-OPS). The official Tide and Tidal Current...

  9. Aerosol typing - key information from aerosol studies

    Science.gov (United States)

    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

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

    OpenAIRE

    Kusmierczyk-Michulec, J.T.; Eijk, A.M.J. van

    2006-01-01

    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 aero...

  11. Influence analysis of Arctic tide gauges using leverages

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  13. Correcting GRACE gravity fields for ocean tide effects

    DEFF Research Database (Denmark)

    Knudsen, Per; Andersen, Ole Baltazar

    2002-01-01

    tide model if altimetry corrected for inverted barometer effects was used in its derivation. To study the temporal characteristics of the ocean tidal constituents when sampled by GRACE, approximate alias frequencies were derived assuming a sampling of half a sidereal day. Those results show that the...

  14. 1620 Geographos and 433 Eros: Shaped by Planetary Tides

    Science.gov (United States)

    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.

  15. Propagation of tides in the Mandovi and Zuari estuaries

    Digital Repository Service at National Institute of Oceanography (India)

    Shetye, S.R.

    of riverine freshwater during the southwest monsoon and little during the rest of the year. Tides in the channels exhibit the following characteristics: (a) The speed of propagation is about 6.5 ms sup(-1); (b) tidal amplitude remains unchanged over a distance...

  16. The BlueTides Simulation: First Galaxies and Reionization

    CERN Document Server

    Feng, Yu; Croft, Rupert A; Bird, Simeon; Battaglia, Nicholas; Wilkins, Stephen

    2015-01-01

    We introduce the BlueTides simulation and report initial results for the luminosity functions of the first galaxies and AGN, and their contribution to reionization. BlueTides was run on the BlueWaters cluster at NCSA from $z=99$ to $z=8.0$ and includes 2$\\times$7040$^3$ particles in a $400$Mpc/h 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. The star formation rate density in the simulation is a good match to current observational data at $z\\sim 8-10$. We find good agreement between observations and the predicted galaxy luminosity function in the currently observable range $-18\\le M_{\\mathrm UV} \\le -22.5$ with some dust extinction required to match the abundance of brighter objects. BlueTides implements a patchy reionization model that produces a fluct...

  17. Sea level reconstruction from satellite altimetry and tide gauge data

    DEFF Research Database (Denmark)

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

    2012-01-01

    Ocean satellite altimetry has provided global sets of sea level data for the last two decades, allowing determination of spatial patterns in global sea level. For reconstructions going back further than this period, tide gauge data can be used as a proxy. We examine different methods of combining...

  18. Aerosol mobility size spectrometer

    Science.gov (United States)

    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.

  19. Quality assessment of altimeter data through tide gauge comparisons

    Science.gov (United States)

    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.

  20. Environmental Chemistry and Chemical Ecology of "Green Tide" Seaweed Blooms.

    Science.gov (United States)

    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

  1. Red Alive

    Directory of Open Access Journals (Sweden)

    Reynaldo Thompson Lopez

    2010-01-01

    Full Text Available Red Alive is an installation consisting of video, sound and an aquarium containing a beta fish in it. The idea came out by observing the peculiar behavior of the small creature that fights to death with other fishes of his kind that are in his proximity. Its character and physical appearance are good reasons to capture it in a video recording since its color and sensual movements contrast with its aggressive instinct. The conduct of such fish is similar in many aspects to those of humans.

  2. Red Alive

    OpenAIRE

    Reynaldo Thompson Lopez

    2010-01-01

    Red Alive is an installation consisting of video, sound and an aquarium containing a beta fish in it. The idea came out by observing the peculiar behavior of the small creature that fights to death with other fishes of his kind that are in his proximity. Its character and physical appearance are good reasons to capture it in a video recording since its color and sensual movements contrast with its aggressive instinct. The conduct of such fish is similar in many aspects to those of humans.

  3. Occurrence of red tide caused by Karenia mikimotoi (toxic dinoflagellate) in the Southwest coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Madhu, N.V.; Reny, P.D.; Paul, M.; Ullas, N.; Resmi, P.

    .5-39.9 mu M) and chlorophyll a (av. 56.8 + or -23.7 mg m sup(-3)) concentration were observed during the bloom period. Microscopic analysis revealed that the discoloration was caused by an unarmored toxic dinoflagellate, Karenia mikimotoi Miyake & Kominami...

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

    OpenAIRE

    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 im...

  5. Nutrient environment of red tide- infested waters off south-west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Joseph, T.; Shaiju, P.; Laluraj, C.M.; Balachandran, K.K.; Nair, M.; George, R.; Nair, K.K.C.; Sahayak, S.; Prabhakaran, M.P.

    /Accepted: 28 August 2007 /Published online: 19 September 2007 # Springer Science + Business Media B.V. 2007 Abstract The bloom-infested waters along the south- west coast of India were assessed to bring about... duringthisperiodwasnoticeable (Ramaiah et al. 2005) According to UNEP, ‘toxic algae bloom is an indicator of an upset in the environmental conditions. Toxic blooms indicate the declining health of the water body, which is why the phenomenon should be viewed seriously. Inflowing...

  6. SAHARAN DUST AND FLORIDA RED TIDES: THE CYANOPHYTE CONNECTION. (R827085)

    Science.gov (United States)

    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. Application of an Ocean Color Algal Taxa Detection Model to Red Tides in the Southern Benguela

    OpenAIRE

    Etheridge, S.M.; Roesler, C.S.; Pitcher, G. C.

    2000-01-01

    A forward reflectance model is used to demonstrate the sensitivity of hyperspectral ocean color observations to phytoplankton biomass, species composition and cell size. An inverse ocean color model is developed which has explicit terms for 5 taxonomic groups of phytoplankton. The model expresses the contributions of each group in terms of the magnitude of the absorption coefficient, which is proportional to biomass. The model is applied to a time series of reflectance data from a...

  8. Prediction of the Development of Red Tide by the Spectral Analysis : A New Approach.

    OpenAIRE

    Yamamoto, Tamiji

    1992-01-01

    渥美湾において珪藻 Eucampia zodiacus のブルームの始まりから終わりにかけて連続した観測を行った。表層から連続的に得られた水温、塩分および蛍光度のデータセットに対してスペクトル解析を行った。それぞれのパラメータのスペクトル密度のピークの不一致から、植物プランクトンのパッチは水塊の分布に対してかなり独立に振舞っていることがわかった。赤潮はしばしば湾全体に広がる。したがって、渥美湾のように小規模な湾においては、植物プランクトンの増殖と渦の物理的消散がバランスする、いわゆる植物プランクトンパッチの「臨界サイズ」の観点からは赤潮の発達過程を議論することは困難である。しかしながら、植物プランクトンパッチサイズの成長と衰退は蛍光度のパワースペクトルの密度のピークのズレで追うことができた。パラメータ間のコヒーレンスは気象の変化とそれに続くブルームの変遷を直接反映していた。スペクトル解析は富栄養化した湾における赤潮の発達を明確に予測するためのルーチン作業として採用できよう。...

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

    OpenAIRE

    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.; F. E. Muller-Karger; Shinn, E.; Steidinger, K. A.

    2006-01-01

    [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 p...

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

    Science.gov (United States)

    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)

  11. A Semianalytical Model Using MODIS Data to Estimate Cell Density of Red Tide Algae (Aureococcus anophagefferens)

    OpenAIRE

    Lingling Jiang; Lin Wang; Xinyu Zhang; Yanlong Chen; Deqi Xiong

    2016-01-01

    A multiband and a single-band semianalytical model were developed to predict algae cell density distribution. The models were based on cell density (N) dependent parameterizations of the spectral backscattering coefficients, bb(λ), obtained from in situ measurements. There was a strong relationship between bb(λ) and N, with a minimum regression coefficient of 0.97 at 488 nm and a maximum value of 0.98 at other bands. The cell density calculated by the multiband inversion model was similar to ...

  12. Wetland InSAR as a Tool for Monitoring Ocean Tide Propagation through Coastal Wetlands

    Science.gov (United States)

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

    2012-12-01

    Coastal wetlands 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. Wetland InSAR observations provide a new 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, InSAR observations are evaluated for their sensitivity to detect surface water level changes in response to ocean tide propagation through the coastal Everglades' mangrove forests. We used three datasets, which were acquired by the following SAR satellites: ALOS (L-band, 46 day repeat path), Radarsat-2 (C-band, 24 day repeat path), and TerraSAR (X-band, 11 day repeat path). The ALOS interferograms possessed fringes following the transition between the fresh- and salt-water vegetation. Whereas the Radarsat-2 and TerraSAR-X interferograms revealed well-defined, continuous fringe patterns surrounding prominent tidal channels oriented normal to the coastline. Our results suggest that the different fringe patterns obtained by three sensors most likely reflect spatial resolution differences between the three data types. The high spatial resolution wetland InSAR, particularly TerraSAR-X, observations provide important constraints for detailed coastal wetland flow models. Such models can lead to improved quantitative tools for better forecasting tidal flow propagation through coastal wetlands and better understanding of the hydro-ecology of this delicate ecosystem. Figure 1: (a) Google

  13. Facility of aerosol filtration

    International Nuclear Information System (INIS)

    Said invention relates to a facility of aerosol filtration, particularly of sodium aerosols. Said facility is of special interest for fast reactors where sodium fires involve the possibility of high concentrations of sodium aerosols which soon clog up conventional filters. The facility intended for continuous operation, includes at the pre-filtering stage, means for increasing the size of the aerosol particles and separating clustered particles (cyclone separator)

  14. Multimission empirical ocean tide modeling for shallow waters and polar seas

    DEFF Research Database (Denmark)

    Cheng, Yongcun; Andersen, Ole Baltazar

    2011-01-01

    . Extensive evaluations with six tide gauge sets show that the new tide model fits the tide gauge measurements favorably to other state of the art global ocean tide models in both the deep and shallow waters, especially in the Arctic Ocean and the Southern Ocean. One example is a comparison with 207 tide...... be able to recover twice the spatial variations of the tidal signal which is particularly important in shallow waters where the spatial scale of the tidal signal is scaled down. Outside the +/- 66 degrees parallel combined Envisat, GEOSAT Follow-On, and ERS-2, data sets have been included to solve...

  15. Aerosol satellite remote sensing

    NARCIS (Netherlands)

    Veefkind, Joris Pepijn

    2001-01-01

    Aerosols are inportant for many processes in the atmosphere. Aerosols are a leading uncertainty in predicting global climate change, To a large extent this uncertainty is caused by a lack of knowledge on the occurrence and concentration of aerosols. On global scale, this information can only be o

  16. Seeing Red

    Science.gov (United States)

    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 volcanos

  17. The Effect of Tide on the Global Climate Change

    Institute of Scientific and Technical Information of China (English)

    YANG Xuexiang; CHEN Zhen; CHEN Dianyou; Qiao Qiyuan

    2002-01-01

    The differential rotation between the solid and fluid spheres caused by tidal force could explain the 1500 to 1800-year cycle of the world's temperature. Strong tide increases the vertical and horizontal mixing of water in the oceans, drawing the cold Pacific water from the depths to the surface and the warm water from the west to the east, where it cools or warms the atmosphere above, absorbs or releases CO2 to decrease or increase greenhouse effect and to make La Nina or El Nino occur in the global. The moon's declination and obliquity of the ecliptic affect the tidal intensity. The exchange of tidal energy and tide-generating force caused by the sun, moon and major planets makes the earth's layers rotate in different speeds. The differenti-al rotation between solid and fluid of the earth is the basic reason for El Nino and global climate change.

  18. Interaction of tide and salinity barrier: Limitation of numerical model

    OpenAIRE

    Suphat Vongvisessomjai; Phairot Chatanantavet2; Patchanok Srivihok

    2008-01-01

    Nowadays, the study of interaction of the tide and the salinity barrier in an estuarine area is usually accomplished vianumerical modeling, due to the speed and convenience of modern computers. However, numerical models provide littleinsight with respect to the fundamental physical mechanisms involved. In this study, it is found that all existing numericalmodels work satisfactorily when the barrier is located at some distance far from upstream and downstream boundary conditions.Results are co...

  19. Reprocessed height time series of GPS stations at tide gauges

    OpenAIRE

    S. Rudenko; Schön, N.; Uhlemann, M; G. Gendt

    2012-01-01

    Precise weekly positions of 403 Global Positioning System (GPS) stations located worldwide are obtained by reprocessing GPS data of these stations at the time span from 4 January 1998 until 29 December 2007. The used processing algorithm and models as well as the solution and results obtained are presented. Vertical velocities of GPS stations having tracking history longer than 2.5 yr are computed and compared with the estimates from the colocated tide gauges and other GPS solutions. Examples...

  20. Study of riverbank stability subjected to tide variation

    OpenAIRE

    Chhun, Soksan

    2013-01-01

    The riverbanks, subjected to seasonal flooding and tidal variation, are submitted to landslides causing property damage and sometimes human victims. The presented work is conducted to analyze the riverbank stability subjected to the tide variation by considering the influence of external and internal water flows on the bank soil. More particularly, we consider the effect of ground water variation on the soil pore pressure. The Dupuit's flow model is adopted to find the variation of the ground...

  1. Observation on Height Changes of Chinese Tide Gauges by GPS

    Institute of Scientific and Technical Information of China (English)

    LIU Genyou; ZHU Yaozhong; XU Houze; ZHANG Weimin

    2006-01-01

    The height changes of tide gauges directly influence sea level observation. For research of sea level variation in large region or globe, the land vertical displacement must be considered. Two sessions of GPS and absolute gravity observations in 2001 and 2003 are used to determine the horizontal and vertical motion of China coast in ITRF2000 and Eurasia frame. The difference between results of continuous observation and periodic observation is discussed.

  2. Towards monitoring magnetic signals generated by ocean tides

    International Nuclear Information System (INIS)

    Complete text of publication follows. The existence of magnetic signals generated by the tidal motion of ocean has been deduced from measurements of the geomagnetic observatories and CHAMP satellite mission. These signals are clearly evident in measurements taken at geomagnetic observatories close to ocean shorelines; however, the observatories are too sparsely placed to allow a global analysis of the motional induction effects in the ocean. The identification of these signals in satellite observations explicitly needs to minimize the uncertainties arising from magnetospheric and ionospheric contributions. The first clear detection of the signal related to the most strongest ocean tide (M2 tide) in magnetic satellite observations was based on the first two years of CHAMP data, only. However, since then the data have been triplicated and the understanding of contributions from multiple sources to measurements has been advanced. In this study, we seek the magnetic signals of major ocean tides in satellite observation from 2001 to 2008. Therefore, we apply a forward modelling approach to predict the magnetic signal during this period. In some recent studies the barotropic velocity fields have been deduced from altimetry data by applying the geostrophic method. Here, we predict the magnetic signal of individual tides using output from an unconstrained ocean model OMCT driven by the lunisolar tidal potential calculated form analytical ephemerides. So it is expected that the prediction of the magnetic signal is different when one or the other approach is considered, and we analyze this in more detail. Furthermore, the discrepancies between magnetic measurements and predictions may give detailed insights to the conductivity distribution within the ocean and the upper mantle.

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

    Science.gov (United States)

    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.

  4. SMLTM simulations of the diurnal tide: comparison with UARS observations

    Directory of Open Access Journals (Sweden)

    R. A. Akmaev

    Full Text Available Wind and temperature observations in the mesosphere and lower thermosphere (MLT from the Upper Atmosphere Research Satellite (UARS reveal strong seasonal variations of tides, a dominant component of the MLT dynamics. Simulations with the Spectral mesosphere/lower thermosphere model (SMLTM for equinox and solstice conditions are presented and compared with the observations. The diurnal tide is generated by forcing specified at the model lower boundary and by in situ absorption of solar radiation. The model incorporates realistic parameterizations of physical processes including various dissipation processes important for propagation of tidal waves in the MLT. A discrete multi-component gravity-wave parameterization has been modified to account for seasonal variations of the background temperature. Eddy diffusion is calculated depending on the gravity-wave energy deposition rate and stability of the background flow. It is shown that seasonal variations of the diurnal-tide amplitudes are consistent with observed variations of gravity-wave sources in the lower atmosphere.

  5. Nonlinear sea level trends from European tide gauge records

    Directory of Open Access Journals (Sweden)

    M. E. Silva

    2004-04-01

    Full Text Available Mean sea level is a variable of considerable interest in meteorological and oceanographic studies, particularly long-term sea level variation and its relation to climate changes. This study concerns the analysis of monthly mean sea level data from tide gauge stations in the Northeast Atlantic with long and continuous records. Much research effort on mean sea level studies has been focused on identifying long-term linear trends, usually estimated through least-squares fitting of a deterministic function. Here, we estimate nonparametric and robust trends using lowess, a robust smoothing procedure based on locally weighted regression. This approach is more flexible than a linear trend to describe the deterministic part of the variation in tide gauge records, which has a complex structure. A common trend pattern of reduced sea levels around 1975 is found in all the analysed records and interpreted as the result of hydrological and atmospheric forcing associated with drought conditions at the tide gauge sites. This feature is overlooked by a linear regression model. Moreover, nonlinear deterministic behaviour in the time series, such as the one identified, introduces a bias in linear trends determined from short and noisy records.Key words. Oceanography: physical (sea level variations; Hydrology (water balance

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

    Science.gov (United States)

    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.

  7. The effect of tides on dense water formation in Arctic shelf seas

    Directory of Open Access Journals (Sweden)

    C. F. Postlethwaite

    2010-09-01

    Full Text Available Ocean tides are not explicitly included in many ocean general circulation models, which will therefore omit any interactions between tides and the cryosphere. We present model simulations of the wind and buoyancy driven circulation and tides of the Barents and Kara Seas, using a 25 km × 25 km 3-D ocean circulation model coupled to a dynamic and thermodynamic sea ice model. The modeled tidal amplitudes are compared with tide gauge data and sea ice extent is compared with satellite data. Including tides in the model is found to have little impact on overall sea ice extent but is found to delay freeze up and hasten the onset of melting in tidally active coastal regions. The impact that including tides in the model has on the salt budget is investigated and found to be regionally dependent. The vertically integrated salt budget is dominated by lateral advection. This increases significantly when tides are included in the model in the Pechora Sea and around Svalbard where tides are strong. Tides increase the salt flux from sea ice by 50% in the Pechora and White Seas but have little impact elsewhere. This study suggests that the interaction between ocean tides and sea ice should not be neglected when modeling the Arctic.

  8. The effect of tides on dense water formation in Arctic shelf seas

    Directory of Open Access Journals (Sweden)

    C. F. Postlethwaite

    2011-03-01

    Full Text Available Ocean tides are not explicitly included in many ocean general circulation models, which will therefore omit any interactions between tides and the cryosphere. We present model simulations of the wind and buoyancy driven circulation and tides of the Barents and Kara Seas, using a 25 km × 25 km 3-D ocean circulation model coupled to a dynamic and thermodynamic sea ice model. The modeled tidal amplitudes are compared with tide gauge data and sea ice extent is compared with satellite data. Including tides in the model is found to have little impact on overall sea ice extent but is found to delay freeze up and hasten the onset of melting in tidally active coastal regions. The impact that including tides in the model has on the salt budget is investigated and found to be regionally dependent. The vertically integrated salt budget is dominated by lateral advection. This increases significantly when tides are included in the model in the Pechora Sea and around Svalbard where tides are strong. Tides increase the salt flux from sea ice by 50% in the Pechora and White Seas but have little impact elsewhere. This study suggests that the interaction between ocean tides and sea ice should not be neglected when modeling the Arctic.

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

    Science.gov (United States)

    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.

  10. NUMERICAL STUDY OF THE INFLUENCE OF WAVES AND TIDE-SURGE INTERACTION ON TIDE-SURGES IN THE BOHAI SEA

    Institute of Scientific and Technical Information of China (English)

    尹宝树; 侯一筠; 程明华; 苏京志; 林明祥; 李明悝; M.I.El-Sabh

    2001-01-01

    Abstract The author's combined numerical model consisting of a third generation shallow water wave model and a 3-D tide-surge model with wave-dependent surface wind stress were used to study the influence of waves on fide-surge motion. For the typical weather case, in this study, the magnitude and mechanism of the influence of waves on tide-surges in the Bohai Sea were revealed for the first time. The results showed that although consideration of the wave-dependent surface wind stresses raise slightly the traditional surface wind stress, due to the accumulated effects, the computed results are improved on the whole. Storm level maximum modulation can reach 0.4 m. The results computed by the combined model agreed well with the measured data.

  11. Aerosol Chemistry Between Two Oceans: Auckland’s Urban Aerosol

    Czech Academy of Sciences Publication Activity Database

    Coulson, G.; Olivares, G.; Salmond, J.; Talbot, Nicholas

    -: Italian Aerosol Society, 2015. ISBN N. [European Aerosol Conference EAC 2015. Milano (IT), 06.09.2015-11.09.2015] Institutional support: RVO:67985858 Keywords : urban pollution * aerosol processing * New Zealand Subject RIV: CF - Physical ; Theoretical Chemistry

  12. Earth tide effects on kinematic/static GPS positioning in Denmark and Greenland

    DEFF Research Database (Denmark)

    Xu, G.C.; Knudsen, Per

    2000-01-01

    demonstrating that the Earth tide effects can be viewed by GPS surveying. They are given through static GPS data static processing, static GPS data kinematic processing, and airborne kinematic GPS data processing. In these cases, the Earth tide effects can be subtracted from the GPS results. The determination......A detailed Study of the Earth tide effects on the GPS kinematic/static positioning is presented in this paper by using theoretical Earth tide computation and practical GPS data processing. Tidal effects could reach up to 30 cm in Denmark and Greenland depending on the measuring time and the...... position of reference station. With a baseline less than 80 km, the difference of the Earth tide effects could reach more than 5 mm. So, in precise applications of GPS positioning, the Earth tide effect has to be taken into account even for a relative small local GPS network. Several examples are given for...

  13. Sensitivity of aerosol direct radiative forcing to aerosol vertical profile

    OpenAIRE

    Chung, Chul E.; Choi, Jung-Ok

    2014-01-01

    Aerosol vertical profile significantly affects the aerosol direct radiative forcing at the TOA level. The degree to which the aerosol profile impacts the aerosol forcing depends on many factors such as presence of cloud, surface albedo and aerosol single scattering albedo (SSA). Using a radiation model, we show that for absorbing aerosols (with an SSA of 0.7–0.8) whether aerosols are located above cloud or below induces at least one order of magnitude larger changes of the aerosol forcing tha...

  14. Aerosols Science and Technology

    CERN Document Server

    Agranovski, Igor

    2011-01-01

    This self-contained handbook and ready reference examines aerosol science and technology in depth, providing a detailed insight into this progressive field. As such, it covers fundamental concepts, experimental methods, and a wide variety of applications, ranging from aerosol filtration to biological aerosols, and from the synthesis of carbon nanotubes to aerosol reactors.Written by a host of internationally renowned experts in the field, this is an essential resource for chemists and engineers in the chemical and materials disciplines across multiple industries, as well as ideal supplementary

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

    Science.gov (United States)

    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

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

    DEFF Research Database (Denmark)

    Sicard, Leo; Tabard, Aurelien; Ramos, Juan David Hincapie;

    2013-01-01

    platforms have to be re-developed. At the same time, smartphones are pervasive computers that users carry around and with a large pool of applications. This paper presents TIDE, a lightweight device composition middleware to bring existing smartphone applica- tions onto the tabletop. Through TIDE......’s interactive content, and an analysis of different research directions. Initial user feedback shows that TIDE is easy to use, learnable, and convenient for colla- borative activities and private environments....

  17. The impact of future sea-level rise on the tides

    OpenAIRE

    Pickering, Mark

    2014-01-01

    Tides (along with mean sea-level and surges) are a key component in coastal extreme water levels. This investigation begins by assessing the effect of future sea-level rise (SLR) on the tides of the northwest European Continental Shelf. Tides here are dominated by semidiurnal constituents; therefore the focus is on changes in the M2 constituent and the spring and neap tides. The validated operational Dutch Continental Shelf Model is run for the present day sea-level as well as uniform 2 and 1...

  18. The colors of biomass burning aerosols in the atmosphere

    Science.gov (United States)

    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.

  19. The Global S_1 Tide in Earth's Nutation

    Science.gov (United States)

    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.

  20. The oceanic tides in the South Atlantic Ocean

    Directory of Open Access Journals (Sweden)

    M. L. Genco

    Full Text Available The finite element ocean tide model of Le Provost and Vincent (1986 has been applied to the simulation of the M2 and K1 components over the South Atlantic Ocean. The discretisation of the domain, of the order of 200 km over the deep ocean, is refined down to 15 km along the coasts, such refinement enables wave propagation and damping over the continental shelves to be correctly solved. The marine boundary conditions, from Dakar to Natal, through the Drake passage and from South Africa to Antarctica, are deduced from in situ data and from Schwiderski's solution and then optimised following a procedure previously developed by the authors. The solutions presented are in very good agreement with in situ data: the root mean square deviations from a standard subset of 13 pelagic stations are 1.4 cm for M2 and 0.45 cm for K1, which is significantly better overall than solutions published to date in the literature. Zooms of the M2 solution are presented for the Falkland Archipelago, the Weddell Sea and the Patagonian Shelf. The first zoom allows detailing of the tidal structure around the Falklands and its interpretation in terms of a stationary trapped Kelvin wave system. The second zoom, over the Weddell Sea, reveals for the first time what must be the tidal signal under the permanent ice shelf and gives a solution over that sea which is generally in agreement with observations. The third zoom is over the complex Patagonian Shelf. This zoom illustrates the ability of the model to simulate the tides, even over this area, with a surprising level of realism, following purely hydrodynamic modelling procedures, within a global ocean tide model. Maps of maximum associated tidal currents are also given, as a first illustration of a by-product of these simulations.

  1. Sea-level rise impact on European shelf tide dynamics

    OpenAIRE

    Idier, Deborah; Paris, François; le Cozannet, Goneri

    2015-01-01

    Sea-level rise (SLR) affects not only the total water level, but can also modify the tidal dynamics. Several studies investigated the SLR effect on the tide of the Western European continental shelf, analysing the tidal dynamics (mainly the M2 component) for various SLR scenarios or coastal defence schemes. The present study aims at completing existing knowledge, using a modelling based approach, investigating 11 uniform SLR scenarios from-0.25 to +10m, and analysing the effect on high/low ti...

  2. Investigations of Tides from the Antiquity to Laplace

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

  4. Aerosol in the containment

    International Nuclear Information System (INIS)

    The US program LACE (LWR Aerosol Containment Experiments), in which Italy participates together with several European countries, Canada and Japan, aims at evaluating by means of a large scale experimental activity at HEDL the retention in the pipings and primary container of the radioactive aerosol released following severe accidents in light water reactors. At the same time these experiences will make available data through which the codes used to analyse the behaviour of the aerosol in the containment and to verify whether by means of the codes of thermohydraulic computation it is possible to evaluate with sufficient accuracy variable influencing the aerosol behaviour, can be validated. This report shows and compares the results obtained by the participants in the LACE program with the aerosol containment codes NAVA 5 and CONTAIN for the pre-test computations of the test LA 1, in which an accident called containment by pass is simulated

  5. Sea Spray Aerosols

    DEFF Research Database (Denmark)

    Butcher, Andrew Charles

    Aerosols are important climactically. Their specific emissions are key to reducing the uncertainty in global climate models. Marine aerosols make up the largest source of primary aerosols to the Earth's atmosphere. Uncertainty in marine aerosol mass and number flux lies in separating primary...... emissions produced directly from bubble bursting as the result of air entrainment from breaking waves and particles generated from secondary emissions of volatile organic compounds. In the first paper, we study the chemical properties of particles produced from several sea water proxies with the use of a...... cloud condensation nuclei ounter. Proxy solutions with high inorganic salt concentrations and some organics produce sea spray aerosol particles with little change in cloud condensation activity relative to pure salts. Comparison is made between a frit based method for bubble production and a plunging...

  6. Interaction of tide and salinity barrier: Limitation of numerical model

    Directory of Open Access Journals (Sweden)

    Suphat Vongvisessomjai1

    2008-07-01

    Full Text Available Nowadays, the study of interaction of the tide and the salinity barrier in an estuarine area is usually accomplished vianumerical modeling, due to the speed and convenience of modern computers. However, numerical models provide littleinsight with respect to the fundamental physical mechanisms involved. In this study, it is found that all existing numericalmodels work satisfactorily when the barrier is located at some distance far from upstream and downstream boundary conditions.Results are considerably underestimate reality when the barrier is located near the downstream boundary, usually theriver mouth. Meanwhile, this analytical model provides satisfactory output for all scenarios. The main problem of thenumerical model is that the effects of barrier construction in creation of reflected tide are neglected when specifying thedownstream boundary conditions; the use of the boundary condition before construction of the barrier which are significantlydifferent from those after the barrier construction would result in an error outputs. Future numerical models shouldattempt to account for this deficiency; otherwise, using this analytical model is another choice.

  7. Observations of internal tides in the Mozambique Channel

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  9. Artificial radioactivity in tide washed pastures in south west Scotland

    International Nuclear Information System (INIS)

    A study has been carried out to determine the impact of Sellafield discharges on the levels of radioactivity in tide washed pastures in south west Scotland. The likely areas of tidal inundations along the Nith, Urr, Dee, Fleet and Cree (including nearby Bladnoch) rivers were assessed using maps and aerials photographs. These were then visited and gamma radiation measurements taken at regular intervals to enable the external dose from anthropogenic nuclides to be estimated. A further survey followed where soil cores were taken from the areas on each river where the external dose appeared highest and analysed for a range of artificial radionuclides. The levels of 137Cs, 134Cs, 238Pu, 239+240Pu and 241Am found, although small, were clearly in excess of the background from other sources. A habit survey was carried out to provide site specific information of tide washed pasture usage, which, with the spatial radionuclide data was used to estimate doses to appropriate critical groups. The maximum annual dose calculated to arise was 60 μSv which is less than 6% of the ICRP principal dose limit of 1 mSv. (author)

  10. Earth tide effects on kinematic/static GPS positioning in Denmark and Greenland

    DEFF Research Database (Denmark)

    Xu, G.C.; Knudsen, Per

    2000-01-01

    A detailed Study of the Earth tide effects on the GPS kinematic/static positioning is presented in this paper by using theoretical Earth tide computation and practical GPS data processing. Tidal effects could reach up to 30 cm in Denmark and Greenland depending on the measuring time and the posit...

  11. Evaluation of Ocean Tide Models Used for Jason-2 Altimetry Corrections

    DEFF Research Database (Denmark)

    Fok, H.S.; Baki Iz, H.; Shum, C. K.;

    2010-01-01

    It has been more than a decade since the last comprehensive accuracy assessment of global ocean tide models. Here, we conduct an evaluation of the barotropic ocean tide corrections, which were computed using FES2004 and GOT00.2, and other models on the Jason-2 altimetry Geophysical Data Record (G...

  12. Tides in three enclosed basins: the Baltic, Black and Caspian seas

    Directory of Open Access Journals (Sweden)

    Igor P Medvedev

    2016-04-01

    Full Text Available Tides are the main type of sea level variability in the world ocean. However, oceanic tides penetrate weakly, or do not penetrate at all, into enclosed basins such as the Baltic, Black and Caspian seas. Consequently, only directly forced tides are formed in these basins. Long observation time series (up to 123 years in the Baltic Sea and 38 years in the Black and Caspian seas at numerous stations were used to precisely estimate tidal constituents. High-resolution spectra revealed fine structure of discrete peaks at tidal frequencies. The diurnal radiational constituent S1 (1 cpd, apparently associated with breeze winds, was found to play an important role in general tidal dynamics in these seas. Harmonic analysis of tides for individual yearly series with consecutive vector averaging over the entire observational period was applied to estimate mean amplitudes and phases of tidal constituents. Our findings indicate that the formation and predominance of diurnal or semidiurnal tides in these seas appears to depend on the frequency-selective properties of the basins. Thus, in the Baltic Sea with fundamental modal period of about 27 h, diurnal tides dominate in the major eastern gulfs. In the Black Sea resonant amplification of semidiurnal tides is observed in the northwestern part. The predominance of semidiurnal tides in the Caspian Sea has also probably a resonant nature. Maximum tidal heights estimated for a 100-year period are 23 cm in the Baltic Sea, 18 cm in the Black Sea and 21 cm in the southern Caspian Sea.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  16. Merging the OSIRIS and SAGE II stratospheric aerosol records

    Science.gov (United States)

    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.

  17. Observed tides at Mumbai High offshore region near the continental shelf break in the eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Joseph, A.; Vijaykumar, K.; Mehra, P.; Unnikrishnan, A.S.; Sundar, D.; Desai, R.G.P.

    ) at 15 min sampling interval using four tide gauges deployed from an oil drilling platform of the Oil and Natural Gas Corporation of India. All the four gauges provided identical measurements. The measured tides were harmonically analysed...

  18. Sugars in Antarctic aerosol

    Science.gov (United States)

    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.

  19. Tide forecasting method based on dynamic weight distribution for operational evaluation

    Institute of Scientific and Technical Information of China (English)

    Shao-wei QIU; Zeng-chuan DONG; Fen XU; Li SUN; Sheng CHEN

    2009-01-01

    Through analysis of operational evaluation factors for tide forecasting, the relationship between the evaluation factors and the weights of forecasters was examined. A tide forecasting method based on dynamic weight distribution for operational evaluation was developed, and multiple-forecaster synchronous forecasting was realized while avoiding the instability cased by only one forecaster. Weights were distributed to the forecasters according to each one's forecast precision. An evaluation criterion for the professional level of the forecasters was also built. The eligibility rates of forecast results demonstrate the skill of the forecasters and the stability of their forecasts. With the developed tide forecasting method, the precision and reasonableness of tide forecasting are improved. The application of the present method to tide forecasting at the Huangpu Park tidal station demonstrates the validity of the method.

  20. Generation and propagation of internal tides and solitary waves at the shelf edge of the Bay of Biscay

    OpenAIRE

    Xie, X. H.; Cuypers, Y.; Bouruet-Aubertot, P.; Pichon, A.; Lourenco, A.; Ferron, Bruno

    2015-01-01

    High-frequency mooring data were collected near the northern shelf edge of the Bay of Biscay to investigate the generation and propagation of internal tides and internal solitary waves (ISWs). During spring tide, strong nonlinear internal tides and large amplitude ISWs are observed every semidiurnal tidal period. While onshore propagation was expected since the mooring is located shoreward of the maximum internal tidal generation location, both onshore and seaward traveling internal tides are...

  1. Submicron aerosols: a review

    International Nuclear Information System (INIS)

    Submicron aerosols, ranging in particle diameter from 0.1 μm to 0.001 μm, and in number concentration from 10,000 to 100,000 per cm3, are more or less continuously suspended in the atmosphere we breathe. They usually require in situ measurement of concentration and size distribution with instruments such as diffusion batteries and condensation nucleus counters. Laboratory measurements require the development of submicron aerosol generators. The development of several of these devices and their use in the laboratory and field to measure radioactive as well as inactive aerosols is described

  2. Red Bull Crisis

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Additives make Red Bull the first company to test China’s new Food Safety Law "Drink Red Bull when you feel sleepy or tired" is a famous advertising slogan well-known to Chinese. But a recent German

  3. American Red Cross

    Science.gov (United States)

    ... to Help Sand Fire Evacuees » 90% of the Red Cross Workforce are Volunteers Learn More. Search for ... Volunteer» Digital Advocates» SEARCH FOR OPENINGS Shop the Red Cross Store Be Prepared and Ready to Respond ...

  4. Red Wine Over China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The color red dominates Chinese life and now growing interest in red wine maintains that trend and ushers in a new fashionable addition to local culture There was a time when trying to find a good red wine in China was a difficult affair. But as with all

  5. Non-Stationary Internal Tides Observed with Satellite Altimetry

    Science.gov (United States)

    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.

  6. Dynamical Tides in Compact White Dwarf Binaries: Influence of Rotation

    CERN Document Server

    Fuller, Jim

    2014-01-01

    Tidal interactions play an important role in the evolution and ultimate fate of compact white dwarf (WD) binaries. Not only do tides affect the pre-merger state (such as temperature and rotation rate) of the WDs, but they may also determine which systems merge and which undergo stable mass transfer. In this paper, we attempt to quantify the effects of rotation on tidal angular momentum transport in binary stars, with specific calculations applied to WD stellar models. We incorporate the effect of rotation using the traditional approximation, in which the dynamically excited gravity waves within the WDs are transformed into gravito-inertial Hough waves. The Coriolis force has only a minor effect on prograde gravity waves, and previous results predicting the tidal spin-up and heating of inspiraling WDs are not significantly modified. However, rotation strongly alters retrograde gravity waves and inertial waves, with important consequences for the tidal spin-down of accreting WDs. We identify new dynamical tidal...

  7. Electricity from wave and tide an introduction to marine energy

    CERN Document Server

    Lynn, Paul A

    2014-01-01

    This is a concise yet technically authoritative overview of modern marine energy devices with the goal of sustainable electricity generation. With 165 full-colour illustrations and photographs of devices at an advanced stage, the book provides inspiring case studies of today's most promising marine energy devices and developments, including full-scale grid-connected prototypes tested in sea conditions. It also covers the European Marine Energy Centre (EMEC) in Orkney, Scotland, where many of the devices are assessed. Topics discussed: global resources - drawing energy from the World's waves and tides history of wave and tidal stream systems theoretical background to modern developments conversion of marine energy into grid electricity modern wave energy converters and tidal stream energy converters. This book is aimed at a wide readership including professionals, policy makers and employees in the energy sector needing an introduction to marine energy. Its descriptive style and technical level will also appea...

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

    Science.gov (United States)

    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.

  9. Aerosols from biomass combustion

    Energy Technology Data Exchange (ETDEWEB)

    Nussbaumer, T.

    2001-07-01

    This report is the proceedings of a seminar on biomass combustion and aerosol production organised jointly by the International Energy Agency's (IEA) Task 32 on bio energy and the Swiss Federal Office of Energy (SFOE). This collection of 16 papers discusses the production of aerosols and fine particles by the burning of biomass and their effects. Expert knowledge on the environmental impact of aerosols, formation mechanisms, measurement technologies, methods of analysis and measures to be taken to reduce such emissions is presented. The seminar, visited by 50 participants from 11 countries, shows, according to the authors, that the reduction of aerosol emissions resulting from biomass combustion will remain a challenge for the future.

  10. Sodium oxide aerosol filtration

    International Nuclear Information System (INIS)

    In the scope of the sodium aerosol trapping research effort by the CEA/DSN, the retention capacity and yield were measured for very high efficiency fiberglass filters and several types of prefilters (cyclone agglomerator, fabric prefilters, water scrubbers). (author)

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

    Science.gov (United States)

    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.

  12. Turning the tide of public opinion on nuclear power

    International Nuclear Information System (INIS)

    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 environmentalistclose 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

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

    Science.gov (United States)

    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

  14. Measurement of the Earth tides with a MEMS gravimeter

    Science.gov (United States)

    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.

  15. Wave-Tide-Surge Coupled Simulation for Typhoon Maemi

    Institute of Scientific and Technical Information of China (English)

    Byung Ho Choi; Byung Il Min; Kyeong Ok Kim; Jin Hee Yuk

    2013-01-01

    The main task of this study focuses on studying the effect of wave-current interaction on currents,storm surge and wind wave as well as effects of current induced wave refraction and current on waves by using numerical models which consider the bottom boundary layer and sea surface roughness parameter for shallow and smooth bed area around Korean Peninsula.The coupled system (unstructured-mesh SWAN wave and ADCIRC) run on the same unstructured mesh.This identical and homogeneous mesh allows the physics of wave-circulation interactions to be correctly resolved in both models.The unstructured mesh can be applied to a large domain allowing all energy from deep to shallow waters to be seamlessly followed.There is no nesting or overlapping of structured wave meshes,and no interpolation is required.In response to typhoon Maemi (2003),all model components were validated independently,and shown to provide a faithful representation of the system's response to this storm.The waves and storm surge were allowed to develop on the continental shelf and interact with the complex nearshore environment.The resulting modeling system can be used extensively for prediction of the typhoon surge.The result show that it is important to incorporate the wave-current interaction effect into coastal area in the wave-tide-surge coupled model.At the same time,it should consider effects of depth-induced wave breaking,wind field,currents and sea surface elevation in prediction of waves.Specially,we found that:(1) wave radiation stress enhanced the current and surge elevation otherwise wave enhanced nonlinear bottom boundary layer decreased that,(2) wind wave was significantly controlled by sea surface roughness thus we cautiously took the experimental expression.The resulting modeling system can be used for hindcasting (prediction) the wave-tide-surge coupled environments at complex coastline,shallow water and fine sediment area like areas around Korean Peninsula.

  16. Emergency protection from aerosols

    International Nuclear Information System (INIS)

    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

  17. Emergency Protection from Aerosols

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. MISR Aerosol Typing

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  20. Numerical Investigation of High Tide Level Due to A Super Typhoon in A Coastal Region

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A numerical model of the coupling between astronomical tide and storm surge based on Mike 21 is applied to the coastal regions of Zhejiang Province. The model is used to simulate high tide levels combined with storm surge during 5 typhoons, including two super typhoons, that landed in the Province. In the model, the atmospheric forcing fields are calculated with parametric wind and pressure models. The computational results, with average computed errors of 13 cm for the high astronomical tide levels and 20 cm for the high storm-tide levels, show that the model yields good simulations. Typhoon No. 5612, the most intense to land in China since 1949, is taken as the typical super typhoon for the design of 5 typhoon routes, each landing at a different location along the coast. The possible extreme storm-tide levels along the coast are calculated by the model under the conditions of the 5 designed typhoon routes when they coincide with the spring tide. Results are compared with the high storm-tide levels due to the increase of the central atmospheric pressure at the base of a typical super typhoon, the change of tidal type, and the behavior of a Saomai-type typhoon. The results have practical significance for forecasting and minimization of damage during super typhoons.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

  4. Measurement and forecasting of tides of Mumbai High. Sponsored by Oil and Natural Gas Corporation

    Digital Repository Service at National Institute of Oceanography (India)

    Unnikrishnan, A.S.; Joseph, A.; Sundar, D.; Mehra, P.; VijayKumar, K.; Michael, G.S.

    . The instruments used were tide gauges (TG), Autonomous Weather Station (AWS) and self-recording current meter (RCM). A brief description of the instruments used is given in the present section. 4.1 Tide Gauge 4.1.1 Introduction Tide gauges (TG), designed... the hydrostatic pressure. The unit of pressure in mb is converted as follows. 1 mb = 1000 dyne/cm2 Using Equation (1), sea level can be estimated. 4.2 Autonomous Weather Station (AWS) As the TG measures the absolute pressure, it is necessary to measure barometric...

  5. Mapping nonlinear shallow-water tides: a look at the past and future

    DEFF Research Database (Denmark)

    Andersen, Ole Baltazar; Egbert, G.D.; Erofeeva, S.Y.;

    2006-01-01

    Overtides and compound tides are generated by nonlinear mechanisms operative primarily in shallow waters. Their presence complicates tidal analysis owing to the multitude of new constituents and their possible frequency overlap with astronomical tides. The science of nonlinear tides was greatly...... to regions with fewer in situ measurements will require improved understanding of error covariance models because these control the tradeoffs between fitting hydrodynamics and data, a delicate issue in coastal regions. While M-4 can now be robustly determined along the Topex/Poseidon satellite ground...

  6. Improved retrieval of aerosol optical thickness from MODIS measurements through derived surface reflectance over Nanjing, China

    OpenAIRE

    Zha, Yong; Wang, Qiao; Yuan, Jie; Gao, Jay; Jiang, Jianjun; Lu, Heng; Huang, Jiazhu

    2011-01-01

    Determination of surface reflectance in the red and blue channels is a critical step in retrieving aerosol optical thickness (AOT) from Moderate Resolution Imaging Spectroradiometer (MODIS) measurements. The MODIS Collection 005 (C005) aerosol algorithm uses a ratio method to determine the surface reflectance in the red (0.66 μm) and blue (0.47 μm) channels from the surface reflectance in the 2.1 μm channel using global surface reflectance relationships. In this study, we attempted to improve...

  7. Physical metrology of aerosols; Metrologie physique des aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Boulaud, D.; Vendel, J. [CEA Saclay, 91 - Gif-sur-Yvette (France). Inst. de Protection et de Surete Nucleaire

    1996-12-31

    The various detection and measuring methods for aerosols are presented, and their selection is related to aerosol characteristics (size range, concentration or mass range), thermo-hydraulic conditions (carrier fluid temperature, pressure and flow rate) and to the measuring system conditions (measuring frequency, data collection speed, cost...). Methods based on aerosol dynamic properties (inertial, diffusional and electrical methods) and aerosol optical properties (localized and integral methods) are described and their performances and applications are compared

  8. Cosmetics: colorimetric determination of zirconium in antiperspirant aerosols

    International Nuclear Information System (INIS)

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

  9. De-tiding Short Tsunami Records at DART Buoys

    Science.gov (United States)

    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

  10. Biological aerosol background characterization

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

  12. Practical analysis of tide gauges records from Antarctica

    Science.gov (United States)

    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. Mediterranean circulation response to enhanced resolution and tide

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

  15. Coherent and incoherent internal tides in the southern South China Sea

    Science.gov (United States)

    Liu, Qian; Xie, Xiaohui; Shang, Xiaodong; Chen, Guiying

    2016-03-01

    Coherent and incoherent internal tides (CITs and ICITs) in the southern South China Sea were investigated from two sets of 18-month mooring current records. The CITs were mainly composed of diurnal Q 1, O 1, P 1 and K 1 and semidiurnal M 2. The observed diurnal internal tides (ITs) were more coherent than the semidiurnal constituents. Coherent diurnal variance accounted for approximately 58% of the diurnal motion, whereas semidiurnal tides contained a much smaller fraction (35%) of coherent motion. The ICITs mainly consisted of motion at non-tidal harmonic frequencies around the tidal frequency, and showed clear intermittency. The modal decomposition of CITs and ICITs showed that CITs were dominated by mode- 1, whereas mode-1 and higher modes in ICITs signals showed comparable amplitudes. CITs and ICITs accounted for approximately 64% and 36% of the total kinetic energy of internal tides, respectively.

  16. Fish and logger summaries - Physical and biological effects of fish-friendly tide gates

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The purpose of this one-time stand-alone study is to evaluate how effective "fish-friendly" or self-regulating tide gates (SRTs) are at increasing connectivity for...

  17. Data logger database - Physical and biological effects of fish-friendly tide gates

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The purpose of this one-time stand-alone study is to evaluate how effective "fish-friendly" or self-regulating tide gates (SRTs) are at increasing connectivity for...

  18. Astronomical High Tide Line, Geographic NAD83, NWRC (1995) [hightide_line_NWRC_1995

    Data.gov (United States)

    Louisiana Geographic Information Center — The astronomical high tide line was compiled from National Wetlands Inventory (NWI) 1:24,000-scale habitat maps that were photo-interpreted from color-infrared...

  19. Spin evolution of Earth-sized exoplanets, including atmospheric tides and core-mantle friction

    CERN Document Server

    Cunha, Diana; Laskar, Jacques

    2014-01-01

    Planets with masses between 0.1 - 10 M_earth are believed to host dense atmospheres. These atmospheres can play an important role on the planet's spin evolution, since thermal atmospheric tides, driven by the host star, may counterbalance gravitational tides. In this work we study the long-term spin evolution of Earth-sized exoplanets. We generalize previous works by including the effect of eccentric orbits and obliquity. We show that under the effect of tides and core-mantle friction, the obliquity of the planets evolve either to 0 or 180 degrees. The rotation of these planets is also expected to evolve into a very restricted number of equilibrium configurations. In general, none of this equilibria is synchronous with the orbital mean motion. The role of thermal atmospheric tides becomes more important for Earth-sized planets in the habitable zones of their systems, so they cannot be neglected when we search for their potential habitability.

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    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...... 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...

  1. A technique to circumvent lower density water trapping by tide-wells

    Digital Repository Service at National Institute of Oceanography (India)

    Joseph, A.; VijayKumar, K.; Desa, E.S.; Desa, E.; Peshwe, V.B.

    the Bernoulli dynamic pressure effects. Density measurements during different seasons indicate that these performations allow free exchange of waters within and outside the tide-well, improving measuring accuracy, but slightly increasing wave effects in the well...

  2. Fish community responses to green tides in shallow estuarine and coastal areas

    Science.gov (United States)

    Le Luherne, E.; Réveillac, E.; Ponsero, A.; Sturbois, A.; Ballu, S.; Perdriau, M.; Le Pape, O.

    2016-06-01

    All over the world, numerous bays and estuarine systems that are known to shelter essential fish habitats are experiencing proliferations of green macroalgae known as green tides. Although the processes that enhance green tides in response to nutrient enrichment are well known, their consequences for ecological communities -especially for ichthyofauna- remain poorly studied. To estimate these consequences, this analysis focused on the two types of shallow systems that are experiencing green tides: sandy beaches and estuarine mudflats. In these two systems, macroalgae proliferation and fish community were surveyed along seasonal cycles at control and impacted sites that shared similar physico-chemical parameters and sediment structure. To analyse the consequences of green tides on the fish community, a Before-After Control-Impact approach was used. This approach reveals no difference between fish communities at the control and impacted sites before the macroalgal bloom. Then, it underlines an influence of green tides on the fish community, and this influence varies according to the composition, density and duration of the macroalgal bloom. Indeed, when intertidal systems experienced short proliferation and/or weak density, green tides did not seem to impact the fish community. However, when green macroalgae proliferated in large quantities and/or when the proliferation lasted for long periods, the fish community was significantly affected. These modifications in the fish community led to a significant decrease in fish species diversity and density until fish disappeared from impacted sites at high proliferations. Furthermore, the response of fish species to green tides differed according to their functional guilds. Negative consequences for benthic and marine juvenile fish species were beginning at low proliferations, whereas for pelagic fish species they occurred only at high proliferations. Thus, green tides significantly affect fish habitat suitability because

  3. Amplified Msf tides at Kochi backwaters on the southwest coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Joseph, A.; Balachandran, K.K.; Mehra, P.; Desai, R.G.P.; VijayKumar, K.; Agarvadekar, Y.; Revichandran, C.; Dabholkar, N.

    plays an addi- tional role in the Msf tidal amplification. Keywords: Amplification, bed materials, Kochi back- waters, nonlinear frictional interaction, shallowness, tides. NOTICEABLE transformations occur in the pattern and range of tides... during their propagation from the open ocean into continental shelves and further into shallower coastal waters, broad lagoons and backwaters. Such trans- formations, caused by a myriad of topographical and bathymetric influences, are indicated...

  4. On the Imminent Regional Seismic Activity Forecasting Using INTERMAGNET and Sun-Moon Tide Code Data

    OpenAIRE

    Mavrodiev, Strachimir Cht.; Pekevski, Lazo; Kikuashvili, Giorgi; Botev, Emil; Getsov, Petar; Mardirossian, Garo; Sotirov, Georgi; Teodossiev, Dimitar

    2016-01-01

    In this paper we present an approach for forecasting the imminent regional seismic activity by using geomagnetic data and Earth tide data. The time periods of seismic activity are the time periods around the Sun-Moon extreme of the diurnal average value of the tide vector module. For analyzing the geomagnetic data behaviour we use diurnal standard deviation of geomagnetic vector components F for calculating the time variance Geomag Signal. The Sun storm influence is avoided by using data for ...

  5. Triggering of Aftershocks of the Japan 2011 Earthquake by Earth Tides

    CERN Document Server

    Datta, Arjun

    2011-01-01

    The aftershock sequence of the devastating Japan earthquake of March 2011 is analyzed for the presence of periodicities at the Earth tide periods. We use spectral analysis as well as a time-domain method KORRECT developed earlier to detect presence of diurnal and semi-diurnal periodicities in the sequence of aftershocks (M \\geq 4). This suggests that large aftershocks in the fault zone of the Japan 2011 earthquake were strongly influenced by Earth tides.

  6. Inquiring into Red/Red Inquiring

    Directory of Open Access Journals (Sweden)

    Ken Gale

    2013-05-01

    Full Text Available This layered account of an inquiry into ‘red’ emerged out of a collective biography workshop. In the middle of the Wiltshire countryside, an international and interdisciplinary group of scholars gathered together to write and make other things and marks on paper that asked questions of, and into, the spaces between words, people, things and their environments. We did not set out to workshop or write into or paint ‘red’ but, rather, it was red that slipped in, uninvited, and painted and wrote us. Red arose as a blush or a stain seeping amongst us that became referenced obliquely by material objects, metaphors and fairytales. The stain spread, became noticeable through our weekend together and beyond it, creating another (bright red artery vein of connection to write with.

  7. Angular momentum budget of the radiational S1 ocean tide

    Science.gov (United States)

    Schindelegger, Michael; Dobslaw, Henryk; Poropat, Lea; Salstein, David; Böhm, Johannes

    2016-04-01

    The balance of diurnal S1 oceanic angular momentum (OAM) variations through torques at the sea surface and the bottom topography is validated using both a barotropic and a baroclinic numerical tide model. This analysis discloses the extent to which atmosphere-driven S1 forward simulations are reliable for use in studies of high-frequency polar motion and changes in length-of-day. Viscous and dissipative torques associated with wind stress, bottom friction, as well as internal tidal energy conversion are shown to be small, and they are overshadowed by gravitational and pressure-related interaction forces. In particular, the zonal OAM variability of S1 is almost completely balanced by the water pressure torque on the local bathymetry, whereas in the prograde equatorial case also the air pressure torque on the seafloor as well as ellipsoidal contributions from the non-spherical atmosphere and solid Earth must be taken into account. Overall, the OAM budget is well closed in both the axial and the equatorial directions, thus allowing for an identification of the main diurnal angular momentum sinks in the ocean. The physical interaction forces are found to be largest at shelf breaks and continental slopes in low latitudes, with the most dominant contribution coming from the Indonesian archipelago.

  8. Vertical land movements from the combined use of satellite altimetry and tide gauges

    Science.gov (United States)

    Marcos, Marta; Woppelmann, Guy

    2015-04-01

    Vertical ground displacements at tide gauge sites were estimated from the differenced time series of monthly satellite altimetry sea level anomalies minus tide gauge. We have used the time series of satellite altimetry that are routinely processed and distributed by four major data providers (three gridded and one along-track products) together with monthly tide gauge records from the datum controlled data set of the Permanent Service for Mean Sea Level (PSMSL). Differenced time series were built using three variants of altimetric time series. Each resulting record was analyzed assuming a combination of white noise and power-law noise of a priori unknown spectral index. The rate uncertainties, computed taking into account the noise content in the differenced time series, will be discussed. In particular, in the context of the departures from the white noise (expected only if both the satellite altimeter and the tide gauge were recording mostly the same sea level signals and their instrumental errors were negligible) and its amplitude. The most suitable altimetric product in terms of correlation and variance reduction at tide gauges, among those investigated, will be identified. Rates of vertical land motion computed with Global Positioning System (GPS) and rates obtained from the combination of altimetry and tide gauge records will be finally compared for those stations where both measurements are available.

  9. The impact of global sea-level rise on tides: a revisit

    Science.gov (United States)

    Carless, Stacey; Green, Mattias; Wilmes, Sophie

    2015-04-01

    As a result of climate change sea level rise is expected globally. However, the predicted change in sea level is unlikely to be linear or uniform along our coastlines, with some regions more at risk than others. A number of papers have recently highlighted how regional tides may change with relatively large levels of future sea-level, but global estimates of the impact of SLR on tides are sparse, or have shown that the models at the time were not accurate enough to reproduce existing signals in the tide gauge record. The tide gauge record in many place now span a century or more, and thus observe both relative sea level rise and trends in tidal amplitudes. It is thus be possible, with the latest global tidal models, to investigate if the models capture the observed signals when subject to realistic levels of SLR. To ensure enough resolution we investigated the response of the tides to sea-level change in a number of shelf seas around the globe. The trends in the tidal amplitudes were then compared to those seen in the PSMSL long-term tide gauge record, and shown to agree fairly well. The main conclusion is that in order to accurately capture change sin tidal amplitudes in the future we must simulate tidal changes for each individual shelf sea - only then can we predict and mitigate future change.

  10. INVESTIGATON OF SEA LEVEL CHANGE ALONG THE BLACK SEA COAST FROM TIDE GAUGE AND SATELLITE ALTIMETRY

    Directory of Open Access Journals (Sweden)

    N. B. Avsar

    2015-12-01

    Full Text Available In this study, we focus on sea level changes along the Black Sea coast. For this purpose, at same observation period the linear trends and the components of seasonal variations of sea level change are estimated at 12 tide gauge sites (Amasra, Igneada, Trabzon-II, Sinop, Sile, Poti, Batumi, Sevastopol, Tuapse, Varna, Bourgas, and Constantza located along the Black Sea coast and available altimetric grid points closest to the tide gauge locations. The consistency of the results derived from both observations are investigated and interpreted. Furthermore, in order to compare the trends at the same location, it is interpolated from the trends obtained at the altimetric grid points in the defined neighbouring area with a diameter of 0.125° using a weighted average interpolation algorithm at each tide gauge site. For some tide gauges such as Sevastopol, Varna, and Bourgas, it is very likely that the trend estimates are not reliable because the time-spans overlapping the altimeter period are too short. At Sile, the long-term change for the time series of both data types do not give statistically significant linear rates. However, when the sites have long-term records, a general agreement between the satellite altimetry and tide gauge time series is observed at Poti (~20 years and Tuapse (~18 years. On the other hand, the difference of annual phase between satellite altimetry and tide gauge results is from 1.32° to 71.48°.

  11. Investigaton of Sea Level Change Along the Black Sea Coast from Tide Gauge and Satellite Altimetry

    Science.gov (United States)

    Avsar, N. B.; Kutoglu, S. H.; Jin, S.; Erol, B.

    2015-12-01

    In this study, we focus on sea level changes along the Black Sea coast. For this purpose, at same observation period the linear trends and the components of seasonal variations of sea level change are estimated at 12 tide gauge sites (Amasra, Igneada, Trabzon-II, Sinop, Sile, Poti, Batumi, Sevastopol, Tuapse, Varna, Bourgas, and Constantza) located along the Black Sea coast and available altimetric grid points closest to the tide gauge locations. The consistency of the results derived from both observations are investigated and interpreted. Furthermore, in order to compare the trends at the same location, it is interpolated from the trends obtained at the altimetric grid points in the defined neighbouring area with a diameter of 0.125° using a weighted average interpolation algorithm at each tide gauge site. For some tide gauges such as Sevastopol, Varna, and Bourgas, it is very likely that the trend estimates are not reliable because the time-spans overlapping the altimeter period are too short. At Sile, the long-term change for the time series of both data types do not give statistically significant linear rates. However, when the sites have long-term records, a general agreement between the satellite altimetry and tide gauge time series is observed at Poti (~20 years) and Tuapse (~18 years). On the other hand, the difference of annual phase between satellite altimetry and tide gauge results is from 1.32° to 71.48°.

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

    Science.gov (United States)

    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). 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.

  13. Experimental information: 1096 [RED

    Lifescience Database Archive (English)

    Full Text Available 1000_24_4_3 RED Cy3 Cy5 Zenpei Shimatnai Society for Techno-Innovation of Agriculture, Forestry ... ries Hormonal Other Hormonal Other Rice Expression Database ,RED,Time course,Jasmonic acid,JA two-dye methods 2 ...

  14. Experimental information: 1083 [RED

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    Full Text Available 1000_22_6_5 RED Cy3 Cy5 Kanako Shinbo Society for Techno-innovation of Agriculture,Forestry and ... Fisheries Hormonal Hormonal Rice Expression Database ,RED,Time course,Gibberellin,GA3 two-dye methods 20 ...

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  16. Experimental information: 1101 [RED

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    Full Text Available 1000_24_14_13 RED Cy3 Cy5 Zenpei Shimatnai Society for Techno-Innovation of Agriculture, Forestr ... ries Hormonal Other Hormonal Other Rice Expression Database ,RED,Time course,Jasmonic acid,JA two-dye methods 2 ...

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    Full Text Available 1000_23_8_7 RED Cy3 Cy5 Kanako Shinbo Society for Techno-innovation of Agriculture,Forestry and ... ries Hormonal Other Hormonal Other Rice Expression Database ,RED,Time course,Brassinosteroide,Br two-dye method ...

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  20. Experimental information: 1082 [RED

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    Full Text Available 1000_22_4_3 RED Cy3 Cy5 Kanako Shinbo Society for Techno-innovation of Agriculture,Forestry and ... Fisheries Hormonal Hormonal Rice Expression Database ,RED,Time course,Gibberellin,GA3 two-dye methods 20 ...

  1. Experimental information: 1097 [RED

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    Full Text Available 1000_24_6_5 RED Cy3 Cy5 Zenpei Shimatnai Society for Techno-Innovation of Agriculture, Forestry ... ries Hormonal Other Hormonal Other Rice Expression Database ,RED,Time course,Jasmonic acid,JA two-dye methods 2 ...

  2. Experimental information: 1100 [RED

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  4. Experimental information: 1088 [RED

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  5. Experimental information: 1090 [RED

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    Full Text Available 1000_23_6_5 RED Cy3 Cy5 Kanako Shinbo Society for Techno-innovation of Agriculture,Forestry and ... ries Hormonal Other Hormonal Other Rice Expression Database ,RED,Time course,Brassinosteroide,Br two-dye method ...

  6. Experimental information: 1076 [RED

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  8. Experimental information: 1084 [RED

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  9. Experimental information: 1087 [RED

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    Full Text Available 1000_22_14_13 RED Cy3 Cy5 Kanako Shinbo Society for Techno-innovation of Agriculture,Forestry an ... d Fisheries Hormonal Hormonal Rice Expression Database ,RED,Time course,Gibberellin,GA3 two-dye methods 20 ...

  10. Experimental information: 1094 [RED

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  11. Experimental information: 1089 [RED

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  12. Experimental information: 1075 [RED

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  20. Experimental information: 1093 [RED

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  1. Probe data: 5652 [RED

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    Full Text Available R02-002330-1AR RED D41273 AU174297 ST3645 >AGU83687_1(U83687|pid:g1835701) Apium graveolens NADP ... H-dependent mannose 6-phosphate ... reductase (m6pr) mRNA, complete cds; aldo-keto red ... uctase; similar to aldose 6-phosphate ... reductase also known as NADP-sorbitol-6-phosphate ...

  2. EFFECTS OF OCEAN TIDE MODELS ON GNSS-ESTIMATED ZTD AND PWV IN TURKEY

    Directory of Open Access Journals (Sweden)

    G. Gurbuz

    2015-12-01

    Full Text Available Global Navigation Satellite System (GNSS observations can precisely estimate the total zenith tropospheric delay (ZTD and precipitable water vapour (PWV for weather prediction and atmospheric research as a continuous and all-weather technique. However, apart from GNSS technique itself, estimations of ZTD and PWV are subject to effects of geophysical models with large uncertainties, particularly imprecise ocean tide models in Turkey. In this paper, GNSS data from Jan. 1st to Dec. 31st of 2014 are processed at 4 co-located GNSS stations (GISM, DIYB, GANM, and ADAN with radiosonde from Turkish Met-Office along with several nearby IGS stations. The GAMIT/GLOBK software has been used to process GNSS data of 30-second sample using the Vienna Mapping Function and 10° elevation cut-off angle. Also tidal and non-tidal atmospheric pressure loadings (ATML at the observation level are also applied in GAMIT/GLOBK. Several widely used ocean tide models are used to evaluate their effects on GNSS-estimated ZTD and PWV estimation, such as IERS recommended FES2004, NAO99b from a barotropic hydrodynamic model, CSR4.0 obtained from TOPEX/Poseidon altimetry with the model FES94.1 as the reference model and GOT00 which is again long wavelength adjustments of FES94.1 using TOPEX/Poseidon data at 0.5 by 0.5 degree grid. The ZTD and PWV computed from radiosonde profile observations are regarded as reference values for the comparison and validation. In the processing phase, five different strategies are taken without ocean tide model and with four aforementioned ocean tide models, respectively, which are used to evaluate ocean tide models effects on GNSS-estimated ZTD and PWV estimation through comparing with co-located Radiosonde. Results showed that ocean tide models have greatly affected the estimation of the ZTD in centimeter level and thus the precipitable water vapour in millimeter level, respectively at stations near coasts. The ocean tide model FES2004 that is

  3. Geographical distribution of red and green Noctiluca scintillans

    Science.gov (United States)

    Harrison, P. J.; Furuya, K.; Glibert, P. M.; Xu, J.; Liu, H. B.; Yin, K.; Lee, J. H. W.; Anderson, D. M.; Gowen, R.; Al-Azri, A. R.; Ho, A. Y. T.

    2011-07-01

    The dinoflagellate Noctiluca scintillans is one of the most important and abundant red tide organisms and it is distributed world-wide. It occurs in two forms. Red Noctiluca is heterotrophic and fills the role of one of the microzooplankton grazers in the foodweb. In contrast, green Noctiluca contains a photosynthetic symbiont Pedinomonas noctilucae (a prasinophyte), but it also feeds on other plankton when the food supply is abundant. In this review, we document the global distribution of these two forms and include the first maps of their global distribution. Red Noctiluca occurs widely in the temperate to sub-tropical coastal regions of the world. It occurs over a wide temperature range of about 10°C to 25°C and at higher salinities (generally not in estuaries). It is particularly abundant in high productivity areas such as upwelling or eutrophic areas where diatoms dominate since they are its preferred food source. Green Noctiluca is much more restricted to a temperature range of 25°C-30°C and mainly occurs in tropical waters of Southeast Asia, Bay of Bengal (east coast of India), in the eastern, western and northern Arabian Sea, the Red Sea, and recently it has become very abundant in the Gulf of Oman. Red and green Noctiluca do overlap in their distribution in the eastern, northern and western Arabian Sea with a seasonal shift from green Noctiluca in the cooler winter convective mixing, higher productivity season, to red Noctiluca in the more oligotrophic warmer summer season.

  4. Tidal asymmetry in a funnel-shaped estuary with mixed semidiurnal tides

    Science.gov (United States)

    Gong, Wenping; Schuttelaars, Henk; Zhang, Heng

    2016-03-01

    Different types of tidal asymmetry (see review of de Swart and Zimmerman Annu Rev Fluid Mech 41: 203-229, 2009) are examined in this study. We distinguish three types of tidal asymmetry: duration and magnitude differences between flood and ebb tidal flow, duration difference between the rising and falling tides. For waterborne substance transport, the first two asymmetries are important while the last one is not. In this study, we take the Huangmaohai Estuary (HE), Pearl River Delta, China as an example to examine the spatio-temporal variations of the tidal asymmetry in a mixed semidiurnal tidal regime and to explain them by investigating the associated mechanisms. The methodology defining the tidal duration asymmetry and velocity skewness, proposed by Nidzieko (J Geophys Res 115: C08006. doi: 10.1029/2009JC005864, 2010) and synthesized by Song et al. (J Geophys Res 116: C12007. doi: 10.1029/2011JC007270, 2011), is utilized here and referred to as tidal duration asymmetry (TDA) and flow velocity asymmetry (FVA), respectively. The methodology is further used to quantify the flow duration asymmetry (FDA). A positive asymmetry means a shorter duration of low water slack for FDA, a shorter duration of the rising tide for TDA, and a flood dominance for FVA and vice versa. The Regional Ocean Modeling System (ROMS) model is used to provide relatively long-term water elevation and velocity data and to conduct diagnostic experiments. In the HE, the main tidal constituents are diurnal tides K 1, O 1 and semidiurnal tides M 2 and S 2. The interaction among the diurnal and semidiurnal tides generates a negative tidal asymmetry, while the interactions among semidiurnal tides and their overtides or compound tides result in a positive tidal asymmetry. The competition among the above interactions determines the FDA and TDA, whereas for the FVA, aside from the interaction among different tidal constituents, an extra component, the residual flow, plays an important role. The results

  5. Tidal asymmetry in a funnel-shaped estuary with mixed semidiurnal tides

    Science.gov (United States)

    Gong, Wenping; Schuttelaars, Henk; Zhang, Heng

    2016-05-01

    Different types of tidal asymmetry (see review of de Swart and Zimmerman Annu Rev Fluid Mech 41: 203-229, 2009) are examined in this study. We distinguish three types of tidal asymmetry: duration and magnitude differences between flood and ebb tidal flow, duration difference between the rising and falling tides. For waterborne substance transport, the first two asymmetries are important while the last one is not. In this study, we take the Huangmaohai Estuary (HE), Pearl River Delta, China as an example to examine the spatio-temporal variations of the tidal asymmetry in a mixed semidiurnal tidal regime and to explain them by investigating the associated mechanisms. The methodology defining the tidal duration asymmetry and velocity skewness, proposed by Nidzieko (J Geophys Res 115: C08006. doi: 10.1029/2009JC005864 , 2010) and synthesized by Song et al. (J Geophys Res 116: C12007. doi: 10.1029/2011JC007270 , 2011), is utilized here and referred to as tidal duration asymmetry (TDA) and flow velocity asymmetry (FVA), respectively. The methodology is further used to quantify the flow duration asymmetry (FDA). A positive asymmetry means a shorter duration of low water slack for FDA, a shorter duration of the rising tide for TDA, and a flood dominance for FVA and vice versa. The Regional Ocean Modeling System (ROMS) model is used to provide relatively long-term water elevation and velocity data and to conduct diagnostic experiments. In the HE, the main tidal constituents are diurnal tides K 1, O 1 and semidiurnal tides M 2 and S 2. The interaction among the diurnal and semidiurnal tides generates a negative tidal asymmetry, while the interactions among semidiurnal tides and their overtides or compound tides result in a positive tidal asymmetry. The competition among the above interactions determines the FDA and TDA, whereas for the FVA, aside from the interaction among different tidal constituents, an extra component, the residual flow, plays an important role. The

  6. 17 years of aerosol and clouds from the ATSR Series of Instruments

    Science.gov (United States)

    Poulsen, C. A.

    2015-12-01

    Aerosols play a significant role in Earth's climate by scattering and absorbing incoming sunlight and affecting the formation and radiative properties of clouds. The extent to which aerosols affect cloud remains one of the largest sources of uncertainty amongst all influences on climate change. Now, a new comprehensive datasets has been developed under the ESA Climate Change Initiative (CCI) programme to quantify how changes in aerosol levels affect these clouds. The unique dataset is constructed from the Optimal Retrieval of Aerosol and Cloud (ORAC) algorithm used in (A)ATSR (Along Track Scanning Radiometer) retrievals of aerosols generated in the Aerosol CCI and the CC4CL ( Community Code for CLimate) for cloud retrieval in the Cloud CCI. The ATSR instrument is a dual viewing instrument with on board visible and infra red calibration systems making it an ideal instrument to study trends of Aerosol and Clouds and their interactions. The data set begins in 1995 and ends in 2012. A new instrument in the series SLSTR(Sea and Land Surface Temperature Radiometer) will be launch in 2015. The Aerosol and Clouds are retreived using similar algorithms to maximise the consistency of the results These state-of-the-art retrievals have been merged together to quantify the susceptibility of cloud properties to changes in aerosol concentration. Aerosol-cloud susceptibilities are calculated from several thousand samples in each 1x1 degree globally gridded region. Two-D histograms of the aerosol and cloud properties are also included to facilitate seamless comparisons between other satellite and modelling data sets. The analysis of these two long term records will be discussed individually and the initial comparisons between these new joint products and models will be presented.

  7. Tide distortion and attenuation in an Amazonian tidal river

    Directory of Open Access Journals (Sweden)

    Paulo T. A. Freitas

    2012-12-01

    Full Text Available The present study seeks to evaluate tidal propagation in the Guamá-Capim river system, in the Amazonian region, considering hydrodynamic and geomorphological aspects. Available data sets on fluvial discharge and water level variations were considered, besides several methods of measuring the tides (currents, water levels and discharges recorded at different stations and in different periods. The main point argued is that fluvial discharge is the key-factor in tidal distortion and tidal bore formation in the system investigated, whereas the low relief of the area would be the main factor contributing to landward tidal incursion. The results show an impressive upward tidal incursion of more than 200 km, including substantial distortion -increasing upstream -of the tidal wave, of which the ebb phase lasts up to 5 hours longer than the flood, including higher flood current velocities as far as 161 km upstream. Generally, only hyposynchronous tidal response was observed. Seasonally, the fluvial discharge varies about 10 times in the Guamá and 4 times in the Capim River. The increase of the fluvial discharge results in an increasing distortion of the tide, besides a weak increase of the attenuation. During high fluvial discharge periods in conjunction with equinoctial tides (e.g. March-April, a tidal bore occurs in the system, also increased by the generally low relief. Therefore, the conclusions include: low relief and the distortion related to high fluvial discharges are the main factors controlling tidal propagation along the system and tidal bore formation. Furthermore, the system could be classified as a tidal river, in which massive regional fresh water input results in virtually non-existent salinity throughout the Guamá-Capim system.O presente estudo teve como objetivo investigar a propagação da maré no sistema fluvial Guamá-Capim, na região amazônica, considerando aspectos hidrológicos e geomorfológicos. Os métodos empregados

  8. Numerical study of the tides and residual currents in the Qiongzhou Strait

    Institute of Scientific and Technical Information of China (English)

    CHEN Changlin; LI Peiliang; SHI Maochong; ZUO Juncheng; CHEN Meixiang; SUN Haiping

    2009-01-01

    Based on the three-dimensional ECOM model, the tide, tide-induced residual current, wind-driven and density currents in the Beibu (Tonkin) Gulf and Qiongzhou Strait are diagnostically computed in fine grid. The tides and tidal currents in the Beibu Gulf and Qiongzhou Strait are well reproduced. The model results show that the semidiurnal tidal wave propagates eastward from the Beibu Gulf through Qiongzhou Strait, while diurnal tidal waves enter the strait from both the eastern and western sides and interact on the southeast coast of the strait. The formation processes of the residual currents in Qiongzhou Strait in summer (August) and winter (January) are mainly discussed. It is shown that the total residual currents (coupling effect of wind, tide and density) in the strait are westward in both summer and winter. The water volume transported from the east to west into the Beibu Gulf is 0.026 Sv in summer and 0.116 Sv in winter. Numerical experiments indicate that the dominant factor affecting the residual currents in the strait is not the wind stress but the tidal rectification. The westward tide-induced residual current, driven by the tidal rectification, is rather strong in the strait with water volume transport of 0.063 Sv. The wind in summer only reduces the westward tide-induced residual current to a certain extent, and the wind in winter approximately doubles the westward tide-induced residual current through the strait. The density current contributes little to the total residual current in both summer and winter.

  9. Tidal Tomography: Constraining Long-Wavelength Deep Mantle Structure Using Earth's Body Tide Signal

    Science.gov (United States)

    Lau, H. C. P.; Yang, H. Y.; Tromp, J.; Mitrovica, J. X.; Davis, J. L.; Latychev, K.

    2014-12-01

    Luni-solar gravitational forcing drives the Earth's body-tide response over periods ranging from 8 hours to 18.6 years, a timespan that extends far beyond the seismic band. A finite volume numerical study of body tides in the semi-diurnal (SD) band by Latychev et al. (2008; EPSL) demonstrated that aspherical density and elastic structure inferred from seismic tomography perturbed the radial crustal displacement response by ~1 mm, a level at which they can be observed with modern space-geodetic inferences of body tide signals (Yuan et al., 2012; EPSL). Thus, site-specific estimates of the body-tide response to the known luni-solar forcing potentially provides a new, independent and powerful method for probing long-wavelength, deep mantle structure. To this end, we have used advances in seismic free oscillation theory to derive a new normal mode treatment of the SD body tide response of an aspherical, rotating and anelastic Earth. The accuracy of the theory is demonstrated by benchmarking our body tide predictions against both finite volume treatments of aspherical structure and previous theoretical and observational constraints on the effects of anelasticity. We begin by summarizing these results, as well as a series of synthetic tests that indicate that the body tide response is particularly sensitive to long wavelength, deep mantle structure - a sensitivity that is ideal for investigating the elastic and density structure of the two large low shear velocity provinces (LLSVPs) that exist below the Pacific and southern Africa. Finally, we also present results from a first tidal analysis of the integrated density of the LLSVPs and discuss the implications of these results for the ongoing debate concerning the relative size of thermal and chemical effects on these structures, their net buoyancy and longevity.

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

    Science.gov (United States)

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

    2014-05-01

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

  11. Determination of ocean tides from the first year of TOPEX/POSEIDON altimeter measurements

    Science.gov (United States)

    Ma, X. C.; Shum, C. K.; Eanes, R. J.; Tapley, B. D.

    1994-01-01

    An improved geocentric global ocean tide model has been determined using 1 year of TOPEX/POSEIDON altimeter measurements to provide corrections to the Cartwright and Ray (1991) model (CR91). The corrections were determined on a 3 deg x 3 deg grid using both the harmonic analysis method and the response method. The two approaches produce similar solutions. The effect on the tide solution of simultaneously adjusting radial orbit correction parameters using altimeter measurements was examined. Four semidiurnal (N(sub 2), M(sub 2), S(sub 2) and K(sub 2)), four diurnal (Q(sdub 1), O(sub 1), P(sub 1), and K(sub 1)), and three long-period (S(sub sa), M(sub m), and M(sub f)) constituents, along with the variations at the annual frequency, were included in the harmomnic analysis solution. The observed annual variations represents the first global measurement describing accurate seasonal changes of the ocean during an El Nino year. The corrections to the M(sub 2) constituent have an root mean square (RMS) of 3.6 cm and display a clear banding pattern with regional highs and lows reaching 8 cm. The improved tide model reduces the weighted altimeter crossover residual from 9.8 cm RMS, when the CR91 tide model is used, to 8.2 cm on RMS. Comparison of the improved model to pelagic tidal constants determined from 80 tide gauges gives RMS differences of 2.7 cm for M(sub 2) and 1.7 cm for K(sub 1). Comparable values when the CR91 model is used are 3.9 cm and 2.0 cm, respectively. Examination of TOPEX/POSEIDON sea level anomaly variations using the new tide model further confirms that the tide model has been improved.

  12. A one-dimensional diffusion analogy model for estimation of tide heights in selected tidal marshes in Connecticut

    Science.gov (United States)

    Bjerklie, David M.; O’Brien, Kevin; Rozsa, Ron

    2013-01-01

    A one-dimensional diffusion analogy model for estimating tide heights in coastal marshes was developed and calibrated by using data from previous tidal-marsh studies. The method is simpler to use than other one- and two-dimensional hydrodynamic models because it does not require marsh depth and tidal prism information; however, the one-dimensional diffusion analogy model cannot be used to estimate tide heights, flow velocities, and tide arrival times for tide conditions other than the highest tide for which it is calibrated. Limited validation of the method indicates that it has an accuracy within 0.3 feet. The method can be applied with limited calibration information that is based entirely on remote sensing or geographic information system data layers. The method can be used to estimate high-tide heights in tidal wetlands drained by tide gates where tide levels cannot be observed directly by opening the gates without risk of flooding properties and structures. A geographic information system application of the method is demonstrated for Sybil Creek marsh in Branford, Connecticut. The tidal flux into this marsh is controlled by two tide gates that prevent full tidal inundation of the marsh. The method application shows reasonable tide heights for the gates-closed condition (the normal condition) and the one-gate-open condition on the basis of comparison with observed heights. The condition with all tide gates open (two gates) was simulated with the model; results indicate where several structures would be flooded if the gates were removed as part of restoration efforts or if the tide gates were to fail.

  13. The earthly world and the red chambers : Qing women's self-representation and mediations with traditions in their writings on the Dream of the red chamber

    OpenAIRE

    Zhu, Fan; 朱凡

    2013-01-01

    This thesis studies the Qing women’s writings on the Dream of the Red Chamber. Qing women’s comments on the novel formed an important aspect of the second high tide of women’s literature in late imperial China. By examining these writings, I intend to reveal how the women authors mediated with the Confucian morality and how they exerted influence on the literary tradition from its inside. I also intend to examine the women authors’ self-representations and their reflections on the actual worl...

  14. Efficacy of aerosol applications of methoprene and synergized pyrethrin against Tribolium castaneum adults and eggs

    Science.gov (United States)

    Experiments were performed to determine the efficacy of a single aerosol application of the insecticides methoprene and piperonyl butoxide-synergized pyrethrin, alone or in combination, and the insecticide carrier, Isopar M, against Tribolium castaneum (Herbst), the red flour beetle. The initial tes...

  15. Properties of Red Sea coastal currents

    KAUST Repository

    Churchill, J.H.

    2014-02-14

    Properties of coastal flows of the central Red Sea are examined using 2 years of velocity data acquired off the coast of Saudi Arabia near 22 °N. The tidal flow is found to be very weak. The strongest tidal constituent, the M2 tide, has a magnitude of order 4 cm s−1. Energetic near-inertial and diurnal period motions are observed. These are surface-intensified currents, reaching magnitudes of >10 cm s−1. Although the diurnal currents appear to be principally wind-driven, their relationship with the surface wind stress record is complex. Less than 50% of the diurnal current variance is related to the diurnal wind stress through linear correlation. Correlation analysis reveals a classical upwelling/downwelling response to the alongshore wind stress. However, less than 30% of the overall sub-inertial variance can be accounted for by this response. The action of basin-scale eddies, impinging on the coastal zone, is implicated as a primary mechanism for driving coastal flows.

  16. Next generation red teaming

    CERN Document Server

    Dalziel, Henry

    2015-01-01

    Red Teaming is can be described as a type of wargaming.In private business, penetration testers audit and test organization security, often in a secretive setting. The entire point of the Red Team is to see how weak or otherwise the organization's security posture is. This course is particularly suited to CISO's and CTO's that need to learn how to build a successful Red Team, as well as budding cyber security professionals who would like to learn more about the world of information security. Teaches readers how to dentify systemic security issues based on the analysis of vulnerability and con

  17. Inteligencia de red

    OpenAIRE

    Barba Martí, Antonio; Hesselbach Serra, Xavier

    2002-01-01

    Bibliografia Actualmente existe una necesidad cada vez mayor de ofrecer servicios de red avanzados, que proporcionen un alto valor añadido al cliente. Eso es ya posible gracias a las nuevas capacidades de computación añadidas a los nodos de red, que proporcionan inteligencia y facilitan la gestión de red a los operadores y proveedores de servicios. En este texto, se presentan las nuevas redes inteligentes basadas en señalización número 7, los nuevos servicios sobre Internet (voz sobre IP, ...

  18. Atmospheric tides and other relationships: ``Interpreting the Phenomena'' at the time of the Seeberg conference

    Science.gov (United States)

    Kokott, Wolfgang

    Lalande's account of his experiences at Gotha and on his journey back to France [AGE 2 (1798), 381-382] contains an interesting attempt to explain the extremely rainy September weather (``at a time of the year when it is raining more rarely in our countries'') by means of the Moon's southern declination. Actually, there are several other documents on the same subject; Lagrange was trying to prove his version of lunar influence against Lamarck who claimed exactly the opposite correlation to be true. In the light of Lalande's own work on oceanic tides, his interest in this meteorological problem is readily understood. While stringent limits for tidal variations of air pressure had already been established by d'Alembert (1747) and Toaldo (1779), no consistent theory of tidal mechanics was yet available. Theoretical and empirical investigations of alleged lunar influences on our weather did remain on the agenda well into the 19th century - the names of Olbers and Arago stand for many contemporaries. Moreover, the Earth's atmosphere was an object of fundamental interest to astronomers not only because of its influence on observational results, but also because it was the only accessible planetary atmosphere. Not only were sizeable gaseous envelopes of planetary bodies (with the apparent exception of only the Moon) considered as commonplace (Herschel, Schröter, etc.); the quest for understanding them was also an importent issue. As early as 1780, J.E. Bode tried (following Euler) to explain the blue colour of the sky by means of blue (scattering?) particles in the upper atmosphere; consequently, he raised the question of whether the red colour of Mars was due to this planet's surface materials or rather to a different atmospheric composition. In our time and age, a new and very successful branch of science called Comparative Planetology did emerge from apparently very modern roots; two centuries ago, its basic objectives were an undisputed part of everyday astronomical

  19. Improvement of ocean loading correction on gravity data with additional tide gauge measurements

    Science.gov (United States)

    Neumeyer, Juergen; del Pino, Jorge; Dierks, Olaf; Sun, He-Ping; Pflug, Hartmut

    2005-08-01

    Because a gravimeter records the sum of all gravity variations associated with mass redistribution in its near and far surrounding the investigation of a single special gravity effect (e.g. Earth tides or core modes) requires the reduction of all other effects from the data. In our study, we are dealing with the ocean loading effect. High-precision tidal gravity and atmospheric pressure observations are carried out at the station Rio Carpintero in combination with tide gauge measurements at the coast of Santiago de Cuba. The gravity data are subjected to atmospheric pressure and ocean loading corrections with different oceanic tidal models. In order to test the efficiency of the different ocean loading corrections the gravity data are analysed for various tidal waves and the determined Earth tide parameters are compared with model parameters. Additionally, tide gauge measurements are analysed and used for improving the ocean loading correction on gravity data. The results show that present-day global oceanic tidal models, e.g. NAO99b and FES2002 in combination with the ocean loading calculation program (LOAD97), are not sufficient for a complete correction of this effect. With our approach, the discrepancies between the observed Earth tide parameters and those from theoretical prediction for main waves in diurnal and semidiurnal tidal bands are further reduced when taking into account the tide gauge data recorded offshore. After additional removal of oceanic signals, based on the tide gauge data, the analysed Earth tide parameters are closer to the Wahr-Dehant model. The improvement is up to 4% and the noise is reduced from 20 nm/s 2 to 10 nm/s 2 within the examined period range of 10-1500 min. Therefore, high-precision gravity measurements (e.g. with Superconducting Gravimeters), especially for stations near the coastal lines, should take into account tide gauge measurements for the ocean loading correction. With improved ocean loading correction and reduced noise

  20. Numerical study of water age influenced by tide and runoff in Daliaohe Estuary in China

    Institute of Scientific and Technical Information of China (English)

    WANG Peng-cheng; ZHANG Xue-qing; ZHAO Qian; SHI Ming-zhu

    2013-01-01

    Based on the concept of the age,the water transport characteristics as the response to the runoff and the tide in Daliaohe Estuary in China are studied under different hydrodynamic conditions using a three-dimensional convection-diffusion model.The results show that the relationship between the average age at a specific position and the runoff could be expressed by a power function approximately.In the river channel,the runoff controls the water transport:it might take about 52 d,27 d and 15 d for the water parcel to be transported from Sanchahe to the mouth during the dry,normal and rainy seasons,respectively.Outside the mouth,the tide is dominant even though the difference between the spring tide and the neap tide is less than 5 d,and the water parcel transports mainly along the northwest direction through the West Waterway and the southeast direction through the East Waterway.A significant age stratification emerges in the vicinity of the mouth,in which there exists a strong interaction between the tide and the runoff,and the age differences between the surface and the bottom could reach 7 d.

  1. Development and Use of Tide Models in Alaska Supporting VDatum and Hydrographic Surveying

    Directory of Open Access Journals (Sweden)

    Lei Shi

    2014-03-01

    Full Text Available National Oceanic and Atmospheric Administration’s National Ocean Service uses observations, hydrodynamic models and interpolation techniques to develop many of its products and services. We examine how two projects, computation of tidal datums for vertical datum transformation and the estimation of tidal characteristics for hydrographic surveys, are being developed in Alaska and how they may be more seamlessly integrated. Preliminary VDatum development for Alaska is in progress for the Alaska Panhandle through the setup of a high resolution tide model that will be used to compute spatially varying tidal datums. Tide models such as these can be used for other projects that traditionally rely on estimation of tides in between data locations, such as the planning for hydrographic surveys that need correctors to adjust bathymetry to the chart datum. We therefore also examine how an existing model in western Alaska can be used for better supporting hydrographic survey planning. The results show that integration of tide models with nearshore observations can provide improved information for these correctors and future work will further evaluate this methodology with existing VDatum tide models.

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

    Science.gov (United States)

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

    2010-01-01

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

  3. Simultaneous generation and scattering of internal tides by ocean floor topography

    Science.gov (United States)

    Mathur, Manikandan

    2015-11-01

    Internal waves play a significant role in the global energy budget of the ocean, with internal tides potentially contributing to the conversion of a large amount of mechanical energy into heat in the deep ocean. Several studies in the past decade have investigated internal tide generation and internal tide scattering by ocean floor topography, but by treating them as two separate, independent processes. In this talk, we use the recently developed Green function model (Mathur et al., J. Geophys. Res. Oceans, 119, 2165-2182, 2014), sans the WKB approximation, to quantify the extent to which internal tide generation (scattering) that results from barotropic (baroclinic) forcing on small- and large-scale topography in uniform and nonuniform stratifications is modified by the presence of a background baroclinic (barotropic) tide. Results on idealized topography, stratification and forcing will first be presented, followed by a discussion on the relevance of our studies in the real ocean scenario. The author thanks the Ministry of Earth Sciences, Government of India for financial support under the Monsoon Mission Grant MM/2014/IND-002.

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

    Science.gov (United States)

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

    2014-08-01

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

  5. The change in mutagenicity:study on surface water of Qiantang River due to tide

    Institute of Scientific and Technical Information of China (English)

    WuNX; YangYM

    2002-01-01

    The Qiangtang River lies in Zhejiang Province of China.In this study,the genotoxicity of surface water samples from five sites along the river were detected using Ames test(TA98,TA100±S9),comet(SCGE) test and cytokinesis-block micronucleus(CBMN) tesdt(-S9) in the human peripheral lymphocytes in vitro.The results indicated that in upstream samples (first site) during falling-tide was found slight mutagenicity in TA98 strain with S9 and without S9.The mutagenicity of samples from the second to the fifth site was gradually stronger.Except the first site sample,the micronucleated cell rates of the other four samples during falling-tide significantly increased in CBMN test,and the extent of migration of DNA fragments of the four samples was found to be significantly different from control group.In the upstream(first site) samples during flow-tide were found no mutagen by three short-term tests.But the other four samples were found more stronger mutagenicity in TA98 strain with S9 than that during falling-tide.The micronucleated cell rates and the extent of migration of DNA fragments of the samples were sdignificantly high than that during falling-tide too.

  6. Seagrass responses to and recovery (?) from seven years of brown tide

    Science.gov (United States)

    Onuf, C.P.

    2000-01-01

    Most harmful algal blooms are relatively short, violent paroxysms to aquatic systems. The Texas brown tide was unique in its 7-year domination of upper Laguna Madre wherein it reduced light penetrating 1 m from 31 to 63% on an annual basis between June 1990 and May 1997. In response, seagrasses declined in biomass in deep areas for two years. Over the next three years, bare areas opened up in the deepest areas of the seagrass meadow and the outer seagrass boundary retreated landward. In the last two years of the brown tide, regression of the dominant species, Halodule wrightii, slowed and stopped, and Halophila engelmanni, a previously minor species, revegetated some areas. Subsequent to cessation of meadow retreat, water clarity improved to pre-brown tide levels, consistent with the hypothesis that regeneration of nutrients from retreating seagrass meadow may have been the source of the nutrient subsidy required to sustain the brown tide at high concentration. However, after a short interlude of clear water and Halodule recovery, a resurgence of the bloom occurred and areas of regrowth succumbed. Although human activities did not seem to be involved in initiation or persistence of the brown tide, nutrients brought in by runoff from agricultural lands may have contributed to the return of bloom conditions.

  7. A Global Map of Coherent M2 Internal Tide Surface Elevations

    Science.gov (United States)

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

    2014-12-01

    Satellite altimetry reveals small surface waves, with elevations of order 1 cm or smaller, associated with internal tides in the deep ocean. The global satellite data provide an unprecedented picture of such waves, potentially yielding much information about the ocean interior. Accurate knowledge of these waves is also needed for de-tiding altimetry in certain sensitive applications, including the future SWOT mission. Several approaches have been initiated recently to map these tiny waves, usually with some reliance on hydrographic information (e.g., recent work by Dushaw et al., 2011). Here we explore the feasibility of a purely empirical approach which avoids assumptions about stratification or modal wavelengths. A global elevation map is constructed based on tidal analysis of Topex/Poseidon, Jason, ERS-2, Envisat and GFO data. Small (order 5 mm) residuals, with wavelengths much longer than the baroclinic tide, appear unless now-standard along-track high-pass filters are applied, but filtering is shown to cause serious loss of information for east-west propagating waves (given typical track patterns). The technique is probably infeasible for S2 because of Envisat's and ERS's sun-synchronous orbits. Independent data from Cryosat-2 is used to validate the results. Applying our internal-tide 'correction' to Cryosat-2 data confirms a small reduction in variance in expected locations of significant internal tides.

  8. Automatic Extraction of Tide-Coordinated Shoreline Using Open Source Software and Landsat Imagery

    Science.gov (United States)

    Goncalves, G.; Duro, N.; Sousa, E.; Figueiredo, I.

    2015-04-01

    Due to both natural and anthropogenic causes, the coastal lines keeps changing dynamically and continuously their shape, position and extend over time. In this paper we propose an approach to derive a tide-coordinate shoreline from two extracted instantaneous shorelines corresponding to a nearly low tide and high tide events. First, all the multispectral images are panshaperned to meet the 15 meters spatial resolution of the panchromatic images. Second, by using the Modification of Normalized Difference Water Index (MNDWI) and the kmeans clustering method we extract the raster shoreline for each image acquisition time. Third, each raster shoreline is smoothed and vectorized using a penalized least square method. Fourth, a 2D constrained Delaunay triangulation is built from the two extracted instantaneous shorelines with their respective heights interpolated from a Tidal gauche station. Finally, the desired tide-coordinate shoreline is interpolated from the previous triangular intertidal surface. The results show that an automatic tide-coordinated extraction method can be efficiently implemented using free available remote sensing imagery data (Landsat 8) and open source software (QGIS and Orfeo toolbox) and python scripting for task automation and software integration.

  9. Graphical aerosol classification method using aerosol relative optical depth

    Science.gov (United States)

    Chen, Qi-Xiang; Yuan, Yuan; Shuai, Yong; Tan, He-Ping

    2016-06-01

    A simple graphical method is presented to classify aerosol types based on a combination of aerosol optical thickness (AOT) and aerosol relative optical thickness (AROT). Six aerosol types, including maritime (MA), desert dust (DD), continental (CO), sub-continental (SC), urban industry (UI) and biomass burning (BB), are discriminated in a two dimensional space of AOT440 and AROT1020/440. Numerical calculations are performed using MIE theory based on a multi log-normal particle size distribution, and the AROT ranges for each aerosol type are determined. More than 5 years of daily observations from 8 representative aerosol sites are applied to the method to confirm spatial applicability. Finally, 3 individual cases are analyzed according to their specific aerosol status. The outcomes indicate that the new graphical method coordinates well with regional characteristics and is also able to distinguish aerosol variations in individual situations. This technique demonstrates a novel way to estimate different aerosol types and provide information on radiative forcing calculations and satellite data corrections.

  10. Susceptibility of tropical shellfishes from paralytic shellfish poisoning toxins during toxic red tide occurrences in the Philippines

    International Nuclear Information System (INIS)

    Paralytic shellfish poisoning or PSP caused by dinoflagellates containing toxins is the most prominent among shellfish poisoning because of its wold wide occurrence, severe symptoms and high fatal outcomes. It was increasingly observed in the tropical regions over the past decades and has resulted in huge economical decline and serious threat to human safety. In the Philippines, toxic blooms of Pyrodinium bahamense var. compressum (Pbc) have been addressed by the Philippine government by instituting national monitoring program and decentralizing the said activity to the regional level for immediate dissemination of results. Also, part of the program is to impose total ban on all kinds of shellfishes to protect consumer's health. However, this management strategy experiences alarming concerns and criticisms due to limited information to support such regulation policy. Under this prevailing condition, research interventions to mitigate impacts of PSP were carried out. Various species of shellfishes from different habitat were collected during harmful algal bloom episodes in Sorsogon Bay, Philippines and were subjected to PSP toxin analysis using HPLC. Results revealed that there is a notable distinction on shellfish toxicities from different habitat. Efifaunal species including green mussel Perna viridis which is the indicator shellfish for PSP monitoring in the Philippines, exhibited high toxicity levels while benthic species also showed high toxicity values but in a lesser extent suggesting that shellfishes from these environments are susceptible to PSP toxin contamination. On the contrary, infaunal species showed nil toxicities except for a commercially important bivalve Carpet shell Paphia undulata that showed minimal contamination of 55,000 cells/1 of Pbc quite the opposite with the obtained toxicity values from P. viridis. A similar trend was obtained when these two bivalves were exposed directly to Pbc under a suitable laboratory replicated natural habitat. Based from the results, it can be implied that the infaunal nature of P. undulata accounts for almost non accumulation of PSP toxins and hence, it is safe for human consumption even during peak of toxic bloom. On the other hand, bioaccumulation and distribution of PSP toxins were analyzed in different tissues of another commercially important large benthic bivalve, Penshell atrina pectinata. Remarkably, adductor muscle of A. pectinata accumulates minimal level of psp toxins in contrast with the results obtained from P. viridis which served as the control. Standard mouse bioassay regularly used in PSP monitoring in the Philippines was also performed and revealed that the abductor muscle of A. pectinata had non-detectable level of toxins. From these findings, removal of the latter part from the whole body A. pectinata for marketable purposes also suggests safe human consumption inspite of harmful algal bloom occurrences. (author)

  11. [Algicidal activity against red-tide algaes by marine bacterial strain N3 isolated from a HABs area, southern China].

    Science.gov (United States)

    Shi, Rong-jun; Huang, Hong-hui; Qi, Zhan-hui; Hu, Wei-an; Tian, Zi-yang; Dai, Ming

    2013-05-01

    A marine algicidal bacterium N3 was isolated from a HABs area in Mirs Bay, a subtropical bay, in southern China. Algicidal activity and algicidal mode against Phaeodactylum tricornutum, Scrippsiella trochoidea, Prorocentrum micans and Skeletonema costatum were observed by the liquid infection method. The results showed that there were no algicidal activities against P. tricornutum and S. costatum. However, when the bacterial volume fractions were 2% and 10% , S. trochoidea and P. micans could be killed, respectively. S. trochoidea cells which were exposed to strain N3 became irregular in shape and the cellular components lost their integrity and were decomposed. While, the P. micans cells became inflated and the cellular components aggregated, followed by cell lysis. Strain N3 killed S. trochoidea and P. micans directly, and the algicidal activities of the bacterial strain N3 was concentration-dependent. To S. trochoidea, 2% (V/V) of bacteria in algae showed the strongest algicidal activity, all of the S. trochoidea cells were killed within 120 h. But the growth rates of cells, in the 1% and 0. 1% treatment groups, were only slightly lower than that in the control group. In all treatment groups, the densities of strain N3 were in declining trends. While, to P. micans, 10% and 5% of bacteria in algae showed strong algicidal activities, 78% and 70% of the S. trochoidea were killed within 120 h, respectively. However, the number of S. trochoidea after exposure to 1% of bacterial cultures still increased up to 5 incubation days. And in the three treatment groups, the densities of strain N3 experienced a decrease process. The isolated strain N3 was identified as Bacillus sp. by morphological observation, physiological and biochemical characterization, and homology comparisons based on 16S rRNA sequences. PMID:23914549

  12. USING CLAY TO CONTROL RED TIDES: I. FLOCCULATION, SEDIMENTATION, AND RESUSPENSION OF CLAY/ALGAL FLOCS. (R827090)

    Science.gov (United States)

    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...

  13. Willingness-to-Pay for Red Tide Prevention, Mitigation, and Control Strategies: A Case Study of Florida Coastal Residents

    OpenAIRE

    Lucas, Kristen M.; Larkin, Sherry L.; Adams, Charles M.

    2010-01-01

    Harmful algal blooms (HABS) are natural events with ecological and economic consequences worldwide. Different nations and regions have adapted to HABS in a variety of ways including distinct strategies designed to prevent, control and or mitigate the negative effects of HAB events. In Florida, Karenia brevis is the algae species that has accounted for nearly all of blooms. This algae species is unique in that the toxins produced during the bloom are a neurotoxin that can kill fish and marine ...

  14. Red tides of the dinoflagellate Noctiluca scintillans associated with eutrophication in the Sea of Marmara (the Dardanelles, Turkey)

    OpenAIRE

    Muhammet Turkoglu

    2013-01-01

    This investigation focused on weekly variations in cell density and volume of the dinoflagellateNoctiluca scintillans between March 2001 and January 2004 in the Dardanelles. March-June andOctober-December periods were excessive bloom periods. During the bloomperiods the density of N. scintillans reached 2.20 × 105 cells L-1 witha volume of 1.32 × 1012 µm3 L-1. In addition tothe high surface density, there was an increase in subsurface waters duringthe blooms. The bloom of N. scint...

  15. Growth Characteristics of Heterosigma akashiwo Virus and Its Possible Use as a Microbiological Agent for Red Tide Control

    OpenAIRE

    Nagasaki, Keizo; Tarutani, Kenji; Yamaguchi, Mineo

    1999-01-01

    The growth characteristics of Heterosigma akashiwo virus clone 01 (HaV01) were examined by performing a one-step growth experiment. The virus had a latent period of 30 to 33 h and a burst size of 7.7 × 102 lysis-causing units in an infected cell. Transmission electron microscopy showed that the virus particles formed on the peripheries of viroplasms, as observed in a natural H. akashiwo cell. Inoculation of HaV01 into a mixed algal culture containing four phytoplankton species, H. akashiwo H9...

  16. Red tides of the dinoflagellate Noctiluca scintillans associated with eutrophication in the Sea of Marmara (the Dardanelles, Turkey

    Directory of Open Access Journals (Sweden)

    Muhammet Turkoglu

    2013-08-01

    Full Text Available This investigation focused on weekly variations in cell density and volume of the dinoflagellateNoctiluca scintillans between March 2001 and January 2004 in the Dardanelles. March-June andOctober-December periods were excessive bloom periods. During the bloomperiods the density of N. scintillans reached 2.20 × 105 cells L-1 witha volume of 1.32 × 1012 µm3 L-1. In addition tothe high surface density, there was an increase in subsurface waters duringthe blooms. The bloom of N. scintillans, like that of diatom and otherdinoflagellate blooms, was associated not only with eutrophication, but alsowith stable temperatures and salinities.

  17. Myrionecta Rubra Population Genetic Diversity and Its Cryptophyte Chloroplast Specificity in Recurrent Red Tides in the Columbia River Estuary

    Energy Technology Data Exchange (ETDEWEB)

    Herfort, Lydie; Peterson, Tawnya D.; McCue, Lee Ann; Crump, Byron C.; Prahl, Fredrick G.; Baptista, Antonio M.; Campbell, Victoria; Warnick, Rachel; Selby, Mikaela; Roegner, G. Curtis; Zuber, Peter A.

    2011-01-04

    For at least a decade, annually recurring blooms of the photosynthetic ciliate, Myrionecta rubra have been observed in the Columbia River estuary in late summer. In an effort to understand the dynamics of these blooms, we investigated the genetic variability of M. rubra and its cryptophyte plastids within three large estuarine blooms formed in consecutive years (2007-2009), and conducted a broader spatial survey along the coasts of Oregon/Washington. Analysis of the ‘18S-28S’ sequences specific for Mesodiniidae uncovered at least 7 variants of M. rubra within the Columbia River coastal margin in spring and summer, but only one of these M. rubra variants was implicated in estuary bloom formation. Using a multigene approach, we show that the bloom-forming variant of M. rubra appears to harbor the same cryptophyte chloroplast in recurring blooms. Analyses of chloroplast 16S rRNA, cryptophyte RuBisCO and Photosystem II D2 genes together suggest that the plastid is derived from Teleaulax amphioxeia. Free-living cells of this species and of other cryptophytes were practically absent from the bloom patches in the estuary main channels based on 18S rDNA sequence analyses. The respectively low and high proportions of T. amphioxeia nuclei and chloroplasts signals found in the M. rubra bloom of the Columbia River estuary in successive years supports the notion of a transient association between T. amphioxeia and the bloom-forming M. rubra variant, with loss of cryptophyte nuclei. The genetic variability of M. rubra uncovered here is relevant to the controversy in the literature regarding the cryptophyte /M. rubra association.

  18. Aerosolized avian influenza virus by laboratory manipulations

    Directory of Open Access Journals (Sweden)

    Li Zhiping

    2012-08-01

    Full Text Available Abstract Background Avian H5N1 influenza viruses present a challenge in the laboratory environment, as they are difficult to collect from the air due to their small size and relatively low concentration. In an effort to generate effective methods of H5N1 air removal and ensure the safety of laboratory personnel, this study was designed to investigate the characteristics of aerosolized H5N1 produced by laboratory manipulations during research studies. Results Normal laboratory procedures used to process the influenza virus were carried out independently and the amount of virus polluting the on-site atmosphere was measured. In particular, zootomy, grinding, centrifugation, pipetting, magnetic stirring, egg inoculation, and experimental zoogenetic infection were performed. In addition, common accidents associated with each process were simulated, including breaking glass containers, syringe injection of influenza virus solution, and rupturing of centrifuge tubes. A micro-cluster sampling ambient air pollution collection device was used to collect air samples. The collected viruses were tested for activity by measuring their ability to induce hemagglutination with chicken red blood cells and to propagate in chicken embryos after direct inoculation, the latter being detected by reverse-transcription PCR and HA test. The results showed that the air samples from the normal centrifugal group and the negative-control group were negative, while all other groups were positive for H5N1. Conclusions Our findings suggest that there are numerous sources of aerosols in laboratory operations involving H5N1. Thus, laboratory personnel should be aware of the exposure risk that accompanies routine procedures involved in H5N1 processing and take proactive measures to prevent accidental infection and decrease the risk of virus aerosol leakage beyond the laboratory.

  19. Aerosol samplers innovation possibilities

    International Nuclear Information System (INIS)

    The growing demand for an early detection of increased levels of the artificial radionuclides in the atmosphere resulted in the design and fabrication of an aerosol sampler with automated spectrometric unit providing online gamma spectrometry above the aerosol filter. Study was performed with two types of high volume samplers- SENYA JL-900 SnowWhite (900 m3/h) a SENYA JL-150 Hunter (150 m3/h). This work gives results of the design optimization with respect to the detector type, geometry of measurement, remote control and spectrometric evaluation 222Rn and 220Rn concentration fluctuations in the outdoor air are discussed with regard to the detection limit so the radionuclides expected after the NPP accident. (authors)

  20. An aerosol sampler

    International Nuclear Information System (INIS)

    That device is characterized in that, within a closed casing provided with a sealable opening, it comprises a storage rack for a plurality of stacked saucers, a sheath having a transverse slot for extracting said saucers separately from, or re-introducing same into, their respective sockets, a transfer gripping-member with its control mechanism for taking saucers from their respective sockets through said slot and moving them transversally, a sealing-plate mounted below the casing-opening, said plate being associated with a pushing mechanism, and a laterally retractable cover controlled by a separate mechanism for unsealing said casing opening and collecting aerosols on a saucer. That device can be used for taking samples of sodium aerosols

  1. Experimental information: 225 [RED

    Lifescience Database Archive (English)

    Full Text Available 2202_21_1_2 RED Cy3 Cy3 Masaaki Umeda The University of Tokyo Cell ... cycle Transgenic Cell ... cycle T ... ransgenic cell ... division,cell ... cycle,cyclin,CDK,transgenic plant on ...

  2. Experimental information: 226 [RED

    Lifescience Database Archive (English)

    Full Text Available 2202_21_1_3 RED Cy3 Cy3 Masaaki Umeda The University of Tokyo Cell ... cycle Transgenic Cell ... cycle T ... ransgenic cell ... division,cell ... cycle,cyclin,CDK,transgenic plant on ...

  3. Probe data: 2827 [RED

    Lifescience Database Archive (English)

    Full Text Available R06-035040-2AR RED C72992 AU101214 E02619 EB2619 >(P35339) EXOPOLYGALACTURONASE PRECURSOR (EC 3. ... 2.1.67) (EXOPG) (PECTINASE ) (GALACTURAN 1,4-ALPHA-GALACTURONIDASE). &S30067(S ...

  4. Probe data: 6229 [RED

    Lifescience Database Archive (English)

    Full Text Available R03-061580-1AR RED AU108708 C96917 C50119 CG0119 >(P52424) PHOSPHORIBOSYLFORMYLGLYCINAMIDINE CYC ... LO-LIGASE PRECURSOR (EC 6.3.3.1) (AIR S) (PHOSPHORIBOSYL-AMINOIMIDAZOLE SYNTHETASE) (AIR ...

  5. Experimental information: 1043 [RED

    Lifescience Database Archive (English)

    Full Text Available 2112_21_11_12 RED Cy3 Cy5 Toru Fujiwara Agricultural and Life Sciences, The University of Tokyo ... Nutrient Metabolism Nutrient Metabolism sulfur nutrition ,root,O-acetyl-L-serine,gluthatione,time course two ...

  6. Experimental information: 1038 [RED

    Lifescience Database Archive (English)

    Full Text Available 2112_21_1_2 RED Cy3 Cy5 Toru Fujiwara Agricultural and Life Sciences, The University of Tokyo Nu ... trient Metabolism Nutrient Metabolism sulfur nutrition ,root,O-acetyl-L-serine,gluthatione,time course two ...

  7. Experimental information: 1040 [RED

    Lifescience Database Archive (English)

    Full Text Available 2112_21_5_6 RED Cy3 Cy5 Toru Fujiwara Agricultural and Life Sciences, The University of Tokyo Nu ... trient Metabolism Nutrient Metabolism sulfur nutrition ,root,O-acetyl-L-serine,gluthatione,time course two ...

  8. Experimental information: 1042 [RED

    Lifescience Database Archive (English)

    Full Text Available 2112_21_9_10 RED Cy3 Cy5 Toru Fujiwara Agricultural and Life Sciences, The University of Tokyo N ... utrient Metabolism Nutrient Metabolism sulfur nutrition ,root,O-acetyl-L-serine,gluthatione,time course two ...

  9. Experimental information: 1039 [RED

    Lifescience Database Archive (English)

    Full Text Available 2112_21_3_4 RED Cy3 Cy5 Toru Fujiwara Agricultural and Life Sciences, The University of Tokyo Nu ... trient Metabolism Nutrient Metabolism sulfur nutrition ,root,O-acetyl-L-serine,gluthatione,time course two ...

  10. Experimental information: 1041 [RED

    Lifescience Database Archive (English)

    Full Text Available 2112_21_7_8 RED Cy3 Cy5 Toru Fujiwara Agricultural and Life Sciences, The University of Tokyo Nu ... trient Metabolism Nutrient Metabolism sulfur nutrition ,root,O-acetyl-L-serine,gluthatione,time course two ...

  11. Aerosol Observing System (AOS) Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Jefferson, A

    2011-01-17

    The Aerosol Observing System (AOS) is a suite of in situ surface measurements of aerosol optical and cloud-forming properties. The instruments measure aerosol properties that influence the earth’s radiative balance. The primary optical measurements are those of the aerosol scattering and absorption coefficients as a function of particle size and radiation wavelength and cloud condensation nuclei (CCN) measurements as a function of percent supersaturation. Additional measurements include those of the particle number concentration and scattering hygroscopic growth. Aerosol optical measurements are useful for calculating parameters used in radiative forcing calculations such as the aerosol single-scattering albedo, asymmetry parameter, mass scattering efficiency, and hygroscopic growth. CCN measurements are important in cloud microphysical models to predict droplet formation.

  12. Aerosol characterization during project POLINAT

    Energy Technology Data Exchange (ETDEWEB)

    Hagen, D.E.; Hopkins, A.R.; Paladino, J.D.; Whitefield, P.D. [Missouri Univ., Rolla, MO (United States). Cloud and Aerosol Sciences Lab.; Lilenfeld, H.V. [McDonnell Douglas Aerospace-East, St. Louis, MO (United States)

    1997-12-31

    The objectives of the aerosol/particulate characterization measurements of project POLINAT (POLlution from aircraft emissions In the North ATlantic flight corridor) are: to search for aerosol/particulate signatures of air traffic emissions in the region of the North Atlantic Flight Corridor; to search for the aerosol/particulate component of large scale enhancement (`corridor effects`) of air traffic related species in the North Atlantic region; to determine the effective emission indices for the aerosol/particulate component of engine exhaust in both the near and far field of aircraft exhaust plumes; to measure the dispersion and transformation of the aerosol/particulate component of aircraft emissions as a function of ambient condition; to characterize background levels of aerosol/particulate concentrations in the North Atlantic Region; and to determine effective emission indices for engine exhaust particulates for regimes beyond the jet phase of plume expansion. (author) 10 refs.

  13. Dust and atmospheric aerosol

    International Nuclear Information System (INIS)

    The paper describes the types and characteristics of the various aerosol particles (by size effects, and origin) and goes on to discuss the composition of particulates and their variation in different places in Asia, and the origin of global particulate emissions from natural and anthropogenic sources. The effects of particulate matter on human health, visibility and climate are summarised. Techniques for control and abatement of particulate emissions are outlined. 10 refs., 4 figs., 11 tabs

  14. Probe data: 3426 [RED

    Lifescience Database Archive (English)

    Full Text Available R02-002330-1AR RED C26646 AU108627 C12762 CB2762 >AGU83687_1(U83687|pid:g1835701) Apium graveole ... ns NADPH-dependent mannose 6-phosphate ... reductase (m6pr) mRNA, complete cds; aldo-keto red ... uctase; similar to aldose 6-phosphate ... reductase also known as NADP-sorbitol-6-phosphate ...

  15. Probe data: 779 [RED

    Lifescience Database Archive (English)

    Full Text Available R02-002330-1AR RED D48175 AU032804 S14252 SS4252 >AGU83687_1(U83687|pid:g1835701) Apium graveole ... ns NADPH-dependent mannose 6-phosphate ... reductase (m6pr) mRNA, complete cds; aldo-keto red ... uctase; similar to aldose 6-phosphate ... reductase also known as NADP-sorbitol-6-phosphate ...

  16. Probe data: 3773 [RED

    Lifescience Database Archive (English)

    Full Text Available R02-002330-1AR RED AU163183 AU163184 S00625 ST0625 >AGU83687_1(U83687|pid:g1835701) Apium graveo ... lens NADPH-dependent mannose 6-phosphate ... reductase (m6pr) mRNA, complete cds; aldo-keto red ... uctase; similar to aldose 6-phosphate ... reductase also known as NADP-sorbitol-6-phosphate ...

  17. Mechanical Extraction of Power From Ocean Currents and Tides

    Science.gov (United States)

    Jones, Jack; Chao, Yi

    2010-01-01

    A proposed scheme for generating electric power from rivers and from ocean currents, tides, and waves is intended to offer economic and environmental advantages over prior such schemes, some of which are at various stages of implementation, others of which have not yet advanced beyond the concept stage. This scheme would be less environmentally objectionable than are prior schemes that involve the use of dams to block rivers and tidal flows. This scheme would also not entail the high maintenance costs of other proposed schemes that call for submerged electric generators and cables, which would be subject to degradation by marine growth and corrosion. A basic power-generation system according to the scheme now proposed would not include any submerged electrical equipment. The submerged portion of the system would include an all-mechanical turbine/pump unit that would superficially resemble a large land-based wind turbine (see figure). The turbine axis would turn slowly as it captured energy from the local river flow, ocean current, tidal flow, or flow from an ocean-wave device. The turbine axis would drive a pump through a gearbox to generate an enclosed flow of water, hydraulic fluid, or other suitable fluid at a relatively high pressure [typically approx.500 psi (approx.3.4 MPa)]. The pressurized fluid could be piped to an onshore or offshore facility, above the ocean surface, where it would be used to drive a turbine that, in turn, would drive an electric generator. The fluid could be recirculated between the submerged unit and the power-generation facility in a closed flow system; alternatively, if the fluid were seawater, it could be taken in from the ocean at the submerged turbine/pump unit and discharged back into the ocean from the power-generation facility. Another alternative would be to use the pressurized flow to charge an elevated reservoir or other pumped-storage facility, from whence fluid could later be released to drive a turbine/generator unit at a

  18. Tide-driven fluid mud transport in the Ems estuary

    Science.gov (United States)

    Becker, Marius; Maushake, Christian; Winter, Christian

    2014-05-01

    The Ems estuary, located at the border between The Netherlands and Germany, experienced a significant change of the hydrodynamic regime during the past decades, as a result of extensive river engineering. With the net sediment transport now being flood-oriented, suspended sediment concentrations have increased dramatically, inducing siltation and formation of fluid mud layers, which, in turn, influence hydraulic flow properties, such as turbulence and the apparent bed roughness. Here, the process-based understanding of fluid mud is essential to model and predict mud accumulation, not only regarding the anthropogenic impact, but also in view of the expected changes of environmental boundary conditions, i.e., sea level rise. In the recent past, substantial progress has been made concerning the understanding of estuarine circulation and influence of tidal asymmetry on upstream sediment accumulation. While associated sediment transport formulations have been implemented in the framework of numerical modelling systems, in-situ data of fluid mud are scarce. This study presents results on tide-driven fluid mud dynamics, measured during four tidal cycles aside the navigation channel in the Ems estuary. Lutoclines, i.e., strong vertical density gradients, were detected by sediment echo sounder (SES). Acoustic Doppler current profiles (ADCP) of different acoustic frequencies were used to determine hydrodynamic parameters and the vertical distribution of suspended sediment concentrations in the upper part of the water column. These continuous profiling measurements were complemented by CTD, ADV, and OBS casts. SES and ADCP profiles show cycles of fluid mud entrainment during accelerating flow, and subsequent settling, and the reformation of a lutocline during decelerating flow and slack water. Significant differences are revealed between flood and ebb phase. Highest entrainment rates are measured at the beginning of the flood phase, associated with strong current shear and

  19. Photothermal spectroscopy of aerosols

    International Nuclear Information System (INIS)

    In situ aerosol absorption spectroscopy was performed using two novel photothermal detection schemes. The first, based on a photorefractive effect and coherent detection, called phase fluctuation optical heterodyne (PFLOH) spectroscopy, could, depending on the geometry employed, yield particle specific or particle and gas absorption data. Single particles of graphite as small as 1 μm were detected in the particle specific mode. In another geometrical configuration, the total absorption (both gas and particle) of submicron sized aerosols of ammonium sulfate particles in equilibrium with gaseous ammonia and water vapor were measured at varying CO2 laser frequencies. The specific absorption coefficient for the sulfate ion was measured to be 0.5 m2/g at 1087 cm-1. The absorption coefficient sensitivity of this scheme was less than or equal to 10-8 cm-1. The second scheme is a hybrid visible Mie scattering scheme incorporating photothermal modulation. Particle specific data on ammonium sulfate droplets were obtained. For chemically identical species, the relative absorption spectrum versus laser frequency can be obtained for polydisperse aerosol distributions directly from the data without the need for complex inverse scattering calculations

  20. Aerosol distribution and efficacy in a commercial food warehouse

    Institute of Scientific and Technical Information of China (English)

    Frank H. Arthur

    2008-01-01

    A series of field trials were conducted in a commercial food storage facility to evaluate exposure of stored-product insects to aerosol formulations of synergized pyrethrins and the insect growth regulator methoprene. When adults of Tribolium castaneum (Herbst), the red flour beetle, and Tribolium confusum (Jacqueline DuVal), the confused flour beetle were exposed with and without a food source to synergized pyrethrin aerosol, there was no difference in adult mortality with respect to availability of food at either 7 or 14 days after exposure (P≥0.05). However, mortality was lower in T. confusum (40.4% and 79.3% with flour at 7 and 14 days, 38.9% and 84.8% without flour at 7 and 14 days) compared to T. castaneum (96.5% and 99.8% with flour at 7 and 14 days, 91.0% and 98.7% without flour at 7 and 14 days). Few late-stage larvae and pupae of either species exposed to the pyrethrin aerosol emerged as adults. In tests with methoprene aerosol, adult emergence of exposed 3- and 4-week-old larvae of T. confusum was less than 2%. Only 0.3% of 4-week-old larvae of T. castaneum exposed in open and obstructed areas emerged as adults. Emergence of adults from eggs of Plodia interpunctella (Huibner), the Indianmeal moth, embedded in culture media and exposed to the methoprene aerosol was 13.2% + 3.5%. Results show that the aerosols evaluated in our study could give effective control of some of the major storedproduct insect pests in commercial food storage facilities, and may offer an alternative to fumigation.