9 resultados para surface time

em Aquatic Commons


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Daily sea surface temperatures have been acquired at the Hopkins Marine Station in Pacific Grove, California since January 20, 1919.This time series is one of the longest oceanographic records along the U.S. west coast. Because of its length it is well-suited for studying climate-related and oceanic variability on interannual, decadal, and interdecadal time scales. The record, however, is not homogeneous, has numerous gaps, contains possible outliers, and the observations were not always collected at the same time each day. Because of these problems we have undertaken the task of reconstructing this long and unique series. We describe the steps that were taken and the methods that were used in this reconstruction. Although the methods employed are basic, we believe that they are consistent with the quality of the data. The reconstructed record has values at every time point, original, or estimated, and has been adjusted for time-of-day variations where this information was available. Possible outliers have also been examined and replaced where their credibility could not be established. Many of the studies that have employed the Hopkins time series have not discussed the issue of data quality and how these problems were addressed. Because of growing interest in this record, it is important that a single, well-documented version be adopted, so that the results of future analyses can be directly compared. Although additional work may be done to further improve the quality of this record, it is now available via the internet. [PDF contains 48 pages]

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Report seeks to address following questions: 1. Where within Lee County are surface supplies of water located? 2. What are the variations in this supply? 3. What can be done to provide better answers to questions 1 and 2 than are available at the present time? (PDF contains 76 pages.)

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The Alliance for Coastal Technologies (ACT) held a Workshop on Sensor Technology for Assessing Groundwater-Surface Water Interactions in the Coastal Zone on March 7 to 9,2005 in Savannah, GA. The main goal of the workshop was to summarize the general parameters, which have been found to be useful in assessing groundwater-surface water (GW-SW) interactions in the coastal zone. The workshop participants (Appendix I) were specifically charged with identifying the types of sensor systems, if any, that have been used to obtain time-series data and to make known which parameters may be the most amenable to the development/application of sensor technology. The group consisted of researchers, industry representatives, and environmental managers. Four general recommendations were made: 1. Educate coastal managers and agencies on the importance of GW-SW interactions, keeping in mind that regulatory agencies are driven by a different set of rules than researchers: the focus is on understanding the significance of the problem and providing solutions. ACT could facilitate this process in two ways. First, given that the research literature on this subject is fairly diffuse, ACT could provide links from its web site to fact sheets or other literature. Second, ACT could organize a focused meeting for managers and/or agency groups. Encourage development of primary tools for quantifying flow. The most promising technology in this respect is flow meters designed for flux chambers, mainly because they should be simple to use and can be made relatively inexpensively. However, it should be kept in mind that they provide only point measurements and several would need to be deployed as a network in order to obtain reliable flow estimates. For evaluating system wide GW-SW interactions, tools that integrate the signal over large areas would be required. Suggestions include a user-friendly hydrogeologic models, keeping in mind that freshwater flow is not the entire story, or continuous radon monitors. Though the latter would be slightly more difficult to use in terms of background knowledge, such an instrument would be low power and easy to operate and maintain. ACT could facilitate this recommendation by identifying funding opportunities on its web site and/or performing evaluations of existing technologies that could be summarized on the web site. (pdf contains 18 pages)

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Technological progress, having reached in our time an unprecedented speed, is still increasing the rate of mineral extraction, industrial construction, and the mastering of new kinds of energy is growing. Correspondingly the anthropogenic load on the biosphere is increased and that requires the comprehensive development of monitoring the anthropogenic changes in the natural environment. Among problems resulting from the scientific-technological development, a noticeable place is given to the problem of pure water. Surface land waters proved to be a sensitive link in the natural environment. The hydrobiological service for observations and control of the surface waters is one of the subsystems of the State/Federal Service for Observations and Control of pollution levels in environmental objects, conducted by the USSR State Committee for Hydrometeor- ology and Control of the Natural Environment. This paper summarises the the main principles of the organisation and goals of the national system of monitoring of the state of the natural environment in the USSR.

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Data recovered from 11 popup satellite archival tags and 3 surgically implanted archival tags were used to analyze the movement patterns of juvenile northern bluefin tuna (Thunnus thynnus orientalis) in the eastern Pacific. The light sensors on archival and pop-up satellite transmitting archival tags (PSATs) provide data on the time of sunrise and sunset, allowing the calculation of an approximate geographic position of the animal. Light-based estimates of longitude are relatively robust but latitude estimates are prone to large degrees of error, particularly near the times of the equinoxes and when the tag is at low latitudes. Estimating latitude remains a problem for researchers using light-based geolocation algorithms and it has been suggested that sea surface temperature data from satellites may be a useful tool for refining latitude estimates. Tag data from bluefin tuna were subjected to a newly developed algorithm, called “PSAT Tracker,” which automatically matches sea surface temperature data from the tags with sea surface temperatures recorded by satellites. The results of this algorithm compared favorably to the estimates of latitude calculated with the lightbased algorithms and allowed for estimation of fish positions during times of the year when the lightbased algorithms failed. Three near one-year tracks produced by PSAT tracker showed that the fish range from the California−Oregon border to southern Baja California, Mexico, and that the majority of time is spent off the coast of central Baja Mexico. A seasonal movement pattern was evident; the fish spend winter and spring off central Baja California, and summer through fall is spent moving northward to Oregon and returning to Baja California.

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We present a method to integrate environmental time series into stock assessment models and to test the significance of correlations between population processes and the environmental time series. Parameters that relate the environmental time series to population processes are included in the stock assessment model, and likelihood ratio tests are used to determine if the parameters improve the fit to the data significantly. Two approaches are considered to integrate the environmental relationship. In the environmental model, the population dynamics process (e.g. recruitment) is proportional to the environmental variable, whereas in the environmental model with process error it is proportional to the environmental variable, but the model allows an additional temporal variation (process error) constrained by a log-normal distribution. The methods are tested by using simulation analysis and compared to the traditional method of correlating model estimates with environmental variables outside the estimation procedure. In the traditional method, the estimates of recruitment were provided by a model that allowed the recruitment only to have a temporal variation constrained by a log-normal distribution. We illustrate the methods by applying them to test the statistical significance of the correlation between sea-surface temperature (SST) and recruitment to the snapper (Pagrus auratus) stock in the Hauraki Gulf–Bay of Plenty, New Zealand. Simulation analyses indicated that the integrated approach with additional process error is superior to the traditional method of correlating model estimates with environmental variables outside the estimation procedure. The results suggest that, for the snapper stock, recruitment is positively correlated with SST at the time of spawning.

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EXTRACT (SEE PDF FOR FULL ABSTRACT): Several snow accumulation time series derived from ice cores and extending over 3 to 5 centuries are examined for spatial and temporal climatic information. ... A significant observation is the widespread depression of net snow accumulation during the latter part of the "Little Ice Age". This initially suggests sea surface temperatures were significantly depressed during the same period. However, prior to this, the available core records indicate generally higher than average precipitation rates. This also implies that influences such as shifted storm tracks or a dustier atmosphere may have been involved. Without additional spatial data coverage, these observations should properly be studied using a coupled (global) ocean/atmosphere GCM.

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EXTRACT (SEE PDF FOR FULL ABSTRACT): Recently, paleoceanographers have been challenged to produce reliable proxies of climate variables that can be incorporated into climate models. In developing proxies using time series of annual radiolarian species fluxes from Santa Barbara Basin, we identify groups of species associated with years of extreme sea surface temperatures and sea level heights.

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Seasonal sampling from 40 immature Caspian salmon were performed in summer, autumn, winter and spring. The maximum ranges of RBC counts, Hct, Hb, WBC count and clotting times were observed in spring, summer, spring, spring and winter, respectively. The minimum amounts of these factors were counted in summer, winter, winter, winter and winter, respectively. Blood Samples were taken from healthy smolt, immature and adult Caspian salmon in spawning time. Hematological determinations and biochemical serum analysis were performed in 101 fish in the three samples. The ranges of hematological values for sample mean were counted. Red blood cell counts were 866600 mm3 and 1259400 mm3 in smolt and adult respectively. Hematocrit was 48.39% in smolt and 44.29% in adult. Hemoglobin was 8.85 gr/dl in smolt and 10.91 gr/dl in adult. White blood cell count was 8781.58 mm3 in smolt and 5217.55 mm3 in adult and mean were differential of WBC, Lymphocyte 90.57%in smolt and73.22% in adult. Neutrophil was 5.12% in smolt and 16.92% in adult, Monocyte were 1.27% in smolt and 4.24% in adult, Clotting time was 282.34 Seconds in smolt and 291.47 seconds in adult MCV, MCH and MCHC also meagered in smolt and adult. Biochemical parameter in immature and mature Caspian salmon meagered .Glucose concentration was 2.97 mmol.l- in immature and 1.99 mmol.l- in mature .Cholesterol concentration was 4.26 mmol.l- in immature and 7.06 mmol.l- in mature. Triglyceride amount was 2.35 mmol.l- in immature and 2.47 mmol.l- in mature and Calcium was 2.47 in immature and 2.61 mmol.l- in mature. An in situ study was made on erythrocytic isoantigens and hetero-antigen and their corresponding iso-and hetero-antibodies of sera by means of hemoagglutination tests on the blood sample, of 450 immature and 50 mature Caspian salmon. The absence of erythrocyte iso-antigens and hetero-antigen and their corresponding iso-and hetero-antibodies were shown by the experimental. It could be indicated an intra-specific variation and differences in species for kelardasht hatchery.