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Carbon dioxide, hydrographic, and chemical data obtained during the R/V Meteor Cruise 18/1 in the North Atlantic Ocean (WOCE Section A1E, September 1991)

Description: The North Atlantic Ocean is characterized by an intense meridional circulation cell carrying near-surface waters of tropical and subtropical origin northward and deep waters of arctic and subarctic origin southward. The related {open_quotes}overturning{close_quotes} is driven by the sinking of water masses at high latitudes. The overturning rate and thus the intensity of the meridional transports of mass, heat, and salt, is an important control parameter for the modeling of the ocean`s role in climate. The Research Vessel (R/V) Meteor Cruise 18/1 was one in a series of cruises in the North Atlantic that started in March 1991 and continued until 1995. This data documentation discusses the procedures and methods used to measure total carbon dioxide (TCO{sub 2}) and total alkalinity (TALK) at hydrographic stations, as well as underway partial pressure of CO{sub 2} (pCO{sub 2}) measured during the RIV Meteor Cruise 18/1 in the North Atlantic Ocean (Section A1E). Conducted as part of the World Ocean Circulation Experiment (WOCE) and the German North Atlantic Overturning Rate Determination expedition, the cruise began in Reykjavik, Iceland, on September 2, 1991, and ended after 24 days at sea in Hamburg, Germany, on September 25, 1991. WOCE Zonal Section AlE began at 60{degrees}N and 42{degrees}30{prime} W (southeast of Greenland) and continued southeast with a closely spaced series of hydrocasts to 52{degrees}20{prime} N and 14{degrees}15{prime} W (Porcupine Shelves). Measurements made along WOCE Section AlE included pressure, temperature, salinity, and oxygen measured by a conductivity, temperature and depth (CTD) sensor; bottle salinity; oxygen; phosphate; nitrate; nitrite; silicate; TCO{sub 2}; TALK; and underway pCO{sub 2}. A total of 61 CTD casts were made, including 59 bottle casts and 2 calibration stations.
Date: July 1, 1996
Creator: Johnson, K.M.; Wallace, D.W.R.; Schneider, B.; Mintrop, L. & Kozyr, A.
Partner: UNT Libraries Government Documents Department

Performance of an island seismic station for recording T-phases

Description: As part of the International Monitoring System (IMS) a worldwide hydroacoustic network consisting of 6 hydrophone and 5 island seismic stations has been planned which will monitor for underwater or low altitude atmospheric explosions. Data from this network is to be integrated with other IMS networks monitoring the Comprehensive Nuclear Test-Ban Treaty. The seismic (T-phase) stations are significantly less sensitive than hydrophones to ocean borne acoustic waves. T-phase signal strength at seismic stations depends on the amplitude of the signal in the water column, the hydroacoustic-seismic conversion efficiency, and loss on the seismic portion of the path through the island. In order to understand how these factors influence the performance of T-phase stations seismic and hydroacoustic data are examined from instruments currently deployed on or around Ascension Island in the South Atlantic Ocean. T-phase recordings for the last 3 years have been collected from the GSN seismic station ASCN on Ascension Island. Surrounding the island are 5 hydrophones which are part of the U.S. Air Force Missile Impact Locating System (MILS). Data from this system have been obtained for some of the events observed at ASCN. Four of the hydrophones are located within 30 km of the coast while the fifth instrument is 100 km to the south. Amplitude spectral estimates of the signal-to-noise levels (SNL) are computed and generally peak between 3 and 8 Hz for both the seismometer and hydrophone data. The seismic SNL generally decays to 1 between 10 and 15 Hz while the hydrophone SNL is still large well above 20 Hz. The ratios of the hydrophone-to-seismometer SNL, at their peak in energy, range between 10 and 100 (20-40 dB) unless a hydrophone is partially blocked by the Ascension Island landmass.
Date: May 1, 1998
Creator: Hanson, J. A., LLNL
Partner: UNT Libraries Government Documents Department

Environmental measurements for Project Overview

Description: From July 10 to July 17, 1995, Project Overview was conducted at the Atlantic Undersea Test and Evaluation Center (AUTEC) at Andros Island, Bahamas. Part of the project was the collection and analysis of environmental data including wind measurements and ocean temperature and salinity profiles. This report describes these environmental measurements and presents the results of analysis performed in the field. The goal of the analysis was to calculate the Brunt-Vaeisaelae (BV) profile during operations, and provide operational recommendations from solutions of the Taylor-Goldstein (T-G) equation using the measured BV profile. Part 1 is a description of the sensors and their deployment. Part 2 discusses the analysis done in the field. Part 3 presents a summary of the wind measurements. Part 4 summarizes the ocean profiling results. Part 5 presents overall conclusions and recommendations for future experiments. The appendices include all of the ocean profiling results and wind measurements obtained in the field.
Date: September 28, 1995
Creator: Chambers, D.H. & Ravizza, D.L.
Partner: UNT Libraries Government Documents Department

On the diurnal characteristics of cloud structure in the marine stratocumulus transition regime

Description: It is known that stratus-topped marine boundary layers in the mid- latitudes are subject to significant diurnal changes in structure caused by solar heating. One characteristic of the transition cloud regime that has been thoroughly explored is its diurnal variability. Although this variability has been discussed in other studies, the size of the database was restrictive. Thus, it is of importance to examine the diurnal characteristics of transition cloud structure in a larger data sample to validate the conclusions of these previous studies and to enhance our understanding of the effects of this diurnal variability on the climatology of the transition itself. The Atlantic Stratocumulus Transition Experiment (ASTEX) was designed to help understand transition clouds by making comprehensive measurements of their structure over a one-month period. Data was collected using a suite of in-situ and surface-based remote sensors deployed on the island of Santa Maria.
Date: July 1, 1996
Creator: Miller, M.A.
Partner: UNT Libraries Government Documents Department

Comparison of Inorganic Carbon System Parameters Measured in the Atlantic Ocean from 1990 to 1998 and Recommended Adjustments

Description: As part of the global synthesis effort sponsored by the Global Carbon Cycle project of the National Oceanic and Atmospheric Administration (NOAA) and U.S. Department of Energy, a comprehensive comparison was performed of inorganic carbon parameters measured on oceanographic surveys carried out under auspices of the Joint Global Ocean Flux Study and related programs. Many of the cruises were performed as part of the World Hydrographic Program of the World Ocean Circulation Experiment and the NOAA Ocean-Atmosphere Carbon Exchange Study. Total dissolved inorganic carbon (DIC), total alkalinity (TAlk), fugacity of CO{sub 2}, and pH data from twenty-three cruises were checked to determine whether there were systematic offsets of these parameters between cruises. The focus was on the DIC and TAlk state variables. Data quality and offsets of DIC and TAlk were determined by using several different techniques. One approach was based on crossover analyses, where the deep-water concentrations of DIC and TAlk were compared for stations on different cruises that were within 100 km of each other. Regional comparisons were also made by using a multiple-parameter linear regression technique in which DIC or TAlk was regressed against hydrographic and nutrient parameters. When offsets of greater than 4 {micro}mol/kg were observed for DIC and/or 6 {micro}mol/kg were observed for TAlk, the data taken on the cruise were closely scrutinized to determine whether the offsets were systematic. Based on these analyses, the DIC data and TAlk data of three cruises were deemed of insufficient quality to be included in the comprehensive basinwide data set. For several of the cruises, small adjustments in TAlk were recommended for consistency with other cruises in the region. After these adjustments were incorporated, the inorganic carbon data from all cruises along with hydrographic, chlorofluorocarbon, and nutrient data were combined as a research quality product for the scientific ...
Date: May 21, 2003
Creator: Wanninkhof, R.
Partner: UNT Libraries Government Documents Department

Carbon Dioxide, Hydrographic, and Chemical Data Obtained During the R/V Meteor Cruise 28/1 in the South Atlantic Ocean (WOCE Section A8, March 29 - May 12, 1994)

Description: This data documentation discusses the procedures and methods used to measure total carbon dioxide (TCO{sub 2}) and the fugacity of CO{sub 2} (fCO{sub 2}) at hydrographic stations during the R/V Meteor oceanographic cruise 28/1 in the South Atlantic Ocean (Section A8). Conducted as part of the World Ocean Circulation Experiment (WOCE), the cruise began in Recife, Brazil, on March 29, 1994, and ended after 35 days at sea in Walvis Bay, Namibia, on May 12, 1994. Instructions for accessing the data are provided. TCO{sub 2} was measured using two single-operator multiparameter metabolic analyzers (SOMMA) coupled to a coulometer for extracting and detecting CO{sub 2} from seawater samples. The overall precision and accuracy of the analyses was {+-}1.17 {micro}mol/kg. For the second carbonate system parameter, the fCO{sub 2} was measured in discrete samples by equilibrating a known volume of liquid phase (seawater) with a known volume of a gas phase containing a known mixture of CO{sub 2} in gaseous nitrogen (N{sub 2}). After equilibration, the gas phase CO{sub 2} concentration was determined by flame ionization detection following the catalytic conversion of CO{sub 2} to methane (CH{sub 4}). The precision of these measurements was less than or equal to 1.0%. The R/V Meteor Cruise 28/1 data set is available free of charge as a numeric data package (NDP) from the Carbon Dioxide Information Analysis Center. The NDP consists of two oceanographic data files, two FORTRAN 90 data retrieval routine files, a readme file, and this printed documentation that describes the contents and format of all files as well as the procedures and methods used to obtain the data.
Date: May 9, 2002
Creator: Kozyr, A.
Partner: UNT Libraries Government Documents Department

Carbon Dioxide, Hydrographic, and Chemical Data Obtained During the R/V Hesperides Cruise in the Atlantic Ocean

Description: This data documentation discusses the procedures and methods used to measure total carbon dioxide (TCO{sub 2}), total alkalinity (TALK), and pH at hydrographic stations during the R/V Hesperides oceanographic cruise in the Atlantic Ocean (Section A5). Conducted as part of the Work Ocean Circulation Experiment (WOCE), the cruise began in Cadiz, Spain, on July 14, 1992, and ended in Miami, Florida, on August 15, 1992. Measurements made along WOCE Section A5 included CTD pressure, temperature, salinity, and oxygen; and bottle salinity, oxygen, phosphate, nitrate, nitrite, silicate, TCO{sub 2}, TALK, and pH. The TALK, TCO{sub 2}, and pH were determined from titrations of seawater collected at 33 stations. The titration systems for measuring TALK and TCO{sub 2} were calibrated in the laboratory with certified reference materials (CRMs) before the cruise to ensure traceable results. Standard reference seawater provided by Andrew Dickson of Scripps Institution of Oceanography (SIO) was used at sea to monitor the performance of the titration systems. The results agree with the laboratory results to {+-} 2 {micro}mol/kg for TALK and {+-} 1 {micro}mol/kg for TCO{sub 2}. The titration systems used to measure pH were calibrated with TRIS seawater buffers prepared in the laboratory and measured with an H{sub 2}, Pt/AgCl, Ag electrode. The initial electromotive force (emf) of the titrations was used to determine the pH. The values of pH are thought to be reliable to {+-} 0.01 and are internally consistent with the measured values of TALK and TCO{sub 2} to {+-} 7 {micro}mol/kg. The measured carbon dioxide system parameters have been used to calculate the in situ values of the fugacity of CO{sub 2} (fCO{sub 2}) for the surface water. The surface results are briefly discussed.
Date: June 9, 2000
Creator: Millero, F.J.
Partner: UNT Libraries Government Documents Department

Carbon dioxide, hydrographic, and chemical data from the F/S Meteor Cruise No. 18 in the North Atlantic Ocean (WOCE Section A1/E) during September 1991

Description: This report presents the procedures and methods used to obtain total carbon dioxide (C{sub T}), total alkalinity, and underway pCO{sub 2} data during the F/S Meteor Cruise 18 in the North Atlantic Ocean (WOCE Section A1/E). The F/S Meteor departed Reykjavik on September 2, 1991 and docked in Hamburg early on the morning of September 25, 1991 after 24 days at sea. A two day steam from Reykjavik brought the ship to the starting position for WOCE zonal section A1/east (A1/E) on September 5. Section work began and ended with a closely spaced series hydrocasts on the SE-Greenland (60{degree}N 42{degree}30 minutes W) and Porcupine Shelves (52{degree}20 minutes N 14{degree}15 minutes W), respectively. The cast schedule was interrupted for equipment problems (6 and 7 September), current meter deployments (9, 10, 11, 14, and 19 September), and by high seas (13, 14, and 17 September). Of 64 CTD casts made, 58 were bottle casts including two calibration stations. Measurements made included CTD pressure, temperature, salinity, bottle salinity, oxygen, phosphate, nitrate, nitrite, silicate, total alkalinity, CFC`S, total carbon dioxide, and continuous underway pCO{sub 2} of surface waters. Carbonate samples were collected from 31 section stations (55.4% of the section stations), one test station, and two calibration stations. Repeated XBT, and ADCP profiles were taken throughout the cruise. Instructions for accessing the data are provided.
Date: August 1, 1995
Creator: Johnson, K.M.; Wallace, D.W.R.; Schneider, B. & Mintrop, L.
Partner: UNT Libraries Government Documents Department

Measurements of Surface Ocean Carbon Dioxide Partial Pressure During WOCE

Description: All of the technical goals of the World Ocean Circulation Experiment (WOCE) field program which were supported under the Department of Energy research grant ''Measurements of Surface Ocean Carbon Dioxide Partial Pressure During WOCE'' (DE-FG03-90ER60981) have been met. This has included the measurement of the partial pressures of carbon dioxide (C0{sub 2}) and nitrous oxide (N{sub 2}O) in both the surface ocean and the atmosphere on 24 separate shipboard expedition legs of the WOCE Hydrographic Programme. These measurements were made in the Pacific, Indian and Atlantic Oceans over a six-and-a-half year period, and over a distance of nearly 200,000 kilometers of ship track. The total number of measurements, including ocean measurements, air measurements and standard gas measurements, is about 136,000 for each gas, or about 34,000 measurements of each gas in the ocean and in the air. This global survey effort is directed at obtaining a better understanding of the role of the oceans in the global atmospheric budgets of two important natural and anthropogenic modulators of climate through the ''greenhouse effect'', CO{sub 2} and N{sub 2}O, and an important natural and anthropogenic modulator of the Earth's protective ozone layer through catalytic processes in the stratosphere, N{sub 2}O. For both of these compounds, the oceans play a major role in their global budgets. In the case of CO{sub 2}, roughly half of the anthropogenic production through the combustion of fossil fuels has been absorbed by the world's oceans. In the case of N{sub 2}O, roughly a third of the natural flux to the atmosphere originates in the oceans. As the interpretation of the variability in the oceanic distributions of these compounds improves, measurements such as those supported by this research project are playing an increasingly important role in improving our understanding of natural and anthropogenic influences on climate and ozone. ...
Date: October 15, 1998
Creator: Weiss, R.F.
Partner: UNT Libraries Government Documents Department

A Chart of the Gulf Stream

Description: Map of the Gulf Stream from Florida and the Bahama Islands at lower left of map, up along the coast of North America, and to Newfoundland and the Grand Banks at upper right of map, as charted by Benjamin Franklin. At left side is text describing the journey from Newfoundland west and south along the Atlantic coast. In the text, "Gulf" is spelled "Gulph" Labrador is labeled as "Land of the Eskimaux's". Inset at upper left is a map of the Atlantic Ocean, showing the Gulf Stream.
Date: 1786
Creator: Franklin, Benjamin, 1706-1790
Partner: UNT Libraries

Carbon 14 measurements in surface water CO{sub 2} from the Atlantic, India, and Pacific Oceans, 1965--1994

Description: In the 1960s, thermonuclear bomb tests released significant pulses of radioactive carbon-14 ({sup 14}C) into the atmosphere. These major perturbations allowed scientists to study the dynamics of the global carbon cycle by calculating rates of isotope exchange between the atmosphere and ocean waters. A total of 950 ocean surface water observations were made from 1965 through 1994. The measurements were taken at 30 stations in the Atlantic Ocean, 14 stations in the Indian Ocean, and 38 stations in the Pacific Ocean. Thirty-two of the 950 samples were taken in the Atlantic Ocean during the R/V Andenes research cruise. {sup 14}C was measured in 871 of the 950 samples, and those measurements have been corrected ({Delta}{sup 14}C) for isotopic fractionation and radioactive decay. The {Delta}{sup 14}C values range between {minus}113.3 and 280.9 per mille and have a mean value of 101.3 per mille. The highest yearly mean (146.5 per mille) was calculated for 1969, the lowest yearly mean value was calculated for 1990 (67.9 per mille) illustrating a decrease over time. This decrease was to be expected as a result of the ban on atmospheric thermonuclear tests and the slow mixing of the ocean surface waters with the deeper layers.
Date: March 1, 1998
Creator: Nydal, R.; Brenkert, A.L. & Boden, T.A.
Partner: UNT Libraries Government Documents Department

Assessment of MTI Water Temperature Thermal Discharge Retrievals with Ground Truth

Description: Surface water temperatures calculated from Multispectral Thermal Imager (MTI) brightness temperatures and the robust retrieval algorithm, developed by the Los Alamos National Laboratory (LANL), are compared with ground truth measurements at a mid-latitude cold-water site along the Atlantic coast near Plymouth, MA. In contrast to the relative uniformity of the sea-surface temperature in the open ocean the water temperature near Pilgrim exhibits strong spatial gradients and temporal variability. This made it critical that all images be accurately registered in order to extract temperature values at the six buoy locations. Sixteen images during a one-year period from August 2000 to July 2001 were selected for the study. The RMS error of Pilgrim water temperature is about 3.5 C for the 4 buoys located in open water. The RMS error of the combined temperatures from 3 of the open-water buoys is 2.8 C. The RMS error includes errors in the ground truth. The magnitude of this error is estimated to range between 0.8 and 2.3 C. The two main components of this error are warm-layer effect and spatial variability. The actual error in the MTI retrievals for Pilgrim daytime conditions is estimated to be between 2.7 and 3.4 C for individual buoys and between 1.7 and 2.7 C for the combined open-water buoys.
Date: December 6, 2002
Creator: Kurzeja, R.J.
Partner: UNT Libraries Government Documents Department

The Ascension Island hydroacoustic experiment: purpose, data set features and plans for future analysis

Description: Calibration of hydroacoustic and T-phase stations for Comprehensive Nuclear-Test-Ban Treaty (CTBT) monitoring will be an important element in establishing new operational stations and upgrading existing stations. Calibration of hydroacoustic stations is herein defined as precision location of the hydrophones and determination of the amplitude response from a known source energy. T-phase station calibration is herein defined as a determination of station site attenuation as a function of frequency, bearing, and distance for known impulsive energy sources in the ocean. To understand how to best conduct calibration experiments for both hydroacoustic and T-phase stations, an experiment was conducted in May, 1999 at Ascension Island in the South Atlantic Ocean. The experiment made use of a British oceanographic research vessel and collected data that will be used for CTBT issues and for fundamental understanding of the Ascension Island volcanic edifice.
Date: July 23, 1999
Creator: Harben, P E; Rock, D & Rodgers, A J
Partner: UNT Libraries Government Documents Department

Carbon Dioxide, Hydrographic, and Chemical Data Obtained During the R/V Meteor Cruise 22/5 in the South Atlantic Ocean (WOCE Section A10, December 1992-January 1993)

Description: This data documentation discusses the procedures and methods used to measure total carbon dioxide (TCO{sub 2}) and total alkalinity (TALK) at hydrographic stations, as well as the underway partial pressure of CO{sub 2} (pCO{sub 2}) during the R/V Meteor Cruise 22/5 in the South Atlantic Ocean (Section A10). Conducted as part of the World Ocean Circulation Experiment (WOCE), the cruise began in Rio de Janeiro on December 27, 1992, and ended after 36 days at sea in Capetown, South Africa, on January 31, 1993. Measurements made along WOCE Section A10 included pressure, temperature, and salinity [measured by conductivity, temperature, and depth (CTD) sensor], bottle salinity, bottle oxygen, phosphate, nitrate, nitrite, silicate, chlorofluorocarbons (CFC-1 1 , CFC-12), TCO{sub 2}, TALK, and underway pCO{sub 2}. The TCO{sub 2} was measured by using two Single-Operator Multiparameter Metabolic Analyzers (SOMMAs) for extracting CO{sub 2} from seawater samples that were coupled to a coulometer for detection of the extracted CO{sub 2}. The overall precision and accuracy of the analyses was {+-} 1.9 {micro}mol/kg. Samples collected for TALK were measured by potentiometric titration; precision was {+-}2.0 {micro}mol/kg. Underway pCO{sub 2} was measured by infrared photometry with a precision of {+-} 2.0 {micro}atm. The work aboard the R/V Meteor was supported by the U.S. Department of Energy under contract DE-AC02-76CHOO016, and the Bundesministerium fir Forschung und Technologies through grants 03F0545A and MPG 099/1.
Date: December 1, 1998
Creator: Kozyr, A.
Partner: UNT Libraries Government Documents Department

The International Intercomparison Exercise of Underway fCo2 Systems During the R/V Meteor Cruise 36/1 in the North Atlantic Ocean

Description: Measurements of the fugacity of carbon dioxide (fCO2) in surface seawater are an important part of studies of the global carbon cycle and its anthropogenic perturbation. An important step toward the thorough interpretation of the vast amount of available fCO2 data is the establishment of a database system that would make sure measurements more widely available for use in understanding the basin- and global-scale distribution of fCO2 and its influence on the oceanic uptake of anthropogenic CO2. Such an effort, however, is based on knowledge of data sets from different laboratories. Currently, however, there is not much known about this subject.
Date: March 1, 1999
Creator: Koertzinger, Arne; Mintrop, Ludger & Duinker, Jan
Partner: UNT Libraries Government Documents Department

Massively parallel implementation of a high order domain decomposition equatorial ocean model

Description: The present work is about the algorithms and parallel constructs of a spectral element equatorial ocean model. It shows that high order domain decomposition ocean models can be efficiently implemented on massively parallel architectures, such as the Connection Machine Model CM5. The optimized computational efficiency of the parallel spectral element ocean model comes not only from the exponential convergence of the numerical solution, but also from the work-intensive, medium-grained, geometry-based data parallelism. The data parallelism is created to efficiently implement the spectral element ocean model on the distributed-memory massively parallel computer, which minimizes communication among processing nodes. Computational complexity analysis is given for the parallel algorithm of the spectral element ocean model, and the model's parallel performance on the CM5 is evaluated. Lastly, results from a simulation of wind-driven circulation in low-latitude Atlantic Ocean are described.
Date: June 1, 1999
Creator: Ma, H.; McCaffrey, J.W. & Piacsek, S.
Partner: UNT Libraries Government Documents Department

Siting Study Framework and Survey Methodology for Marine and Hydrokinetic Energy Project in Offshore Southeast Florida

Description: Dehlsen Associates, LLC was awarded a grant by the United States Department of Energy (DOE) Golden Field Office for a project titled 'Siting Study Framework and Survey Methodology for Marine and Hydrokinetic Energy Project in Offshore Southeast Florida,' corresponding to DOE Grant Award Number DE-EE0002655 resulting from DOE funding Opportunity Announcement Number DE-FOA-0000069 for Topic Area 2, and it is referred to herein as 'the project.' The purpose of the project was to enhance the certainty of the survey requirements and regulatory review processes for the purpose of reducing the time, efforts, and costs associated with initial siting efforts of marine and hydrokinetic energy conversion facilities that may be proposed in the Atlantic Ocean offshore Southeast Florida. To secure early input from agencies, protocols were developed for collecting baseline geophysical information and benthic habitat data that can be used by project developers and regulators to make decisions early in the process of determining project location (i.e., the siting process) that avoid or minimize adverse impacts to sensitive marine benthic habitat. It is presumed that such an approach will help facilitate the licensing process for hydrokinetic and other ocean renewable energy projects within the study area and will assist in clarifying the baseline environmental data requirements described in the U.S. Department of the Interior Bureau of Ocean Energy Management, Regulation and Enforcement (formerly Minerals Management Service) final regulations on offshore renewable energy (30 Code of Federal Regulations 285, published April 29, 2009). Because projects generally seek to avoid or minimize impacts to sensitive marine habitats, it was not the intent of this project to investigate areas that did not appear suitable for the siting of ocean renewable energy projects. Rather, a two-tiered approach was designed with the first step consisting of gaining overall insight about seabed conditions offshore southeastern Florida by ...
Date: February 28, 2012
Creator: Vinick, Charles; Riccobono, Antonino; Messing, Charles G.; Walker, Brian K. & Reed, John K.
Partner: UNT Libraries Government Documents Department

Atlantic Coastal Experiment III: R/V KNORR cruise 68, 4-30 August 1977; FRV ALBATROSS IV cruise 77-07, 1-4, 16-31 August 1977. Data Report, volume 2.

Description: Data are reported from KNORR cruise 88, the major investigation of the third Atlantic Coastal Experiment (ACE), conducted during a period of pronounced water-column stratification.
Date: March 1, 1983
Creator: Judkins, D.C. & von Bock, K.
Partner: UNT Libraries Government Documents Department

Atlantic coastal experiment, phytoplankton species composition: 1976-1978, data report

Description: Phytoplankton samples are routinely taken at every station on Brookhaven oceanographic cruises. On productivity stations samples are taken from every depth, while on hydrographic stations samples are taken from the surface and some fixed depth (e.g. 20 m). The 125 ml samples are drawn as soon as possible after the cast from Niskin bottles and preserved with 2-3 ml of Lugol's solution. The samples are left in dark boxes in cool areas until counted. For counting, 10 ml subsamples are settled in Uttermohl chambers, usually within three months after the cruise, and counted with an inverted microscope equipped with phase contrast illumination. Between one-half and the entire chamber are counted, depending on the cell density. This data report is a listing of the phyto- plankton counts from selected stations and cruises between 1976 and 1978, inclusive.
Date: June 1, 1979
Creator: Falkowski, P. & von Bock, K. (eds.)
Partner: UNT Libraries Government Documents Department

Aerosol sulfate loading and shortwave direct radiative forcing over the North Atlantic Ocean

Description: Shortwave radiative forcing of climate by anthropogenic sulfate aerosols is estimated to be equal in magnitude but opposite in sign to that of greenhouse warming, with a global annual average value of approximately -1 W m{sup -2} uncertain to at least a factor of two. Estimates of the 2 contributions to this forcing by the direct effect are -0.4 W m{sup -2}. It is therefore necessary to accurately and efficiently represent this forcing in climate models, specifically including spatial and temporal variability. Here we explore a method to expedite the process for determining this forcing. The method utilizes an approach where the forcing is computed precisely at several discrete radii (r) and then integrated over an arbitrary aerosol size distribution. Additionally, the forcing is calculated at several values of relative humidity (RH), solar zenith angle (SZA), and aerosol optical thickness ({tau}). The parameters can be interpolated to provide the forcing at specific intermediate values. Alternatively, an empirical relationship between the forcing and the above mentioned variables can be utilized to further reduce computation time. At present, the calculations are restricted to ammonium sulfate particles over an ocean surface. The advantage of the ocean surface is the constant and low albedo compared to the highly variable albedo of land surfaces. Ultimately, the sensitivity of forcing to surface albedo and composition will be included.
Date: March 1, 1997
Creator: Nemesure, S.; Benkovitz, C.M. & Schwartz, S.E.
Partner: UNT Libraries Government Documents Department

Carbon dioxide, hydrographic, and chemical data obtained during the R/V Meteor Cruise 22/5 in the South Atlantic Ocean (WOCE Section A10, December 1992--January 1993)

Description: This documentation discusses the procedures and methods used to measure total carbon dioxide (TCO{sub 2}), total alkalinity at Hydrographic stations as well as the underway partial pressure of CO{sub 2} (pCO{sub 2}) during the R/V Meteor Cruise M22/5 in the South Atlantic Ocean (Section A10). Conducted as part of the World Ocean Circulation Experiment (WOCE), the cruise began in Rio de Janeiro on 27 December 1992, and ended after 36 days at sea in Capetown, South Africa on 31 January 1993. Instructions for accessing the data are provided. TCO{sub 2} was measured using tow automated sample processors for extracting CO{sub 2} from seawater samples which were coupled to a Coulometer for detection of the extracted CO{sub 2}. The overall precision and accuracy of the analyses was {+-} 1.9 {micro}mol/kg. Samples collected for total alkalinity were measured by potentiometric titration; precision was {+-} 2.0 {micro}mol/kg. Underway pCO{sub 2} was measured by Infra Red (IR) Photometry; precision was {+-} 2.0 {micro}atm. From these cruises the large-scale three-dimensional distribution of temperature, salinity, and chemical constituents, including the carbonate system parameters will be mapped. Knowledge of these parameters and their initial conditions will allow determination of heat and water transports as well as carbon transport. An understanding of these transports will contribute to the understanding of processes which are relevant for climate change. This section in the South Atlantic subtropical Gyre is especially relevant for CO{sub 2} transport because it crosses both the Brazil and the Benguela Boundary Currents.
Date: April 1, 1997
Creator: Johnson, K.M.; Wallace, D.W.R.; Schneider, B. & Mintrop, L.
Partner: UNT Libraries Government Documents Department

MASSIVELY PARALLEL IMPLEMENTATION OF A HIGH ORDER DOMAIN DECOMPOSITION EQUATORIAL OCEAN MODEL

Description: The present work is about the algorithms and parallel constructs of a spectral element equatorial ocean model. It shows that high order domain decomposition ocean models can be efficiently implemented on massively parallel architectures, such as the Connection Machine Model CM5. The optimized computational efficiency of the parallel spectral element ocean model comes not only from the exponential convergence of the numerical solution, but also from the work-intensive, medium-grained, geometry-based data parallelism. The data parallelism is created to efficiently implement the spectral element ocean model on the distributed-memory massively parallel computer, which minimizes communication among processing nodes. Computational complexity analysis is given for the parallel algorithm of the spectral element ocean model, and the model's parallel performance on the CM5 is evaluated. Lastly, results from a simulation of wind-driven circulation in low-latitude Atlantic ocean are described.
Date: July 15, 1998
Creator: MA,H.; MCCAFFREY,J.W. & PIACSEK,S.
Partner: UNT Libraries Government Documents Department