- Settore: Education
- Number of terms: 34386
- Number of blossaries: 0
- Company Profile:
Founded in 1876, Texas A&M University is a U.S. public and comprehensive university offering a wide variety of academic programs far beyond its original label of agricultural and mechanical trainings. It is one of the few institutions holding triple federal designations as a land-, sea- and ...
A post-LGM European climate regime. This refers to the period from about 6000-3000 BC that spans most of the warmest postglacial times. It is also known as the Postglacial Climatic Optimum. It was preceded by the Boreal period and followed by the Sub-Boreal period.
Industry:Earth science
A narrow, high-speed, westward flow which extends for more than 1000 km along the coast of Alaska. This is a separate feature from the offshore, deepwater Alaskan Stream. It was not recognized as such up until the mid-1970s when a series of hydrocast surveys in the area was begun which led to its identification as a distinct circulation feature. The ACC is driven by freshwater discharge from the mountainous and coastal regions around the Gulf of Alaska and the consequent nearshore confinement of this low-salinity water by westward winds. It is typically narrow (<50 km), shallow (<150 m) and partially baroclinic. It flows most intensely between 145 and 155° W through the Shelikov Strait between the Alaskan Peninsula and Kodiak and Afognak Islands, but extends recognizably along the Peninsula as far as 165° W.
The baroclinic speeds and transports have been estimated as typically <30 cm s<sup>-1</sup> and 0. 4 Sv, respectively, in the winter, spring and summer. In the fall, when the freshwater influx leads to the spin-up of the ACC, the speeds and transports have been estimated as 89-133 cm s<sup>-1</sup> and 1. 0-1. 2 Sv, respectively. Current mooring measurements have yielded estimates of six-month mean total transports ranging from 0. 85 Sv at 151° W to 0. 64 Sv at 155° in Shelikof Strait, with daily means as high as 2. 5 Sv and marked variability from day to day. This variability is thought to be mainly due to variations in wind-forcing caused by the passage of large-scale storms along the coast. The mean baroclinic transport as estimated from the same measurements was found to be about 75% of the total.
Industry:Earth science
A cruise along the rim of the Scotia Sea that took place from March 15 to April 23, 1999 on the RRS James Clark Ross. The aim of the cruise was to study the influence of the Scotia Sea on global ocean circulation by undertaking a detailed hydrographic survey of a box surrounding the Scotia Sea, with CFCs, oxygen isotopes, tritium, helium and nutrients sampled as well as the traditional temperature, salinity and oxygen. The specific goals of ALBATROSS were:
* to determine the pathways of the Weddell Sea Deep Water (WSDW) as it enters and leaves the Scotia Sea;
* to quantify the cooling and freshening of Circumpolar Deep Water (CDW) as it crosses the Scotia Sea;
* to determine the pathway and transport of Southeast Pacific Deep Water (SEPDW) across the Falkland Plateau;
* to measure the transport of the Falkland Current and compare with the transport of the wind stress curl forced western boundary current;
* to compute heat, fresh water and other tracer budgets for the Scotia Sea, southwestern Atlantic and western Weddell Sea;
* the calculate the transport and characterize the fronts associated with the ACC as it enters and leaves the Scotia Sea;
* to determine the interannual variability of the transport and water mass properties of the ACC at Drake Passage; and
* to determine temporal changes to the water masses of the Scotia Sea and the extent to which recently ventilated deep waters may have been affected by climate change.
Industry:Earth science
A non-governmental body including members and participants from research and governmental institutions from several nations. The long-term mission of the AOSB is to facilitate Arctic Ocean research by the support of multinational and multidisciplinary natural science and engineering programs. It was established in May 1984.
Industry:Earth science
A five channel scanning radiometer with channels in the visible, visible near infrared, and infrared water vapor window. These were selected for production of quantitative sea surface temperature products and visible and IR imagery depicting clouds and thermal features, e.g. the Gulf Stream. The AVHRR produces 1 km resolution data.
Industry:Earth science
A component of ACSYS whose goal is to better understand the Arctic atmosphere that provides the dynamic and thermodynamic forcing of the Arctic Ocean circulation and sea ice. The objectives of AAP include:
* to encourage intercomparisons of reanalysis efforts and the assembly of long-term datasets from these intercomparisons;
* to identify shortcomings and implement improvoed parameterizations in the atmospheric modeling systems used for future reanalysis efforts and * to promote intercomparisons of the high latitude performance of climate models;
* to promote the quality control, archiving, updating, publication on CD-ROM, and migration to relevant data centers of key atmospheric datasets;
* to promote strategies for rescue of at-risk atmospheric datasets; and
* provide a polar clouds and radiation program through the GEWEX Clouds and Radiation Panel and other programs.
Industry:Earth science
A research program whose overall objective is to describe and model the biogeochemical processes controlling the dynamics of nutrients (C, N, S, P) and silica in the Southern Ocean. More detailed objectives include investigating the seasonal ice zone, deploying arrays of sediment traps, and studying benthic processes.
The first program cruise, ANTARES I, took place from March 29 to May 18, 1993 on board the R. V. Marion Dufresne. Stops were made at the Kerguelan and Crozet Islands on a ship track that traversed an area between 40° and 60° S and 50° and 75° E in the Southern Ocean. Hydrographic and nutrient data were acquired with rosette hydrocasts and CTD and oxygen profiles were obtained with a Neil Brown Mark III B probe. Various core samples were also taken at a total of 20 stations where 142 hydrological and coring sampling operations were performed.
Industry:Earth science
An effort designed to identify systematic errors in Arctic Ocean models under realistic forcing. The main goals of the proposed research are to examine the ability of Arctic Ocean models to simulate variability on seasonal to interannual scales, and to qualitatively and quantatively understand the behaviour of different Arctic Ocean models. AOMIP's major objective is to use a suite of sophisticated models to simulate the Arctic Ocean circulation for the periods 1946-1998 and 1899-1998. Forcing will use the observed climatology and the daily atmospheric pressure and air temperature fields. Model results will be contrasted and compared to understand model strengths and weaknesses.
Industry:Earth science
The eastern limb of the counterclockwise-flowing subpolar gyre in the North Pacific. This current is concentrated on the shelf region by the freshwater input from Alaskan rivers which enhances the pressure gradient across it. It is strongest in winter with current speeds around 0. 3 m/s and weakest in July and August when prevailing winds tend to oppose its flow. This current may or may not be distinguished from a western boundary current flowing along the Aleutian Islands and called the Alaskan Stream. Both have previously gone by the name of Aleutian Current. Whether or not the nomenclature makes a distinction, the Alaskan Stream and Current do have distinguishing characteristics. The Current is shallow and highly variable while the Stream is steadier and reaches to the ocean floor. The more barotropic nature of the latter is evidence that it is indeed a product of western boundary current dynamics while the former is in an eastern boundary regime.
Industry:Earth science
In physical oceanography, a water mass type which fills the deep basins in the Arctic Sea at depths less than 3000 m. Its formation process involves the interplay of two sources, GSDW and water from the Arctic shelf regions. The salinities of ABW are generally close to 34. 95 but highest in the Canada Basin. The potential temperature in most basins is between -0. 8° C and -0. 9° C, although the Lomonossov Ridge prevents ABW colder than -0. 4° C from entering the Canada Basin. Its main impact in the overall ocean circulation is its contribution to the formation of NADW in the depth range between 1000 m and 4000 m.
Industry:Earth science
