Enhancing NASA's Contributions to Polar Science A Review of Polar Geophysical Data Sets (2001) / Chapter Skim
Currently Skimming:
2. Overview of NASA Data Sets
2. Overview of NASA Data Sets
Pages 21-43
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 21... ...
2 Overview of NASA Data Sets As a first step in assessing data sets with relevance to research in high latitudes, it is important to describe the broad context that is, to introduce NASA's Earth Science Enterprise (ESE) and to provide examples to illustrate the great diversity of available and expected products.
|
From page 22... ...
These products, together with the detailed listings of data sets held at the National Snow and Ice Data Center (NSIDC) and the Alaska Synthetic Aperture Radar Facility (ASF)
|
From page 23... ...
RADARSAT Antarctic Mapping Project The RADARSAT Antarctic Mapping Project (RAMP) , a collaboration between the Canadian Space Agency and NASA, has created the first seamless, high-resolution-radar, map-quality mosaic of Antarctica (see Figure 2-1~.
|
From page 25... ...
The remaining frames were acquired after one repeat cycle of the satellite, and are suitable for interferometric analysis of ice sheet motion. RAMP has produced some notable scientific accomplishments, such as identifying the southward extent of the East Antarctic Ice Streams and measuring the extent of physical properties of snow dunes and their contributions to mass transport.
|
From page 26... ...
Participants in the RADARSAT Antarctic Mapping Project activity were the Canadian Space Agency, NASA, The Ohio State University, ret Propulsion Laboratory, Alaska SAR Facility, Vexcel Corporation, Goddard Space Flight Center, Canadian Center for Remote Sensing, Environmental Research Institute of Michigan, and RADARSAT International. The project received scientific and technical support from many organizations in a wide range of nations: British Antarctic Survey (Cambridge)
|
From page 27... ...
OVERVIEW OF NASA DATA SETS 27 Program for Arctic Regional Climate Assessment The Program for Arctic Regional Climate Assessment (PARCA) is a NASA project with the goal of measuring and understanding the mass balance of the Greenland ice sheet.
|
From page 28... ...
, velocity measurements around the ice-sheet perimeter at an elevation of about 2,000 m, local measurements of ice thickening and thinning rates, and climatological observations from automatic weather stations. Data from various satellite sensors are also used: elevation change from satellite radar altimetry; mapping of snow facies and zones of summer melt from passive and active microwave; ice velocities from interferometric SAR and from repeat high-resolution visible and SAR imagery; and mapping surface and 10-m temperatures, accumulation rates, and surface albedo from microwave and AVHRR data.
|
From page 29... ...
According to a recent review, each DAAC has an individual role in some part of the overall Goddard Space Flight Center DAAC, Langley Research Center DAAC, Eros Data Center DAAC, Alaska SAR Facility DAAC, Physical Oceanography DAAC, National Snow and Ice Center DAAC, and Oak Ridge National Laboratory DAAC.
|
From page 30... ...
This DAAC, which manages data related to snow and ice, climate, and the cryosphere, was created by NASA in 1991, although its roots go back to 1957 when the World Data Center for Glaciology was established at the American Geographical Society in New York. All three NSIDC centers serve the cryospheric and polar science communities, and data are available on snow cover, freshwater ice, sea ice, glaciers, ice sheets, and ground ice (Box 2-4~.
|
From page 31... ...
All other NASA DAACs hold global data sets that are directly relevant to polar studies, but NASA and polar researchers do not think of them in this light. Two examples are particularly notable because the need for them is frequently mentioned in both the science-driving ques
|
From page 34... ...
The most extensive global data set that contains polar cloud information is produced by the International Satellite Cloud Climatology Project (ISCCP) , which is archived at the NASA Langley DAAC.
|
From page 36... ...
The committee believes that the DAACs should be the permanent archives for satellite-derived data sets to which NASA has been the dominant contributor, for example, the 22-year record of sea ice concentrations from passive microwave sensors. INTERNATIONAL DATA SETS To appreciate NASA's contribution to satellite data sets, it is necessary to consider the international context because there are a number of relevant satellite missions by other nations, as well as various projects with significant international components.
|
From page 37... ...
; RADARSAT Geophysical Processing System - RGPS, Alaska SAR Facility (ASF) , the Department of Fisheries and Oceans Canada (Canadian Coast Guard)
|
From page 38... ...
International Satellite Cloud Climatology Project The International Satellite Cloud Climatology Project was established in 1982 as part of the WCRP to collect and analyze satellite radiance measurements to infer the global distribution of clouds, their properties,
|
From page 39... ...
Note that calculation of radiative fluxes under the severe conditions in polar regions is difficult. The main problems are accurate determination of cloud optical thicknesses, which affect shortwave fluxes the most, and proper determination of lower atmosphere temperature inversions and surface temperature, which affect longwave fluxes the most.
|
From page 40... ...
Water vapor plays a vital role in shaping weather and climate, and this project is intended to improve understanding of fundamental aspects of the atmospheric system, including radiative heating, precipitation, cloud formation, and horizontal and vertical moisture transport and convergence. This project seeks to improve the accuracy and availability of global water vapor data through the development of a global water vapor data set, establish reference stations, and conduct intercomparison of studies among the existing water vapor data sets.
|
From page 41... ...
produces the RADARSAT Eulerian ice motion data set for Surface Heat Budget of the Arctic project (SHEBA)
|
From page 42... ...
Future International Satellite Missions There are a number of potentially significant international satellite missions planned for the near-future that should provide data important to polar scientists. For example, ADEOS-II is a Japanese follow-on mission to ADEOS-I.
|
From page 43... ...
for precipitation, columnar water vapor and cloud water, aerosol properties, sea surface wind speed, snow depth on sea ice, and snow water equivalent; a Moderate-Resolution Imaging Spectroradiometer (MODIS) for atmospheric profiles, land surface characteristics, ocean primary productivity, and snow and ice albedo; and a Clouds and the Earth Radiant Energy System (CERES)
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.