Arctic Research Overview
- The Arctic as a research target
- Comparison of the Arctic with the Antarctic
- Utilization of satellite data
- Collaboration between field works and satellite observation
Utilizing satellite data
Data from earth observation satellites are frequently used in the arctic research. Sensors on these satellites observe various properties of the earth and human activity: vegetation, topography, faults, temperature distribution of volcanoes, fluids and moisture, glaciers, polar ice, sea ice distribution, sea surface temperature, water quality, atmosphere, and growth process of a city. Ground-based stations receive these data and process them into images to make complicated physical properties recognizable.
One advantage of using satellites for arctic research is to obtain data of a much broader area at one time than an airplane. The other is that it can observe inaccessible locations and extreme environments. Satellite data are competent for the arctic research on this point. Recently, a lot of images including commercial data are released from the International Charter to determine the extent of the damage by a major disaster, which is another example of utilizing satellite data for an inapproachable place.
Artist's illustration of ALOS
Advanced Microwave Scanning Radiometer for EOS (AMSR-E) and Precipitation Radar (PR) developed by JAXA on-board NASA's EOS-Aqua and TRMM are operated now.
Additionally, JAXA's Advanced Land Observing Satellite (ALOS) was launched at 10:33 a.m. on January 24, 2006 (Japan Standard Time, JST) from Tanegashima Space Center by H-IIA Launch Vehicle No. 8 with high expectation. The name "Daichi" was chosen from the public. Three state-of-the-art sensors, i.e., the Panchromatic Remote-sensing Instrument for Stereo Mapping (PRISM), the Advanced Visible and Near Infrared Radiometer-2 (AVNIR-2), and the Phased Array type L-band Synthetic Aperture Radar (PALSAR) are on-board. Highly precise data and their contribution for the arctic research are awaited.
Collaboration between field works and satellite observation
Satellite data should be confirmed by ground truth measurements. We could have more definitive result by simultaneous observations from satellites and on the land. This is an example of such research collaboration.
Investigation of snow coverage
Investigation of snow coverage was took place in Barrow (71.17°N, 156.47°W) from April 12 to 27, 2003, the season of melting and refreezing of snow.
Observation site was a vast tundra field 3km away from Barrow. Observation tools were carried by sleds and a snowmobile.
On the site, snow crystals in different depth were collected. The team studied about their size, temperature, contamination, and quality. Though it was warmer than usual the year and mainly cloudy, significant data of the arctic snow coverage were obtained.
The image of Barrow and its vicinity by GLI, ADEOS-II
The other ground observation was took place in conjunction with JAXA's earth observation satellite ADEOS-II, "Midori II", during the two weeks. Data were obtained four times at five points with interval of 1km on two days.
The image captured in April 26 by the Global Imager (GLI) on-board ADEOS-II shows snowy world around Barrow. Black wedge-shape lying in the middle of the picture is seawater. The upper side and lower side are covered by sea ice and tundra snow, respectively.
GLI observed properties of snow and monitored variation of reflectance. It is helpful in elucidating the effect of snow and ice to the local and global climate change.
(Cooperating organizations: Meteorological Research Institute, University of Alaska, Stevens Institute of Technology, Sandia National Laboratories)
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