AN APPARENT 1-YEAR LAG RELATIONSHIP OF HEAVY SNOW YEARS BETWEEN EURASIA AND NORTH AMERICA

• Main Authors: イワサキ トモヒコ, Tomohiko IWASAKI
• Format: Report
• Language: English
• Published: ABSTRACT 1991
• Subjects: Polar meteorology and glaciology; Proceedings of the NIPR Symposium on Polar Meteorology and Glaciology
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=3677; http://id.nii.ac.jp/1291/00003677/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=3677&item_no=1&attribute_id=18&file_no=1

The purpose of this study is to investigate the interannual variability of winter snow cover in the Northern Hemisphere, using the satellite-derived monthly snow cover data from 1967 to 1987. The data were supplied in digitized form by the National Oceanic and Atmospheric Administration/National Environmental Satellite Data Information Service (NOAA/NESDIS). An empirical orthogonal function (EOF) analysis is done to see the typical pattern of snow cover variations during winter. The first component of the EOF (EOF1), which represents about 40% of the total variance, shows concurrent snow cover patterns between Eurasia and North America. The score of the EOF1 is similar to the time series of winter snow cover in the Northern Hemisphere. The second component of the EOF (EOF2), which represents over 20% of the total variance, shows a seesaw pattern between the eastern and western parts of Eurasia and North America. This EOF2 shows the importance of subcontinental-scale snow variation. I examined time series of mean snow cover for key regions of the Northern Hemisphere to investigate variations depicted in the EOF patterns in more detail. We selected two key regions which represent continental-scale snow variation. One is the eastern part of Eurasia and the other is the western part of North America. The time series of the two key regions show an apparent 1-year lag relationship of heavy snow cover years; winters with extensive snow cover over Eurasia tend to be followed by extensive snow cover over North America during the succeeding winters.