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A remarkable snow climate exists on the Japanese islands of Honshu and Hokkaido near the Sea of Japan. Mean annual snowfall in this “gosetsu chitai” (heavy snow area) exceeds 600 cm (235 in.) in some near-sea-level cities and 1,300 cm (512 in.) in some mountain areas. Much of this snow falls from December to February during the East Asian winter monsoon when frequent cold-air outbreaks occur over the Sea of Japan. The resulting sea-effect precipitation systems share similarities with lake-effect precipitation systems of the Laurentian Great Lakes of North America, but are deeper, are modulated by the regional coastal geometry and topography, and can sometimes feature transversal mode snowbands. Snowfall can maximize in the lowlands or the adjoining mountains depending on the direction and strength of the boundary layer flow. Remarkable infrastructure exists in Japan for public safety, road and sidewalk maintenance, and avalanche mitigation, yet snow-related hazards claim more than 100 lives annually. For winter recreationists, there is no surer bet for deep powder than the mountains of Honshu and Hokkaido near the Sea of Japan in January, but the regional snow climate is vulnerable to global warming, especially in coastal areas. Historically, collaborative studies of sea- and lake-effect precipitation systems involving North American and Japanese scientists have been limited. Significant potential exists to advance our understanding and prediction of sea- and lake-effect precipitation based on studies from the Sea of Japan region and efforts involving meteorologists in North America, Japan, and other sea- and lake-effect regions.
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Characteristics of Sea‐Effect Clouds and Precipitation Over the Sea of Japan Region as Observed by A‐Train Satellites
Abstract Prolific winter (December‐January‐February) snowfall occurs over northwest Japan due to frequent sea‐effect precipitation that develops during cold‐air outbreaks over the Sea of Japan (SOJ). Knowledge of sea‐effect clouds and precipitation across the SOJ region has historically been constrained, however, by limited offshore in situ observations and remote‐sensing limitations. This paper uses sensors from National Aeronautics and Space Administration (NASA)'s A‐Train Satellite Constellation to examine winter sea‐effect properties in the SOJ region. The analysis shows that cloud and precipitation occurrence generally increases across the SOJ from Asia to Japan, as potential sea‐effect periods with an along‐orbit mean sea surface to 850‐hPa temperature difference ≥13 °C comprise a majority of the total clouds and precipitation. Sea‐effect clouds and precipitation occur most frequently in an arc‐shaped area that extends from the western SOJ, where the Japan‐Sea Polar‐Airmass Convergence Zone (JPCZ) is common, to the coast of Honshu, and then northward to Hokkaido. Radar, lidar, and column water path statistics along A‐Train orbital tracks show that sea‐effect precipitation is deepest along the central Honshu coast and becomes shallower but more frequent with northward extent. Precipitation amount and frequency maximize along the coast and adjacent mountains but decline with inland extent, most abruptly downstream of higher mountain barriers. This work illustrates that air‐sea interactions, coastal geometry, and regional topography strongly modulate cloud and precipitation patterns during sea‐effect periods in the SOJ region.
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- Award ID(s):
- 1635654
- PAR ID:
- 10374863
- Publisher / Repository:
- DOI PREFIX: 10.1029
- Date Published:
- Journal Name:
- Journal of Geophysical Research: Atmospheres
- Volume:
- 124
- Issue:
- 3
- ISSN:
- 2169-897X
- Page Range / eLocation ID:
- p. 1322-1335
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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