Influence of the local sea surface temperature (SST) on snowfall in Pacific Ocean side of central Japan
Abstract
This study shows evidence that warm SST anomalies in mid - latitude s activate snowfall events in the areas where it seldom snow s climat ically .
Plain a reas facing the Sea of Japan side of Japan are known to be the one of the heav iest snowfall district s in the world . Prevailing cold and strong northwesterly winds due to the wintertime East Asian winter monsoon blows there almost every day in winter. The Sea of Japan, wh ose climatological SST is much warmer than t hose of the winter monsoon, provides air mass es over the Sea of Japan with a large amount of water vapor. T his also activate s convective snow cloud s over the Sea of Japan, and then many packets of the clouds repeatedly lands in the plain facing the Se a of Japan. This is why the plain areas facing the Sea of Japan side of Japan is famous for the heavy snowfall , and the snowfall events are "usual" there . On the contrary , on the Pacific Ocean side of Japan, the snow clouds are blocked by high mountain ranges lying in the center of Japan paralle l to the Japan A rchipelago. Because of the blockage of the mountain ranges, the Pacific side usually in fine and dry weather in winter. T he mountain ranges divide the winter climate of Japan. However, snowfall events in some areas on the Pacific side occasionally occur in association with winter monsoon , but still the snowfall is an "unusual" event there . Previous studies showed that the conditions that anomalously strong northwesterly winds with anomalously cold upper air temperature are important for the occurrence of the snowfall in these areas . T hese studies did not take account of the local oceanic influence, nor were they based on a statistical study. Present study statistically investigates influence of the SST of the Sea of Japan upon the heavy snowfall in the "unusual" area.Data analyses showed that northwesterly strong winds and low air temperature are significantly important factors for the heavy snowfall. Additionally, positive SSTs and anomalous upward heat and moisture fluxes over a part of the Sea of Japan are significantly important . Upward heat and moisture flux anomalies provide with a large amount of water vapor from the sea to the atmosphere, leading to enormous snowfall. We concludes that SST-enhanced anomalous ly strong convective clouds are able to cross the high mountain ranges .- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.A41O2799M
- Keywords:
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- 3305 Climate change and variability;
- ATMOSPHERIC PROCESSES;
- 3319 General circulation;
- ATMOSPHERIC PROCESSES;
- 3349 Polar meteorology;
- ATMOSPHERIC PROCESSES;
- 1621 Cryospheric change;
- GLOBAL CHANGE