Ocean around Japan is well known as the precipitation zone of the winter
monsoon. In this region, the change of the surface pressure pattern
causes large changes of precipitation and cloud distributions. However,
vertical structures for each type of precipitation systems have not yet
been well studied, especially over the Pacific Ocean.
The characteristics of winter precipitation systems over the north western
Pacific are analyzed using multiple sensors data onboard the TRMM satellite
during December-January-February of 1999/2000-2003/2004. By the PR and
VIRS, vertical and horizontal distribution of precipitation is investigated.
Winter precipitation patterns are classified into four types with the cloud
and pressure pattern and the region: the extratropical cyclone and front
pattern (CF) and the cold outbreak patten (CO) over the Sea of Japan (CO-J),
over the Yellow Sea (CO-Y) and over the Pacific Ocean (CO-P). For CO, the
height of precipitation is centered around 2 km and the shallow, isolated
and weak (< 20 dBZ) precipitation dominates. Cloud top height reaches
about 4 km. Compared with CO-Y and CO-J, CO-P tends to develop larger systems
and to have melting layers near the surface. For CF, the height of precipitation
is concentrated around 3 km and precipitation is relatively broad with
large variation of intensity.
Over the Japan Sea and the Pacific Ocean, most of the moisture for the
precipitation of the cold outbreaks is supplied from the sea surface,
though the contributions of latent heat flux over the two regions are
different. On the other hand, the precipitation around the low and front
is caused by the moisture supply from the surrounding regions.
References
Yamamoto Master thesis & Doctor thesis
