A study on the relation between unusual weather in Japan and large-scale circulations
Regional and temporal variations of unusual weather and the climatological wetness index in the east Asia will be investigated in order to find the large-scale features of unusual weather in Japan and its relationship to the global circulation systems. The analysis will include the relationship to long-term changes of the Asian monsoon, the subtropical high, the Pacific decadal oscillations, and the ENSO.
Relation between typhoon tracks and large-scale circulations will be analyzed, and their long-term variations will be investigated using reanalysis data and a global climate model.
Adiabatic heating in the atmosphere using JRA-25 reanalysis data
In the summer of 1993 and 1994, Japan was suffered from extremely hot and cold
weather conditions respectively. These phenomena affected on various aspects
of socio-economics widely. Recently in 2003 and 2004 similar conditions
occurred again.
The figure shows vertical cross-section of adiabatic heating anomalies along
130E-140E from the average of 7 years(1991-1997). Very contrastive
anomalous pattern can been seen in the tropics and mid-latitudinal zone.
The adiabatic heating is important as a driving source in the atmospheric
circulation, and its variation is considered to be deeply related with the
occurrence of extreme weather phenomena. We are conducting a research
using the latest JRA-25 data towards understanding the mechanisms for such
extreme weather occurrence.
