Using the original infrared digital data of GMS, we obtained the distribution of equivalent black body temperature of the land surface of Tohoku District in the cold summer in 1980 and examined the locality of rice-plant damage caused by cool air mass in that summer.
Obtained results are as follows:
1. There is a close relationship between the distribution of paddy rice index and the trajectory of cold maritime air mass, what we call “Yamase”, in the northern Tohoku District.
2. Inspection of the data derived from the extensive observations without discontinuity make clear the relation between the low temperature area caused by “Yamase” and the damaged area as well as the relation between the trajectory of “Yamase” and orographic features.
3. During the prevailing period of “Yamase”, the sensible heat supply from ground surface in daytime is too small to bring about the upward motion in cloud layer, while the increase in horizontal momentum is significant in the cloud layer.
4. It is confirmed that the clouds caused by “Yamase” attain the coastal region of the Sea of Japan crossing over the Oou Mountains. The accurate prediction of this phenomenon is likely to be of great importance so as to prevent the cold summer damage.
5. In the southern Tohoku District, cloud formation due to Baiu-front activity makes it insufficient to detect the low-level “Yamase” current using the data of the observation from space.
6. The data of vertical temperature profile radiometer are needed to analyze “Yamase” advecting in lower layer.
7. This is the first time for the area damaged owing to “Yamase” in cold summer to be investigated using the GMS data. Accumulation of the case studies like this will hopefully help us to make out more accurately what the relation between the damaged area and the trajectory of “Yamase” is all about.