[O-11] Senior high school student poster presentations

[O11-P44] Why Shiranui is seen in Hachisaku - Explore from a meteorological point of view based on the conditions of occurrence of Shiranui.

*shoma murakami¹, naoto komeda¹, koki nishikawa¹, taiki yoshida¹, kouki tokumaru¹, mai horita¹, runa nishida¹, *naohiro hashimoto¹ (1.Kumamoto Prefectural Uto High School)

Keywords:mirage, sea water temperature, wind speed

We have been studying Shiranui for seven years now. Shiranui refers to the mirage
phenomenon seen in the Shiranui Sea during the first day of the eighth lunar
month, and this time we studied why it is seen during the first day of the eighth
lunar month from the meteorological viewpoints of temperature difference between
sea water and air temperature and slight wind in the line-of-sight direction.
The temperature difference between sea surface temperature and minimum air
temperature was investigated by measuring sea water temperature using a device of
my own making and by comparing it with sea surface temperature data. As a result,
it was found that the temperature difference between the left and right sides of
the sea surface exists, which is a condition for the occurrence of mirages in
summer and Hassaku. In addition, by focusing on wind speed, we investigated what
kind of winds were blowing in the coastal areas of the Shiranui Sea, and found
that weak winds often blow at night during the summer and Hassaku seasons. Based
on these two results, it is thought that the Shiranui is generated when the
temperature difference between the sea water temperature and the air temperature
is high enough to cause mirages during summer and Hassaku, and when a light breeze
in the direction of the summer line of sight blows there.