Microphysical Properties of Marine Fog Retrieved from the Geostationary Satellites Himawari-8/9

The microphysical properties of fog off the southeast coast of Hokkaido and the east coast of the Sanriku region in Japan are estimated using data from the geostationary satellites Himawari-8/9. A retrieval algorithm for estimating cloud microphysical properties is applied to the Himawari-8/9 data, and an approach that calculates the cloud base height is introduced to distinguish between fog and low cloud. This approach captures 70% of the fog events reported at the Kushiro site in Hokkaido with 78% precision rate, 38% miss rate, and 29% overlook rate. Using this approach, 9 years of climatology for the optical thickness, effective radius, and liquid water path of fog are derived over the wide target areas. The estimated effective radius over the land agrees qualitatively with ground-based measurements of the microphysical properties of fog despite the limited availability of such data in the literature. The results also show that the microphysical properties of fog vary around the coastline between sea and land.