Long-term changes in the rate of winter/spring snowfall at Hirosaki and the ice freezing duration of Lake Juhsan in Northern Japan

Abstract

In the official diary of Hirosaki Clan during 1705 -1860, daily weather conditions including the freeing and break-up dates of Lake Juhsan were described. We made an attempt at reconstructing winter/spring climates in each year at Hirosaki based on the freezing duration data of Lake Juhsan and the snowfall rates at Hirosaki. We also analyzed the relationship between the snowfall rates and winter/spring mean temperatures using meteorological data at JMA-AMeDAS Hirosaki, and high correlations between them were clarified.

Concerning winter/spring climate variations at Hirosaki, the 1740s and 1820s might have been warmer because of the decrease of ice freezing duration of Lake Juhsan and the rapid lowering of snowfall rates.