11:25 AM - 11:40 AM
[AHW22-15] Factors controlling seasonal variation of stable isotopes in precipitation across Japan
Keywords:stable isotopes in precipitation, the Baiu rainy season, precipitation amount effect
Spatial distributions of observed δ18O in precipitation across Japan show clear latitude effect in spring, fall and winter seasons, but that did not show in summer season. And, observed monthly δ18O in precipitation of June were lower than those for adjacent months in 6 climate regions except Northern Japan region. As a result of the IsoRSM simulation, spatial distribution of monthly δ18O in water vapor across Japan from June to September ranged from -22 to -20 permil and did not show the latitude effect. In the Baiu rainy season of 2013, precipitation amount was high in regions south of the Northern Japan region. It is suggested that monthly δ18O in precipitation was depleted by the amount effect in these regions. On the other hand, monthly δ18O in precipitation from June to September show the temperature effect in the Northern Japan region.