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Variations of precipitation in tropical-subtropical regions are fundamentally important to human sustainable development. However, the dominant cyclicity and the mechanism of orbital-scale precipitation variations remain under extensive debate. Here, we used a newly drilled core from the Tianyang (TY) maar lake (South China) to reconstruct Asian monsoon precipitation variations over the past ~ 250,000 years, providing a new independent paleoprecipitation record for the core tropical monsoon region. The measured magnetic susceptibility and grain size records of TY maar lake reveal dominant precession and semiprecession cycles, evidencing the low-latitude insolation forcing on tropical monsoon precipitation variations. Feedbacks of Intertropical Convergence Zone shifts and orbital-scale El Niño/Southern Oscillation variations are suggested to play important roles in this forcing mechanism. Moreover, we detected correlation between the rainstorms and the tropical zonal sea surface temperature gradient during the moderate Marine Isotope Stage (MIS) 5a. This correspondence further confirms the effect of tropical internal feedbacks on orbital-scale precipitation variations. However, the glacial-interglacial cycle is weak in our record, indicating that the variability of Asian monsoon precipitation is likely modulated by certain other processes such as latitudinal effects and air-sea feedback. [ABSTRACT FROM AUTHOR]

We analyzed a large ensemble dataset called the database for Policy Decision Making for Future climate change (d4PDF), which contains 60-km resolution atmospheric general circulation model output and 20-km resolution dynamical downscaling for the Japanese domain. The increase in moisture and precipitation, and their global warming response in June–July–August were described focusing on the differences between Hokkaido and Kyushu; Hokkaido is cool and dry and Kyushu is hot and humid in the current climate. The results suggested that the specific humidity increased almost following the Clausius Clapeyron relation, but the change in stationary circulation suppressed the precipitation increase, except for in western Kyushu. The + 4 K climate in Hokkaido would be as hot and humid as the present climate in Kyushu. The circulation change related to the southward shift of the jet stream and an eastward shift of the Bonin high weakened the moisture flux convergence via a stationary field over central Japan including eastern Kyushu. The transient eddy activity counteracted the increase in humidity, so that the moisture flux convergence and precipitation did not change much over Hokkaido. Because the contribution of tropical cyclones to the total precipitation was at most 10%, the decrease in the number of tropical cyclones did not explain the predicted change in precipitation. [ABSTRACT FROM AUTHOR]