Summertime precipitation in Hokkaido and Kyushu, Japan in response to global warming

Abstract

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 20km 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. The results suggested that the speci c 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 ux convergence via a stationary eld over central Japan including eastern Kyushu. The transient eddy activity counteracted the increase in humidity, so that the moisture ux 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.

Assessing climate change risks associated with precipitation at unfavorable times in winter wheat using an improved crop calendar model incorporating vernalization and winter survival

“…Since the present analyses focused on Hokkaido, a region with abundant spring snowmelt and a rainy summer, we did not consider the limitation of water availability during the crop duration. Available evidence indicates that summer precipitation in this region is likely to increase (Takabatake and Inatsu 2022), suggesting that the water availability would not be a limiting factor.…”

“…The humid conditions have historically caused significant yield reductions in this region (Shimoda et al 2022). Furthermore, because climate models have suggested an increase in summer precipitation in this region (Takabatake and Inatsu 2022), risks associated with summer precipitation should be seriously considered to ensure wheat production in this region. Climate projections have suggested intensified precipitation worldwide (Masson-Delmotte et al 2021), implying that there is an increased likelihood for wheat farmers to be adversely affected by precipitation occurring at unfavorable times.…”

Spatial-temporal variations of extreme precipitation indices and their linkage with atmospheric circulation in the middle and lower reaches of the Yangtze River

“…Meanwhile, the mass divergence occurs to the south of the EAJ axis also contributes to the maintenance of upward motion. When the strong divergence outflow at high altitude coupled with strong convergence inflow at low altitude is not only conducive to the formation of potential instability (Wang et al, 2018;Wang and Zuo, 2016), but also benefits to lift the water vapor carried by the upper-low jet so as to release potentially unstable energy and form heavy precipitation (Jean et al, 1993;Joseph et al, 2015;Takabatake and Inatsu, 2021).…”

Projected changes in field workability of agricultural machinery operations for upland crop production in +4 K Hokkaido, Japan

“…While potential risks in the use of agricultural machines were suggested, negative changes in numbers of the total workdays and the consecutive unworkable days were quite small (< 1 d per month) and hence negligible in the present study domain without changes in the agricultural calendar (see also the following section). Although 4-K warming was projected to induce an increase in specific humidity by ~ 35 % in summertime Hokkaido, the projected increase in precipitation was smaller than this level due to changes in patterns of synoptic circulation phenomena around Japan (Takabatake and Inatsu, 2021). Takabatake and Inatsu (2021) reported that summertime precipitation under +4 K climate decreased by 10-20 % almost over central Japan but increased in western Kyushu (southern-and westernmost of the main islands of Japan) by 20-30 %.…”

“…Although 4-K warming was projected to induce an increase in specific humidity by ~ 35 % in summertime Hokkaido, the projected increase in precipitation was smaller than this level due to changes in patterns of synoptic circulation phenomena around Japan (Takabatake and Inatsu, 2021). Takabatake and Inatsu (2021) reported that summertime precipitation under +4 K climate decreased by 10-20 % almost over central Japan but increased in western Kyushu (southern-and westernmost of the main islands of Japan) by 20-30 %. The meteorological constraints on the use of agricultural machines during summertime may not be significant in most Japanese regions including the main island and Hokkaido but can be severe in western Kyushu.…”