Changes of Hydroclimatic Intensity over East Asia Projected by Multiregional Climate Model Ensemble under RCP Scenarios.

This study assesses the hydroclimatic response toglobal warming over East Asia from multi-model ensembleregional projections. Four different regional climate models(RCMs), namely, WRF, HadGEM3-RA, RegCM4, andGRIMs, are used for dynamical downscaling of the HadleyCentre Global Environmental Model version 2–Atmosphereand Ocean (HadGEM2-AO) global projections forced by therepresentative concentration pathway (RCP4.5 and RCP8.5)scenarios. Annual mean precipitation, hydroclimatic intensityindex (HY-INT), and wet and dry extreme indices are analyzedto identify the robust behavior of hydroclimatic changein response to enhanced emission scenarios using highresolution(12.5 km) and long-term (1981–2100) daily precipitation.Ensemble projections exhibit increased hydroclimaticintensity across the entire domain and under both the RCPscenarios. However, a geographical pattern with predominantlyintensified HY-INT does not fully emerge in the mean precipitationchange because HY-INTis tied to the changes in theprecipitation characteristics rather than to those in the precipitationamount. All projections show an enhancement of highintensity precipitation and a reduction of weak intensity precipitation,which lead to a possible shift in hydroclimatic regimeprone to an increase of both wet and dry extremes. Ingeneral, projections forced by the RCP8.5 scenario tend toproduce a much stronger response than do those by theRCP4.5 scenario. However, the temperature increase underthe RCP4.5 scenario is sufficiently large to induce significantchanges in hydroclimatic intensity, despite the relatively uncertainchange in mean precipitation. Likewise, the forcedresponses of HY-INT and the two extreme indices are morerobust than that of mean precipitation, in terms of the statisticalsignificance and model agreement.

Acknowledgements

This work was carried out with the support of "Cooperative Research Program for Agriculture Science & Technology Development (Project No. PJ012293)" Rural Development Administration, Republic of Korea.

Reference

Imet al.,2017.Robust intensification of hydroclimatic intensity over East Asiafrom multi-model ensemble regional projections,TheorApplClimatol.