Winter climate changes over East Asian region under RCP scenarios using East Asian winter monsoon indices

Abstract

that resemble the composite strong winter monsoon pattern are simulated more or less weakly in CMIP5 compared to the observation. However, the regressed fields of sea level pressure, surface air temperature, 500-hPa geopotential height, and 300-hPa zonal wind are well established with pattern correlations above 0.83 between CMIP5 and observation data. The differences between RCPs and Historical indicate strong warming, which increases with latitude, ranging from 1 to 5 °C under RCP4.5 and from 3 to 7 °C under RCP8.5 in the East Asian region. The anomalous southerly winds generally become stronger, implying weaker EAWMs in both scenarios. These features are also identified with fields regressed onto the indices in RCPs. The future projections reveal that the interannual variability of the indices will be maintained with an intensity similar to that of the present. The correlation between monsoon indices and Arctic Oscillation increases over time. On the other hand, the correlation between monsoon indices and North Atlantic Oscillation decreases.

Links Between the Coral δ13C Record of Primary Productivity Variations in the Northern South China Sea and the East Asian Winter Monsoon

“…The pre‐1920s increase and the post‐1920s decrease in our coral‐based PP record for the NSCS correspond to the strengthening and the weakening, respectively, of the EAWM during these periods. Studies based on coupled models have suggested that the EAWM may weaken in the future because of the reduction in the land‐sea thermal contrast under emissions‐driven global warming scenarios (Hong et al, ; Hori & Ueda, ; Hu et al, ). Therefore, the PP in the NSCS will likely decrease in the coming decades due to the projected weakening of the EAWM, and this decrease may significantly impact the marine ecosystem and the biogeochemical cycles in the NSCS.…”

“…because of the reduction in the land-sea thermal contrast under emissions-driven global warming scenarios (Hong et al, 2016;Hori & Ueda, 2006;Hu et al, 2000). Therefore, the PP in the NSCS will likely decrease in the coming decades due to the projected weakening of the EAWM, and this decrease may significantly impact the marine ecosystem and the biogeochemical cycles in the NSCS.…”

“…Coincidentally, the weakening of both the EAWM and the PP since the 1920s has corresponded to the onset/acceleration of global warming (Hansen et al, 2010;Jones et al, 1999). Global warming preferentially warms high-latitude continents relative to the oceans and, in turn, weakens both the land-sea thermal contrast and the land-sea pressure gradient, leading to the weakening of the EAWM (Hong et al, 2016;Hu et al, 2000). This weakening could result in a decrease in the PP in the NSCS by weakening the vertical mixing therein and limiting the amount of nutrients introduced into the euphotic zone (Behrenfeld et al, 2006;Falkowski et al, 1998;Liu et al, 2002Liu et al, , 2013.…”

The Asian Monsoon and its Future Change in Climate Models: A Review

“…Based on the surface meridional wind strength index, the ensemble mean of CMIP3 and CMIP5 models shows a weakening (strengthening) East Asian winter monsoon circulation north (south) of approximately 25°N, associated with the northward shift of the Aleutian Low, and decreased northwest-southeast thermal and sea level pressure differences across Northeast Asia (Jiang and Tian 2013). The CMIP5 MME projects significant intensification and a northward shift of the Aleutian Low, associated with strong warming over the high-latitude North Pacific owing to a reduction of sea ice in the Bering Sea and the Okhotsk Sea (Ogata et al 2014;Hong et al 2016;Xu et al 2016). A cyclonic circulation anomaly north of 40°N and an anticyclonic anomaly south of 40°N in the North Pacific are consistent with the positive trend of the AO.…”

Activity Characteristics of the East Asian Trough in CMIP5 Models

“…The performances of the models in the Coupled Model Intercomparison Project phase 5 (CMIP5) in simulating EAWM are better than those in CMIP3 [23]. The multimodel ensemble (MME) of CMIP5 models is able to reproduce the overall characteristics of EAWM very well [24,25], although the climatological strength of the EAT is overestimated by most of the models [23,24]. However, the performances of CMIP5 models in the variation of EAT are unclear.…”