Decomposition of projected summer rainfall change over East Asia based on timeslice experiments

2021 ◽  
Author(s):  
Yu Huang ◽  
Hong-Li Ren ◽  
Robin Chadwick ◽  
Yi Deng
Keyword(s):  
East Asia ◽  
Summer Rainfall ◽  
Rainfall Change

scholarly journals Impacts of Late-Spring North Eurasian Soil Moisture Variation on Summer Rainfall Anomalies in Northern East Asia

2021 ◽  
Author(s):  
Yinghan Sang ◽  
Hong-Li Ren ◽  
Yi Deng ◽  
Xiaofeng Xu ◽  
Xueli Shi ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Temperature Gradient ◽  
East Asia ◽  
Summer Rainfall ◽  
Low Pressure ◽  
Late Spring ◽  
Boreal Summer ◽  
Pressure Center ◽  
North Eurasia ◽  
The Impact

Abstract This paper reports findings from a diagnostic and modeling analysis that investigates the impact of the late-spring soil moisture anomaly over North Eurasia on the boreal summer rainfall over northern East Asia (NEA). Soil moisture in May in the region from the Kara-Laptev Sea coasts to Central Siberian Plateau is found to be negatively correlated with the summer rainfall from Mongolia to Northeast China. The atmospheric circulation anomalies associated with the anomalously dry soil are characterized by a pressure dipole with the high-pressure center located over North Eurasia and the low-pressure center over NEA, where an anomalous lower-level moisture convergence occurs, favoring rainfall formation. Diagnoses and Modeling experiments demonstrate that the effect of the spring low soil moisture over North Eurasia may persist into the following summer through modulating local surface latent and sensible heat fluxes, increasing low-level air temperature at higher latitudes, and effectively reducing the meridional temperature gradient. The weakened temperature gradient could induce the decreased zonal wind and the generation of a low-pressure center over NEA, associated with a favorable condition of local synoptic activity. The above relationships and mechanisms are vice versa for the prior wetter soil and decreased NEA rainfall. These findings suggest that soil moisture anomalies over North Eurasia may act as a new precursor providing an additional predictability source for better predicting the summer rainfall in NEA.

scholarly journals Asymmetrical response of summer rainfall in East Asia to CO2 forcing

2021 ◽  
Author(s):  
Se-Yong Song ◽  
Sang-Wook Yeh ◽  
Soon-Il An ◽  
Jong-Seong Kug ◽  
Seung-Ki Min ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
East Asia ◽  
Cost Benefit Analysis ◽  
Cost Benefit ◽  
Summer Rainfall ◽  
Co2 Concentration ◽  
Sea Surface ◽  
Climate Conditions ◽  
Mitigation And Adaptation

Abstract Understanding the regional hydrological response to varying CO2 concentration is critical for cost-benefit analysis of mitigation and adaptation polices in the near future. To characterize summer monsoon rainfall change in East Asia due to a change in the CO2 pathway, we used the Community Earth System Model (CESM) with 28 ensemble members in which the CO2 concentration increases at a rate of 1% per year until its quadrupling peak, i.e., 1,468 ppm (ramp-up period), followed by a decrease of 1% per year until the present-day climate conditions, i.e., 367 ppm (ramp-down period). Although the CO2 concentration change is symmetric in time, the rainfall response is not symmetric. The amount of summer rainfall in East Asia is much larger during a ramp-down period than during a ramp-up period when the two periods of the same CO2 concentration are compared. This asymmetrical rainfall response is mainly due to an enhanced El Niño-like warming pattern as well as an increase in the meridional sea surface temperature gradient in the western North Pacific during a ramp-down period. These sea surface temperature patterns enhance the atmospheric teleconnections to East Asia and the local meridional circulations around East Asia, resulting in more rainfall over East Asia during the ramp-down period. This result implies that the removal of CO2 does not guarantee the return of regional rainfall to the previous climate state with the same CO2 concentration.

Assessing the internal variability in multi-decadal trends of summer rainfall over East Asia-Northwest Pacific with a large ensemble of GCM simulations

2020 ◽  
Author(s):  
Ruyu Gan
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
East Asia ◽  
Coupled Model ◽  
Summer Rainfall ◽  
Internal Variability ◽  
Sea Surface ◽  
Northwest Pacific ◽  
Model Intercomparison ◽  
Intercomparison Project

<p><span> models from phase 5 of the Coupled Model Intercomparison Project (CMIP5). </span><span>sea surface temperature</span></p>

Distinct Principal Modes of Early and Late Summer Rainfall Anomalies in East Asia*

2009 ◽  
Vol 22 (13) ◽  
pp. 3864-3875 ◽  
Author(s):  
Bin Wang ◽  
Jian Liu ◽  
Jing Yang ◽  
Tianjun Zhou ◽  
Zhiwei Wu
Keyword(s):  
East Asia ◽  
Summer Monsoon ◽  
Land Surface ◽  
Southern Oscillation ◽  
Southern China ◽  
Late Summer ◽  
Summer Rainfall ◽  
Seasonal Prediction ◽  
Early Summer ◽  
Rainfall Anomalies

Abstract The current seasonal prediction of East Asia (EA) summer monsoon deals with June–July–August (JJA) mean anomalies. This study shows that the EA summer monsoon may be divided into early summer [May–June (MJ)] and late summer [July–August (JA)] and exhibits remarkable differences in mean state between MJ and JA. This study reveals that the principal modes of interannual precipitation variability have distinct spatial and temporal structures during the early and late summer. These principal modes can be categorized as either El Niño–Southern Oscillation (ENSO) related or non-ENSO related. During the period of 1979–2007, ENSO-related modes explain 35% of MJ variance and 45% of JA variance, and non-ENSO-related modes account for 25% of MJ variance and 20% of JA variance. For ENSO-related variance, about two-thirds are associated with ENSO decaying phases, and one-third is associated with ENSO developing phases. The ENSO-related MJ modes generally concur with rapid decay or early development of ENSO episodes, and the opposite tends to apply to ENSO-related JA modes. The non-ENSO MJ mode is preceded by anomalous land surface temperatures over southern China during the previous March and April. The non-ENSO JA mode is preceded by lasting equatorial western Pacific (the Niño-4 region) warming from the previous winter through late summer. The results suggest that 1) prediction of bimonthly (MJ) and (JA) anomalies may be useful, 2) accurate prediction of the detailed evolution of ENSO is critical for prediction of ENSO-related bimonthly rainfall anomalies over East Asia, and 3) non-ENSO-related modes are of paramount importance during ENSO neutral years. Further establishment of the physical linkages between the non-ENSO modes and their corresponding precursors may provide additional sources for EA summer monsoon prediction.

scholarly journals Asymmetrical response of summer rainfall in east asia to CO2 forcing

2021 ◽  
Author(s):  
Se-Yong Song ◽  
Sang-Wook Yeh ◽  
Soon-Il An ◽  
Jong-Seong Kug ◽  
Seung-Ki Min ◽  
...  
Keyword(s):  
East Asia ◽  
Summer Rainfall ◽  
Co2 Forcing

scholarly journals Robust Nocturnal and Early Morning Summer Rainfall Peaks over Continental East Asia in a Global Multiscale Modeling Framework

Atmosphere ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 53 ◽  
Author(s):  
Yi Zhang ◽  
Haoming Chen ◽  
Dan Wang
Keyword(s):  
East Asia ◽  
Multiscale Modeling ◽  
Diurnal Cycle ◽  
Summer Rainfall ◽  
Early Morning ◽  
Atmospheric Modeling ◽  
The Tibetan Plateau ◽  
Moderate Increase ◽  
Modeling Framework ◽  
Multiscale Modeling Framework

The diurnal cycle of convection and precipitation is an important atmospheric feature. It also poses a great challenge to global numerical atmospheric modeling. Over continental East Asia, most global models cannot well capture the nocturnal and early morning peaks of summer rainfall. This problem may lead to dry biases and limit the modeling skills. This study investigates this problem using a global multiscale modeling framework (Super-Parameterized CAM5; SPCAM5). The nocturnal and early morning peaks, which are almost absent in CAM5 and a coarser-resolution SPCAM5, can be successfully captured by SPCAM5 with a moderate increase in the horizontal resolution. On the lee side of the Tibetan Plateau, SPCAM5 generates robust eastward propagating rainfall signals, which correspond to the moving convective systems, as revealed by the heating and drying profiles. Over the eastern plain of China, the early morning peaks become more evident, corresponding to a stratiform-type heating structure in the midlevel. A sensitivity experiment with altered grid-scale forcing also suggests the important preconditioning role of the vertical moisture advection in regulating the early morning peaks. These results highlight the added value of representing multiscale processes to the successful simulation of the diurnal cycle over continental East Asia.

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