Sensitivity of summer precipitation in regional spectral model simulations over eastern China to physical schemes: Daily, extreme and diurnal cycle

2019 ◽  
Vol 39 (11) ◽  
pp. 4340-4357
Author(s):  
Peishu Zong ◽  
Yali Zhu ◽  
Jianping Tang
Keyword(s):  
Diurnal Cycle ◽  
Eastern China ◽  
Summer Precipitation ◽  
Spectral Model ◽  
Model Simulations ◽  
Regional Spectral Model

scholarly journals The Diurnal Cycle of Precipitation in Regional Spectral Model Simulations over West Africa: Sensitivities to Resolution and Cumulus Schemes

2015 ◽  
Vol 30 (2) ◽  
pp. 424-445 ◽  
Author(s):  
Xiaogang He ◽  
Hyungjun Kim ◽  
Pierre-Emmanuel Kirstetter ◽  
Kei Yoshimura ◽  
Eun-Chul Chang ◽  
...  
Keyword(s):  
West Africa ◽  
Diurnal Cycle ◽  
Climate Models ◽  
Monsoon Season ◽  
Single Layer ◽  
Spectral Model ◽  
Peak Time ◽  
Test Bed ◽  
Regional Spectral Model ◽  
Diurnal Cycle Of Precipitation

Abstract As a basic form of climate patterns, the diurnal cycle of precipitation (DCP) can provide a key test bed for model reliability and development. In this study, the DCP over West Africa was simulated by the National Centers for Environmental Prediction (NCEP) Regional Spectral Model (RSM) during the monsoon season (April–September) of 2005. Three convective parameterization schemes (CPSs), single-layer simplified Arakawa–Schubert (SAS), multilayer relaxed Arakawa–Schubert (RAS), and new Kain–Fritsch (KF2), were evaluated at two horizontal resolutions (20 and 10 km). The Benin mesoscale site was singled out for additional investigation of resolution effects. Harmonic analysis was used to characterize the phase and amplitude of the DCP. Compared to satellite observations, the overall spatial distributions of amplitude were well captured at regional scales. The RSM properly reproduced the observed late afternoon peak over land and the early morning peak over ocean. Nevertheless, the peak time was early. Sensitivity experiments of CPSs showed similar spatial patterns of rainfall totals among the schemes; CPSs mainly affected the amplitude of the diurnal cycle, while the phase was not significantly shifted. There is no clear optimal pairing of resolution and CPS. However, it is found that the sensitivity of DCP to CPSs and resolution varies with the partitioning between convective and stratiform, which implies that appropriate partitioning needs to be considered for future development of CPSs in global or regional climate models.

scholarly journals Simulation study on the indirect effect of sulfate on the summer climate over the eastern China monsoon region

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dongdong Wang ◽  
Bin Zhu ◽  
Hongbo Wang ◽  
Li Sun
Keyword(s):  
Radiative Forcing ◽  
Asian Summer Monsoon ◽  
Cloud Condensation Nuclei ◽  
Eastern China ◽  
Summer Precipitation ◽  
Cloud Droplet ◽  
Monsoon Region ◽  
Liquid Water Path ◽  
Surface Cooling ◽  
Community Atmosphere Model

AbstractIn this study, we designed a sensitivity test using the half number concentration of sulfate in the nucleation calculation process to study the aerosol-cloud interaction (ACI) of sulfate on clouds, precipitation, and monsoon intensity in the summer over the eastern China monsoon region (ECMR) with the National Center for Atmospheric Research Community Atmosphere Model version 5. Numerical experiments show that the ACI of sulfate led to an approximately 30% and 34% increase in the cloud condensation nuclei and cloud droplet number concentrations, respectively. Cloud droplet effective radius below 850 hPa decreased by approximately 4% in the southern ECMR, while the total liquid water path increased by 11%. The change in the indirect radiative forcing due to sulfate at the top of the atmosphere in the ECMR during summer was − 3.74 W·m−2. The decreased radiative forcing caused a surface cooling of 0.32 K and atmospheric cooling of approximately 0.3 K, as well as a 0.17 hPa increase in sea level pressure. These changes decreased the thermal difference between the land and sea and the gradient of the sea-land pressure, leading to a weakening in the East Asian summer monsoon (EASM) and a decrease in the total precipitation rate in the southern ECMR. The cloud lifetime effect has a relatively weaker contribution to summer precipitation, which is dominated by convection. The results show that the ACI of sulfate was one possible reason for the weakening of the EASM in the late 1970s.

scholarly journals Roles of anthropogenic forcings in the observed trend of decreasing late-summer precipitation over the East Asian transitional climate zone

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wei Zhao ◽  
Wen Chen ◽  
Shangfeng Chen ◽  
Hainan Gong ◽  
Tianjiao Ma
Keyword(s):  
Asian Summer Monsoon ◽  
Dominant Role ◽  
East Asian ◽  
Eastern China ◽  
Summer Precipitation ◽  
Late Summer ◽  
Water Vapor Transport ◽  
Anthropogenic Aerosol ◽  
Climate Zone ◽  
Drying Trend

AbstractObservations indicate that late-summer precipitation over the East Asian transitional climate zone (TCZ) showed a pronounced decreasing trend during 1951–2005. This study examines the relative contributions of anthropogenic [including anthropogenic aerosol (AA) and greenhouse gas (GHG)] and natural forcings to the drying trend of the East Asian TCZ based on simulations from CMIP5. The results indicate that AA forcing plays a dominant role in contributing to the drying trend of the TCZ. AA forcing weakens the East Asian summer monsoon via reducing the land-sea thermal contrast, which induces strong low-level northerly anomalies over eastern China, suppresses water vapor transport from southern oceans and results in drier conditions over the TCZ. In contrast, GHG forcing leads to a wetting trend in the TCZ by inducing southerly wind anomalies, thereby offsetting the effect of the AA forcing. Natural forcing has a weak impact on the drying trend of the TCZ due to the weak response of atmospheric anomalies.

scholarly journals Evaluation of Asian summer precipitation in different configurations of a high-resolution general circulation model in a range of decision-relevant spatial scales

2021 ◽  
Vol 25 (12) ◽  
pp. 6381-6405
Author(s):  
Mark R. Muetzelfeldt ◽  
Reinhard Schiemann ◽  
Andrew G. Turner ◽  
Nicholas P. Klingaman ◽  
Pier Luigi Vidale ◽  
...  
Keyword(s):  
High Resolution ◽  
Spatial Scale ◽  
Diurnal Cycle ◽  
General Circulation ◽  
Spatial Scales ◽  
Summer Precipitation ◽  
Physical Geography ◽  
Simulated Precipitation ◽  
The Mean ◽  
Precipitation Bias

Abstract. High-resolution general circulation models (GCMs) can provide new insights into the simulated distribution of global precipitation. We evaluate how summer precipitation is represented over Asia in global simulations with a grid length of 14 km. Three simulations were performed: one with a convection parametrization, one with convection represented explicitly by the model's dynamics, and a hybrid simulation with only shallow and mid-level convection parametrized. We evaluate the mean simulated precipitation and the diurnal cycle of the amount, frequency, and intensity of the precipitation against satellite observations of precipitation from the Climate Prediction Center morphing method (CMORPH). We also compare the high-resolution simulations with coarser simulations that use parametrized convection. The simulated and observed precipitation is averaged over spatial scales defined by the hydrological catchment basins; these provide a natural spatial scale for performing decision-relevant analysis that is tied to the underlying regional physical geography. By selecting basins of different sizes, we evaluate the simulations as a function of the spatial scale. A new BAsin-Scale Model Assessment ToolkIt (BASMATI) is described, which facilitates this analysis. We find that there are strong wet biases (locally up to 72 mm d−1 at small spatial scales) in the mean precipitation over mountainous regions such as the Himalayas. The explicit convection simulation worsens existing wet and dry biases compared to the parametrized convection simulation. When the analysis is performed at different basin scales, the precipitation bias decreases as the spatial scales increase for all the simulations; the lowest-resolution simulation has the smallest root mean squared error compared to CMORPH. In the simulations, a positive mean precipitation bias over China is primarily found to be due to too frequent precipitation for the parametrized convection simulation and too intense precipitation for the explicit convection simulation. The simulated diurnal cycle of precipitation is strongly affected by the representation of convection: parametrized convection produces a peak in precipitation too close to midday over land, whereas explicit convection produces a peak that is closer to the late afternoon peak seen in observations. At increasing spatial scale, the representation of the diurnal cycle in the explicit and hybrid convection simulations improves when compared to CMORPH; this is not true for any of the parametrized simulations. Some of the strengths and weaknesses of simulated precipitation in a high-resolution GCM are found: the diurnal cycle is improved at all spatial scales with convection parametrization disabled, the interaction of the flow with orography exacerbates existing biases for mean precipitation in the high-resolution simulations, and parametrized simulations produce similar diurnal cycles regardless of their resolution. The need for tuning the high-resolution simulations is made clear. Our approach for evaluating simulated precipitation across a range of scales is widely applicable to other GCMs.

scholarly journals Detectable Anthropogenic Influence on Changes in Summer Precipitation in China

2020 ◽  
Vol 33 (13) ◽  
pp. 5357-5369
Author(s):  
Chunhui Lu ◽  
Fraser C. Lott ◽  
Ying Sun ◽  
Peter A. Stott ◽  
Nikolaos Christidis
Keyword(s):  
Human Life ◽  
Eastern China ◽  
Precipitation Amount ◽  
Summer Precipitation ◽  
Heavy Precipitation ◽  
Observation Data ◽  
Anthropogenic Influence ◽  
Anthropogenic Forcing ◽  
The Future ◽  
Light Precipitation

AbstractIn China, summer precipitation contributes a major part of the total precipitation amount in a year and has major impacts on society and human life. Whether any changes in summer precipitation are affected by external forcing on the climate system is an important issue. In this study, an optimal fingerprinting method was used to compare the observed changes of total, heavy, moderate, and light precipitation in summer derived from newly homogenized observation data with the simulations from multiple climate models participating in phase 5 of the Coupled Model Intercomparison Project (CMIP5). The results demonstrate that the anthropogenic forcing signal can be detected and separated from the natural forcing signal in the observed increase of seasonal accumulated precipitation amount for heavy precipitation in summer in China and eastern China (EC). The simulated changes in heavy precipitation are generally consistent with observed change in China but are underestimated in EC. When the changes in precipitation of different intensities are considered simultaneously, the human influence on simultaneous changes in moderate and light precipitation can be detected in China and EC in summer. Changes attributable to anthropogenic forcing explain most of the observed regional changes for all categories of summer precipitation, and natural forcing contributes little. In the future, with increasing anthropogenic influence, the attribution-constrained projection suggests that heavy precipitation in summer will increase more than that from the model raw outputs. Society may therefore face a higher risk of heavy precipitation in the future.

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