scholarly journals Convection-permitting regional climate simulation of warm-season precipitation over Eastern China

2019 ◽  
Vol 54 (3-4) ◽  
pp. 1469-1489 ◽  
Author(s):  
Yuxing Yun ◽  
Changhai Liu ◽  
Yali Luo ◽  
Xudong Liang ◽  
Ling Huang ◽  
...  
Keyword(s):  
East Asia ◽  
Regional Climate ◽  
Eastern China ◽  
Precipitation Amount ◽  
Wrf Model ◽  
Warm Season ◽  
Climate Simulation ◽  
The Tibetan Plateau ◽  
Model Skill ◽  
Geographical Regions

AbstractConvection-permitting regional climate models have been shown to improve precipitation simulation in many aspects, such as the diurnal cycle, precipitation frequency, intensity and extremes in many studies over several geographical regions of the world, but their skill in reproducing the warm-season precipitation characteristics over the East Asia has not been robustly tested yet. Motivated by recent advances in computing power, model physics and high-resolution reanalysis, we use the convection-permitting weather research and forecasting (WRF) model configured with 3 km grid spacing to simulate the warm-season precipitation in eastern China for 10 seasons (2008–2017). The hourly 31-km-resolution ERA5 reanalysis data are used to provide initial and boundary conditions for the simulations. The objectives are (1) to evaluate the model skill in simulating warm-season precipitation climatology in the East Asian monsoon region, (2) to identify the promises and problems of the convection-permitting simulation, and (3) to investigate solutions for the model deficiencies. Results demonstrate that the 3-km-resolution WRF model reasonably reproduces the spatial characteristics of seasonal and sub-seasonal precipitation, the seasonal meridional migration associated with the summer monsoon activity, the diurnal variation phase and amplitude, and the propagating convection east of the Tibetan Plateau. The major deficiency is that the model overestimates precipitation amount, especially in the afternoon. Analysis and sensitivity experiments suggest that improved treatment of sub-grid cloud fraction and the aerosol effects may help to suppress the oft-reported high precipitation bias. These results provide useful guidance for improving the model skill at simulating warm-season precipitation in East Asia.

scholarly journals Convection-Permitting Regional Climate Simulations Over Tibetan Plateau: Re-Initialization Versus Spectral Nudging

2021 ◽  
Author(s):  
Mengnan Ma ◽  
Pinhong Hui ◽  
Dongqing Liu ◽  
Peifeng Zhou ◽  
Jianping Tang
Keyword(s):  
Tibetan Plateau ◽  
Regional Climate ◽  
Wrf Model ◽  
Surface Air Temperature ◽  
Moisture Flux ◽  
Early Morning ◽  
Climate Simulation ◽  
Cold Bias ◽  
The Tibetan Plateau ◽  
Spectral Nudging

Abstract Two regional climate simulation experiments (spectral nudging and re-initialization) at convection-permitting scale are conducted using the WRF model over the Tibetan Plateau (TP). The surface air temperature (T2m) and the precipitation in summer during 2016–2018 are evaluated against the in-situ station observations and the Global Satellite Mapping of Precipitation (GSMaP) dataset. The results show that both experiments can successfully capture the spatial distribution and the daily variation of T2m and precipitation, with reasonable cold bias for temperature, dry bias for precipitation when compared with the station observations. In addition, the diurnal cycle of precipitation is investigated, indicating that both experiments tend to simulate the afternoon precipitation in advance and postpone the night precipitation. The precipitation bias is reduced by using the spectral nudging technique, especially at night and early morning. Possible causes for the differences between the two experiments are also analyzed. The daytime surface net radiation contributes a lot to the cold biases in the re-initialization experiment, and the stronger low-level moisture flux convergence leads to the wet biases. These results can provide valuable guidance for further fine-scale simulation studies over the TP.

scholarly journals Enriched East Asian oxygen isotope of precipitation indicates reduced summer seasonality in regional climate and westerlies

2020 ◽  
Vol 117 (26) ◽  
pp. 14745-14750 ◽  
Author(s):  
John C. H. Chiang ◽  
Michael J. Herman ◽  
Kei Yoshimura ◽  
Inez Y. Fung
Keyword(s):  
East Asia ◽  
Oxygen Isotope ◽  
Large Scale ◽  
Interannual Variation ◽  
Regional Climate ◽  
East Asian ◽  
Precipitation Amount ◽  
The Tibetan Plateau ◽  
Proximate Cause ◽  
Upper Level

Speleothem oxygen isotope records over East Asia reveal apparently large and rapid paleoclimate changes over the last several hundred thousand years. However, what the isotopic variation actually represent in terms of the regional climate and circulation is debated. We present an answer that emerges from an analysis of the interannual variation in amount-weighted annual δ18O of precipitation over East Asia as simulated by an isotope-enabled model constrained by large-scale atmospheric reanalysis fields.18O-enriched years have reduced summer seasonality both in terms of precipitation isotopes and in the large-scale circulation. Changes occur between June and October, where the δ18O of precipitation (δ18Op) transitions from the isotopically heavier winter to the lighter summer regime. For18O-enriched years, this transition is less pronounced. Variations in precipitation amount alone are insufficient to explain the amount-weighted annual δ18Opbetween18O-enriched and18O-depleted years. Reduced summer seasonality is also expressed in the low-level monsoonal southerlies and upper-level westerlies; for the latter, the northward migration across the Tibetan Plateau in the summer is less pronounced. Our result thus implicates the westerlies across the plateau as the proximate cause of East Asian paleomonsoon changes, manifested as a modulation of its summer peak.

scholarly journals Correction to: Convection-permitting regional climate simulation of warm-season precipitation over Eastern China

2020 ◽  
Vol 54 (5-6) ◽  
pp. 3227-3227
Author(s):  
Yuxing Yun ◽  
Changhai Liu ◽  
Yali Luo ◽  
Xudong Liang ◽  
Ling Huang ◽  
...  
Keyword(s):  
Regional Climate ◽  
Eastern China ◽  
Warm Season ◽  
Climate Simulation ◽  
Regional Climate Simulation

scholarly journals Observed Changes of Rain-Season Precipitation in China from 1960 to 2018

2021 ◽  
Vol 18 (19) ◽  
pp. 10031
Author(s):  
Yanyu Zhang ◽  
Shuying Zang ◽  
Xiangjin Shen ◽  
Gaohua Fan
Keyword(s):  
Climate Change ◽  
Global Climate ◽  
Regional Climate ◽  
Precipitation Amount ◽  
Heavy Precipitation ◽  
Central China ◽  
The Tibetan Plateau ◽  
Natural Ecosystems ◽  
Daily Precipitation Data ◽  
Rain Season

Precipitation during the main rain season is important for natural ecosystems and human activities. In this study, according to daily precipitation data from 515 weather stations in China, we analyzed the spatiotemporal variation of rain-season (May–September) precipitation in China from 1960 to 2018. The results showed that rain-season precipitation decreased over China from 1960 to 2018. Rain-season heavy (25 ≤ p < 50 mm/day) and very heavy (p ≥ 50 mm/day) precipitation showed increasing trends, while rain-season moderate (10 ≤ p < 25 mm/day) and light (0.1 ≤ p < 10 mm/day) precipitation showed decreasing trends from 1960 to 2018. The temporal changes of precipitation indicated that rain-season light and moderate precipitation displayed downward trends in China from 1980 to 2010 and rain-season heavy and very heavy precipitation showed fluctuant variation from 1960 to 2018. Changes of rain-season precipitation showed clear regional differences. Northwest China and the Tibetan Plateau showed the largest positive trends of precipitation amount and days. In contrast, negative trends were found for almost all precipitation grades in North China Plain, Northeast China, and North Central China. Changes toward drier conditions in these regions probably had a severe impact on agricultural production. In East China, Southeast China and Southwest China, heavy and very heavy precipitation had increased while light and moderate precipitation had decreased. This result implied an increasing risk of flood and mudslides in these regions. The advance in understanding of precipitation change in China will contribute to exactly predict the regional climate change under the background of global climate change.

Impact of spectral nudging on regional climate simulation over CORDEX East Asia using WRF

2016 ◽  
Vol 48 (7-8) ◽  
pp. 2339-2357 ◽  
Author(s):  
Jianping Tang ◽  
Shuyu Wang ◽  
Xiaorui Niu ◽  
Pinhong Hui ◽  
Peishu Zong ◽  
...  
Keyword(s):  
East Asia ◽  
Regional Climate ◽  
Climate Simulation ◽  
Regional Climate Simulation ◽  
Spectral Nudging ◽  
Cordex East Asia

Operational Precipitation Forecast Over China Using the Weather Research and Forecasting (WRF) Model at a Gray-Zone Resolution: Impact of Convection Parameterization

2021 ◽  
Author(s):  
XU ZHANG ◽  
YUHUA YANG ◽  
BAODE CHEN ◽  
WEI HUANG
Keyword(s):  
Case Studies ◽  
Southern China ◽  
Wrf Model ◽  
Warm Season ◽  
Precipitation Forecast ◽  
Weather Research And Forecasting ◽  
Operational System ◽  
Quantitative Precipitation Forecast ◽  
Geographical Regions ◽  
Convection Parameterization

AbstractThe quantitative precipitation forecast in the 9 km operational modeling system (without the use of a convection parameterization scheme) at the Shanghai Meteorological Service (SMS) usually suffers from excessive precipitation at the grid scale and less-structured precipitation patterns. Two scale-aware convection parameterizations were tested in the operational system to mitigate these deficiencies. Their impacts on the warm-season precipitation forecast over China were analyzed in case studies and two-month retrospective forecasts. The results from case studies show that the importance of convection parameterization depends on geographical regions and weather regimes. Considering a proper magnitude of parameterized convection can produce more realistic precipitation distribution and reduce excessive grid-scale precipitation in southern China. In the northeast and southwest China, however, the convection parameterization plays an insignificant role in precipitation forecast because of strong synoptic-scale forcing. A statistical evaluation of the two-month retrospective forecasts indicates that the forecast skill for precipitation in the 9-km operational system is improved by choosing proper convection parameterization. This study suggests that improvement in contemporary convection parameterizations is needed for their usage for various meteorological conditions and reasonable partitioning between parameterized and resolved convection.

scholarly journals Multidecadal Evaluation of WRF Downscaling Capabilities over Western Australia in Simulating Rainfall and Temperature Extremes

2015 ◽  
Vol 54 (2) ◽  
pp. 370-394 ◽  
Author(s):  
Julia Andrys ◽  
Thomas J. Lyons ◽  
Jatin Kala
Keyword(s):  
High Resolution ◽  
Western Australia ◽  
General Circulation ◽  
Regional Climate ◽  
Wrf Model ◽  
Climate Extremes ◽  
Convective Precipitation ◽  
Climate Simulation ◽  
Climate Indices ◽  
Climate Simulations

AbstractThe authors evaluate a 30-yr (1981–2010) Weather Research and Forecast (WRF) Model regional climate simulation over the southwest of Western Australia (SWWA), a region with a Mediterranean climate, using ERA-Interim boundary conditions. The analysis assesses the spatial and temporal characteristics of climate extremes, using a selection of climate indices, with an emphasis on metrics that are relevant for forestry and agricultural applications. Two nested domains at 10- and 5-km resolution are examined, with the higher-resolution simulation resolving convection explicitly. Simulation results are compared with a high-resolution, gridded observational dataset that provides daily rainfall, minimum temperatures, and maximum temperatures. Results show that, at both resolutions, the model is able to simulate the daily, seasonal, and annual variation of temperature and precipitation well, including extreme events. The higher-resolution domain displayed significant performance gains in simulating dry-season convective precipitation, rainfall around complex terrain, and the spatial distribution of frost conditions. The high-resolution domain was, however, influenced by grid-edge effects in the southwestern margin, which reduced the ability of the domain to represent frontal rainfall along the coastal region. On the basis of these results, the authors feel confident in using the WRF Model for regional climate simulations for the SWWA, including studies that focus on the spatial and temporal representation of climate extremes. This study provides a baseline climatological description at a high resolution that can be used for impact studies and will also provide a benchmark for climate simulations driven by general circulation models.

scholarly journals A Regional Climate Simulation Study Using WRF-ARW Model over Europe and Evaluation for Extreme Temperature Weather Events

2014 ◽  
Vol 2014 ◽  
pp. 1-22 ◽  
Author(s):  
Hari Prasad Dasari ◽  
Rui Salgado ◽  
Joao Perdigao ◽  
Venkata Srinivas Challa
Keyword(s):  
Land Surface ◽  
Heat Waves ◽  
Regional Climate ◽  
Extreme Temperature ◽  
Wrf Model ◽  
Initial Boundary ◽  
Analysis Data ◽  
Climate Simulation ◽  
Cold Wave ◽  
Local Climate

In this study regional climate simulations of Europe over the 60-year period (1950–2010) made using a 25 km resolution WRF model with NCEP 2.5 degree analysis for initial/boundary conditions are presented for air temperature and extreme events of heat and cold waves. The E-OBS 25 km analysis data sets are used for model validation. Results suggest that WRF could simulate the temperature trends (mean, maximum, minimum, seasonal maximum, and minimum) over most parts of Europe except over Iberian Peninsula, Mediterranean, and coastal regions. Model could simulate the slight fall of temperatures from 1950 to 1970 as well as steady rise in temperatures from 1970 to 2010 over Europe. Simulations show occurrence of about 80% of the total heat waves in the period 1970–2010 with maximum number of heat/cold wave episodes over Eastern and Central Europe in good agreement with observations. Relatively poor correlations and high bias are found for heat/cold wave episodes over the complex topographic areas of Iberia and Mediterranean regions where land surface processes play important role in local climate. The poor simulation of temperatures over the above regions could be due to deficiencies in representation of topography and surface physics which need further sensitivity studies.

Modeling the Effects of Lakes in the Tibetan Plateau on Diurnal Variations of Regional Climate and Their Seasonality

2020 ◽  
Vol 21 (11) ◽  
pp. 2523-2536
Author(s):  
Lingjing Zhu ◽  
Jiming Jin ◽  
Yimin Liu
Keyword(s):  
Tibetan Plateau ◽  
Regional Climate ◽  
Wrf Model ◽  
Surface Air Temperature ◽  
Diurnal Variations ◽  
The Tibetan Plateau ◽  
Near Surface ◽  
Local Climate ◽  
Lake Model ◽  
Physically Based

AbstractIn this study, we investigated the effects of lakes in the Tibetan Plateau (TP) on diurnal variations of local climate and their seasonal changes by using the Weather Research and Forecasting (WRF) Model coupled with a one-dimensional physically based lake model. We conducted WRF simulations for the TP over 2000–10, and the model showed excellent performance in simulating near-surface air temperature, precipitation, lake surface temperature, and lake-region precipitation when compared to observations. We carried out additional WRF simulations where all the TP lakes were replaced with the nearest land-use types. The differences between these two sets of simulations were analyzed to quantify the effects of the TP lakes on the local climate. Our results indicate that the strongest lake-induced cooling occurred during the spring daytime, while the most significant warming occurred during the fall nighttime. The cooling and warming effects of the lakes further inhibited precipitation during summer afternoons and evenings and motivated it during fall early mornings, respectively. This study lays a solid foundation for further exploration of the role of TP lakes in climate systems at different time scales.

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