气候变化领域集成服务门户(CCPortal): The impact of modified rate of precipitation conversion parameter in the convective parameterization scheme of operational weather forecast model (GFS T1534) over Indian summer monsoon region

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DOI	10.1016/j.atmosres.2020.105185
	The impact of modified rate of precipitation conversion parameter in the convective parameterization scheme of operational weather forecast model (GFS T1534) over Indian summer monsoon region
	Ganai M.; Tirkey S.; Krishna R.P.M.; Mukhopadhyay P.
发表日期	2021
ISSN	0169-8095
卷号	248
英文摘要	The performance of the present operational global forecast system (GFS) at T1534 (~12.5 km) horizontal resolution with modified fractional cloud condensate to precipitation conversion parameter in the revised simplified Arakawa-Schubert (RSAS) convection scheme is evaluated for the summer monsoon seasons of 2018 and 2019 over the Indian region. The modified parameter has the form of an exponentially decreasing function of temperature above the freezing level. In contrast, below the freezing level, it is constant and is similar to default conversion parameter. The results reveal that the GFS T1534 with modified conversion parameter (EXPT) shows better fidelity in forecasting the mean summer monsoon rainfall over the Indian subcontinent region as compared to default GFS T1534 (CTRL). The rainfall probability distribution function analysis indicates a notable improvement in forecasting moderate and heavier category rainfall in EXPT as compared to CTRL. The improved distribution of total rainfall is found to be contributed by the proper forecasting of convective and large-scale rainfall in EXPT. It is likely that the reduced rate of conversion of cloud condensate to convective precipitation above the freezing level leads to a reduction in the convective rainfall, which eventually increases the moisture in the upper level through detrainment and hence enhances the large-scale precipitation. Further, EXPT shows relative improvement in forecasting outgoing longwave radiation, wind circulation, cloud fraction, dynamical-thermodynamical processes, and moist-convective feedback through improved lower tropospheric moistening over the Indian region. Finally, various skill score analyses suggest that EXPT shows better skill in predicting moderate and heavier category rainfall with longer lead time over the Indian subcontinent region. Considering the large socioeconomic impact of heavy and extreme precipitation over India, the modified conversion parameter can be incorporated in the present operational GFS T1534 model. © 2020 Elsevier B.V.
英文关键词	Cloud condensate to precipitation conversion parameter; GFS T1534; Heavy rainfall; Indian summer monsoon
语种	英语
scopus关键词	Atmospheric thermodynamics; Distribution functions; Freezing; Rain; Convective parameterization schemes; Convective precipitation; Global forecast systems; Large-scale precipitation; Outgoing longwave radiation; Summer monsoon rainfall; Thermodynamical process; Weather forecast models; Weather forecasting; atmospheric convection; cloud condensation nucleus; monsoon; parameterization; precipitation intensity; weather forecasting; India
来源期刊	Atmospheric Research
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/141712
作者单位	Indian Institute of Tropical Meteorology, Ministry of Earth Sciences, Pune, India
推荐引用方式 GB/T 7714	Ganai M.,Tirkey S.,Krishna R.P.M.,et al. The impact of modified rate of precipitation conversion parameter in the convective parameterization scheme of operational weather forecast model (GFS T1534) over Indian summer monsoon region[J],2021,248.
APA	Ganai M.,Tirkey S.,Krishna R.P.M.,&Mukhopadhyay P..(2021).The impact of modified rate of precipitation conversion parameter in the convective parameterization scheme of operational weather forecast model (GFS T1534) over Indian summer monsoon region.Atmospheric Research,248.
MLA	Ganai M.,et al."The impact of modified rate of precipitation conversion parameter in the convective parameterization scheme of operational weather forecast model (GFS T1534) over Indian summer monsoon region".Atmospheric Research 248(2021).