气候变化领域集成服务门户(CCPortal): Evaluation and integration of the top-down and bottom-up satellite precipitation products over mainland China

CCPortal

DOI	10.1016/j.jhydrol.2019.124456
	Evaluation and integration of the top-down and bottom-up satellite precipitation products over mainland China
	Zhang, Ling; Li, Xin; Cao, Yanping; Nan, Zhuotong; Wang, Weizhen; Ge, Yingchun; Wang, Penglong; Yu, Wenjun
通讯作者	Zhang, L (通讯作者)
发表日期	2020
ISSN	0022-1694
EISSN	1879-2707
卷号	581
英文摘要	The satellite precipitation products (SPPs) obtained from the satellite soil moisture data through a bottom-up approach (i.e., the SM2RAIN algorithm) have been developed and released in recent years. However, the assessments and the integration of them with the conventional top-down SPPs remain absent over China. This study evaluated and integrated, for the first time, the bottom-up SM2RAIN-ASCAT (SM2RASC) product and the top-down Integrated Multi-satellite Retrievals for Global Precipitation Measurement (IMERG) Early Run product over mainland China. The evaluations were conducted at multiple temporal scales using both the continuous and categorical metrics; and the integration was implemented through a nudging scheme. Results indicate that IMERG outperforms SM2RASC in terms of CC at the daily scale. Meanwhile, it achieves a better performance than SM2RASC in detecting precipitation events. However, interestingly, IMERG performs worse than SM2RASC in terms of CC and NRMSE at the monthly scale. Both IMERG and SM2RASC show noticeable seasonal variability regarding the performance, with better qualities in the wet seasons than in the dry seasons. Spatially, IMERG performs better in the humid subregions than in the semi-arid subregions in terms of CC, while SM2RASC performs better in the semi-arid region than in the other subregions. Both of them perform relatively worse in the complex mountainous subregion (i.e. the Qinghai-Tibetan Plateau) and the arid subregion. The performances of the SPPs are closely correlated to the elevations and precipitation magnitudes. The correlations and their significances, however, vary between IMERG and SM2RASC, and between different time scales and different evaluation metrics. The integrated product could increase the median CC by up to 25.86% (or 7.23%), and reduce the median NRMSE by up to 14.72% (or 24.62%), at the daily (or monthly) scale in the validation period (i.e., 2012-2017), compared to the parent products. This study demonstrated the overall good performance of SM2RASC over mainland China, particularly in the semi-arid region, and meanwhile, highlighted the strong benefits of integrating the bottom-up and top-down SPPs.
关键词	SOIL-MOISTURE GPM IMERG RAINFALL PRODUCTS SYSTEM REGION TMPA EVAPOTRANSPIRATION SM2RAIN-CCI PERFORMANCE MICROWAVE
英文关键词	Satellite precipitation products; IMERG; SM2RAIN-ASCAT; Performance evaluation; Data integration; Mainland China
语种	英语
WOS研究方向	Engineering ; Geology ; Water Resources
WOS类目	Engineering, Civil ; Geosciences, Multidisciplinary ; Water Resources
WOS记录号	WOS:000514758300071
来源期刊	JOURNAL OF HYDROLOGY
来源机构	中国科学院青藏高原研究所
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/259962
推荐引用方式 GB/T 7714	Zhang, Ling,Li, Xin,Cao, Yanping,et al. Evaluation and integration of the top-down and bottom-up satellite precipitation products over mainland China[J]. 中国科学院青藏高原研究所,2020,581.
APA	Zhang, Ling.,Li, Xin.,Cao, Yanping.,Nan, Zhuotong.,Wang, Weizhen.,...&Yu, Wenjun.(2020).Evaluation and integration of the top-down and bottom-up satellite precipitation products over mainland China.JOURNAL OF HYDROLOGY,581.
MLA	Zhang, Ling,et al."Evaluation and integration of the top-down and bottom-up satellite precipitation products over mainland China".JOURNAL OF HYDROLOGY 581(2020).