气候变化领域集成服务门户(CCPortal): Developing a drought-monitoring index for the contiguous US using SMAP

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DOI	10.5194/hess-22-6611-2018
	Developing a drought-monitoring index for the contiguous US using SMAP
	Sadri S.; Wood E.F.; Pan M.
发表日期	2018
ISSN	1027-5606
起始页码	6611
结束页码	6626
卷号	22 期号:12
英文摘要	Since April 2015, NASA's Soil Moisture Active Passive (SMAP) mission has monitored near-surface soil moisture, mapping the globe (between 85.044° N/S) using an L-band (1.4 GHz) microwave radiometer in 2-3 days depending on location. Of particular interest to SMAP-based agricultural applications is a monitoring product that assesses the SMAP near-surface soil moisture in terms of probability percentiles for dry and wet conditions. However, the short SMAP record length poses a statistical challenge for meaningful assessment of its indices. This study presents initial insights about using SMAP for monitoring drought and pluvial regions with a first application over the contiguous United States (CONUS). SMAP soil moisture data from April 2015 to December 2017 at both near-surface (5 cm) SPL3SMP, or Level 3, at ∼ 36 km resolution, and root-zone SPL4SMAU, or Level 4, at ∼ 9 km resolution, were fitted to beta distributions and were used to construct probability distributions for warm (May-October) and cold (November-April) seasons. To assess the data adequacy and have confidence in using short-term SMAP for a drought index estimate, we analyzed individual grids by defining two filters and a combination of them, which could separate the 5815 grids covering CONUS into passed and failed grids. The two filters were (1) the Kolmogorov-Smirnov (KS) test for beta-fitted long-term and the short-term variable infiltration capacity (VIC) land surface model (LSM) with 95% confidence and (2) good correlation (≥ 0:4) between beta-fitted VIC and beta-fitted SPL3SMP. To evaluate which filter is the best, we defined a mean distance (MD) metric, assuming a VIC index at 36 km resolution as the ground truth. For both warm and cold seasons, the union of the filters - which also gives the best coverage of the grids throughout CONUS - was chosen to be the most reliable filter. We visually compared our SMAP-based drought index maps with metrics such as the U.S. Drought Monitor (from D0-D4), 1-month Standard Precipitation Index (SPI) and near-surface VIC from Princeton University. The root-zone drought index maps were shown to be similar to those produced by the root-zone VIC, 3- month SPI, and the Gravity Recovery and Climate Experiment (GRACE). This study is a step forward towards building a national and international soil moisture monitoring system without which quantitative measures of drought and pluvial conditions will remain difficult to judge. © Author(s) 2018.
语种	英语
scopus关键词	Drought; Maps; Microwave devices; Microwave measurement; Moisture control; NASA; Passive filters; Soil moisture; Dry and wet conditions; Gravity recovery and climate experiments; Kolmogorov-Smirnov test; Microwave radiometers; Soil moisture active passive (SMAP); Soil moisture monitoring; Standard precipitation indices; Variable infiltration capacities; Probability distributions; drought; GRACE; index method; microwave radiometer; monitoring system; rhizosphere; soil moisture; New Jersey; Princeton [New Jersey]; United States; United States
来源期刊	Hydrology and Earth System Sciences
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/159815
作者单位	Sadri, S., Department of Civil and Environmental Engineering, Princeton University, 59 Olden St, Princeton, NJ 08540, United States; Wood, E.F., Department of Civil and Environmental Engineering, Princeton University, 59 Olden St, Princeton, NJ 08540, United States; Pan, M., Department of Civil and Environmental Engineering, Princeton University, 59 Olden St, Princeton, NJ 08540, United States
推荐引用方式 GB/T 7714	Sadri S.,Wood E.F.,Pan M.. Developing a drought-monitoring index for the contiguous US using SMAP[J],2018,22(12).
APA	Sadri S.,Wood E.F.,&Pan M..(2018).Developing a drought-monitoring index for the contiguous US using SMAP.Hydrology and Earth System Sciences,22(12).
MLA	Sadri S.,et al."Developing a drought-monitoring index for the contiguous US using SMAP".Hydrology and Earth System Sciences 22.12(2018).