Synergistic use of SMAP and OCO-2 data in assessing the responses of ecosystem productivity to the 2018 US drought

REMOTE SENSING OF ENVIRONMENT

卷:251

Article

Li, Xing¹  Xiao, Jingfeng¹  Kimball, John S.²  Reichle, Rolf H.³  Scott, Russell L.⁴  Litvak, Marcy E.⁵  Bohrer, Gil⁶  Frankenberg, Christian^7,8 

[1] Univ New Hampshire, Inst Study Earth Oceans & Space, Earth Syst Res Ctr, Durham, NH 03824 USA

[2] Univ Montana, Coll Forestry & Conservat, Numer Terradynam Simulat Grp, Missoula, MT 59812 USA

[3] NASA, Global Modeling & Assimilat Off, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA

[4] USDA ARS, Southwest Watershed Res Ctr, Tucson, AZ 85719 USA

[5] Univ New Mexico, Dept Biol, Albuquerque, NM 87131 USA

[6] Ohio State Univ, Dept Civil Environm & Geodet Engn, Columbus, OH 43210 USA

[7] CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA

[8] CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA

关键词: Soil Moisture Active Passive;    Orbiting Carbon Observatory-2;    GOSIF;    Soil moisture;    Sun-induced chlorophyll fluorescence;    Gross primary production;    Water stress;    Dryland;    Carbon cycle;    Crop yield;    Enhanced vegetation index;   

DOI  :  10.1016/j.rse.2020.112062

来源: Elsevier

【 摘 要 】

Soil moisture and gross primary productivity (GPP) estimates from the Soil Moisture Active Passive (SMAP) and solar-induced chlorophyll fluorescence (SIF) from the Orbiting Carbon Observatory-2 (OCO-2) provide new opportunities for understanding the relationship between soil moisture and terrestrial photosynthesis over large regions. Here we explored the potential of the synergistic use of SMAP and OCO-2 based data for monitoring the responses of ecosystem productivity to drought. We used complementary observational information on root-zone soil moisture and GPP (9 km) from SMAP and fine-resolution SIF (0.05 degrees; GOSIF) derived from OCO-2 SIF soundings. We compared the spatial pattern and temporal evolution of anomalies of these variables over the conterminous U.S. during the 2018 drought, and examined to what extent they could characterize the drought-induced variations of flux tower GPP and crop yield data. Our results showed that SMAP GPP and GOSIF, both freely available online, could well capture the spatial extent and dynamics of the impacts of drought indicated by the U.S. Drought Monitor maps and the SMAP root-zone soil moisture deficit. Over the U.S. Southwest, monthly anomalies of soil moisture showed significant positive correlations with those of SMAP GPP (R-2 = 0.44, p < 0.001) and GOSIF (R-2 = 0.76, p < 0.001), demonstrating strong water availability constraints on plant productivity across dryland ecosystems. We further found that SMAP GPP and GOSIF captured the impact of drought on tower GPP and crop yield. Our results suggest that synergistic use of SMAP and OCO-2 data products can reveal the drought evolution and its impact on ecosystem productivity and carbon uptake at multiple spatial and temporal scales, and demonstrate the value of SMAP and OCO-2 for studying ecosystem function, carbon cycling, and climate change.

【 授权许可】

Free