Evaluating impacts of snow, surface water, soil and vegetation on empirical vegetation and snow indices for the Utqiaġvik tundra ecosystem in Alaska with the LVS3 model
| dc.contributor.author | Zhang, Qingyuan | |
| dc.contributor.author | Yao, Tian | |
| dc.contributor.author | Huemmrich, Karl | |
| dc.contributor.author | Middleton, Elizabeth M. | |
| dc.contributor.author | Lyapustin, Alexei | |
| dc.contributor.author | Wang, Yujie | |
| dc.date.accessioned | 2022-09-29T15:41:40Z | |
| dc.date.available | 2022-09-29T15:41:40Z | |
| dc.date.issued | 2020-02-04 | |
| dc.description.abstract | Satellite observations for the Arctic and boreal region may contain information of vegetation, soil, snow, snowmelt, and/or other surface water bodies. We investigated the impacts of vegetation, soil, snow and surface water on empirical vegetation/snow indices on a tundra ecosystem area located around Utqiaġvik (formerly Barrow) of Alaska with the Moderate Resolution Imaging Spectrometer (MODIS) images in 2001–2014. Empirical vegetation indices, such as normalized difference vegetation index (NDVI), enhanced vegetation index (EVI), the index of near infrared of vegetation (NIRv), and modified EVI (EVI2), have been used to monitor vegetation. Normalized difference snow index (NDSI) has been widely applied to monitor snow. The vegetation cover fraction (VGCF), the soil cover fraction (SOILCF), the snow cover fraction (SNOWCF), the surface water body cover fraction (WaterBodyCF), the fractional absorption of photosynthetically active radiation (PAR) by vegetation chlorophyll (fAPARchl), the fractional absorption of PAR by non-chlorophyll components of the vegetation (fAPARnon-chl), and the fractional absorption of PAR by the entire canopy (fAPARcanopy) are retrieved with the MODIS images and a coupled Leaf-Vegetation-Soil-Snow-Surface water body radiative transfer model, LVS3. The vegetation indices (NDVI, EVI, EVI2 and NIRv) differ from VGCF, fAPARchl, fAPARnon-chl, and fAPARcanopy. In addition to vegetation, we find that soil, snow and surface water also have impacts on vegetation indices NDVI, EVI (EVI2), and NIRv. Presence of snow makes lower the observed values of NDVI, EVI2 and NIRv. After snowmelt is gone, the vegetation indices (NDVI, EVI, EVI2 and NIRv) linearly decrease with SOILCF and WaterBodyCF, and WaterBodyCF has stronger impacts on these vegetation indices than SOILCF. The relationship between EVI and snow is complicated. NDSI non-linearly increases with SNOWCF, but linearly increases with sum of SNOWCF and WaterBodyCF (sum = 0.5893 × NDSI +0.4342, R2 = 0.976). NDSI linearly decreases with VGCF, and the relationship between NDSI and SOILCF is complex. Retrievals of VGCF, fAPARchl, fAPARnonchl and fAPARcanopy with the LVS3 model provide alternatives for vegetation monitoring and ecological modeling. | en_US |
| dc.description.sponsorship | We thank two anonymous reviewers for their constructive comments and suggestions on the earlier version of the manuscript. We also thank Dr. Maosheng Zhao for providing suggestions of relationship between PAR and downwelling shortwave radiation. This work was partially funded by the NASA Terrestrial Ecology Program (Grant # NNX12AJ51G, PI: Q. Zhang) and the Science of Terra and Aqua Program (Grant # NNX14AK50G, PI: Q. Zhang). K. F. Huemmrich was supported by ABoVE project grants NNX15AT78A and NNX17AC58A. This study was also partially supported by two NASA Headquarters sponsored programs (PI: E. Middleton), the Earth Observing One (EO-1) Mission Science Office (Sponsor, Dr. Garik Gutman) and the Surface Biology and Geology (SBG) science support project at the Goddard Space Flight Center (NASA/GSFC) through Mr. William (Woody) Turner. Computational support and resources were provided by the NASA Center for Climate Simulation (NCCS) at Goddard Space Flight Center and the NASA High-End Computing (HEC) Program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center | en_US |
| dc.description.uri | https://www.sciencedirect.com/science/article/pii/S0034425720300468 | en_US |
| dc.format.extent | 17 pages | en_US |
| dc.genre | journal articles | en_US |
| dc.identifier | doi:10.13016/m2kfem-zzl2 | |
| dc.identifier.citation | Zhang, Qingyuan et al. "Evaluating impacts of snow, surface water, soil and vegetation on empirical vegetation and snow indices for the Utqiaġvik tundra ecosystem in Alaska with the LVS3 model." Remote Sensing of Environment, 240, (4 February 2020). https://doi.org/10.1016/j.rse.2020.111677 | en_US |
| dc.identifier.uri | https://doi.org/10.1016/j.rse.2020.111677 | |
| dc.identifier.uri | http://hdl.handle.net/11603/26053 | |
| dc.language.iso | en_US | en_US |
| dc.publisher | Elsevier | en_US |
| dc.relation.isAvailableAt | The University of Maryland, Baltimore County (UMBC) | |
| dc.relation.ispartof | UMBC Joint Center for Earth Systems Technology | |
| dc.relation.ispartof | UMBC Faculty Collection | |
| dc.relation.ispartof | UMBC GESTAR II | |
| dc.rights | This work was written as part of one of the author's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law. | en_US |
| dc.rights | Public Domain Mark 1.0 | * |
| dc.rights.uri | http://creativecommons.org/publicdomain/mark/1.0/ | * |
| dc.title | Evaluating impacts of snow, surface water, soil and vegetation on empirical vegetation and snow indices for the Utqiaġvik tundra ecosystem in Alaska with the LVS3 model | en_US |
| dc.type | Text | en_US |
| dcterms.creator | https://orcid.org/0000-0003-4148-9108 | en_US |