2026-09-20T20:46:13Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/101699 2023-07-11 col_2142_5131 com_2142_5130

Land-atmosphere interactions Dominguez, Francina Chug, Divyansh 2018-09-27T16:30:30Z 2018-09-27T16:30:30Z 2020-09-28T09:15:07Z 2018-07-13 2018-08 Land surface variability and change can affect the overlying atmosphere through biogeophysical and biogeochemical feedbacks. The goal of our work is to isolate and quantify the local and remote influences of vegetation on the climate of South America using observational records. We find that the dominant mode of vegetation variability over the La Plata River basin in austral Spring is linked with warmer temperature and enhanced precipitation over central and south La Plata basin. A key aspect of this study is the use of remotely sensed land-surface characteristics alongside reanalysis data, and the use of the generalized equilibrium feedback assessment (GEFA) to isolate the effects of each forcing. The analysis uses a 34-year (1981-2014) record of the modified enhanced vegetation index (EVI2) from the NASA MEaSUREs Vegetation Index and Phenology dataset and the third generation normalized difference vegetation index (NDVI3g) from the Global Inventory Modeling and Mapping Studies. The dominant patterns of variability in space and time are analyzed using empirical orthogonal function/principal component (EOF/PC) analysis on a basin-wide scale. The dominant mode looks like a vegetation dipole, and can be explained using observed records of precipitation provided by the University of Delaware and the University of East Anglia Climate Research Unit. The second part of the study analyzes how these dominant modes of variability affect the overlying atmosphere at the continental scale. We use GEFA and its refinement, the stepwise GEFA, to statistically quantify the observed seasonal impacts of dominant terrestrial and oceanic forcings on the South American climate. This observed impact of vegetation on the seasonal accumulation of precipitation in the agricultural growing season holds crucial importance for the most heavily populated and economically active region of South America. Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2020-08-01 The student, Divyansh Chug, accepted the attached license on 2018-07-10 at 16:37. The student, Divyansh Chug, submitted this Thesis for approval on 2018-07-10 at 16:44. This Thesis was approved for publication on 2018-07-13 at 11:18. DSpace SAF Submission Ingestion Package generated from Vireo submission #12807 on 2018-09-27 at 11:18:57 Made available in DSpace on 2018-09-27T16:30:30Z (GMT). No. of bitstreams: 2 CHUG-THESIS-2018.pdf: 2030819 bytes, checksum: cb2889a352fe053e5042d0a2937fa628 (MD5) LICENSE.txt: 4210 bytes, checksum: a2400d0d332335a304ee9a56641d221c (MD5) Previous issue date: 2018-07-13 Embargo set by: Seth Robbins for item 107797 Lift date: 2020-09-27T16:30:34Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system Embargo set by: Seth Robbins for item 107797 Lift date: 2020-09-27T16:31:43Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system Embargo set by: Seth Robbins for item 107797 Lift date: 2020-09-27T16:34:29Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system U of I Only Restriction Lifted for Item 107797 on 2020-09-28T09:15:07Z. application/pdf http://hdl.handle.net/2142/101699 en Copyright 2018 Divyansh Chug La Plata River Basin Isolating the observed influence of vegetation variability of La Plata River basin on the climate of South America text text Atmospheric Sciences Atmospheric Sciences University of Illinois at Urbana-Champaign Thesis M.S.