The Impact of Observed Vegetation Changes on Land–Atmosphere Feedbacks During Drought

Handle URI:
http://hdl.handle.net/10754/552740
Title:
The Impact of Observed Vegetation Changes on Land–Atmosphere Feedbacks During Drought
Authors:
Meng, X. H.; Evans, J. P. ( 0000-0003-1776-3429 ) ; McCabe, Matthew ( 0000-0002-1279-5272 )
Abstract:
Moderate Resolution Imaging Spectroradiometer (MODIS)-derived vegetation fraction data were used to update the boundary conditions of the advanced research Weather Research and Forecasting (WRF) Model to assess the influence of realistic vegetation cover on climate simulations in southeast Australia for the period 2000–08. Results show that modeled air temperature was improved when MODIS data were incorporated, while precipitation changes little with only a small decrease in the bias. Air temperature changes in different seasons reflect the variability of vegetation cover well, while precipitation changes have a more complicated relationship to changes in vegetation fraction. Both MODIS and climatology-based simulation experiments capture the overall precipitation changes, indicating that precipitation is dominated by the large-scale circulation, with local vegetation changes contributing variations around these. Simulated feedbacks between vegetation fraction, soil moisture, and drought over southeast Australia were also investigated. Results indicate that vegetation fraction changes lag precipitation reductions by 6–8 months in nonarid regions. With the onset of the 2002 drought, a potential fast physical mechanism was found to play a positive role in the soil moisture–precipitation feedback, while a slow biological mechanism provides a negative feedback in the soil moisture–precipitation interaction on a longer time scale. That is, in the short term, a reduction in soil moisture leads to a reduction in the convective potential and, hence, precipitation, further reducing the soil moisture. If low levels of soil moisture persist long enough, reductions in vegetation cover and vigor occur, reducing the evapotranspiration and thus reducing the soil moisture decreases and dampening the fast physical feedback. Importantly, it was observed that these feedbacks are both space and time dependent.
KAUST Department:
Water Desalination and Reuse Research Center (WDRC)
Citation:
The Impact of Observed Vegetation Changes on Land–Atmosphere Feedbacks During Drought 2014, 15 (2):759 Journal of Hydrometeorology
Publisher:
American Meteorological Society
Journal:
Journal of Hydrometeorology
Issue Date:
Apr-2014
DOI:
10.1175/JHM-D-13-0130.1
Type:
Article
ISSN:
1525-755X; 1525-7541
Additional Links:
http://journals.ametsoc.org/doi/abs/10.1175/JHM-D-13-0130.1
Appears in Collections:
Articles; Water Desalination and Reuse Research Center (WDRC)

Full metadata record

DC FieldValue Language
dc.contributor.authorMeng, X. H.en
dc.contributor.authorEvans, J. P.en
dc.contributor.authorMcCabe, Matthewen
dc.date.accessioned2015-05-14T06:25:00Zen
dc.date.available2015-05-14T06:25:00Zen
dc.date.issued2014-04en
dc.identifier.citationThe Impact of Observed Vegetation Changes on Land–Atmosphere Feedbacks During Drought 2014, 15 (2):759 Journal of Hydrometeorologyen
dc.identifier.issn1525-755Xen
dc.identifier.issn1525-7541en
dc.identifier.doi10.1175/JHM-D-13-0130.1en
dc.identifier.urihttp://hdl.handle.net/10754/552740en
dc.description.abstractModerate Resolution Imaging Spectroradiometer (MODIS)-derived vegetation fraction data were used to update the boundary conditions of the advanced research Weather Research and Forecasting (WRF) Model to assess the influence of realistic vegetation cover on climate simulations in southeast Australia for the period 2000–08. Results show that modeled air temperature was improved when MODIS data were incorporated, while precipitation changes little with only a small decrease in the bias. Air temperature changes in different seasons reflect the variability of vegetation cover well, while precipitation changes have a more complicated relationship to changes in vegetation fraction. Both MODIS and climatology-based simulation experiments capture the overall precipitation changes, indicating that precipitation is dominated by the large-scale circulation, with local vegetation changes contributing variations around these. Simulated feedbacks between vegetation fraction, soil moisture, and drought over southeast Australia were also investigated. Results indicate that vegetation fraction changes lag precipitation reductions by 6–8 months in nonarid regions. With the onset of the 2002 drought, a potential fast physical mechanism was found to play a positive role in the soil moisture–precipitation feedback, while a slow biological mechanism provides a negative feedback in the soil moisture–precipitation interaction on a longer time scale. That is, in the short term, a reduction in soil moisture leads to a reduction in the convective potential and, hence, precipitation, further reducing the soil moisture. If low levels of soil moisture persist long enough, reductions in vegetation cover and vigor occur, reducing the evapotranspiration and thus reducing the soil moisture decreases and dampening the fast physical feedback. Importantly, it was observed that these feedbacks are both space and time dependent.en
dc.publisherAmerican Meteorological Societyen
dc.relation.urlhttp://journals.ametsoc.org/doi/abs/10.1175/JHM-D-13-0130.1en
dc.rights© Copyright 2014 American Meteorological Society (AMS). Permission to use figures, tables, and brief excerpts from this work in scientific and educational works is hereby granted provided that the source is acknowledged. Any use of material in this work that is determined to be “fair use” under Section 107 of the U.S. Copyright Act September 2010 Page 2 or that satisfies the conditions specified in Section 108 of the U.S. Copyright Act (17 USC §108, as revised by P.L. 94-553) does not require the AMS’s permission. Republication, systematic reproduction, posting in electronic form, such as on a web site or in a searchable database, or other uses of this material, except as exempted by the above statement, requires written permission or a license from the AMS. Additional details are provided in the AMS Copyright Policy, available on the AMS Web site located at (http://www.ametsoc.org/) or from the AMS at 617-227-2425 or copyrights@ametsoc.org.en
dc.subjectSoil moistureen
dc.subjectHydrometeorologyen
dc.subjectFeedbacken
dc.subjectClimate changeen
dc.subjectAtmosphere-land interactionen
dc.titleThe Impact of Observed Vegetation Changes on Land–Atmosphere Feedbacks During Droughten
dc.typeArticleen
dc.contributor.departmentWater Desalination and Reuse Research Center (WDRC)en
dc.identifier.journalJournal of Hydrometeorologyen
dc.eprint.versionPublisher's Version/PDFen
dc.contributor.institutionClimate Change Research Centre, University of New South Wales, Sydney, New South Wales, Australia, and Key Laboratory of Land Surface Process and Climate Change in Cold and Arid Regions, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Science, Lanzhou, Chinaen
dc.contributor.institutionClimate Change Research Centre, University of New South Wales, Sydney, New South Wales, Australiaen
kaust.authorMcCabe, Matthewen
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