Combining observations in the reflective solar and thermal domains for improved carbon and energy flux estimation

Rasmus Houborg*, Martha C. Anderson, William P. Kustas

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

Abstract

This study investigates the utility of integrating remotely sensed estimates of leaf chlorophyll (C ab) into a thermalbased Two-Source Energy Balance (TSEB) model that estimates land-surface CO2 and energy fluxes using an analytical, light-use-efficiency (LUE) based model of canopy resistance. The LUE model component computes canopy-scale carbon assimilation and transpiration fluxes and incorporates LUE modifications from a nominal (species-dependent) value (LUE n) in response to variations in environmental conditions. However LUE n needs adjustment on a daily timescale to accommodate changes in plant physiological condition and nutrient status. Day to day variations in LUE n were assessed for a corn crop field in Maryland U.S.A. through model calibration with CO 2 flux tower observations. The optimized daily LUE n values were then compared to estimates of C ab integrated from gridded maps of chlorophyll content weighted over the tower flux source area. The time-continuous maps of daily C ab over the study field were generated by fusing in-situ measurements with retrievals generated with an integrated radiative transfer modeling tool using at-sensor radiances in green, red and near-infrared wavelengths acquired with an aircraft imaging system. The resultant daily changes in C ab within the tower flux source area exhibited a curvilinear relationship with corresponding changes in daily calibrated LUE n values derived from the tower flux data, and hourly water, energy and carbon flux estimation accuracies from TSEB were significantly improved when using C ab for delineating spatio-temporal variations in LUE n. The applicability of the established relationship between LUE n and C ab is currently being tested for an agricultural area near Bushland, Texas using a combination of reflective and thermal satellite imagery from SPOT, Landsat and ASTER.

Original languageEnglish (US)
Title of host publicationAmerican Society for Photogrammetry and Remote Sensing Annual Conference 2010
Subtitle of host publicationOpportunities for Emerging Geospatial Technologies
Pages301-307
Number of pages7
Volume1
StatePublished - 2010
Externally publishedYes
EventAmerican Society for Photogrammetry and Remote Sensing Annual Conference 2010: Opportunities for Emerging Geospatial Technologies - San Diego, CA, United States
Duration: Apr 26 2010Apr 30 2010

Other

OtherAmerican Society for Photogrammetry and Remote Sensing Annual Conference 2010: Opportunities for Emerging Geospatial Technologies
CountryUnited States
CitySan Diego, CA
Period04/26/1004/30/10

ASJC Scopus subject areas

  • Information Systems
  • Computers in Earth Sciences

Fingerprint

Dive into the research topics of 'Combining observations in the reflective solar and thermal domains for improved carbon and energy flux estimation'. Together they form a unique fingerprint.

Cite this