Sensitivities of Biogenic Volatile Organic Compounds to Climatological Factors Affected by Drought
Chavez-Figueroa, Erin Michelle
Cohan, Daniel S
Master of Science
Drought is expected to increase in both intensity and duration in our changing climate. However, the combined effects of drought conditions on the emissions of biogenic volatile organic compounds (BVOC) from vegetation are uncertain due to contradictory responses to the individual drought components. While increased temperature causes an increase in emissions, for instance, low enough soil moisture causes a decrease. This study therefore explored the impacts of variations in individual climate conditions on BVOC emissions. The sensitivity of BVOC emissions to leaf area index (LAI), photosynthetically active radiation (PAR), temperature, and precipitation were assessed using both ground measurements and the model MEGAN. While variations in PAR and LAI were less important than temperature in explaining variation in BVOC emissions, the choice of input data proved important. Satellite PAR produced lower isoprene emissions estimates than PAR generated by the meteorological model WRF. Higher resolution LAI data produced more spatial variability in isoprene emissions estimates. Drought was not found to correspond well to BVOC emissions, with temperature providing a much better predictor of emissions at a given location.