HR: 1330h
AN: H33B-03 [Abstracts]
TI: Water Vapor Storage Change in the Canopy-Air Space of a Tall Deciduous Forest
AU: * Wade, C
EM: cmwade@indiana.edu
AF: Indiana University, Dept. of Geography - Atm. Sc., Bloomington, IN 47405 United States
AU: Dragoni, D
EM: ddragoni@indiana.edu
AF: Indiana University, Dept. of Geography - Atm. Sc., Bloomington, IN 47405 United States
AU: Schmid, H
EM: hschmid@indiana.edu
AF: Indiana University, Dept. of Geography - Atm. Sc., Bloomington, IN 47405 United States
AB:
The ability of weather and climate models to predict humidity, cloud formation and precipitation critically depends on the
exchange of water vapor between vegetation and the atmosphere. The canopy air-space in tall forests is deep enough to act as
a buffer volume that is depleted at times of well developed turbulent mixing, and gets recharged in conditions of poor
mixing. Recent studies have attributed biases in modeled vapor exchange to the misrepresentation or neglect of this
mechanism. At the Morgan-Monroe State Forest AmeriFlux site (Indiana, USA), water vapor exchange and the vapor storage
change in the canopy air-space has been observed for the last six years. The objective of this work is to calculate vapor
storage change fluxes in the canopy air-space from time increments of concentration profiles from data collected in 2003. We
relate vapor storage change fluxes to measured environmental forcing quanitites, such as net radiation, ambient vapor
pressure deficit, dew-point temperature depression, stability, and friction velocity to interpret the observed seasonal and
daily patterns. Also, changes in water vapor storage rates are compared with measured latent heat fluxes to determine how the total forest-atmosphere vapor exchange is affected by the recharging and depletion of water vapor throughout the canopy
air-space.
DE: 0315 Biosphere/atmosphere interactions
DE: 0394 Instruments and techniques
DE: 0400 Biogeosciences
DE: 1818 Evapotranspiration
SC: Hydrology [H]
MN: 2005 Joint Assembly