HR: 1330h
AN: H33B-11    [Abstracts]
TI: Comparative Atmospheric Energy Exchanges Over Creosote and Grass Landscapes in Central New Mexico
AU: * Carré, E D
EM: carre@virginia.edu
AF: University of Virginia Department of Environmental Sciences, 291 McCormick Road, Charlottesville, VA 22904 United States
AU: Potter, E B
EM: epotter@virginia.edu
AF: University of Virginia Department of Environmental Sciences, 291 McCormick Road, Charlottesville, VA 22904 United States
AU: Fuentes, J D
EM: jf6s@virginia.edu
AF: University of Virginia Department of Environmental Sciences, 291 McCormick Road, Charlottesville, VA 22904 United States
AU: Hayden, B P
EM: bph@virginia.edu
AF: University of Virginia Department of Environmental Sciences, 291 McCormick Road, Charlottesville, VA 22904 United States
AB: Creosote vegetation (Larrea tridentata), located in the American Southwest, has been hypothesized to release infrared-absorbing, biogenic hydrocarbons that retards nighttime radiative cooling. Once concentrated in the shallow nocturnal layer, these greenhouse gases could increase the atmosphere's absorption capacity of terrestrial radiation. This increase in greenhouse gases decreases the amount of radiation lost to the overlying atmosphere, thus increasing the radiative energy near the surface. The resulting effect is elevated near-surface temperatures due to a localized greenhouse effect. It is possible that different radiation and energy exchange processes prevail over the creosote vegetation and surrounding grasslands as the grasses are not producers of hydrocarbons. As part of this presentation, we will report on the results from field investigations carried out at the Sevilleta Long Term Ecological Research (LTER) field station in Central New Mexico. Field studies (i) define the thermal characteristics immediately above the creosote vegetation in response to the hydrocarbon greenhouse effect, (ii) determine the thermodynamic attributes of the atmospheric boundary layer over the field site, and (iii) identify the links between synoptic-scale conditions and thermal structure of the lower atmosphere. The data to be included in this presentation come from two twelve-meter micrometeorological flux towers deployed in the middle of creosote and grass vegetated landscapes. Tower sensors allow for the determination of thermodynamic and energy exchange characteristics of the lower boundary layer via meteorological and radiation measurements. Finally, a back trajectory model is employed to determine any large-scale transport of air that may affect the boundary layer conditions experienced at the field site.
DE: 0350 Pressure, density, and temperature
DE: 0399 General or miscellaneous
SC: Hydrology [H]
MN: 2005 Joint Assembly