Abstract

Isoprene emissions from vegetation significantly contribute to tropospheric chemistry. The oxidation of isoprene in the troposphere can lead to the formation of pollutants such as tropospheric ozone (0₃) , carbon monoxide, and organic peroxides. In order to better predict future isoprene emissi... Show moreIsoprene emissions from vegetation significantly contribute to tropospheric chemistry. The oxidation of isoprene in the troposphere can lead to the formation of pollutants such as tropospheric ozone (0₃) , carbon monoxide, and organic peroxides. In order to better predict future isoprene emissions, it is necessary to create accurate models that incorporate all the parameters that control isoprene emission capacity. The shortterm effects of temperature on isoprene emissions have been well studied, but the longterm effects are still unclear. We measured the long-term effects of temperature on isoprene emission capacity from aspen leaves in the field between July 7 and July 30, 1999. We measured base emission rate (BER), defined as the emiss ion rate at of 25°C and 1000 PAR, three times a week. Although a preliminary analysis of the data shows that there is only a slight correlation between previous day's temperature and change in the BER, the closest association between isoprene emissions and temperature occurred within the same day that the data was collected. The implications for model parameters are that long-term effects should be incorporated into the model, but they may not be on the scale of days. Long-term effects of temperature on the order of hours seems to be more appropriate. Show less