Spring Phenology: Nature's Experiment to Detect the Effect of “Green-Up” on Surface Maximum Temperatures

Open Access
Publisher Website
Google Scholar
Abstract
In spring many plants break dormancy and begin foliage production. The appearance of leaves (the “green-up” period) triggers a rapid increase in transpiration at the surface as well as changes in albedo. Subsequently, these processes alter the thermodynamic properties of the surface layer. Normally, seasonal variations in tropospheric thickness, and year-to-year variability in the green-up date, mask the impact of these effects on surface maximum temperatures. In this study we used first leaf phenological data (from the clone lilac Syringa chinensis in the central and eastern United States) as the indicator of transpiration onset, in order to reveal the effects of this change from a dormant vegetative surface, perhaps comparable to the worst summertime droughts, to an active foliage-producing and transpiring vegetative surface. Simple plots using average hypsometric layer-mean temperature (derived from geopotential thickness) and average surface daily maximum temperature were examined for variati... Abstract In spring many plants break dormancy and begin foliage production. The appearance of leaves (the “green-up” period) triggers a rapid increase in transpiration at the surface as well as changes in albedo. Subsequently, these processes alter the thermodynamic properties of the surface layer. Normally, seasonal variations in tropospheric thickness, and year-to-year variability in the green-up date, mask the impact of these effects on surface maximum temperatures. In this study we used first leaf phenological data (from the clone lilac Syringa chinensis in the central and eastern United States) as the indicator of transpiration onset, in order to reveal the effects of this change from a dormant vegetative surface, perhaps comparable to the worst summertime droughts, to an active foliage-producing and transpiring vegetative surface. Simple plots using average hypsometric layer-mean temperature (derived from geopotential thickness) and average surface daily maximum temperature were examined for variati...

This publication has 0 references indexed in Scilit: