Martha P. Butler

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The aim of this case study is to examine the surface layer CO 2 budget and possible impacts of advection on the 20 km scale on estimates of net ecosystem–atmosphere exchange (NEE) of CO 2 under windy conditions. The advection terms in the CO 2 mixing ratio conservation equation are computed using data from two flux towers 20 km apart in a forested area in(More)
Mixing ratios of CO 2 often change abruptly in the presence of inclement weather and low pressure systems. Water vapor mixing ratio, temperature, wind speed, and wind direction data are used to infer that the abrupt changes in CO 2 mixing ratios at a site in northern Wisconsin are due to tropospheric mixing, horizontal transport, or a combination of both(More)
[1] Difficulties in estimating terrestrial ecosystem CO 2 fluxes on regional scales have significantly limited our understanding of the global carbon cycle. This paper presents an effort to estimate daytime CO 2 fluxes over a forested region on the scale of 50 km in northern Wisconsin, USA, using the tall-tower-based mixed layer (ML) budget method. Budget(More)
Integrated assessment models for climate change (IAMs) couple representations of economic and natural systems to identify and evaluate strategies for managing the effects of global climate change. In this study we subject the Dynamic Integrated model of Climate and Economy (DICE), an IAM of lower-bound complexity , to a comprehensive global sensitivity(More)
The dimensionless bottom-up and top-down gradient functions in the convective boundary layer (CBL) are evaluated utilizing long-term well-calibrated carbon dioxide mixing ratio and flux measurements from multiple levels of a 447-m tall tower over a forested area in northern Wisconsin, USA. The estimated bottom-up and top-down functions are qualitatively(More)
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