The Cooling and Heating Impacts of a Lake and a Nearby Wetland Under
Current and Changing Climate
Abstract
Understanding the effect of different landscapes on local temperature is
important for understanding land-atmospheric interactions, and is a
critical step toward an informed urban design under a changing climate.
This presentation considers Lake Memphremagog, a transboundary water
body between Quebec and Vermont, along with one of its adjacent wetlands
as a test bed to study the impact of different water bodies on
regulating the local temperature. We use the data from two identical
climate stations to study hourly temperature, absolute and relative
humidity as well as incoming and outgoing radiation components along
with vapour pressure deficit at the lake and wetland. We benchmark the
temperature measurements in these two sites with the data gauged in an
Environment and Climate Change Canada’s weather station located between
the two sites. Using a systematic analysis, we account for the cooling
and heating impacts of the lake and the wetland and demonstrate their
underlying causes. We show that during the growing season and at the
daily scale, the cooling impacts of the wetland can cancel out the
heating impacts of the lake. This is not the case during day times, in
which the lake acts as a sink of heat, while the wetland is the source.
We show that the cooling and heating effects of the considered
lake-wetland duo can be described by the daily temperature statistics
(i.e. average, minimum, maximum and range) at the benchmark weather
station. This provides an opportunity to create stochastic models for
retrospective and prospective projections of cooling and heating impacts
of this lake-wetland duo under current and future climate.