Thursday, February 7, 2013

New paper finds warming causes less snow

A paper published today in the Journal of Climate finds that warmer temperatures cause less snow, and conversely, colder temperatures cause more snow. According to the authors, "Using a simple multivariate model, [increased] temperature is shown to drive these trends by decreasing snowfall almost everywhere." The paper refutes the claims of climate alarmists that global warming causes more snow.


Warmist Tobis says heavy snow is agw: calls anyone who mocks ‘clueless’

Controls of Global Snow Under a Changed Climate

Sarah B. Kapnick* and Thomas L. Delworth
Princeton University and NOAA/Geophysical Fluid Dynamics Laboratory, Princeton, New Jersey
NOAA/Geophysical Fluid Dynamics Laboratory, Princeton, New Jersey
This study assesses the ability of a newly developed high-resolution coupled model from the Geophysical Fluid Dynamics Laboratory to simulate the cold-season hydroclimate in the present climate, and examines its response to climate change forcing. Output is assessed from a 280-yr control simulation based on 1990 atmospheric composition and an idealized 140-yr future simulation where atmospheric CO2 increases at 1% yr−1 until doubling in year 70 and then remains constant.
When compared to a low-resolution model, the high-resolution model is found to better represent the geographic distribution of snow variables in the present climate. In response to idealized radiative forcing changes, both models produce similar global-scale responses where global-mean temperature and total precipitation increase while snowfall decreases. Zonally, snowfall tends to decrease in the low to mid latitudes and increase in the mid to high latitudes.
At the regional scale, the high and low-resolution models sometimes diverge in the sign of projected snowfall changes; the high-resolution model exhibits future increases in a few select high altitude regions, notably the northwestern Himalaya region and small regions in the Andes and southwestern Yukon. Despite such local signals, there is an almost universal reduction in snowfall as a percent of total precipitation in both models. Using a simple multivariate model, temperature is shown to drive these trends by decreasing snowfall almost everywhere while precipitation increases snowfall in the high altitudes and mid to high latitudes. Mountainous regions of snowfall increases in the high-resolution model exhibit a unique dominance of the positive contribution from precipitation over temperature.