Home

Variable seasonal coupling between air and ground temperatures: A simple representation in terms of subsurface thermal diffusivity

Henry N. Pollack; Jason E. Smerdon; Peter E. van Keken

Title:
Variable seasonal coupling between air and ground temperatures: A simple representation in terms of subsurface thermal diffusivity
Author(s):
Pollack, Henry N.
Smerdon, Jason E.
Keken, Peter E. van
Date:
Type:
Articles
Department:
Lamont-Doherty Earth Observatory
Volume:
32
Permanent URL:
Book/Journal Title:
Geophysical Research Letters
Abstract:
The utility of subsurface temperatures as indicators of temperature changes at Earth's surface rests upon an assumption of strong coupling between surface air temperature (SAT) and ground surface temperature (GST). Here we describe a simple representation of this coupling in terms of a variable thermal diffusivity in the upper meter of the subsurface. The variability is tied to daily SAT, precipitation, and snow cover, but does not incorporate the physical details of these and the many other factors that influence the air-ground interface in many high-fidelity land-surface models. Our simple model reduces the difference between observed and modeled temperatures by a factor of 3 to 4 over a model with uniform diffusivity driven only by SAT. This simple representation of air-ground coupling offers a means of simulating subsurface temperatures using only archived meteorological records and creates the potential for examining the long term character of air-ground temperature coupling.
Subject(s):
Atmospheric sciences
Paleoclimate science
Hydrologic sciences
Publisher DOI:
http://dx.doi.org/10.1029/2005GL023869
Item views:
178
Metadata:
text | xml

In Partnership with the Center for Digital Research and Scholarship at Columbia University Libraries/Information Services | Terms of Use