TY - JOUR
T1 - Ground vs. surface air temperature trends
T2 - Implications for borehole surface temperature reconstructions
AU - Mann, Michael E.
AU - Schmidt, Gavin A.
PY - 2003/6/15
Y1 - 2003/6/15
N2 - We have analyzed the relationship between surface air temperature (SAT), ground surface temperature (GST), and snow cover (SNC) over the terrestrial Northern Hemisphere based on general circulation model (GCM) simulations using GISS modelE forced with the observed SST and radiative forcing changes from 1951 - 1998. While SAT is the dominant influence on GST during the warm-season, it explains only half of the variance in GST during the cold-season, with SNC and pre-conditioning by prior warm-season SAT also exhibiting a sizeable and, in places, dominant influence. During a period of coincident surface warming and cold-season snowcover decrease in the model (1971-1998), mean GST increases are 0.2°C less than those in SAT, a consequence of greater exposure of the ground surface to winter cold air outbreaks. Interpretations of past SAT trends from borehole-based GST reconstructions may therefore be substantially biased by seasonal influences and snow cover changes.
AB - We have analyzed the relationship between surface air temperature (SAT), ground surface temperature (GST), and snow cover (SNC) over the terrestrial Northern Hemisphere based on general circulation model (GCM) simulations using GISS modelE forced with the observed SST and radiative forcing changes from 1951 - 1998. While SAT is the dominant influence on GST during the warm-season, it explains only half of the variance in GST during the cold-season, with SNC and pre-conditioning by prior warm-season SAT also exhibiting a sizeable and, in places, dominant influence. During a period of coincident surface warming and cold-season snowcover decrease in the model (1971-1998), mean GST increases are 0.2°C less than those in SAT, a consequence of greater exposure of the ground surface to winter cold air outbreaks. Interpretations of past SAT trends from borehole-based GST reconstructions may therefore be substantially biased by seasonal influences and snow cover changes.
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U2 - 10.1029/2003GL017170
DO - 10.1029/2003GL017170
M3 - Article
AN - SCOPUS:0347413673
SN - 0094-8276
VL - 30
SP - 9-1 - 9-4
JO - Geophysical Research Letters
JF - Geophysical Research Letters
IS - 12
ER -