Premium
Ground vs. surface air temperature trends: Implications for borehole surface temperature reconstructions
Author(s) -
Mann Michael E.,
Schmidt Gavin A.
Publication year - 2003
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2003gl017170
Subject(s) - northern hemisphere , environmental science , climatology , snow , atmospheric sciences , forcing (mathematics) , snow cover , surface air temperature , gcm transcription factors , general circulation model , geology , climate change , oceanography , geomorphology
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.