LONG-TERM CLIMATE MONITORING NETWORK at the MOUNTAIN RESEARCH STATION,
UNIVERSITY OF COLORADO
LOSLEBEN, MARK (1, 2); CHOWANSKI, KURT (1, 2); ACKERMAN, TODD (2)
(1) University of Colorado, INSTAAR, Mountain Research Station, Nederland, CO 80466, (2)
University of Colorado, INSTAAR, LTER
The value of long-term monitoring of mountain climate cannot be overstated. CU’s Mountain
Research Station operates a climate monitoring network of eleven stations in the Front Range of
Colorado, ranging in elevation from 3814m at the Continental Divide, and eastward to 2199m.
Monitoring at four stations began over half a century ago.
Time series, trends, and climate extremes are presented, and a ‘dry’ zone phenomenon is
discussed and supported with data. Temporally, there is a significant positive precipitation trend
in the alpine, but not in the upper montaine forest, and a positive temperature trend in the upper
montaine forest, but not in the alpine.
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A ‘dry’ zone may be unique to lee slopes where lee-side cyclogenisis occurs during the passage
of low pressure (storm) systems. This ‘dry’ zone will be located between higher elevations where
westerly-driven orographic precipitation dominates, and lower elevations, which receive more
easterly upslope precipitation. Since winter circulation conditions are the primary cause of the
’dry’ zone, the effect on snowpack would be more pronounced than on summer rains.Such a ‘dry’
elevational precipitation band is theoretically probable on all lee slopes of mountain ranges with
long north-south geographical extents in the westerly wind dominated mid-latitudes.