Enhanced climate change and its detection over the Rocky Mountains

Journal Article · Fri Jan 01 04:00:00 EST 1999 · Journal of Climate

DOI:https://doi.org/10.1175/1520-0442-12.1.230· OSTI ID:323738

Fyfe, J C; Flato, G M ^[1]

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1. Canadian Centre for Climate Modeling and Analysis, Victoria, British Columbia (Canada)

Results from an ensemble of climate change experiments with increasing greenhouse gas and aerosols using the Canadian Centre for Climate Modeling and Analysis Coupled Climate Model are presented with a focus on surface quantities over the Rocky Mountains. There is a marked elevation dependency of the simulated surface screen temperature increase over the Rocky Mountains in the winter and spring seasons, with more pronounced changes at higher elevations. The elevation signal is linked to a rise in the snow line in the winter and spring seasons, which amplifies the surface warming via the snow-albedo feedback. Analysis of the winter surface energy budget shows that large changes in the solar component of the radiative input are the direct consequence of surface albedo changes caused by decreasing snow cover. Although the warming signal is enhanced at higher elevations, a two-way analysis of variance reveals that the elevation effect has no potential for early climate change detection. In the early stages of surface warming the elevation effect is masked by relatively large noise, so that the signal-to-noise ratio over the Rocky Mountains is no larger than elsewhere. Only after significant continental-scale warming does the local Rocky Mountain signal begin to dominate the pattern of climate change over western North America (and presumably also the surrounding ecosystems and hydrological networks).

• Sponsoring Organization: USDOE
• OSTI ID: 323738
• Journal Information: Journal of Climate, Journal Name: Journal of Climate Journal Issue: 1 Vol. 12; ISSN 0894-8755; ISSN JLCLEL
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
AEROSOLS
AMBIENT TEMPERATURE
CLIMATE MODELS
ENVIRONMENTAL IMPACTS
GREENHOUSE EFFECT
GREENHOUSE GASES
ROCKY MOUNTAINS
SEASONAL VARIATIONS