Characterizing the long-term variability of snow-cover extent over the interior of North America

Abstract

ABSTRACT. Hi stori cal a nd reco nstru c ted sno w-co\'e r d a ta show e\'id e nce of a g radu a l in c rease in sno w cove r over th e co ntin enta l interi o r of K o rth Am eri ca (NA ) during mu ch of th e 20 t h century, primaril y in res po nse to in c reas ing snowfa ll, A ra pid d ec rease in C a nadi a n-pra iri e snow cove r a ft e r 1970 is no t observed O\'e r th e Grea t Pl a ins. An a lysis of snow-cove r-clim a te rela ti o nships re\'ea led sys tem a ti c in c reases in th e se nsitivity of snow cove r to North e rn H emisph ere (NH ) te mpera tures O\'e r th e 1940-65 pe ri od. Thi s ch a nge is mainl y du e to a n in c rease in snowfa ll-tempera ture se nsiti vity during this period , Season a l a na lysis re\'ealed th a t th e o bse rved in crease in snow-cove r a nd snowfa ll tempera ture se nsiti\'ity is prim a ril y a spring ph enom eno n. A m a rked in crease in th e importa nce of th e sprin g peri od is obse rved a ro und 1960, whi c h coin cid es with a well-d oc um e nted c ha nge in a tm os ph eri c circ ul a ti o n ove r NA . Th e pos t-1960 peri od is cha rac teri zed by a sig nifi ca n t in ve rse rela ti o nshi p be twee n sno \\' cover a nd hemi sph e ri c air te mpe ra ture ove r th e Ca nadi a n pra iri es a nd north ern G rea t Pl a in s regio ns,

Changes in flowering and abundance of Delphinium nuttallianum (Ranunculaceae) in response to a subalpine climate warming experiment

“…The experiment fails to warm the air over the unenclosed plots, it does not increase CO 2 , and it does not address potential and poorly understood changes in precipitation. Although most models of climate change predict earlier snowmelt and/or later initial snow accumulation (Boer et al ., 1992; Brown et al ., 1994; CSIRO, 1994; Whetton et al ., 1996), other models of the potential consequences of climate change for winter precipitation in our study area suggest increases in snowpack (Giorgi et al ., 1998). There is evidence that this is indeed occurring.…”

Integrating Experimental and Gradient Methods in Ecological Climate Change Research

“…Global warming in high elevation and latitude regions is likely to alter snow regimes, including reductions in snowpack levels and shorter periods of winter snow coverage (e.g., Brown et al 1994, Whetton et al 1996). Many researchers have reported strong relationships between snowpack timing and structure and various aspects of plant performance including distribution, growth, productivity, flowering phenology, and reproductive success (see Dunne et al 2003 for overview).…”

Subalpine Meadow Flowering Phenology Responses to Climate Change: Integrating Experimental and Gradient Methods

“…4 Present address: Santa Fe Institute, 1399 Hyde Park Road, Santa Fe, New Mexico 87501 USA. E-mail: jdunne@santafe.edu pack, scientists predict that global warming will significantly reduce the duration and extent of snow cover during the year (Boer et al 1992, Brown et al 1994, CSIRO 1994, Whetton et al 1996, with some changes already occurring (Baumgartner and Apfl 1994, Groisman et al 1994, IPCC 2001. In northern montane regions, climate change may lead to more winter precipitation, resulting in initial increases in snowpack at high elevations (Johnson 1998, Inouye et al 2000.…”