Uniform TitleVariations in Northern Hemisphere snowfall: an analysis of historical trends and the projected response to anthropogenic forcing in the twenty-first century
NameKrasting, John P. (author), Broccoli, Anthony (chair), Robock, Alan (internal member), Robinson, David (internal member), Stenchikov, Georgiy (internal member), Colle, Brian (outside member), Rutgers University, Graduate School - New Brunswick,
Precipitation variability--Northern Hemisphere,
Climatic changes--Northern Hemisphere
DescriptionSnowfall is an important feature of the Earth's climate system that has the ability to influence both the natural world and human activity. This dissertation examines past and future changes in snowfall related to increasing concentrations of anthropogenic greenhouse gases. Snowfall observations for North America, derived snowfall products for the Northern Hemisphere, and simulations performed with 13 coupled atmosphere-ocean global climate models are analyzed.
The analysis of the spatial pattern of simulated annual trends on a grid point basis from 1951 to 1999 indicates that a transition zone exists above 60° N latitude across the Northern Hemisphere that separates negative trends in annual snowfall in the mid-latitudes and positive trends at higher latitudes. Regional analysis of observed annual snowfall indicates that statistically significant trends are found in western North America, Japan, and southern Russia. A majority of the observed historical trends in annual snowfall elsewhere in the Northern Hemisphere, however, are not statistically significant and this result is consistent with model simulations.
Projections of future snowfall indicate the presence of a similar transition zone between negative and positive snowfall trends that corresponds with the area between the
-10 to -15° C isotherms of the multi-model mean temperature of the late twentieth century in each of the fall, winter, and spring seasons. Redistributions of snowfall throughout the entire snow season are likely -- even in locations where there is little change in annual snowfall. Changes in the fraction of precipitation falling as snow contribute to decreases in snowfall across most Northern Hemisphere regions, while changes in precipitation typically contribute to increases in snowfall. Snowfall events less than or equal to 5 cm are found to decrease in the future across most of the Northern Hemisphere, while snowfall events greater than or equal to 20 cm increase in some
locations, such as northern Quebec. A signal-to-noise analysis reveals that the projected
changes in snowfall are likely to become apparent during the twenty-first century for most locations in the Northern Hemisphere.
NoteIncludes bibliographical references (p. 98-108).
CollectionGraduate School - New Brunswick Electronic Theses and Dissertations
Organization NameRutgers, The State University of New Jersey
RightsThe author owns the copyright to this work.