Frequency of Major Avalanche Winters

AbstractA 70-Year record has been compiled for avalanches affecting the Canadian Pacific Railway at Rogers Pass, British Columbia. Time series are presented for avalanche frequency, avalanche mass, and length of avalanche debris on the rail line for 26 avalanche paths as well as for winter snow-fall. Winters with the heaviest avalanche activity were 1971-72, 1934-35, 1919-20, 1932-33, and 1953-54. Time-series analysis indicates that the size of avalanches has decreased in recent decades. Spectral analysis shows avalanche activity to the similar to white noise but with a weak periodicity of about 18 years. An examination of the climatology of big avalanche winters reveals two distinct circulation patterns: a strong zonal flow with frequent Pacific storms and heavy snow-fall; or a pronounced meridional flow, Arctic air outbreaks, and catastrophic avalanching released by rapid advection of warm moist Pacific air. Major avalanche winters need not be big snow-fall winters.

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Frequency of Major Avalanche Winters

Journal of Glaciology ◽

10.1017/s0022143000010571 ◽

1980 ◽

Vol 26 (94) ◽

pp. 43-52 ◽

Cited By ~ 15

Author(s):

B.B. Fitzharris ◽

P. A. Schaerer

Keyword(s):

Time Series ◽

Spectral Analysis ◽

Zonal Flow ◽

Meridional Flow ◽

Winter Snow ◽

Circulation Patterns ◽

Rail Line ◽

Heavy Snow ◽

Canadian Pacific Railway ◽

Snow Fall

Abstract A 70-Year record has been compiled for avalanches affecting the Canadian Pacific Railway at Rogers Pass, British Columbia. Time series are presented for avalanche frequency, avalanche mass, and length of avalanche debris on the rail line for 26 avalanche paths as well as for winter snow-fall. Winters with the heaviest avalanche activity were 1971-72, 1934-35, 1919-20, 1932-33, and 1953-54. Time-series analysis indicates that the size of avalanches has decreased in recent decades. Spectral analysis shows avalanche activity to the similar to white noise but with a weak periodicity of about 18 years. An examination of the climatology of big avalanche winters reveals two distinct circulation patterns: a strong zonal flow with frequent Pacific storms and heavy snow-fall; or a pronounced meridional flow, Arctic air outbreaks, and catastrophic avalanching released by rapid advection of warm moist Pacific air. Major avalanche winters need not be big snow-fall winters.

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An Apparent One-Year Lag Relationship of Heavy Snow Years Between Eurasia and North America

Annals of Glaciology ◽

10.1017/s0260305500008405 ◽

1990 ◽

Vol 14 ◽

pp. 124-126

Author(s):

Tomohiko Iwasaki

Keyword(s):

Time Series ◽

North America ◽

Snow Cover ◽

Northern Hemisphere ◽

Total Variance ◽

Continental Scale ◽

Winter Snow ◽

Heavy Snow ◽

One Year ◽

Relationship Of

The purpose of this study is to investigate the interannual variability of winter snow cover in the northern hemisphere, using the satellite-derived monthly snow cover data (NOAA/NESDIS) from 1967 to 1987. An empirical orthogonal function (EOF) analysis is made to see the typical pattern of snow cover variations during winter. EOF1, which represents about 40% of the total variance, shows concurrent snow cover patterns between Eurasia and North America. EOF2, which represents over 20% of the total variance, shows a negatively correlated pattern between the eastern and western parts of the continent in Eurasia and North America. We examined time series of mean snow cover for key regions of the northern hemisphere to investigate variations depicted in the EOF patterns in more detail. We selected two key regions which represent continental-scale snow variation. One is the eastern part of Eurasia and the other is the western part of North America. The time series of the two key regions show an apparent one-year lag relationship of heavy snow cover years; winters with extensive snow cover over Eurasia tend to be followed by extensive snow cover over North America during the succeeding winters.

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An Apparent One-Year Lag Relationship of Heavy Snow Years Between Eurasia and North America

Annals of Glaciology ◽

10.3189/s0260305500008405 ◽

1990 ◽

Vol 14 ◽

pp. 124-126

Author(s):

Tomohiko Iwasaki

Keyword(s):

Time Series ◽

North America ◽

Snow Cover ◽

Northern Hemisphere ◽

Total Variance ◽

Continental Scale ◽

Winter Snow ◽

Heavy Snow ◽

One Year ◽

Relationship Of

The purpose of this study is to investigate the interannual variability of winter snow cover in the northern hemisphere, using the satellite-derived monthly snow cover data (NOAA/NESDIS) from 1967 to 1987. An empirical orthogonal function (EOF) analysis is made to see the typical pattern of snow cover variations during winter. EOF1, which represents about 40% of the total variance, shows concurrent snow cover patterns between Eurasia and North America. EOF2, which represents over 20% of the total variance, shows a negatively correlated pattern between the eastern and western parts of the continent in Eurasia and North America.We examined time series of mean snow cover for key regions of the northern hemisphere to investigate variations depicted in the EOF patterns in more detail. We selected two key regions which represent continental-scale snow variation. One is the eastern part of Eurasia and the other is the western part of North America. The time series of the two key regions show an apparent one-year lag relationship of heavy snow cover years; winters with extensive snow cover over Eurasia tend to be followed by extensive snow cover over North America during the succeeding winters.

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Spectral Analysis of Time Series with Rhythmic Structure

Journal of Automation and Information Sciences ◽

10.1615/jautomatinfscien.v31.i1-3.130 ◽

1999 ◽

Vol 31 (1-3) ◽

pp. 100-107

Author(s):

I. N. Yavorskiy ◽

I. Yu. Isaev

Keyword(s):

Time Series ◽

Spectral Analysis ◽

Rhythmic Structure ◽

Analysis Of Time Series

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Time Series Long Memory Identification and Quantile Spectral Analysis.

10.21236/ada132240 ◽

1983 ◽

Author(s):

Emanuel Parzen

Keyword(s):

Time Series ◽

Spectral Analysis ◽

Long Memory

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Stationary Time Series Analysis Using Information and Spectral Analysis

10.21236/ada257279 ◽

1992 ◽

Author(s):

Emanuel Parzen

Keyword(s):

Time Series ◽

Spectral Analysis ◽

Time Series Analysis ◽

Stationary Time Series ◽

Series Analysis ◽

Stationary Time

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Assessing Stream-Aquifer Connectivity in a Coastal California Watershed

Water ◽

10.3390/w13040416 ◽

2021 ◽

Vol 13 (4) ◽

pp. 416

Author(s):

Bwalya Malama ◽

Devin Pritchard-Peterson ◽

John J. Jasbinsek ◽

Christopher Surfleet

Keyword(s):

Time Series ◽

Spectral Analysis ◽

Water Level ◽

Time Series Data ◽

Series Data ◽

Low Permeability ◽

Pumping Tests ◽

Stream Flows ◽

The Impact

We report the results of field and laboratory investigations of stream-aquifer interactions in a watershed along the California coast to assess the impact of groundwater pumping for irrigation on stream flows. The methods used include subsurface sediment sampling using direct-push drilling, laboratory permeability and particle size analyses of sediment, piezometer installation and instrumentation, stream discharge and stage monitoring, pumping tests for aquifer characterization, resistivity surveys, and long-term passive monitoring of stream stage and groundwater levels. Spectral analysis of long-term water level data was used to assess correlation between stream and groundwater level time series data. The investigations revealed the presence of a thin low permeability silt-clay aquitard unit between the main aquifer and the stream. This suggested a three layer conceptual model of the subsurface comprising unconfined and confined aquifers separated by an aquitard layer. This was broadly confirmed by resistivity surveys and pumping tests, the latter of which indicated the occurrence of leakage across the aquitard. The aquitard was determined to be 2–3 orders of magnitude less permeable than the aquifer, which is indicative of weak stream-aquifer connectivity and was confirmed by spectral analysis of stream-aquifer water level time series. The results illustrate the importance of site-specific investigations and suggest that even in systems where the stream is not in direct hydraulic contact with the producing aquifer, long-term stream depletion can occur due to leakage across low permeability units. This has implications for management of stream flows, groundwater abstraction, and water resources management during prolonged periods of drought.

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