Stephan Custer | Montana State University - Bozeman (original) (raw)
Papers by Stephan Custer
Abstract: Yellowstone National Park (YNP) is legally mandated to monitor geo-thermal features for... more Abstract: Yellowstone National Park (YNP) is legally mandated to monitor geo-thermal features for their future preservation, and remote sensing is a component of the current monitoring plan. Landsat imagery was explored as a tool for mapping terrestrial emittance and geothermal heat flux for this purpose. Several methods were compared to estimate terrestrial emittance and geothermal heat flux (GHF) using
Wet avalanches are a safety concern for all ski areas because they are difficult to control artif... more Wet avalanches are a safety concern for all ski areas because they are difficult to control artificially and the shift from safe to dangerous wet snow conditions can happen very quickly. Forecasting for wet avalanche conditions in intermountain ski areas, such as Bridger Bowl, Montana, can be especially difficult because intermountain snow climates can exhibit wet avalanche characteristics of either maritime or continental snow climates. Various statistical models have been developed for avalanche prediction; however, most are tailored specifically for dry avalanche forecasting. Archived meteorological, snowpack and avalanche data for the month of March from 1968 to 2001 (1996 data unavailable) were used to develop 68 possible predictor variables related to temperature, snowpack settlement, and precipitation characteristics. The original Bridger Bowl dataset was divided into a ‘new snow’ and an ‘old snow’ dataset. A ‘new snow’ day has newly fallen snow that is less than 48 hours old...
Water Resources Research, 1983
Journal of the American Water Resources Association, 1996
Page 1. WATER RESOURCES BULLETIN VOL. 32, NO.2 AMERICANWATER RESOURCES ASSOCIATION APRIL 1996 A C... more Page 1. WATER RESOURCES BULLETIN VOL. 32, NO.2 AMERICANWATER RESOURCES ASSOCIATION APRIL 1996 A COMPARISON OF HAND-AND SPLINE-DRAWN PRECIPITATION MAPS FOR MOUNTAINOUS MONTANA' ...
Journal of Geological Education, 1991
Proceedings of the 2004 International Snow Science Workshop Jackson Hole Wyoming, 2004
Proceedings of the 2004 International Snow Science Workshop Jackson Hole Wyoming, 2004
Few avalanche forecast models are tailored specifically for wet avalanche forecasting. Bridger Bo... more Few avalanche forecast models are tailored specifically for wet avalanche forecasting. Bridger Bowl (intermountain climate) is a good area to develop a wet avalanche probability model. The primary archived data consists of eight variables. The archived data for March from 1968 to 2001 (1996 data unavailable) were used to develop 68 predictor variables related to temperature, snowpack settlement, and precipitation. The original dataset was divided into days with snowfall in the past 48 hours (new snow) and days without (old snow). There were 33 significant old snow variables and 22 significant new snow variables. Six variables are common to both old and new snow. The best predictor variables for old and new snow are different. The variables were analyzed with binomial logistic regression to produce probability models for old snow and for new snow wet avalanche conditions. The old snow model uses the prediction day minimum temperature and the two-day change in total snow depth as predictor variables and has a 89% overall success rate. However, the majority of this success is due to correct prediction of days without wet avalanches (96% of all correct predictions). The new snow model uses the prediction day minimum temperature and three-day cumulative new snow water equivalent as predictor variables, but is less useful. The models are applicable only to Bridger Bowl. The numerical forecast models can be used as one of the tools in the forecasting toolbox but limited data and complexity of process require that the decisions about closure remain in the hands of the ski patrol.
Proceedings of the 2004 International Snow Science Workshop Jackson Hole Wyoming, 2004
2010 International Snow Science Workshop, 2010
Understanding the spatial distribution of weak layers is a significant challenge for avalanche fo... more Understanding the spatial distribution of weak layers is a significant challenge for avalanche forecasters. Thus, improving our understanding of the processes that dictate the formation and persistence of surface weak layers across large areas is critically important for improving backcountry avalanche forecasting accuracy. For this work, heli-skiing guides mapped unburied surface hoar and near-surface facets across the Chilkat and Takhinsha Mountains of southeast Alaska during two major formation events of the 2010 season. After burial, we monitored weak layer persistence and avalanche activity. Our study area encompasses 900 km 2 of rugged, glaciated, alpine terrain, at elevations ranging from 300 m to 2000 m. Guides collected information on crystal attributes and terrain characteristics at each location, and used handheld GPS units to reference locations. Incorporating the data into a Geographic Information System (GIS) proved to be invaluable for managing and visualizing observations. For example, the GIS allowed the creation of surface condition maps that we used operationally in guide meetings and in the helicopter for making run decisions. Data analyses quantified observed patterns. In particular, we often found that surface hoar crystal size lessened with decreasing elevation, possibly due to stronger katabatic winds in valley bottoms. Additionally, we observed areas of inhibited surface hoar formation and persistence which may have resulted from the influence of synoptic inflow and outflow drainage winds. By better understanding the distribution of surface hoar and near-surface facets, this work provides insights into improved backcountry forecasting of avalanche conditions over large areas.
Engineering Approaches to Ecosystem Restoration, 1998
The removal and disposal of ground water during production of coalbed methane has the potential t... more The removal and disposal of ground water during production of coalbed methane has the potential to influence wetland-bird habitat in the Powder River Basin. Office analysis of wetland areas was conducted on National Wetland Inventory maps and Digital Orthophoto Quadrangles along the Tongue and Powder rivers in the northern Powder River Basin, Montana. Selected sites were palustrine emergent, large enough to be important to waterbirds, part of a wetland complex, not dependent on artificial water regimes, in an area with high potential for coalbed methane production, and judged to be accessible in the field. Several promising wetland areas were selected for field examination. Field investigation suggests that the most promising wetlands in oxbow cutoffs would not be productive sites. Only facultative not obligate wetland plants were observed, the topographic position of the wetlands suggested that flooding would be infrequent, and the stream flow would likely dilute the effect of prod...
Thesis (M.S. in Geology)--University of California, Berkeley, June 1973. Includes bibliographical... more Thesis (M.S. in Geology)--University of California, Berkeley, June 1973. Includes bibliographical references (leaves 111-114).
Yellowstone National Park contains the world's largest concentration of geothermal features, ... more Yellowstone National Park contains the world's largest concentration of geothermal features, with an estimated more than 10,000 features. The National Park Service is legally mandated to protect and monitor these natural features, and a geothermal monitoring plan including remote sensing has been approved. Inexpensive, accurate, and efficient geothermal mapping and change detection techniques are being developed to aid in monitoring geothermal features. Geothermal features are constantly changing in size, shape, distribution, and radiative flux. We are examining the change in geothermal activity in Yellowstone National Park and surrounding areas from up to 30 years ago to the present. Possible drivers of change include seismic activity, climate, geothermal energy development outside the park, and proximity to the caldera boundary. We are mapping and documenting changes in geothermally active areas and geothermal radiative flux using Landsat Thematic Mapper (TM), Enhanced Themati...
Abstract: Yellowstone National Park (YNP) is legally mandated to monitor geo-thermal features for... more Abstract: Yellowstone National Park (YNP) is legally mandated to monitor geo-thermal features for their future preservation, and remote sensing is a component of the current monitoring plan. Landsat imagery was explored as a tool for mapping terrestrial emittance and geothermal heat flux for this purpose. Several methods were compared to estimate terrestrial emittance and geothermal heat flux (GHF) using
Wet avalanches are a safety concern for all ski areas because they are difficult to control artif... more Wet avalanches are a safety concern for all ski areas because they are difficult to control artificially and the shift from safe to dangerous wet snow conditions can happen very quickly. Forecasting for wet avalanche conditions in intermountain ski areas, such as Bridger Bowl, Montana, can be especially difficult because intermountain snow climates can exhibit wet avalanche characteristics of either maritime or continental snow climates. Various statistical models have been developed for avalanche prediction; however, most are tailored specifically for dry avalanche forecasting. Archived meteorological, snowpack and avalanche data for the month of March from 1968 to 2001 (1996 data unavailable) were used to develop 68 possible predictor variables related to temperature, snowpack settlement, and precipitation characteristics. The original Bridger Bowl dataset was divided into a ‘new snow’ and an ‘old snow’ dataset. A ‘new snow’ day has newly fallen snow that is less than 48 hours old...
Water Resources Research, 1983
Journal of the American Water Resources Association, 1996
Page 1. WATER RESOURCES BULLETIN VOL. 32, NO.2 AMERICANWATER RESOURCES ASSOCIATION APRIL 1996 A C... more Page 1. WATER RESOURCES BULLETIN VOL. 32, NO.2 AMERICANWATER RESOURCES ASSOCIATION APRIL 1996 A COMPARISON OF HAND-AND SPLINE-DRAWN PRECIPITATION MAPS FOR MOUNTAINOUS MONTANA' ...
Journal of Geological Education, 1991
Proceedings of the 2004 International Snow Science Workshop Jackson Hole Wyoming, 2004
Proceedings of the 2004 International Snow Science Workshop Jackson Hole Wyoming, 2004
Few avalanche forecast models are tailored specifically for wet avalanche forecasting. Bridger Bo... more Few avalanche forecast models are tailored specifically for wet avalanche forecasting. Bridger Bowl (intermountain climate) is a good area to develop a wet avalanche probability model. The primary archived data consists of eight variables. The archived data for March from 1968 to 2001 (1996 data unavailable) were used to develop 68 predictor variables related to temperature, snowpack settlement, and precipitation. The original dataset was divided into days with snowfall in the past 48 hours (new snow) and days without (old snow). There were 33 significant old snow variables and 22 significant new snow variables. Six variables are common to both old and new snow. The best predictor variables for old and new snow are different. The variables were analyzed with binomial logistic regression to produce probability models for old snow and for new snow wet avalanche conditions. The old snow model uses the prediction day minimum temperature and the two-day change in total snow depth as predictor variables and has a 89% overall success rate. However, the majority of this success is due to correct prediction of days without wet avalanches (96% of all correct predictions). The new snow model uses the prediction day minimum temperature and three-day cumulative new snow water equivalent as predictor variables, but is less useful. The models are applicable only to Bridger Bowl. The numerical forecast models can be used as one of the tools in the forecasting toolbox but limited data and complexity of process require that the decisions about closure remain in the hands of the ski patrol.
Proceedings of the 2004 International Snow Science Workshop Jackson Hole Wyoming, 2004
2010 International Snow Science Workshop, 2010
Understanding the spatial distribution of weak layers is a significant challenge for avalanche fo... more Understanding the spatial distribution of weak layers is a significant challenge for avalanche forecasters. Thus, improving our understanding of the processes that dictate the formation and persistence of surface weak layers across large areas is critically important for improving backcountry avalanche forecasting accuracy. For this work, heli-skiing guides mapped unburied surface hoar and near-surface facets across the Chilkat and Takhinsha Mountains of southeast Alaska during two major formation events of the 2010 season. After burial, we monitored weak layer persistence and avalanche activity. Our study area encompasses 900 km 2 of rugged, glaciated, alpine terrain, at elevations ranging from 300 m to 2000 m. Guides collected information on crystal attributes and terrain characteristics at each location, and used handheld GPS units to reference locations. Incorporating the data into a Geographic Information System (GIS) proved to be invaluable for managing and visualizing observations. For example, the GIS allowed the creation of surface condition maps that we used operationally in guide meetings and in the helicopter for making run decisions. Data analyses quantified observed patterns. In particular, we often found that surface hoar crystal size lessened with decreasing elevation, possibly due to stronger katabatic winds in valley bottoms. Additionally, we observed areas of inhibited surface hoar formation and persistence which may have resulted from the influence of synoptic inflow and outflow drainage winds. By better understanding the distribution of surface hoar and near-surface facets, this work provides insights into improved backcountry forecasting of avalanche conditions over large areas.
Engineering Approaches to Ecosystem Restoration, 1998
The removal and disposal of ground water during production of coalbed methane has the potential t... more The removal and disposal of ground water during production of coalbed methane has the potential to influence wetland-bird habitat in the Powder River Basin. Office analysis of wetland areas was conducted on National Wetland Inventory maps and Digital Orthophoto Quadrangles along the Tongue and Powder rivers in the northern Powder River Basin, Montana. Selected sites were palustrine emergent, large enough to be important to waterbirds, part of a wetland complex, not dependent on artificial water regimes, in an area with high potential for coalbed methane production, and judged to be accessible in the field. Several promising wetland areas were selected for field examination. Field investigation suggests that the most promising wetlands in oxbow cutoffs would not be productive sites. Only facultative not obligate wetland plants were observed, the topographic position of the wetlands suggested that flooding would be infrequent, and the stream flow would likely dilute the effect of prod...
Thesis (M.S. in Geology)--University of California, Berkeley, June 1973. Includes bibliographical... more Thesis (M.S. in Geology)--University of California, Berkeley, June 1973. Includes bibliographical references (leaves 111-114).
Yellowstone National Park contains the world's largest concentration of geothermal features, ... more Yellowstone National Park contains the world's largest concentration of geothermal features, with an estimated more than 10,000 features. The National Park Service is legally mandated to protect and monitor these natural features, and a geothermal monitoring plan including remote sensing has been approved. Inexpensive, accurate, and efficient geothermal mapping and change detection techniques are being developed to aid in monitoring geothermal features. Geothermal features are constantly changing in size, shape, distribution, and radiative flux. We are examining the change in geothermal activity in Yellowstone National Park and surrounding areas from up to 30 years ago to the present. Possible drivers of change include seismic activity, climate, geothermal energy development outside the park, and proximity to the caldera boundary. We are mapping and documenting changes in geothermally active areas and geothermal radiative flux using Landsat Thematic Mapper (TM), Enhanced Themati...