Long-term Energy-balance Modeling of Interannual Snow and Ice in Wyoming Using the Dynamic Equilibrium Concept PDF Download
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Author: Ryan J. Johnson Publisher: ISBN: 9781339054858 Category : Ice Languages : en Pages : 106
Book Description
Many snow models in the field of hydrologic engineering do not incorporate the long-term effects of the interannual snow storage such as glaciers because glacier dynamics have a much longer timescale than river flow and seasonal snowmelt. This study proposes an appropriate treatment for inland glaciers as systems in dynamic equilibrium that remain constant under a static climate condition. This new method considers the vertical movement of snow/ice from high elevation areas to valleys as the equilibrating factor of the glacier system. The vertical movement of snow/ice occurs by means of wind re-distribution, avalanches, and glaciation. This paper introduces and discusses the physically-based modeling of such a dynamic equilibrium snow system for long-term snow simulation at a regional scale. We apply the regional snow model (RegSnow) to a domain containing the entire state of Wyoming and couple the model to the Weather Research and Forecasting (WRF) model to compute the snow surface energy-balance. RegSnow predicted that 82.2% of interannual snow and ice storage in Wyoming may disappear by 2100 using temperature increases projected by CMIP5 GCMs, under the RCP4.5 emission scenario.
Author: Ryan J. Johnson Publisher: ISBN: 9781339054858 Category : Ice Languages : en Pages : 106
Book Description
Many snow models in the field of hydrologic engineering do not incorporate the long-term effects of the interannual snow storage such as glaciers because glacier dynamics have a much longer timescale than river flow and seasonal snowmelt. This study proposes an appropriate treatment for inland glaciers as systems in dynamic equilibrium that remain constant under a static climate condition. This new method considers the vertical movement of snow/ice from high elevation areas to valleys as the equilibrating factor of the glacier system. The vertical movement of snow/ice occurs by means of wind re-distribution, avalanches, and glaciation. This paper introduces and discusses the physically-based modeling of such a dynamic equilibrium snow system for long-term snow simulation at a regional scale. We apply the regional snow model (RegSnow) to a domain containing the entire state of Wyoming and couple the model to the Weather Research and Forecasting (WRF) model to compute the snow surface energy-balance. RegSnow predicted that 82.2% of interannual snow and ice storage in Wyoming may disappear by 2100 using temperature increases projected by CMIP5 GCMs, under the RCP4.5 emission scenario.
Author: Morgan Meertens Publisher: ISBN: Category : Climatic changes Languages : en Pages : 78
Book Description
The Budyko climate model is an energy balance model that considers how variations in radiative forcing affect the presence and growth of ice sheets on Earth. This conceptual model has three key terms representing energy received from the sun, energy re-radiated into space in the form of outgoing long-wave radiation and energy transport between latitudinal layers. Previously, an evolving ice line equation was coupled with the Budyko model and the behaviour of the resulting system was investigated. It was shown that this coupled climate model could be reduced to a single differential equation. In later work, a second slow-varying parameter representing CO2 concentration in the atmosphere was coupled with the reduced Budyko-ice line equation and the behaviour of this model in a physical setting was explored. It was found that small stable ice caps and large amplitude oscillations between ice-free and ice-covered climate regimes were possible attracting states for the system. We extend this work further by investigating the dynamics of the coupled Budyko-ice line-CO2 model upon the addition of an equation for a slowly varying silicate weathering parameter. An increase in silicate weathering rate is believed to have been a key reason for the Earth's climate system entering a completely glaciated state. We use geometric singular perturbation theory to determine how the behaviour depends on the dynamic silicate weathering related parameter. It was found that the speed at which silicate weathering rate increases determines the systems possible behaviour. Trajectories that remained indefinitely in an ice-free state with a constant silicate weathering rate are now capable of being reinjected into an ice cap regime. We also find that small amplitude oscillating ice caps before a snowball Earth event is a possibility.
Author: Avirup Sen Gupta Publisher: ISBN: Category : Languages : en Pages :
Book Description
The Hindu-Kush Himalayan region possesses a large resource of snow and ice, which acts as a freshwater reservoir for irrigation, domestic water consumption or hydroelectric power for billions of people in South Asia. Monitoring hydrologic resources in this region is challenging because of the difficulty of installing and maintaining a climate and hydrologic monitoring network, limited transportation and communication infrastructure and difficult access to glaciers. As a result of the high, rugged topographic relief, ground observations in the region are extremely sparse. Reanalysis data offer the potential to compensate for the data scarcity, which is a barrier in hydrological modeling and analysis for improving water resources management. Reanalysis weather data products integrate observations with atmospheric model physics to produce a spatially and temporally complete weather record in the post-satellite era. This dissertation creates an integrated hydrologic modeling system that tests whether streamflow prediction can be improved by taking advantage of the National Aeronautics and Space Administration (NASA) remote sensing and reanalysis weather data products in physically based energy balance snow melt and hydrologic models. This study also enhances the energy balance snowmelt model by adding capability to quantify glacier melt. The novelty of this integrated modeling tool resides in allowing the user to isolate various components of surface water inputs (rainfall, snow and glacier ice melt) in a cost-free, open source graphical-user interface-based system that can be used for government and institutional decision-making. Direct, physically based validation of this system is challenging due to the data scarcity in this region, but, to the extent possible, the model was validated through comparison to observed streamflow and to point measurements at locations in the United States having available data
Author: Thomas M. Mosier Publisher: ISBN: Category : Cryosphere Languages : en Pages : 242
Book Description
In many regions of the world, a significant portion of the surface water originates in mountain headwaters where the timing and magnitude of streamflow is largely dictated by the seasonal storage of precipitation as snowpack and long-term storage as glaciers. Accumulation, persistence, and melt of snow and ice are functions of the climate in which they exist and therefore respond to changes in that climate. One important use of water in many regions is for hydropower energy production. While reservoir-based hydropower infrastructure has some ability to absorb changes in timing of streamflow, run-of-river hydropower infrastructure does not. Thus, in assessing the economic feasibility of new or existing run-of-river infrastructure, it is important to account for potential impacts climate change may have over the lifetime of the project. Projecting impacts of climate change on surface water resources, and in particular on run-of-river hydropower resource potential, requires robustly characterizing the linkages between the climate, cryosphere, and streamflow. Two obstacles to increasing our understanding of mountain systems are the sparsity of observation data and complexity of weather patterns. The first part of my research addresses the issue of climate data availability in mountain regions through development of statistical models to characterize the high-spatial resolution distribution of historic and projected future precipitation and temperature. I demonstrate these climate products through projecting long-term changes in snowfall for the Alaska Range, Alps, Central Andes, and Himalaya-Karakoram-Hindu Kush ranges. I then present a framework for assessing conceptual cryosphere hydrology models and implement the framework for two long-term glacier study sites in Alaska, USA. Using this framework, I identify novel formulations for modeling the heat transfer and energy balance of snowpacks and glaciers that improve model robustness relative to the current generation of cryosphere hydrology models typically used in data-sparse mountain environments. I then demonstrate a method for understanding the impacts of projected future climate change on run-of-river hydropower resource potential, using Falls Creek in Oregon, USA as a test case. A core value of this work is producing models that can be straightforwardly applied to any region, thus decreasing the impacts of data disparities between regions on our ability to characterize climate change impacts on mountain regions.
Author: Hazel Arlette Reynolds Publisher: ISBN: Category : Languages : en Pages : 430
Book Description
Six glaciers in the Teton Range, Wyoming decreased in ice area from 1956-2010, with episodes of subdecadal-scale ice growth interrupting that trend. Periods of glacier growth include ca. 1974-1983 and 2006-2009. We compared ice area fluctuations to meteorological factors derived from the Parameter-elevation Regressions on Independent Slopes Model (PRISM). We used partial least squares regression analysis to determine statistical relationships between ice area change and meteorological fluctuations. Weather records were summarized as either seasons of water years or full water years (WY) and compared, in consecutive years, to ice area changes. We determined that spring precipitation and average annual temperature, averaged over four years, show the strongest correlation to glacier area change. Spring precipitation can affect growing glaciers by shortening the ablation season, adding mass, and providing clouds that reduce sun radiation and melting on the glacier surface. The opposite is true during dry springs, which correlate with smaller glacier area. The effect of spring precipitation on glacier area is dictated by the temperature of the precipitation at the glacier. We also found that the Teton glacier fluctuations do not clearly correspond with the El Niflo-Southern Oscillation index. We applied a two-dimensional numerical energy mass balance model to six of these glaciers. We conducted four tests with ten climate input files derived from PRISM and from weather station data, covering five time periods ranging in length from 1-54 water years. Using PRISM data output, the model failed to produce positive mass balance at the glaciers within observed weather conditions (WY 1956-2010). Using mean climatic variables from weather stations in the Teton Range (WY 1956-2010), the model also did not produce positive modeled mass balance. Climate data from the weather stations during short periods with lower temperatures and higher precipitation produced positive modeled mass balance at Falling Ice, Middle Triple, and West Triple glaciers. Of these short periods, only modeled mass balance in 1982-1985 at the Mt. Moran glacier complex agreed with glacier area observations. We suggest the model overestimates melt at these glaciers, possibly influenced by model inputs that incorporate too much lowelevation weather station data. More data from high elevation stations will create a better understanding of energy mass balance at these glaciers.
Author: Ryan J. Johnson
Author: Ryan J. Johnson
Author: Morgan Meertens
Author: Eric A. Anderson
Author: Lars Gottlieb
Author: Richard L. Armstrong
Author: Avirup Sen Gupta
Author: Ian M. Howat
Author: Thomas M. Mosier
Author: Hazel Arlette Reynolds
Author: Lisa Von der Heydt