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• 1. [Image] Arlington, Ore. Jan. 12, 1909, 20 below zero. Columbia River Frozen over, The first time in 24 years.

  	A view of the Columbia River shore at Arlington, Oregon, on January 12, 1909. The Columbia River is frozen. In the foreground is the white riverbank, with a large boulder to the left. Near the shore on ...
  	Citation × Citation Citation Abstract Copy Title: Arlington, Ore. Jan. 12, 1909, 20 below zero. Columbia River Frozen over, The first time in 24 years. A view of the Columbia River shore at Arlington, Oregon, on January 12, 1909. The Columbia River is frozen. In the foreground is the white riverbank, with a large boulder to the left. Near the shore on the right of the photo is a pier, with a sailboat at its end. In the center we see a stern-wheeler. A long rope leads out from it and is coiled on the frozen river. A group of five men stand nearby, close to a rectangular area of water that has been freed of ice. Their attention is on a sixth man who is standing in a rowboat pushing at the ice with a long pole. One of the group on the river also carries a long pole. The writing on the photograph says the temperature is 20 below zero and the first time in 24 years the river had frozen over. Title: Arlington, Ore. Jan. 12, 1909, 20 below zero. Columbia River Frozen over, The first time in 24 years. A view of the Columbia River shore at Arlington, Oregon, on January 12, 1909. The Columbia River is frozen. In the foreground is the white riverbank, with a large boulder to the left. Near the shore on the right of the photo is a pier, with a sailboat at its end. In the center we see a stern-wheeler. A long rope leads out from it and is coiled on the frozen river. A group of five men stand nearby, close to a rectangular area of water that has been freed of ice. Their attention is on a sixth man who is standing in a rowboat pushing at the ice with a long pole. One of the group on the river also carries a long pole. The writing on the photograph says the temperature is 20 below zero and the first time in 24 years the river had frozen over. Close

• 2. [Image] Arlington, Ore. Jan. 12, 1909, 20 below zero. Columbia River Frozen over, The first time in 24 years.

  	A view of the Columbia River shore at Arlington, Oregon, on January 12, 1909. The Columbia River is frozen. In the foreground is the white riverbank, with a large boulder to the left. Near the shore on ...
  	Citation × Citation Citation Abstract Copy Title: Arlington, Ore. Jan. 12, 1909, 20 below zero. Columbia River Frozen over, The first time in 24 years. A view of the Columbia River shore at Arlington, Oregon, on January 12, 1909. The Columbia River is frozen. In the foreground is the white riverbank, with a large boulder to the left. Near the shore on the right of the photo is a pier, with a sailboat at its end. In the center we see a stern-wheeler. A long rope leads out from it and is coiled on the frozen river. A group of five men stand nearby, close to a rectangular area of water that has been freed of ice. Their attention is on a sixth man who is standing in a rowboat pushing at the ice with a long pole. One of the group on the river also carries a long pole. The writing on the photograph says the temperature is 20 below zero and the first time in 24 years the river had frozen over. Title: Arlington, Ore. Jan. 12, 1909, 20 below zero. Columbia River Frozen over, The first time in 24 years. A view of the Columbia River shore at Arlington, Oregon, on January 12, 1909. The Columbia River is frozen. In the foreground is the white riverbank, with a large boulder to the left. Near the shore on the right of the photo is a pier, with a sailboat at its end. In the center we see a stern-wheeler. A long rope leads out from it and is coiled on the frozen river. A group of five men stand nearby, close to a rectangular area of water that has been freed of ice. Their attention is on a sixth man who is standing in a rowboat pushing at the ice with a long pole. One of the group on the river also carries a long pole. The writing on the photograph says the temperature is 20 below zero and the first time in 24 years the river had frozen over. Close

• 3. [Article] Modeling Arctic melt ponds using a resolved ice model with GCM forcing

  The albedo of Arctic sea ice depends greatly on the formation of melt ponds. These ponds form in depressions on the ice as surface snow melts during the summer months, and their location is determined ...

  Citation × Citation Citation Abstract Copy Title: Modeling Arctic melt ponds using a resolved ice model with GCM forcing Author: Collins, Lee E. The albedo of Arctic sea ice depends greatly on the formation of melt ponds. These ponds form in depressions on the ice as surface snow melts during the summer months, and their location is determined mainly by the initial snow topography. Using a high resolution sea ice model forced with data taken from the Atmospheric Radiation Measurement (ARM) site in Barrow, AK, we investigate how specific factors, both internal model parameters and initial conditions, affect the evolution of melt ponds on Arctic sea ice. We also use forcing data taken from output of the Community Earth Systems Model (CESM) to investigate the differences in melt pond parametrization between our model and CESM. The resolved model uses a unique and innovative approach in pond modeling, the trigger depth method, to initiate pond drainage. Results from sensitivity analysis on the trigger depth show the validity of this new approach, suggesting it could be useful in other ice models. The initial snowpack has a very large role in pond formation and extent. We use surface topography gathered from LiDAR scans from the ARM site to provide a realistic snowpack surface. For our sensitivity analysis of the total initial amount of snow in the model, we alter only the minimum thickness of the snow on top of the ice, retaining a consistent surface topography for each simulation. The LiDAR topography from the ARM site provides a more realistic approach to the pond model, as opposed to a randomly generated method of creating snow topography. Large initial snowpack inhibits the formation of deep channels in the ice, reducing pond fraction at the end of the melt season. Finally, we force the resolved model simulations with data from CESM and compare the pond behavior to that of CESM. CESM does an unrealistic job of representing melt ponds, partially due to the way melt ponds are parametrized in the model, using a thickness-class method for creating and categorizing melt ponds. CESM pond formation occurs over a much broader time span compared to observations and our resolved model. Results from this work will be used to investigate and possibly improve the melt pond parametrization in CESM. Title: Modeling Arctic melt ponds using a resolved ice model with GCM forcing Author: Collins, Lee E. The albedo of Arctic sea ice depends greatly on the formation of melt ponds. These ponds form in depressions on the ice as surface snow melts during the summer months, and their location is determined mainly by the initial snow topography. Using a high resolution sea ice model forced with data taken from the Atmospheric Radiation Measurement (ARM) site in Barrow, AK, we investigate how specific factors, both internal model parameters and initial conditions, affect the evolution of melt ponds on Arctic sea ice. We also use forcing data taken from output of the Community Earth Systems Model (CESM) to investigate the differences in melt pond parametrization between our model and CESM. The resolved model uses a unique and innovative approach in pond modeling, the trigger depth method, to initiate pond drainage. Results from sensitivity analysis on the trigger depth show the validity of this new approach, suggesting it could be useful in other ice models. The initial snowpack has a very large role in pond formation and extent. We use surface topography gathered from LiDAR scans from the ARM site to provide a realistic snowpack surface. For our sensitivity analysis of the total initial amount of snow in the model, we alter only the minimum thickness of the snow on top of the ice, retaining a consistent surface topography for each simulation. The LiDAR topography from the ARM site provides a more realistic approach to the pond model, as opposed to a randomly generated method of creating snow topography. Large initial snowpack inhibits the formation of deep channels in the ice, reducing pond fraction at the end of the melt season. Finally, we force the resolved model simulations with data from CESM and compare the pond behavior to that of CESM. CESM does an unrealistic job of representing melt ponds, partially due to the way melt ponds are parametrized in the model, using a thickness-class method for creating and categorizing melt ponds. CESM pond formation occurs over a much broader time span compared to observations and our resolved model. Results from this work will be used to investigate and possibly improve the melt pond parametrization in CESM. Close