Bergstrom, Anna听1听;听Gooseff, Michael听2
1听University of 蜜糖直播 - Boulder
2听University of 蜜糖直播 - Boulder
The Dry Valleys of Antarctica are a polar desert ecosystem consisting of alpine glaciers, ice-covered lakes, and vegetation-free rocky soil. The entire ecosystem is highly dependent on glacial melt a water source. Because average summer temperatures are close to 0 degrees C, glaciers as well as the rest of the valleys are very closely linked to the energy balance. A slight increase in incoming radiation or decrease in albedo can have large effects on the timing and volume of melt water. However, we have yet to fully characterize the seasonal evolution of albedo in the valleys. In this study, we used a camera, gps, and short wave radiometer to characterize the albedo within and across landscape types in the Taylor Valley. These instruments were attached to a helicopter and flown on a prescribed path along the valley at approximately 300 feet above the ground five different times throughout the field season in (November to January) in 2015-16 and 2016-17. We used these data to calculate the albedo of each glacier, lake, and the soil surface of the lake basins in the valley for each flight. As expected, we found that all landscape types had significantly different albedo, with the glaciers consistently the highest throughout the season and the bare soils the lowest (p-value < 0.05). We hypothesized that albedo would decrease throughout the season with snow melt and increasing sediment exposure on the glacier and lake surfaces. However, snow events caused somewhat persistent high albedo on the lakes and glaciers. Furthermore, there was a range in albedo across glaciers and each responded to seasonal snow and melt differently. These findings highlight the importance of understanding the spatial and temporal variability in albedo and the close coupling of climate and landscape response. We can use this new understanding of landscape albedo to better predict how the Dry Valley ecosystems will respond to changing climate at the basin scale.