Snowfall was measured at 11 sites in the McMurdo Dry Valleys to determine its magnitude, its temporal changes, and spatial patterns. Annual values ranged from 3 to 50 mm water equivalent with the highest values nearest the coast and decreasing inland. A particularly strong spatial gradient exists in Taylor Valley, probably resulting from local uplift conditions at the coastal margin and valley topography that limits migration inland. More snow occurs in winter near the coast, whereas inland no seasonal pattern is discernable. This may be due, again, to local uplift conditions, which are common in winter. We find no influence of the distance to the sea ice edge. Katabatic winds play an important role in transporting snow to the valley bottoms and essentially double the precipitation. That much of the snow accumulation sublimates prior to making a hydrologic contribution underscores the notion that the McMurdo Dry Valleys are indeed an extreme polar desert. Copyright © 2009 Royal Meteorological Society

© 1999 American Institute of Biological Sciences.Most of Antarctica is covered by ice that may exceed 3000 m in depth, but some areas of the continent are ice free. The McMurdo Dry Valleys, at 76°30′−78°30′ S, 160–164° E, form the largest (approximately 4800 km2) of the ice-free areas. This location has also been a US National Science Foundation (NSF)-funded Long-Term Ecological Research (LTER) site since 1993. The dry valleys are among the most extreme deserts on the planet, far colder and drier than deserts elsewhere. Mean annual temperatures in Taylor Valley (primary location of the McMurdo LTER) range from −16 °C to −21 °C, and precipitation is less than 10 cm annually. The dry valleys contain perennially ice-covered lakes, ephemeral streams, glaciers, and extensive areas of both soils and exposed bedrock. Despite these extreme climatic conditions, biological communities exist in the lakes, streams, and soils. These communities...

Mountain glaciers integrate climate processes to provide an unmatched signal of regional climate forcing. However, extracting the climate signal via intercomparison of regional glacier mass-balance records can be problematic when methods for extrapolating and calibrating direct glaciological measurements are mixed or inconsistent. To address this problem, we reanalyzed and compared long-term mass-balance records from the US Geological Survey Benchmark Glaciers. These five glaciers span maritime and continental climate regimes of the western United States and Alaska. Each glacier exhibits cumulative mass loss since the mid-20th century, with average rates ranging from −0.58 to −0.30 m w.e. a⁻¹. We produced a set of solutions using different extrapolation and calibration methods to inform uncertainty estimates, which range from 0.22 to 0.44 m w.e. a⁻¹. Mass losses are primarily driven by increasing summer warming. Continentality exerts a stronger control on mass loss than latitude. Similar to elevation, topographic shading, snow redistribution and glacier surface features often exert important mass-balance controls. The reanalysis underscores the value of geodetic calibration to resolve mass-balance magnitude, as well as the irreplaceable value of direct measurements in contributing to the process-based understanding of glacier mass balance.

The weather of the McMurdo Dry Valleys, Antarctica, the largest ice‐free region of the Antarctica, has been continuously monitored since 1985 with currently 14 operational meteorological stations distributed throughout the valleys. Because climate is based on a 30‐year record of weather, this is the first study to truly define the contemporary climate of the McMurdo Dry Valleys. Mean air temperature and solar radiation based on all stations were −20°C and 102 W m⁻², respectively. Depending on the site location, the mean annual air temperatures on the valleys floors ranged between −15°C and −30°C, and mean annual solar radiation varied between 72 and 122 W m⁻². Surface air temperature decreased by 0.7°C per decade from 1986 to 2006 at Lake Hoare station (longest continuous record), after which the record is highly variable with no trend. All stations with sufficiently long records showed similar trend shifts in 2005 ±1 year. Summer is defined as November through February, using a physically based process: up‐valley warming from the coast associated with a change in atmospheric stability.