Solar Radiation and Air and Ground Temperature Relations in the Cold and Hyper‐Arid Quartermain Mountains, McMurdo Dry Valleys of Antarctica

Abstract

This study compares the relations between solar radiation and air and ground temperatures in the Quartermain Mountains of the McMurdo Dry Valleys of Antarctica with those in ice‐free Victoria Land and Arctic Canada. The surface offset is near 0°C at all sites in the Quartermain Mountains and other sites in coastal Victoria Land, whereas the thermal offset is near 0°C at shallow ice table depths (< 20 cm) and near 1°C for ice tables deeper than the depth of diurnal temperature variation. The surface and thermal offsets in Victoria Land differ markedly from those in Arctic Canada, which are generally characterised by a positive surface offset and a negative thermal offset. These important differences highlight the effects of a lack of vegetation, surface organic layer, snow cover and moisture content in near‐surface soils on the direction and magnitude of surface and thermal offsets. Summer ground surface temperatures in the Quartermain Mountains correlate strongly with incoming solar radiation. Based on measured ground surface temperatures and modelled potential incoming solar radiation, two zones with distinct ground surface temperatures are defined in the Quartermain Mountains: (i) perennially cryotic zones (PCZs) characterised by ground surface temperatures always below 0°C; and (ii) seasonally non‐cryotic zones (NCZs) characterised by ground surface temperatures > 0°C for at least a few hours. Soils in the PCZs experience water exchange through vapour diffusion, whereas soils in the NCZs contain features associated with liquid water activity, such as increased soil moisture and frozen ponds recharged by snow/glacier meltwater. Copyright © 2015 John Wiley & Sons, Ltd.

Physicochemical and Biological Controls on Carbon and Nitrogen in Permafrost from an Ultraxerous Environment, McMurdo Dry Valleys of Antarctica

“…(a) Hillshade showing location of University Valley in the Quartermain Mountains of Antarctica; (b) map showing ground surface temperature zones of University Valley and location of 12 polygons (from Lacelle et al, ). The hillshade image was derived from a LiDAR digital elevation model ( http://usarc.usgs.gov/lida_dload.shtml) embedded into a 15 m ASTER digital elevation model ( http://asterweb.jpl.nasa.gov/data/asp).…”

“…Three years of climate data (2010–2012) collected from an automated weather station in University Valley indicated a mean annual air temperature of −23.4 ± 0.9°C, a mean annual relative humidity of 45.5 ± 1.8%, and maximum hourly air temperatures always <0°C (Lacelle et al, ), typical conditions in the stable upland climate zone of the MDV (Doran et al, ; Marchant & Head, ). Two distinct ground surface temperature zones have been identified in the valley as a result of topographic shadowing: (1) a perennially cryotic zone (PCZ) in the north‐east section of the valley, characterized by ground surface temperatures always <0°C and little to no presence of liquid water; and (2) a seasonally noncryotic zone (NCZ), characterized by ground surface temperatures that rise above 0°C for at least a few hours on clear summer days and where liquid water can exists as snow meltwater (Figure e).…”

Cryostratigraphy and the Sublimation Unconformity in Permafrost from an Ultraxerous Environment, University Valley, McMurdo Dry Valleys of Antarctica

“…(D) Photograph illustrating snow in the troughs of sand‐wedge polygons in University Valley. (E) Map showing the ground surface temperature zones in University Valley and the location of the four polygons analysed in this study (from Lacelle et al, ). The hillshades were derived from a LiDAR digital elevation model (usarc.…”

“…University Valley is situated in the stable upland climate zone of the MDV, a region characterised by summer air temperatures <0°C, relative humidity values near 50 per cent (Doran et al, ; Marchant and Head, ) and low precipitation (<10 mm snow water equivalent; Fountain et al, ). Three years of climate data (2010–12) collected from an automated weather station in University Valley indicated a mean annual air temperature of −23.4 ± 0.9°C, a mean annual relative humidity of 45.5 ± 1.8 per cent and maximum hourly air temperatures always <0°C (Lacelle et al, ). Two distinct ground‐surface temperature zones have been identified in the valley (Figure e): (1) a perennially cryotic zone (PCZ) in the northeast section of the valley, characterised by ground‐surface temperatures always <0°C; and (2) a seasonally non‐cryotic zone (NCZ), characterised by ground‐surface temperatures that rise above 0°C for at least a few hours on clear summer days.…”

“…The permafrost table along the floor of University Valley is at the ground surface (Lacelle et al, ), whereas the ice table ranges in depth from 0 cm near the glacier to ca. 60 cm at the mouth of the valley (McKay, ; Marinova et al, ).…”