Synoptic Climate Controls of Mass-Balance Variations on Devon Island Ice Cap

Alt, B T

doi:10.2307/1550657

Cited by 47 publications

(45 citation statements)

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“…With a melting surface (lower albedo) and clear skies, again with light winds, R attained much higher values. Similar relationships were found by Alt (1978) on the Meighen Ice Cap (N.W.T., Canada). Table VI shows that with a high surface albedo, R nearly triples from low to high cloud-cover conditions (a to c).…”

Section: Discussionsupporting

confidence: 75%

Radiation and Cloud Observations on a High Arctic Plateau Ice Cap

Bradley

1987

J. Glaciol.

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ABSTRACT.Hourly measurements of incoming short-wave and long-wave radiation, surface albedo, and net radiation were made on and around a plateau ice cap on north-eastern Ellesmere Island during the summers of 1982 and 1983. These data were stratified by cloud type and amount. All cloud types increased incoming long-wave radiation, especially low dense clouds, fog, and clouds associated with snowfall. Relative transmission of incoming short-wave radiation, expressed as a percentage of clear-sky radiation receipts, was high for all cloud types compared to clouds at lower latitudes. With high surface albedo (~0.75), net radiation was strongly and positively correlated with net long-wave radiation but showed little relationship to net short-wave radiation. By contrast, with low surface albedo «(0.20) net radiation was negatively correlated with net long-wave radiation but positively correlated with net shortwave radiation. Under high-albedo conditions, an increase in cloudiness led to higher values of net radiation but under low-albedo conditions net radiation decreased as cloud cover increased. Survival of a snow cover would seem to be favoured if the seasonal decline in albedo is accompanied by a corresponding increase in cloudiness.

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Section: Discussionsupporting

confidence: 75%

Radiation and Cloud Observations on a High Arctic Plateau Ice Cap

Bradley

1987

J. Glaciol.

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“…2), was −3.3 ± 1.8°C (mean ± 1 SD; Table 1 (Rajewicz and Marshall, 2014;Bezeau and others, 2015). Such synoptic conditions have previously been linked with extreme warm summers and negative glacier mass balances in the QEI (Alt, 1978(Alt, , 1987Gascon and others, 2013a). The 500 hPa geopotential height anomalies for 2000-15 from NCEP/NCAR Reanalysis R1 data (Kalnay and others, 1996) display a ridge (trough) centered over the north and west of the QEI during warm (cold) summers.…”

Section: Mean Summer Glacier Lstmentioning

confidence: 77%

Glacier surface temperatures in the Canadian High Arctic, 2000–15

2016

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ABSTRACT. Canada's Queen Elizabeth Islands (QEI) contain ∼14% of the world's glacier and ice-cap area. Sparse in-situ measurements indicate that interannual variability in glacier surface mass balance in this region is driven primarily by variations in summer melt, and that the annual surface mass balance of four index glaciers has become increasingly negative since 2007. Here, we use a 16-a record of satellite-derived mean summer (June-August) land surface temperatures (LST) from NASA's Moderate Resolution Imaging Spectroradiometer to investigate large-scale spatial and temporal variability in the duration and intensity of summer melt across glaciated surfaces in the QEI from 2000 to 2015. During this period, QEI mean summer glacier surface temperatures increased at an average rate of 0.06 ± 0.04°C a

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“…Summer months are characterized by weakened cyclonic strength and increased frequency of anticyclonic systems (ξ JJA = 2.3 × 10 −5 s −1 ) as the winter vortex weakens over the region and high-pressure ridges penetrate intermittently to the latitude of the Queen Elizabeth Islands (e.g. Bradley and England, 1979;Alt, 1978Alt, , 1987.…”

Section: Mean Flow Conditions In the Regionmentioning

confidence: 99%

Near‐surface‐temperature lapse rates on the Prince of Wales Icefield, Ellesmere Island, Canada: implications for regional downscaling of temperature

Marshall

Sharp

Burgess

et al. 2006

Intl Journal of Climatology

147

164

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Abstract:Screen temperatures were monitored from May 2001 to April 2003 in an array of 25 sites on the Prince of Wales Icefield, Ellesmere Island, Canada. The observational network covered an area of ca 15 650 km 2 and spanned an altitude ranging from 130 to 2010 m above sea level. The spatial array provides a record of near-surface-temperature lapse rates and mesoscale temperature variability on the icefield. The mean daily lapse rate in the 2-year record is −4.1°C km −1 , with an average summer lapse rate of −4.3°C km −1 . Surface-temperature lapse rates in the region are therefore systematically less than the free-air lapse rates that are typically adopted for extrapolations of sea-level temperature to higher altitudes. Steep lapse rates, resembling moist adiabatic rates in the free air (−6 to −7°C km −1 ), are more common in summer at our site and are associated with enhanced cyclonic activity (low-pressure and high relative vorticity) and southerly flow aloft. In contrast, northerly, anticyclonic flow prevails when summer lapse rates are weak (above −2°C km −1 ). The low surface-temperature lapse rates and their systematic synoptic variability have important implications for applications that require downscaling or extrapolation of surface-or boundary-layer temperatures, such as modelling of glacier mass balance. We illustrate this in an analysis of observed versus modelled snowmelt on the icefield.

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Synoptic Climate Controls of Mass-Balance Variations on Devon Island Ice Cap

Cited by 47 publications

References 1 publication

Radiation and Cloud Observations on a High Arctic Plateau Ice Cap

Radiation and Cloud Observations on a High Arctic Plateau Ice Cap

Glacier surface temperatures in the Canadian High Arctic, 2000–15

Near‐surface‐temperature lapse rates on the Prince of Wales Icefield, Ellesmere Island, Canada: implications for regional downscaling of temperature

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