Boundary-layer climate of the Darwin-Hatherton Glacial Syste

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TitleBoundary-layer climate of the Darwin-Hatherton Glacial System, Antarctica: Meso- and synoptic-scale circulationsAbstractThe Transantarctic Mountain (TAM) glaciers that border the Ross Ice Shelf are important for the Antarctic Ice Sheet mass balance, but little is known about their climate. This research presents a climatology of the Darwin-Hatherton Glacial System (DHGS). Measurements from the longest reliably functioning automatic weather station in the TAM south of 78^circ latitude (2005-2011, excluding 2009) are used to describe the boundary-layer climate. Identified mesoscale features, denoted as downslope, humid, stagnant and anabatic winds, are profiled in terms of their character and frequency. The influence of the synoptic circulation on the boundary layer is investigated by comparing mesoscale feature frequencies to a set of synoptic pressure maps produced from Polar Weather Research and Forecasting model simulations and the self-organizing maps algorithm. Between April and September, the boundary layer is dominated by strong, dry, cold downslope winds (80%) that continuously flush the DHGS boundary layer preventing cold pools from developing, as is common in the McMurdo Dry Valleys. Humid winds, occurring under a variety of synoptic circulations, irregularly interrupt downslope winds, elevating air temperatures and specific humidity. Downslope winds begin to abate in October in frequency (24%) and strength, and humid winds become dominant (67%). A portion of humid winds in summer are mesoscale anabatic winds (15%) occurring after morning periods of downslope winds, and frequently under synoptic circulations whose pressure gradient is parallel to the TAM. The remaining 52% of humid winds generally persist for a day to multiple days, occurring more commonly under synoptic circulations whose pressure gradients are slack. The speed of downslope winds is influenced by synoptic circulation pressure gradient and orientation. The climate is similar to the Mulock Glacier, particularly from February to November. Changes to the synoptic circulation will impact the climate of these glaciers and their surface mass balance. â"' 2015 Royal Meteorological Society.AcknowledgementsWe wish to thank Antarctica New Zealand, the Christchurch City Council and Helicopters New Zealand for funding this research. We appreciate the open access to AWS data. BH and LD AWS data sets were obtained through the Latitudinal Gradient Project website (http://www.lgp.aq/), and non-DHGS data sets from the University of Wisconsin-Madison Automatic Weather Station Program, NSF grant numbers ANT-0944018 and ANT-1245663. We thank the Polar Meteorology Group at Byrd Polar Research Centre for supplying Polar-WRF source code, and the Helsinki University of Technology for access to SOM_PAK code. We wish to credit NASA LP DAAC for ASTER GDEM data, a product of METI and NASA and Pascal Sirguey for the DHGS DEM. We wish to thank I. Owens, D. Reusch, and J. Cassano for their opinions and assistance, and the reviewers whose comments have improved this manuscript.

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1st AuthorNoonan, B.AuthorNoonan, B.Zawar-Reza, P.Lawson, W.Year2015JournalInternational Journal of ClimatologyVolume35Number12Pages3608-3623DOI10.1002/joc.4235URLhttps://www.scopus.com/inward/recor.....e39cd07b38770dfbc86b299f7KeywordsConformal mappingGlacial geologyLandformsPressure gradientSelf organizing mapsWeather forecastingWeather information servicesWind, AnabaticAntarcticaDarwin-HathertonKatabaticPolar WRFTransantarctic Mountains, Boundary layers, atmospheric circulationboundary layerclimate effectclimatologycomputer simulationglacier dynamicskatabatic flowmass balancemesoscale meteorologysynoptic meteorologyweather forecastingwind velocity, AntarcticaRoss Ice ShelfTransantarctic MountainsWest Antarctica, rank5Author KeywordsAnabaticAntarcticaByrd GlacierDarwin-HathertonKatabaticPolar WRFSelf-organizing mapsTransantarctic Mountains

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TypeArticleCitationNoonan, B., Zawar-Reza, P. and Lawson, W. (2015) Boundary-layer climate of the Darwin-Hatherton Glacial System, Antarctica: Meso- and synoptic-scale circulations. International Journal of Climatology, 35(12): 3608-3623 doi:10.1002/joc.4235 IdentifierNoonan2015Relevancerank5