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TitleValidation of the RACMO2.3 surface mass-balance model over northwest Devon Ice Cap, Nunavut
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AuthorBurgess, D O
SourceGeological Survey of Canada, Open File 8382, 2018, 19 pages, https://doi.org/10.4095/308355 (Open Access)
Image
Year2018
PublisherNatural Resources Canada
Documentopen file
Lang.English
Mediaon-line; digital
File formatpdf
ProvinceNunavut
NTS48H
AreaCanadian Arctic Archipelago; Devon Island; Devon Ice Cap
Lat/Long WENS -84.0000 -80.0000 76.0000 75.0000
Subjectsenvironmental geology; hydrogeology; Nature and Environment; glaciology; glaciers; ice; climate, arctic; models; runoff; surface waters; hydrologic environment; hydrologic budget; Regional Atmospheric Climate Model; mass balance; meltwater; fresh water; freshwater flux; monitoring; climate change
Illustrationsphotographs; location maps; satellite images; profiles; graphs; models; time series; bar graphs
ProgramGlacier Mass Balance Project, GSC Atlantic Division
Released2018 12 24
AbstractThe RACMO2.3 regional climate model has been validated against in-situ mass-balance measurements along the northwest Devon ice cap transect (herein after referred to as Devon(NW)) at annual, pentadal, and decadal time scales over the period spanning 2006 to 2015. Results show close agreement between Summer Balance measurements at the pentadal and decadal time scales, with a bias towards suppressed melt by ~200 mm w.e. in the RACMO2.3 data averaged over the entire transect (ie. 100 - 1800 m a.s.l.), and maximum biases to ~600 mm w.e. between 400 and 900 m a.s.l. Comparisons at the annual scale indicate greatest discrepancies for 2010 for which RACMO2.3 was up to 80 cm w.e. less negative than the in-situ values. Winter Balance in the RACMO2.3 data showed an inverse elevational trend relative to the in-situ values with an overall bias towards greater accumulation by ~120 mm w.e. along the entire transect. At the basin-wide scale, RACMO2.3 under (over) estimates of summer (winter) balance values combine to result in basin-wide estimates of net balance for the Devon (NW) basin to be 37% less negative than the in-situ measurements over the 2006-2015 period. Reasonable agreement with in-situ derived Summer Balance values indicates RACMO2.3 can provide estimates of seasonal freshwater flux to oceans close to and within error of the measurements. However, significant biases in the RACMO2.3 Net Annual Balance modeled values must be accounted for when estimating annual or multi-annual contributions to global sea-level rise from glaciers and ice caps in the Canadian high Arctic.
Summary(Plain Language Summary, not published)
Canada's Arctic glaciers lose ice mass primarily through surface melt runoff and ice-calving from tidewater terminating glaciers. Assessing the impacts of enhanced run-off from glaciers and ice caps in the Canadian Arctic requires knowledge of the broad-scale patterns of surface mass balance gained primarily through regional mass balance models. In this study, performance of the Regional Atmospheric Climate Model, or RACMO2.3, is validated through comparison with results from the NRCan in-situ glacier monitoring over the Devon Ice Cap (NW), Nunavut. Results from indicate that the RACMO2.3 regional mass balance model does provide reliable estimates of summer meltwater runoff from the Devon ice cap, but rather large biases in Net mass balance limits usefulness of this model for quantifying total contributions to global sea-level rise from glaciers and ice caps in the Canadian arctic.
GEOSCAN ID308355