|Essery, Richard -|
|Marsh, Phil -|
Submitted to: Hydrological Processes
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 15, 2009
Publication Date: August 15, 2009
Citation: Essery, R., D. Marks and P. Marsh, 2009. Preface: Sub-surface, Surface and Atmospheric Processes in Cold Regions Hydrology, Hydrological Processes, 23(1-2):2496–2497, doi: 10.1002/hyp.7365 Interpretive Summary: This is the preface to a special section of four papers from three sessions at the 24th General Assembly of the International Union of Geodesy and Geophysics (IUGG), held in Perugia, Italy, in July 2007: ‘Interactions between snow, vegetation and the atmosphere’, ‘Hydrology in mountain regions’ and ‘Climate-permafrost-hydrology interactions’. The papers are “The summer hydrology of a small upland tundra thaw lake: implications to lake drainage”, by S. Pohl, P. Marsh, C. Onclin and M. Russell, “The impact of coniferous forest temperature on incoming longwave radiation to melting snow”, by J. Pomeroy, D. Marks, T. Link, C. Ellis, J. Hardy, A. Rowlands and R. Granger, “An efficient method for distributing wind speeds over heterogeneous terrain”, by A. Winstral, D. Marks and R. Gurney, and “The role of snow interception in winter-time radiation processes of a coniferous sub-alpine forest”, by Stahli M, Jonas T, Gustafsson.
Technical Abstract: This special section presents papers from three sessions at the 24th General Assembly of the International Union of Geodesy and Geophysics (IUGG), held in Perugia, Italy, in July 2007: ‘Interactions between snow, vegetation and the atmosphere’, ‘Hydrology in mountain regions’ and ‘Climate-permafrost-hydrology interactions’. In total, 140 abstracts were submitted for these three sessions, so the four papers published here only represent a very small sample. Two of the papers (Stahli et al. and Pomeroy et al.) deal with measurements and modelling of radiative fluxes to snow underneath forest canopies. Stahli et al. used a rail-mounted radiometer system to measure the highly variable sub-canopy radiation, finding that intercepted snow increases the canopy albedo and the transmission of shortwave radiation, although solar elevation and the fraction of diffuse radiation have stronger influences on transmissivity. Pomeroy et al. used arrays of radiometers to measure sub-canopy radiation and both narrow-beam radiometers and thermocouples to measure canopy temperatures at sites in Colorado and Alberta. Focusing on longwave radiation, they found that sunlit trunks can be substantially warmer than the air, leading to enhanced longwave radiation to snow under the canopy in periods of high insolation; they suggest that methods for estimating longwave radiation that account for the absorption of shortwave radiation by canopies will be more accurate than methods that merely use air temperature and sky view. Winstral et al. present an efficient method for calculating wind speed variations over complex terrain for determining snow distributions, evaluating the model in comparison with measurements at sites in Idaho and northern Canada. Pohl et al. consider the phenomenon of rapid drainage of tundra thaw lakes; they suggest that, although high lake levels are a contributing factor for rapid lake drainage, warm and wet summer conditions predicted to occur more frequently in the Arctic greatly increase the likelihood of rapid drainage events.