Matt MacDonald School of GeoSciences, University of Edinburgh [email protected]John Pomeroy 1 , Richard Essery 2 , Al Pietroniro 3 1 Centre for Hydrology, University of Saskatchewan 2 School of Geosciences, University of Edinburgh 3 Meteorological Service of Canada, Environment Canada
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Matt MacDonald School of GeoSciences, University of ... - EC Workshop... · Matt MacDonald . School of GeoSciences, University of Edinburgh [email protected] . John Pomeroy
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Matt MacDonald School of GeoSciences, University of Edinburgh [email protected] John Pomeroy1, Richard Essery2, Al Pietroniro3
1 Centre for Hydrology, University of Saskatchewan 2 School of Geosciences, University of Edinburgh 3 Meteorological Service of Canada, Environment Canada
1) Evaluate simulations of snow transport, sublimation, accumulation, melt and infiltration to frozen soils using CLASS in a variety of windswept cold regions
2) Examine possible model improvements from additions of blowing snow transport and sublimation algorithms.
3) Examine possible model improvements from changes to turbulent transfer, snowcover depletion, snow densification, albedo decay, thermal conductivity, meltwater and frozen soil parameterisations.
Inter-tile and inter-grid square snow redistribution
QS
QS
QT
QT
TOPOGRAPHICDEPRESSION
WINDWARD
LEEWARD
GRASS FORESTBAREGROUND
SHRUB
QS
QT
WINDWARD,BARE GROUND,
GRASS
LEEWARD,FOREST
SHRUB,DEPRESSIONBLOWING SNOW
BLOWING SNOW
BLOW
ING
SNOW
IF CAPACITY/THRESHOLDIS EXCEEDED
QS
QS
QT
QT
TOPOGRAPHICDEPRESSION
WINDWARD
LEEWARD
GRASS FORESTBAREGROUND
SHRUB
QS
QT
QS
QS
QT
QT
TOPOGRAPHICDEPRESSION
WINDWARD
LEEWARD
GRASS FORESTBAREGROUND
SHRUB
QS
QT
WINDWARD,BARE GROUND,
GRASS
LEEWARD,FOREST
SHRUB,DEPRESSION
WINDWARD,BARE GROUND,
GRASS
LEEWARD,FOREST
SHRUB,DEPRESSIONBLOWING SNOW
BLOWING SNOW
BLOW
ING
SNOW
BLOWING SNOW
BLOWING SNOW
BLOW
ING
SNOW
IF CAPACITY/THRESHOLDIS EXCEEDED
Prairie Blowing Snow Model (PBSM) Pomeroy and Li (2000) numerically-integrated, fully-
developed snow transport and sublimation calculation modified for developing flow (Pomeroy et al., 2007)
Snow mass balance for a landscape unit j:
j
jnettj
s
j
lq
qPdt
dS ,+−=P: Snowfall rate (kg/s/m2) qs
j: Blowing snow sublimation (kg/s/m2) qt,net
j: Net snow transport into j (kg/s/m) lj: length of landscape unit in wind
direction (m)
Rocky Mountains
Prairies
Arctic
Boreal Forest
Sub-arctic
A network of WECC Observatories combine meteorological, hydrological, ecosystem, and cryospheric observations with multi-scale coupled models from the surface to the atmosphere.
Marmot Creek Research Basin Fisera Ridge
Wolf Creek Research Basin Granger Basin
Rocky Mountains Kananaskis Country
~2310 m ASL
Alpine tundra ridge just above treeline
200 m transect (snow surveys performed)
3 meteorological stations
15 km South of Whitehorse
1310-2100 m ASL 8 km2
Subarctic tundra cordillera
5 meteorological stations
PBSM coded into MESH inter-tile snow
redistribution
Single column tests at Fisera Ridge Windswept Winters 2007/2008 &
2008/2009 Three models PBSM + Snobal (CRHM) CLASS (calibrated) CLASS-PBSM (calibrated)
PBSM and Frozen Soil Infiltration parameterisations improve or do not degrade CLASS simulations in windswept cold regions environments
Varied changes to turbulent transfer, albedo, snow cover depletion, snow densification and thermal conductivity algorithms did not consistently improve CLASS performance
Concern that single snow layer in CLASS limits potential for improved simulation