English
 
Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
Add to Basket
  Local TagsRelease HistoryDetailsSummary

Released
Conference Paper

Improving canopy-snow unloading parameterizations by including observed interactions between meteorological variables

Authors

Lumbrazo,  Cassie
IUGG 2023, General Assemblies, 1 General, International Union of Geodesy and Geophysics (IUGG), External Organizations;

Bennett,  Andrew
IUGG 2023, General Assemblies, 1 General, International Union of Geodesy and Geophysics (IUGG), External Organizations;

Webster,  Clare
IUGG 2023, General Assemblies, 1 General, International Union of Geodesy and Geophysics (IUGG), External Organizations;

Mazzotti,  Giulia
IUGG 2023, General Assemblies, 1 General, International Union of Geodesy and Geophysics (IUGG), External Organizations;

Malle,  Johanna
IUGG 2023, General Assemblies, 1 General, International Union of Geodesy and Geophysics (IUGG), External Organizations;

Haagmans,  Vincent
IUGG 2023, General Assemblies, 1 General, International Union of Geodesy and Geophysics (IUGG), External Organizations;

Jonas,  Tobias
IUGG 2023, General Assemblies, 1 General, International Union of Geodesy and Geophysics (IUGG), External Organizations;

Lundquist,  Jessica
IUGG 2023, General Assemblies, 1 General, International Union of Geodesy and Geophysics (IUGG), External Organizations;

External Ressource
No external resources are shared
Fulltext (public)
There are no public fulltexts stored in GFZpublic
Supplementary Material (public)
There is no public supplementary material available
Citation

Lumbrazo, C., Bennett, A., Webster, C., Mazzotti, G., Malle, J., Haagmans, V., Jonas, T., Lundquist, J. (2023): Improving canopy-snow unloading parameterizations by including observed interactions between meteorological variables, XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) (Berlin 2023).
https://doi.org/10.57757/IUGG23-4810


Cite as: https://gfzpublic.gfz-potsdam.de/pubman/item/item_5021216
Abstract
Interception of snow by trees is the dominant control on snow accumulation patterns in forest environments but is notoriously difficult to observe and model. In this work, we use time-lapse photography to create a timeseries of snow unloading to link with local meteorological measurements to better understand how snow unloads from the canopy. Our results support previous studies that air temperature drives unloading when temperatures are above 0 ºC. However, we found that below 0°C multiple variables interact when unloading occurs. For example, unloading occurs when shortwave radiation exceeds 400 Wm-2 for at least one hour, even while air temperatures remain negative. While it is well known that shortwave radiation heats canopy elements, it is rarely included in unloading parameterizations. Additionally, when air temperatures were below -3ºC, wind speeds as low as 2 to 4 ms-1 could unload snow, but wind speeds greater than 5 ms-1 were needed when temperatures were warmer than -3ºC. This can be explained by the greater cohesivity of snow at temperatures above -3ºC. The concept of snow cohesion changing with temperature is often included in the loading aspect of models, but not considered in the unloading counterpart. As a result of these observations, we adapted existing unloading parameterizations to account for the relationships between air temperature, wind speed, and incoming solar radiation statistically. We present model results demonstrating the impact of incorporating variable interactions in the Structure for Unifying Multiple Modelling Alternatives (SUMMA) modular hydrologic modelling framework.