School of Agriculture and Environment, University of Western Australia, Perth, 6009, Australia
Abstract. Synoptic weather patterns and teleconnection relationships across a 39 year climatology are investigated for their impact on energy fluxes driving ablation of a marginal snowpack in the Snowy Mountains, southeast Australia. K-means clustering applied to ECMWF ERA-Interim data identified common synoptic types and patterns that were then associated with in-situ snowpack energy flux measurements. The analysis showed that the largest contribution of energy to the snowpack occurred immediately prior to the passage of cold fronts through increased sensible heat flux as a result of warm air advection (WAA) ahead of the front. Indian Ocean Dipole and Southern Oscillation Index phase combination had a strong relationship with energy flux, with eight of the ten highest annual snowpack energy fluxes occurring during a negative IOD phase and positive SOI phase. Overall, seasonal snowpack energy flux over the 39 year period had a decreasing trend that is likely due to a reduction in the number of precipitation generating cold fronts and associated preceding WAA ahead of precipitation. This research is an important step towards understanding changes in surface energy flux as a result of shifts to the global atmospheric circulation as anthropogenic climate change continues.
How to cite. Schwartz, A., McGowan, H., Theobald, A., and Callow, N.: Quantifying the impact of synoptic weather types, patterns,
and trends on energy fluxes of a marginal snowpack, The Cryosphere Discuss. [preprint], https://doi.org/10.5194/tc-2019-48, 2019.
Received: 08 Mar 2019 – Discussion started: 08 Apr 2019
Understanding the relationship between weather and snowmelt is increasingly important as snowpacks undergo reductions due to climate change. Impacts of weather patterns on snowmelt in Australia's Snowy Mountains were identified through the use of weather pattern data and in-situ energy measurements. We found that maximum snowmelt occurs prior to the passage of cold fronts, teleconnections have an impact on snowmelt, and energy available for snowmelt has decreased slightly in the last 39 years.
Understanding the relationship between weather and snowmelt is increasingly important as...