Research interests, Research topics, CV, Projects, Publications
While the large-scale climate conditions play an important role in shaping the environment in which glaciers exist, the mass and energy balance of each individual glacier is dictated by local conditions. Given the complex mountain topography around alpine glaciers, it is not trivial to find a direct link between the large-scale atmospheric motions and the local-scale weather conditions at an individual glacier, or even at a given point on the glacier. To understand this link we need a profound knowledge of the mutual interaction of atmospheric dynamics and thermodynamic processes.
Distributed alpine glacier models usually require high-resolution climate forcing to adequately represent ablation and accumulation processes. An unresolved issue in distributed mass balance modelling is the simulation of snow cover dynamics with impacts not only on the accumulation but, through the strong effect on spatio-temporal albedo evolution, also on the ablation. With this in mind, I have focused my research activities on the snow cover dynamics on mountain glaciers and ice caps through a combination of measurements and high-resolution modelling of precipitation, wind fields and transport, snow density and albedo changes, and surface energy balance in a way that satisfies the multi-scale nature of the problem.
Patagonia is thought to be one of the wettest regions on Earth, although available regional precipitation estimates vary considerably. This uncertainty complicates understanding and quantifying the observed environmental changes, such as glacier recession, biodiversity decline in fjord ecosystems and enhanced net primary production. The observed dramatic volume loss of the Patagonian Icefields, for example, contradicts the reported positive surface mass balances. Here I use simple physical arguments to test the plausibility of the current precipitation estimates and its impact on the Patagonian Icefields.
Tropical cyclones represent an important component of intraseasonal atmospheric variabilityin the southwest Indian Ocean, and their landfall can be devastating to coastal communities. However,little is known about their impact on precipitation in the high‐elevation regions of East Africa. Here wecombine in situ measurements from the summit of Kilimanjaro and subkilometer atmospheric modeling ofthe region to investigate the impact of these storms during the 2006–2007 cyclone season, which wascharacterized by anomalously positive snow accumulation at the summit coinciding with cyclone activity.
In this study we used repeat bi-static synthetic aperture radar interferometry over the years 2000 to 2011/2015 and computed continent-wide, glacier-specific elevation and mass changes for 85% of the glacierized area of South America.
Here we detected the moisture sources of the Southern Patagonian Icefield with a Lagrangian moisture source method. The kinematic 18-day backward trajectory calculations use reanalysis data from the European Centre for Medium-Range Weather Forecasts (ERA-Interim) from January 1979 to January 2017.