NSO funds earth observation projects from Susan Steele Dunne and Stef Lhermitte

A new perspective on global vegetation water dynamics from radar satellite data 

Improved understanding of how vegetation regulates land-atmosphere exchanges of water, carbon and energy will benefit hydrology, water management and climate science. Susan Steele Dunne obtained funding for her proposal ‘A new perspective on global vegetation water dynamics from radar satellite data’, which will be an essential step towards a global climate data record of vegetation water dynamics. It will give scientists new insight into the role of vegetation in land atmosphere interactions, and the coupled water, energy and carbon cycles. It will also contribute to an improved understanding of microwave interactions with vegetation, which will contribute to improved soil moisture products as well as improved and new vegetation products. This will benefit a wide range of applications including agriculture, hydrology, water management, numerical weather prediction, forest fire monitoring, and ecosystem monitoring each of which is of direct societal relevance. Susan’s latest research demonstrated that the seasonal, inter-annual and diurnal variations in the new “dynamic vegetation parameters” derived from ASCAT (long term meteorological satellite data) reflect vegetation phenology and moisture content variations in soil and vegetation. In this study the ASCAT dynamic vegetation parameters will be used to directly monitor vegetation water processes and to detect changes in vegetation water processes in response to drought.

Remote sensing of damage feedbacks and ice shelf instability in Antarctica

Ice shelves, which are the floating parts surrounding 75% of Antarctica’s coastline, play an important role in Antarctica’s contribution to sea level rise. Ice shelves act as border control: by providing resistance to the ice, they prevent the land ice to enter the ocean and as such slow down sea level rise. When these ice shelves are weakened, for example due to surface/ocean melt or due to weakened shear zones as a result of damage, they become potentially unstable. This can result in ice shelf collapse, causing accelerated glacier flow and increasing sea level contributions. Stef Lhermitte obtained NSO funding for his proposal ‘Remote sensing of damage feedbacks and ice shelf instability in Antarctica’ which focuses on assessing how much and how fast Antarctica’s ice shelves are weakened. Until now, this remains a major uncertainty in projections of sea level rise as many of the processes that control ice shelf instability are not well understood or quantified. For example, the weakening of ice shelves due to damage in the shear zones is considered key for the collapse of Larsen-B ice shelf and the retreat of Pine Island Glacier and Thwaites Glacier, whereas at the same time it has been identified as one of the least understood processes in marine ice sheet dynamics. The recent availability of frequent, high resolution, multi-source satellite imagery across all Antarctic ice shelves and the advent of big data and machine learning approaches offer now the opportunity to develop approaches to assess and understand the impact of these damage (changes) on ice shelf instability. The objective of this project is to use remote sensing and big data approaches i) to develop damage indicators across all Antarctic ice shelves and ii) to assess the potential impact of these damage areas on future ice shelf stability. This will allow evaluating the role of damage areas and their impact on ice shelf stability on future sea level rise under different scenarios.