Dr Samantha Pullen
Samantha's work is aimed at assimilating information about the land surface, derived from satellites, into the Met Office's Numerical Weather Prediction system.
Areas of expertise
- Satellite imagery
- Land surface
- Data assimilation
Samantha's work aims to improve the representation of land surface characteristics in the initial conditions of the Unified Model. The land surface has an important impact on the atmosphere through fluxes of heat, momentum and moisture at the surface. An accurate representation of the land surface characteristics is therefore an important part of the NWP process.
Satellite imagers, such as SEVIRI and MODIS, are able to detect the land surface in the visible and infrared spectral ranges, allowing retrieval of properties such as snow cover, land cover, vegetation properties, and land surface temperature.
Samantha is working on improving the observational representation of snow and vegetation properties in JULES, the land surface module of the Unified Model. She has recently implemented a snow analysis for the northern hemisphere, which uses snow cover data from geostationary and polar-orbiting satellite imagers to update the snow amount in the Unified Model once a day. She is also working on implementing a new satellite-derived global dataset for leaf area index, with weekly updates to capture the effects of seasonal leaf fall and growth and crop cycles. Samantha is involved in the longer term strategy for land surface data assimilation, and the use of observations such as snow cover and leaf area index will continue to be developed as more sophisticated satellite products and assimilation options become available.
Samantha has been working in the Met Office's Satellite Applications group since she joined the Met Office in 1999. She has been working on land surface data assimilation for the last three years, previously working on assimilation of dynamical information from cloudy infrared satellite imagery, and assimilation of tropical convective rainfall rates derived from infrared imagery.
Before joining the Met Office, Samantha gained a PhD from Cambridge University, using model temperature errors to study middle latitude ozone depletion. As an undergraduate Samantha received a degree in Natural Sciences, also from Cambridge University.