An external view of the Met Office building at night.

Gemma Halloran (nee Bennitt)

Areas of expertise

  • Assimilation of GNSS ZTD observations into NWP models.
  • Assimilation of space-based Doppler Wind Lidar observations of wind into NWP models.

Current activities

Gemma is responsible for the development, maintenance and improvement of the observation processing and assimilation software for GNSS ZTD observations. She also monitors the observation quality. GNSS ZTD observations are received from across the world and are assimilated into the Met Office Numerical Weather Prediction models. The Met Office is a member of the EUMETNET EIG GNSS Water Vapour Programme, and Gemma is a member of the Expert Team on the use of GNSS water vapour measurements in NWP. We are also part of an EU COST Action on using GNSS for severe weather and climate (GNSS4SWEC) where Gemma is part of the Working Group on use of GNSS tropospheric products for high resolution NWP and severe weather forecasting, and leads the sub-working group on assimilation.

In addition to working on GNSS ZTD observations, Gemma will be developing the observation processing and assimilation software for wind observations from space-based Doppler Wind Lidars, namely ESA's Earth Explorer mission Aeolus.

Career background

Gemma joined the Met Office in 2007, starting work in her current role. Prior to joining Gemma gained an MSc in Applied Meteorology at Reading University with a Scholarship from the Royal Meteorological Society. She investigated the evolution of the 2006-2007 temperature anomalies in the equatorial Pacific for her dissertation. Before studying Meteorology, she received a Masters in Earth Sciences at Oxford University. There, her Masters research project investigated the potential of Ikaite to record past oceanic changes in the oxygen isotopic composition of water.