D32   Impact of surface humidity observations on GPS assimilation.

Responsible partner
Due date

This is part of work-package 5000, the purpose of which is to enable assimilation of surface humidity observations and carry out an impact assessment.  The purpose of sub wp 5200 is to study the impact.

-         To test the impact of using humidity information from surface stations in combination with ground-based GPS information

Methodology/Work Description:

The ground-based GPS measurements in principle only provide information on the vertically integrated water vapour in the atmosphere above the GPS stations. It was shown by Kuo et al. (1996) in an observing system simulation study that more information on the vertical distribution of the moisture could be retrieved by adding humidity observations from surface stations. This possibility to improve the utilisation of ground-based GPS measurements will be investigated by running a 3D-Var data assimilation and forecast experiment over one month with and without 2-meter relative humidity observations.

Deliverable.  The results of the impact studies with surface humidity are included in the reports on the other impact studies carried out at INM. They are all described in the reports INM assimilation results (text) and Figures to INM assimilation results. For further information contact Jana Sanchez-Arriola, Beatriz Navascues or J.A. Garcia-Moya at INM. Notice that also the previous deliverable, D31 contains impact results regarding use of surface humidity observations.