The ECMWF/EuroTRMM Workshop on the Assimilation of Clouds and Precipitation was held from 6 to 9 November 2000.
The first four dimensional variational (4D-Var) data assimilation system was put in operations at ECMWF on November, 25 1997. Two days later (27-11-1997), the Tropical Rainfall Measuring Mission (TRMM) satellite was successfully launched from the Tanegashima Space Center (Japan). These two important events of the atmospheric science have opened up a new era for satellite measurements (TRMM being the first mission with space borne rain radar) and for their use in numerical weather prediction (4D-Var being more efficient that previous analysis systems for the assimilation of satellite data).
The workshop was jointly organized by ECMWF and the coordinators of EuroTRMM. The proceedings contain a description of the key results obtained by the various European laboratories involved in this 3-year collaboration. They also include recent developments performed outside ECMWF on the assimilation of rainfall rates. Even though less mature that the assimilation of precipitation, the interest for cloud assimilation is growing in the scientific community by the advent of new satellite explorer missions with active instruments (radar/lidar). Several presentations were devoted to explore this area of research. The task of the four working groups was to identify the observational data sets that could be used for data assimilation, the necessary developments in terms of physical parametrization scheme and retrieval methods, and the improvements required to data assimilation systems for a better usage of cloud and precipitation data.
Validation of the TRMM PR rain retrieval algorithm from airborne and ground-based radar data
PR adjusted TMI estimation of rainfall
Requirements for the assimilation of cloud radiances
Variational assimilation of precipitation data and gravity wave adjustment
Validation of cloud fraction and overlap using radar and lidar observations
R J Hogan
Lessons from TRMM and plans for GPM
A Y Hou
The evaluation of cloud parametrization in GCMs - are we doing the best we can?
Linearized physics for the assimilation of cloud properties
Sea surface scattering under rainy conditions
4D-Var assimilation of TMI rainfall rates
Assimilation of precipitation in the Met Office mesoscale model
Cloud-model based Bayesian techniques for precipitation profile retrieval from TRMM microwave sensors
Validation of a convection scheme using TRMM data
Validation of cloudiness in gcms using Meteosat observations
Precipitation analysis based on gauge measurements
Estimation of surface latent heat flux from TRMM
Cloud assimilation in the era of CLOUDSAT
Rain characteristics in tropical regions: measurements from radars and ground-based instruments
Field experiments in support of EuroTRMM
Modelling microwave scattering in the melting layer
C J Walden