Project aims

The major aims of DAPAGLOCO are:

first, to improve the DAPACLIP precipitation data set, developed within MiKlip-I, in terms of data density and temporal coverage, and second, to prepare for the operationalisation and regular update of the comprehensive high-quality global daily precipitation dataset allowing the analysis of extremes.

Furthermore, probabilistic forecasts of precipitation fields are evaluated in cooperation with other MiKlip projects. The results from this evaluation have the potential to improve forecasts through better bias corrections and are valuable for further development of the forecasting model.

Project Structure and tasks

A global daily precipitation analysis, covering the time period from 1988 to 2015, will be delivered by the MiKlip-DAPAGLOCO project. It builds on the precursor version from MiKlip-DAPACLIP and is based on two major components consisting of:

1. Station-based rain gauge data over land from the Global Precipitation Climatology Centre (GPCC); and

2. Precipitation data over ocean retrieved from satellite-based microwave imagers, benefitting from DAPACLIP and HOAPS („Hamburg Ocean Atmosphere Parameters and fluxes from Satellite data“). The data set is extended to 2015 by using inter-calibrated data from various microwave imagers.

The DAPAGLOCO data set includes uncertainty estimates of precipitation rates and information on station density (over land) and number of satellite overpasses (over ocean) for the assessment of data reliability on a grid-box scale.

DAPAGLOCO is structured into tasks:

- Further improvement of the data set and of the satellite retrieval scheme

- Further investigation of the merging process of land and ocean data for an optimal combination of both components

- Validation of the combined product against other regional products and/or reanalysis data

- Comparison of the combined data set to other precipitation products and reanalysis data available from CES and identification of areas of high variability to support the interpretation of results from forecast evaluation

- Applying the common approach for the evaluation of decadal forecast skill for optimal comparison with results from other work packages

- Initial operationalisation of the processing chain

- Plugin tool for the MiKlip evaluation system using the DAPAGLOCO data set

- User support

Deliverables

A global precipitation climate product with a high temporal stability and resolution for the evaluation of the MiKlip forecasting system.

Progress so far

A version of the merged precipitation data set was published and DOI-referenced. Furthermore, a publication about the data set and a precipitation climatology based on ETCCDI-indices was published in MDPI Climate. Quality-controlled data from additional stations were included into GPCC, justifying the release of a new version of the station-based daily product. Also, data from various satellite instruments have been pre-processed and the combined product of satellite-based and station-based precipitation estimates is currently in a state of finalisation, after which it will be validated and made available to the community.