CHEMICAL FORECASTS WITH THE ECHAM MODEL

Martin Schultz (martin.schultz@dkrz.de, ph: +49 40 41173-308)
Hans-Stefan Bauer (stefan.bauer@dkrz.de, ph:            -404)

We will provide daily results from 4 day forecast simulations with the ECHAM GCM nudged to ECMWF forecast fields in 6-hourly time resolution.  These will be ready for download in the field (Hongkong and Yakota) before 8 am local time and then be valid as 3 day forecasts. The model simulations will be carried out in T106 resolution (~1.1x1.1 deg) and include Radon-222, several CO tracers tagged by emission region and type (anthropogenic or biomass burning) and several climate state variables (especially cloud cover, precipitation).

The data shall be transferred into the field electronically via ftp in two formats:

(1) a series of compressed postscript files with standardized plots zoomed in over the North Pacific and on at least 4 standard levels (850, 700, 500, 300 hPa)

(2) a set of 3-dimensional fields in vis5d format which can be readily animated on a laptop computer which we will bring into the field but could also be converted for use with the CAVE system.

We plan to transmit plots for at least 6 time steps (0h, +12h, +24h, +36h, +48h, +60h relative to local noon in the field) which means about 150MB per day. The 3-dimensional data sets will also be on the order of 150MB per day if we transfer 6 "codes" (variables) for the greater Pacific region with 6h time intervals. It will be easy to adjust the number of fields and amount of data depending on their usefulness and the available connection. We will be able to adjust the output almost on a daily notice but we would like to standardize our products early in the field phase.

We will bring laptop computers to retrieve and process the data, but we would like access to a color printer and a beamer for producing plots and animations. Postprocessing of data in the field should not take longer than 1 hour.

Martin Schultz will be in Hongkong and Hans-Stefan Bauer will be in Yakota to handle our data and prepare presentations for the flight planning sessions.

After the TRACE-P experiment, we will rerun the model using the ECMWF analysis fields and compare the results with the forecasted fields.