BMB-UCAR WRF 3D-Var project

Summary for 12 August – 25 August 2006

Reporting time (for this report): 28 August 2006

 

 

Task 5. Meteorological performance

5.1. BE

 

Using the updated wrfvar version with BE interpolation code provided by Yongrun, 

Shuiyong interpolated the BE from 27km to 9km to generate the nested BE.  With the new 9km BE, Shuiyong conducted an experiment to check the response of temperature and wind to a single temperature observation and three experiments to assimilate TEMP/SYNOP, AWS and GPSPW respectively.

 

5.2. WRFDFI

 

Yongrun adopted the wrf_io.F90 from WRFV2.2 to wrfvar2.1 to make wrfvar2.1 can work with both WRFV2.1 and WRFV2.2 for cold-start and cycling runs. Thus, the problem that WRFV2.2 canŐt run in cycling mode has been resolved. The TDFI/NODFI cycling tests has been performed for Beijing model configurations. From the filtering results and verification scores, DFI parameters need further tuning.

 

Progress should be reported next time. (Min)

 

5.3. Comparison

 

No report in any form from Zaiwen. He explained that as the codes of verification on pressure levels havenŐt been developed yet, he couldnŐt perform the comparison between MM5 and WRF with different standards. This task seems to depend on the working status of task6.1.

 

Task 6. Monitoring of pre-operational runs and case studies

 

6.1. Verification

 

Verification package from Zhiquan Liu is developed using MATLAB. So Min and Jiqin need more time to work on this task.

 

6.2. OSE

 

Jiqin provided some results of GPS data assimilation experiments. From YongrunŐs comments, the bias error (O-B) for GPSPW is too large, which indicates that BMB GPSPW data processing is still having problems. If having this large bias error, we should do the bias correction prior to assimilations, otherwise the results may not make sense because violation of the assumption of VAR. Yongrun suggested that in stead of performing assimilation and forecast experiments, we should do some statistics calculation on GPSPW (O-B) for a period (multiple cases) first.

 

6.3. Cycling

 

A cycling script system is ready and the bug of the incompatibility between wrfvar and wrf model has been fixed by Yongrun. Cycling experiments have been performed.

 

However, the work was planned to start in October. No report is required.

 

6.4. Tuning

 

No report about this task this week.

 

The tuning work was planned to start next year. No report is required from Zuofang.

 

6.5. MM5DFI

 

The work was planned to start next year. No report is required.

 

Next report time: 8 September 2006!!