WRF-DFI project meeting – 20060831

 

 

 

 

Hans, Min, Ju-Won, Wei Wang

Lilly room, 3:00-4:30pm, Thursday 31 August 2006

 

 1.Work review

 

1.1.  The KMA results

 

Ju-Won found something wrong in earlier verification which was misunderstood between local time and UTC. Now the best precipitation verification scores come from DDFI. Ju-Won also showed the conventional verification. The specific humidity was improved with DFI. Hans suggested drawing results for the cold start group and the cycle group separately.

 

1.2.  Switch on microphysics during backward integration

 

To solve the problem TDFI has longer spin-up time and lower precipitation rate than NODFI, Min made several tests:

l      No filtering the qvapor and hydrometeors. There is still a lot of noise.

l      Just filtering qv, dpsdt is still noisy.

l      During the backward integration, switch on the microphysics option but skip the calling of module-microphysics driver to make the hydrometeor arrays active.

A.    ThereŐre negative values in hydrometeor arrays from solve_em.

B.     It remove the moist-loops, no advection and diffusion (both explicit and implicit) for hydrometeors, the moisture arrays will be kept identical to these in wrfinput.

Using B for cycle tests, results show that the precipitation rate is still lower than NODFI.

HansŐ suggestions:

l      The negative values of hydrometeor arrays could be caused by the negative filtering coefficients. Make a test with the Lanczos filter.

l      Three options for moisture filtering: 1) Filtering qv and hydrometeors, 2) Save the qv and hydrometeors at t=0 during the forward integration procedure of filtering as the initial value of their filtered results; 3) Take qv and hydrometeors from the analysis (wrfinput).

 

2. Work plan for next week

 

Wei: Make a final version for the combined wrfvar and wrf+dfi.

 

Ju-won:   redraw to separate cold start ones and cycle ones; give Min the precipitation verification tool and a modified conventional verification program to calculate several each level; send Wei the latest code after check it out about diagnoses from MinŐs code.

 

Min:  Further tune dfi configuration; have a test using Lanczos filter; have tests by three option for moisture filtering (explained above).

 

3.AOB

 

Min return to BMB on next Monday(Sep. 4th 2006)

We will have the next project meeting on: Thursday 7 Sep, 2 pm, Lilly room.