Consortium Meeting Feb 07, 2012

Our Audience, Hits: January 2013

Audience, Data Transfer stopped yandex yesterday

Inquiry from Canadians for Expansion Eric Meyer, Superintendent, Fire Weather, BC Wildfire Management Branch, Ministry of Forests and Range, PO Box 9502, Stn Prov Govt, Victoria, BC V8W 9C1 Want us to expand our 12km domain about 50% to reach the northern boundary of BC at 60 N latitude, and they would like us to expand the 4km domain about 50% to reach 55 N latitude. Need to double number of nodes, plus more disks for storage. Plus, backup costs Would give us more computer power for expansion of 1.3 km and a major computer refresh.

Upgrade Since Last Meeting 10/10/2012 Beginning with the case we have switched to the new configuration using WRF version with an unmodified YSU PBL scheme – using the newer implicit gravity-wave damping layer (damp_opt=3) – expanding the depth of the damping layer from 5 km to 7 km * – changing the vertical levels to more gradually increase in depth from the surface to a more nearly constant 1-km depth in the upper troposphere – raising our model top from 100 hPa to 50 hPa For the PBL scheme change has these features: – the newer YSU scheme gives similar wind speed and direction scores to our u-star modifications for the YSU scheme in our summer and winter 2-month tests

December Modification Beginning with the forecast, we are now using the simplified Arakawa- Schubert cumulus scheme instead of the old Kain-Fritsch. Our studies show this to be a superior scheme that eliminates the non- physical precipitation bands of Kain-Fritsch.studies

It was getting pretty silly…strange lines, generally in post-frontal, low stability situations

The origin? The Kain-Fritsch convective parameterization Comprehensive experimentation by Dave Ovens of all available convective schemes. Best choice: the same scheme used by NCEP for GFS model: SAS (Simplified Arakawa Schubert) scheme. Also improves our substantial underforecasting of summer convection over the mountains.

Old Kain-Fritsch

SAS

Old

New

Two Major Proposed Improvements Better radiation scheme-RRTMG Adding Land Surface model-RUC LSM

Radiation Dudhia simplified solar versus more sophisticated RRTMG: Air Force evaluation was the RRTMG is better:

RRTMG much more sophisticated

Some Results (all stations) Green (with RRTMG)

Land Surface Model (LSM) Land Surface Models provide much more sophisticated descriptions of surface properties and how they evolve. Generally provides much better dew point forecasts Snow pack can change in time. We had been using the NOAH LSM but found unacceptable cold biases over the interior. But things (and the model) have changed.

Testing LSM’s Old NOAH LSM (had cold bias) New NOAH MP (had stability issue) RUC LSM (tested comprehensively)

RUC LSM with RRTMG Radiation As expected dew point is much improved in summer.

Summer

Winter: Mixed, but RUC overall better

Winter Temp: Improvement

Winter Temp, Improvement

Summer Mixed Story

00z

12z

New Developments Yesterday, Dave figured out how to get around the snow problems with the old NOAH LSM. Yesterday, NCAR sent us a potential fix for the new NOAH LSM MP. Want to test these out. Recommend we go with the best of the bunch with new radiation and LSM.

Way Ahead After we have an optimized basic system, we should go back and add a modified version of our surface drag mods, which can help low wind speed situations (lessen mix out problem a bit). Then we revisit the shallow cold stable layer problem again.

The End