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 2012101100 case we have
switched to the new configuration using WRF version 3.4.1
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 3.1.1 YSU scheme in
our summer and winter 2-month tests
December Modification
• Beginning with the 2012122100 forecast, we
are now using the simplified ArakawaSchubert cumulus scheme instead of the old
Kain-Fritsch. Our studies show this to be a
superior scheme that eliminates the nonphysical precipitation bands of Kain-Fritsch.
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
00z
12z
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