UQAM/EC

Canadian Contribution to MAP D-PHASE

R. McTaggart-Cowan, M. Desgagne, J. Cote, S. Gravel, C. Girard, A. Erfani, J.

Milbrandt, C. JonesUniversity of Quebec at Montreal (UQAM) / Environment Canada,

Quebec, Canada

UQAM/EC

Outline

● Canadian motivation and support

● Description of the GEM modelling system

● Multiscale comparison of events in the MAP and Vancouver 2010 regions

– Dynamical and physical representation of heavy precipitation episodes in the model

● Opportunity for “proof of concept” and verification

UQAM/EC

Proposed Support

Canadian operational / on-demand support for MAP D-PHASE

UQAM/EC

Motivation for Involvement

● Regional experience from the original MAP project

– Identified problems by “stressing” the system

– Motivated improvements to model formulation

● Proof of concept for high resolution short-term forecasting in mountains – valuable for Vancouver Olympics 2010 project

– Venues are particularly sensitive to precip amount and species

UQAM/EC

Model Description

● Global Environmental Multiscale (GEM) model has been developed extensively since the MC2 was used in MAP

● GEM runs in global (uniform/variable reso) + LAM configuration – unified model structure

● Non-hydrostatic primitive equations solved using an Implicit SL scheme

Operational G

EM

R

egional stretched C

onfiguration

UQAM/EC

Model Description

● Self-nesting allows for a consistent use of physical parameterizations:

– Kong and Yau microphysics (2 liq, 2 ice) – upgrade to Milbrandt and Yau is possible

– TKE boundary layer closure

– Kain-Fritsch convection (10 km MAP-Regional domain only)

● This allows nesting of hydrometeor species – important to reduce spin-up

UQAM/EC

Predictability: Large Scale

● Synoptic scale patterns modulate the internal structure of the systems – they must be well-represented

MA

P IO

P-2 C

yclone enhanced IR

image 1200

UT

C 20 S

eptember 1999

Van

couv

er s

now

(35

cm

Cyp

rus)

enh

ance

d IR

imag

e 06

00 U

TC

8 M

arch

200

6

UQAM/EC

Predictability: Large Scale

● Despite satellite DA, useful predictability can be <6h on West Coast

● Ensemble techniques may be an approachObservation increm

ent from

AM

SU

-A brightness

temperatures 14 F

eb 2006

Obs

erva

tion

incr

emen

t of

radi

oson

de te

mpe

ratu

res

for

16 J

une

2006

x

UQAM/EC

Regional Modelling

● Use of an intermediate domain (10km) will promote development of mesoscale signal and permit hydrometeor nesting

UQAM/EC

High Resolution Modelling

● During MAP, MC2 ran with smoothed (approximately x5) orography – GEM will run with full resolution field

UQAM/EC

High Resolution Modelling

● MAP revealed problems with the MC2

– New vertical coordinate (Schar) developed

– Numerical inconsistency eliminated

● Reduction of GEM waves is a priority

GEM with standard background GEM with modified background

Vertical motion fields from the GEM for a cosine idealized mountain case (C~.5)

Model Dynamics

UQAM/EC

High Resolution Modelling● Advanced microphysics scheme is being

developed for GEM – 3 moment bulk with 2 liquid, 4 ice phases (Milbrandt and Yau)

10020 40 60 800

101

100

10-1

10-2

Multimoment bulk estimate of DSD

N(D

)

Diameter

Observed1 Moment Bulk3 Moment Bulk

● Accurate DSD shape prediction important for fall speed estim-ates and conversion rate calculations

Model Microphysics

UQAM/EC

High Resolution Modelling

Model Microphysics

CLOUD(CLW)

RAIN

ICE / SNOW

GRAUPEL / HAIL

Kon

g a

nd

Yau

1 M

om

en

t M

icro

ph

ysi

cs

1 Moment mass

Unobserved heavy precipon the lee side

Almost no graupel formed(low riming rates)

Pockets of liquid water are known to form in persistent terrain-induced updrafts and provide ideal regions for rapid riming growth of snow

UQAM/EC

RAIN

ICE(pristine crystal)

SNOW(large crystals / aggregates)

GRAUPEL HAIL(ice pellets)

CLOUD(CLW)

High Resolution Modelling

Model Microphysics

Milb

ran

dt

an

d Y

au

3 M

om

en

t M

icro

ph

ysi

cs

Windward and leeward precip in line with obs

Large graupel growthrates by riming

3 Moment mass

UQAM/EC

High Resolution Modelling● Multimoment microphysics scheme reduces

known accumulation and lee-side heavy precipitation problems with single moment schemes (e.g. IMPROVE case)

● High resolution in steep terrain will challenge the numerics of GEM

● High resolution verification data is hard to obtain but invaluable in scheme evaluation and further development

UQAM/EC

Verification and Development● MAP and MAP D-PHASE produce unique

verification datasets

● D-PHASE will also be useful for model intercomparison at very high resolution

– Quasi-operational status will yield statistically significant results on un-tuned cases

– May be able to address the question of how much resolution is really needed? (> 3km)

UQAM/EC

Conclusions● Addition of

development cycle helps us to realize the full potential of MAP D-PHASE

Dev

elop

men

t Cyc

le

adde

d to

Can

adia

n O

pera

tion

al S

uppo

rt

● Coupled or offline hydrology model development will be integral for Vancouver 2010 forecasting