overview of the 2005 montreal urban snow experiment (muse-2005)

Overview of the 2005Overview of the 2005Montreal Urban Snow Experiment Montreal Urban Snow Experiment (MUSE-2005)(MUSE-2005)

Mario BenjaminBruno HarveyFrédéric ChagnonGilles MorneauJocelyn MailhotStéphane BélairAude Lemonsu

CRTI Urban Canyon Project (0093RD) Annual Meeting – Dorval – August 24-25 2005.

Meteorological Service of Canada

Objectives

• Document the evolution of surface characteristics and energy budgets in a dense urban area during the winter-spring transition– Evolution of snow cover from ~100% to 0% in an urban

environment– Impact of snow on the surface energy and water budgets– Quantify anthropogenic fluxes in late winter and spring conditions

• Evaluate TEB in reproducing the surface characteristics and budgets in these conditions

• Gain expertise in urban measurements• Prepare for a wider effort to be submitted to CFCAS

Acknowledgements

• Prof Sue Grimmond, Indiana University• Prof Tim R. Oke, University of British Columbia• Prof James A. Voogt, University of Western

Ontario• Sarah M. Roberts

• This project was funded by CBRN Research and Technology Initiative as project # 02-0093RD

Selection of the site

• Selection of Montreal– Large city with significant accumulation

of snow (2.14 m/year)– Representative of Eastern Canada

winter climate– Availability of technical staff– Meso-scale surface meteorological

network– Wind profiler, RASS, McGill weather

radar

• Residential location seeked– Horizontal homogeneity, two and

three-storey attached buildings– Away from tall buildings and trees,

rivers, mountains, parks

• Easy and safe access to the site

N

1 km1 km

Selection of the site

Incoming and outgoing radiation

CNR1 radiometer Kipp & Zonen

Radiative surface temperatures

IR camera in heated case

Turbulent fluxes by eddy covariance 10Hz

3D sonic anemometer CSAT3

H2O/CO2 analyzer Li-Cor 7500

Fine wire thermocouple ASPTC

Air temperature and humidity in canyons

Radiative temperature of walls

Continuous measurements17 March to 14 April 2005

20 m tower

Intensive observation periods

• Clear skies and southwest winds• Four 26-hour IOPs (March 17-18, 22-23, 30-31, April 5-6)

• Measurements:– Hourly radiative surface temperatures using IR

thermometer– Albedo (5 daytime measurements)– Snow depth and density (5 daytime measurements)– Pictures to document snow cover, snow melt, wet

fraction

Radiative temperatures and roof snow fraction from IR camera

18 March 2005 19 March 2005

Sidewalk

Street

Roof

Infrared temperatures

-10

-8

-6

-4

-2

0

2

4

17/03

12:00

17/03

18:00

18/03

0:00

18/03

6:00

18/03

12:00

18/03

18:00

19/03

0:00

19/03

6:00

19/03

12:00

Day - Hour

Infr

ared

tem

pera

ture

(°C

)

Automated measurement (RayMI)

Back wall, first floor (manual)

Thermal camera - back wall

Frozen portion of the roof

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

1 8 15 22 29 36 43 50 57 64 71 78 85 92

Unfrozen pixelsFrozen pixels

19356 pixels used by images

17 March 22 March 30 March 5 April

Alle

yS

tree

t

Evolution of snow cover

Evolution of snow depth

0

5

10

15

20

25

30

35

40

45

17-0

3-05

18-0

3-05

19-0

3-05

20-0

3-05

21-0

3-05

22-0

3-05

23-0

3-05

24-0

3-05

Day - Hour

Snow

dep

th (

cm)

West sidewalk of Fabre street

Alley

Front lawn

Evolution of snow density

0

0,05

0,1

0,15

0,2

0,25

0,3

0,35

0,4

17-0

3-05

18-0

3-05

19-0

3-05

20-0

3-05

21-0

3-05

22-0

3-05

23-0

3-05

24-0

3-05

Day - Hour

Spe

cifi

c de

nsit

y

West sidewalk of Fabre street

Alley

Front lawn

Radiation measurements

Turbulent fluxes

Next steps

• Complete the quality control and post-processing of the data

• Format the data into an easy-to-use database• Estimate anthropogenic heat using energy

consumption data• Evaluation of TEB• Preparation of the second phase

– Rural, suburban and urban sites

The MUSE-2005 teamProject management:Michel JeanJocelyn MailhotMario Benjamin

Station installationBruno HarveyFrédéric chagnon

IOP manual measurementsStavros AntonopoulosNajat BenboutaMario BenjaminFrédéric ChagnonOlivier GagnonBruno HarveyAude LemonsuGilles MorneauRadenko Pavlovic

Weather briefingsJean MorissetteRobert Michaud

Evaluation of TEBStéphane BélairAude LemonsuClaude Pelletier