Mesoscale Urban Modeling: Mesoscale Urban Modeling: Inclusion of Inclusion of Anthropogenic HeatingAnthropogenic Heating

Najat Benbouta Environmental Emergency Response Division, CMC

Main factors of UHI effect:

■ Alteration of land usage■ Geometric urban configuration■ Ground covering materials

■ Increase of anthropogenic heat Traffic Vehicles (Cars, Trucks, Trains …) … ~ 60% (typical US city) Building ( Residential, Commercial, Industrial) …. ~ 40% (typical US city) Metabolism Heat …. ~ 2%

Urban Heat Island (UHI):

In order to quantify the impact of these factors we must understand the underlying Surface Energy Balance in urban areas TEB

QH topQE top

QH trafficQE traffic

QH industryQE industryQH roof

QE roof

Water Snow

Ti bld

Ua , Ta , qa

Troof1Troof2Troof3

Twall1Twall2Twall3

Troad1Troad2Troad3

SnowWater

QH roadQE road

Tcanyonqcanyon

QH wallQE wall

Rroof

Rwall

Rroof Snow

Rroad Rroad Snow

Rtop

Atmospheric level

Input dataPrognostic variablesDiagnostic variables

Aude Lemonsu, CRTI-2005 Meeting

■ Building-level energy

■ Detailed data required Expensive

■ Specific analyses Not replicated across a range of cities.

Evaluation of Anthropogenic HeatingBottom-up Approach (T. Ichinose, Japan, 1996)

Area energy consumption for each category on business or land use in Tokyo in 1989. Annual ValuesComplex to generate

and to maintain

Anthropogenic Heating:Top-Down Approach, Vehicle Traffic Profile

0.00%

1.00%

2.00%

3.00%

4.00%

5.00%

6.00%

7.00%

8.00%

9.00%

0 5 10 15 20 25

Hour

Tra

ffic

Fra

ctio

n

Atlanta Austin

Chicago Los Angeles

OH State PA State

San Francisco National

Hourly fractional traffic profiles – fv(t) for various US cities and states. Bold line is national profile from Hallenbeck et al., 1997).

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Evaluation Of Anthropogenic HeatingTop-down approach (D. J. Sailor, USA, 2004)

MetabolismQ

BuildingQ

VehicleQ

FQ

DVDEtFtQ VVpopVehicle

ρpop(t) Population density [person/km2] FV(t) Non-dimensional vehicle traffic profile EV Vehicle energy used per kilometer [Wkm-1] DVD Distance traveled per person [km] Analysis at the city scale

Hourly non-dimensional profile functions per capita

Spatial refinement through the hourly density of population profile

Daily total energy released by 1 vehicle

Anthropogenic Heating:Top-Down Approach, Aggregated Profiles

Chicago

01020304050607080

0 8 16 24

Qf

(W m

-2)

SummerWinter

Los Angeles

01020304050607080

0 8 16 24

Local Hour

Qf

(W m

-2)

Philadelphia

01020304050607080

0 8 16 24

Local Hour

Qf

(W m

-2)

San Francisco

01020304050607080

0 8 16 24

Qf

(W m

-2)

Aggregated Qf profiles (at city-scale)

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Plan:• Search for data sources• Analysis of the data• Definition of the anthropogenic profiles per sector• Building of the anthropogenic heating database

Anthropogenic Heating: Top down approachProduction of a database for Canada & USA

Develop first prototype for Montreal Validation of the approach with detailed high resolution dataGeneralize to other cities of North America

Questions ?

Diurnal variability of demand for space cooling in summer, space heating in winter, hot water supply in winter and the diurnal variability of area energy consumption in the manufacturing and transportation. Ichinose, 1996

Anthropogenic Heating:Top-Down Approach, Electricity Profile

SUMMER

0.030

0.035

0.040

0.045

0.050

0.055

0 4 8 12 16 20 24

WINTER

0.030

0.035

0.040

0.045

0.050

0.055

0 4 8 12 16 20 24

NWPPC PJM ISO NY ISONE ISO Entergy CA ISOAverage

Representative hourly fractional electricity profiles – fe(t)

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Anthropogenic Heating:Top-Down Approach, Heating Fuel Profile

0.00

0.01

0.02

0.03

0.04

0.05

0 4 8 12 16 20 24

Local Time

f hf

-1.0

1.0

3.0

5.0

7.0

9.0

Tem

p (

C))

Representative hourly heating fuel profiles

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Results for the 6 US Cities Studied:

■ Heating from vehicle was the dominant in the summer for every city, 47% - 62% of the total.

■ Relative importance of heating fuels increases in the winter in the cold cities, 57% of the total for Chicago.

■ Metabolic heat is the least important component 2-3% of the total heating.

Urban Heat Island:Impact Of Anthropogenic Heating?