气候科学尺度不匹配：全球模拟、局地尺度土地利用及高精度遥感观测BRIDGE THE SCALE GAP IN CLIMATE SCIENCE: GLOBAL CLIMATE MODELING, LOCAL LAND USE AND FINE-RESOLUTION REMOTE SENSING

李旭辉XUHUI LEE

耶鲁大学-南京信息工程大学大气环境中心

Collaborators

Yale University Natalie Schultz

Ron Smith

Lei Zhao 赵磊 (now at Princeton)

National Center for Atmospheric Research David Lawrence

Peter Lawrence

Keith Oleson

Nanjing University of Information, Science and Technology Chang Cao 曹畅 Shoudong Liu 刘寿东 Wei Xiao 肖薇 Mi Zhang 张弥

Collaborators

Yale University Natalie Schultz

Ron Smith

Lei Zhao 赵磊 (now at Princeton)

National Center for Atmospheric Research David Lawrence

Peter Lawrence

Keith Oleson

Nanjing University of Information, Science and Technology Chang Cao 曹畅 Shoudong Liu 刘寿东 Wei Xiao 肖薇 Mi Zhang 张弥

Components of an earth-system model

Land Atmosphere

Sea ice Ocean

Coupler

Fossil combustion

Land use change (deforestation, urbanization)

Agricultural intensification

Human activities

Earth-systemmodel

Model grid size versus local land use

100 km10

0 km

Model grid size versus local land use

5 km

Yale Myers Forest

Model grid size versus local land use

Yale Myers Forest

Model grid size versus local land use

10 km

City of New Haven

Model grid size versus local land use

City of New Haven

A-train satellite constellation

Source: NASA

MODIS satellite land products

Land cover classificationLand surface temperature(October 6, 2016)

1 km

1 km

Sentinel 2 satellite pair

Sioux Falls, SD, October 1, 2015

10 m

10 m

Remote sensing with drones

Goshen FarmLitchfield County Connecticut

5 cm

5cm

Oleson et al (2013) NCAR’s Technical Note

Modeling land grids as tiles or land units

Blending heightTaK↓ L↓

Ts

Ta

Urban heat island Ts

Vegetated Urban land

Blending height in a model grid

Blending heightTaK↓ L↓

Ts

Ta

Deforestation signal Ts

Forest Open land

Blending height in a model grid

Vegetation in a model grid

Savanna

Mosaic

Deforestation effect using savanna-type land model

Schultz, Lee, Lawrence et al. (2016) J Geophysical Research – Atmospheres: doi 10.1002/2016JD025094

Deforestation effect using mosaic-type land model

Schultz, Lee, Lawrence et al. (2016) J Geophysical Research – Atmospheres: doi 10.1002/2016JD025094

Latitude (oN)25 35 45 55 65

Annu

al m

ean

diffe

renc

e

T (K

)

-2

-1

0

1 y = -0.070(±0.020) x + 2.6(±0.9)n = 37, R2 = 0.30, p < 0.005a

-10 20 50-2

0

Deforestation effect on surface air temperature (open land minus forest land)

Lee, Goulden, Hollinger et al. (2011) Nature 497: 384-387

0.070 0.020 2.6 0.9

N/S America

Asia

Zhang 张弥, Lee, Yu, et al. (2014) Environ Res Letters 9: 034002

Deforestation effect on surface air temperature (open land minus forest land)

Deforestation effect on land surface temperature

MODIS satellite observation

Mosaic-type land model

Savanna-type land model

Temperature difference (K)

Savanna-type land model

Mosaic-type land model

MODIS observation

Latit

ude

Night lights viewed from outer space

Global• Urban land fraction = 2.2%• Urban population = 51%• Urban C contribution = ~80%

USA• Urban land fraction = 2.6%• Urban population = 79%

Arizona / Sun Corridor• Urban land fraction = 0.34%• Urban population = ~88% of 6.6 million in 2013• Projected urban population = ~95% of ~19 million in 2050

Heat stress is perhaps the biggest climate threat to humans

Image source: Driscoll

Maximumskin temperature

35o

Cold environment

Hot environment

A typical urban heat island

Source: Oke

Urban heat island and land use in New Haven

Land use classesSurface temperatureJuly 4, 2010

Major causes of the urban heat island phenomenon

Source: Oke

Urban surface energy balance

SAHs QLEHQTLK 4)1(

Heat storage

Evaporation

Convection

Anthropogenic heat

Albedo

Theory on attribution of the urban heat island

AH

s

AHsn

AHsn

n

Qf

Qf

fQQRf

fQQRf

Rf

T

1

1

)()1(

)()1(

1

0

0

2*

20

1*

20

*0

Radiation

Convection

Evaporation

Storage

Anthropogenic heat

Radiative forcing versus energy redistribution

Solar Longwave

TOA

Evaporation

Atmospheric boundary layer

Convection

• at the local scale

Climate sensitivity

Intrinsic sensitivity

Apparent sensitivity

• 0.3 K per W m-2 at the global scale

• 0.2 K per W m-2 at the local scale

• and

• ~0.8 K per W m-2 at the global scale

AHsn

n

fQQR

fQQRf

Rf

T

)(

)()1(

1

*0

1*

20

*0

+ …

CLM‐modeled UHI versus UHI calculated from the surface 

energy balance

AH

s

AHsn

AHsn

n

Qf

Qf

fQQRf

fQQRf

Rf

T

1

1

)()1(

)()1(

1

0

0

2*

20

1*

20

*0

Daytime

Nighttime

Sum of components – another formulation

Daytime

Nighttime

Albedo

day

day day

night night

night

Zhao 赵磊, Lee, Smith, Oleson (2014) Nature: 511: 216-219.

Annual UHIAttribution

Annual UHI Attribution(China)

Cao 曹畅, Lee, Liu, et al (2016) Nature Communications: doi: 10.1038/ncomms12509

Daytime Nighttime

Dry climate

Humid climate

Semi-humid climate

White roof, green roof, solar roof, and street trees

Sources: www.ens‐newswire.com/ens/sep2008/2008‐09‐23‐01.html; http://aasid.parsons.edu/ 

White roof in California Green roof, Chicago City Hall

Street trees, NanjingSolar roof, Yale University

Re-engineering the urban landscape

Image data source: Sensefly.com; Animation credit: Chang Cao 曹畅