加藤研究室・大岡研究室・菊本研究室Kato Lab., Ooka Lab., and Kikumoto Lab.

Heat Island and Urban Climate

1/8

加藤研究室・大岡研究室・菊本研究室Kato Lab., Ooka Lab., and Kikumoto Lab.

The Concept of Urban Climate

2/8

（マイクロスケールα）

不安定領域

（都市循環流）

地衡風

ヒートアイランドによる上昇流

郊外 池・緑地

海

郊外 都心

高さ

[m

]

0

200

300

100

山

1km

10km（メソスケールγ）

100km（メソスケールβ）

日射

⑤（放射熱伝達（短波･長波））

大気放射

水蒸気 水蒸気

人工排熱 汚染物質

④（汚染物質輸送方程式）

①（運動量輸送方程式）

②（顕熱輸送方程式）

⑥（地中への熱伝導方程式） ⑦（地表面での放射･顕熱輸送･潜熱輸送などの熱収支式）

③（水蒸気輸送方程式）

クールアイランド

⑤(Radiant heat transfer (short wave / long wave)) ① (Momentum transport equations)

Upward flow by heat island

② (sensible heat transport equations)

Geothermal wind

Mountain

④ Pollutant transport equation

Cool island

Water vapor

PollutantArtificial

waste heat

Unstable region

(Urban circulation flow)③ (Water vapor transport equation)

Water vapor

Sea

atmospheric radiation

solar radiation

suburb City

center

Suburb

Pond/Green space

⑥ (Heat conduction equation to the ground) ⑦ (Heat balance equation such as radiation, sensible heat transport, latent heat transport on the ground surface)

(Microscale α)

(mesoscale γ)

(mesoscale β)

加藤研究室・大岡研究室・菊本研究室Kato Lab., Ooka Lab., and Kikumoto Lab.

Urban climate analysis using MM5

3/8

MM 5 (The Fifth-Generation NCAR / Penn State

Mesoscale Model)

Community model provided by NCAR (National Center

for Atmospheric Research). In the early 1970s, various

improvements were added based on the mesoscale

model developed by Anthes. Features of MM5 are as

follows.

(I) Introduction of non-hydrostatic pressure model

(Ii) Various physical options (cloud physics, rainfall,

turbulence model, etc.)

(Iii) Multi-stage nesting · 2-way nesting possible

(Iv) Create initial field from observation data etc.

(V) 4 dimensional assimilation possible

(Vi) Available on various platforms

Analysis region

Mesh split

X×Y

Horizontal mesh

width [km]

Domain1 50×60 9

Domain2 78×87 3

Domain3 99×120 1

Mesh split

加藤研究室・大岡研究室・菊本研究室Kato Lab., Ooka Lab., and Kikumoto Lab.

Comparison between static model and

non-hydrostatic model

4/8

HY model NH model

Air temperature (2 m above the ground) · Wind velocity vector

(10 m above the ground) Horizontal distribution

(Domain 3, August 5, 2005 12:00)

Velocity / Wind Velocity Vector Vertical Distribution

(Domain 1, August 5, 2005, 12:00)

Velocity / Wind Velocity Vector Vertical Distribution

(Domain 3, August 5, 2005 12:00)

Analysis date: August 4, 2005 9: 00 ~ 6 0:00

Analysis model: MM5 ver.2.12

Turbulence model: MRF PBL scheme

Radiation model: Radiation scheme by Dudhia

Initial condition: initial field created from NCEP final

analysis data

Dynamical model: Static dynamics model (Hydrostatic;

HY) and Non-hydrostatic model (NH)

HY model NH model

HY model NH model

加藤研究室・大岡研究室・菊本研究室Kato Lab., Ooka Lab., and Kikumoto Lab.

Improvement of MM5

Method of setting ground surface parameters and artificial exhaust heat

5/8

27

28

29

30

31

32

33

34

35

36

0 4 8 12 16 20 24

時刻

気温[℃

]

24

26

28

30

32

34

36

0 4 8 12 16 20 24

時刻

気温[℃

]

Analysis Case:

Case 1: ground surface parameter setting of the MM 5

standard, No artifical waste heat (base)

Case 2: Use land use data of national land numerical

information, No artificial exhaust heat (lu)

Case 3: ground surface parameter setting of the MM 5

standard, Integrated artificial waste heat (ah)

Case 4: Use land use data of national land numerical

information, Incorporate artificial exhaust heat (lu + ah)

Air temperature (2 m above the ground) · Wind velocity vector (10 m above the ground) Horizontal distribution

(Domain 3, 12: 00 August 6, 2005)

Case1 (base) Case2 (lu) Case3 (ah) Case1 (lu + ah)

Comparison with AMeDAS observations

(Domain 3, August 5, 2005)

Otemachi Saitama

Tem

pera

ture

Time Time

Tem

pera

ture

加藤研究室・大岡研究室・菊本研究室Kato Lab., Ooka Lab., and Kikumoto Lab.

Urban climate analysis model incorporating city canopy model

6/8

A mesoscale model using roughness length (case z 0)

Modeling nearby buildings, trees, etc. by roughness length

value

Since it is a model focusing on the flow of the upper layer of

the city canopy height, it is impossible to reduce the lattice

division in the vertical direction

Urban canopy model as surface boundary condition

Incorporated mesoscale model (case UC)

Evaluate the thermal environment of the height at which

humans are active

Wind velocity

短波↓ 短波↑ 長波↑ 長波↓ 潜熱 顕熱

伝導

（1）建物群による風速低減 （2）建物群による乱れの増大

（3）建物群による 短波放射の伝達効果

（4）建物群による 長波放射の伝達効果

（9）植生群による地表面 日射吸収量の減少

（5）建物表面からの 顕熱、潜熱放散

（6）植生群による風速低減 （7）植生群による乱れの増大 （8）植生群による放射の吸収

Wind velocity (1) Reduction of wind speed by building

(2) Increase of turbulence by building

(6) Reduction of wind speed by vegetation

(7) Increase of turbulence by vegetation

(8) Absorption of radiation by vegetation

(3) Transmission effect of short

wave radiation due to buildings

(4) Transmission effect of long wave

radiation due to buildings

(5) Sensible and latent heat from the

surface of the building

(9) Decrease of solar

radiation absorption on

ground surface due to

vegetation

Short wave ⇅ Long wave ⇅ Sensible and Latent ↑

加藤研究室・大岡研究室・菊本研究室Kato Lab., Ooka Lab., and Kikumoto Lab.

MM 5 analysis result incorporating urban canopy model

7/8

Air temp. / wind speed vector horizontal

distribution (12: 00 August 5, 2005)

a) case z0 a) case z0

Surface temperature distribution

(12: 00 August 5, 2005)

b) case UC b) case UC

0

500

1000

1500

2000

2500

3000

0 5 10

0

50

100

150

200

250

300

0 2 4

平均建物高さ

高さ

[m]

高さ

[m]

0

500

1000

1500

2000

2500

3000

300 304 308 312 316

0

50

100

150

200

250

300

304 306 308 310

高さ

[m]

高さ

[m]

平均建物高さ

0

50

100

150

200

250

300

304 309

case z0 case UC

Wind speed profile [m / sec]

(12: 00 August 5, 2005, Otemachi)

Temperature profile [K]

(12: 00 August 5, 2005, Otemachi)

He

igh

t

He

igh

t

He

igh

t

He

igh

t

Average building height

Average building height

加藤研究室・大岡研究室・菊本研究室Kato Lab., Ooka Lab., and Kikumoto Lab.

MM 5 incorporating urban canopy model

Comparison with AMeDAS observations

8/8

222426283032343638

0 4 8 12 16 20 24

case z0 case UC observation

-3

-2

-1

0

1

2

3

0 4 8 12 16 20 24

case z0 case UC

Temperature diurnal change

(August 5, 2005)

Temperature analysis error

(August 5, 2005)

22

24

26

28

30

32

34

36

38

0 4 8 12 16 20 24

[℃]

22

24

26

28

30

32

34

36

38

0 4 8 12 16 20 24

[℃]

-5

-4

-3

-2

-1

0

1

2

3

0 4 8 12 16 20 24

[℃]

-1

-0.5

0

0.5

1

1.5

2

0 4 8 12 16 20 24

[℃]

Comparison of ME and RMSEME RMSE

case z0 case UC case z0 case UC

Otemachi 0.034 0.309 0.557 0.653

Oume 0.165 -0.003 1.025 1.273

Nerima -0.167 -0.536 0.957 1.030

Hachioji 0.227 0.098 1.027 1.092

Fuchyu 0.220 -0.047 0.946 1.051

Shinkiba -0.223 -0.219 1.898 1.709

Haneda 0.136 0.160 1.192 1.024

Kuki 0.143 -0.309 1.632 1.675

Hatoyama 0.732 0.234 1.747 1.700

Saitama 0.111 -0.681 1.412 1.631

Koshigaya 0.194 -0.048 1.708 1.774

Tokorozawa -0.144 -0.270 1.472 1.159

Abiko 0.449 0.140 1.622 1.689

Funabashi 1.057 0.857 1.653 1.605

Sakura 0.919 0.687 2.039 1.993

Chiba -0.915 -0.441 2.467 1.931

Mohara 0.451 0.394 1.603 1.705

Kisarazu 0.360 0.542 1.541 1.643

Ushiku 0.727 0.314 2.357 2.364

Narita 2.102 1.487 2.442 2.123

Ebina 0.270 0.154 1.328 1.556

Yokohama -0.112 0.043 1.243 1.300

Tujido 0.922 0.830 1.275 1.177

Odawara 1.224 1.398 1.661 1.966

Tateno 1.781 1.216 2.269 2.074

Ryugasaki 0.942 0.545 2.063 1.923

Average 0.446 0.264 1.655 1.622

b)Tokorozawa

a) Otemachi

b)Tokorozawa

a) Otemachi