cost-728 workshop on model urbanization strategy ukmo, exeter, uk, 3-4 may 2007 university of athens...
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COST-728 Workshop on‘Model urbanization strategy’UKMO, Exeter, UK, 3-4 May 2007
UNIVERSITY OF ATHENS FACULTY OF PHYSICSDEP. OF APPLIED PHYSICSLAB. OF METEOROLOGY
Sensitivity tests in the Sensitivity tests in the ‘‘dynamicaldynamical’’ and and ‘‘thermalthermal’’ part of the part of the MRF-urban PBLMRF-urban PBL scheme scheme
in the MM5 model in the MM5 model
Aggeliki Dandou, Maria Tombrou
COST-728 Workshop on‘Model urbanization strategy’UKMO, Exeter, UK, 3-4 May 2007
Meteorological Model
MM5 (Version 3-6)
The Penn State/NCAR Mesoscale Model MM5 (Grell et al., 1994) is a terrain following numerical weather prediction model, with a multiple-nest capability, nonhydrostatic dynamics and a four-dimensional data assimilation capability.
• ‘simple ice’ Hsie et al. (1984), for the moisture parameterization
• ‘cloud-radiation scheme’ Dudhia (1989), for the radiation parameterization
• ‘Grell’ (1993), for the clouds parameterization
• ‘Five-Layer Soil model’ (Dudhia, 1996), for the soil parameterization
Parameterization schemes considered:
1
COST-728 Workshop on‘Model urbanization strategy’UKMO, Exeter, UK, 3-4 May 2007
Meteorological Model MM5 (Version 3-6)
MRF (Hong and Pan, 1996): high resolution non-local scheme based on Troen and Mahrt (1986) representation of counter gradient term and K profile in the well mixed PBL MRF-urban (Dandou et al., 2005): a modified version of MRF whereby urban features were introduced both in the thermal part and the dynamical part:
• Anthropogenic heat: as a temporal and spatial function of the diurnal variation of the anthropogenic emissions
• Heat storage: the OHM scheme (Grimmond et al., 1991)
PBL parameterization schemes:
• Heat and momentum fluxes (under unstable conditions): according to Akylas et al. (2003)
• Diffusion coefficients (under stable conditions): according to King et al. (2001)
• Updated field for the roughness length: based on literature values in combination with satellite detailed information on land use (spatial resolution 30 m)
2
MRF-not urban: a modified version of MRF, whereby the city of Athens is replaced by dry cropland and pasture surface, as the surrounding area
COST-728 Workshop on‘Model urbanization strategy’UKMO, Exeter, UK, 3-4 May 2007
Area of application
Meteorological data ECMWF (0.5o x 0.5o) every 6 hours
Sea Surface Temperature SST (1o x1o) every 6 hours
USGS data (25 categories) (30’’ x 30’’) for topography and land use
Two-way nesting
Input dataInput data
3
Ground stations
• National Observatory of Athens (NOA), an urban station (4 km inland from the shore), located in a park, on top of a hill (107 m asl), with urban characteristics 85% and z0=0.8 m
• Marousi, a suburban station (13 km inland from the shore), inside a grove surrounded by buildings of different heights, with urban characteristics 52% and z0=0.5 m
• Peiraias, an urban station at the harbor, with urban characteristics 100% and z0=1 m
1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 1 0 0 1 1 0 1 2 0 1 3 0
1 0
2 0
3 0
4 0
5 0
6 0
7 0
8 0
9 0
1 0 0
1 1 0
1 2 0
1 3 0
(x 6
km)
5 10 15 20 25 30 35 40 45 50 55
(x 2 k m )
5
10
15
20
25
30
35
40
45
(x 2
km) (x 6 k m )
M a ro u si
P e ira ia sN O A
COST-728 Workshop on‘Model urbanization strategy’UKMO, Exeter, UK, 3-4 May 2007
4
Available measurementsAvailable measurements
14 September 1994 (MEDiterranean CAmpaign of PHOtochemical Evolution
MEDCAPHOT-TRACE experiment, Ziomas, 1998)
• Air temperatureAir temperature
• Sensible heat fluxSensible heat flux ( (sonic anemometer)sonic anemometer)• Friction velocity (sonic anemometer)Friction velocity (sonic anemometer)
• Wind velocityWind velocity
NOA, Marousi
NOA, Marousi, Peiraias
• Landsat TM satellite imageLandsat TM satellite image (acquisition date(acquisition date: 13 : 13 JouneJoune 1993)1993)
COST-728 Workshop on‘Model urbanization strategy’UKMO, Exeter, UK, 3-4 May 2007
5
ResultsResults
Surface fluxesSurface fluxes
Air TemperatureAir Temperature
Diffusion coefficientsDiffusion coefficients
PBL heightPBL height
Surface fluxesSurface fluxes
COST-728 Workshop on‘Model urbanization strategy’UKMO, Exeter, UK, 3-4 May 2007
6
Diurnal variation of surface fluxes (MRF-urban scheme)
Peiraias
-100
0
100
200
300
400
500
600
700
0 2 4 6 8 10 12 14 16 18 20 22 24
time (h) LST
W/m
2
Q*
QH
QE
QF
ΔQs
Marousi
-100
0
100
200
300
400
500
600
700
0 2 4 6 8 10 12 14 16 18 20 22 24
time (h) LST
W/m
2
Q*
QH
QE
QF
ΔQs
NOA
-100
0
100
200
300
400
500
600
700
0 2 4 6 8 10 12 14 16 18 20 22 24
time (h) LST
W/m
2
Q*
QH
QE
QF
ΔQs
Q*- net all wave radiation
QH-sensible heat flux
QE-latent heat flux
QF-anthropogenic heat
ΔQs-heat storage
(urban, downtown)
(urban, at the harbor)
(semi-urban)
COST-728 Workshop on‘Model urbanization strategy’UKMO, Exeter, UK, 3-4 May 2007
7
Diurnal variation of sensible heat fluxDiurnal variation of sensible heat flux
• NOANOA : larger values due to : larger values due to
NOA
-50
0
50
100
150
200
250
300
350
400
0 2 4 6 8 10 12 14 16 18 20 22 24
time (h) LT
sen
sib
le h
est
flu
x (W
/m2 )
mesurements
Marousi
-50
0
50
100
150
200
250
300
350
400
0 2 4 6 8 10 12 14 16 18 20 22 24
time (h) LT
sen
sib
le h
eat
flu
x (W
/m2 )
measurements
soil characteristics (bare rocks) and surface cover (olive tree soil characteristics (bare rocks) and surface cover (olive tree plantation)plantation)
• MarousiMarousi: turbulence characteristics of the grove and not the surrounded built-up area: turbulence characteristics of the grove and not the surrounded built-up area
NOA
-50
0
50
100
150
200
250
300
350
400
0 2 4 6 8 10 12 14 16 18 20 22 24
time (h) LT
sen
sib
le h
eat
flu
x (W
/m2 )
MRF-urban
MRF
MRF-dyn
MRF-ther
Marousi
-50
0
50
100
150
200
250
300
350
400
0 2 4 6 8 10 12 14 16 18 20 22 24
time (h) LT
sen
sib
le h
eat
flu
x (W
/m2 )
MRF-urban
MRF
MRF-dyn
MRF-ther
Model results versus measurements
• MRFMRF: substantially higher values than the measurements : substantially higher values than the measurements
• MRF-urbanMRF-urban: in better agreement with the measurements: in better agreement with the measurements
Decrease
MANGE 40%
Decrease
MANGE 29%
Schemes intercomparison
• During the night:During the night: increase (absolute values) due to the ‘thermal’ part increase (absolute values) due to the ‘thermal’ part
• During the dayDuring the day: decrease due to the smaller temperature gradients produced by the ‘thermal’ part : decrease due to the smaller temperature gradients produced by the ‘thermal’ part and the zand the z00
Measurements (Batchvarova and Gryning, 1998)
temperature gradients (higher location)temperature gradients (higher location)
m
j ji
jijin
i OBS
OBSPRED
nmMANGE
1 ,
,,
1
1
PRED -predicted values
OBS -observed values
(Mean Absolute Normalized Gross Error)
COST-728 Workshop on‘Model urbanization strategy’UKMO, Exeter, UK, 3-4 May 2007
8
-300
-250
-200
-100
-50
-25
-20
-15
050100
150
200
250
300
350
400
450
500
W/m
2
Spatial distribution of the sensible heat fluxSpatial distribution of the sensible heat flux
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasNOA
M arousi
MRF
3:00 LST
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasNOA
M arousi
14:00 LSTMRF
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasNOA
M arousi
MRF-dyn
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasNOA
M arousi
MRF-dyn
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasNOA
M arousi
MRF-ther
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasNOA
M arousi
MRF-ther
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasNOA
M arousi
MRF-urban
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasNOA
M arousi
MRF-urban
COST-728 Workshop on‘Model urbanization strategy’UKMO, Exeter, UK, 3-4 May 2007
9 Diurnal variation of friction velocityDiurnal variation of friction velocity
• Max values ~0.5 m/s at both sites, although VMax values ~0.5 m/s at both sites, although VNOANOA (~4 m/s) > V (~4 m/s) > VMAROUSIMAROUSI (~2 m/s), due to its higher (~2 m/s), due to its higher
locationlocation
• Marousi:Marousi: the nonhomogeneity of the surrounding buildings, interchanged with the green areas the nonhomogeneity of the surrounding buildings, interchanged with the green areas cause higher valuescause higher values
NOA
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0 2 4 6 8 10 12 14 16 18 20 22 24
time (h) LT
fric
tion
vel
ocit
y (m
/s)
measurements
NOA
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0 2 4 6 8 10 12 14 16 18 20 22 24
time (h) LT
fric
tion
vel
ocit
y (m
/s)
MRF-urban
MRF
MRF-dyn
MRF-ther
Marousi
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0 2 4 6 8 10 12 14 16 18 20 22 24
time (h) LT
fric
tion
vel
ocit
y (m
/s)
mesurements
Decrease
MANGE 6%
Decrease
MANGE 2%
Marousi
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0 2 4 6 8 10 12 14 16 18 20 22 24
time (h) LT
fric
tion
vel
ocit
y (m
/s)
MRF-urban
MRF
MRF-dyn
MM58-ther
Measurements (Batchvarova and Gryning, 1998)Model results versus measurements
• During the night:During the night: any comparison with the measurements is meaningless (<0.1 m/s, the model’s any comparison with the measurements is meaningless (<0.1 m/s, the model’s threshold)threshold)
• During the day:During the day: decrease in the MRF-urban, closer to the measurementsdecrease in the MRF-urban, closer to the measurements
• MarousiMarousi: smaller decrease because the z: smaller decrease because the z00 did not change significantly. Higher values at noon due did not change significantly. Higher values at noon due
to the wind speed increase to the wind speed increase
Schemes intercomparison
• Differences due to the different profile functions and zDifferences due to the different profile functions and z00
• During the nightDuring the night: increase due to the increase of instability: increase due to the increase of instability
increase of z0
increase in the diffusion processes
decrease in the wind speed
increase of u*
normalization in temperature gradients
decrease of u*
decrease of u*• During the dayDuring the day::
COST-728 Workshop on‘Model urbanization strategy’UKMO, Exeter, UK, 3-4 May 2007
10
Spatial distribution of the friction velocitySpatial distribution of the friction velocity
MRF
3:00 LST
14:00 LSTMRF
MRF-dyn
MRF-dyn
MRF-ther
MRF-ther
MRF-urban
MRF-urban
m/s 0.
050.
100.
150.
200.
250.
300.
350.
400.
450.
500.
550.
600.
650.
700.
750.
800.
850.
900.
951.
00
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasN O A
M arousi
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasN O A
M arousi
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasN O A
M arousi
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasN O A
M arousi
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasN O A
M arousi
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasN O A
M arousi
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasN O A
M arousi
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasN O A
M arousi
COST-728 Workshop on‘Model urbanization strategy’UKMO, Exeter, UK, 3-4 May 2007
5
ResultsResults
Surface fluxesSurface fluxes
Air TemperatureAir Temperature
Diffusion coefficientsDiffusion coefficients
PBL heightPBL height
Surface fluxesSurface fluxes
Air TemperatureAir Temperature
COST-728 Workshop on‘Model urbanization strategy’UKMO, Exeter, UK, 3-4 May 2007
11 Diurnal variation of air temperature (at 10 m agl)Diurnal variation of air temperature (at 10 m agl)
MeasurementsMeasurements• During the night:During the night: development of an urban heat island development of an urban heat island
• During the day:During the day: lower maximum values at the urban stations (NOA and Peiraias), compared to lower maximum values at the urban stations (NOA and Peiraias), compared to the suburban station (Marousi)the suburban station (Marousi)
• MRF-urbanMRF-urban: decrease in the temperature amplitude wave, in better accordance with the : decrease in the temperature amplitude wave, in better accordance with the measurementsmeasurements
• NOANOA: differences with measurements due to its location on top of the hill, not resolved by the : differences with measurements due to its location on top of the hill, not resolved by the model’s spatial resolution (2 km) model’s spatial resolution (2 km)
NOA
20
22
24
26
28
30
32
34
36
0 2 4 6 8 10 12 14 16 18 20 22 24
time (h) LT
tem
pera
ture
(oC
)
measurements
Peiraias
20
22
24
26
28
30
32
34
36
0 2 4 6 8 10 12 14 16 18 20 22 24
time (h) LT
tem
pera
ture
(oC
)
measurements
Marousi
20
22
24
26
28
30
32
34
36
0 2 4 6 8 10 12 14 16 18 20 22 24
time (h) LT
tem
per
atu
re (o C
)
measurements
NOA
20
22
24
26
28
30
32
34
36
0 2 4 6 8 10 12 14 16 18 20 22 24
time (h) LT
tem
pera
ture
(oC
)
MRF-urban
MRF
MRF-dyn
MRF-ther
Marousi
20
22
24
26
28
30
32
34
36
0 2 4 6 8 10 12 14 16 18 20 22 24
time (h) LT
tem
per
atu
re (o C
)
MRF-urban
MRF
MRF-dyn
MRF-ther
Decrease
MANGE 53%
Decrease
MANGE 38%
Decrease
MANGE 41%
20
22
24
26
28
30
32
34
36
0 2 4 6 8 10 12 14 16 18 20 22 24
time (h) LT
tem
pera
ture
(oC
)
MRF-urban
MRF
MRF-dyn
MRF-ther
Schemes intercomparison
• During the nightDuring the night: increase due to the ‘thermal’ part
increase due to the ‘dynamical’ part
decrease due to the ‘thermal’ parttotal decrease • During the dayDuring the day::
Model results versus measurements
COST-728 Workshop on‘Model urbanization strategy’UKMO, Exeter, UK, 3-4 May 2007
12
Spatial distribution of the Spatial distribution of the air temperature (at 2m agl)air temperature (at 2m agl)
MRF-urban
MRF-urban
MRF-dyn - MRF
MRF-dyn - MRF
MRF-ther - MRF
MRF-ther - MRF
MRF-urban - MRF
MRF-urban - MRF
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
o C
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasN O A
M arousi
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasN O A
M arousi
ΔΤ
(oC
)
Spatial distribution of the air temperature Spatial distribution of the air temperature differences (at 2m agl)differences (at 2m agl)
3:00 LST
14:00 LST
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasN O A
M arousi
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasN O A
M arousi
-2.4
to
-2.
1
-2
.1 t
o -
1.8
-1
.8 t
o -
1.5
-1
.5 t
o -
1.2
-1
.2 t
o -
0.9
-0
.9 t
o -
0.6
-0
.6 t
o -
0.3
-0
.3 t
o 0
.0
0.
0 to
0.3
0.
3 to
0.6
0.
6 to
0.9
0.
9 to
1.2
1.
2 to
1.5
1.
5 to
1.8
1.
8 to
2.1
2.
1 to
2.4
2.
4 to
2.8
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasN O A
M arousi
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasN O A
M arousi
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasN O A
M arousi
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasN O A
M arousi
3:00 LST 3:00 LST 3:00 LST
14:00 LST 14:00 LST 14:00 LST
COST-728 Workshop on‘Model urbanization strategy’UKMO, Exeter, UK, 3-4 May 2007
5
ResultsResults
Surface fluxesSurface fluxes
Air TemperatureAir Temperature
Diffusion coefficientsDiffusion coefficients
PBL heightPBL height
Surface fluxesSurface fluxes
Air TemperatureAir Temperature
Diffusion coefficientsDiffusion coefficients
COST-728 Workshop on‘Model urbanization strategy’UKMO, Exeter, UK, 3-4 May 2007
13
Diffusion coefficient profilesDiffusion coefficient profiles
• During the day:During the day:
NOA3:00 LST
0
200
400
600
800
1000
1200
1400
1600
1800
2000
0.1 1 10
Diffusion coefficient (m2/s)
Hei
ght
(m)
agl
MRF-urban
MRF
MRF-dyn
MRF-ther
NOA14:00 LST
0
200
400
600
800
1000
1200
1400
1600
1800
2000
0 20 40 60 80 100 120 140 160 180 200 220
Diffusion coefficient (m2/s)
Hei
ght
(m)
agl
MRF-urban
MRF
MRF-dyn
MRF-ther
increase due to the ‘dynamical’ part
decrease due to the ‘thermal’ part total decrease
Schemes intercomparisonSchemes intercomparison• During the night:During the night: increase in the lower atmosphere due to the ‘dynamical’ and ‘thermal’ part increase in the lower atmosphere due to the ‘dynamical’ and ‘thermal’ part
COST-728 Workshop on‘Model urbanization strategy’UKMO, Exeter, UK, 3-4 May 2007
14
Spatial distribution of diffusion coefficients at the surface layerSpatial distribution of diffusion coefficients at the surface layer
MRF
3:00 LST
14:00 LSTMRF
MRF-dyn
MRF-dyn
MRF-ther
MRF-ther
MRF-urban
MRF-urban
246810121416182022242628303234363840424446
m2/s
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasN O A
M arousi
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasN O A
M arousi
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasN O A
M arousi
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasN O A
M arousi
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasN O A
M arousi
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasN O A
M arousi
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasN O A
M arousi
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasN O A
M arousi
COST-728 Workshop on‘Model urbanization strategy’UKMO, Exeter, UK, 3-4 May 2007
5
ResultsResults
Surface fluxesSurface fluxes
Air TemperatureAir Temperature
Diffusion coefficientsDiffusion coefficients
PBL heightPBL height
Surface fluxesSurface fluxes
Air TemperatureAir Temperature
Diffusion coefficientsDiffusion coefficients
PBL heightPBL height
COST-728 Workshop on‘Model urbanization strategy’UKMO, Exeter, UK, 3-4 May 2007
15 Diurnal variation of the PBL heightDiurnal variation of the PBL height
Schemes intercomparisonSchemes intercomparison• During the nightDuring the night: increase due to the ‘thermal’ part: increase due to the ‘thermal’ part
NOA
0
200
400
600
800
1000
1200
1400
1600
1800
2000
2200
2400
2600
0 2 4 6 8 10 12 14 16 18 20 22 24
time (LST)
m
MRF
MRF-urban
MRF-dyn
MRF-ther
Marousi
0
200
400
600
800
1000
1200
1400
1600
1800
2000
2200
2400
2600
0 2 4 6 8 10 12 14 16 18 20 22 24
time (LST)
m
MRF
MRF-urban
MRF-dyn
MRF-ther
NOA
0
200
400
600
800
1000
1200
1400
1600
1800
2000
2200
2400
2600
0 2 4 6 8 10 12 14 16 18 20 22 24
time (LST)
m
Blackadar
Gayno-Seaman
Pleim-Xiu
Marousi
0
200
400
600
800
1000
1200
1400
1600
1800
2000
2200
2400
2600
0 2 4 6 8 10 12 14 16 18 20 22 24
time (LST)
m
Blackadar
Gayno-Seaman
Pleim-Xiu
increase due to the ‘dynamical’ part
decrease due to the ‘thermal’ parttotal decrease
• Delay (~1 h) in max value (MRF-urban), due to the delay in the sea-breeze developmentDelay (~1 h) in max value (MRF-urban), due to the delay in the sea-breeze development
• During the dayDuring the day::
COST-728 Workshop on‘Model urbanization strategy’UKMO, Exeter, UK, 3-4 May 2007
16 Diurnal variation of the PBL heightDiurnal variation of the PBL height
NOA
0
200
400
600
800
1000
1200
1400
1600
1800
2000
2200
0 2 4 6 8 10 12 14 16 18 20 22 24
time (LST)
Hei
ght
(m)
agl
IBL measurements
MRF-urban
MRF
Gayno-Seaman
Blackadar
Pleim-Xiu
max kv
Tombrou et al. (2006)
Penteli (rural station)
0
200
400
600
800
1000
1200
1400
1600
1800
2000
2200
0000 0300 0600 0900 1200 1500 1800 2100 0000
time (LST)
Hei
ght
(m)
agl
exp
MRF-urban
MRF
Gayno-Seaman
Pleim-Xiu
Blackadar
kv (middle)
20-9-2002
15-9-1994
Zografou (suburban station)
0
200
400
600
800
1000
1200
1400
1600
1800
2000
2200
0 2 4 6 8 10 12 14 16 18 20 22 24
time (LST)
hei
ght
(m)
agl
mesurements
MRF-urban
MRF
Gayno-Seaman
Blackadar
Pleim-Xiu
kv (middle)
20-9-2002
COST-728 Workshop on‘Model urbanization strategy’UKMO, Exeter, UK, 3-4 May 2007
17
Spatial distribution of the PBL heightSpatial distribution of the PBL height
MRF
3:00 LST
14:00 LSTMRF
MRF-dyn
MRF-dyn
MRF-ther
MRF-ther
MRF-urban
MRF-urban
m
50100
150
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
2000
2100
2200
2300
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasN O A
M arousi
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasN O A
M arousi
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasN O A
M arousi
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasN O A
M arousi
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasN O A
M arousi
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasN O A
M arousi
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasN O A
M arousi
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasN O A
M arousi
COST-728 Workshop on‘Model urbanization strategy’UKMO, Exeter, UK, 3-4 May 2007
18 Summarizing the resultsSummarizing the results
5 1 0 1 5 2 0 2 5 3 0 3 5 4 0 4 5 5 0 5 5
( x 2 k m )
5
1 0
1 5
2 0
2 5
3 0
3 5
4 0
4 5
(x 2
km)
nt
MRFMRFurbantherMRFdynnt
,,11
n=77 (number of grids)
t=12 (number of hours for the day and night)
Day(0700-1800 LST)
MRF-dynall - MRF(%)
MRF-ther - MRF(%)
MRF-urban - MRF(%)
Sensible heat -1.92 -28.15 -28.99
Friction velocity
-3.98 -10.84 -10.79
Air temperature
+2.10 -15.21 -9.12
Diffusion coefficients
+36.58 -34.58 -20.97
Wind speed +6.87 -4.85 -6.47
PBL height +10.45 -10.47 -5.11
Night(0000-0600 LST,
1900-2300 LST)
MRF-dynall - MRF(%)
MRF-ther - MRF(%)
MRF-urban - MRF(%)
Sensible heat -3.38 -47.70 -51.79
Friction velocity
+1.19 +7.69 +7.65
Air temperature
+1.08 +3.80 +4.03
Diffusion coefficients
+10.21 +5.30 +83.9
Wind speed +0.53 +64.90 +60.06
PBL height +5.95 +86.40 +88.30
COST-728 Workshop on‘Model urbanization strategy’UKMO, Exeter, UK, 3-4 May 2007
19
m/s
0.250.500.751.001.251.501.752.002.252.502.753.003.253.503.754.004.254.504.755.005.255.506.00
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasN O A
M arousi
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasN O A
M arousi
MRF-urban
14:00 LST
3:00 LST
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Peira iasN O A
M arousi
Thrakom akedones
14:00 LST
-1 .50 to -1 .25
-1 .25 to -1 .00
-1 .00 to -0 .75
-0 .75 to -0 .50
-0 .50 to -0 .25
-0 .25 to 0.00
0.00 to 0.25
0.25 to 0.50
0.50 to 0.75
0.75 to 1.00
1.00 to 1.25
1.25 to 1.50
1.50 to 1.75
1.75 to 2.00
2.00 to 2.25
2.25 to 2.50
2.50 to 2.75
2.75 to 3.00
m/s
5 10 15 20 25 30 35 40 45 50 55
(x 2km )
5
10
15
20
25
30
35
40
45
(x 2
km)
Pe ira iasN O A
M arousi
Thrakom akedones
3:00 LST
Spatial distribution of the wind Spatial distribution of the wind velocity (at 10 m)velocity (at 10 m)
MRF-urban
Spatial distribution of the wind speed Spatial distribution of the wind speed differences (at 10m)differences (at 10m)
MRF-urban – MRF-not urban
MRF-urban – MRF-not urban
COST-728 Workshop on‘Model urbanization strategy’UKMO, Exeter, UK, 3-4 May 2007
20
Vertical cross sections of the wind velocity along the sea-breeze axisVertical cross sections of the wind velocity along the sea-breeze axis
m/s
MRF-urban
0
500
1000
1500
2000
2500
m (
agl)
PeiraiasÍ Ï Á
Marousi
Thrakomakedones
57000 m
MRF-not urban
14:00 LST
0.250.500.751.001.251.501.752.002.252.502.753.003.253.503.754.004.254.504.755.005.255.506.00
0
500
1000
1500
2000
2500
m (
agl)
PeiraiasÍ Ï Á
Marousi
Thrakomakedones
57000 m
0
500
1000
1500
2000
2500
m (
agl)
PeiraiasÍ Ï Á
Marousi
Thrakomakedones
57000 m
14:00 LST
3:00 LST
0
500
1000
1500
2000
2500
m (
agl)
PeiraiasÍ Ï Á
Marousi
Thrakomakedones
57000 m
3:00 LST
0.4
m/s
4 m/s
COST-728 Workshop on‘Model urbanization strategy’UKMO, Exeter, UK, 3-4 May 2007
21
ConclusionsConclusions
Both modifications play an important role and improve the model’s resultsBoth modifications play an important role and improve the model’s results
During the day:During the day:
• The increase in The increase in temperaturetemperature and and diffusion coefficientsdiffusion coefficients calculated calculated by the ‘dynamical’ part is compensated by the decrease in the by the ‘dynamical’ part is compensated by the decrease in the ‘thermal’ part, resulting in a total decrease‘thermal’ part, resulting in a total decrease
• A decrease in A decrease in turbulenceturbulence and and fluxesfluxes is calculated by both is calculated by both modificationsmodifications
• A slowing in the sea-breeze front and a frictional retard A slowing in the sea-breeze front and a frictional retard concerning its penetration over the Athens city is calculated due concerning its penetration over the Athens city is calculated due to the increased roughness lengthto the increased roughness length
During the night:During the night:
• The total increase in The total increase in temperaturetemperature, , diffusion coefficientsdiffusion coefficients, , turbulenceturbulence and and fluxesfluxes is due to both modifications is due to both modifications
• The maximum The maximum wind speedswind speeds calculated in the lower atmosphere is calculated in the lower atmosphere is due to the urban heat islanddue to the urban heat island