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Long-term simulation of photochemistry in the Grenoble urban area using a mesoscale model chain
including MM5, CHIMERE and MetPhoMod
Eric Chaxel*, Jean-Pierre Chollet*, Christophe Quiniou** and Olivier Couach***
* Laboratory of Geophysical and Industrial Flows, THEO, Grenoble (France)
** GIERSA, 44 avenue Marcelin Berthelot, Grenoble* LPAS, EPFL, Lausanne (Switzerland)
Contact: eric.chaxel@hmg.inpg.frWebsite: http://www.prevalp.fr.fm
Workshop CHIMERE, 23rd March 2005
2/23
Outline
• Framework of the study
• Description of the modelling chain
• Two highlights: – Evaluation of nested CHIMERE simulation for the summer
2003 (June-August) in Rhône-Alpes region– Impact of long range transport shown by CHIMERE in July
1999 on Grenoble photochemistry
• Discussion
3/23
Framework• In assistance to local air quality agency
ASCOPARG:– to assess emission reduction scenario– To develop a modelling chain able to correctly
predict ozone events
• In a scientific context: project PARAMET (Photochemistry and Aerosols in Alpine Region: Mixing and Transport– Model the processes responsible for high ozone
events in narrow valleys: slope winds, inversion layers, recirculation
– Evaluate the impact of regional transport in the valleys of Grenoble, Maurienne and Chamonix
4/23
Our use of CHIMERE• CHIMERE is used at boundaries of an other model:
MetPhoMod (LPAS, EPFL, Lausanne)
• Since CHIMERE has never been validated in very complex terrain our use of the model is limited to 2 regional scales:– Continental for calculate background concentration in the
Alps– Regional to account for main cities (Lyon, Geneva,
Marseille, Torino) contributing to regional ozone
• A “beta test” simulation at a 2-km resolution has been recently evaluated
5/23
Description of the modeling chain
NCEP/AVN forecastsΔx = 100 km, Δt = 6 hours
MM5Δx = 18 km
CHIMEREΔx = 18 km
MM5Δx = 6 km
CHIMEREΔx = 6 km
MetPhoMod
Δx = 2 km(meteo + chimie)
EMEP inventoryΔx = 50 km
CITEPA inventoryΔx = 6 km
GIERSA inventoryΔx = 1 km
Post-processingΔt = 1 hour
One-way nesting
Two-way nesting
Inputs/outputs
6/23
Technical schematic of the chain
Annual inventoryNOx, COV, CO, SO2
ASCII files
Annual inventoryNOx, COV, CO, SO2
ASCII files
Gridded hourly emissionsRACM or MELCHIOR
speciationNetCDF files
Gridded hourly emissionsRACM speciesNetCDF files
MetPhoMod
CHIMERE
MM5
ECMWF
GIS GIERSA
prep
Cad
astr
e
CA
DA
ST
RE
prepemis
Interfaces 3d modelsTemporary
files
Legend
TONETCDF + TOMETPH
prepemis_cdf
chimere2racm
7/23
Results for the summer 2003
• CHIMERE runs on 6 15-day periods:– 1 to 15 June
– 16 to 30 June
– 1 to 15 July
– 16 to 31 July
– 1 to 15 August (Heat wave period)
– 16 to 31 August
NCEP/AVN forecastsΔx = 100 km, Δt = 6 hours
MM5Δx = 18 km
CHIMEREΔx = 18 km
MM5Δx = 6 km
CHIMEREΔx = 6 km
MetPhoMod
Δx = 2 km(meteo + chimie)
EMEP inventoryΔx = 50 km
CITEPA inventoryΔx = 6 km
GIERSA inventoryΔx = 1 km
Post-processingΔt = 1 hour
One-way nesting
Two-way nesting
Inputs/outputs
8/23
Summer 2003: an high ozone summer
0
50
100
150
200
250
01-juin 08-juin 15-juin 22-juin 29-juin 06-juil 13-juil 20-juil 27-juil 03-août 10-août 17-août 24-août
Charavines Versoud Champ sur Drac Fontaine Les Balmes St Martin d'Heres
Grenoble Les Frenes seuil information seuil EU Casset
Daily ozone maximum (μg/m3) measured by ASCOPARG from 1st June to 31st August 2003.
Heat wave
Many exceedance days of the treshold 180 μg/m3 (seuil information)
60
70
80
90
100
110
120
130
140
150
01-juin 08-juin 15-juin 22-juin 29-juin 06-juil 13-juil 20-juil 27-juil 03-août 10-août 17-août 24-août 31-août
Ozo
ne
(m
icro
g/m
3)
1-week average 2000
1-week average 2001
1-week average 2003
Background level of ozone measured at le Casset (alt. 1800 m) in summer 2000, 2001 and 2003
Background O3 level at le Casset (alt. 1800 m)
Heat wave 2003
A net increasing trend is observed over the summer 2003
General trend over the summer
9/23
Stations used for validation
Meteorological ground station
Ground station with O3/NOx meas.
CHIMERE regional domain40*40 cellsdx = 8 km8 vertical levels
MetPhoMod domain36*58 cellsdx = 2 km24 vertical levels
Lyon
Grenoble
45 AQ stations:O3, NO, NO2
35 meteo stations:U, V, RH, T, Ray
10/23
CHIMERE dx = 6 km
Hourly measurement
1 2 3 4 5 6 7 8 9 10 11 12 13 14
August 2003
Results of CHIMERE at 6 km resolutionfor hourly ozone
Hourly measurements are compared with model results at all stations
11/23
Some results of MM5 at 6 km resolution
1. MM5 at a 6-km resolution underestimates the daily maximum for 2-m temperatureat the sites located in valleys
2. This effect is observed at all sites during the heat wave (1st to 15th August 2003)
12/23
Results of CHIMERE at 6 km resolutionfor daily ozone maximum
0,00
2,00
4,00
6,00
8,00
10,00
12,00
14,00
16,00
18,00
1 to 16 June 16 to 30June
1 to 16 July 16 to 31 July 1 to 16August
16 to 31August
Eté 2003
Mea
n E
rro
r (m
icro
g/m
3)
Mean error over the summer 2003 at 45 sites: 12.7 μg/m3
0,00
5,00
10,00
15,00
20,00
25,00
Ann
ecy-
Nov
el
Ann
ecy-
Love
rchy
Bar
by
Cha
mbe
ry-P
aste
ur
St-
Jean
-de-
Mne
Cha
mbe
ry-le
-Hau
t
Cas
set
St-
Exu
pery
Alb
ertv
ille
Cha
mpa
gnie
r
Gre
nobl
e-le
s-F
rene
s
Rou
ssillo
n
Roa
nne
Tho
non
Cha
ravi
nes
Roc
hes-
de-C
ondr
ieu
Gen
as
Ann
emas
se
All
site
s
Lyon
-St-
Just
Ter
nay
Val
ence
-Cen
tre
Firm
iny
Ville
urba
nne-
Cro
ix-L
uize
t
Val
ence
-Sud
Cha
mon
ix
St-
Etie
nne-
Sud
St-
Etie
nne-
Cou
bert
in
Fon
tain
e-le
s-B
alm
es
Gai
llard
St-
Cha
mon
d
Vea
uche
Lyon
-Ger
land
Ver
soud
Sab
lons
Die
me
Ann
onay
St-
Mar
tin-d
-Her
es
Cha
mp-
sur-
Dra
c
Die
ulef
it
Mea
n E
rro
r (m
icro
g/m
3)
Mean bias over the summer 2003 at 45 sites : - 6.0 μg/m3 (model - obs)
13/23
Use of CHIMERE to constraint a other model: MetPhoMod
NCEP/AVN forecastsΔx = 100 km, Δt = 6 hours
MM5Δx = 18 km
CHIMEREΔx = 18 km
MM5Δx = 6 km
CHIMEREΔx = 6 km
MetPhoMod
Δx = 2 km(meteo + chimie)
EMEP inventoryΔx = 50 km
CITEPA inventoryΔx = 6 km
GIERSA inventoryΔx = 1 km
Post-processingΔt = 1 hour
One-way nesting
Two-way nesting
Inputs/outputs
?Why ?To provide realistic forcing compulsory for long term simulations (several months)
14/23
Use of CHIMERE to constraint a fine scale model: MetPhoMod
• Problems and questions:– How evaluate the quality of forcing by MM5 and CHIMERE ?– Model have different horizontal meshes
Lambert, dx = 6 km/ Lambert 2 Etendu, dx = 2 km– Model have different vertical descriptions
8 hybrid sigma levels/ 24 cartesian levels– Models have different chemical mechanisms
MELCHIOR/ RACM
• Solutions:– Perform comparison with 3D and ground data– Perform horizontal interpolation– Perform vertical interpolation– Using only common species to both mechanisms
15/23
Correspondance between MELCHIOR and RACM
Nom MELCHIOR
Description MELCHIOR
Nom RACM Description RACM
O3 ozone O3 ozone NO2 nitrogen dioxide NO2 nitrogen dioxide NO nitric oxide NO nitric oxide
PAN peroxyacetyl nitrate PAN peroxyacetyl nitrate ans higher saturated PANs HNO3 nitric acid HNO3 nitric acid SO2 sulfur dioxide SO2 sulfur dioxide CO carbon monoxide CO carbon monoxide CH4 methane CH4 methane C2H6 ethane ETH ethane
NC4H10 n-butane HC5 alkanes, alcohols, esters and alkynes with HO rate
between 3.4*10-12 and 6.8*10-12 cm3 s-1 C2H4 ethene ETE ethene C3H6 propene OLT terminal alkenes OXYL o-xylene TOL toluene and less reactive aromatics C5H8 isoprene ISO isoprene
APINEN α-pinene API α-pinene and other cyclic terpenes with one double
bonds HCHO formaldehyde HCHO formaldehyde
CH3CHO acetaldehyde ALD acetaldehyde and higher aldehydes GLYOX glyoxal GLY glyoxal
MGLYOX methyl glyoxal MGLY methylglyoxal and other α-carbonyl aldehydes CH3COE methyl ethyl ketone KET ketones
Table : correspondance between MELCHIOR and RACM species
20 species from CHIMERE are related to RACM species
16/23
Validation of CHIMERE forcing using 3D data from 25-27 July 1999
The CHIMERE model is used at boundaries of MetPhoMod
Validation of this forcing using data from POI 1 of GRENOPHOT 99
UHF radar and Lidar are located in Vif (south of Grenoble)
CHIMERE domain
MetPhoMod domain
UHF radar
windprofiler
Grenoble
Vif
17/23
Chartreuse rangeDévoluy range La Mure
Grenoble
Synoptic wind
Valley wind
Night valley wind in Grenoble by northerly synoptic wind
27 July 1999 00UT
N
S
Typical stratified atmosphere:#1: 0 - 400 m agl: ground-influenced layer#2: 400 - 2000 m agl : Thermic layer #3: 2000 m agl - ~: Synoptic regime
18/23
Validation of the MM5 forcing using UHF radar
Both synoptic and valley winds are correctly described by MetPhoMod forced with MM5
Strong synoptic southerly wind blows on 27th July 1999
Altitude amsl
Altitude amsl
Altitude amsl
1
2
3 ?
Low speeds = max. ozone production
Wind shears = transition zones with low speeds
19/23
Validation of the chemical forcing using LIDAR data
Long range transportassociated with
southerly wind
Long range transport as described by CHIMERE
• CHIMERE provides a good description of the synoptic situation (above 2500 m amsl)• The long range transport is well detected by CHIMERE but slightly underestimated (140
μg/m3 modelled versus 160 μg/m3 measured) • MM5 forcing provides southerly wind reaching too early the MetPhoMod domain• The valley bottom is more affected by sourtherly winds in the simulation than on radar
profiles
Altitude amsl Altitude amsl
Transition zone with max.
ozone production
20/23
Long range transport of ozone on July 27th 1999
Marseille (H-12)
Turin (H-36)
Backward trajectories reaching Grenoble on July 27th at 12UT shows that:
• the switch from northeasterly to southerly wind occured during the evening on July 26th
• air mass travelled over Marseille on July 26th
• air mass travelled over the Pô valley on July 25th
Very particular circulation leading to long range transport of ozone
Grenoble(July 27th, 12UT)
21/23
A try at a 2-km resolution
windprofiler
MM5 (dx = 2 km) correctly describes the local wind system on the period 25-27 July 1999
but.. CHIMERE underestimates ozone production compare with measurements
MM5
Grenoble
22/23
Discussion (1/2)• For our applications CHIMERE at a 6-km resolution
provides good synoptic/regional forcing (mean error of 10 μg/m3 on daily maximum)
• For a use at small scale several points should be/are in development in MM5:– Better impact of the topography on flows in MM5 such as
impact on slopes on incoming solar radiation (improvements in version 3.7)
– Description of the PBL in MM5: actual parameterisations are not adapted to complex terrain (problems on slopes)
– Vertical mesh should be refined near the PBL top to well detect the thermic layer (#2)
23/23
Discussion (2/2)
• For a use at small scale several points should be/are in development in CHIMERE:– Use a domain top higher than 500 hPa in CHIMERE– The number of layers should be increased in our simulations
(> 8)– Vertical mesh has to be refined near the ground to well
account for transport by valley winds (layer #1 is 400 m agl at night and 2000 m agl during the day)
– The thickness of the layers near the transition zones (wind shears) are of major importance
– In Grenoble case the reservoir layer is formed at 1800 m agl
Thanks for your attention!
Further information available at:
http://www.legi.hmg.inpg.fr/~Alpes/Internet