Embed Size (px)
Citation preview
Global budget of tropospheric ozone:
long-term trend and recent model advances
Lu Hu
With
Loretta Mickley, Daniel Jacob, Xiong Liu,
Patrick Kim, Yi Zhang, Lin Zhang, Bob
Yantosca, Melissa Sulprizio
Acknowledgement: WOUDC, NOAA-GMD, MOZAIC-IAGOS,
NASA GMAO, ACMAP, and Aura Science Team
GEOS-Chem updates in past decade have led to more active tropospheric ozone chemistry
Global tropospheric ozone budget in GEOS-Chem benchmark outputs
Model release date
Changes mainly reflect model advances, not the actual atmosphere
Hu et al. Atmos. Environ., in review
GEOS-Chem updates in past decade have led to more active tropospheric ozone chemistry
Global tropospheric ozone budget in GEOS-Chem benchmark outputs
Model release date
Changes mainly reflect model advances, not the actual atmosphere
Hu et al. Atmos. Environ., in review
Hu et al. Atmos. Environ., in review
GEOS-Chem v10-01 provides the best simulation of global tropospheric ozone over the history of the GEOS-Chem model versions
Model
Mean 500 hPa ozone in JJA 2013
OMI satellite data, X. Liu, SAO
GEOS-Chem v10-01 provides the best simulation of global tropospheric ozone over the history of the GEOS-Chem model versions
But, GEOS-Chem shows a negative bias relative to ozonesondes at high northern latitudes, also a large sensitivity to meteorological fields
Model
Mean 500 hPa ozone in JJA 2013
Hu et al. Atmos. Environ., in review
Pre
ssu
re (
hP
a)
Ozone (ppbv)
Ozonesonde GEOS-5 (0.25° aka GEOS-FP) GEOS-5 (0.5°) GEOS-4 (1°)
OMI satellite data, X. Liu, SAO
Pre 2000 Post 2010
200
250
300
350
IPCCTAR ACCENT ACCMIP IPCCAR5
Burden
(Tg)
2000
3000
4000
5000
6000
IPCCTAR ACCENT ACCMIP IPCCAR5
Chem
icalproduction(Tg/y)
200
400
600
800
1000
IPCCTAR ACCENT ACCMIP IPCCAR5
Netstratosphericinflux(Tg/y)
Tropospheric ozone budget in current models B
urd
en
(Tg
) C
he
mic
al p
rod
uct
ion
(T
g/y)
Stra
tosp
her
e-tr
op
osp
her
e
exch
ange
(Tg
/y)
Hu et al. Atmos. Environ., in review
Pre 2000 Post 2010
200
250
300
350
IPCCTAR ACCENT ACCMIP IPCCAR5
Burden
(Tg)
2000
3000
4000
5000
6000
IPCCTAR ACCENT ACCMIP IPCCAR5
Chem
icalproduction(Tg/y)
200
400
600
800
1000
IPCCTAR ACCENT ACCMIP IPCCAR5
Netstratosphericinflux(Tg/y)
Tropospheric ozone budget in current models
GEOS-Chem
Bu
rde
n (
Tg)
Ch
em
ical
pro
du
ctio
n
(Tg/
y)
Stra
tosp
her
e-tr
op
osp
her
e
exch
ange
(Tg
/y)
Hu et al. Atmos. Environ., in review
Pre 2000 Post 2010
200
250
300
350
IPCCTAR ACCENT ACCMIP IPCCAR5
Burden
(Tg)
2000
3000
4000
5000
6000
IPCCTAR ACCENT ACCMIP IPCCAR5
Chem
icalproduction(Tg/y)
200
400
600
800
1000
IPCCTAR ACCENT ACCMIP IPCCAR5
Netstratosphericinflux(Tg/y)
Tropospheric ozone budget in current models
HO2 +NOStratosphere
troposphereexchange
CH3O2 +NO
RO2 +NO
Sources
O(1D)+H2O
HO2+O3
OH+O3
Dry
deposition
HOBr+hvOthers
Sinks
GEOS-Chem
Bu
rde
n (
Tg)
Ch
em
ical
pro
du
ctio
n
(Tg/
y)
Stra
tosp
her
e-tr
op
osp
her
e
exch
ange
(Tg
/y)
Hu et al. Atmos. Environ., in review
Increasingly active tropospheric chemistry in models would affect the computed sensitivity to perturbations
Parrish et al., 2014
Climate models
Observations Observations
Model
GEOS-Chem simulation with MERRA+MACCity
Hu et al. in prep
O3 (
pp
bv)
Models can reproduce present-day levels, but not multi-decadal trends
A widespread model ozone overprediction in 1980s O
3 (
pp
bv)
Hu et al. in prep
Model estimates of natural background ozone is way too high, not only in 1920s, but also 1980s …
Hu et al. in prep
Observations
Model
If no anthropogenic emissions in the model
Nature sources
Parrish et al., 2014
Climate models
Observations Observations
Model
GEOS-Chem simulation with MERRA+MACCity
Hu et al. in prep
O3 (
pp
bv)
If no anthropogenic emissions in the model
Need to reduce global NOx emission in 1980s by half?
