integrating in situ and satellite observations with geos...
TRANSCRIPT
Integrating in situ and satellite observations with GEOS-Chem to constrain the influence of
boreal biomass burning emissions on tropospheric oxidant chemistry
Mark Parrington, Paul Palmer (University of Edinburgh)and the BORTAS Science Team
Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites (BORTAS): 12 July - 3 August 2011
BORTAS sampled a wide age spectra of plumes!
Serendipity puts BORTAS in a unique position !
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0 7 14 21
Resulting perturbation to atmospheric chemistry in the troposphere.!
Composition and distribution of biomass burning outflow!
O3 production and loss within the outflow!
BORTAS addresses the science by integrating different and modelling techniques!
Resulting perturbation to atmospheric chemistry in the troposphere.!
Composition and distribution of biomass burning outflow!
O3 production and loss within the outflow!
BORTAS addresses the science by integrating different and modelling techniques!
• Wide range of biomass burning plume ages sampled by BORTAS from ground-based, in situ and satellite measurements.
• Integrated modelling approach required to fully interpret data --> high resolution GEOS-Chem and adjoint simulations nested over the North Atlantic region
Resulting perturbation to atmospheric chemistry in the troposphere.
C o m p o s i t i o n a n d distribution of biomass burning outflow
O3 production and loss within the outflow
Palmer et al., ACPD, 2013
GEOS-Chem North Atlantic nested grid• North Atlantic nested grid with boundary conditions from 2×2.5 global simulation.• Daily biomass burning emissions from FLAMBE inventory scaled down by factor of 2 (Alvarado et
al. 2010, Fisher et al. 2010, and Parrington et al. 2012).
Nested grid output at 750 hPa: 1700
UTC, 18 July 2011.
CO
40oN
45oN
50oN
55oN
60oN
80oW 60oW 40oW 20oW
50 100 150 200 [ppbv]
Ox
40oN
45oN
50oN
55oN
60oN
80oW 60oW 40oW 20oW
20 40 60 80 [ppbv]
NOy
40oN
45oN
50oN
55oN
60oN
80oW 60oW 40oW 20oW
0.00 0.75 1.50 2.25 [ppbv]
NOx
40oN
45oN
50oN
55oN
60oN
80oW 60oW 40oW 20oW
0.00 0.05 0.10 0.15 [ppbv]
CO Ox
NOy NOx
Aircraft flight track (next slide)Met. fields and
emissions available from mid-2005
through to end of 2011
GEOS-Chem vs. BORTAS aircraft measurements, 18 July 2011
199.6 199.7 199.8 199.9 200.0Time / day of year 2011
0
2
4
6
8
10
GPS
alti
tude
/ km
BORTAS flight b621: BAe-146 CO ; CTM CO
199.6 199.7 199.8 199.9 200.0Time / day of year 2011
0
100
200
300
400
500
600
700
CO /
ppbv
BORTAS flight b621: BAe-146 TECO49 O3 ; CTM O3
199.6 199.7 199.8 199.9 200.0Time / day of year 2011
0
20
40
60
80
100
120
TECO
49 O
3 / p
pb
BORTAS flight b621: BAe-146 LIF total NOy; CTM NOy
199.6 199.7 199.8 199.9 200.0Time / day of year 2011
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
LIF
tota
l NO
y / U
NK
NO
WN
BORTAS flight b621: BAe-146 LIF NOx ; CTM NOx
199.6 199.7 199.8 199.9 200.0Time / day of year 2011
0.0
0.1
0.2
0.3
0.4
LIF
NO
x / p
pbv
BORTAS flight b621: BAe-146 SP2 BC mass; CTM BC Hydr
199.6 199.7 199.8 199.9 200.0Time / day of year 2011
0.0
0.2
0.4
0.6
0.8
SP2
BC m
ass /
UN
KN
OW
N
Aircraft altitude CO O3
NOy NOx Black Carbon
Time / day of year 2011
GPS
altit
ude
/ km
CO /
ppb
v
O 3 /
ppb
v
NOy /
ppb
v
NOx /
ppb
v
BC m
ass
conc
entr
atio
n / μg
m-3
Evaluate O3 sensitivity to model inputs using differences between model and measurements.
Model Ox sensitivity to NOx emissions sources
Biomass burning
35oN40oN45oN50oN55oN60oN65oN70oN75oN
120oW 90oW 60oW 30oW
Lightning
35oN40oN45oN50oN55oN60oN65oN70oN75oN
120oW 90oW 60oW 30oW
Anthropogenic
35oN40oN45oN50oN55oN60oN65oN70oN75oN
120oW 90oW 60oW 30oW
Aircraft + Biofuel + Soil
35oN40oN45oN50oN55oN60oN65oN70oN75oN
120oW 90oW 60oW 30oW
0.0 1.0 2.0 [×10-4]
Biomass Burning Lightning
Anthropogenic Aircraft/biofuel/soil
Recall: the adjoint model provides a computationally efficient calculation of the sensitivity of the output of a model to its inputs through the partial derivatives.
July 2011 adjoint sensitivity of model Ox at
3 ozonesonde launch sites in Maritime Canada (▲) to North American
continental NOx emissions sources.
Sensitivity to biomass burning emissions smaller
than to anthropogenic sources but distinct
geographical distribution.
(dJ/dOx)/max(dJdOx)
35oN
40oN
45oN
50oN
55oN
60oN
65oN
100oW 80oW 60oW 40oW
-0.00 0.50 1.00
(dJ/dNOx)/max(dJdOx)
35oN
40oN
45oN
50oN
55oN
60oN
65oN
100oW 80oW 60oW 40oW
-2.71e-05 1.86e-03 3.75e-03
4D-variational assimilation of BORTAS aircraft O3 measurements
Cost function defined at each model chemistry time-step:
Normalised gradient of cost function with respect to initial model concentrations of Ox and NOx shows sensitivity along air mass trajectory upwind from measurements:
Difference between model and measured mixing ratio Sobs = representativeness error (50%)
+ measurement error (~5%)
Control vector defined as initial model tracer concentrations
= mean aircraft O3 “observation operator”
∂J/∂[NOx]apriori, 750-500 hPa average∂J/∂[Ox]apriori, 750-500 hPa average
(dJ/dOx)/max(dJdOx)
35oN
40oN
45oN
50oN
55oN
60oN
65oN
100oW 80oW 60oW 40oW
-0.00 0.50 1.00
(dJ/dNOx)/max(dJdOx)
35oN
40oN
45oN
50oN
55oN
60oN
65oN
100oW 80oW 60oW 40oW
-2.71e-05 1.86e-03 3.75e-03
4D-variational assimilation of BORTAS aircraft O3 measurements
Cost function defined at each model chemistry time-step:
Normalised gradient of cost function with respect to initial model concentrations of Ox and NOx shows sensitivity along air mass trajectory upwind from measurements:
Difference between model and measured mixing ratio Sobs = representativeness error (50%)
+ measurement error (~5%)
Control vector defined as initial model tracer concentrations
= mean aircraft O3 “observation operator”
∂J/∂[NOx]apriori, 750-500 hPa average∂J/∂[Ox]apriori, 750-500 hPa average
45
60
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3000 4000 5000 6000
5000
NOAA HYSPLIT MODEL Backward trajectories ending at 1800 UTC 18 Jul 11
GDAS Meteorological Data
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Job ID: 11186 Job Start: Wed May 8 15:19:23 UTC 2013 Source 1 lat.: 44.812000 lon.: -64.525000 height: 5000 m AGL Trajectory Direction: Backward Duration: 24 hrs Vertical Motion Calculation Method: Model Vertical Velocity Meteorology: 0000Z 15 Jul 2011 - GDAS1
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Summary• The BORTAS measurement campaign in the summer of 2011
sampled biomass burning smoke plumes with a wide range of ages.• measurements of key tracers associated with biomass burning made
from variety of ground-based, airborne, and satellite instruments.
• http://www.atmos-chem-phys-discuss.net/special_issue165.html
• GEOS-Chem nested grid for North Atlantic region links transport of biomass burning plumes between North America and Europe.
• Adjoint sensitivity calculations indicate model O3 sensitivity to precursor emissions and distributions.
Next steps• Assimilate BORTAS aircraft measurements into North Atlantic
nested grid to constrain model oxidant chemistry and scale-up measurements to evaluate broader regional impact.
• Assimilate satellite observations over the BORTAS campaign period to test consistency between different measurements of biomass burning outflow.