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A multi-platform analysis of the North American reactive nitrogen budget during the ICARTT summer intensive. - PowerPoint PPT Presentation
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R C Hudman, D J Jacob, S Turquety, L Murray, S Wu, Q Liang,A Gilliland, M Avery, T H Bertram, E Browell, W Brune, R C Cohen, J E Dibb, F M Flocke, J
Holloway, A Newman, X Ren, T B Ryerson, G W Sachse, H B Singh, P J Wooldridge
A multi-platform analysis of the North American reactive nitrogen budget during the ICARTT summer intensive
Friday, December 9, 2005 AGU 2005
*This work funded is by NOAA Office of Global Programs and NASA Tropospheric Chemistry Program
Assimilated Meteorological Data from GEOS:
GEOS-4, 30 -levels 2ox2.5o
GEOS-CHEM Model
May-August 2004 NA Fire Inventory [Turquety et. al, 2005]
EPA National Emissions Inventory 1999 v.1 (w/ modifications to VOCs)
GEOS-CHEM3D Model of Tropospheric
(Ox-NOx-VOC coupled to aerosol) Chemistry
NOx Lightning Emissions [Price and Rind, 1992]
GEOS-CHEM VS. ICARTTMean comparison along the flight tracks
DC-8 (top)
Large UT NO2 bias
BL bias in CO and NO2
Ozone FT bias 5-10 ppbv
Observed Simulated
WP-3 (bottom)
CO NO2 PAN HNO3 O3
Large overestimate powerplant/industry dominated Midwest and in the South
Observed Simulated Improved Simulation
DC-8 Midwest
50% reduction in power and industry source as determined by Frost et al., [2005] improves boundary layer NOx simulation
ICARTT OBSERVATIONS CONFIRM LARGE DECREASE SINCE 1999 IN INDUSTRY/POWER SOURCE
0 1 2 3 > 4
MEAN(Model NOx/ Observed NOx): All DC-8 & WP-3 flts 0-2 km
PAN BIAS: BACKGROUND or N. AMER. ENHANCEMENT?CO – PAN correlations at 8-10 km
Modeled
Observed
PAN discrepancy in enhancement
CO vs. PAN
Asian Fossil Fuel CO tracer vs. PAN
PAN (ppbv)
North American Fossil Fuel tracer vs. PAN
PAN ( ppbv )
PAN correlation dominated by NA tracer
INSUFFICIENT CONVECTIVE INJECTION OF BL POLLUTION? …not likely NOx concentrations
are higher in the UT than in the BL
DC-8 NOx
Observed DC-8 NOx > 8km
National Lightning Detection Network
[Gtons N July 1 –August 15, 2004]
[ppbv NOx]
HIGH UPPER TROP NOx CO-LOCATED WITH LIGHTNING ACTIVITY DURING ICARTT
GEOS-CHEM UPDATED LIGHTNING EMISSIONS vs. NATIONAL LIGHTNING DETECTION NETWORK
GEOS-Chem
Standard Ltng Simulation X 4 over U.S.
National Lightning Detection Network
[Gtons N July 1 –August 15, 2004]
New
OZONE COMPARISON INTEX-NA SOUTHEAST U.S. Lightning increase over the U.S. corrects ozone bias
Improved ozone at surface reflects NOx emission reduction
NO2O3
New
Old
Obs
HOx COMPARISON INTEX-NA SOUTHEAST U.S. 2-3 X bias in upper tropospheric OH
HO2 OH
DECREASING OH WOULD PUT MANY THINGS INTO PLACE… ….but how do you decrease OH by X2-3?
- Reducing OH would allow us to increase lightning emissions by less, thus reducing HNO3
- NOx lifetime would increase, thus fixing underestimate of NOx in upper tropospheric outflow