We examine the sources and chem. affecting nitrogen oxides (NOx=NO+NO2) over the tropical Pacific (30 DegS-20 DegN) using observations from the Pacific Exploratory Mission to the Tropics B (PEM-Tropics B) aircraft mission conducted in Mar.-Apr. 1999. A global model of tropospheric chem. driven by assimilated meteorol. data is used to interpret the observations. Median concns. obsd. over the South Pacific during PEM-Tropics B were 7 pptv NO, 16 pptv peroxyacetyl nitrate, (PAN), and 34 pptv nitric acid (HNO3); the model, generally reproduces these observations but overestimates those over the North Pacific. Lightning was the largest source of these species in the equatorial and South Pacific tropospheric column and in the tropical North Pacific upper troposphere. The oceanic source of acetone implied by high observations of acetone concns., (mean 431 pptv), allows an improved simulation of PAN/NOx chem. However, the high acetaldehyde concns. (mean 78 pptv) measured throughout the troposphere are inconsistent with our understanding of acetaldehyde and PAN chem. Simulated concns. of HNO3 and HNO3/NOx are highly sensitive to the model representation of deep convection and assocd. HNO3 scavenging. Chem. losses of NOx during PEM-Tropics B exceed chem. sources by a factor of 2 in the South Pacific upper troposphere. The chem. imbalance, also apparent in the low obsd. HNO3/NOx ratio, is explained by NOx injection from lightning and by frequent convective overturning which depletes HNO3. The obsd. imbalance was less during the PEM-Tropics A campaign in Sept. 1996, when aged biomass burning effluents over the South Pacific pushed the NOx budget toward chem. steady state.
Copyright 2003 ACS
CAPLUS
AN 2003:348371
59
Air Pollution and Industrial Hygiene
Division of Engineering and Applied Sciences and Department of Earth and Planetary Sciences,Harvard University,Cambridge,MA,USA.
JGRDE3
0148-0227
written in English.
%0 Journal Article
%1 Staudt:2003p949
%A Staudt, A
%A Jacob, D
%A Ravetta, F
%A Logan, J
%A Bachiochi, D
%A Krishnamurti, T
%A Sandholm, S
%A Ridley, B
%A Singh, H
%A Talbot, B
%A Jacob, D
%D 2003
%J Journal of Geophysical Research, Atmospheres
%K imported
%N D2
%P PEM 11/1--PEM 11/17
%T Sources and chemistry of nitrogen oxides over the tropical Pacific
%U /brokenurl#C:%5CDocuments%20and%20Settings%5CGeoffrey%20D.%20Smith%5CMy%20Documents%5CPDF%20Papers%5CJacob%20(PEM-Tropics%20NOx).pdf
%V 108
%X We examine the sources and chem. affecting nitrogen oxides (NOx=NO+NO2) over the tropical Pacific (30 DegS-20 DegN) using observations from the Pacific Exploratory Mission to the Tropics B (PEM-Tropics B) aircraft mission conducted in Mar.-Apr. 1999. A global model of tropospheric chem. driven by assimilated meteorol. data is used to interpret the observations. Median concns. obsd. over the South Pacific during PEM-Tropics B were 7 pptv NO, 16 pptv peroxyacetyl nitrate, (PAN), and 34 pptv nitric acid (HNO3); the model, generally reproduces these observations but overestimates those over the North Pacific. Lightning was the largest source of these species in the equatorial and South Pacific tropospheric column and in the tropical North Pacific upper troposphere. The oceanic source of acetone implied by high observations of acetone concns., (mean 431 pptv), allows an improved simulation of PAN/NOx chem. However, the high acetaldehyde concns. (mean 78 pptv) measured throughout the troposphere are inconsistent with our understanding of acetaldehyde and PAN chem. Simulated concns. of HNO3 and HNO3/NOx are highly sensitive to the model representation of deep convection and assocd. HNO3 scavenging. Chem. losses of NOx during PEM-Tropics B exceed chem. sources by a factor of 2 in the South Pacific upper troposphere. The chem. imbalance, also apparent in the low obsd. HNO3/NOx ratio, is explained by NOx injection from lightning and by frequent convective overturning which depletes HNO3. The obsd. imbalance was less during the PEM-Tropics A campaign in Sept. 1996, when aged biomass burning effluents over the South Pacific pushed the NOx budget toward chem. steady state.
%Z Copyright 2003 ACS
CAPLUS
AN 2003:348371
59
Air Pollution and Industrial Hygiene
Division of Engineering and Applied Sciences and Department of Earth and Planetary Sciences,Harvard University,Cambridge,MA,USA.
JGRDE3
0148-0227
written in English.
@article{Staudt:2003p949,
abstract = {We examine the sources and chem. affecting nitrogen oxides (NOx=NO+NO2) over the tropical Pacific (30 DegS-20 DegN) using observations from the Pacific Exploratory Mission to the Tropics B (PEM-Tropics B) aircraft mission conducted in Mar.-Apr. 1999. A global model of tropospheric chem. driven by assimilated meteorol. data is used to interpret the observations. Median concns. obsd. over the South Pacific during PEM-Tropics B were 7 pptv NO, 16 pptv peroxyacetyl nitrate, (PAN), and 34 pptv nitric acid (HNO3); the model, generally reproduces these observations but overestimates those over the North Pacific. Lightning was the largest source of these species in the equatorial and South Pacific tropospheric column and in the tropical North Pacific upper troposphere. The oceanic source of acetone implied by high observations of acetone concns., (mean 431 pptv), allows an improved simulation of PAN/NOx chem. However, the high acetaldehyde concns. (mean 78 pptv) measured throughout the troposphere are inconsistent with our understanding of acetaldehyde and PAN chem. Simulated concns. of HNO3 and HNO3/NOx are highly sensitive to the model representation of deep convection and assocd. HNO3 scavenging. Chem. losses of NOx during PEM-Tropics B exceed chem. sources by a factor of 2 in the South Pacific upper troposphere. The chem. imbalance, also apparent in the low obsd. HNO3/NOx ratio, is explained by NOx injection from lightning and by frequent convective overturning which depletes HNO3. The obsd. imbalance was less during the PEM-Tropics A campaign in Sept. 1996, when aged biomass burning effluents over the South Pacific pushed the NOx budget toward chem. steady state.},
added-at = {2010-06-22T19:38:37.000+0200},
annote = {Copyright 2003 ACS
CAPLUS
AN 2003:348371
59
Air Pollution and Industrial Hygiene
Division of Engineering and Applied Sciences and Department of Earth and Planetary Sciences,Harvard University,Cambridge,MA,USA.
JGRDE3
0148-0227
written in English.},
author = {Staudt, A and Jacob, D and Ravetta, F and Logan, J and Bachiochi, D and Krishnamurti, T and Sandholm, S and Ridley, B and Singh, H and Talbot, B and Jacob, D},
biburl = {https://www.bibsonomy.org/bibtex/2f7bbd044a0dd58304ee24e89880741dc/gsmith},
date-added = {2010-03-10 16:48:03 -0500},
date-modified = {2010-03-10 16:48:22 -0500},
interhash = {4e250a86ccf3c114eea6ed82a3afea94},
intrahash = {f7bbd044a0dd58304ee24e89880741dc},
journal = {Journal of Geophysical Research, [Atmospheres]},
keywords = {imported},
label = {rec-number 362},
local-url = {file://localhost/Users/geoffreysmith/Documents/Papers/Journal%20of%20Geophysical%20Research%20%5BAtmospheres%5D/2003/Journal%20of%20Geophysical%20Research%20%5BAtmospheres%5D,%20108,%20PEM%20111-PEM%201117%202003.pdf},
number = {D2},
pages = {PEM 11/1--PEM 11/17},
rating = {0},
timestamp = {2010-06-22T19:39:21.000+0200},
title = {Sources and chemistry of nitrogen oxides over the tropical Pacific},
uri = {papers://E88B624E-D406-46FF-9D95-BB9C1AAE3FDC/Paper/p949},
url = {/brokenurl#C:%5CDocuments%20and%20Settings%5CGeoffrey%20D.%20Smith%5CMy%20Documents%5CPDF%20Papers%5CJacob%20(PEM-Tropics%20NOx).pdf},
volume = 108,
year = 2003
}