HR: 1340h
AN: A23A-0776    [Abstracts]
TI: What PAN Tells us About Continental C & N Outlflow, Airmass Chemical Reactivity, and Appropriate Simulation
AU: * Chatfield, R B
EM: chatfield@clio.arc.nasa.gov
AF: NASA Ames Research Center, MS 245-5, Moffett Field, CA 94035 United States
AU: Binkowski, F
EM: frank_binkowski@unc.edu
AF: Univ. of North Carolina, Chapel Hill, Carolina Env. Prog., 660 B of Amer., Chapel Hill, NC 27599 United States
AU: Duncan, B
EM: duncan@code916.gsfc.nasa.gov
AF: Univ.of Maryland, Baltimore County, Code 916, Goddard Space Flight Center, Greenbelt, MD 20771 United States
AU: Goldan, P
EM: paul.d.goldan@noaa.gov
AF: NOAA Aeronomy Laboratory, R/AL 325Broadway, Boulder, CO 80305 United States
AU: Esswein, R
EM: esswein@clio.arc.nasa.gov
AF: NASA Ames Research Center, MS 245-5, Moffett Field, CA 94035 United States
AU: Esswein, R
EM: esswein@clio.arc.nasa.gov
AF: BAER Institute, MS 245-5 Ames Research Center, Moffett Field, CA 94035 United States
AU: Roberts, J
EM: chatfield@clio.arc.nasa.gov
AF: NOAA Aeronomy Laboratory, R/AL 325Broadway, Boulder, CO 80305 United States
AU: Rodriguez, J
EM: jrodriguez@rsmas.miami.edu
AF: RSMAS, Univ. of Miam, 4600 Rickenbacker Causeway, Miami, FL 33149 United States
AU: Shankar, U
EM: ushankar@email.unc.edu
AF: Univ. of North Carolina, Chapel Hill, Carolina Env. Prog., 660 B of Amer., Chapel Hill, NC 27599 United States
AU: Kuster, W C
EM: william.c.kuster@noaa.gov
AF: NOAA Aeronomy Laboratory, R/AL 325Broadway, Boulder, CO 80305 United States
AB: We compare two recently improved simulations of carbon and nitrogen outflow from North America to a spatially extensive set of airborne observations made in September, 1997, NOAA's North Atlantic Regional Experiment, NARE-97. Peroxyacetyly nitrated, PAN is our central focus. PAN production has strong analogies to pollutant O$_3$ formation in the lower troposphere; it also helps control remote NO$_x$ concentrations. PAN will be analyzed in two ways: (a) as a measure of continuing organic-associated radical activity in distant continental outflow plumes, and (b) as a check on resolution effects in large-scale models. One simulation, NASA's Global Modeling Initiative tropospheric model, currently at 4$^\circ$x4$^\circ$ resolution, will have its first event-simulation tests reported here. The other, the University of North Carolina's research version of the Community Multiscale Air Quality Model, receives here some first tests for very long-distance transport. This model has \sim 1$^\circ$x1$^\circ$ resolution, but is limited to the region from the Rockies to the Central Atlantic Ocean. Since PAN production is proportional to [acetyl peroxy] x [NO$_2$], and each of these factors is expected to decrease rapidly in plumes, PAN provides an incisive analysis tool regarding the effect of resolution and correct meteorology. The competition between reaction and lofting to cooler temperatures is key to PAN concentrations and the global reach of pollutant NO$_x$. An early science result seems signficant: analysis of PAN and the PAN/NO$_2$ ratio in appropriate regions suggest that currently simulated concentrations of CH$_3$CHO seem to be consistent chemically with measured and modeled organics. Current kinetics does appear consistent with than the much higher values of acetaldhyde measured by Hanwant Singh et al. in the Pacific and the Atlantic (but during other missions). We will explore the implications of our comparisons regarding the fate of NO$_x$ and organics, the variable production of O$_3$ in extended continental plumes.
UR: http://geo.arc.nasa.gov/sgg/chatfield/presentations.html
DE: 0345 Pollution--urban and regional (0305)
DE: 0365 Troposphere--composition and chemistry
DE: 0368 Troposphere--constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting