Lyatt Jaeglé’s / research
Atmospheric Chemistry Modeling GROUP
 

Long-range transport of pollutants


Regional air pollution has been a significant concern in many parts of the world since the industrial revolution. While industrialized nations have been actively working to improve their air quality by reducing local emissions, many developing countries are now facing growing air pollution problems because of their rapid population and economic growth. Atmospheric transport between continents takes 1-2 weeks on average and, as a result, continental emissions of even short-lived species (lifetimes of weeks to months) can affect the atmosphere above other continents. Thus, in addition to acute local impacts on the source continents, the intercontinental transport of air pollution to receptor regions downwind has far-ranging effects air quality, climate, and visibility.


We have been particularly interested in combining the GEOS-Chem chemical transport model together with satellite, aircraft and ground-based observations to help constrain long-range transport of :

  1. pollution from Asia to the U.S. (Kotchenruther et al., 2001; Jaeglé et al., 2003; Liang et al., 2004, 2005, 2007; Weiss-Penzias et al., 2004; Goldstein et al., 2004; Strode et al., 2008; Fischer et al., 2010; Luan et al., 2012);

  2. pollution and dust from Asia to the Arctic (Di Pierro et al., 2011);

  3. transport and sinks of aerosols over the Arctic (Di Pierro et al., 2013);

  4. biomass burning from Siberia (Bertschi et al., 2004; Jaffe et al., 2004);

  5. dust from the Sahara (McKendry et al., 2007);

  6. biomass burning from Africa (Sinha et al., 2004; Sauvage et al., 2007b).


Aerosol pollutants transported from industrialized regions perturb the radiative balance of the Arctic and affect its ecosystems via deposition on snow, land and water. Our current research focuses on providing improved constraints on the concentrations, distribution, origin and deposition of Arctic aerosols. We use the CALIOP (Cloud Aerosol Lidar with Orthogonal Polarization) instrument onboard the CALIPSO satellite to statistically analyze the vertical, horizontal and seasonal aerosol distribution over the Arctic for 2006-2012. We are interpreting these observations with the GEOS-Chem global tropospheric chemistry model, and use the observations to constrain aerosol sources, removal processes, and transport in the model. We are relating the observed aerosol spatial distribution variability to transport pathways and pollution source regions.


We are also investigating how midlatitude cyclones affect atmospheric composition by vertically redistributing and scavenging trace gases and aerosols. Precipitation in midlatitude cyclones leads to the efficient scavenging of soluble species in the atmosphere. The tropopause folds associated with midlatitude cyclones are preferred locations for irreversible mixing of lower stratospheric air into the troposphere. In recent years, transport within these cyclones has been identified as a major pathway for exporting polluted continental boundary layer air to the free troposphere, thus enabling long-range

transport of radiatively active aerosols, gases and their precursors.


We are generating a multi-sensor composite database of midlatitude cyclones using satellite observations of O3 (MLS, TES, OMI), CO (MOPITT, AIRS, MLS, TES), NO2 (OMI, SCIAMACHY), CO2 (AIRS), aerosols (MODIS, CALIPSO), and H2O (AIRS, MLS). These are complemented by satellite observations of clouds, rainfall, ice water content, and surface wind speed as well as by NASA’s MERRA reanalysis meteorological fields.


Our goal is to address the following objectives: 1) Quantify the spatial distribution of O3, CO, CO2, NO2, H2O, and aerosols within airstreams of midlatitude cyclones using composites of satellite observations; 2) Assess the ability of the GEOS-Chem chemical transport model to reproduce the observed trace gas and aerosol signatures in the satellite composites; 3) Constrain stratosphere-troposphere exchange within midlatitude cyclones; 4) Examine the effect of midlatitude cyclones in exporting polluted boundary layer air to the global atmosphere. The results will be analyzed as a

function of location, season, and storm intensity.


People


Maurizio di Pierro, Graduate Student

Lyatt Jaeglé, Professor


Funding


This work is currently being funded by

> NASA, 2011-2014 Atmospheric Composition: Modeling and Analysis (PI: Lyatt Jaeglé, co-I: Rob Wood)

> NASA, Earth and Space Science Fellowship to Maurizio Di Pierro (PI: Lyatt Jaeglé)


We also gratefully acknowledge past funding from

> NASA, 2007-2011 (PI: Lyatt Jaeglé)

> NOAA, Office of Global Programs, 2001-2003 (PI: Dan Jaffe, co-PI: Lyatt Jaeglé)

>National Parks Service, 2002 (PI: Dan Jaffe, co-PI: Lyatt Jaeglé)

>University of Washington, ADVANCE Transitional support program, 2002-2003 (PI: Lyatt Jaeglé)

>NSF, Faculty Early Career Development (CAREER), ATM-0238520, 2003-2008 (PI: Lyatt Jaeglé).


Publications


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