Intercontinental Chemical Transport Experiment North America (INTEX-NA)

The Intercontinental Chemical Transport Experiment (INTEX-NA) is a NASA-organized atmospheric chemistry field experiment to quantify North American export and import of ozone, aerosols, and long-lived greenhouse gases. Understanding the transport and transformation of gases and aerosols on transcontinental and intercontinental scales is essential for improved air quality and climate research.

A particular focus of this study is to quantify and characterize the inflow and outflow of pollution over North America. INTEX-NA will also provide important validation of satellite observations with ongoing satellite measurement programs, such as Terra, Aura, and Envisat. The experiment will be supported by forecasts from meteorological and chemical models, surface and satellite observations, and ozone probe releases.

The INTEX-NA campaign will be greatly enhanced by a number of concurrent national and international field campaigns. The National Oceanic and Atmospheric Administration (NOAA) is the principal U.S. partner for NASA and will field coordinate airborne and shipboard platforms. Investigation of the transatlantic transport of ozone and aerosol pollution will be done in partnership with European aircraft missions, involving groups from the U.K. (ITOP), France (CNES), and Germany. Synthesis of the combined observations from surface, airborne, and space platforms will maximize scientific results and should directly benefit scientific understanding of air quality and its relation to climate change.

The principal NASA platform for INTEX-NA is the DC-8 with long-range and high-altitude capability, providing a comprehensive suite of chemical, physical, and optical measurements involving gases and aerosols. Complementing the NASA DC-8 will be up to 12 other aircraft operating over North America and the Atlantic.

The INTEX-NA observational database will be obtained in two intensive airborne missions. Phase A will be performed in summer 2004, when photochemistry is most intense and climatic issues involving aerosols and the carbon cycle are most significant. Phase B will take place in spring 2006 when Asian transport to North America is at its peak. The two phases of INTEX-NA will allow investigation of the seasonal variation in the surface fluxes of important biogenic species such as carbon dioxide and oxygenated organic compounds.

A number of previous aircraft missions (NARE, ITCT-2K2, ABLE-3, SOS, and others) have provided important information on continental boundary layer chemistry and North American outflow. INTEX-NA will be able to sample both the continental boundary layer and the North American outflow, providing a range of constraints. It will benefit from a greater range of satellite coverage than available for previous missions.

INTEX-NA is sponsored by the NASA Office of Earth Science Tropospheric Chemistry Program.

Contacts:

Jim Gleason
Program Manager
Headquarters, Washington DC
James.F.Gleason@nasa.gov

Michael Craig
Project Manager
Ames Research Center
Michael.S.Craig@nasa.gov

Science Goals:

• Provide the observational database needed to quantify the inflow and outflow of greenhouse gases and aerosols over North America.
• Quantify the outflow of chemically important trace gases and aerosols from North America to the Atlantic, and relate this outflow to our understanding of sources and sinks over North America.
• Understand the transport and chemical evolution of the North American outflow over the Atlantic.
• Assess the impact and implications of the intercontinental transport of pollution on the global atmosphere and on regional air quality and climate.
• Validate key satellite observations of gases in the troposphere, especially from Aura and Envisat.
• Characterize air masses entering the United States from its western, southern, and northern boundaries; and compare measured chemical fields with those forecasted by regional and global models.
• Quantify the transpacific transport of Asian pollution to North America and its implications for air quality (phase B).

Partners:

NASA researchers will work in close collaboration with scientists from the following:

• NOAA Aeronomy Laboratory
• International Consortium for Atmospheric Research on Transport and Transformation (ICARTT)
• Intercontinental Transport and Chemical Transformation of Anthropogenic Pollution (ITCT) program
• New England Atmospheric Investigation, Regional Modeling, Analysis and Prediction (AIRMAP) program
• Harvard University Atmospheric Chemistry Modeling Group
• Several European aircraft missions

When:

May 25 August 19, 2004 (with Phase B to completed during spring 2006)

Where:

The experiment will be conducted over the continental United States during the summer of 2004 using a variety of science aircraft. Several coastal and continental sites across North America have been selected as bases of operation. The NASA DC-8 will be operated from bases in California, Illinois, Missouri, and New Hampshire. Flights will pursue targeted objectives with optimized observational priorities.

Links:

NASA's INTEX-NA Campaign Site:

http://cloud1.arc.nasa.gov/intex-na/

NASAs Earth Science Enterprise:

http://www.earth.nasa.gov/

NASAs Atmospheric Sciences Data Center:

http://eosweb.larc.nasa.gov

NASAs Sunphotometer/Satellite Team:

http://geo.arc.nasa.gov/sgg/INTEX/

NOAA Aeronomy Laboratory:

http://www.al.noaa.gov/

New England Air Quality Study:

http://www.al.noaa.gov/2004/

International Consortium for Atmospheric Research on Transport and Transformation (ICARTT):

http://www.al.noaa.gov/ICARTT/

Intercontinental Transport and Chemical Transformation of Anthropogenic Pollution (ITCT) program:

http://www.al.noaa.gov/ITCT/

New England Atmospheric Investigation, Regional Modeling, Analysis and Prediction (AIRMAP) program:

http://airmap.unh.edu/home/index.cfm

Harvard University Atmospheric Chemistry Modeling Group:

http://www-as.harvard.edu/chemistry/trop/intex+itct2k4/