COBRA-NA 2003

• Contact, facility and technical information (all users)
• Figures and Results (all users)
• 18 Aug. 1500 EDT Agenda for the PRESENTATIONS and notes for the electronic science team meeting
• Flight Table (updated as needed)
• COBRA-NA 2003 Photo Album
• COBRA in the News
  
• Forecasting/Meteorological Support
• Data link (authorized users only)
• Data Policy (Provisional)

Citation aircraft (left), flight tracks(right)

COBRA 2003 Program Description

The objective of COBRA 2003 is to test concepts for observations and data assimilation to determine the large scale sources and sinks of greenhouse gases and ozone-destroying gases from North America. The study will cover spatial scales from regional to continental. Gases of interest include CO₂, CO, CH₄, N₂O, chlorofluorcarbons (CFCs), chlorinated solvents (CH₃CCl₃, CCl₄ ), SF₆, ozone (O₃), and molecular hydrogen (H₂).

The capability to measure current and future sources and sinks of greenhouse gases and ozone-destroying chemicals represents a challenging scientific problem with important societal consequences. In order to predict future climate forcing and to project reocovery of stratospheric ozone from current levels of depletion, we must be able to determine the location and magnitude of emissions and understand them. But current models that simulate emissions of greenhouse gases do not represent current observations of concentrations across latitudes or vertical profiles of these gases within a factor of two. Transport of these gases into the middle and upper atmosphere is uncertain because convection, land ocean exchange, and other atmospheric processes are very difficult to model. The thickness of the atmospheric boundary layer decreases from daytime to nighttime, and transport processes also change seasonally. Diurnal and seasonal variations of atmospheric dynamics are correlated with variation of surface emissions, especially for CO₂, making observations of trace gases very difficult to interpret.

Previous studies have pointed out a large terrestrial sink for CO₂ exists in North America. Systematic vertical profile data of the trace gases between 30 and 10,000 meters are required to critically test the models used in these analyses. A series of atmospheric experiments called the CO₂ Budget and Regional Airborne Study with recent emphasis on North America is intended (COBRA-NA 2003) is intended to take first steps in this direction. The experiment is anchored upon the extensive ground-based data from the National Oceanic and Atmospheric Administration/Climate Monitoring and Diagnostics Laboratory (NOAA/CMDL) Cooperative Station Networks for carbon cycle and halocarbon trace gases. The experiment will focus also on the extensive emission data at Harvard Forest, Massachusetts over the past 10 years by flying across the pollution plume from the New York City and Washington, D. C. metropolitan corridor. The intention is to estimate emissions using a data assimilation approach (click to download refs. 1, 2, and 3) as well as by using a carbon monoxide (CO) as a reference for emission strength combined with the trace gas-CO correlations observed in COBRA-2003.

This experiment is a continuation of an earlier COBRA experiment over a more limited region of North America in 2000. In that study significant deficiencies were discovered in the resolution and mass conservation properties of many existing data sets for analyzed meteorological fields. These issues currently limit the capability to accommodate the high degree of variability of local CO₂ emissions (patchiness) and to use the information about sources contained in observed atmospheric variations. The current measurements will be analyzed using the advanced regional-scale meteorological model from scientists at the University of Sao Paulo (Brazil), who will collaborate with the team to apply their BRAMS model (Brazilian development of the Regional Atmospheric Mesoscale Modeling System (RAMS) model) for atmospheric dynamics to address the deficiencies of current meteorological models.

The aircraft platform used in COBRA-NA 2003 is the University of North Dakota Cessna Citation II, a modified executive jet for atmospheric research (see picture above).

The airborne experiment consists of a racetrack from Boulder to the west coast of the United States (Eureka, California) North to Campbell River British Columbia, across Canada to the east coast of North America (Yarmouth, NS), south to Portsmouth, NH, and back to Boulder (see map). Vertical profiles have been acquired over NOAA/CMDL cooperative stations located at Niwot Ridge, Colorado, Moody, Texas, Trinidad Head, and Harvard Forest. Other NOAA/CMDL stations and AmeriFlux and Fluxnet Canada sites along and outside the racetrack will provide important data on the boundary conditions for the flow of air through the area of the racetrack and for surface exchange fluxes. There have also been also excursions over the Pacific Ocean from California, and the Atlantic Ocean from Pease, New Hampshire to Sable Island to examine coastal influence of marine air and the mixing processes between maritime and continental air, and intensive regional flights in Oklahoma and New England. The two bases of operations will be one at the Jefferson County Airport (Jeffco) in Broomfield, Colorado, and the other at Pease (Portsmouth), New Hampshire.

Test flights started on May 22, 2003 at Jeffco Airport and the first racetrack started there on May 26. The second racetrack started from Jeffco on June 19 and until June 28.

Measurements of CO₂, CO, H₂O, aerosol size and concentration will be measured at 1 Hz on the aircraft by scientists from Harvard University and University of North Dakota. Scientists from the Halocarbons and other Atmospheric Trace Species Group (HATS) group in NOAA/CMDL will be operating an in situ gas chromatograph (GC) . The HATS airborne GC, Airborne Chromatograph for Atmospheric Trace Species (ACATS-IV), measures twelve different trace gases including nitrous oxide (N₂O), SF₆, CFC-12 (CCl₂F₂), and halon-1211 (CBrClF₂), once every 75 seconds; and hydrogen (H₂), CO, methane (CH₄), CFC-11 (CCl₃F), CFC-113 (CClF₂-CCl₂F), chloroform (CHCl₃), methyl chloroform (CH₃CCl₃), and carbon tetrachloride (CCl₄) once every 150 seconds.

A whole air sampler (WAS) for flasks will be operated by researchers from the Cooperative Institute for Research in the Environmental Sciences (Univ. of Colorado), the National Center for Atmospheric Research, and Scripps Institution for Oceanography.   The WAS collects air in glass flasks to be measured for a suite of trace gases at Scripps, NOAA/CMDL, and CU/INSTAAR.  These include CO₂, CO, H₂, CH₄, N₂O, and SF₆ concentrations, and ratios of O₂/N₂, Ar/N2, and isotopic C¹³/C¹² and O¹⁸/O¹⁶ in CO₂, and C¹³/C¹² in CH₄.

The program is being coordinated with the Fluxnet Canada Research Network (FCRN) and Environment Canada.  

The project scientist is Professor Steven C. Wofsy of Harvard University. The Terrestrial Ecology Program (director, Dr. Diane E. Wickland) of NASA's Earth Science Enterprise is providing the principal funding for this airborne campaign, with additional resources from NOAA-CMDL and NOAA-OGP, NASA's Upper Atmosphere program, and from NSF (Atmospheric Chemistry Program and NCAR).

 

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• COBRA team contact information
• COBRA Collaborating Scientists in USA and Canada
• Lin Huang proposed flask sampling schedule for Fraserdale Updated 20-June-03 (Excel)
• Trinidad Head updated data and related information:
  Updated data     Data descriptors and Trinidad overview
• Pease facility information
• Directions to Pease Airport
  
• Directions to Jeffco Airport
  

COBRA in the News:

• Environment News Service
  
• National Oceanic and Atmospheric Administration
  
• Rocky Mountain News
• The Daily Camera
• Denver Post
• The COBRA Brotherhood (those who went beyond the call of duty)
  

 
  =======================End flight table=======================

Preliminary Cross Section Figures

• Boulder to Medford, OR [030526ab]

  CO₂   CO   CH₄   O₃   SF₆  

• Medford, OR to Campbell R., B.C. [030528~030529a]

  CO₂   CO   CH₄   O₃   SF₆  

• Campbell R., BC to Mont Joli, PQ  [030529b~030531a]

  CO₂   CO   CH₄   O₃   SF₆  

• Mont Joli, PQ to Boston, MA [030531b]

  CO₂   CO   CH₄   O₃   SF₆  

• Pease-Yarmouth-Bangor [030603a]

• Bangor-Sable-Pease [030603b]

• Pease-Harvard Forest-Pease [030606a]

• Pease-Harvard Forest-Pease [030606b]

• Pease-Baltimore-JeffCo [030611a-030612b]

• CorpusChristi-Palacios-Temple [030614b]

• Jeffco-ARM-Ponca morning [030616a]

• Jeffco-ARM-Ponca afternoon [030616b]

• JeffCo-Eureka-Medford [030618a-030618b]

• Medford-Campbell River [030619a]

• Campbell River-Chibougamau [030619b-030623a]

• Chibougamau-Pease [030623b]

• Pease-Terre Haute-Jeffco [030627a-030628b]

Links

• U.S. Global Change Research Program:  Carbon Cycle Science Program
  
• North American Carbon Program
  
• Harvard University Atmospheric Sciences
  
• NOAA-CMDL
• UND Citation II Aircraft
• NCAR Research Aviation Facility