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The Arctic
Outflow Study

Overview and Description
List of the Participants

  
Overview

Levels of photochemically active pollutants are elevated in the remote arctic troposphere during winter and spring, as a result of reduced removal rates and enhanced transport from source regions. Recent work indicates that transport through the Arctic provides a substantial flux of total reactive nitrogen (NOy) and non-methane hydrocarbons (NMHC) to the temperate North Atlantic region. This process may play a significant role in the tropospheric ozone budget of this and other remote regions, thereby affecting concentrations of tropospheric ozone, an important greenhouse gas and photochemical oxidant. However, current understanding of these effects is limited by an absence of measurements of the relevant compounds in southward-transported arctic air.

To provide these necessary measurements, a focused, multi-investigator measurement campaign is proposed. The measurements will take place during January-April 1996 at a site in Newfoundland, within the dominant pathway of springtime arctic air flowing toward the North Atlantic. Measurements will include O3, NO, NO2, peroxyacetic nitric anhydride (PAN), peroxypropionic nitric anhydride (PPN), alkyl nitrates, NOy, C2-C6 hydrocarbons, and CO, plus standard meteorological parameters and Eppley radiometer-based measurement of the NO2 photodissociation rate. Real time isentropic back-trajectory forecasts and meteorological analyses will be used to guide the sampling frequency to ensure adequate coverage during outflow events. Additionally, an archive of back-trajectories ending at the measurements site during the sampling period will be developed to assist data interpretation.

These measurements will provide a clear picture of the seasonal cycle of the observed compounds in outflowing arctic air and of the processes responsible for decay of arctic NOy and NMHC levels during southward flow. Measurements of NOx, PAN, and alkyl nitrates will provide information on the rate of release of NOx from the arctic reservoir compounds PAN and alkyl nitrates. Measurements of NMHCs and alkyl nitrates will provide information on the reaction pathways responsible for alkyl nitrate and NMHC decay and will be used to characterize the importance which halogen reactions--significant sinks for many compounds within the arctic boundary layer following polar sunrise--have on tropospheric composition over a large spatial scale. The results of this study will be used to assess the impact of the winter-spring arctic reservoir on NOy, NOx, and NMHC levels and speciation at lower latitudes. Based on this information and the other species measured, impacts on the local tropospheric ozone formation/destruction rate will be estimated using a photochemical box model, and the resulting impacts on the regional ozone budget will be assessed.

 

Participants

Participant Species or Parameter Method
Richard Honrath, Matt Peterson, and Naresh Badhwar,
Michigan Technological University 		NO, NO2, NOy, Eppley UV, Project oversight O3-Chemiluminescence, Photodissociation/CL, CO-reduction on Au/CL
David Parrish, Matt Warshawsky,
NOAA Aeronomy Laboratory 		CO and O3, Meteorological parameters, Eppley UV UV, NDIR
Dick Norton,
NOAA Aeronomy Laboratory 		HNO3, aerosol-nitrate, aerosol- anions and cations teflon and nylon filter samples
Steve Bertman, Dianna Elyea, and George Nouamie,
Western Michigan University 		PAN, alkyl nitrates GC/ECD
Paul Shepson,
Purdue University 		Alkyl nitrates GC/luminol
Don Hastie and Valerie Young,
York University 		C2-C6 NMHC GC/FID
Jennie Moody,
University of Virgina 		Analysis and summary of real-time meteorological observations, modeling of predicted transport, and forecasts .
John Merrill,
University of Rhode Island 		Forecast and archival back-trajectories .
Participants and Measurements

  
The Cape Norman Site

Height of inlets above surrounding ground: 11.5 m.
Photo of the inlets (missing).

Site Staffing Schedule

Schedule for travel to the site

   
Photos of the Cape Norman Site

Photos of the Lighthouse Measurement Site, its Surroundings, and Maps

Photo of the lighthouse Location of the measurement site and nearby towns in Newfoundland

Photos of the Sampling Equipment

  
Phone Numbers, Addresses, and Travel Information

  
Baron Motel at Cook's Harbour

Researchers at the site are staying at The Baron Motel and Lounge at Cook's Harbour.

  
The Lighthouse

Stephenville Coast Guard has primary responsibility for the lighthouse. St. Anthony Coast Guard can come out for site visits if necessary.

  
Shipments via Interconix

  
Canadian Liquid Air, Ltd.

Compressed gas supplier
Derek McCay (sp), Corner Brook:
Call Derek to order deliveries to St. Anthony of gases already in Cornerbrook.
709-632-5191 (TEL) 709-632-2452 (FAX)

Allan Combdon, St. John's
709-722-5710 (TEL), 709-722-2576 (FAX)

Graham's Auto (St. Anthony depot)
709-454-2065
Delivery schedule: Leave Cornerbrook Monday, arrive St. Anthony Tues, and leave CB Th to arrive SA on Friday.

  
Travel Information

  
PI Phone Numbers

   
Email list of all involved

Email to the following addresses should include all involved:

   
Plots of the Data (restricted access)

Data plots to be added as the data become available.
To submit data or jpg/gif data plot files use ftp. Directions here.

Access to the data plots is restricted to study participants.

Plots of the NMHC mixing ratios from York University are now available.

Single plot of the entire period of available HNO3 data from Dick Norton, showing NOy, NOx, PAN, and HNO3: press here

The following pages show NO, NO2, NOy, and PAN mixing ratios, the fraction of NOy accounted for by these compounds, and give notes on each period of the measurements.

CO, ozone, local met data, and HNO3 etc. from the filter samples will be added as soon as prelimary data are available.

Please do not save links to the web documents listed below; their addresses may change in the future.

Plots are in reverse chronological order - most recent data are listed on the top of this list.

Go to directory containing the gif files for the MTU NOy data plots (this should not be necessary).

  
Exchange of Data Files

Preliminary (and later final) data files will be made available for exchange among project participants.

Format of final data files.

Final data for each of the measurements should be submitted as a pair of ASCII (text) files: a data file and an associated README file.
1.
Data file. Each line of the file will contain the following columns, separated by <TAB> characters:
\begin{figure}\huge \renewcommand{\arraystretch}{1.8}\begin{tabular}{lp{.7\hsi... ...such as uncertainty of the measurement or data flags} \end{tabular}\end{figure}

2.
Readme file. The readme file should contain the following information.
(a)
Point of contact for the data.
(b)
Brief description (with literature citation, if applicable).
(c)
A description of the meaning of the values in each column of the data file, including
  • Meaning of the TIME values in columns 1 and 2 (midpoint of the sampling period or start time). If midpoint, specify the averaging period of the measurements.
  • Identification of the value(s) reported and its units.
  • List and description of any optional parameters included (e.g., end times, additional values such as uncertainty or data flags).
  • Value of the missing data flag, if one is used. (Alternatively, points with missing data may be omitted.)

Data file. Each line of the file will contain the following columns, separated by <TAB> characters:
\begin{figure}\huge \renewcommand{\arraystretch}{1.8}\begin{tabular}{lp{.7\hsi... ...such as uncertainty of the measurement or data flags} \end{tabular}\end{figure}

Readme file. The readme file should contain the following information.

1.
Point of contact for the data.
2.
Brief description (with literature citation, if applicable).
3.
A description of the meaning of the values in each column of the data file, including

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Richard E. Honrath
1999-10-25