1. Introduction

This CD-ROM contains the data pertaining to the Stratospheric Photochemistry, Aerosols and Dynamics Expedition (SPADE) which was based at Ames Research Center in California during portions of 1992 and 1993. Most of the data are in essentially final form, however additional calibration work is being done for some of the instruments. None of the instrument data is expected to change significantly from the values reported here. A second edition incorporating updates and/or changes to the data is anticipated in late 1994 or early 1995.

The data consist of measurements collected onboard the NASA ER-2 aircraft, and selected radiosonde soundings from stations in the region of the experiment. Flights were conducted during October and November of 1992, April and May of 1993, and October of 1993.

Theory team products come in two forms -- as quantities evaluated along flight tracks and as global or hemispheric fields. Meteorological quantities, such as temperature, geopotential, and potential vorticity are available in both forms. They are based on analyses from both the U.S. National Meteorological Center and from the Assimilation Model of NASA's Goddard Space Flight Center. Other quantities, available along flight tracks only, include visible reflectivity, cloud height, UV reflectivity, and total ozone. The first two are derived from GOES imagery, the last two from the Meteor TOMS sensor. Finally, calculations of mixing ratios of selected chemical species using a photochemical steady state model are available along the flight track.

All files within this release are standard ASCII files with variable length records terminated by a carriage return/line feed pair (, ASCII decimal values 13 and 10). Therefore, MS-DOS users should be able to read them as they are, but UNIX and Mac users will have to strip off either the or the from each line to convert them to standard UNIX or Mac files. Commercially available software, such as dos2unix and Apple File Exchange, exists to convert MS-DOS files to both UNIX and Mac files. VMS users can define the files to have STREAM record formats.

The file naming convention uses a two-character prefix to identify the measurement, followed by a six digit number (yymmdd) giving the year, month, and day (UT) of the flight, balloon launch, or model result. To identify the measurement platform, a three character extension of EA1, Bhh, or Ghh is used to denote the data is from the ER-2, balloon, or grid point model output (hh denotes the UT hour of balloon launch or model result).

2. Directories

2.1 The DOCUMENT directory contains several files documenting the contents of this edition.


  • 2.1.1 CONTACT.DOC contains an updated list of names, addresses, and phone numbers of the principal investigators responsible for generating the datasets in this release.
  • 2.1.2 ER2TABLE.DOC contains a record of the available ER-2 datasets in tabular format.
  • 2.1.3 FORSPEC1.PS and FORSPEC2.PS are PostScript files of the document entitled "Format Specification for Data Exchange" which defines the standard file formats in which all data are recorded. These two PostScript files can be printed on any printer that understands PostScript. FORSPEC1.PS contains the title page and table of contents; FORSPEC2.PS contains the bulk of the document.
  • 2.1.4 UV_VIS.DOC contains a detailed description of the UV-Vis experiment, also known as the Composition and Photodissociative Flux Measurement (CPFM). Note that the file name contains an underscore, not a hyphen, to conform to the ISO 9660 file naming standards.

2.2 The DATA directory has three subdirectories for the ER-2, model results, and radiosonde soundings data files.



      • 2.2.1 ER2 contains the available data collected onboard the ER-2 aircraft. It also contains several derived quantities. These include (1) "string files" (values along the flight track) and "curtain files" (values in a vertical curtain along the flight track) of potential vorticity, temperature, geopotential, and horizontal wind (derived from analyses of U.S. National Meteorological Center data and the Assimilation Model of NASA's Goddard Space Flight Center); (2) "string files" of underlying visible and UV reflectivity, underlying cloud height, and total ozone; and (3) "string files" of selected species mixing ratios from a photochemical steady state model. Each file contains data for one flight which begins on the UT date indicated by the file name.
      • 2.2.2 MODEL contains 12 Z hemispheric analyses of potential vorticity, temperature, horizontal winds, and geopotential.
      • 2.2.3 RAOB contains selected radiosonde soundings near the aircraft flight tracks. Each file contains one or more soundings for a particular time period.


      1. Directory Structure for this CD-ROM is as follows:
    • README.DOC in top level directory
    • >

    • DATA
    • |-- ER2
    • |-- MODEL
    • |-- RAOB


    This documentation and the accompanying data files were compiled by:

    Steven Gaines
    NASA Ames Research Center
    M/S 245-3
    Moffett Field, CA 94035-1000

    Patti Hathaway
    NASA Ames Research Center
    M/S 245-5
    Moffett Field, CA 94035-1000

    Steve Hipskind
    NASA Ames Research Center
    M/S 245-5
    Moffett Field, CA 94035-1000

    We have left the quality control of the data to the principal investigators and have checked only the format of the data files. Therefore, if problems with the data are encountered, please inform us or the appropriate principal investigator.