INTRODUCTORY REMARKS GTE/PEM-Tropics B FINAL CHEMICAL AND METEOROLOGICAL DATA

This section provides a compendium of NASA DC-8 and P-3B aircraft final data that are available from NASA's Global Tropospheric Experiment's (GTE) Pacific Exploratory Mission-Tropics B (PEM-Tropics B) conducted in March through April 1999.  The format of this product utilizes data plots-time series of selected data acquired aboard the NASA Dryden Flight Research Center's DC-8 and the NASA Wallops Flight Facility P-3B.  The purpose of this product is to provide a representation of the aircraft final data available in archived format via NASA Langley's GTE [anonymous ftp] Data Archive.  The data herein is not intended to support original research or analyses, but to assist in identifying data that are of interest.  The GTE Data Archive and subsequently the Langley Atmospheric Science Data Center, also include numerous supporting data including meteorological observations/products, satellite observations, model studies and data from sonde releases.

Abscissa time scales for a given flight are identical.  Ordinate scales for most flight and species are selected by the plotting software.  In a few cases, however, ordinate scales are selected manually to best represent that data measured for a specie during the flight; some data may be off-scale.  In such a case, the max or min of the data clipped are provided.  As a result of the software used for the plots and the data archive use of codes (in place of valid data) for data taken (1) during instrument calibration, (2) when measurements were at "detection limit" and/or (3) when measurements are invalid, it is sometimes difficult to distinguish  from the plots if data are off-scale or have been coded as invalid.  For example, a symbol without an attached line may either mean that adjacent data are off-scale or have been coded as invalid.  Inspection of the other plotted data often provides information which may resolve the uncertainty.  

In order to maintain the standardized format, plots for flights in which a specie data are not currently available are plotted with the axes and a "NO DATA" entry.   Please note that the label "NO DATA" is used whether final data  (1) is just not available and may be available later or (2) may never be available for that particular flight.  A parameter was not selected for plotting is it was known that it would never be available for any flight.

GMT time has been plotted with a continuous numerical scale beyond 24 hours to conform to the available plotting routine.  GMT midnight is always 24 hours.   

Additional supporting data products available from the GTE Data Archive include:

• PEM-Tropics B Expedition Plan - An overview of the scientific objectives, experiment design, and data management plan for the field experiment.
• Videotapes from each flight - Forward-looking and nadir view videotapes are available from both the DC-8 and the P-3B aircraft. Tapes with quad images are also available for the DC-8 (forward, nadir, quad, stormscope) and the P-3B (forward and quad).
• Ozonesonde data - Correlative measurements from the following sites are available from pre-expedition through winter 1999 at a rate of once per week. Fiji, New Zealand, American Samoa, and Tahiti.

This is a product of the Langley GTE Data Archive Office.  Inquiries about products available from the GTE Data Archive should be addressed to:

NASA GTE Data Manager
Mail Stop 483
NASA Langley Research Center
Hampton, VA 23681-2199

ATTN: Clyde Brown
Phone: (757) 864-5839
Fax:     (757) 864-5841
Email: gte+archive@larc.nasa.gov