The Tropical Wind, Energy Conversion, and Reference Level Experiment, or TWERLE, was sponsored by the Goddard Space Flight Center (NASA) and designed and implemented by NCAR and the University of Wisconsin. TWERLE was an intensive program of meteorological observations made from superpressure balloons orbiting the earth at the 150mb density level. The balloons were tracked and monitored by the Nimbus-6 satellite, providing data which increased understanding of atmospheric circulation.
Crew members at three sites in the tropic (Pago Pago in the South Pacific, Ascension Island in the Atlantic, and Ghana in West Africa) each launched about 100 balloons during the summer and early fall of 1975. The launch crews consisted of about five to seven NCAR staffers. A subsequent midlatitude phase, during which balloons were launched from Christchurch, took place from November 1975 to February 1976.
The TWERLE Records include correspondence, budget information, data, reports, publications, and photographs. Files shed light on the design and logistics of the experiment. Selections from this collection are available online.
Arrangement is by original order. This collection consists of 5 series in 3 boxes:
Series 1: Administrative, 1970-1975
Series 2: Correspondence, 1969-1976, undated
Series 3: Research and Data, 1971-1978, undated
Series 4: Presentations, Publications, Reports, 1969-1977
Series 5: Ephemera and Photographs
Physical Access Requirements
The collection must be viewed in the Archives during normal business hours.
This is a legacy collection without documentation regarding the date and manner of acquisition.
Source of Acquisition
Dr. Paul Julian
Method of Acquisition
NCAR Archives legacy collection.
Paul R. Julian Papers
TWERLE [url=https://www.archives.ucar.edu/search/twerle#overlay-context=digital-collections]Digital Collection[/url]
The following publications were removed from the collection as they are available in the NCAR Library:
- TWERLE Flight Test Program Data Summary, December 1972
- Nimbus 6 Data Catalog, Volume 1-11
- Report of Findings: The Effects of Stratospheric Pollution by Aircraft, by A.J. Grobecker, S.C. Coroniti, and R.H. Cannon, Jr.
- Complete 100- and 200- mb GHOST Balloon Data, 1966-1970, NCAR-TN/STR-75, by Samuel B. Solot
This collection was processed in December 2010. Original order was maintained. An unknown person included detailed folder content notes with the records; these notes were copied to the finding aid by the archivist when available. Metal fasteners were removed, acidic sheets buffered, and all materials were rehoused in acid-free folders and boxes.
Tropical Wind, Energy Conversion, and Reference Level Experiment (TWERLE) Records. National Center for Atmospheric Research (NCAR) Archives. https://aspace.archives.ucar.edu/repositories/2/resources/21 Accessed September 18, 2020.