Search Results

You are looking at 1 - 3 of 3 items for

  • Author or Editor: Howard A. Friedman x
  • Refine by Access: Content accessible to me x
Clear All Modify Search
Jerome Spar
,
Howard A. Friedman
, and
Fred L. Zuckerberg

During the 1966–67 and 1967–68 winter seasons, the ESSA Research Flight Facility carried out several weather reconnaissance missions in east coastal cyclones as part of a project on snow prediction in the northeastern United States. The operation of the aircraft program and the meteorological observations of primary interest are described. The aircraft reconnaissance system is found to be of significant potential value to east coast weather forecasters.

Full access
Howard A. Friedman
,
Gerald Conrad
, and
James D. McFadden

Specially instrumented aircraft of the Environmental Science Services Administration (ESSA), Research Flight Facility (RFF) have supported environmental research efforts for more than a decade. In 1969 the RFF participated in the Barbados Oceanographic and Meteorological Experiment (BOMEX) providing, in addition to approximately 1000 flight hours during the field operating periods of the program (May through July), flights designed to develop operational patterns, test, calibrate and compare sensor derived data.

While the three participating RFF research aircraft accomplished 146 missions, for a total of approximately 1138 hours of flying time, they collected about three million digitally recorded meteorological observations, numerous sea-surface temperature and water vapor flux measurements, two million cloud and radar photographs, and other special data.

A brief description of the scientific objectives of the program, aircraft and instrumentation systems employed, sample tracks, data collected and subsequent procedures are presented.

Full access
Joanne Simpson
,
William L. Woodley
,
Howard A. Friedman
,
Thomas W. Slusher
,
R. S. Scheffee
, and
Roger L. Steele

Abstract

The development, testing and use of an airborne pyrotechnic cloud seeding system is described. Pyrotechnic flares producing 50 gm of silver iodide smoke each were developed by two industrial corporations and laboratory tested for nucleation effectiveness in the Colorado State University cloud chamber. A delivery rack and firing system were developed, under ESSA supervision, and installed on its B-57 jet aircraft. Night flight tests were made of reliability, burn time and flare trajectory.

The flare system was used in a Florida cumulus seeding experiment in May 1968 conducted jointly by ESSA and the Naval Research Laboratory, with the participation of the U.S. Air Force, the University of Miami Radar Laboratory, and Meteorology Research, Inc. A randomized seeding scheme was used on 19 supercooled cumuli, of which 14 were seeded and 5 were studied identically as controls. Of the 14 seeded clouds, 13 grew explosively. Seeded clouds grew 11,400 ft higher than the controls, with the difference significant at better than the 0.5% level. Rainfall from seeded and control clouds was compared by means of calibrated ground radars. Large increases in rainfall were found from seeded clouds, but at a significance level ranging from 5–20% depending on the statistical test used. A single successful repeat of the experiment could result in rainfall differences significant at the 3% level with the most stringent test.

Full access