Ionospheric winds measured by gun-launched projectiles

Abstract

Project HARP (High Altitude Research Project) is using gun‐launched projectiles to probe the upper atmosphere. Under this program, 130‐mm projectiles have reached 70 km, and 420‐mm projectiles have been placed 143 km over Barbados. The first experimental program for the 420‐mm gun has been the production of luminous TMA trails for the measurement of winds above 90 km. This smoothbore extended gun is 36 meters long, weights 180 metric tons, and has flown vehicles that generate TMA trails from 90 km to 138 km. In the time period July 1964 to February 1966, forty‐nine such nighttime trails have been photographed and twenty‐nine of these analyzed. During twenty‐two of these flights, concurrent ionosonde records have been taken, and the locations of sporadic‐E layers have been determined for comparison with the wind profiles. The wind data analyzed showed little evidence for the Rosenberg suggestion that the wind vector rotates with increasing altitude. Nine direction reversals occurring in less than 3 km were observed, and fourteen layers of constant direction flow with thicknesses greater than 8 km were observed. A maximum wind speed of 147 m/sec was measured. The six trails of the night of September 20–21, 1965, showed a rapid variation of meridional component of wind at fixed altitude with peak‐to‐peak amplitude of over 200 m/sec. Sine waves were fitted to wind components at fixed altitude with fair‐to‐good standard deviations.

Seasonal variation of ionospheric winds over Barbados, West Indies

“…A minimum of 6 flights a night seems necessary, and 6 such night series have been successfully conducted: September 20- 21, 1965;November 17-18, 1965;November 22-23, 1965;February 23-24, 1966;September 19-20, 1966;and February 15-16, 1967. The data for the first four nights have been completely analyzed and published in this Journal [Murphy et al, 1966;Murphy and Bull, 1967]. In this paper, the re-Copyright ¸ 1969 by the American Geophysical Union.…”

Thermosphere‐Ionosphere Model Development: A Personal Perspective

“…In reality, wind observations in the dynamo region show large height variations, mainly associated with upward propagating atmospheric tides (e.g., Bernard & Spizzichino, 1971;Murphy, 1969;Murphy et al, 1966). Figure 1 shows a picture of the HARP Space Gun, which launched chemiluminescent trails into the lower thermosphere to measure nighttime winds like those in Figure 2.…”

“…The vertical lines show the times of observations. This figure originally appeared asFigure 9ofMurphy et al (1966).…”

gun-launched meteorological probe and its application to a global meteorological sounding network

“…2) that fire subcaliber meteorological projectiles. The bore sizes that have been successfully utilized range from 127 mm (commonly referred to as the five-inch gun) to the 408 mm (16-inch gun), and these guns have placed payloads [11,12] at altitudes in the vicinity of 65 km and 150 km [13], respectively. More meteorological firings have been conducted with the 127-mm gun than any other gun, as it is the lowest in cost and easiest to operate.…”