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- Author or Editor: Otto W. Thiele x
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Abstract
Seasonal and latitudinal variability of density between 30 and 68 km is presented. These data have been derived from direct temperature and height measurements made with meteorological rockets fired at White Sands Missile Range, N. Mex., and Fort Churchill, Canada, during 1960–1962 Meteorological Rocket Network and associated research and development activities. Some of the more significant features are the wider seasonal range at northern latitudes, the absence of significant latitudinal variation during the summer, the greatest variation in the fall and winter at northern latitudes and the overall variation that is indicated in the general region of 50 to 60 kin, as much as 50 per cent in some cases. The need for both seasonal and latitudinal standard atmospheres where standards are required is clearly demonstrated. Also, the feasibility of providing timely density measurements for direct application is evident.
Abstract
Seasonal and latitudinal variability of density between 30 and 68 km is presented. These data have been derived from direct temperature and height measurements made with meteorological rockets fired at White Sands Missile Range, N. Mex., and Fort Churchill, Canada, during 1960–1962 Meteorological Rocket Network and associated research and development activities. Some of the more significant features are the wider seasonal range at northern latitudes, the absence of significant latitudinal variation during the summer, the greatest variation in the fall and winter at northern latitudes and the overall variation that is indicated in the general region of 50 to 60 kin, as much as 50 per cent in some cases. The need for both seasonal and latitudinal standard atmospheres where standards are required is clearly demonstrated. Also, the feasibility of providing timely density measurements for direct application is evident.
Abstract
Two recent series of meteorological rocket measurements in the upper stratosphere and lower mesosphere conducted in the summer and fall of 1965 at White Sands Missile Range, New Mexico, indicate a significant diurnal oscillation of pressure and density in this region. The amplitude of observed pressure oscillations over an averaged layer from 52 to 58 km varied from 4–7 per cent with a mean value of 5 per cent, while the amplitude of density averaged through the same layer varied from 3–5 per cent with a mean of 3.5 per cent. Harmonic analyses of the heights of the 1.0-, 0.6- and 0.4-mb surfaces indicate maxima. at approximately 1400 and 1200 hours (local time) for the summer and fall series, respectively. In the vicinity of 55 km the total range of the diurnal oscillations of pressure and density as evidenced by these data was found to he almost as large as the seasonal variability.
Abstract
Two recent series of meteorological rocket measurements in the upper stratosphere and lower mesosphere conducted in the summer and fall of 1965 at White Sands Missile Range, New Mexico, indicate a significant diurnal oscillation of pressure and density in this region. The amplitude of observed pressure oscillations over an averaged layer from 52 to 58 km varied from 4–7 per cent with a mean value of 5 per cent, while the amplitude of density averaged through the same layer varied from 3–5 per cent with a mean of 3.5 per cent. Harmonic analyses of the heights of the 1.0-, 0.6- and 0.4-mb surfaces indicate maxima. at approximately 1400 and 1200 hours (local time) for the summer and fall series, respectively. In the vicinity of 55 km the total range of the diurnal oscillations of pressure and density as evidenced by these data was found to he almost as large as the seasonal variability.
Abstract
Recent studies of meteorological rocket data have shown a significant diurnal variation of temperature, pressure and density in the stratopause region; however, some doubts have been expressed concerning possible effects on the head thermistor sensing system which may contribute to the large diurnal changes previously observed. While all known effects have been accounted for and no evidence to the contrary has been offered, it seemed worthwhile to investigate this possibility with an independent system which would not be subject to the external effects encountered by the exposed bead thermistor as employed with standard rocketsondes. Consequently, two pressure soundings between approximately 30 and 60 km were obtained with thermal conductivity gages which were incorporated with standard rocketsondes. The thermal conductivity gages were found to be very efficient and reliable in the low subsonic regime encountered with parachute-suspended sounding systems, and good agreement was obtained between the computed and measured pressure and also between the computed and measured temperature.
Abstract
Recent studies of meteorological rocket data have shown a significant diurnal variation of temperature, pressure and density in the stratopause region; however, some doubts have been expressed concerning possible effects on the head thermistor sensing system which may contribute to the large diurnal changes previously observed. While all known effects have been accounted for and no evidence to the contrary has been offered, it seemed worthwhile to investigate this possibility with an independent system which would not be subject to the external effects encountered by the exposed bead thermistor as employed with standard rocketsondes. Consequently, two pressure soundings between approximately 30 and 60 km were obtained with thermal conductivity gages which were incorporated with standard rocketsondes. The thermal conductivity gages were found to be very efficient and reliable in the low subsonic regime encountered with parachute-suspended sounding systems, and good agreement was obtained between the computed and measured pressure and also between the computed and measured temperature.
Radar rainfall measurements over the equatorial western Pacific warm pool were collected by two shipboard Doppler radars as part of the Tropical Oceans Global Atmosphere Coupled Ocean–Atmosphere Response Experiment during the intensive observing period (November 1992–February 1993). A comprehensive dataset of gridded rainfall fields, convective/stratiform identification maps, and vertical structure products has been produced, covering an area approximately 400 km (E–W) by 300 km (N–S) within the Intensive Flux Array (IFA), centered near 2°S, 156°E. The radar rainfall product, which was used as validation for the Third Algorithm Intercomparison Project of the Global Precipitation Climatology Project, indicates an overall average of 4.8 mm day−1; however, correction for range dependence increases the total to 5.4 mm day−1. Rainfall patterns varied considerably during the experiment with isolated convection dominating periods of light winds, while squall lines and organized mesoscale systems were abundant during two westerly wind bursts. An area-average rainfall of 9.9 mm day−1 was observed during the active 2-week period at the end of December, while 0.4 mm day−1 was observed during the quiescent week of 2–8 February. The eastern portion of the IFA received the most rainfall with localized maxima exceeding 16 mm day−1 for the most active 3-week period. Comparison of daily radar rainfall totals with those observed by an optical rain gauge (ORG) on the 2°S, 156°E buoy shows ORG totals to be systematically higher, by a factor of 2.5. The discrepancy results from a higher average rainfall rate, when raining, as reported by the buoy ORG. However, rainfall rate statistics from the ORGs on the research vessel Xiang Yang Hong #5 and from its radar are in excellent agreement under the following conditions: 1) the ship is drifting, and 2) the radar data are in the near vicinity of the ship (3–7 km).
Radar rainfall measurements over the equatorial western Pacific warm pool were collected by two shipboard Doppler radars as part of the Tropical Oceans Global Atmosphere Coupled Ocean–Atmosphere Response Experiment during the intensive observing period (November 1992–February 1993). A comprehensive dataset of gridded rainfall fields, convective/stratiform identification maps, and vertical structure products has been produced, covering an area approximately 400 km (E–W) by 300 km (N–S) within the Intensive Flux Array (IFA), centered near 2°S, 156°E. The radar rainfall product, which was used as validation for the Third Algorithm Intercomparison Project of the Global Precipitation Climatology Project, indicates an overall average of 4.8 mm day−1; however, correction for range dependence increases the total to 5.4 mm day−1. Rainfall patterns varied considerably during the experiment with isolated convection dominating periods of light winds, while squall lines and organized mesoscale systems were abundant during two westerly wind bursts. An area-average rainfall of 9.9 mm day−1 was observed during the active 2-week period at the end of December, while 0.4 mm day−1 was observed during the quiescent week of 2–8 February. The eastern portion of the IFA received the most rainfall with localized maxima exceeding 16 mm day−1 for the most active 3-week period. Comparison of daily radar rainfall totals with those observed by an optical rain gauge (ORG) on the 2°S, 156°E buoy shows ORG totals to be systematically higher, by a factor of 2.5. The discrepancy results from a higher average rainfall rate, when raining, as reported by the buoy ORG. However, rainfall rate statistics from the ORGs on the research vessel Xiang Yang Hong #5 and from its radar are in excellent agreement under the following conditions: 1) the ship is drifting, and 2) the radar data are in the near vicinity of the ship (3–7 km).
