Search Results
You are looking at 1 - 2 of 2 items for :
- Author or Editor: Robert A. Mack x
- Monthly Weather Review x
- Refine by Access: All Content x
Abstract
A technique was developed for estimating the condensation rates of convective storms using satellite measurements of cirrus anvil expansion rates and radiosonde measurements of environmental water vapor. Three cases of severe conviction in Oklahoma were studied and a diagnostic model was developed for integrating radiosonde data with satellite data.
Two methods were used to measure the anvil expansion rates–the expansion of isotherm contours on infrared image, and the divergent motions of small brightness anomalies tracked on the visible images. The differences between the two methods were large as the storms developed, but these differences became small in the latter stage of all three storms.
A comparison between the three storms indicated that the available moisture in the lowest levels greatly affected the rain rates of the storms. This was evident from both the measured rain rates of the storms and the condensation rates estimated by the model. The possibility of using this diagnostic model for estimating the intensities of convective storms also is discussed.
Abstract
A technique was developed for estimating the condensation rates of convective storms using satellite measurements of cirrus anvil expansion rates and radiosonde measurements of environmental water vapor. Three cases of severe conviction in Oklahoma were studied and a diagnostic model was developed for integrating radiosonde data with satellite data.
Two methods were used to measure the anvil expansion rates–the expansion of isotherm contours on infrared image, and the divergent motions of small brightness anomalies tracked on the visible images. The differences between the two methods were large as the storms developed, but these differences became small in the latter stage of all three storms.
A comparison between the three storms indicated that the available moisture in the lowest levels greatly affected the rain rates of the storms. This was evident from both the measured rain rates of the storms and the condensation rates estimated by the model. The possibility of using this diagnostic model for estimating the intensities of convective storms also is discussed.
Abstract
GOES stereoscopy is applied to the study of severe squall line cells. Short interval (3 min) GOES stereoscopic data from the 2–3 May 1979 SESAME case were used to measure cloud top heights of growing storms as a function of time. A one-dimensional cloud model was used to relate the stereoscopically derived cloud top ascent rates to thunderstorm updraft intensity. Results show ascent rates ranging from 4.4 to 7.7 m s−1 for intense cells in a squall line. These results compare well in magnitude with growth rates determined from simultaneous GOES infrared observations and previous estimates of visual cloud and radar echo top growth rates of other thunderstorms.
Detailed stereoscopic cloud top height contour maps of the mature squall line on 2–3 May 1979 were constructed and are discussed here in terms of the small-scale structure and its variability. Results show that for small-scale features (e.g., 5 km diameter tropopause penetrating towers) the short-interval GOES data are not sufficient for studying the life cycle of such features. The stereoscopic height contours are compared to infrared cloud top temperature patterns observed with intense thunderstorms and used to evaluate various theories on the cause of the infrared V-shaped signatures.
Abstract
GOES stereoscopy is applied to the study of severe squall line cells. Short interval (3 min) GOES stereoscopic data from the 2–3 May 1979 SESAME case were used to measure cloud top heights of growing storms as a function of time. A one-dimensional cloud model was used to relate the stereoscopically derived cloud top ascent rates to thunderstorm updraft intensity. Results show ascent rates ranging from 4.4 to 7.7 m s−1 for intense cells in a squall line. These results compare well in magnitude with growth rates determined from simultaneous GOES infrared observations and previous estimates of visual cloud and radar echo top growth rates of other thunderstorms.
Detailed stereoscopic cloud top height contour maps of the mature squall line on 2–3 May 1979 were constructed and are discussed here in terms of the small-scale structure and its variability. Results show that for small-scale features (e.g., 5 km diameter tropopause penetrating towers) the short-interval GOES data are not sufficient for studying the life cycle of such features. The stereoscopic height contours are compared to infrared cloud top temperature patterns observed with intense thunderstorms and used to evaluate various theories on the cause of the infrared V-shaped signatures.
