APPENDIX "Dp" PROGRAM 4.0 ~ CLOUD PHYSICS AND METEOROLOGY 1. GLOUD PHYSICS a, ‘This portion of the program was undertaken in order to fully document atomic clouds during their rise in order to obtain information of use in operational air drops, and to allow studies of entrainment of air, turbulence, and diffusion to ‘be made. In addition, it was desired to determine in some detail the temperature and water vapor content of atomic clouds in order to evaluate the possibility of producing artificially stimulated precipitation, 2b. Photographic documentation of the rising atomic clouds was carried on both from the ground and the air for DOG, EASY and GEORGR shots. On DOG shot, the — ground cameras failed to obtain a record due to a low overcast, but adequate cover- age was obtained from the air. Satisfactory ground and air coverage was obtained on both EASY and GEORGE shots and these films are now being processed, Rough analy- sis of data taken by ground observers, using theodolites, on GEORGE shot showed that the third shot attained an altitude of 26,200 feet in 1 minute and 45 seconds, an altitude of 47,500 feet in 3 minutes and 33 seconds, and a final altitude of 70 ,000 feet in 1l minutes and 4 seconds, The radius of the cloud at26,200 feet was 1.2 miles, at 56,500 feet was 3,2 miles, and at 70,000 feet was 5.0 miles. Tb is inter. esting to note that the bomb cloud requires from 11 minutes to 12 minutes to reach maximum altitude regardless of yield. It is also interesting to note that GEORGE shot was the first cloud to actually penetrate the tropopause, c. In order to study the temperature and water vapor content of the atomic cloud, the K@llsman Instrument Company developed a new acrograph which was capable of operation in drone aircraft on a fully aulomatic basis. A total, of thirty aerograph flights were made in and around atomic clouds arising from the three shots. d. Preliminary analysis of a portion of the flights reveals no striking temperature or humidity features in the atomic cloud as compared to ordinary clouds, The temperatures as indicated by the aerograph were lower inside the cloud than in the environment. This apparent whether it is real. anomaly is being investigated further to determine Study of the indicated air speed at the time of entrance into the cloud revealed that in the majority of the traverses a sudden increase in the air speed was experienced although the power, controls, surfaces, etc. remained at constant settings, @. :The humidity traces revealed rather low humidities in the atomic cloud,