| Show the airplane Vs the ground generator in cloud seeding explained ff by dr irving P krick krich 0 4 ians darts conquest of the air has rought brought 1 about great changes in our civilization As one of many other developments that have sprung from the invention of the airplane came the original idea of inducing rainfall through artificial nucleation of clouds however increasing field experience in aln id seeding by trained meteor has caused them to abandon aerial projection of silver iodide particles into the atmos atmosphere the airplane is not capable of doing the job that can be achieved with a properly designed ground unit localizing the point of injection 0 silver iodide particles into diio the atmosphere is possible only atrom m a ground generator because f e airplanes dependence upon kis ki v award speed to stay aloft carns s it away from the focal point in nature nucleation of rainfall takes akes place upon particles that are swept into the clouds from the ground the ground generator duplicates this process etli with nuclei of silver iodide which are carried aloft by air currents and the na tural turbulence which always ex 1 ests when conditions for artificial cloud seeding are favorable these particles are so small of an inch in diameter and so liht light li ht that they alise rapidly in a constant flow from the generator to the super cooled cloud where their nu action is possible the ground generator imitates the action of nature in a second way that is impossible when the silver iodide particles are spread evenly and with continuity all through the cloud masses after a long trip from the ground during which they are distributed by moving air masses exactly as in nature the airplane to the contrary introducing its particles P JOE DENNETT joe dennett artist and creator of the comic strip off main street is twenty eight years old and lives in bronx new york joe has been a draftsman movie cameraman and artist for technical animated movies Hs he spent 3 years in the navy two of thern them in m p the south pacific around nl new ev g quinea and the philippines during ve world war 11 II he sold cartos car to leading magazines and since the war has concentrated on his first love comic strips just below or within the doud cloud I 1 forced to concentrate its particles at the point of ejection an and 1 I even distribution of the particles before nucleation is not no possible frequently leads to over seeding and an actual reduction in natural rainfall thus the constant flow of the crystals into the moving air mass made possible by the ground generator makes for their even smooth distribution and the attain ment of bf proper concentrations over wide areas at levels in the clouds where the nuclei do their work the results in uniform rainfall emerging from the super cooled clouds instead of an uneven and irregular pattern which can result in extremely heavy precipitation falling in one restricted ML area a and practically none on immediately adjacent areas thess are important scientific reasons why the airplane has given way to the ground generator in the esteem of the meteorologist trained in the field operations of cloud seeding there are other practical reasons why seeding from planes has proven unsatisfactory for example when conditions are most favorable for seeding they are most hazardous for flying A plane flying through a convective cloud is subject to violent movement and severe icing within the turbulent air mass the type of cloud favorable for seeding is the type that the air line pilots go miles off their courses to avoid when conditions are most satisfactory is for increasing artificial rainfall by artificial nucleation it t is impossible to take advantage of the most favorable opportunities by seeding from airplanes this is especially true in mountainous areas the cloud seeding pilot acknowledges existence of insurmountable danger in the heart of 0 the turbulent cloud by attempting to seed such formations over the top As lids has already been pointed out the silver iodide particles are so light they cannot fall into the cloud within which their presence would increase the volume of rainfall in addition seeding in cooled clouds must start in the lower portions and work up not in the top working down tc achieve increased precipitation the wrong proceed ure can even tend to decrease natural rainfall in some of our seeding work in the pacific northwest our meteor k kept ept their generators operating over a 47 hour period obviously this would have ben bein impossible in an airplane in the area in which we were working there were no navigation aids and the nearest airport was many miles distant under such conditions it would have been immoss ible to put a plane over the area at night whereas the ground generator I 1 kept going without stopping i i for a day and a half |
