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February 1, 1970
� � � � - Approved for Release: 2018/01/30 C00122620 - 1.,�'�41�.�;;-: /a-!�.:�;:..���-;1"� � ��._. �At �-y-toro *.� *e41:74; ����irtk..7 AWs20-- &Tr .ve ',..z70;;E".J;74;�11 - ite3;1%).�W,..1 DIRECTORATE OF SCIENCE /lc TECHNOLOGY � Scientific and Technical Intelligence Report Status and Trendr of the Soviet Weather and Climate Modification Program Mir MI�STIR/70-4 �Febniary 11770 r APR- 1995 r!' Approved for Release: 2018/01730 C00122620 copy N! 292 Approved for Release: 2018/01/30 C00122620 � .;, If APR 1995 APPR'',VFP FASE � Approved for Release: 2018/01/30 C00122620 S � � pproved for Release: 2018/01/30 C00122620 STATUS AND TRENDS OF THE SOVIET WEATHER AND CLIMATE MODIFICATION PROGRAM Prefect Officer OSI-ST1R/70-4 : Fetivory 1970 CENTRAL INTELLIGENCE AGENCY DIRECTORATE OF SCIENCE AND TECHNOLOGY OfRCE Of SCIENTIFIC INTEUJGENCE lir APR 1995 APPROVED FM !iELEASE Approved for Release: 2018/01/30 C00122620 - � KO! �pt.! 'alitftl%::4-ft.;tetdieeZ1/4.�15:!'�''rei4rL :74.1 - %a �.������ � C ; a. . � .1r4110/1/414��- ',taw �Ir pproved for Release: 2018/01/30 -000122620:idallialUe"'"'m PREFACE Weather modification is directed toward changing meteorological phenomena for a short period of time usually over relatively small areas. Climate modification is directed toward changing meteorological phe- nomena over a long period of time usually over a large area. Almost all weather modification techniques can be applied to some type of military operation. Many have significant economic applications. Suc- cessful techniques to increase precipitation or to dissipate severe storms would benefit a country's economy considerably and could also support military operations. Techniques to dissipate or enhance fog and cloud could have important military applications, particularly for tactical op- erations. Even greater military and economic, as well as political, benefit could be derived from a successful method of modifying the climate. This report discusses Soviet progress in weather and climate modifi- cation. �� basic such as cloud �h cs, is also con. side This report, which updates an earlier study on weather and climate modification published in August 1985, has been prepared by the Office of Scientific Intelligence and coordinated twith the Directorate of Intern- "�ence� The cutoff date of infomiation used is October 1999. lir APR 1995 prn!,-,p-rTn rrtrt r, Approved for Release: 2018/01/30 C00122620 � � � PS-3-01S --.4-41-Approved for Release: 2018/01/30 C00122620, e.g. 4. CONTENTS .PREFACE PROBLEM ,1 CONCLUSIONS 1 SUMMARY 2 DISCUSSION 3 Overall weather modification program 3 Hail suppression � 3 Predpitation augmentation 5 Cloud and fog dissipation Severe storm modification 8 Related research 10 Climate modification � UNCLASSIFIED REFERENCES 13 '4 fre p7.;�:7,--.7r11,77,7 ill APR -1995 � - - z Approved for Release: 2018/01/30 C00122620 � IL/eurcy P.Nikalt".741P.: LIAL � Approved for Release: 2018/01/30 C00122620 �I" STATUS AND TRENDS OF THE SOVIET WEATHER AND CLIMATE MODIFICATION PROGRAM . PROBLEM To determine the status and trends of Soviet research and develop- ment in weather and clinsate modification. CONCLUSIONS CONCLUSIONS L The Soviets have maintained a very large weather modification R&D program for a number of years but, despite the size of this program, they have contributed no significant or unique advances to the tmdcrstanding of the phenomena Involved. In cer- tain instances the Soviets have been quicker than the United States to introduce new weather modifi- cation trAniques into operational service. Their climate modification program is still in the con- ceptual or bask research stage as is the case in other countries. 2. The Soviet weather modification program is well organized and apparently has high-level cen- tralized direction. The Soviets have concentrated their MD efforts in sublields they fudge to offer the most premise for military and economic pur- poses. In the 1950s this concentration was on super- cooled fog and clood dissipation techniques, which became operational about 1900. In the 1900s the Soviets concentrated their R&D effortv on hail sup. pression techniques. 3. The Soviets have conducted no known field experiments in climate modification. Conservatism Is e..*.ztated by their inability to predict what effects such experiments might have in geographical areas outside the experimental area. The Soviets are work- ing on mathematical models of the atmosphere to assist them in predicting these effects but their progress has been hindered by the inadequacy of their computers. 4. The concentrated Soviet effort of the past 10 years in hail suppression has progressed to the semi. operational stage and the benefit-to-cost ratio ap- pears to be about 5 to L Some scientific resources used in this developmental effort probably will now be diverted to other weather modification subfields. The most likely subfields for new Soviet R&D ap- pear to be warm fog and cloud modification and/or modification of larger weather systems. Some in. crease in the precipitation augmentation effort also seems possible. & Although most of the Soviet weather modifica- tion program appears to be unclassified, there is e-.4dence of classified R&D in warm cloud and fog modification. Such modification techniques could have Immediate military applications for offensive and defensive tactical operations. rz- APR 1995 AppRrr.r.:1r,- � . 11. E Approved for Release: 2018/01/30 C00122620 Approved for Release: 2018/01/30 C00122620 SUMMARY The major Soviet weather modification effort in the 19503 was on supercooled fog and cloud dis- sipation. This effort culminated in the development of a technique for clearing airports of supercooled fog; a semioperational status was reached in the late 1950s, several years before the Urited States began a similar operational program. After the fog dissipation project passed from the R&D to the operational stage, a large portion of the Soviet scientific resources was diverted to attack- ing the problem of suppressing the number of oecurence. and severity of hailstorms in the USSR. An experimental research area was established in a grape-growing section of the Caucasus in the mid- 19503 and experiments began on a large scale about 1900. The motivation behind this program probably was to a large extent the potential economic bene- fits to agriculture, but a method for dissipating or preventing hailstorms could also have military ap- plications., particularly for protecting vulnerable equipment such as aircraft and missiles. The Soviet hail dissipation experiments have pro- gressed systematically through the past 10 years. Since the Soviets first established the feasibility for modifying hailstorms, they have concentrated on conducting these experiments over different types of terrain, on developing a means for introducing reagents into the clouds, and on improving various related techniques. According to the Soviet theory, the time and place that t1 reagent is introduced Into the cloud is criticaL The use of aircraft was Judged to be inadequate and antiaircraft artillery shells and rockets were developed for this purpose The Soviets claim that their hail suppression re- search program has been ccrmpletey successful. The official Soviet estimate of the benefits versus cad ratio is about 5 to 1 and this estimate probebly is accurate. In 1967 the Soviet government made the decision to expand these operations to all areas of the country subject to significant hail damage, and It now appears that they consider this program to be at least semioperational and no longer expert- mentaL Becanse the Soviets Lave emphasized supercooled fog and cloud dissipation and hail suppression over 2 the past 15 to 20 years, they have put relatively less effort into other subEelds of weather modifica- tion than has the United States. These subEelds in- dude precipitation augmentation and warm fog and cloud dissipation, both of which could have significant economic or military value if techniques are perfected. The Soviets maintain only one known sizeable project (in the Ukraine) engaged in pre- cipitation augmentation, but apparently it has pro- duced no significant amounts of precipitation. Some increased activity in other geographical areas has been noted in the past year. Based on open sources, it appears that Soviet ex- perimental research on warm fog and cloud dissipa- tion is in the initial stage, although there is evidence that at least one classified project was begun a few years ago. One unclassified project is an attempt to prevent fog from forming over the Kola Bay by covering the bay surface with a monomolecular film that reduces the rate of evaporation. A recent in- crease in Soviet basic research on hygroscopic nuclei may indicate that experimental research on warm fog and cloud dissipation using such nuclei win receive greater emphasis. Soviet experimentation on severe storms and modification of large weather systems also is in its beginning stages and the Soviets have no known projects which compare in size or complexity with the US STORMFURY project to modify hurricanes. Current Soviet work on severe storms appears to be confined to experiments on individual cumulus ckuds and thunderstorms. Some success has been reported in -lissipating thunderstorms, but the So- viets need more data to make a final evaluation of the results. No information is available on recent Soviet experiments on large weather systems, but it appears that such work will be stepped up. Soviet scientists and engineers have discussed the possibility of climate modification for many years, particularly the prospects of melting the Arctic ice. The well-known proposal by P. M. Borisov to dam the Bering Strait is directed to this end but Soviet scientists have warned that melting the Arctic ice could have harmful effects on the climate in other areas of the world. The uncertainty of these effects 111111111111111* inr APR 145 APPROvED ZJA re, r .tc .1S� 1/. : .a. ��"lum- 11964i:. � ove,...-,V T"--� -or' - ...:11";tarr',.;r1,11 "�;.; Zi � 'N:j ���1' ;Ale q.. - in ' � &Ain). - stvefiek.44:i....14jur: * � le���� * 4rr � -;,41; "row -.04t,npFT..4". � ..ivvre T.. 44..". � r - Aso - 4411. ?AP. 41:04. Approved for Release: 2018/01/30 C00122620 Approved for Release: 2018/01/30 C00122620 ���� s h. 4- probably has kept field experimentation to a mini- mum. Current basic Soviet research on the develop- ment of realistic mathematical models of the attnce- pbere could greatly assist in predicting effects over the entire Northern Hemisphere. The BESMA probably the best computer available for testing these models, is not adequate for performing the movie: computations frt. olvtd, although even the most advanced computers are not completely ade- quate for this job. The Soviets are actively engaged in research en the microphysics of clouds and precipitation in sup- port of weather modification. They are pat uculariy active in laboratory studies involving cloud chain- hers. They also have been imaginative in applying radar to cloud research and precipitation studies. Soviet administrators of the weather modification program have stated that there is a need for inten- sifying these basic studies. DISCUSSION OVERALL WEATHER MODIFICATION PROGRAM The Soviets have maintained a large weather modification program for about 20 years. In terms of numbers of personnel involved, it probably is the Largest in the world. It appears that the Soviets maintain a much larger field experimental program than the United States but that their related basic research effort is smaller.' Consequently, the Soviets generally have been quicker to test weather modi- fication techaiques in the field than has the United States. The Soviets appear to have a well-organized pro- gram.' High-level direction of the program Is In- dicated by their apparent ability to channel efforts Into particular subfields. Thus very intense work is carried out until a technique is perfected to the point that it can be used operationally or semiopera- dangly. At that time, scientific resources are di- verted to another subfield. M an example, a large Soviet effort in dissipating supercooled fogs and clouds was apparent in the middle and late 1950s. When this technique was developed to the point that tt could be used operationally, the concentra- tion of effort was shifted to hail suppression, where It has been since the early 190. The decision as to which rubfield to concentrate the effort must be made at high levels and probably is based no a combination of factors, such as which areas appear to be the most promising and which have the most military and economic potential It is evident from the published literature that the overall weather modification program in the USSR underwent a considerable expansion in 1990- - by f - � 5- 11-�,v 1984, with a steady but slower growth rate since then.' However, this expansion may have been more apparent than real because a general declassifica- tion of the program in the late 1950s may have re- sulted in an increase in published articles. Never- theless, there is no question that the Soviet weather modification efforts have been increasing and they probably will continue to do so. Further, high-level Soviet officials have indicated that the future pro- gram probably will have a better balance between theoretical research and field experimentation.' Ilan suppression The Soviets have continued to expand their ac- tivities in hail suppression over the past 5 years. This effort, which began in 1956 as a rather small experimental effort in the Caucasus Mountains near Mt. Elbrus, has now expanded to include areas of the republics of Georgia, Moldavia, Tadzhikistan, Ukraine, Armenia and Uzbekistan. Recently a co- operative hail se:pression project has also been ini- tiated with Buizar1a.4 The long time period and the number of r.cperiments conducted probably have given the bevies more experience in this area of weather modification than any other country. The Soviet government made the decision in 1967 to expand the hail suppression operations to include eventually all areas of the USSR that are subject to significant ban damage.' This decision leaves little doubt that Soviet officials are convinced that the method effectively reduces the amount of damaging hall which falls, but there appears to be some ques- tion as to the exact amount that hafi damage is re- duced. G. X. Sulakvelidre, who leads the hail sup- APR 1995 rn TV:1 ro - 3 r7,1v- �r: -? Approved for Release: 2018/01/30 C00122620 Approved for Release: 2018/01/30 C00122620 pression effort in the Caucasus and who is one of the most enthusiastic proponents of the method, claims a benefit-to-cost ratio of about 17 to 1. The official Hydrometeorological Service estimate of the benefit-to-cost ratio appears to be siaout 5 to L' The more conservative estimate probably is closer to the true value. Part of the discrepancy between thete figures probably is due to different methods of figuring the cost of the program. It is not entirely clear bow the cost of such items as guns, rockets, ammunition, and radars are figured into the cost Of the program since some of this equipment appear. to be military surplus material" The benefits of the program are calculated on the basis of insurance claims ;or the protected areas compared with claims for adjacent unprotected areas.* The size of the hail suppression program in the USSR indicates that it has passed from a strictly experimental program into at least a semioperational program It is not likely that the Soviet government would decide to expand a strictly experimental pro- gram into all hail-affected areas of the country. Nevertheless, the fact that a control area is almost invariably established alongside a protected area Indicates that the Soviets do not consider the pro- gram to be entirely operational at present, and they are still interested in obtaining experimental data. The principle behind the Soviet hail suppression efforts is that certain portions of well-developed convective clouds often have large accumulations of moisture in a liquid supercooled state. The ice particles which form as a result of the natural freez- ing of droplets falling through these areas grow rapidly and are transformed into hailstones. The Soviet theory states that by injecting a large num- ber of artifical crystallizaticm nuclei into the cloud, the nuclei can convert the region of high, super- cooled water content into small ice crystals, thereby eliminating the large supply of supercooled water which Is necessary for the formation of hailstones.' According to the Soviet theory, the artificial nuclei must be injected into the portion of the cloud which has the high supercooled water content and they must be placed there before the hailstones can grow to a large size. Soviet observations and computations show that large hailstones can be formed in a matter of 5 to 10 minutes after the hail forming process begins.' 4 The Soviets rely heavily on radar to determine where they want to seed the clouds!' Their experi- ence has shown that the radar reflectivity undergoes a perceptible change in the area of the cloud where the hail formation is beginning. Either rockets or 100-mm antiaircraft artillery are used to deliver the seeding agents to the cloud, and both delivuy sys- tems are tied into radar control points. Based on the military precision with which they operate, the gun crews appear to be either military personnel or civilians who have had extensive training with the guns.' The shells normally are loaded with a lead iodide reagent, and a timing device is used to ex- plode the shell at a preselected point in the tra- jectory. The rockets are equipped with two timing devices: one tp set the time of burning of the reagent and the other to set the time for parachute deployment' Possible danger to the local population from antiaircraft shell fragmenfs or from rockets landing in a populated area does not seem to con- cern the Soviets greatly. They claim that the shells fragment completely and that it is rare to find a piece as large as 1 grain on the ground.' The danger from the rockets is minimized by the use of para- chutes, and the rocket sites are established in rela- tively unpopulated areas. Rocket firings must be coordinated with civil and military aircraft author- ities, who have veto power over rocket firings." There is a certain degree of rivalry between the groups using guns and those using rockets, but there is DO evidence that the Soviet decision makers have any Intention of adopting only one delivery method. The rockets used in the program have undergone continued improvement through the years and the Soviets presently are using a multiple rocket launcher capable of firing four rockets simulta- neously. These rockets are approximately 5 ft long and have a range of about 8 km. The new larger Alazani rocket is now in Its final test phase. It has a launcher capable of simultaneously launching several rockets in different directions.' � Each delivery system has certain advantages and disadvantages. The antiaircraft artillery can deliver a shell to a particular spot in the eoud.with rela- tively good accuracy. When the shall explodes, a large number of nuclei are then released in a rela- tively small volume. A large storm would require a large number of firings to seed it completely. In one operation observed by Western scientists, about 200 rounds were fired to seed one storm.' The rockets 0111111� -Z- Irr APR 1995 r, � ci asELEAsa � Approved for Release: 2018/01/30 C00122620 � - a_aa e .� � ; �ao� r � �2. .1 ri . � . Ap4pro-v-led-Ifor::Rei lea-''Se-:.2-01-8/01/30 CO0122620 � 101111111 apparently also achieve good accuracy and they have the ability to deliver the nuclei over a con- siderable volume of the cloud. The number of nuclei delivered per unit volume is not as high as in the case of the shells, but the rockets are somewhat more versatile in that they can be set to eject the nuclei either in a horizontal trajectory through the cloud or vertically as the rocket descends through the cloud by parachute The hail suppression expedition baited near Kor- meshta in Moldavia appears to be the most sci- entifically oriented group of its kind in the USSR. The Moldavian expedition is under the leadership of I. I. Cayvoronskiy of the Central Aerological Ob- servatory. Although all the hail suppression groups study the result their efforts have on crop damage The largest Soviet weather modification effort to by hail, only the Moldavian expedition apparently increase precipitation is a joint effort between the has made any study of the effects their operations Ukrainian Hydrometeorological Research Institute' have had on precipitation In the area of operations. at Kiev and the Main Ceoplrisical Observatory at Cayvoronskirs statistics, based on 10 years of ob- Leningrad.' This project was established in 1959 servation, tend to show that his operations have had and cloud seeding with dry ice has been carried little effect on precipitation In the area." out continuously since 1259." The Ukrainian ex-. periments have been conducted using two IL-14 aircraft for dispensing dry ice into the clouds. Precipitation augmentation Precipitation augmentation, a subEeld of weather modification popularly referred to as rain-making, has received a large percentage of the total weather modification budget in the United States. In the USSR, however, this subEeld has received consid- erably less effort than that of hall suppression, and there is some indication that it is not receiving un- qualified support at the top administrative levels. One reason may be the belief, expressed by some Soviet crE6cials, that the increase In precipitation produced by cloud seeding has not been great enough to make It economically feasible on a large The overall Soviet hail suppression program is a large, Impressive effort which seems to dominate the entire Soviet weather modification program.' The In setting up this operation, the Soviets estab- Soviets have developed effective delivery systems lished two areas of equal size (3,750 km2) separated and have a well-coordinated program. The primary by a distance of 30 km. All the cloud seeding experi- benefit of hail modification is, as the Soviets have ments have been conducted in the eastern area, stated, for the protection of crops. However, the and the western area has been used as a control area. ability to dissipate hall storms could also be used Operating in this manner, the Soviets are able to by the military to protect personnel and certain avoid contaminating the control area with seeding valuable equipment. The Soviet use of lead iodide nuclei because of the prevailing westerly winds in as a seeding agent may be somewhat less efficient the area. The Soviets set ups dense network of rain than silver iodide, but is not a serious limitation guages In the two areas (one per every 10-12 km2) to the program. to make fine-scale measurement; of natural precipi- tation in the control area and of that from cloud seeding in the operating area. The experimental area Is also instrumented with two radar installa- tions to observe areas of precipitation and to track and control the aircraft doing the seeding." scale.' Another possible explanation is that the So- viets may hnve decided to concentrate their re- sources on hail suppression because the economic benefits were more dear cut Some Soviet scientific resources allotted to hall suppression could be di- verted to other areas of weather modification, such as precipitation augmentation, as the hail suppres- sion operations become less experimental and more operational. In any case, there is little doubt that the Soviets recognize that even a small increase in precipitation at the right time and place can have considerable economic benefits. Military benefits from precipitation augmentation are less clear cut but certain tactical operations could derive some marginal benefits from such a program. The Soviets have seeded stratus and stratocumulus air mass clouds as well as frontal-type clouds in the Ukrainian operaHons. They have reported about a 10 percent increase In precipitation amount: when operating on winter air mass clouds. However, the scientists involved do not consider this a very sig- nificant increase because the total water content of these clouds Is very small in the first place.' They claim to have been more successful when operating 11�11111 iffr APR 1995 Trrs" "r' F 5 r.: aaa rr-1 7:1 Approved for Release: 2018/01/30 C00122620 6.1.11:dliihilApPrOVed -for kelease 2018/01./30 C00122620.... i - MINIP on frontal-typo clouds, with some claiming as much as a 20 to 25 percent increase while others, only about 15 percent.' 12 If this magnitude of precipita- tion augmentation could be achieved for all frontal cloud situations, it could be quite significant. How- ever, the Soviets have determined that only about 50 percent of the winter frontal-type clouds are fa- vorable for seeding." Since 1960 the Ukrainian expedition has also systematically seeded summer cumulus clouds. From 1980 to 1966 the Soviets seeded when possible all clouds which exceed 2.2 km in depth and whose temperature at cloud top was lower than �5� C. 'These parameters had been established, through previous Soviet investigations, as being necessary for favorable seeding conditions. The amount of precipitation which fell over the operational area was then compared with the amount which fell over the control area to determine the effectiveness of the experiments. The results showed some in- crease in the seeded area, but the increase was not large enough to rule out the possibility that it could have been a chance occurrence." Because of this uncertainty in the results, the So- viets changed their approach in 1966 and began the random selection of the clouds to be seeded. The evaluation of these randomized experiments involves the eornparisou of the amount of precipitation from the seeded clouds with the amount from the un- seeded clouds. These experiments have not been under way long enough for them to make a definite conclusion about the effectiveness of the experi- ments; however, preliminary results have not been particularly encouraging." Perhaps the most sig- nificant aspect of these experiments is that this is the first time the Soviets have been known to use this technique. One of the criticisms of the Soviet weather modification experiments in the past has been the lack of statistical controls for evaluation purposes. Randomization is a technique commonly used by Western scientists to establish such con- trols, and recent information indicates that the So- viets will be using it more in the future.". Scientists involved in the Ukrainian experiments have subjected their data to analysis to determine whether or not the cloud seeding operations re- sulted In any decrease In precipitation downwind from the operating area." Several specialists In the field have postulated that such a decrease might 6 occur, but the researchers in the Ukraine turned up no detectable decrease. However, they have reported that a secondary maximum in precipitation down- wind from the operating area seems to be indicated. This secondary maximum, if real, is quite small and probably will have little significance on the overall precipitation pattern producci by the cloud seeding � operations. The only other known sizable Soviet effort to augment precipitation is a project in northern Ka- zakhstan under the control of the Kazakh Scientific and Experimental Hydrometeorological Institute." This effort apparently has been under way since about 1963, but little else is known about it. The Wet that practically nothing has been published concerning this Lffort is unusual; it could indicate that certain aspects of the project are classified, or It might indicate that the operations there are being conducted with little scientific analysis of the re- sults of the experiments. A recent press report has mentioned another operation designed to augment precipitation in the Yakutia ASSR. According to the report, an experiment was conducted to produce rain in the area of a forest fire; however, it is not clear from the report whether this was part of an established weather modification program or was carried out on an ad hoc basis." Cloud and fog dissipation Much of the early effort by the Soviets in weather modification apparently was devoted to the dissipa- tion of supercooled fog and clouds, which has par- ticular application for military and civil air opera- tions. This work proved the feasibility of using cloud seeding techniques. After the feasibility was estab- lished, the major remaining problem was to develop reliable and economical techniques for dispersing the seeding agents. As early as 1959 the Soviets claimed that they were using dry ice on at least a semi-operational basis to dissipate supercooled fogs over airports in the USSR At present the Soviets op- erationally clear supercooled fogs at 10 to 12 airports using ground equipment that blows flakes of CO2 to a height of 20 meters. These flakes are produced from tanks each containing 25 kg of liquid CO3; four tanks are used to seed at 6.5 kg per minute.' In the early 1960s the Soviets reported experiments on clearing large areas (up to 20,000 km*) of super- cooled clou4s. Successful operataions of this type could have considerable military potential for tic- lf APR 145 � � r, Approved for Release: 2018/01/30 C00122620 � � � � � � Approved for Release: 2018/01/30 C00122620 tical air, land, and sea operations, and are of con- siderable scientific interest because the energy in- volved approaches that required to cause a meas- urable perturbation in atmospheric circulation. No seevet referervce has been found to any further op- erations involving large areas, although at a recent meeting, Ye. K. Fedorov, chief of the Main Ad- ministration of the Hydrometeorological Service (CUCMS), stated that more work should be done on large cloud systems" Work still continues in the USSR on supercooled cloud and fog dispersal, but the major effort of Soviet scientists in this subEeld has been diverted to the much more perplexing problem of dissipating warm clouds and fogs.' Warm clouds and fogs are much more prevalent than supercooled types, and they are much less susceptible to modiScatiole The Soviet warm cloud and fog effort is led by the Main Geophysical Observatory in Leningrad with the cooperation of the Central Aerological Observatory In Dolgoprudnaya, the Institute of Experimental Meteorology in Obninsk, and the Ukrainian Sci- entific Research Hydrometeorological Institute In Kiev." Any successful techniques developed in warm cloud and fog dispersal would have consid- erable military, civil, and scientific significance. The Soviet program for modifying warm clouds and fogs generally has proceeded along lines similar to those of Western countries that are active in the field. The major Soviet effort has been devoted to determining the feasibility of using heat sources and of seeding with hygroscopic or surfactant ma- terials.� "The available information indicates that the Soviets have not yet settled on any one tech- nique but that they are still searching for a workable method.� xi Heat sources have been mei et least since World War II when the British developed the fog in- vestigation dispersal operations (FTDO) system to dissipate warm fogs over runways. The prin- ciple behind this method is that the addition of *Hygroscopic materials have the property of increasing the corldemation of water vapor, and such materials is NaCi and Caa. are commonly use.] is hygrosce0c seeding agents. Surfactant materials reduce the surface tension of the cloud or fog droplets, whkli resuN in a more rapid corks- cent rate of the droplets. When the droplets wow la.-ge enough through this room they fan out as rain or mit and the cloud or Fog should dissipate providedthe efficiency 6 greet encash. - beat will result in the evaporation of the fog. The heat may be applied from below, as with the FIDO system, or from above. The addition of beat from above is a commonly observed natural phenomenon when ground fog is dissipated after the sun rises in the morning. In principle, this process can be assisted and speeded up by adding a heat absorb- ing material, such as carbon black, to the top of the fog deck thus increasing the absorption of the solar radiation. The addition of beat to evaporate a warm fog is a proven technique; however, US studies to date have determined that it is only marginally cost effective. Nevertheless, at some lo- cations where fog is very prevalent this method may prove to be worthwhile. The French have made the decision to install Jet aircraft engines underground alongside the runways at Orly Air- field to provide the necessary hest dissipate warm fogs- There is some evidence that the Soviets currently consider the heat source technique to be the most practical, at least for situations where there is a requirement for rapid fog dissieon as might be required for aircraft operations Ilayvoronskly of I' Central Aerological Observatory cites these fige...z from theoretical calculations: for a warm fog 50 m thick with a water content of 0.1 gm/ms, 149 cal/ms of heat are required to disperse the fog in 0.5 minute. To perform the same rate of clearing with hygroscopic' particles, hundreds of kilograms of seedi.ng material per second would be required Ccayvoronslciy further points out that the beating method contributes little pollution to the atmosphere, is fast acting, and is not de- pendent on the varying microphysical characteris- tics of fogs. He concludes from this that thermal methods of warm fog dispersal should be given preference over others." Although there has been some laboratory work reported by the Soviets on hygroscopic and sur- factant materials, there has been surprisingly little repod in the way of actus1fleldepaimenta. Mon. However, one Soviet scientist has stated that Ms laboratory work in this field which for- merly was unclassified has now been classified by the Soviet military." This indicates that the pub- 01111ML . Fr APR 1995. AFTT2::...717, Tut". 7.7.,..�72,S,.. . r I 7 � Approved for Release: 2018/01/30 C00122620 Approved for Release: 2018/01/30 C00122620 bably do not give a true picture a situation, and field experimentakon on the dissipation of warm clouds and fogs very likely is under way in the USSR. The reason such R&D has been classified by the Soviets is not entirely obvious. There is no question that the development of a successful method to dis- sipate warm clouds and fog would have important military implications, but other types of weather modification, which they do not classify, also have such implications. Warm cloud and fog dissipation has the obvious potential for aircraft operations and many ground and sea battle situations. Other reasons for the classification could be that the So- viets have discovered a technique which they be, lieve to be superior to techniques under develop "- merit by other countries or that its potential is greater than other subfields of weather modification. In contrast to the general lack of information on Soviet field experiments on warm cloud and fog dissipation, one field project to disperse fog over Kola Bay has been reported rather freely. This project is under the direction of the Ukranian Scien- tific Research Hydrometeorological Institute, and personnel from Kiev State University and the Mur- mansk Administration of the Hydrometeorological Service also are involved." These experiments were started in the winter of 1964-1965 to determine the feasibility of dispersing warm fogs over the bay by covering the water surface with a monornolecular Elm of higher fatty alcohols. In theory, such a film should reduce the evaporation from the water sur- face thereby cutting off the moisture supply which Is responsible for the formation of the fog. Although the Soviets have claimed some success with this technique, no spectacular results are apparent" One interesting result the Soviets have reported L ow these experiments is that when the winds are stronger than 7 m/sec (about 15 mph) the film is destroyed.' Nevertheless, the Soviets have been successful in ditsipating warm fog using these tech- niques when the proper conditions have existed. HOWeVer, they have found that very large quantities of reagents are needed to clear large areas. Presently they are using kerosene as a solvent for the fatty alcohol reagent, and this presents problem when large quantities are involved. Consequently, the 8 Soviets are stazehing for other solvents which could be used for spreading an effective film on the water." One laboratory experiment has been reported which has interesting possibilities if it proves to be successful. it was an attempt to coat the fog droplets rather than the sea surface with a nsonomolecular film of higher alcohols." If this technique were suc- cessful, it should reduce evaporation within the fog or cloud and thereby prolong rather than reduce the lifetime of the fog or cloud. The capability to prolong cloud or fog lifetime could be used in many tactical military situations, but there are few ob- vious situations where such a technique would have an economic application. This experiment was reported at a 1966 conference in the Soviet Union and no further information has appeared. This could indicate that the Soviets have found the technique to be infeasible under natural conditions as op- posed to the laboratory conditions under which it was first tested with some reported success. On the other hand, it could also indicate that work has continued but has been classified because of military Implications. Severe storm modification The Soviets have scpthted no experiments to modify large severe storms comparable with the US STORMFURY project, which is designed to study the effects of modification techniques on hurricanes. However, the Soviets have conducted numerous experiments on individual cumulus clouds and some on fully developed thunderstorms. These experiments in general have been designed to stop the growth of the cumulus clouds before they reach the thunderstorm stage or, in the case of the experi- ments on cumulonimbus clouds, to reduce the effects after the thunderstorm stage has been reached. In one set of experiments, the Soviets have attempted to produce the opposite effect; that is, to induce the growth of small cumulus clouds into mature cumu- lonimbus clouds. Such experiments, if successful, would have application both for military and civil operations. The ability to prevent severe thunder- storms would be useful for protecting vulnerable military equipment such as aircraft or missiles and for protecting exposed personneL The ability to pro- duce thunderstorms could be used as an offensive weapon In tactical situations. Apii 1995 APPIMED F2977LEISF � � r. � .17:.'-:-' : .!:..: ::-::,. : _ ..44'... 2......0.4174.4-'z....t.' f Approved for Release: 2018/01/30 C00122620 �,, ? .rApproved for 2018/01/30 600T2.26k.f. � N :4,4rA:�; � � � " .1117. =.voai : . �;� -.4' f. .r. � A � � � � A group of scientists under the leadership of the Central Aerological Observatory is conduct- ing an experimental field program in the Geor- gian SSR to dissipate rapidly growing cumulus and cumulonimbus clouds. This project is designed to destory the ascending currents within the cloud and to change them to descending currents. The downward motion 'tops the vertical growth of the cloud and, if it continues long enough, will result eventually in the destruction of the cloud."" In these experiments the Soviets have seeded the grow- ing cumulus clouds with insoluabIe particles of 5 to 50 microns. Different seeding agents have been tested but clay and cement have been the most commonly used. In some of the later experiments a CuO powder also has been tested. The seeding agent is dispensed in fairly large quantities (up to 50 kg have been used) from an IL-29 jet aircraft. The material is ejected into the cloud where upward motion is the greatest; tests have been conducted on clouds of up to 10 Ian in vertical extent." Ac, cording to recent information, the Soviets have con- ducted experiments of this type on 500 cumulus clouds and on 65 cumulonimbus clouds which had reached the durnderstorm stage." The Soviets claim that effects from the seeding were observable on 82 of the CZ experiments on cumulonimbus clouds, and almost all of the cumulus clouds showed an effect." The first effect usually observed after seeding was a noticeable darkening of the cloud followed by lamination and evaporation. Precipitation often was noted falling from the cloud following the seeding, but this usually was very light and in many cues evaporated before reaching the ground. In the majority of CaSel reported, complete dissipation of the cumulus cloud occurred In 20 to 30 minutes, although remnants of middle or high level clouds often persisted." To minimize the possibilities that these effects could have occurred naturally, the Soviets have conducted all the experiments between 1300 and 1000 bra local time when convection normally is at its greatest They also have observed the behavirse of untreated clouds in the vicinity of operations to determine whether any of these dis� sipated naturally. Visual and instrumented observa- tions of the results of these experiments have been carried out from an IL-14 aircraft and by ground- based radars." Apparently no attempt has been made up to the present to randomize the expesi- ments, and it is therefore difficult to judge the true efficacy of the work. However, the results reported are rather impressive and indicate that the Soviets have been able to dissipate at least some cumulus and cumulonimbus clouds under proper conditions. Another project, similar in p.inciple but smaller In magnitude and using different techniques, is being carried out by personnel from the Institute of Experimental Meteorology. This project also is directed toward the dissipation of cumulus clouds by creating artificial downdrafts, but aircraft jets are used instead of cloud seeding agents' Jet air- aaft are flown through the clouds at high pitch angles, thereby directing their Jet dcwrnvard through the cloud. Nine experiments of this type have been reported, and in all cases some effect was noted. According to the Soviet report, the clouds eithtx completely dissipated, broke into paxs, or ceased their vertical growth. The operations were carried out on cumulus clouds ranging from 5 to km in vertical extent" Although positive results were reported from these experiments, the necessity of flying the aircraft through the clouds probably will limit the usefulness of this teclmiqae to a considerable degree. The same experimenters together with personnel from the State Scientific Research Institute of Civil Aviation have tested the feasibility of using jet air- craft engines on the ground to create artificial up- drafts in an attempt to stimulate the growth of cumulus clouds into cumulonimbus clouds. During dry weather in the summer, cumulus clouds often will form but will be prevented from developing Into cumulonimbus clouds by a temperature in- version at some level in the free atmosphere. In theory, if an ascending current could be pcnduced that could penetrate this inversion, the cloud might continue to grow and eventually to produce rain. An analysis of several years' data showed that 75 percent of the summer inversions over Moscow could 'De penetrated in this manner, and in 1967 an experimental apparatus was set up near Borispot Four jet engines were joined so that their exhaust jets all fed into one vertically directed vent Twenty experiments were carried out to test the technique. In most cases the Soviets reported that small cu- mulus clouds were formed over the jets. In the case where natural clouds were already present, they generally became larger in size. In a few cases the clouds darkened at the base and occa- sicmally produced rain. According to Soviet reports, ANEW 40, � � - 1111 APR 1995 , 7,SE 9 "Approved for Release: 2018/01/30 C00122620 ii�-� e - �.. :��� � jt r.�:4,s1 �11 � P. - sr� ��� � - � ����&:- � . �=11LrS *-C:1-4�P:ti�l;%-441114;:r:';5At.. '���-�,":; they plan to continue these experiments and increase the number, of jet engines used from four to ten." These results reported thus far by the Soviets do not appear to be very significant. The use of ad& ticnutl engines might produce better results, but the fuel consumption is likely to make this technique marginal at best with regard to cost effectiveness. However, cost may not be a factor for a military system, and the Soviets might continue MD on this technique if further testing indicates that it may be militarily nsefuL � Related research Despite the relatively large weather modification research effort that has been carried out over a number of years, there are still several questions relating to the basic physics of clouds and precipita- tion that are still not completely understood. One of the unresolved microphysical problems of cloud and precipitation processes concerns the initial stages of rain formation through coalescence of water droplets. A requirement for relatively simple, reliable Ecld instrumentation for measuring the cou- centrations of atmospheric ice nuclei still has to be met. Further, much work needs to be clone on measuring and zprodudng in mathematical models the atmospheric motions in and around clouds." The Soviets have recognized the unsolved prob- lems in basic cloud and precipitation physics, and they have conducted an active research program for many years in these areas. In general, however, It appears that the Soviets lag the United States in these theoretical aspects of their research l The Soviets have acknowledged that they are weaker In the basic research than in the experimental work, and Ye. K. Fedorov In stated that one of his ob- jectives is to strengthen that portion of the program to increase the understanding of the physics of what really happens.2 The Soviets have relied heavily on cloud cham- bers to collect basic data for their microphysical studies on clouds. The Institute of Experimental Meteorology at Ohninsk has at Its disposal three large cloud chambers, two with a volume of 103 ms and one with a volume of 3,200 mi.1" The latter chamber is one of the largest in the world, and one of its advantages is that it *allows larger volumes of clouds to be studied. The 18-rn height of this chamber also allows the Soviets to study the effects 10 of seeding nuclei on the water droplets as the nuclei fall down through the artificial cloud. A distinct disadvantage of the chamber is that the temperature can be regulated only between 15' and 20�C, and the pressure can be regulated only between 3-0 and 1.5 atm." Although these restrictions are not very serious for the study of low-level clouds, they are unreal for higher level clouds. This chamber Is highly instrumented to collect �microphysical data from the artificial clouds contained in it. One impressive instrument used on this chamber is a photoelectric sensor which measures the drop size distribution in the air that is funneled past the counter. This instrument can be set to measure particles in increments of 4-micron steps, the small- est being 2 microns." The two smaller cloud chambers at the Institute of Experimental Meteorology are much more versa- tile than the larger chamber. These cloud chambers are designed so that the temperature can be regu- lated between �50� and 20�C, and the pressure can be regulated from 0.05 to 2.0 atm." Thus these chambers provide for a more nearly real atmosphere than the larger facility and for most research they may be more useful. The Soviets are building a 200 m2 cloud chamber at the Institute of Geophysics under the Georgian Academy of Sciences.� This chamber will have the capability of reaching tem- peratures as low as �40�C but its pressure capa- bility is not known. Preseet plans are to instrumer� this facility with optical lasers and a 1-cm radar to measure the moisture content of the clouds which are produced. It appears that this will be an excel- lent research facility when completed, but ft is somewhat questionable whether the staff at the Institute will be capable of utilizing It to its fullest extentu The Soviet; have also been actively investigating the microphysical properties of clouds using instru- mented aircraft and radar. These types of investiga- tions are necessary to supplement the cloud chamber studies because, no matter how sophisticated a cloud chamber Is, it is impossible to duplicate all the processes and interactions found In the real at- mosphere. Instrumented aircraft, which traditionally have been widely used for collecting microphysical data, are still used, but modern radars are now making it possible to collect much of this data Indirectly. Aircraft measurements suffer from sevetal *1111111* re APR 1995 , :LEASE � � Approved for Release: 2018/01/30 C00122620 � � �.e. � ���� Z. � � 17.a. !I e �2����-s limitations among which are the difficulties in flying through convective-type clouds and problems in developing instruments that will make accurate measurements of the necessary parameters. Soviet development of radars for these purposes generally has kept pace with Western developments. They have done a great deal of work with dual frequency radars: 3- and 10-cm radars are used extensively in the hail suppression program to dis- criminate between hail and nonhail clouds. Informa- tion from the two radars Is fed into one radar con- sole, which then directly presents the difference between the reflectivity of the cloud in the two wavelengths on both the plan position indicator and the A-scope.' The Soviets claim that this differencing technique is very accurate in discrimi- nating between those clouds which produce ban and those which do not They also use the dual fre- quency technique to determine the intensity of pre- cipitation. In this case they use wavelengths of 0.86 and 3.2 an. By measuring the differences in reflec- tivity and absorption In these two wavelengths, the Soviets claim that they are able to overcome the problems of variable drop sizes in the cloud, which make such measurements on single frequency radars difficult." The Soviet capabilities for processing the dual frequency radar information in real time are impressive, and it appears that this technique should be useful for studies of clouds and precipi- tation." The Soviets also use radar methods for other microphysical measurements of clouds, and it appears that their use of radar and radar process- ing equipment for these studies will be expanded.' The Soviets also are actively engaged in seeding- nuclei research. At the present time they seem to favor the use of lead iodide, probably because it is readily available to them."" The United States favors the use of silver iodide over lead iodide be- cause US techniques for crystallization have not worked well with lead iodide. However, ft appears to work satisfactorily with Soviet pyrotechnic methods.* The Soviets have expressed some concern about the toxic effects of lead iodide and they have tested many other substances in the laboratory and some in the field. They seem to favor copper sulfide at the present time to replace lead iodide as the primary seeding nuclei. They claim to have devel- oped a powdered form of copper sulfide that can produce about 1011 nuclei per gram, which is very good. They have also indicated that they have pproved for Release: 26-18/01/3- 5 60-012-26.20 enough confidence in copper sulfide as a seeding nuclei to begin using it in their hail suppression program.' This could be quite significant if success- ful because copper sulfide is a much cheaper prod- uct than silver iodide. Organic materials, hygro- scopic nuclei, and various insoluble materials are also being investigated intensively, particularly for use on nonsupercooled clouds and fogs. CLIMATE MODIFICATION The Soviets have shown an interest in climate modification for many years. This interest probably Is partly due to the unfavorable climate which pre- vails over touch of the USSR. In addition a success- ful climate modification technique could have con- siderable significance for both tactical and strategic military operations.. Many schemes have been pro- posed in the Soviet Union for melting the Arctic ice and thus moderating the average temperatures of the northern areas of the country. One of the oldest and best known proposals is that of P. M. Boriscrn who has advocated &mining the Bering Strait Borisov's concept is to pump water from the Arctic Ocean through a dam into the Pacific Ocean. This, In 'turn, would draw the warmer water from the Atlantic Ocean through the Arctic Ocean and even-. tually melt the ice." Borisov rh;ini that the ice in the Arctic Ocean would be completely melted in three years, and that once melted, it would not return. Borisov, an engineer, claims that this project Is technically feasible, and scientific studies at the Main Geophysical Observatory tend to support his claim that the ice would not re-form once ft was melted. However, M. L Budylco, director of the Main Geophysical Observatory, has pointed out that his studies show that melting the Arctic ice could have adverse effects on the climate of the temperatige zone of the USSR." Despite this warn- ing, Borisov periodically revives his proposal for damming the Bering Strait. Although the Soviets have apparently approached the proposal for large-scale melting of the ice in the Arctic with caution, they have developed and uvol other techniques for melting Ice on a smaller soak. One technique which they have used for many years is to blacken the surface of the ice to increase the amount of solar energy absorbed by the surface. The Soviets *a parently have conclUded that this technique is feasible, although some tech- MN* Er APR 1995 Approved for Release: 2018/01/30 C00122620 11