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NASA TECHNICAL TRANSLATION NASA TT P-15,687 



THE INITIAL PHASE OF A TROPICAL CYCLONE PROM 
"SOYUZ-9" SPACECRAFT PICTURES 

v. A. Bugayev, A. G. Nlkolayev, T. P. Popova 
and V. I. Sevast'yanov 



{NASA-TT-F-15687) ' THE INITIAL PRASE OF 
A TROPICAL CYClONii FHOH SOYUZ-9 



N7a-29101 



^ 



SPACECRAFT PICTURES (Scientific ^^^^^^ 
Translation Service) 9 p BC $4.00 ^^^^ ^^^ ^^^^^ ^^^^ J 



Translation of "Nachal'naya faza tropicheskogo 
tslklona po snlmku s kosmicheskogo korablya 
Soyuz-9". Meteorologlya 1 gldrologiya. 
No. 4, 1974, Pp. 51-54. 




NATIONAL AERONAUTICS AND SPACE ADMINISTRATION 
WASHINGTON, D. C. 20546 JULY 1974 



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THE INITIAL PHASE OF A TROPICAL CYCLONE FROM 
"SOYUZ-9" SPACECRAFT PICTURES 



7. Aullior(t) 

V. A. Bugayev, A. G. Nlkolayev, T. P. Popova 
and V. I. Sevast'yanov 



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Jilly 1974. 



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NASw-2483 



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I; ■ ■ ' 

Translation of "Nachal'naya faza tropicheskogo tsiklcna po 
snimku s kosmlcheskogo korablya Soyuz-9". Meteorologiya i 
gidrologiya*. No. 4, 1974, Pp. 51-54. 



16. Ab»trDCt 

The crew members of the spacecraft "Spyuz-9":JA. G. Nikolayev - 
and V. I. Sevast'yanoVfjItoolc, over the tropical latitudes of . the 
Atlantic Ocean, pictures of a convective cloud cell of a higher order 
than a simple cumulus. This cell is regarded by the authors of the 
article as being the initial phase of a tropical cyclone. However, 
unfavorable temperature conditions led to the breakdown of the 
convective cell, rather than to its transformation into a tropical 
storm. 



17. Key Word* (Selected by Author(s)) 



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THE INITIAL PHASE OF A TROPICAL CYCLONE FROM 
"SOYUZ-9" SPACECRAFT PICTURES 

V. A. Bugayev, A. G. Nikolayev, T. P. Popova 
and V. I. Sevast'yanov * 

During the flights of the "Soyuz" spacecraft, as is well 
knowrij a program of special meteorological observations was carried 
out [31,4,6]. The purpose of the program was to accumulate materials 
concerning the less well known synoptic situations and the details 
of objects such as the fronts and central parts of cyclones [2], 
etc. Details of this sort cannot be discovered either from the 
Earth, on account of the observer's limited field of vision, 
or from a meteorological satellite, on account of the low resolution 
of the equipment . 

A cosmonaut who Is a meteorologist or one who is trained for 
meteorological observations possesses different possibilities in 
this respect. An observer In space can be warned in advance from 
a meteorological center on Earth about those areas where interest- 
ing situations are to be expected, so that he can prepare in 
advance for selecting and photographing the mesostructures . On the 
other hand, tracing the changes in the situation along the orbit, 
he, himself, can also choose the area where interesting objects are 



V. A. Bugayev, Academician, Academy of Sciences, Uzbek SSR 
A. G. Nikolayev, Aviator- cosmonaut of the USSR 
T. P. Popova, Candidate of geographical sciences 
V. I. Sevast'yanov, Aviator-cosmonaut of the USSR, candidate of 

technical sciences 

**'Numbers In the margin indicate pagination of original foreign 
text . 



awaiting him. All of this creates broad possibilities for pro- 
ductive work of the observer on board a spacecraft. 

During the flight of the piloted spacecraft "Soyuz-9", 
cosmonauts A. CJ. Nlkolayev and V. I. Sevast'yanov observed and 
photographed various cloud forms characteristic for different 
cloud situations [4], Let us analyze one of these pictures, 
obtained on June 15, 1970 in the tropics of the soluthern 
hemisphere over the Atlantic Ocean. The synoptic situation 
observed here on that day was quite al usual one for June; that 
is, a subtropical anticyclone with Its ridge towards the Gulf of 
Gunea maintained a southeast trade wind In this part of the Atlan- 
tic. 

In Photograph 7 is given a montage of two television pictures 
from the satellite "ESSA-9" on June 15 at 15:00 hours, 26 minutes, 
40 seconds and at 15:00 hours, 31 minutes 00 seconds, Greenwich 
mean time. The zone of Intratroplcal convergence had few large /52 
cloud accumulations and, for this reason, was expressed unclearly 
in the pictures. However, its equatorial boundary can still be 
seen beginning from the Equator in the eastern part of the montage 
and extending to 5'^ north latitude In the western part, where 
there Is a solid cloud accumulation. A northeast trade wind 
can be traced clearly in the direction of the low cloud banks. 
In the Immediate vicinity of the Equator, there is an extensive 
zone which is almost cloudless, and farther south the cloud fields 
have the external appearance which Is characteristic for the 
trade wind zone of this part of the Atlantic. That is, there are 
closed cells of solid stratocumulus clouds in the zone adjoining 
the cold waters of the Bengal current, while there are fine areas 
of open cells over the warmer waters in the central and western 
part [9]. 



Cloud accumulations which are more vivid and, therefore, more 
highly developed In the vertical direction are observed west of 
15° west longitude and between 5° and 15° south latitude. 
Among the various cloud accumulations, when they are examined in 
greater detail, one's attention is drawn to the cloud accumula- 
tion which is bordered by the square in Photograph 7. This cloud 
accumulation is in no way notable at first glance. Somehow the 
accumulation I in its shape is reminiscent of a starfish with a 
more solid center and with offshoots going out on the sides from 
the center. On the south, in the corner of the square, there is 
a cloud bank II which adjoins this accumulation across a small 
cloudless interval. It ought to be noted that such a cloud 
accumulation was not here a few days before. 

This cloud accumulation was photographed by the crew of "Soyu2-9" 
from an altitude of 221 kilometers on June 15, 1970 at l4:20 hours 
Greenwich mean time [1], that is, approximately one hour before the 
satellite photographs. In the close-up photograph (Photograph 8), 
it is now little reminiscent of a star, although, if one were 
to look carefully and to distinguish the drawn out, white con- 
densed parts, they would form the same offshoots which in Photo- 
graph 7 give the cloud accumulation the shape of a starfish. In 
the photograph taken from the spacecraft, these white offshoots 
are masked by the bright shroud of the upper clouds and the 
fine banks of the lower clouds, which were not captured by the 
television equipment in Photograph 7. 

When we carefully examine the cloud accumulation in Photo- 
graph 8, we observe that its northern part consists of more solid 
clouds of curling, cumulus shapes. One receives the impression 
that it is precisely here that the basic convective ascent of the 
air takes place. The light foggy shroud of cirrus clouds covering 
the curling tops extends towards the south, the southwest, and the 
southeast. This can be seen especially clear in the stereoscope 



with the two adjacent photographs, which were obtained from the 
spacecraft after a short time interval (four seconds). 

The cloud "cover", moving out In a fan shape, has 
noticeable streaks aimed from the nucleus of the accumulation 
out towards its edges. However, on the edges of the cloud accumu- 
lation, the shroud of cirrus clouds Is sharply interrupted. This 
can be seen especially clear on the southern and southwestern 
outskirts . 

Such a structure of the cloud cover compels us to conclude 
that the accumulation is a large, active convectlve cell of a 
higher order than a simple cumulus. The basic ascent of the air 
takes, place in the northern part in an area of approximately 
10,000 km . However, on the periphery of the entire immense con- 
vectlve cell (the cloud formation has a diameter of 200 km), the 
descending movements carry the wind downward, the clouds are 
washed away, and the cloud edge acquires sharp outlines. 

The vertical structure of the cloud accumulation described 
here may be reminiscent to a certain extent of the structure of 
the very thick convectlve cloud shown in the picture In Photo- 
graph 9. This picture was taken by A. G. Nikolayev and V. I. 
Sevast'yanov from the spacecraft "Soyuz-9" on June 13 during 753 
the evening. The picture was taken from the side at an angle. 
In the right hand part, there is a tower of thick cumuli, the 
upper part of which spreads out to the left along the air 
stream to a great distance, approximately from the southwest 
to the northeast. The picture is really quite a unique one. 

However, let us return to Photograph 8. Around the cloud 
accumulation in the upper and middle troposphere, there is formed 
a ring of cloudless space with a width of about ^0 kilometers. 



Behind It, to the south and southwest, we see the solid cloud bank 
which we already mentioned above. In the lowest layers of the 
troposphere, in the zone of the cloudless ring, we can see clearly 
cumuli of types Cu med and Cu cong. In many parts of the picture 
they form banks, the orientation of which corresponds to the 
orientation of the southeast trade wind. However, in those 
places (the lower right-hand corner of the picture) where the 
orientation of the trade wind generally coincides with the 
direction in which the air is drawn into the large convective 
cell in the lower layers, the banks are less sharply accentuated 
and the clouds in them are larger. On the contrary, behind the 
large convective cell (the left edge of the picture), the direction 
of the trade wind is opposite to the direction in which the air is 
drawn in, the banks are more weakly accentuated, and they are 
partly broken up into small convective cells of the open type, which 
are characteristic for weak winds. The induction of air into a 
convective cell in the middle troposphere may also be seen along 
solid and rather narrow curved strips in the western half of 
the cloud accumulation. 

The cloud accumulation examined here, which amounts to a 
large convective cell, is highly reminiscent of the initial stage 
of a tropical cyclone. In its entire system of movement, there 
is not enough sharply accentuated revolution around the vertical 
axis. It is probable that, under some conditions which are as 
yet little known, such revolution does occur, and the cloud 
accumulation is transformed into a tropical cyclone. 

There is a series of photographs of tropical hurricane Bernice 
over the Pacific Ocean. In the initial stage of its development, 
when the tropical storm was a weakly accentuated depression, in 
its external appearance it was very similar to the convective 
cell we are examining, although its dimensions were twice as large 
(photograph of July 9, 1969)[8]. Later on, it developed into a 



tropical hurricane. In our case, such a development did not take 
place, and in the following days the convective cell could no 
longer be observed in the spacecraft data. 

One may also refer to Technical Note No, 124 published by the 
WMO [10], According to the classification of tropical and 
subtropical disturbances given there on the basis of spacecraft 
data, the earliest phase of development of a cyclone (stage A, 
Pig. IV. 5. 2) assumes the form of a solid amorphous mass of 
clouds composed of cumulus and cirrus forms, and also of strati- 
fied clouds of the middle layer in any combinations. In this stage, 
there is usually a spreading of the cirrus clouds in the different 
directions. 

One of the reasons why the convective cell was broken up 
without developing further was, probably, the temperature conditions 
on the ocean surface. As Is shown in the work of academician 
V. V. Shuleykin [7]j and also in accordance.' -with empirical data, 
tropical cyclones develop over ocean areas where the water sur- 
face has a temperature higher than 26° C. According to ship ob- 
servation data, the water temperature at that time was 
2k - 25° C in the waters of that part of the Atlantic where 
the cloud accumulation appeared. Generally speaking, it is always 
relatively cold here, since the cold waters of the Bengal current 
penetrate there, and tropical cyclones do not develop. 

The writers are grateful to Dr. A. V. Johnson, who kindly 
provided the photographs from the American meteorological 
satellite "ESSA-9". 



REFERENCES 

1. Bugayev, V. A. V ob'yektive - zemnaya pogoda. Most v kosmos.Z5iL 

(In the Lens - Weather on the Earth. A bridge into the 
Cosmos). Izdatel' stvo Izvestiya, Moscow, 197r>] 

2. BugayeVj V. A., T. P. Popova and V. A. Shatalov. Cloud 

Structure in the Center of a Cyclone According to Photo- 
graphs from Spacecraft "Soyuz-4". Meteorologiya 1 
gidrologiya^ No. 3, 1970. 

3* Issledovaniya prlrodnoy sredy s pllotiruyemykh orbital'nykh 
stantsll (Studies of the Natural Environment from Piloted 
Orbital Stations). Gidrometeoizdat ^ 1972. 

4. Ot kosmlcheskikh korabley - k orbital'nym stantsiyam (Prom 

Space Ships to Orbital Stations). Edited by G. S. Narimanov. 
Izdatel' stvo Mashinostroyeniye, Moscow ,j 1969 . 

5. Sevast 'yanov, V. I. Scientific and Technical Experiments 

Aboard the "Soyuz-9". Vestnik AN SSSR, No. 11, 1970. 

6. Khrunov, Ye. V. Possibilities and Perspectives of Carrying 

Out Meteorological Observations from Manned Spacecraft. 
Meteorologiya 1 gldrologlya. No. 9, 1971. 

7. Shuleykln, V. V.' Relationship Between the Intensity of a 

Tropical Hurricane and the Temperature of the Underlying 
Ocean Surface. Izvestiya AN SSSR, Fizika atmosfery T] 
okeana. Vol. VI, No. 12, 1970. 

8. Barnn, Robert A. The Eastern Pacific Hurricane Season of 

1969. Mon. Weather Rev., Vol. 98, No. 4, I969. 

9. Bugayev,jv. A. Dynamic Climatology in the Light of Satellite 

Information. Bull. Amer. Meteorol. Soc. , Vol. 54, No. 5, 
1973. 

10,. ..-The Use of Satellite Pictures in Weather Analysis and Fore- 
casting. Ed. by B. K. Anderson and N. P. Veltishchev. 
WMO No. 333, Techn. Note 124, Geneva, 1973. 



Translated for National Aeronautics and Space Administration 
under contract No. NASw 2483, by SCITRAN, P. 0. Box 5456, 
Santa Barbara, California 93108.