Spectral composition of earth radiation determined using monochromators installed on board Cosmos series earth satellite

Andranov, Yu. G.

Barkova, G. N.

Lebedinskiy, A. I.

English

NASA Technical Reports Server

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i’ ’ - . c  
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National Aeronautics and Space Administration 
Goddard Space Flight Center 
Contract No. NAS- 5 - 1248 7 
ST-AM-SPC -10649 
THE SPECTRAL COMPOSITION OF THE EARTH’S INFRARED 
RADIATION INTO SPACE ACCORDING TO THE MEASUREMENT RESULTS FROM 
EARTH’S ARTIFICIAL SATELLITES 
A. I. Lebedinskiy 
Yu. G. Andranov 
G. N. Barkova .. .. ET AL ...... 
(USSR) 
, 
- (ACCESSION/NUMBER) (THRU) 
4 OCTOBER 1967 
https://ntrs.nasa.gov/search.jsp?R=19670029378 2020-03-12T12:15:49+00:00Z
, .- 
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I 
d 
i ST-An-SPC-10649 
THE SPECTRAL CCMPOSITION OF THE EARTH'S INFRARED 
RADIATION INTO SPACE ACCORDING TO THE MEASUREMENT RESULTS FROM 
EARTH'S ARTIFICIAL SATELLITES 
* 
Pn;eer read by A. I. Lebedinskiy 
at the X COSPAR ASSEME3LY 
LONDON, ENGLAND, July 1967 
by A. I. lebedinskiy 
Yu. G.  Andrianov 
G.  N. Barkova ... ET AL ....... 
ABSTRACT 
The spectra of outgoing radiation were measured in the 7-3811 range 
using satellite-borne monochrmomators. 
tained. 
ground being 10 km. 
Up to 10,000 spectra were thus ob- 
It took 20 seconds to obtain each spectrum, the resolution on the 
The measured spectra were selectively compared with those computed from 
the data of aerological sounding. 
those obtained during the flight at meteorological stations at times close to 
the dates of aerological soundings. 
To that effect the spectra selected were 
The near-ground temperatiires were selectiveiy compared w i t h  the tempera- 
tures for various wavelengths measured from the satellite in cloudless regions. 
The connection was analyzed of the spatial distribution of radiation tempera- 
tures for various wavelengths with the distribution of cloudiness along orbits. 
A statistical processing of 1278 spectrograms was made for the Earth as a whole 
without breaking them up into latitude ranges. The unidimensional differential 
laws of distribution, i. e., the densities of probabili-ty of spectral inten- 
sity of the outgoing radiation have been approximated using the Pearson's cur- 
ves. 
tion in various spectral ranges are determined on the basis of the analysis of 
the two-dimensional differential laws of distribution. 
The correlation factors for the spectral intensity of the outgoing radia- 
The effective temperatures of radiation at various points of our planet 
in the 5-13 1~ range are very different, but beyond the longwave boundary of 
the CO, wavelength range these temperatures are con- 
strained within the narrow range of about 10°C order. 
b'ands in the 19-26 p 
* From rcvised rind improved preprint 
* 
* * 
Some of the Soviet artificial Earth's satellites of the "Cosmos" series 
were provided with diffraction grating spectrophotometers [l], with the aid 
of which a large number of spectrograms of the outgoing radiation were ob- 
tained in the 7 t 381~ spectral range. 
The instruments' optical axes were oriented along the local vertical. 
The devices measured the intensity of the radiation from a site of the Earth's 
surface of 7 by 10 km dimension at the average flight altitude of about 250 km. 
Presented below are the results of processing of a portion of the obtain- 
ed information using both the statistical method and that of the analysis of 
satellite measurements and the data from the ground meteorological network. 
The statistical treatment of the observation material consisted in piot- 
ting the curves of radiation intensity distribution in various spectral ran- 
ges and also in determining the correlations between the values of these in- 
tensities. 
spectrum was broken into 111 and 2~ intervals respectively in the 7 - 1 5 ~  and 
14-26~ ranges. 
grams in the 14 - 2 6 1 ~  range were utilized, which amounted to about one half 
of the total 
In accord withthe spectral resolution of the instrument, the 
fiis 1176 spectrograms in the 7 - 1511 range and 1287 spectro- 
of "COSMOS-45" measurements. 
Fig.1 presents the results bearing on the distribution of Earth's radia- 
tion intensity in various spectral ranges. 
values of x (radiation intensity in a specific spectral range), and in ordi- 
nates - tFe density of the probabi$lity f(x). 
10 - 11 
total of the recorded events ; in the 9 - 1 0 ~  range such cases amounted to 
four percent (4%) .  
interval of AX. 
Plotted in the abscissa are the 
The cases of overshoots of the processes observed on the film in the 
and 11 - 1211 spectral ranges amounted to six percent (6%) of the 
When treating these cases, they were ascribed to the last 
Plotted in the same Fig.1 are the Pearson curves [2 ] ,  which smooth out 
the obtained experimental statistical distributions. 
equations were used for these flattenings: 
Two types of Pearson 
The numerical coefficients in Eqs.(l) and ( 2 ) ,  calculated for the distribution 
in all spectral ranges, are compiled in Table 1. 
3 
0 
4 i 
0 4.0 7.0 
4 -  
2 -  
Fig. l a  
/ I  + 2up 
L 
3.0 
a 
20 + 22JL 22+ 2 4 p  
f.0 0 to 0 
4 
7 - 8 
8 - 9 
9 - I 0  
IO - I1 
I1 - I2 
1 2  - I 3  
I 3  - I4 
I4  - I 5  
I 4  - I6  
I 6  - I 8  
I8 - 20 
20 - 22 
22 - 24 
24 - 26 
 
1,o 
1969 
i ,53  
2 , i O  
2,77 
2.23 
I ,32 
0,75 
0,59 
O,35 
I,U2 
0.88 
0.66 
0.52 
Yo * 
1 0 3  tm‘lu 
W 
i ,59 
0,99 
0.99 
0,62 
0,55 
0,53 
0,7I 
O,I8 
6,64 
3,60 
0,4Q .IO4 
3,94 
4.56 
6,85 
6.09 
:76 (0 
46 ,7 
I , I 6  
0.68 
0,52 
3.06 
2,98 
0.24 
I3,40 
7.15 
13.10 
5.74 
3,48 
M2 
1.31 
I4,30 
71,80 
0,57 
0.13 
0,23 
6.94 
-5,76 
I5,70 
7.04 
I9,QI 
2.38 
2.45 
I ,56 
A ,  
0- c m z p  
I,57 
I9,60 
3.90 
I ,62 
2,IO 
I ,66 
I-,25 
0.28 
0,023 
iJ,7I 
0,26 
0,93 
0,2I 
0.11 
3 w  
A2 
 IO-^,^^ 
0.34 
i ,59 
6 ,(12 
0.80 
0,42 
0.72 
2,83 
0.47 
1.52 
0.37 
1,39 
(1.17 . 
0,70 
0.54 
Fig.  2 
5 
Fq. (1) was used for the majority of spectral ranges and Eq. (2) - for the 
14i15, 181 20, 221 24 and 2412511 ranges, 
Fig.2 shows the numeiical characteristics of the obtained statistical dis- 
tributions as a function of the wavelength , X is the mathematical expectation, 
M is the mode, u is the mean root deviation (left scale). Besides, Fig.2 pre- 
sents the dependence of the effective temperature of the absolute blackbody 
corresponding to the Earth's radiation intensity; T, is the temperature found 
from the mathematical expectation of the intensity;x TM is that found from the 
mode (the right scale). 
they reflect the character of the Earth's radiation as a whole, without divi- 
ding it into ensembles (sunlit and dark sides, cloud and cloudless conditions, 
land and sea, geographical coordinates etc.) . The latitude dependence of ra- 
diation intensity is presented in Fig.3 for various spectral ranges. 
The above distribution laws of radiation intensities are global, i. e., 
It follows from the results obtained that the minima of radiation intensi- 
ty (minima of the values of 2 and M) are narrow laws of intensity distribution, 
i. e., the minima of intensity fluctuations (minima of the values of U) corres- 
pond to the bands of atmospheric gas absorption (9.611 for ozone and 1 5 ~  for 
carbon dioxide). 
"window" of the Earth's atmosphere ( 8 i 12~) and the distribution function is 
close to the law of equal density. 
has a small scatter with respect to the amplitude and a weak latitude depend- 
ence. is within the 265 - 
272' range and TM is within 267 - 276' K. 
on the average close to the spectrum of the absolute blackbody with tempera- 
ture of about 268'. 
7%e intensity distribution is broadest in the transparency 
The distribution of radiation intensity in the 14 i 26p spectral range 
In the 18 i 26p spectral range the temperature T- 
X 
Hence the spectrum of the outgoing radiation in this wavelength range is 
For the study of radiation intensities' correlation dependences in dif- 
ferent spectral ranges the two-dimensional laws of Earth's radiation inten- 
sity distributions have been plotted for all combinations of spectral ranges. 
As an example, Fig.4 presents the two-dimensional distributions for the 
spectral ranges corresponding to two bands of weak water vapor absorption 
(8 1 9 p  and 10 i llp), as well as to the bands of weak absorption of water 
vapor and strong absorption of carbon dioxide (11 1 l& and 14 i 15p). 
numerals inside each square of the grid in Fig. 4 denote the number of the 
event when the radiation intensities in both spectral ranges discussed has 
a magnitude limited by the values of the respective sides of the square. 
The dotted lines in Fig.4 are the plots ff the dependences linking the inten- 
the centers of the spectral ranges examined. The circles on the curves denote 
the radiation intensities of the absolute blackbody with temperatures from 200 
to 30'K inhccretions of 20'K. 
The 
.. . 1: -A?-- r AI- -L--l.*+.. L1nrLh-Ar 4 -  . . r n \ r a l a n r r + h c  rnrrecnnnAing t _ ~  
SlCleS 0: 1 ~ U l d L l U I l  G L  L116 au3uAut.k U A ~ L ~ ~ \ U ~ - J  W V ~ . ~ ~ ~ . . ~ - . . -  --__ - r------- 
T a b l o  2 .  
I I I I I I 1 
7 
%p 
8 - 9.9 
9 
9 .s t 5.9 
I1 +b1.6 
" 2.2 
14 + 2.3 
14.5 +10.0 
+ 2.9 
I O  + 4.3 
12 - 1.0 
13 
"C ' 2  Tcxi1.W ~ n e a s  ,
10.3 
4.4 
5.3 
4.9 
4.4 
4.: 
j b 1  
4.0 
11.6 
I 
8 
The correlation momenta K ,  the correlation factors 1, the inclination 
angle of the main axis of scattering 01, as well as the mathematical expect- 
ations xl, x2 and the mean root deviations a l ,  ~2have been computed for the 
obtained two-dimensional laws of intensity distributions. 
these numerical characteristics for both examples of Fig.4 are compiled in 
Table 2. The main axes of scattering are shown as the dash-dotted lines in 
Fig.4. 
The values of 
The data obtained are evidence that the strong correlation link is bet- 
ween the radiation intensities, the absorption bands of the same atmospheric 
gas for 8 : 9 p  and 10 t 11p , and that the correlation link between the radia- 
tion intensities in the bands of different gases (water vapor and carbon di- 
osidc) is weak. 
Simultaneously with the above statistical processing of the observation 
material the spectra of outgoing radiation measured from COSMOS satellites 
were compared with the corresponding time and location data of ground meteo- 
rological observations and with the data resulting from calculations of ra- 
diation in various spectral ranges. 
We shall consider, first of all, the problem of agreement with calcula- 
tion data. The methods of such calculations were described in [ 3 ] ,  where some 
results have also heen given of the comparison of spectra in the 8 I 15p range 
measured on COSMOS-45 with the calculated ones. Here we shall discuss the 
similar results in the 8 f 35v spectral range. Compared again were the spectra 
measured from the satellite near the stations of aerological soundings at mo- 
ments of time close to the synoptical dates. 
made for stable cloudless conditions. 
First of all comparison was 
SufEiciently typical examples of such a comparison are illustrated in 
Fig.5. 
ted radiation temperature is strikingly different for the various spectral 
ranges. 
temperatures €or some wavelenths (taking into account the sign and with res- 
pect to modulus) are compiled, for example, in Table 3 .  These differences 
are especially great in the absorption bands, but they are smaller in the 
transparent spectral ranges. 
It may be seen that the degree of agreement of measured and calcula- 
The mean differences between the calculated and measured radiation 
'Ihe differences in the absorption bands are systematic, which is con- 
firmed by the closeness of the values dland 6 2  to one another. 
ence between the calculated and measured may stem from the fact that the 
scheme for calculating the radiation [3] fails to describe quite correctly 
the true process of radiation transfer in the atmosphere for spectral ranges 
related to absorption bands. 
The differ- 
Tt is possible, however, that the absence of sufficiently detailed and 
accurate information on ozone and C02 distribution and on the stratification 
-l- +- ...-.,... -+...-,. , , - , I  h..,.,:A:+.. :- +h, ,+.+,.-.I,- ;- +h- -C +I.- rl;CC..---c, 
VI L L l 1 1 1 l L  L r l L L A l L  t L 1 1 L 1  I L L U . : L L l I L . y  1 1 1  C11L 3 C l U L U J ~ l l L L L ,  13 L l L L  LUU.Yb VL L L L L  U L L L L L L L L L L .  
9 
cloudhess 
- measured --- eatcuPated 
210 1 
. Fie5 Fig 6 
10 
We shall now consider the problem of connection of radiation tempera- 
tures of outgoing radiation in various spectral ranges with the distribution 
of cloudiness and temperatures at various atmospheric leveis. 
To that effect we plotted the distributions of temperature and cloudi- 
ness along orbit trajectories on the basis of cloudiness charts and isotherms 
at various levels. 
was plotted for various wavelengths. 
and 15 - 35u ranges were borrowed from the measurements [l] of respectively 
the shortwave and longwave spectra. 
At the same time the distribution of radiation temperatures 
The radiation temperatures in the 8 f 151~. 
Examples of distributions of cloudiness, near-ground and radiation tempe- 
ratures for some wavelengths along the orbit trajectory (orbit 28 of COSMOS-65 
on April 19, 1965 at about 0300 hours Moscow time) are shown in Figure 6 .  
The orbit in question is illustrated in Fig.7. 
corresponding to the numbers in the abscissa of Fig.6 are shown along the tra- 
jectory. Besides, Fig.6 shows the main types of clouds which were present in 
the region. 
The numbers of the spectra 
The information on cloudiness in some localities wzs completely absent 
and only the amount of clouds without specification of the type was known for 
other localities. 
It is nevertheless possible to get a general idea about the cloudiness distri- 
but ion. 
This refers more particularly to the near-equatorial regions. 
In the case under consideration the main cloud masses were located over 
No.C,mada from a point with 65' N.latitiude and 130° W. longitude up to the 
eastern coast of North America. Substantial and complete cloud forms with 
stratocumuli, also-cumuli and stratonimbi were observed. The cirrus and cirro- 
stratus clouds were also absent. 
Strato-cumulus clouds were miniy observed over the Pacific, while cloud- 
less conditions prevailed over North American coast in Alaska and the Aleutian 
island regions. 
regions and in the tropical regions it crossed localities with cumulus clouds. 
In the Atlantic the satellite orbit crossed mainly cloudless 
The above described features of cloudiness distribution are reflected 
in the distribution of radiation temperatures, as is shown in Figure 6 .  Natu- 
rally, these features are most pronounced for the distribution of radiation 
temperature in 8 f 121~. "transparency window". 
;n the cloudless or little cloudy regions the radiation temperatures in 
the "transparency window'' are close to near-ground temperatures of the air. 
??IC values onci the distribution of deviation of radiation temperatures from 
ti:<' near-ground one are quantitatively illustrated in Table 4 ,  where the 
1-ciiirrences of the differences are given: 
t, ~2 = 'l'rad[luPj - 'iiir - A~ = irnd ( i i p j  - 'rair 
11 
It is of interest to note that the field of cloudiness affects the radia- 
tion to a smaller or greater extent practically in all spectral ranges beyond 
the "transparency window" as well. 
spectral range. 
spectral range is similar to the temperature distribution in the 8 : 12p range. 
In the 17 I 2Op range (with peak at 18 t 19p), the temperature themselves are 
5 to 7' lower than those in the 8 I 12p range in cloudless regions. 
This refers especially t o  the 17 t 2011 
The character of radiation temperature distribution in this 
In cloudy regions this difference decreases down to zero. It is quite 
understandable if one takes into account that the optical atmospheric depth 
above clouds is appreciably less than that over the clear regions of the Earth's 
surface. 
The influence of cloudiness on the outgoing radiation is not so appreciable 
As should be expect- in the spectral ranges related to 
ed, the difference in the radiation temperatures for the cloudy and cloudless 
regions in the CO, absorption band is small. 
the absorption bands. 
A similar effect may be noted for wavelengths longer than 2 2 p .  However, 
in this case the influence of cloudiness is more appreciable than in the case 
of CO, absorption band. 
tion and cloud distribution allows us to conclude that the cloudiness affects 
the characteristics of the outgoing radiation of the Earth's surface and atmo- 
sphere in all infrared spectrum's ranges to a greater or lesser extent. 
Thus, the joint analysis of spectra of outgoing radia- 
Besides, the orbit distribution of radiation temperatures in various 
spectral ranges and the vertical cross-sections of the temperature in the atmo- 
sphere based on the data of aerological soundings were jointly analyzed. The 
purpose of this analysis was to find the atmospheric layers responsible for 
the generation of outgoing radiation in one or another spectral range, i. e., 
to determine the so called effective radiation levels. Orbits close to the 
syncptical dates were as usually selected for the acalysis. 
that the determination of the effective levels of radiation in the spectral 
ranges differing by more or less considerable absirptions is of utmost interest 
since the effective level for the "transparency window'' is none other than the 
Earth's surface or the cloud surface. 
It is natural 
Figure 8 shows an example of the vertical cross-section of temperature 
in the atmosphere in the plane of orbit 28 (see Fig.7) with the curves of 
radiation temperature distribution for the wavelengths of 14, 18, 23 and 3211 
plotted on it (the numbers of spectra are indicated along the abscissa axis!. 
It is easy to see that the variations in altitude of the effective radia- 
tion level depend on the degree of radiation absorption in the atmosphere in 
either spectral range. Thus, for 1 8 ~  wavelength (rather "transparent" spec- 
tral range) these variations cover practically the whole troposphere. They 
are much smaller for the remainder of wavelengths and they refer only to the 
upper troposphere; the effective radiation level fluctuates for 14p from 5 
to 8-km, for 2 3 p  from 4 to 8 km and for 32p from 5 to 11 km 
12 
23F 
. . . .. . . ._. 'V ---.. P . d  'C 
5 15 20 25 UumBer 30 of spectrum 
Fig 8 
Despite the fxt that in these variationsthe cloud altitude changes are 
of considerable importance (see Fig.6), it is nevertheless possible to note 
the latitude dependence of the altitude of the effective level connected with 
the latitude dependence of moisture content in the atmosphere (decrease of 
optical atmospheric depth with increasing latitude). 
atmosphcric layers to the outgoing radiation for various latitude belts. 
Thus. it has been possible to get an idea about the contribution of various 
REFERENCES 
1. A. I. LEBEDINSKIY, D. N. GhlVATSKIY, V. I. TuLuPoV ET AL. The infrared 
spectroscopy of the Earth's heat radiation." Issl. kosm. 
pros trans tva" , Moscow 1965. 
2. V. I. ROMANOVSKIY. Matematicheskaya statistitca. Tashkent 1961. 
3 .  A. I. LEBEDINSKIY, V. G. BOLGYREV, V. I. 'IULIPOV ET AL. The spectrum of 
of the Earth's heat radiation according to observations from 
COSMOS-45, COSMOS-65 and COSMOS-92 satellites. 
Space Research VII, cIa, 1966. 
;)repared by ANDRE L. BRICHANT 
on 2 - 4 October 1967 
from a preprint X COSPAR. 
London 1967 


The spectral composition of the earth's infrared radiation into space according to the measurement results from earth's artificial satellites

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