Ozone depletions in the polar stratosphere during the energetic solar proton event on 4 August 1972 were observed by the backscattered ultraviolet (BUV) experiments on the Nimbus 4 satellite. The observed ozone contents, the ozone depressions and their temporal variations above the 4 mb level exhibited distinct asymmetries between the northern and southern hemispheres. Since the ozone destroying solar particles precipitate rather symmetrically into the two polar atmospheres, due to the geomagnetic dipole field, it is suggested that these asymmetries may be explained in terms of the differences in dynamics between the summer and the winter polar atmospheres. In the summer (northern) hemisphere, the stratospheric and mesospheric ozone depletion and recovery are smooth functions of time due to the preponderance of undistributed orderly flow in this region. On the other hand, the temporal variation of the upper stratospheric ozone in the winter polar atmosphere (southern hemisphere) exhibits large amplitude irregularities. These characteristic differences between the two polar atmospheres are also evident in the vertical distributions of temperatures and winds observed by balloons and rocket soundings

Heath, D. F.

Maeda, K.

English

NASA Technical Reports Server

General Disclaimer 
One or more of the Following Statements may affect this Document 
 
 This document has been reproduced from the best copy furnished by the 
organizational source. It is being released in the interest of making available as 
much information as possible. 
 
 This document may contain data, which exceeds the sheet parameters. It was 
furnished in this condition by the organizational source and is the best copy 
available. 
 
 This document may contain tone-on-tone or color graphs, charts and/or pictures, 
which have been reproduced in black and white. 
 
 This document is paginated as submitted by the original source. 
 
 Portions of this document are not fully legible due to the historical nature of some 
of the material. However, it is the best reproduction available from the original 
submission. 
 
 
 
 
 
 
 
Produced by the NASA Center for Aerospace Information (CASI) 
https://ntrs.nasa.gov/search.jsp?R=19790008306 2020-03-22T01:41:50+00:00Z
... 
NI\SI\ 
Technical Memorandum 79696 
(NASA-T ~-79696) ASY"~ETRIES IN OZONE 
DEPRESSIONS EE!WEEN THE POlAF STBATCSPHE RES 
FOLLOWING A SOLAR PSOTON E VE~! ( NASA) 10 F 
N79- H; 4 77 
He A02/MF AO 1 CSCl 04A 
G3/46 
Onclas 
1357] 
Asymmetries In Ozone 
Depressions Betvveen the 
Polar Stratospheres Follo\Nlng 
A Solar Proton Event 
Kalchl Maeda and Donald F. Heath 
NOVEMBER 1978 
National Aeronautics and 
Space Administration 
Goddard Space Flight Cent. 
Greenbelt, Maryland 20771 
, 
\ 
\. 
ABSTRACT 
Ozone deplet i o~ in th pol ar s tratosphere during th e encrgetic so lar 
prot on e en t on Augu s t 19 ~ w r e observed by the back scattered ultraviolet 
(BU ) experiment on the Nimbus 4 s t el lite. Th observed ozone contents, the 
ozon e depress ions ~ nJ their temporal variations above the 4 mb level (~3 ~ km) 
exhibited distinct asymmetries betw en the northern and southe rn hemispheres. 
Since the ozone des troy ing solar parti cles prec ipi tat e rather synunetrically into 
the two polar atmosphere s , due to the geomagnet ic dipol e field, it is suggested 
that these asymmetri es may e expl ai ned i n terms of the difference s i n dynamic s 
between the summer and the wi nter pol ar atmo spheres . In the summer (north e rn) 
hemi pherc, the tra t ospherl and mesospheri o:one depl eti n cnd re very a r e 
smoo h fun c t ion o f ti m du t o the ~repond eran e of und is turbed order l flow 
in t hi s r egion . On the 0 h r h nd . th t empor a 1 var i t i n o f the upper s t r, t o-
spherl' ~ ne in hc wi nter p l ~ r atmo spher e (5 uthern h em i ~phcre ) x li bits 
larg 'jlllliitude i.rre Ila r iti - . Thc s .h3r3c ri ti .: differences betwe n the 
two p lar at mo phere- a r 1 ':0 ev'd n i n t he' v ' r t.l a d i ' tri buti n ' of temp-
eratu re s and win S ob 'erv 'd l)' ' 11 0 ns and f' , ) c t soun in's, 
- 1-
The first observation of large-scale stratospheric ozone reduction due to 
precipitating energetic solar protons was made by the backscatt ered ultraviolet 
(BUV) experiment on the Nimbus 4 satellite during the solar flare event on 4 
August 197 2 (Heath et al., 1977). It was concluded that this ozone depression 
was due to solar protons because the observed ozone depression was preceded by 
the detection of hi gh intensity solar protons and the latitude denendence of the 
observed ozone depletion was limited to the polar regions with geomagnetic 
latitudes higher than roughly 55 0 in both hemispheres. Prior to this observation, 
the reduction of stratospheric ozone during solar flare events was predicted by 
Crutzen et al. (1975). 
The purpose of thi s letter is to descrihe the spatial and temporal asymme-
tries in the stratospheric ozone depletions occurring between the northern and 
southern hemispheres after the solar flare and discuss possible causes of 
these asymmetries. 
Tn Figure l(a,h and cl,* the columnar contents of atmospheric ozone above 
the 4 mb l eve l in the unit " of atmosphere-em (atm-cm) obtained by the Nimbus 4 
BUV are pl otted agains t time fo r the period extendi ng from day 180 to day 250 in 
1972. The major sol ar flare erupted at about 06 UT on 4 August (Day 217) (~Iartes, 
1973; IJakura, 1977 )" This flare event \ as the mo t intense on record in the 
la "t 26 years (Heath et al .• 1977). Figures (a) and (b) correspond to the data 
at 70° and 70 0 S, respe~tively" Fig r (c) presents the latitudinal d nendence 
of t i.e observed ozone depression event i n hath hemispheres. From these figures, 
one can see the fol lowing : (1) The mean value of the ozone content above the 4 
mb level prior to the so lar event in the northern hemisphere (summer) is less 
than that of the sout hern 
* The ozone data used in this investigation are from the original processing of 
the Nimhus 4 data from the BUV exped ment. While the final processing is 
expected to improve the quality of the derived ozone data we have no reason 
to be lieve that it will alter the conclusions contained in this paper. 
-~-
hemisphere (winter). (2) On a time scale of days, the ozone columns above the 
4 mb level in the northern summer hemisphere are less disturbed than those in 
the southern winter hemisphere. (3) The reduction of ozone after the August 4 
flare event rang~s from a mean of 0.0138 atm-cm. for the pre-flare value to a 
mean of 0.0117 tm-cm, i.e., a 15.5% reduction at 70 0 N. On the other hand, at 
70°5, it changes approximately from 0.017 to 0.011 atm -cm. which is more than 
40%. (4 ) The recovery at 70 0 N is approximately monotonic with a time constant 
of the order of 20 days at the 4 mb level, ~lthough the ozone depletion in the 
band of 75°-80°' . hows no evidence of recovery for a period of one month after 
the event, as a ll be seen fr om figure ec) (Heath et al., 1977) . The time vari-
:1tion at high lat i tud s in the southern hemi phere indi ate l arge flue uations 
not only in the r cov ry per iod but also during the ent i re period of obsp rvati on . 
Due to the 1; rge temporal fl uctuations of ozone in the southern hemi phere, 
one might initially question the validity of the data. In the following, however, 
we show that thes e fluctuations are real and can be explained on physical grounds. 
We also discuss the possible causes of the mean ozone asymmetries between the 
hemisphere s which may be due to interhemispheric differences in the dynamics of 
the upper polar atmospheres , solar illumination and vertical temperature structure. 
(1) Temporal Variations 
The precipitation of sol r flare particles, consisting mostly of protons of 
eve a1 tens of M V, with a few alpha particles (of the order of 10% of protons ) 
and :l smal ler f raction of heavy ions (Yates et al., 1973), should be symmetric 
betw en t he t wo hemispheres, due to the geomagnetic control of these incident 
partic1 hser~, ti ns f th e reductions in ozone and t heir temporal varia-
tion ~ are, hOhe ~r, quite different i n each hemisphere as can be seen in Figure 
1. These differenc . can be attd uted to the differing dynamical states of the 
-3-
pola!' upper atmospheres in summer and winter as indicated by the thermal struc-
ture and its time dependence in Figure 2. This figure shows the vertical temp-
erature distributions up to the 100 km level (a) in winter and (b) in summer as 
observed at Barrow, Alaska (7l 0 N) from combined meteorological rocket soundings 
and radio-sonde observations during 1969 winter and 19i1 summer periods (Smith 
et al., 1971, 1974; Theon et al . , 1972). From these figures one can see that 
the winter polar atmosphere (Figure 2a) exhibits large disturbances in contrast 
to the summer polar atmosphere (Figure 2b). Correspondingly, instead of the 
monotonic recovery of depressed ozone in the summer stratosphere, the depleted 
ozone follows irregular variations as suggested by the vertical temperature 
variations in the winter stratocphere (Figure 2a). The variations are due to 
disturbances associated with planetary waves which propagate upward beyond the 
tropopause only during polar winter when the wind system in the lower strato-
sphere is moderately westerly (Charney and Drazin, 1961; Dlckinson, 1968; Matsuno, 
1970; Hirota, 1971, 1976; Austen et a1., 1976). It should be noted that the 
presence of waves in the polar winter atmosphere and the relative lack of waves 
in the summer atmosphere is also reproduced by the numerical experiments of the 
general circulation model of Cunno1d et al. (1975, Figure 10 for example). 
Such waves are also indicated by balloon and rocket soundings of the polar 
atmosphere (Theon et al., 1972). Internal gravity waves also contribute to the 
temporal structure of the polar winter atmosphere. Their amplitudes in the 
stratosphere are, however, not as large as those of planetary waves. 
(2) Mean distributions 
The higher mean ozone values in the winter stratosphere relative to those 
of summer (Figure 1) have been noted previously by Heath et a1. (1974) and are 
also consistent with other OGO-4 ozone observations (London et al., 1977). These 
higher values are mainly due to the wintertime increase of the transmissivity of 
-4-
the orographi dl ly excited pl anetary waves and the associate i n Tease in eddy 
transport s of oz ne from the t ropical upper stratosphere (where i t is pr duced) 
t o higher l ati tud es (Dutsch, 1971). Other smal ler contri but ions to the higher 
winter me an ozone a lues are: (1) he nightt ime enhancement of mcsospheric 
ozone (Hunt, 19b , Reed, 1 68 ; Maeda and Aikin, 1968 ; Hilsenrath, 1971), bej ng 
greater i n w' ntcr t han summer , eX .:nds t o the 4 mb Ie 1. (2 ) The net pr ducti. n 
0:0 e in h cooler wi n er . tmosphere i s great e r th ' n that of the 
summe (C ruL n, 197 4) since he prouu ti on and de t r u ti o 
and incre:.lsc with emF-e "F! lUre, re '.le tive ly. 
o on decr ' e s 
i'- jnaIl y , t h uld be not d that not 0nly i h ummer - will t er oz ne 
, ymmet.ry e f e t) r u ': '. tl by planet ry w ve s hilt. ills the inter-
h mi spher ' a s ymme try of the ot a l u: one content (ozon max i mum i ' large st in 
the northe r n hemi sphere). Thi s can be ascribed t o two factors: (1) Th ampli -
tud es of the orographically excited p l anetary waves are larger i n the northern 
hemisphere than t he southern hemi sphere because of the larger continental surface 
area in the northern hemisphere in contrast to the dominance of s~~oth ocean 
surfa ces in the sout hern hemisphere. (2) The transmissivity for planetary 
waves is largest in the late winter. 
-5-
REFERENCES 
Austen, M. D., J. J. Bernett, P. D. Curtis, C. G. Morgan, J. T. Houghton, G. D. 
Peskett, C. D. Rodgers, and E. J. Williamson, Nature, 260, 594-596, 1976. 
Charney, J. G. and P. G. Orazin, Propagation of planetary-scale disturbances 
from the lower into the upper atmosphere, J. Geophys. Res., 66, 83-110, 1961. 
Crutzen, P. J., A rev i ew of upper atmospheric photochemistry, Can. J. Chern., 
52, 1569-1581, 1974. 
Crutzen, P. J . , I.S.A. Isaksen and r.. Reid, Solar proton events: Stratospheric 
sources of nitric oxide, Science, 189 , 457-459, 1975 . 
Cunnold, D., F. Alyea, N. Phillips and R. Prinn, A three-dimensional dynamical -
chemical model of atmospheric ozone, J. Atmos. Sci., ~, 170-194, 1975. 
Dickinson, R. E., Planetary Rossby Waves Propagating Vertically Through Weak 
Westerly Wind Wa' .. e Guides, J. Atmos. Sci.,~, 984-1002,1968. 
Dutsch, H. U., Photochemistry of atmospheric ozone, Advance in Geophys., ~, 
219-322, 1971 
Hakura, Y., Interdisciplinary summary of solar/interplanetary events 
during August 1972, Space Sci. Rev., ~, 411-457, 1977. 
Heath, D. F., E. Hilsenrath, A. J. Krueger, W. Nordberg, C. Prabhakara and J. 
Theon, Observations of the global structure of the stratosphere and meso-
sphere with sounding rockets and with remote sensing techniques from 
satellites, in Structure and Dynamics of the Upper Atmosphere, Edited by 
r. Verhiani, F.1serier Scientific Publishing Co., Amsterdam 1974 . 
Heath, D. F., A. J. Krueger and P. J. Crut zen, Solar proton event: Influence 
on stratospheric ozone, Science, 197, 886-889, 1977. 
Hilsenrath, E., Ozone measurements in the mesospher e and str~tosphere during 
two signi ficant geophysical events. J . Geophys. Res ., ~. 295-297, 1971. 
Hirota, T., Excitation of planetary Rossby waves in the winter stratosphere by 
periodic forcing, J. ~1et. Soc. Japan, 49, 439-449, 1971. 
-6-
Hirota, I., Seasonal variation of planetary wave s in the stratosphere observed 
by the Nimbus SCR. , Quart . J. Roy . Met. Soc., 102, 757-770, 1976. 
Hunt, 8. G., Photochemi stry of ozone in a moist atmosphere, J. Geophys. Res. , 
2!, 1385-1398, 1966. 
London, J., J. E. Frederick and G. P. Anderson, Satellite observations of the 
global distributions of stratospheric ozone, J. Geophys. Res., 82, 2543-
2556, 1977. 
Maeda, K. and A. C. Aikin, Variations of po l ar mesospheric oxygen and ozone 
during auroral events, Planet. Space Sci. , .!..§., 371 - 384, 1968. 
Martes, M. J ., Contribution of Meudon to the observat i ons of the August solar 
events, Report UAG-28, World Data Center A, Part I, 46-55, 1973. 
Matsuno, T. , Verti cal propagation of stationary planetary waves in the winter 
northern hemisphere, J . Atmos. Sci., 27, 871-883, 1970 . 
Reed, E., A night measurement of meso spheric ozone by observat ions of 
ultravio let ai rg1ow, J . Geophys . Res. , 73 , 2951- 295 7 , 1968. 
Smith, W. 5., J . S. Theon, J. F. Casey, A. Az a r T3ga and J . J. H rvath, 
Temperature , ?r essure, Density and Wind Mensur mc nt s i n th Stra t osph r 
and M so phere , 1969 , NASA Tech . ote R-3 0 , Mar ch 19 1 . 
Smith, W. S., J . S . Theon, D. U. Wright, J r ., J . Ramsdale and .1 . .1 . H Tva h 
Measurem nt s of the Struc ture and Cireul ti n 0 
1es phere 19 1-_. I AS T ch. No te R- Ih Januar 19-d . 
Theon, J. 5., W. S. Smith, J. F. asey and B. R. Kir wood, . ~e m an bs r v 
met eorologica l structure and circulation of the str t ospheTe and meso ph re, 
NASA TR R-375, Mar ch 1972 . 
Yates, G. K., L. Kat z , B. Se ll ers anu ~ . A. Hanser, Proton and alpha part icl e 
f1~xp ~ 0bserved aboard OV5-6 in August 1972 , Report UAG- 28, World Da ta 
Center A, Part II, 348-353, 1973. 
-7-
Fg. 1 
Fig. 2 
FIGURE CAPTIONS 
Zonally averaged total ozone above the 4-mb level during July-
August 1972. The solar proton event occurred on 4 August (day 217). 
(a) at 70 0 N, (b) at 70°5 and (c) at 6-latitude bands, (70°5, 60°5, 
0°, 60 0 N, 70 0 N and 80 0 N). The vertical bars for each data point in 
(a) and (b) inuicate the standard deviations of all data obtained in 
the latitude band of that day, 
Vertical temperature distributions at Barrow, Alaska (71 0 N) 
observed by radio-sonde (up to around 35 km) and by sounding rocket, 
(a) in winter 1969 (data points marked by triangles, open circles 
and closed circles are II January 1015 UT, 19 January 2132 lJT and 26 
January 0500 UT, respectively, Smith et al., 1971), and (b) in 
summer 1971 (data points marked by triangl es , open circles and 
closed circles are 24 June 1500 UT, 2 July 1959 UT and 12 July 
1518 UT, respectively, Smith et al., 1974). 
- 8 -
- 01 7 700N (SUMMER) ~. L (a) 
~ I I ~ ~ 70"S !;( . 0 15 ~ 1 • 'I 1 o. 
- , .018. • • • ~ .016 ( c) • .. '" 00 : •• o •• 0 0 
.013 • • • •• 0 ~ .014. • 
o .~ 
m . 2. 
'" .01 1 10'8 'II 
OJ _ • •• , ~ f- i •• ", •••• ,.. ... N iulllllll! 111111" I, i' 1'1111 250 U .018 0....... . . , o .009 -- 200 110 • .~ o. • • .. • 0 
80 190 ~ 018 --~ ____ .:....a'--. ___ _ ~ . • o· • ~ .. ~ 023 r-~~~--- --__t__ 70"S (WINTER) m ~ _,Y,"," .'- ~h_ 
. ! .018 • - - • _ _ ~ 
.021 r-- (b) 
~ 
y 019 
:E ' 
~ 
• c( 
i .011 r 
w 
~ 0 15 ~-
III nit ~ . I· ~ 01 3 -
1111 II flt 
o · 
N 
0 
w 
> .016[ &,.. 2 ouN J 
: .018 
2 .016t~._~J * .... ..".,: • ." 
o 7CfN , j 
.014~~ -~;- ~.,.".., .,. ... 
e., e ,...me • ~". 
.012 ., ... 
e WN I 
014 _...... ~ O'...,,~+ 
.::: = ::~ -:: ~ 
180 190 200 210 220 230 240 250 
DAY NO. (1972) 
I Il I '.l.. 009 ,-, ~ 1_
. BO 1 SO 
. ~ I 
..,t) 
;"-=J 
-:; 10--4 
W 
BARROW. ALASKA 171· NI 
WINTER SUMMER 
100 100 
.., .., 
~8) ! 8)r (a) (b) ~ w 0 
~40 :) t:40 ~ ~ 
20 20 
0 - o . 18) 1111 200 220 240 2S) 8) 120 140 18) 18) 200 220 240 2S) 8) • :IX) 
TEMPERATURE (OK) TEMPERATURE (OK) 


Asymmetries in ozone depressions between the polar stratospheres following a solar proton event

Abstract

Similar works

Full text

Available Versions

NASA Technical Reports Server