A three year ice
package
From highest
warmth to lowest cold
Last decade
before WWII was the warmest
period since meteorology started recording around the globe in the 18th
century. To this extent, the weather had been gaining from
‘strength to
strength’ since the Little Ice Age, which ended around the
middle of the 19th
century. Since then global temperatures had risen steadily. Even
eruption of
the Krakatoa volcano in Indonesia on August 27, 1883, whose dust clouds
spread
around the globe and blocked solar radiation by up to 20% for three
years
(Lit.: Wexler, Effects)[1],
had no significant effect on the weather and the climate. At least, no
occurrences of record weather conditions had been reported from
anywhere.
About half a
century after Krakatoa
eruption, the weather played havoc in Europe during the winters of
1939-42.
Suddenly, there were three arctic winters that could be included in the
league
of the coldest winters during the Little Ice Age one hundred years ago.
There
were no major volcano eruptions, no earthquakes, no sunspots, nor did a
big
meteorite fall to the earth anywhere. Only a war had been started in
Europe in
September 1939. Suddenly, ‘a force’ emanated which
needed the shortest period
of time to take Europe back to the Little Ice Age. What enormous energy
and
dust cover released by the Krakatoa over a period of three years could
not
achieve, namely a significant modification of regional or global
weather,
occurred in Europe, out of the blue, within quarter of a year after the
war had
started. European winters turned from mild to arctic. Each of the
triple war
winters (1939-42) is discussed elsewhere in detail. (Baltic Sea
cooling, 2_17), and
Arctic by occupation, 3_11),
and Cold axis 1941/42 (3_22).
Two
‘war at sea’ phases during WWII
A further strong
indication of the enormous
impact the 2nd
World War (WWII) had on weather modification and
climate change can be found if one reviews the first three war years,
and their
corresponding winters of 1939/40, 1940/41 and 1941/42, as a
‘package’.
For two and a
half years, from September
1939 until spring 1942, the war at sea had been largely confined to
Europe’s
seas or close-by waters. Most of the military activities took place in
the
Baltic Sea, the North Sea, the Eastern part of the North Atlantic and
the
Mediterranean Sea. This changed completely within a few months after
Japan’s
attack on Pearl Harbour on December 7th, 1941, and the United States
joining
the Allies as a party in war against Japan and Germany. The picture of
the war
at sea changed dramatically, when it became global and entire areas of
the
North Atlantic and North Pacific became major battlegrounds. The war
machinery
increased to dimensions anyone could have hardly imagined prior to
Pearl
Harbour event. The global war at sea from 1942 to 1945 is discussed in
chapters: “ Oceans at war” (4_11),
and Ocean system effected (4_12). The
focus of attention in the following is on the time period when the war
at
sea was mainly confined to European waters.
Climatic
relevance of the two phases
Before looking at
the European ‘three war
winter package’, brief considerations should be given to the
presumed relevance
or difference that each phase may have had a role on the significant
climate
change that started with the winter of 1939/40. So far it is widely
accepted
that global temperatures reflect a significant cold phase from 1940
until end
of the 1970’s. Immediate impression that this trend was
caused by only one
event may lead to a wrong conclusion. War at sea from 1939-45 had two
distinct
periods: the regional war at sea in Europe (1939-42), and the global
war at sea
(1942-45).
With regard to
ocean structures and
dynamics, a war at sea confined to European waters is an event that
differs
from the turmoil caused by ‘stirring and mixing’ of
entire ocean areas for more
than three years continuously. Actually since 1942, all seas in the
Northern
Hemisphere, from Murmansk to Florida and from the Bering Sea to Manila,
had
been ‘ploughed through’ in combat by many thousands
of ships, torpedoes, bombs,
depth charges and sea mines.
The most obvious
practical impact of the
extended war at sea since 1942 was that the global war at sea impeded
further
severe war winters in Europe. This does not mean that the
‘war impact’ on Northern
European waters had been diminished, but that the global seawater
‘stir and
mix’ effect superseded the regional impact (e.g. to early
cooling of regional
sea water).
From a logical
point of view, one might
expect that if all military activities had been stopped in December
1941, the
climate would have quickly recovered to pre-war conditions. In this
case, the
three severe war winters from 1939-42 could have been regarded as
‘modified’ by
the war at sea
However, as
recent precedents to the 1939/42
events indicate that logic would lead to a wrong conclusion. As will be
shown
in another paper on ‘seaclimate.com’, specific
warming in the Northern Atlantic
realm in the 1920’s and 1930’s had most likely been
caused by the war at sea
during 1st World War (WWI), (Spitsbergen heats up (5_12). Insofar,
one
could expect the 1920’s-1930’s warming trend to
continue, if not to increase.
As the war at sea
had not been terminated
in December 1942 but went global instead, the trend changed to cooling,
thus
indicating that it makes sense to clearly distinguish between pre and
post
Pearl Harbour with regard to weather modifications and climatic
changes.
War and the
seasons
The relevance of
annual seasons and
geographical regions has been repeatedly emphasised in other papers.
Making any
distinction is to select those periods most suitable for climate change
research. In Northern Europe there are seasons when the daily influence
of the
sun is reduced and is thus weak. During winter the ocean and seas
become the most
direct, if not the sole ‘weather generator’. Impact
of the war machinery on sea
is easier to trace in the absence of the otherwise dominating climatic
factor,
the sun.
In summer a war
at sea will generate the
same ‘alterations’ to the hydro-dynamics of the
seas (although sometimes with
totally different consequences), but it will be much more difficult to
identify
changes in the behaviour of the weather, though the relevance is
obvious. From
the moment the sun is in a position to warm the sea surface, any
‘stirring and
mixing’ by military activities will force the warm surface
water into depths.
Once energy is stored in water, it will remain there for quite a while.
Even
this process may show a climatic effect during the summer season, as
briefly
explained in the next section.
Three war
summers 1939-1942
In countries
close to the North Sea and
Baltic Sea, the three war summers were generally regarded as fine,
sunny and
dry. After cold winters, this has not happened for the first time. The
cold
water of the seas gives the area a more continental impact with more
sun and
subsequently more warm and summery weather. By war-at-sea-activities
the period
of cold surface water may have been prolonged, and thus extended the
continental weather period beyond normal.
Centres of
record winters
It is interesting
to observe that certain
regions report record climatic events on one hand and on the other hand
had
seen intensive military activities ‘close by’.
- 1939/40:
Germany reported a record
cold winter. In fact heavy mining, fighting (e.g. Gdansk), military
surveillance, transport and exercises took place in coastal waters of
the
Baltic Sea during pre-winter months. (Winter 1939/40, 2_11)
- 1940/41:
Norway claimed to have
recorded low temperatures as never measured before at a number of
stations in
southern Norway immediately after the Germans invaded Norway in the
summer, and
mine warfare and fighting continued along its coast and heavy ship
movements
took place between Germany and Norway thereafter. (Arctic by
occupation, 3_11)
- 1941/42: Sweden and Stockholm claimed
the coldest winter in more than 130 years; after the German invasion of
Russia
codenamed ‘Barbarossa’, brought heavy fighting to
the Baltic countries from
June to December. (Stockholm’s record, 3_23)
The centre of the
cold was ‘in the middle
of the Baltic and North Sea’ somewhere between Hamburg and
Skagens. Not only
Sweden claimed the third winter of 1941/42 as the coldest, but also
Denmark
(Lit.: Det Danske)[2]
and The Netherlands (Lit.: Labrijn)[3],
leaving the first war winter 1939/40 ‘only’ a
second place.
Scientists’
observation of war winters 1939-1942
The occurrence of
three very severe winters
in succession during WWII, can be regarded as a major evidence to prove
that
this was not a natural variation, but was caused by massive military
activities
in Northern European waters. Before discussing this matter further, the
exceptionality of these winters shall be discussed with reference to
remarks of
scientists, who are ‘time witnesses’ and whose work
had been published already
during WWII, or soon after these remarkable winters.
Drummond 1943
– Kew Observatory
Drummond
(Lit.: Drummond)[4]
started his essay on data from Kew Observatory with the following text:
“The
present century has been marked by such a widespread tendency towards
mild
winters that the ‘old-fashioned winters’, of which
one had heard so much,
seemed to have gone for ever. The sudden arrival at the end of 1939 of
what was
to be beginning of a series of cold winters was therefore all the more
surprising. Never since the winters of 1878/79, 1879/80 and 1880/81
have there
been in succession three so severe winters as those of 1939/40, 1940/41
and
1941/42.” He further points to another
significant aspect with regard to the theme of this investigation:
“Since
comparable records began in 1871, the only other three successive
winters as
snowy as the recent ones were those during the last war, namely
1915/16,
1916/17 and 1917/18, when snow fell on 23%, 48% and 23%, of the days,
respectively”.
Drummond’s table showing percentage of days of snowfall is as
follows:
| Year |
December |
January |
February |
Dec.- Feb. |
| 1939 -40 |
6 |
32 |
24 |
21 |
| 1940-41 |
6 |
36 |
29 |
23 |
| 1941 -42 |
3 |
42 |
46 |
30 |
| Average
(1871 – 1938) |
6 |
10 |
11 |
9 |
Comment: Snow
issue is a marvellous piece
of evidence to link war at sea and weather modification. With regard to
the
intensity of snow, see: Rain-Making (2_31); with
regard to World War I,
see: Europe weather 1914-18 (5_11).
Lewis 1943
– British Isles
Lewis (Lit.:
Lewis)[5]
made the following two statements concerning snow-cover in the British
Isles in
January and February of the severe winters of 1940, 1941 and 1942:
“The
three consecutive winters of 1940,
1941 and 1942 were, however, unusually severe; the snow was
considerable and
the number of day of snow-laying comparatively large.”
“Three
such severe winters in succession as
1940, 1941 and 1942 appear to be without precedent in the British Isles
for at
least 60 years, a similar succession occurring from
1879-1881.”
Liljequist 1943
– Stockholm
Liljequist (Lit.:
Liljequist, Stockholm)[6]
writes: Very cold winters in Sweden
occur as a rule under circumstances when the atmospheric circulation is
weakly
developed, but they are sometimes intensified due to eruptions of cold
air from
the Arctic. Three consecutive cold winters are scarce. During the
period
1757-1942 only three such cases occurred (means temperature of December
– March
lower than minus 5° C); for which the figures are as follows:
Stockholm, 1757
– 1942,
| 1783/84 –6.0° |
1802/03 –5.1° |
1939/40 –6.2° |
| 1784/85
–5.4° |
1803/04
–6.0° |
1940/41
–5.3° |
| 1785/86
–5.5° |
1804/05
–6.0° |
1941/42
–7.5° |
| Mean
–5.6° |
Mean
–5.7° |
Means
–6.3° |
Comment:
The result is remarkable. Not only is 1939-42 clearly the coldest group
of
three winters, but also the difference to the next coldest group is
astonishing. While the difference between the other two record groups
is 0.1 C°
the difference between 1802-05 and 1939-42 is 0.6° C.
Liljequist
summarizes his results on
Stockholm’s cold winters from 1757-1942 as follows (excerpt):
Since the
beginning of temperature observations from about 1760 up to the decade
1931-1940 mean temperatures of the winter has increased by about
2° C. This
tendency is especially marked from the middle of the 19th
century.
Number of severe winters has decreased in recent years, while mild
winters have
remained rather constant in number.
Liljequist
concludes his summary (excerpt):
Remarkable change in the winter climate came to an abrupt end in 1940,
with
three severe winters 1940, 1941 and 1942. It is noticeable that one of
the very
mildest series of three winters, viz. 1938-1939 preceded the most
severe ones,
1940-1942.
Comment:
War at sea in general, and cold winters of 1939/40 and 1941/42 in
particular,
the extensive fighting in the Baltic Sea and the Gulf of Finland
provide the
only plausible explanation for the severity of the war winters of
1939-42 in
Sweden.
Hesselberg and
Birkeland 1956 - Norway
Authors
(Lit.: Hesselberg)[7]
give a number of information on the particular speciality of the three
war
winters. With regard to the most exceptional winter of 1940/41 in
respect of
Norway, the winter that followed German occupation of the country in
summer
1940 is outlined in greater detail in: Arctic by occupation (3_11).
Most
remarkable is the fact that only South Norway actually experienced
three severe
winters due to their closeness to the North and Baltic Sea which was
one of the
main areas of war at sea activity. According to the authors, who
provide only
departure figures from the corresponding mean values for the period
1901-30,
some figures concerning Southern Norway (in approximation) are given as
follows:
The
meansdeviationsfor the Period 1940-42 from the mean values for the
period
1901-30
Approximate
figures for Southern Norway (Source: Hesselberg)
| |
Winter |
Spring |
Summer |
Autumn |
| Atmospheric
pressure |
+6 mbar |
+3 mbar |
+0,5 mbar |
+0,5 mbar |
| Air
temperature |
-4°C |
-1°C |
+0,3°C |
+0,2°C |
| Amount of
precipitation |
- 12% |
- 8% |
+2% |
+3% |
| Wind from
the north |
+24% |
+8% |
+4% |
+7% |
| Wind from
the east |
-5% |
0 |
0 |
-2% |
| Wind from
the south |
-17% |
-10% |
-6% |
-9% |
| Wind from
the west |
-1% |
+2% |
+2% |
+4% |
Comment:
Change in wind directions from the south to the north is quite
remarkable. It
indicates an enormous flow of air towards the North Sea and the Baltic
Sea, main
areas of military activities at sea since 1939, until the war at sea
went
global in 1942.
Rodewald 1948
– Severe Winters
Rodewald (Lit.:
Rodewald), Winter I)[8],
expressed his surprise at the arrival of three cold winters, in
particular,
that they came so suddenly, and contrary to the principle of conversion
of the
circulation and temperature deviation. Rodewald (Lit.:
Rodewald, Winter II) [9]
points to the air pressure aspects in the Atlantic during the months
preceding
the winters (1939-42) as follows:
- From October
to November a huge area
of low depression covers most of Europe. The centre with
–11mb (from mean
value) is stationed between Norway and Shetland (entrance to the North
Sea),
which is south of Iceland.
Comment: Movement of the centre to the
east has most likely been caused by the military activities in
Europe’s
northern seas; whereby increased evaporation would be reflected in
lower air
pressure.
- December shows
an inverse picture.
Europe is dominated by a pressure increase of +12mb (from mean value)
with the
centre west of the Hebrides.
Comment: During the three Decembers
(1939-42) the seas in Northern Europe are no longer able to sustain
(the usual)
maritime conditions. Due to ‘stir and mix’ effect,
they are too cold and
therefore will soon be subjected to continental (high air pressure)
influence.
According to
Rodewald the positive anomaly
in December would, by rushing to Northwest Europe in January, actually
generate
strong Mid European winters. He includes in his investigation two other
cold
winters during the first half of the 20th
century, viz. the winters
of 1928/29 and 1946/47, (Extreme winter 1946-47,
4_21). An
interesting
question as to why those winters remained solitary while the winters of
1939-42
came in succession, will be answered only with regard to the
latter. As the war at sea during these winters was
particularly a war in the North Sea and Baltic Sea, it can be regarded
as an
evidential indication of a link between the war and the war winters of
1939-42.
Three ice
winters in the Baltic Sea
A brilliant
indicator of the severity of a
winter in Baltic Sea and its bordering countries is the annual feature
of
icing. With the extent and severity of ice during the three war winters
of
1939-42 it should be possible to provide ample proof that this
extraordinary
situation could only have been generated by intensive military use of
these
waters over the time period in question. Reference is made to numerous
papers
and explanations elsewhere, Baltic Sea cooling; 1939-40 (2_17), and
Arctic by occupation; 1940-41 (3_11),
and Baltic Sea icing; 1941-42 (3_24).
However, main aspects are summarised as
follows:
- First and
foremost there is the
suddenness and severity of each of these ice winters for which no other
cause
could be attributed than the war at sea.
- It is possible
to establish a direct
link between the extent of activities in the Baltic Sea and the degree
of icing
and arctic winter conditions:
- 1939/40
intensive military activities,
Gdansk, mining western Baltic and Gulf of Finland, Finnish-Russian war
at sea,
resulted in very heavy ice.
- 1940/41 there
were only general naval
activities and as such icing was less serious compared to previous
year, but
nevertheless it was a severe ice winter.
- 1941/42
Germans invaded Russia and had
been fighting with the Russian Baltic Fleet for five months during
June-December 1941 in the Central and the Northern Baltic Sea;
resulting in the
most extended and heavy icing ever observed.
Another proof of
great importance is the
fact that there has never been such a severe icing. It should be noted
that
over the observation period the general mean temperatures in Sweden,
and in the
Northern Hemisphere rose roughly one degree, while the winter
temperatures in
Stockholm had risen about 2°C since 1761 (Lit.: Liljequist,
Stockholm)[10].
This comparison of extreme winter situations from the late 18th,
or
early 19th
century to similar events in mid 20th
century,
will make the latter appear even more severe and extraordinary.
As already
indicated above, Liljequist
(Lit.: Liljequist, Is 1941/42)[11]
observed: Three ice winters in succession are very rare. During almost
200
years of weather observations at Stockholm, there are only two periods
that
came close to the most recent one in 1939-42. But none of the previous
‘three-winter-periods’ had been as cold as the
latter, which was 0.6°C colder
than the next group:
Mean value
December -March
| 1783-86; means: -5.6°C |
1802-05; means: - 5.7°C |
1939-42; means: -6.3°C |
A further piece
of hard evidence that nothing
but the war at sea had turned the Baltic Sea into an ice age like
status is the
extent of ice cover during the three years in question. According to a
graph by
the Finnish Institute (Lit.: Finnish Inst.)[12],
showing the ice cover in the Baltic Sea, north of latitude 57°
North, there has
not been one group of three successive years with so much ice cover
since 1720,
as during the three war years 1939-1942. As the graph provided by the
Finnish
Institute actually shows figures only since 1720, the ice cover during
the
winters of 1939-42 could have been the most extensive in many hundred
years.
From the whole period of more than 200 years, only 15 winters reached
the
highest possible ice volume, including those of 1939/40 and
1941/42. One of the reasons for this rarity of
successive high ice coverage is presumably the fact that, from the
moment the
Baltic Sea reaches a high ice cover, the water body no longer transfers
heat to
the atmosphere; the deeper waters retaining more heat for the following
winter
season. But due to the intensive ‘stirring and
mixing’ of the sea by military
activities, a record ice coverage in the Baltic Sea during the three
war years
1939-42 had been achieved, which actually was inevitable. There is
virtually no
other explanation available.
Europe, the
unique receiver of three arctic winters;
Europe - the sole
generator of the arctic winters.
It is worth
noting that only Europe
experienced the three arctic winters during 1939-42. North America and
Asia did
not go through the same experience. Unique situation concerning the
cold
January 1940 all over the Northern Hemisphere has been addressed in:
Rain-making (2_32) together
with USA dried out 1939 (2_32)
and
War in China (2_33). From
this follows that the principal source for
generating and supporting the arctic winters in Europe, must have
originated in
Europe. External forces can be excluded with certainty. There is hardly
any
imaginable influence, which would have been able to introduce three
‘Little Ice
Age winters’ only to North Europe while sparing other regions
on the Northern
Hemisphere.
The British
Isles Great War ‘three years winter package’
1915-1918
Close similarity
between the three war
winters of 1939-42 and 1915-18 is the best evidence on the relevance of
climatic changes by the war at sea. As already mentioned (Lit.:
Drummond)[13],
both periods saw excessive snow during three war years. In the chapter:
Europe
weather WWI (5_11) it
is argued that the winter months of 1915-18 were
almost as cold as during the period of 1939-42. The war at sea all
around
Britain, (War at sea WWI, 5_13),
and Sea mines WWI (5_14), leaves
no option but to accept this as evidence of anthropogenic climatic
changes.
Summary
Quite a number of
indications provide
sufficient evidence that a succession of three arctic winters, like
those of
1939-42, have their origin in the impact of the war machinery on the
natural
environment. Without even going into too much technical explanation on
the
‘stirring and mixing’ of the seas and resulting
consequences, the sheer fact of
the sudden occurrence of three arctic winters ‘from
nowhere’, shows sufficient
proof that mere ‘natural variation’ can be
definitely excluded as a cause of
the extraordinary weather conditions during the winters of 1939-42. The
three extreme
winters 1939 –1942 in succession is an impeccable example of
anthropogenic
climatic change.
There was nothing
in orbit, in the skies or
on earth that could have triggered extraordinarily cold winters for
Northern
Europe alone. There was nothing but the war at sea.
LITERATURE:
Det Danske
Metorologiske
Institut; ‘Is- og besejlingsforholdene I de danske Farvande
in Vinteren
1941-42; Kobenhavn, p.14.
Drummond, A.J.;
‚Cold winters at Kew
Observatory, 1783-1942’; Quarterly Journal of Royal Met.
Soc., No. 69, 1943, pp
17-32.
Finnish Institute
of Marine Research;
M.Leppäranta et.al; “Phases of the ice season in the
Baltic Sea’ No. 254,
Suppl.2; Helsinki 1988
Hesselberg, TH.,
and Birkeland, B.J.; ‘The
continuation of the secular variations of the climate of Norway
1940-40’, in:
Geofysike publikasjoner Vol. XV. No.5. , Bergen 1944-56; pp. 3-40.
Labrijn, Ir.A.;
Ijswinters in Nederlands
voor het Tijvak 1706 –1946; in Holland Geographic Soc.; 1946
(47?), p. 754-763.
Lewis, Lilian,
F.; ‘Snow-cover in the
British Isles in January and February of the severe winters 1940, 1941
and
1942’, in: Quarterly Journal of Royal Met. Soc., 1943, pp.
215-219.
Liljequist,
Gösta H.(Stockholm); ‘The
severity of the winters at Stockholm 1757 – 1942’,
in: Geografiska Annaler 1-2,
1943, p. 81-104; and as an extended paper in: Meddelanden, Serien
Uppsatser,
Stockholm 1943, pp.1-24.
Liljequist,
Gösta H.(Is
1941/42); ‚Isvintern 1941/42’; in: Staten
Meteorologisk – Hydrograiska Anstalt,
No.4, 1942, pp.2-15.
Rodewald, M.
(Winter
I); ‚Das Zustandekommen der strengen
europäischen Winter’, in: Annalen der Meteorologie,
April/Mai 1948, pp 97-99.
Rodewald, M.;
(Winter II)
‚Die barischen Vorbereitungen strenger und milder
mitteleuropaeischer Winter’,
in: Annalen der Meteorologie, April/Mai 1948, pp 99-105.
Wexler, H.;
‚On the effects of volcanic dust on insulation and
weather’, in: Bulletin
American Meteorological Society, Vol. 32, No. 1, January 1951, pp.
10-15.
[1]Wexler,
H.;
‚On the effects of volcanic dust on insulation and
weather’, in: Bulletin
American Meteorological Society, Vol. 32, No. 1, January 1951, pp.
10-15.
[2]Det
Danske Metorologiske Institut; ‘Is- og
besejlingsforholdene I de danske Farvande in Vinteren 1941-42;
Kobenhavn, p.14.
[3]
Labrijn, Ir.A.; Ijswinters in Nederlands voor het Tijvak 1706
–1946; in Holland Geographic Soc.; 1946 (47?), p. 754-763.
[4]
Drummond, A.J.; ‚Cold winters at Kew Observatory,
1783-1942’;
Quarterly Journal of Royal Met. Soc., No. 69, 1943, pp 17-32.
[5]
Lewis, Lilian, F.; ‘Snow-cover in the British Isles in
January and
February of the severe winters 1940, 1941 and 1942’, in:
Quarterly Journal of
Royal Met. Soc., 1943, pp. 215-219.
[6]
Liljequist, Gösta H.; ‘The severity of the winters
at Stockholm
1757 – 1942’, in: Geografiska Annaler 1-2, 1943, p.
81-104; and as an extended
paper in: Meddelanden, Serien Uppsatser, Stockholm 1943, pp.1-24.
[7]
Hesselberg, TH., and Birkeland, B.J.; ‘The continuation of
the
secular variations of the climate of Norway 1940-40’, in:
Geofysike publikasjoner
Vol. XV. No.5. , Bergen 1944-56; pp. 3-40.
[8]
Rodewald, M. (Winter I); ‚Das Zustandekommen der
strengen
europäischen Winter’, in: Annalen der Meteorologie,
April/Mai 1948, pp 97-99.
[9]
Rodewald, M.; (Winter II) ‚Die barischen
Vorbereitungen strenger und milder mitteleuropaeischer
Winter’, in: Annalen der
Meteorologie, April/Mai 1948, pp 99-105.
[10]Liljequist,
Stockholm, FN 6
[11]Liljequist,
Gösta H.(Is
1941/42); ‚Isvintern 1941/42’; in: Staten
Meteorologisk – Hydrograiska Anstalt,
No.4, 1942, pp.2-15.
[12]
Finnish Institute of Marine Research; M.Leppäranta et.al;
“Phases
of the ice season in the Baltic Sea’ No. 254, Suppl.2;
Helsinki 1988
|