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Solar Minima, Earth's rotation and Little Ice Ages in the past and in the future: The North Atlantic–European case


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The past Solar Minima were linked to a general speeding up of the Earth's rate of rotation. This affected the surface currents and southward penetration of Arctic water in the North Atlantic causing “Little Ice Ages” over northwestern Europe. At around 2040–2050 we will be in a new major Solar Minimum. It is to be expected that we will then have a new “Little Ice Age” over the Arctic and NW Europe. The mechanism proposed for the linkage of Solar activity with Earth's rotation is the interaction of Solar Wind with the Earth's magnetosphere; the decrease in Solar Wind at sunspot minima weakens the interaction with the magnetosphere that allows the Earth to speed up, and the increase in Solar Wind at sunspot maxima strengthens the interaction with the magnetosphere that slows down the spinning of the Earth.
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Solar Minima, Earth's rotation and Little Ice Ages in the past and in the future
The North AtlanticEuropean case
Nils-Axel Mörner
Paleogeophysics & Geodynamics, Stockholm, Sweden
abstractarticle info
Article history:
Accepted 13 December 2009
Available online 25 January 2010
Solar Minima
Rotational deceleration
Solar Wind
Little Ice Ages
The Gulf Stream
The Future
The past Solar Minima were linked to a general speeding up of the Earth's rate of rotation. This affected the
surface currents and southward penetration of Arctic water in the North Atlantic causing Little Ice Ages
over northwestern Europe. At around 20402050 we will be in a new major Solar Minimum. It is to be
expected that we will then have a new Little Ice Ageover the Arctic and NW Europe. The mechanism
proposed for the linkage of Solar activity with Earth's rotation is the interaction of Solar Wind with the
Earth's magnetosphere; the decrease in Solar Wind at sunspot minima weakens the interaction with the
magnetosphere that allows the Earth to speed up, and the increase in Solar Wind at sunspot maxima
strengthens the interaction with the magnetosphere that slows down the spinning of the Earth.
© 2010 Elsevier B.V. All rights reserved.
1. Introduction
The concept of geoid changes (Mörner, 1976) seemed to imply
that there would hardly be any order in the eustatic differentiation
over the globe. Despite this, I observed that there were some
regularities, viz. correlation and anti-correlation between certain
regions. Furthermore, those regions were strongly affected by ocean
surface currents. The Kuro Siwo Current and the Gulf Stream seemed
to beat in pace, and the Equatorial Current seemed to record an East
West beat. This could, in my opinion, only be understood in terms of a
feedback interchange of angular momentum between the oceanic
surface currents and the solid Earth (Mörner, 1984, 1987, 1988, 1990,
1992, 1993). The Gulf Stream seemed to exhibit 16 major pulses or
beat within the Holocene (Mörner, 1984). In the climaticeustatic
cyclicity diagram of Mörner (1973) there are 23 Holocene pulses
recording frequency-changes pulses ordered in three larger waves
tting well with oceanic circulation pulses (Mörner, 1995a). The
concept is further analysed elsewhere (Mörner, 1995b, 1996a, 1996b,
2005). In this paper I will address the question of Solar Minima in
the last 600 years and the next one to be expected at around 2040
2. Major frames and boundary conditions
Mass, energy and momentum what I called the holy trinityin
terrestrial and planetary physics (Mörner, 1995b, 1996a)are
usually all considered as constant. This is illustrated in Fig. 1 with
respect to our terrestrial situation. Earth's energy could be altered by
changes in Solar irradiance (Fig. 1, right). Despite the fact that the
variation during a sunspot cycle is small (e.g. Foukal and Lean, 1990;
Willson, 1997; Pap and Fröhlich, 1999), hypothetical larger Solar
irradiance variations on the decadal-to-centennial time scale have
been proposed in order to explain the terrestrial climatic changes
during the last centuries to millennium (e.g. Hoyt and Schatten, 1993;
Lean et al., 1995; Lean and Rind, 1999; Bard et al., 2000; Rind, 2002).
The present theory (Fig. 1, middle) implies an alternative explanation
to the solarterrestrial linkage on a decadal-to-centennial basis.
We may changemass, energy and momentum, however, by
redistribution of relevant factors within the given constantter-
restrial frames (Fig. 1, middle). For example; glacial mass redistribu-
tion (e.g. Ice Ages) generates changes in sea level, which in its turn
affects Earth's rate of rotation leading to redistribution of mass (air
and water) and energy (stored in oceans and transferred by winds).
As demonstrated before (Mörner, 1984, 1987, 1988, 1995b, 1996a)
this system seems to play a dominant role for the decadal-to-
centennial changes (what we may call Super-ENSO events).
The magnetospheremagnetopause represent the interaction
between the heliomagnetic eld and the terrestrial eld, both of
which vary with time (Mörner, 1984,Fig. 2). The Solar Wind of the
heliomagnetic eld is known to vary signicantly with the sunspot
cycle. These variations affect the shielding capacity of the Earth's
magnetic eld; when weaker more cosmic ray particles pass
increasing the
C production, when stronger less particles pass
decreasing the
C production (like the in-fall of
Be). This was
known since long (cf. Stuiver and Quay, 1980). The novel thing is that
it may also change the Earth's rate of rotation by causing a number of
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terrestrial variables to change accordingly (Mörner, 1996a). This will
be further examined in this paper.
3. Solar variability
The 11-year sunspot cycle and its longer cycles are well known
phenomena. The search for those cycles in terrestrial variables has a
long and intense history, which lies beyond the scope of this paper,
however (e.g. Lean et al., 1995; Willson, 1997; White et al., 1997; Bard
et al., 2000; Rind, 2002). For the last 150 years, there seems to be a
good correlation between changes in the length of the sunspot cycle
and general changes in global mean temperature (Friis-Christensen
and Lassen, 1991), and for the last 250 years between a combined
solar irradiance modeland the mean Northern Hemisphere changes
in climate (Hoyt and Schatten, 1993).
On the centennial basis, the Solar activity (instrumental, observa-
tion, aurora, aa-index,
C production, and
Be in-fall) exhibits cyclic
variations between Solar Maxima and Solar Minima (e.g. Stuiver and
Quay, 1980; Hoyt and Schatten, 1993; Lean et al., 1995; Cliver et al.,
1998; Lean and Rind, 1999; Bard et al., 2000; Bond et al., 2001). The
Solar Minima the Dalton Minimum 18001820, the Maunder
Minimum 16451705, the Spörer Minimum 14201500 and the Wolf
Minimum 12901350 have attracted special attention because they
have been proposed to correlate (e.g. Eddy, 1976) with cold periods or
Little Ice Ages (Lamb, 1979). In the west European records (Guiot,
1992), there are quite clear cold minima at 14401460, 16871703
and 18081821 (Mörner, 1996a), i.e. right within the last three Solar
Minima. Below, I will expand on this.
4. Earth's rotation
The Earth's spin rate (angular momentum) varies on the long-term
basis as well as on the short-term basis. It is usually measured and
expressed in changes in the length of the day (LOD). Changes in the
total angular momentum (like deceleration due to tidal friction) are
compensated within the EarthMoon system (e.g. Marsden and
Cameron, 1966). Differential changes, on the other hand, imply the
interchange of angular momentum between the different layers and
sub-layers of Planet Earth (Mörner, 1984, 1987, 1996a); viz. between
the atmosphere and the solid Earth (e.g. Barnes et al., 1983; Rosen and
Salstein, 1983; Hide and Dickey, 1990; Rosen and Salstein, 2000;
Abarca del Rio et al., 2003), between the hydrosphere and the solid
Earth (Mörner, 1988, 1990), between the core and the mantle (e.g.
Rochester, 1984; LeMoûel et al., 1986) and between the inner core
and the outer core plus mantle (e.g. Mörner, 1991).
Changes in the Earth's rate of rotation due to Solar Wind changes is
a novel concept (Mörner, 1995b, 1996a; Gu, 1998) analysed in this
paper. It should be noted, however, that a correlation between
sunspot activity and Earth's rotation had been noted before (e.g.
Kalinin and Kiselev, 1976; Golovkov, 1983) as well as more recently
(e.g. Rosen and Salstein, 2000; Abarca del Rio et al., 2003). Fig. 2 gives
a plot of LOD vs. sunspot number for the period 18311995. There is a
Fig. 1. Left: The holy trinityin terrestrial and planetary physics, all regarded to be constant, hence giving the frames within which our theories and interpretations must be kept.
Middle: The dynamically effective terrestrial system and the interaction between actual changes in the distribution of mass, angular momentum and energy. Right: Changes in energy
from variations in Solar radiation, an explanation, may be possible, but no longer necessary for the understanding of the decadal-to-centennial changes in climate (cf. Fig. 13).
Fig. 2. Instrumental LOD data plotted against sunspot numbers for the period 18311995 substantiating the existence of a correlation between Solar activity and Earth's rotation
(though the LOD data are, in fact, affected by multiple different factors).
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correlation, despite the fact that LOD represents the integrated effect
of multiple affecting parameters.
5. The Gulf Stream beat
The Gulf Stream is a remarkable system bringing hot equatorial
water to higher latitudes. It implies the redistribution of mass
(affecting Earth's rotation as recorded in sea level changes) and
energy (as recorded in regional climate).
In the central North Atlantic, the Gulf Stream (North Atlantic
Current) splits into individual branches (Fig. 3); the main NE-branch
(the North Atlantic Drift with Irminger Current, branches into the
North Sea and the NorwegianN. Cape Currents), an E-branch towards
the Bay of Biscay and another major E-branch (the Azores and
Canaries Currents) towards Gibraltar and S-wards back to the
equatorial region. The distribution of water masses along the different
branches varies with time. When more water goes to the NE, less goes
to the East, and when more water goes to the East, less goes to the NE.
This mechanism was proposed 20 years ago (Mörner, 1984), later
improved (Mörner, 1988, 1995b, 1996a) and is in this paper shown
also to apply for the changes between Solar Maxima and Minima.
Kerr (2000) talks about a slow, multidecadal climate pulse that
beats the Atlantic Ocean(his AMO) and notes that already Bjerknes
(1964) talked about a surge of warm water up the Gulf Streamin
order to explain the early 20-century's warm climate over Northwest
Europe. Similarly, the North Atlantic changes recorded by Levitus
(1990) had to be related to changes in the strength of the Gulf Stream
(Greatbatch et al., 1991; Kushnir, 1994; Häkkinen, 1999). Further-
more, the major shifts in climate and sea level recorded over the last
150 years in Northwest Europe correspond with the major shifts in
LOD (Mörner, 1988, 1995b), indicating an interaction between
rotation and Gulf Stream beat on the decadal time scale. Recently,
Lund et al. (2006) have shown that, in the Florida Straits, the water
masses transported by the Gulf Stream have varied signicantly
through the last millennium with a general lowering of about 3 Sv (i.e.
) during the Little Ice Age; in their chronology dated
at about 770150 years BP. Signicantly, actual short-term variations
in the Gulf Stream transport have also been measured by sea level
variations along the east coast of United States (Ezer, 2001). What I
am here discussing, is a similar decadal-to-centennial beat in the Gulf
Stream transport and distribution of water masses (northeastward or
eastward; Fig. 3) also recorded in the spatial variance in Holocene sea
level changes (Mörner, 1984). Therefore, it seems signicant that van
der Schrier et al. (2002), when extending the sea level analysis over
the last millennium, found agreements between the changes in steric
sea level and Solar irradiance. On the decadal-to-century basis, it is
not only steric changes, but rather changes in water volume due to the
differential distribution of the water masses along the different
branches of the Gulf Stream system (Fig. 3;Mörner, 1984).
Also the changes in the ice edge position in the Nordic Seas (e.g.
Divine and Dick, 2006) and polar front migrations may be seen as a
function of these changes. The shifts in sailing routes to Greenland are
an indication of this (Pettersson, 1913; Mörner, 1995b,Fig. 4).
6. Climatic changes: NS along West Europe
The St. Jérôm database (nowadays known as the European Pollen
Data Bank, EPDB) of annual climatic changes over the last 900 years in
a grid of every 10° Long. and 5° Lat. (Guiot, 1992) was kindly put at my
disposal. The database is built on pollen records from land and sea
cores. The conversion into temperature is achieved by the transfer
function methodology of Peyron et al. (1998, 2006; cf. Guiot, 1990)
implying that the values obtained are not true temperature values but
relative average values with error bars. The temperature values are
given in centigrade above and below a local mean. Consequently, the
individual temperature records used here are relative. Therefore, no
absolute values are given in Figs. 47. In this study, however, I am not
using the individual values, but their temporal and spatial distribution
over northwestern Europe at selected grid-points.
Fig. 3. The Gulf Stream and its sub-branches, viz. the main branch to the NE (NB), the side-branch towards the Bay of Biscay (NB 1) and the main southern branch (SB) with a sub-
branch towards southern Iberia, Gibraltar and northern Africa (SB 1). Any irregularities (or beat) in the transport of water masses along the Gulf Stream system will affect rotation.
Similarly, changes in rotation will affect the distribution of water masses along the various branches (cf. Fig. 11).
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For this study, I selected 8 grip-point stations consisting of an EW
prole along Lat. 55° N at (1) 20° E, at (2) 10° E and at (3) 0°, and a
main NS prole from the North Sea down to the Gibraltar region
consisting of stations at (3) 0° Long and 55° Lat., at (4) 0° Long and 50°
Lat., at (5) 10° W Long and 45° Lat., at (6) 10° W Long. and 40° Lat., at
(7) 10° W Long. and 35° Lat., and at (8) 0° Long. and 35° Lat. (Fig. 8).
In this paper, I conne the analysis to the periods of the last three
Solar Minima with short comparative analysis of the period of the so-
called Medieval Optimum and the 20th century. The periods will be
discussed below in chronological order.
Fig. 5. Period 10701300 with the mean trend plotted of stations 3, 6 and 8. The records
show (in relative temperature) a clear anti-correlation between the North (stations 3
and 6) and the South (station 8). Period 10701150 was warm in the South and cold in
the North. A rapid transition occurred in the period 11501200. Period 12001290 was
warm in the North and cold in the South. This period corresponds to the so-called
Medieval Warm Optimum.
Fig. 4. The eight stations in the St. Jérôm (EPDB) database selected for the present analysis of temporal and spatial changes in the distribution of warmer and colder areas (i.e. relative
temperature). The stations are marked with black dots and numbers. Temperature is given in centigrade; it refers to the local mean of the station and is relative. Black squares refer to
the core sites of Bond et al. (1997) and of Bianchi and McCave (1999), here labelled B1, B2 and BM3, respectively.
Fig. 6. Period 14281464 with temperature curves for all eight stations. Vertical scale
gives relative temperature of 1 °C above and below local mean. There is a strong cooling
event 14401456 with its maximum in the North Sea (station 3). Cold water penetrated
all the way down to station 6, even reaching station 7 at the later part of the period. In
the South there was a warming, at least up to 1448. This period coincides with the
Spörer Minimum.
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6.1. AD 10701300 and The Medieval Optimum
The Medieval Optimum was coined by Lamb (1979), dated at
around AD 1250 and likely to correlate with the Solar Maximum at
about 11001250 in the Solar irradiance curve of Bard et al. (2000).
Much discussion has been devoted to this period both locally and
globally. In this paper, I conne myself to a short analysis of the
situation as recorded in the St. Jérôm database. Fig. 5 shows the
variations in mean temperature for three grid-points. It reveals that
the temperature changes do not agree in NS direction. The Medieval
Warm Optimum may be recorded in a temperature rise in the 13th
century in the North (stations 6 and 3), whilst at the same time
there was a temperature drop in the South (station 8). In the period
10701150, the situation was the reversed; warm at station 8 and cold
(a Little Ice Age) at stations 3 and 6. This NS anti-correlation is
6.2. AD 14281464 and the Spörer Minimum
Analysing the data for the 15th century, it was easy to see that
there was a drastic climatic change in Europe in the middle of the 15th
century. In Fig. 6, the records of the period 14281464 are plotted for
the 8 stations studied. In the years 1440 to 19561460 there is a major
climatic event. Cold conditions spread from the North all the way
down to station 6. The period is three-parted; (1) in years 14401444,
there was a cooling in the North (stations 16) with a warming in the
South (stations 78), (2) in the years 14451448, there was a warm
pulse from the South to the North, and (3) in the years 14491456
there was strong cold pulse reaching all the way down to station 7
(maybe, even 8) with a continuation up to 1460 in stations 57. The
northern cooling is a Little Ice Age. It correlates well with the same
event of Lamb (1979) dated at about 14301460, and the Solar
Minimum at 14401460 in the Solar irradiance curve of Bard et al.
(2000). The simultaneous warm peak (we may call it a Little
Interglacial) in the Gibraltar and North African region in years 1436
1444 gives evidence of the character of the climatic change in Europe;
viz. not general but opposed regional.
6.3. AD 16721708 and the Maunder Minimum
The 17th century is especially interesting because it is the time of
the famous Maunder Minimum and the main Little Ice Age. In the
data set, there is a very clear and obvious signal within the period
16761704 (Mörner, 1995b). Fig. 7 gives the records from the
8 stations from 1672 to 1798. In 1676 a warming begins in stations
58. From 1677 to 1679, there is a short cooling event in the North
with a clear East to West decrease. From 1687 to 1703 there is a
drastic cooling in the North. The maximum values are in the North Sea
(station 3). This ts well with Lamb's (1984) statement that the
ocean surface between Iceland and the Faeroe Islands seems to have
been about 5 °C colder. It falls within the Solar Minimum at 1660
1710 in the Solar irradiance curve of Bard et al. (2000). Obviously this
is the Little Ice Ageevent of the 17th century (Lamb, 1979). In the
South (station 7 and especially 8), there is a distinct warming event,
however. There is an initial warming phase 16761687 centred over
stations 57 and a main warming phase 16761706 conned to
stations 78 with the strongest signal at station 8. The NorthSouth
anti-correlation is striking.
6.4. AD 18001833 and the Dalton Minimum
In the early 19th century data, there is a clear signal coinciding
well with the Dalton Minimum (around 18001830 in the Solar
irradiance curve of Bard et al., 2000). Fig. 8 gives the records from the
Fig. 8. Period 18001833 with temperature curves for all eight stations. Vertical scale
gives relative temperature of 1 °C above and below local mean. A cooling event is
recorded 18081821. It represents the Little Ice Ageof the Dalton Minimum. This
time, the cooling reached all the way down to station 7, implying that even the sub-
branch towards the Gibraltar (SB 1) suffered diminishing.
Fig. 7. Period 16721708 with temperature curves for all eight stations. Vertical scale
gives relative temperature of 1 °C above and below local mean. There is a strong cooling
event at 16871703 with maximum cooling in the North Sea and with cold water
spreading all the way down to station 6. This is the cold event or Little Ice Ageof the
Maunder Minimum. In the South (stations 7 and 8), there was a warming. At 1676, a
distinct warming begins in stations 58 reaching a maximum in 16891691 in station 6
and lasting up to 1686. A short cooling is registered in the North around year 1677.
Obviously more hot water was now owing along the sub-branch towards the Bay of
Biscay. The anti-correlation between the Little Ice Ageof the North and the Little
Interglacialof the South is striking.
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8 stations for the period 1800 to 1833. A strong cooling event is
recorded in stations 17 with maximum values in the coastal sites
(stations 36) for the period 18071821. Obviously, we here have a
record of the Little Ice Ageof the 19th century. In this case, all the
sites along the coast, from station 3 down to station 7, record the
cooling event. There is no opposed warming in the south. This implies
that even the southeastern branch of the Gulf Stream (Fig. 3)
decreased giving a cooling event at station 7.
6.5. AD 19241958 and the cooling event around 1940
The general picture of temperature changes on a European as well
as global scale is that temperature rose from the Mid-19th century up
to 19301940 after which temperature fell and kept lower from about
1940 to 1970. In Fig. 9, the records of three northern stations (13) are
compared with those of two southern stations (78). The warm
optimum in the 1930s in the North corresponds to a cooling in the
South. The terrible war-winters in the North (stations 13) anti-
correlate with a warm period in the South (station 7 and, less clear, 8).
The proposed global cooling event around 1940 is here recorded as a
drastic cooling in the North at the same time as there was a
simultaneous signicant warming in the South; i.e. once again
evidence of a NS anti-correlation (also recorded in the European
Climate Assessment database by Klein Tank et al., 2002).
7. Discussion
At all the three Solar Minima, the temperature signal in Europe was
quite clear (Figs. 68); viz. a cooling event spreading, with a maximum
in the North Sea, down along the coast of Europe all the way to central
Portugal (station 6). At the same time, the South Iberian and North
African region (stations 78) experienced warming during the Spörer
and Maunder Solar Minima. This can only be understood in terms of a
shift in the main ux of the Gulf Stream (Fig. 3)andasouthward
penetration of Arctic water, or rather southward spreading of a
signicant SST cooling, as illustrated in Fig. 10 (cf. Mörner, 1995b,
1996a). The Maunder Minimum climatic event is most expressive as it
includesa stepwise displacement of the Gulf Stream from (1)a normal
northern dominance, via (2) an intermediate dominance along the
eastern branches towards the Bay of Biscay (stations 46) and Gibraltar
(stations 78), to (3) a dominance conned to the southern branch
(stations 78), and then back (4) to northern dominance again
(Fig. 10B). During the Dalton Minimum even the sub-branch towards
Gibraltar diminished Fig. 10C).
The forcing function must, in my opinion, be a speeding up of the
Earth's rate of rotation deecting the Gulf Stream to southern regions
at the same time as cold Arctic water is drawn down along the Atlantic
east coast. So far, the observational records here presented. The
excellent drift-ice records of Bond et al. (1997, 2001) seem directly to
add on to this picture, however. Cores form both sides of the North
Atlantic (off Newfoundland and off Ireland) record cyclic peaks in ice-
rafted material from drift-ice (IRD), indicating cyclic alternations
between two modes: (1) low IRD, warmer SST and a circulation as
today, and (2) ice-rafting events with peaks in IRD, colder SST and a
signicant southward advection of colder and fresher water. As a
consequence, the thermohaline circulation was reduced as recorded
in NADW by Bond et al. (1997) and in ISOW by Bianchi and McCave
(1999). This is consistent with the present model (Mörner, 1995b,
Fig. 2), where the surface water circulation affects the deep-water
circulation, not vice versa, as often claimed. Furthermore, this
southwards shift of colder, ice-bearing surface water far into the
sub-polar North Atlantic had an ocean surface circulation, which was
coupled with the atmospheric circulation over Greenland (Bond et al.,
1997). Consequently, we can safely assume that the observed cooling
events recorded far down along the European coasts (Fig. 10) also
extended over the central and western parts of the North Atlantic (as
recorded by the drift-ice events).
The correlation by Bond et al. (2001) between periods of increased
drift-ice and periods of reduced Solar activity (as recorded by
cosmogenic nuclides which, in fact, refers to Solar Wind activity)
calls for a re-examination of the Holocene Gulf Stream pulses
previously interpreted in terms of differential rotation (Mörner,
1984, 1988, 1995b), because they may represent the same mechanism
as here proposed; the Solar Wind effect on the Earth's total rate of
Fig. 11 gives four possible stages in the intensity and distribution of
the Gulf Stream and its sub-branches; viz. (1) an equal distribution in
all sub-branches, (2) a dominance along the main northern branch on
the expense of the eastern (southern) branches, (3) a dominance
along both the eastern branches on the expense of the northern
branch, and (4) a dominance restricted to the southern branch on the
expense of both the others, and with a simultaneous penetration of
Arctic water all the way to central Portugal. Stage 2 represents periods
of low rate of rotation, and stage 4 periods of high rate of rotation.
Consequently (and this is a main novel conclusion), Solar Minima
represent periods with a speeding up (acceleration) of the Earth's rate
of rotation (stage 4), whilst Solar Maxima represent periods of
slowing down (deceleration) of the Earth's rate of rotation (stage 2) as
illustrated in Fig. 12.
If this is correct, there should be a correlation between sunspot
activity and Earth's rotation. This is exactly what has been observed
(above: Section 4). Previously, the reason for this correlation
remained obscure, however.
The interpretation for this causal correlation must be searched in
the variability in the Solar Wind and its interaction with the
magnetosphere. At strong Solar Wind during Solar Maxima, the
interaction is strong leading to a strong shielding capacity (as
recorded) but also to a slowing down of the Earth's rate of rotation
(as here proposed). At Solar Minima, the Solar Wind is weak and the
interaction with the magnetosphere weak with a low shielding
capacity (as recorded) and with a speeding up of the Earth's rate of
rotation (as here proposed and demonstrated by the ocean circulation
changes at the Spörer, Maunder and Dalton Solar Minima).
8. Solar Wind and Earth's rate of rotation
Having noted that all the three major Solar Minima in the last
600 years coincided with the Gulf Stream stage 4 situation of Fig. 11,it
seemed logical as a driving force to infer a general acceleration of the
Earth's rate of rotation; in this case, not an interchange of angular
Fig. 9. Period 19241958 with temperature curves of the three northern stations (13)
and the two southern stations (78). The warm peak in the mid-30s in the northern
stations corresponds to a cold period in the southern stations. Similarly, the cold war-
years in the North correspond to a warm period in the South. The NS anti-correlation is
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momentum between the hydrosphere and the solid Earth (e.g.
Mörner, 1988), but a speeding-up of the entire Earth.
Knowing that the Solar Wind beats with a tremendous force
between Solar Maxima and Minima, varying its ow rate between 900
and 300 km s
, interacting with the Earth's magnetosphere, altering
its radius by 1 Earth radius, etc., it seemed obvious the these changes
had to affect the Earth's rate of rotation, hence explaining the
correlations observed between Solar activity and LOD on the short-
term (Fig. 2) as well as the centennial basis. A Solar Wind increase
(during a Solar Maximum) would lead to a deceleration, whilst a
decrease during a Solar Minimum would lead to an acceleration just as
inferred from the observed oceanic changes in circulation and SST,
and land surface temperature during the Spörer, Maunder and Dalton
Minima over western Europe and adjacent parts of the Atlantic.
This theory was presented at the IUGG meeting in Boulder in 1995,
at a climatic meeting in Rio (Mörner, 1996a) and more extensively at
the IUGG meeting in Birmingham (Mörner, 1999). The physical
mechanism, however, was not further explored. Krymsky (1995) had
discussed a possible mechanism of transferring impulse moment from
the Solar Wind to the magnetosphere. Later, Gu (1998) gave a detailed
account on the mechanism of transferring rotational energy from the
Solar Wind to the magnetosphere and the Earth. He proposed that this
Fig. 11. Four stages in the distribution of hot equatorial water along the Gulf Stream system: (1) equal distribution over the whole system, (2) dominant distribution along the
northern branch on the expense of the eastern (NB 1) and southern branches, (3) dominant distribution along the eastern and southern branches on the expense of the northern
branch (as was the case 16761686), and (4) dominant distribution along the southern branch on the expense of the northern branch, including the eastern sub-branch, and strong
southward penetration of cold Arctic water all the way down to station 6 (as was the case during all the three Solar Minima here analysed), not only along the eastern side of the
North Atlantic but also in the central and western parts judging from the drift-ice records of Bond et al. (1997, 2001).
Fig. 10. Ocean circulation models explaining the temperature changes observed for the Spörer Minimum (A), for the Maunder Minimum (B) and for the Dalton Minimum (C). At all
three Solar Minima, the northern branches of the Gulf Stream diminished allowing cold Arctic water to penetrate down along the coasts all the way to station 6, probably even down
to station 7 at the Dalton Minimum (cf. Fig. 11, stage 4).
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mechanism could explain the difference between the observed
deceleration (1.5 ms per century) and that deduced from tidal
friction (2.4 ms/cy).
This opens an alternative, or parallel, way (Fig. 13) of explaining
correlations between variations in Solar activity and variations in a
number of different Earth surface variables and related propositions of
solar forcingand solarterrestrial interaction(cf. Fig. 1).
9. The Future Solar Minimum
The Solar activity follows cyclic patterns. Consequently, what
happened in the past will also happen in the future. The combination of
cycles can be done in different ways. Originally, I used a combination of
the Gleissberg and De Vries cycles for the past 600 years and extended
into the Future giving a new Solar Minimum at around 20402050
(Mörner, 2005, 2006a, 2006b). In this paper, I use the Solar Irradiance
curve of Bard et al. (2000), noting that this curve, in fact, rather should
be labelled a Solar Wind Curveas it is constructed from the variations
in cosmogenic nuclides controlled by the variations in shielding
capacity of the Earth's geomagnetic eld (Fig. 13). Along this curve
(Fig. 14), I have marked the changes recorded between Gulf Stream
stage 2 (above) and 4 (below) situations. In the middle of this century
(at about 20402050), we should, by cycle extrapolation, have a st
Future Solar Minimum when the past Gulf Stream situation should
repeat; i.e. we would have a new stage 4 situation with Little Ice Age
conditions in Europe and in the Arctic.
This is in sharp contrast to the predictions by IPCC (2001) and ACID
(2004), which predict a unidirectional continued warming leading to
the opening of the Arctic basin within this century. This prediction is
based on modelling excluding the effects of the Sun, however.
Personally, I am convinced that we need to have the Sun in the
centre(Mörner, 2006a, 2006b), and having this, we are indeed facing
a new Solar Minimum in the middle of this century. Whether this
minimum will be as the past three once were (Fig. 14), or it will be
affected by anthropogenic factors, is another question.
10. Conclusions
All of three last Solar Minima (Dalton, Maunder and Spörer)
correspond to periods of signicant changes in surface heat distribu-
tion over Western Europe and the adjacent part of the North Atlantic.
At the same time, the area of Gibraltar and Northwest Africa
experienced periods of warming. The origin must predominantly be
temporal and spatial changes in SST, and the driving mechanism for
this has to be the changes in intensity and distribution of the transport
of warm, saline water along the Gulf Stream system in the North
Atlantic (Fig. 1). Any irregularity in the transport of mass (in this case
water masses) from southern to northern latitudes will inevitably
have to affect Earth's rotation (Mörner, 1984, 1988). Therefore, it
seems highly likely that the changes recorded during the Solar Minima
were all driven by the spinning-up of the Earth's rate of rotation
(Mörner, 1995b, 1996a).
The recording by Bond et al. (1997) of a strong southward
advection of drift-ice during cooling periods, including the main Little
Ice Age period (Bond et al., 2001), ts perfectly well into the present
theory of an Earth rotational acceleration during Solar Minima.
Fig. 12. The relations among Solar activity, Earth's rotation and switches between Gulf Stream 2 and 4 stages.
Fig. 13. Variations in Solar activity lead to changes in the Solar Wind and in Solar
irradiance, both of which may affect Earth's climate. The variations in irradiance are
known to be small or even minute. The variations in Solar Wind are large and strong, via
the interaction with the Earth's magnetosphere, it affects Earth's rate of rotation, by that
forcing several different terrestrial variables like the Gulf Stream beat in the North
Atlantic. Simultaneously, the shielding capacity affects the concentration of cosmogenic
nuclides (Bard et al., 2000), like the aa-index (Cliver et al. (1998). At any rate, there are
two different ways for how changes in Solar activity may affect Earth's climate. In the
present case, it is the left line that operated.
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From the cyclic repetition between Solar Maxima and Minima, one
can infer that there will be a Future Solar Minimum in the middle of
this century (Fig. 14) when it is most likely that climatic conditions
similar to those of the Little Ice Ages (Figs. 68) will re-appear.
The mechanism of how variations in the Solar Wind intensity
affect Earth's rotation is both simple (the more pressure, the slower
the rotation) and complicated (the physical transfer of impulse
moment and rotational energy). The variations in the magnetosphere
control its shielding capacity and this is easily measured by variations
in the in-fall of
Be and the production
C. Therefore, the temporal
variations of these nuclides (Bard et al. (2000) provide a measure of
the Solar activity; not irradiance (provided it is not causally linked, as
assumed by Bard et al., 2000) but Solar Wind emission.
This implies that we now have not one but two ways of how
changes in the Solar activity may affect the Earth's variables; one by
irradiance and one by rotation (Fig. 13).
The observed changes in Solar irradiance (e.g. Foukal and Lean,
1990; Willson, 1997; Pap and Fröhlich, 1999) are very small. It has
been a problem how these extremely weak perturbations in the Sun's
energy output(Bond et al., 2001) can cause the changes observed in
the decadal-to-century terrestrial climate variables. Accordingly,
Goosse and Renssen (2004) stated: unfortunately it has been difcult
to propose a convincing mechanism that would imply an oceanic
amplication of the response of climate to solar forcing.Bard et al.
(2000) used the magnetic variability of the Sun as a proxy surrogate
for irradiance uctuations. Their curve for the last 800 years is excellent
Fig. 14. The main Solar cycle in the last 800 years and its expected extension into the future. At the three past Solar minima, NW Europe, the North Atlantic and the Arctic experienced
cold phases known as Little Ice Ages. It should be noted that the seven maps of past ocean circulation changes are observationally based records. The cyclic Solar activity record can
be extended forwards into the future (dotted line) and then gives a new Solar Minimum at around 20402050. This prediction with the Sun in the centreindicating a cooling in the
near future is opposed to the unidirectional warming and opening of the Arctic predicted by the models of ACID (2004) and IPCC (2001), which do not consider Solar variability
(Mörner, 2006b).
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as a measure of the Solar Wind interaction with the magnetosphere, but it
remains a surrogateas proxy for Solar irradiance.
The geomagnetic aa-index refers to the disturbance in the Earth's
geomagnetic eld and hence provides a measure of the Solar Wind
interaction with the magnetosphere (besides a contribution, usually
subordinate, from variations in the Earth's own geomagnetic eld).
Consequently, it seems most signicant that Cliver et al. (1998) found
good correlations, for the last 120 years, among the cyclic variations in
aa-index and sunspot numbers, and between the base curve of aa
variations and the mean changes in climate. In the present analysis, it
seems obvious that it is the Solar Wind variations that affect the
Earth's rate of rotation (Fig. 13), which affects the ocean circulation by
that generation changes in climate (Fig. 12).
In the present study, I hope I have presented observational facts
indicating the effects of changes in Earth's rate of rotation driven by
variations in the Solar Wind. Whether this is the main line, or just an
additional line, in solarterrestrial interaction (Fig. 13), is for others to
nd out.
Professor Hugues Faure was an outstanding scientist. We met in the
late 60s and immediately became friends, a friendship which grew into
brotherhood within the years. Together, we draw up the lines for the
INQUA Neotectonics Commission and started the annual issuing of the
Neotectonics Bulletin (19771996). In 1979/80, we worked side by side
when I stayed at his institute in Luminy setting up a paleomagnetic
laboratory. It was a very creative and brainstorming period. Very early
did Hugues observe the differential sea level changes along the West
African coast (Faure, 1980), which meant much for me in the
formulation of the concept of geoid deformation (Mörner, 1976)and
of differential rotation with interchange of angular momentum
(Mörner, 1984, 1988). He noted the cyclic changes in African aridity
and published a very important paper challenging its future prediction
(Faure and Gac, 1981). When he started his remarkable carbon project,
he insisted that I should work with lithospheric degassing which led to
the paper by Mörner and Etiope (2002). It was a tragedy that his time
run out andthat he was not able tocontinue his carbonproject, whichhe
loved and spent so much efforts on. It was a true privilege for me to have
had the pleasure and benet to work with Hugues for more than
30 years. And I am happy to dedicate this paper to his memory and
honour; and I bow my head in respect for this great man.
I thank Professor Guiot for providing me with the St. Jérôm
database, and I acknowledge a very nice and constructive collabora-
tion within INTAS project 97.3008 on Geomagnetism and Climate
(reported at the EGSAUGEUG meeting in Nice, 2003). Finally, I want
to thank my two reviewers for excellent comments and suggestions,
which signicantly improved the paper.
Abarca del Rio, R., Gambis, D., Salstein, D., Nelson, P., Dai, A., 2003. Solar activity and
earth rotation variability. J. Geodynam. 36, 423443.
ACID, 2004. Impact of a warm arctic: arctic climate impact assessment. ACIA Overview
Report. Cambridge Univ. Press.
Bard, E., Raisbeck, G., Yiou, F., Jouzel, J., 2000. Solar irradiance during the last 1200 years
based on cosmogenic nuclides. Tellus 52B, 985992.
Barnes, R.T.H., White, A.A., Wilson, C.A., 1983. Atmospheric angular momentum
correlated with length of the day changes and polar motion. Proc. R. Soc. London, A:
387, 3173.
Bianchi, G.G., McCave, I.N., 1999. Holocene periodicity in North Atlantic climate and
deep-ocean ow south of Iceland. Nature 397, 515517.
Bjerknes, J., 1964. Atlantic airsea interaction. Advances in Geophysics. Academic Press.
Bond, G., Showers, W., Cheseby, M., Lotti, R., Almasi, P., deMenocal, P., Priore, P., Cullen,
H., Hajdas, I., Bonani, G., 1997. A pervasive millennial-scale cycle in North Atlantic
Holocene and glacial climates. Science 278, 12571266.
Bond, G., Kromer, B., Beer, J., Muscheler, R., Evans, M.N., Showers, W., Hoffmann, S.,
Lotti-Bond, R., Hajdas, I., Bonani, G., 2001. Persistent solar inuence on North
Atlantic climate during the Holocene. Science 294, 21302136.
Cliver, E.W., Boriakoff, V., Feynman, J., 1998. Solar variability and climate changes:
geomagnetic and aa index and global surface temperature. Geophys. Res. Lett. 25,
Divine, D.V., Dick, C., 2006. Historical variability of sea ice edge position in the Nordic
Seas. J. Gophys. Res. 111, 114 C01001.
Eddy, J.A., 1976. The Maunder Minimum. Science 192, 11891202.
Ezer, T., 2001. Can long-term variability in the Gulf Stream transport be inferred from
sea level? Geophys. Res. Lett. 28, 10311034.
Faure, H., 1980. Late Cenozoic vertical movements in Africa. In: Mörner, N.-A. (Ed.),
Earth Rheology, Isostasy and Eustasy. John Wiley & Sons, pp. 465469.
Faure, H., Gac, J.Y., 1981. The Sahelian draught to end in 1985? Nature 291, 475478.
Foukal, P., Lean, J., 1990. Am empiric model of total solar irradiance variations between
1874 and 1988. Science 247, 556558.
Friis-Christensen, E., Lassen, K., 1991. Length of the Solar cycle: an indication of Solar
activity closely associated with climate. Science 254, 698700.
Golovkov, V.P., 1983. Dynamics of the geomagnetic eld and the internal structure of
the Earth. In: Bucha, V. (Ed.), Magnetic Field and Processes in the Earth's Interior.
Czeck Acad. Sci., Academia, Pragúe, pp. 395501.
Goosse, H., Renssen, H., 2004. Exciting natural modes of variability by solar and volcanic
forcing: idealized and realistic experiments. Clim. Dyn. 23, 153163.
Greatbatch, R.J., Fanning, A.F., Goulding, A.D., Levitus, S., 1991. A diagnosis of interpentadal
circulation changes in the North Atlantic. J. Geophys. Res. (Oceans) 96, 22.00922.023.
Gu, Z., 1998. An interpretation of the non-tidal secular variation in the earth rotation:
the interaction between the solar wind and the earth's magnetosphere. Astrophys.
Space Sci. 259, 427432.
Guiot, J., 1990. Methodology of the last climatic cycle reconstruction from pollen data.
Palaeogeogr., Palaeoclimatol., Palaeoecology 80, 4969.
Guiot, J., 1992. The combination of historical documents and biological data in the
reconstruction of climate variations in space and time. Paläoklimatforschung//
Paleoclimatic Res. 7 (Spec. Is. 2), 93104.
Häkkinen, S., 1999. Variability of the simulated meridional heat transport in the North
Atlantic for the period 19511993. J. Geophys. Res. (Oceans) 104, 10.99111.007.
Hide, R., Dickey, J.O., 1990. Earth's variable rotation. JPL Geodecy Geophysics Prepr. 285.
Hoyt, D.V., Schatten, K.H., 1993. A discussion of plausible solar irradiance variations,
17001992. J. Geophys. Res. 98, 18,89518,906.
IPCC, 2001. Climate Change. Cambridge Univ Press.
Kalinin, Y.D., Kiselev, V.M., 1976. Solar conditionality of changes in the length of the day,
the seismicity of the Earth and the geomagnetic moment. Geomag. Aeromag. 16,
Klein Tank, A.M.G., et al., 2002. Daily dataset of 20th-century surface air temperature and
precipitation series for European Climate Assessment. Int. J. Climatol. 22, 14411453.
Kerr, R.A., 2000. A North Atlantic climate pacemaker for the centuries. Science 288,
Krymsky, P.F., 1995. Mechanism of impulse moment transfer from solar wind to the
Earth. Abstracts, 21st IUGG, Boulderm, A, p. 137.
Kushnir, Y., 1994. Interdecadal variations in North Atlantic sea surface temperature and
associated atmospheric conditions. J. Climate 7, 141157.
Lamb, H.H., 1979. Climatic variations and changes in the wind and ocean circulation:
the Little Ice Ages in the Northeast Atlantic. Quaternary Res. 11, 120.
Lamb, H.H., 1984. Some studies of Little Ice Ages of recent centuries and its great storms.
In: Mörner, N.-A., Karlén, W. (Eds.), Climatic Changes on a Yearly to Millennial
Basis. Reidel Publ. Co, Dordrecht/Boston/Lancaster, pp. 309329.
Lean, J., Beer, J., Bradley, R., 1995. Reconstruction of solar irradiance since 1610:
implications for climate change. Geophys. Res. Lett. 22, 31953198.
Lean, J., Rind, D., 1999. Evaluating sunclimate relationships since the Little Ice Age.
J. Atmosph. SolarTerrest. Physics 61, 2536.
LeMoûel, J.P., Gire, C., Jaupart, C., 1986. Sur le correlation entre la gure de la terre et les
mouvements animant les couches externs de son noyau. C.R. Acad. Sci Paris B303,
Levitus, S., 1990. Interpendental variability of steric sea level and geopotential thickness
on the North Atlantic Ocean, 19701974 versus 19551959. J. Geophys. Res
(Oceans) 95, 52335238.
Lund, D.C., Lynch-Stieglitz, J., Curry, W.B., 2006. Gulf Stream density structure and
transport during the past millennium. Nature 444, 601604.
Marsden, G.B., Cameron, A.G.A. (Eds.), 1966. The EarthMoon System. Plenum Press.
Mörner, N..A., 1973. Climatic changes during the last 35,000 years as indicated by land,
sea and air data. Boreas 2, 3353.
Mörner, N.-A., 1976. Eustasy and geoid changes. J. Geol. 84, 123151.
Mörner, N.-A., 1984 . Planetary, solar, atmospheric, hydrospheric and endogene
processes as origin of climatic changes on the Earth. In: Mörner, N.-A., Karlén, W.
(Eds.), Climatic Changes on a Yearly to Millennial Basis. Reidel Publ. Co, Dordrecht//
Boston/Lancaster, pp. 483507.
Mörner, N.-A., 1987. Short-term paleoclimatic changes. Observational data and a novel
causation model. In: Rampino, M.R., Sanders, J.E., Newman, W.S., Königsson, L.K.
(Eds.), Climate; History, Periodicity and Predictability, pp. 256269.
Mörner, N.-A., 1988. Terrestrial variations within given energy, mass and momentum
budgets; Paleoclimate, sea level, paleomagnetism, differential rotation and
geodynamics. In: Stephenson, F.R., Wolfendale, A.W. (Eds.), Secular Solar and
Geomagnetic Variations in the Last 10,000 Years. Kluwer Acad. Press, pp. 455478.
Mörner, N.-A., 1990. The Earth's differential rotation; hydrospheric changes. AGU,
Geophys. Monograph Series 59, 2732.
Mörner, N.-A., 1991. Trans-polar VGP shifts and Earth's rotation. Geophys. Astrophys.
Fluid Dynamics 60, 149155.
Mörner, N.-A., 1992. Ocean circulation, sea level changes and East African coastal
settlement. In: Sinclair, P. (Ed.), Urban Origins in East Africa. Board Antiquity,
Uppsala, pp. 258263.
292 N.-A. Mörner / Global and Planetary Change 72 (2010) 282293
Author's personal copy
Mörner, N.-A., 1993. Global Change: the last millennia. Global Planet. Change 7, 211217.
Mörner, N.-A., 1995a. Sea level and climate the decadal-to-century signals. J. Coastal
Res. 17 (Sp. I), 261268.
Mörner, N.-A., 1995b. Earth rotation, ocean circulation and paleoclimate. GeoJournal 37,
Mörner, N.-A., 1996a. Global change and interaction of Earth rotation, ocean circulation
and paleoclimate. An. Brazilian Acad. Sc. 68 (Supl. 1), 7794.
Mörner, N.-A., 1996b. Earth rotation, ocean circulation and Paleoclimate: the North
AtlanicEuropean case. In: Andrews, J.T., Austin, W.E.N., Bergsten, H., Jennings, A.E.
(Eds.), Late Quateranry Palaeoceanography of the North Atlantic Margins: Geol.
Soc. Spec. Publ., vol. 111, pp. 359370.
Mörner, N.-A., 1999. Solar Variability and Responses in the Terrestrial System: the Effects of
Solar Wind Variation on Earth's Rate of Rotation. IUGG, Birmingham. Abstracts GA 6.01.
Mörner, N.-A., 2005. Facts and ction about sea level changes. Report to the House of
Lords, Economic Affairs Committee, 6 pp. Also: Seminário, 19 Setembro 2005, Sea
level changes. Mundacas globais, variacões do nível do mar e dinamica costeira,
Univ Porto, Portugal, p. 1217.
Mörner, N.-A., 2006a. 2500 years of observations, deductions, models and geoethics.
Boll. Soc. Geol. It. 125, 259264.
Mörner, N.-A., 2006b. The danger of ruling models in a world of natural changes and
shifts. In: Burdyuzha, V. (Ed.), The Future of Life and the Future of Our Civilization.
Springer, pp. 105114.
Mörner, N.-A., Etiope, G., 2002. Carbon degassing from the lithosphere. Global Planet.
Change 33, 185203.
Pap, J.M., Fröhlich, C., 1999. Total solar irradiance variations. J. Atmosph. SolarTerrest.
Physics 61, 1524.
Pettersson, O., 1913. Klimatförändringar I historisk och förhistorisk tid. Kungl. Sv. Vet.
Akad. Handl. 51 (2), 181.
Peyron, O., Jolly, D., Braconnot, P., Bonnelle, R., Guiot, J., Wirrmann, D., Chalié, F., 2006.
Quantitative reconstructions of annual rainfall in Africa 6000 years ago: model
data comparison. J. Geophys. Res. 111, D24110. doi:10.1029/2006JD007396.
Peyron, O., Guiot, J., Cheddadi, R., Tarasov, P., Reille, M., De Beaulieu, J.L., Bottema, S.,
Andrieu, V., 1998. Climatic reconstruction in Europe for 18 000 year B.P. from
pollen data. Quatern. Res. 49, 183196.
Rind, D., 2002. The Sun's role in climate variations. Science 296, 673677.
Rochester, M.G., 1984. Causes of uctuations in the rotation of the Earth. Philos. Trans.
Roy. Soc. London A313, 95105.
Rosen, R.D., Salstein, D.A., 1983. Variations in atmospheric angular momentum on
global and regional scales and the length of the day. J. Geophys. Res. 36, 54515470.
Rosen, R.D., Salstein, D.A., 2000. Multidecadal signals in the interannual variability of
atmospheric angular momentum. Clim. Dyn. 16, 693700.
van der Schrier, G., Weber, S.L., Drijfhout, S.S., 2002. Sea level changes in the North
Atlantic by solar forcing and internal variability. Clim. Dyn. 19, 435447.
Stuiver, M., Quay, P.D., 1980. Changes in atmospheric carbon-14 attributed to a variable
Sun. Science 270, 1119.
White, W.B., Lean, J., Cayan, D.R., Dettinger, M.D., 1997. Response of global upper ocean
temperature to changing solar irradiance. J. Geophys. Res. 102, 32553266.
Willson, R.C., 1997. Total solar irradiance trend during solar cycles 21 and 22. Science
277, 19631965.
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... The cyclic planetary beat a↵ecting the Earth (Figs. 2 and 5) gives rise to a spectrum of di↵erent processes within the Earth system. This is illustrated in Fig. 6, and has been separately addressed before (Mörner, 1984a(Mörner, , 1989b(Mörner, , 2010. ...
... The fact that there is a good correlation between changes in solar activity and changes in Earth's rate of rotation (LOD -length of day) can hardly be understood in other ways than that Earth's spin rate is strongly controlled by the interaction between the solar wind and the magnetosphere (Mörner, 1996a(Mörner, , 2010. This is illustrated in Fig. 6 indicating that variations in solar wind (initiated by the planetary beat) a↵ect the shielding (in-fall of cosmic rays), the geomagnetic field strength, the pressure, the gravity and the rotation. ...
... The causation chain -solar wind variations, interaction with the magnetosphere, changes in the Earth's rate of rotation and e↵ects on the ocean circulation -plays a central role according to the present author (Mörner, 1996a(Mörner, , 2010. ...
Full-text available
The Sun’s activity constantly varies in characteristic cyclic patterns. With new material and new analyses, we reinforce the old proposal that the driv- ing forces are to be found the planetary beat on the Sun and the Sun’s mo- tions around the center of mass. This is a Special Issue published on Pattern Recognition in Physics where various aspects of the Planetary–Solar–Terrestrial interaction are highlighted in 12 independent papers. The Special Issue ends with General Conclusions co-authored by 19 prominent specialists on solar- terrestrial interaction and terrestrial climate. They conclude that the driving factor of solar variability must emerge from gravitational and inertial effects on the Sun from the planets and their satellites. By this, an old hypothesis seems elevated into a firm theory, maybe even a new paradigm.
... If temperature continues to rise, sea level is likely to rise by about 10 cm up to year 2100 in the northern hemisphere and remain more or less stable in the equatorial region. If, on the other hand, we will face a new Grand Solar Minimum by about 2030-2050 [51] [52] [54], sea is likely to fall in the north and rise in the equatorial regions ( Figure 6). ...
... [19]) documenting a high sea level during the cold period of the 17 th century, a low sea level during the warm period of the 18 th century, and a rise to a moderately high sea level in the early 19 th century of cold climate conditions can only be understood in terms of variations in Earth's rate of rotation; speeding-up during Grand Solar Minima and slowing-down during Grand Solar Maxima [50] [51] [52] [53].This implies that water masses are dislocated from the north to the equatorial bulge at the speed-ups during Grand Solar Minima. Arctic water is pulled down all the way to central Portugal initiating Little Ice Age climate conditions in Europe and the North Atlantic[51]. At the same time the equatorial bulge increases (by about 60-70 cm in the 17 th century and by about 20-30 cm in the early 19 th century as shown inFigure 6).At Grand Solar Maxima, the Gulf Stream penetrates far up into the Arctic providing warm and nice climate conditions in the whole of NW Europe[51]. ...
... Arctic water is pulled down all the way to central Portugal initiating Little Ice Age climate conditions in Europe and the North Atlantic[51]. At the same time the equatorial bulge increases (by about 60-70 cm in the 17 th century and by about 20-30 cm in the early 19 th century as shown inFigure 6).At Grand Solar Maxima, the Gulf Stream penetrates far up into the Arctic providing warm and nice climate conditions in the whole of NW Europe[51]. The equatorial bulge, however, decreased by up to 70 -100 cm in the 18th century, and by 10 -20 cm at about the climate cooling in 1960-1970. ...
... This weakens the warm AW transport to the Arctic and may result in the Gulf Stream beat (GSB) between two branches-the northern or southern branch [14] as illustrated in [1] Figure 1. ...
... The sunspot-cycle length varies between 8 and 15 years with an average of 11.06 years. The amplitude spectrum has 4 peaks at 9.97, 10.66, 11.01, and 11.83 years [14]. The strongest peak at 11.01 years is close to the Venus-Earth-Jupiter recurrent cycle of tidal torque (P VEJ ) which produce an increase in the rotation of the outer layers of the Sun for 11.07 years and a decrease in the next 11.07 years, making a full cycle of 22.14 years, which is close to the solar magnetic cycle of S H = 22 ± 1 years [108]. ...
... Nevertheless, later studies showed a stronger temporal connection between the LIA and volcanic eruptions (Brönnimann et al., 2019;Crowley et al., 2008;Hegerl et al., 2003;Owens et al., 2017). Regardless the reasons, the Atlantic circulation system was influenced by the LIA cooling such that the cooler polar glacial waters continually penetrated the more southern realms and caused ice ages particularly in NW Europe and the Balkans (González Trueba et al., 2008;Hughes, 2009;Mörner, 2010;Zasadni, 2007). ...
Despite global and local evidence of significant precipitation changes since the Little Ice Age (LIA), their impact upon lake hydrology and surrounding vegetation has yet to be investigated in NW Anatolia. Moreover, the LIA, as a trigger to the social/political recession of the Ottoman Empire in the 17th century is expected to have these impacts. To address this important gap, we studied three cores from Lake Sünnet, a landslide-dammed high altitude lake with extreme sedimentation rates, by using a wide range of proxies including lithology, stable isotopes of O and C, diatoms, pollen, and ostracods. The LIA timespan of AD 1510–1750 is represented by poorly preserved diatom flora and scarce ostracod fauna that collectively suggest very shallow aquatic conditions. The period AD 1640–1710 within the LIA is standing out with higher Abies and total herb pollen percentages that denotes considerably cooler conditions. During and soon after this cold and dry period precisely overlapping the Maunder Minimum, the currently deep Lake Sülüklü in close vicinity was a dry lowland where tall trees were growing. Progressive warming/lake level rise in Lake Sünnet after the AD 1750s is suggested based on a continuous diatom record with increasing planktonic share, increase in diverse and warm demanding arboreal cover, and a positive shift in δ ¹⁸ O of the lake muds. Following the relatively dry/cold period of AD 1800–1850 (Dalton Minimum) when the lake level was stationary and Artemisia cover became the most expanded of the whole record, a relatively warmer climate has dominated the area until the end of the 20th century.
... The climatic deterioration inferred from the Spur Bog record conforms strongly to contemporary accounts from southern England which detail cold winters, wet summers and frequent coastal storms throughout the 16th century AD [46][47][48]52,53], typically associated with the onset of the 'Little Ice Age' (LIA) cooling period experienced across Europe at 1500 AD [55,56]. Low wildfire activity at the Spur Bog and surrounding area during the late 15th and 16th centuries AD, evidenced by reduced macro-and microcharcoal fragment counts, are furthermore indicative of the climatic deterioration identified across Britain and north-western Europe during the early LIA [57][58][59]. Climatic conditions lasted at Spur Bog until~1610 cal AD as supported by continuing decreasing arboreal pollen and increasing Poaceae concentrations and stagnating values in LOI (Figures 7 and 8). The onset of peat deposition at that time indicates the establishment of a terrestrial wetland environment at Spur Bog. ...
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A multi-proxy palaeoenvironmental dataset (LOI, pollen, charcoal, grain sizes and the humification index) was extracted and radiocarbon dated from a sedimentary sequence from Spur Bog, central South Haven Peninsula (Dorset, southern England) to reconstruct ecological and environmental changes within the last ~900 years. These analyses reveal highly unstable environmental conditions at the site, evidencing the occurrence of multiple, often rapid changes during this period. The results significantly expand upon the existing palaeoenvironmental and geomorphological frameworks of the South Haven Peninsula which previously relied upon sparse, vague historical records prior to ~1750 AD. The multi-proxy dataset of Spur Bog sediments recorded a primary “development” phase (~1150–1470 AD) during which marine processes were the dominant control upon environmental conditions at the site, resulting in marked geomorphological changes that lead to the progressive eastward expansion of the South Haven Peninsula. This is followed by a secondary “maturation” phase (~1470–1880 AD) during which the Spur Bog sequence exhibits significant ecological changes in response to fluctuations in sea level, coastal erosion and human activity, demonstrating the vulnerability of the site to future climatic and anthropogenic pressures.
... Půlroční perioda naopak ukazuje, že na pohyb atmosféry, obdobně jako na pohyb oceánů, mají vliv slapové síly (zejména Měsíce a Slunce), které ovlivňují pohyb atmosférických útvarů a vznik srážek (Andrlík a Brůžek 1967, Andrlík 1994. V širším měřítku na stejný princip ukázal Mörner (2010) v případě oceánského proudění, kdy se generálně mění směry a velikost oceánských proudů nejenom s půldenními, půlročními, 18,6letými slapy v měsíční uzlové (nodální) periodě (Ladma [online]), ale také v cca 60letém a 179letém cyklu. ...
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Precipitation and flow cycles in the Czech Republic and the surrounding Central Europe after 1800 are moderated by extraterrestrial effects on the radiant power of the Sun and on the movement of the Earth's atmosphere and water. The cycles are manifested by alternating dry and water periods of different lengths.
... An example is shown in Figure 3. The link with the lack of solar activity has attracted special attention because these two indicators have been proposed to correlate (by several authors, among them Mörner (2010) or Soon (2009), Soon (2013 for example). If "collapse" of the European civilizations is not really an appropriate term, societies were considerably weakened and populations were particularly vulnerable. ...
... Similarly, the 1800's megadrought corresponds to the Dalton Minimum (1790-1830), also a period of low solar activity and several volcanic eruptions, which coincided with a period of lower-than-average global temperatures. During this period, there was a variation in temperature of about −1°C in the central part of Europe 28,30 . The 1770-1840's megadrought event is associated with one of the driest periods over the last millennium (Fig. 3). ...
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Megadroughts are notable manifestations of the American Southwest, but not so much of the European climate. By using long-term hydrological and meteorological observations, as well as paleoclimate reconstructions, here we show that central Europe has experienced much longer and severe droughts during the Spörer Minimum (~AD 1400-1480) and Dalton Minimum (~AD 1770-1840), than the ones observed during the 21st century. These two megadroughts appear to be linked with a cold state of the North Atlantic Ocean and enhanced winter atmospheric blocking activity over the British Isles and western part of Europe, concurrent with reduced solar forcing and explosive volcanism. Moreover, we show that the recent drought events (e.g., 2003, 2015, and 2018), are within the range of natural variability and they are not unprecedented over the last millennium.
... The fact is that the climatic changes during the last 600 years include cold periods around 1450, 1690 and 1815 that correlate with the Spörer, Maunder and Dalton Grand Solar Minima [74][75][76]. The driving cyclic solar forces can easily be extrapolated into the future (Fig. 4). ...
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May low-lying islands and coastal areas be freed from the condemnation to become flooded in the near-future Nils-Axel Mörner-2005 Climate is becoming increasingly warmer we hear almost every day. This is what has become known as Global Warming. The driving idea is that there is a linear relationship between CO2 increase in the atmosphere and global temperature. The fact, however, is that temperature has constantly gone up and down. From 1850 to 1970, we see an almost linear relationship with Solar variability; not CO2. For the last 30 years, our data sets are so contaminated by personal interpretations and personal choices that it is almost impossible to sort up the mess in reliable and unreliable data. Most remarkable in the record of climatic changes during the last 600 years are the cold periods around 1450, 1690 and 1815 and their correlation with periods of Solar Minima (the Spörer, Maunder and Dalton Solar Minima). The driving cyclic solar forces can easily be extrapolated into the future. This would call for a new cold period or "Little Ice Age" to occur at around 2040-50. Still, we hear nothing about this. It is as if IPCC and the Kyoto Protocol enthusiasts want to "switch off the Sun itself". Let us take this, at least, as a piece of information to rise our awareness and curiosity. In the global warming concept, it has been constantly claimed that there will be a causal rise in sea level; a rise that already is in the accelerating mode, in the near future to cause extensive and disastrous flooding of low-lying coastal areas and islands. "It will be the death of our nation", says the President of the Maldives, and the people of Tuvalu in the Pacific claim that the flooding has already commenced. Is this facts or fiction? It is true that we are flooded by this information. But what lies behind this idea? And, especially, what do the true international specialists think? The recording and understanding of past changes in sea level, and its relation to other changes (climate, glacial volume, gravity potential variations, rotational changes, ocean current variability, evaporation/precipitation changes, etc) is the key to sound estimates of future changes in sea level. The international organisations hosting the true specialists on sea level changes are to be found with the INQUA commission on sea level changes and the IGCP special projects on sea level changes. When I was president of the INQUA Commission on Sea Level Changes and
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There is a strong linkage between Earth's rate of rotation and the changes in ocean circulation. The ocean circulation changes, in their turn, are strongly linked to the paleoclimatic evolution on the bordering land masses. This is due to the high heat storing capacity of the oceans and the ocean-air-land heat flux. We propose that the paleoclimatic changes on the decadal-to-millennial time scale are primarily driven by the causal connection between Earth's rotation and ocean circulation changes in a feed-back coupling relation. This operational mechanism is recorded in the ENSO/non-ENSO alternations and in the European instrumental records of the last 300 years. It seems successfully applicable to the historical climatic records, the 1000 AD shifts, the 16 Holocene "super-ENSO" events, the high-amplitude changes at 13-10 Ka BP, and the 20 Ka oceanic circulation. This imply that the oceanic system - in this case the ocean surface circulation - has a much more important role than previously appreciated which should significantly affect our modelling of past and future climatic changes.
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It all began with observations. With Ovidius changes and metamorphoses were incorporated in the ancient «scientific» knowledge. Aristotle's was to formulate the world's first model claiming that the Earth was in the planetary centre. This model fooled the world for 1800 years. There is a danger in ruling models. The nuclear waste handling and the global warming scenario are two such modern ruling models, both of which are here challenged because of observational facts. Geoethics calls for an increased respect for observational facts. Observation-interpretation-conclusion must be the base and backbone for science today, as it has been in the past.
Based on a quantitative study of the common fluctuations of 14 Ca nd10Be production rates, we have derived a time series of the solar magnetic variability over the last 1200 years. This record is converted into irradiance variations by linear scaling based on previous studies of sun-like stars and of the sun’s behavior over the last few centuries. The new solar irradiance record exhibits low values during the well-known solar minima centered at about 1900, 1810 (Dalton) and 1690 ad (Maunder). Further back in time, a rather long period between 1450 and 1750 ad is characterized by low irradiance values. A shorter period is centered at about 1200 ad, with irradiance slightly higher or similar to present day values. It is tempting to correlate these periods with the so-called ‘‘little ice age’’ and ‘‘medieval warm period’’, respectively. An accurate quantification of the climatic impact of this new irradiance record requires the use of coupled atmosphere‐ocean general circulation models (GCMs). Nevertheless, our record is already compatible with a global cooling of about 0.5‐1°C during the ‘‘little ice age’’, and with a general cooling trend during the past millenium followed by global warming during the 20th century (Mann et al., 1999).
Holocene sea level curves seem to have a latitudinal range of variation on the West African coast. This is probably a good indication that Holocene coastal vertical movements are related to hydro-isostatic and geoidal phenomena.-from Author
The great variability of rainfall in the Sahelian areas of Africa is well documented for all time scales during the Quaternary and historical periods. Since the beginning of the twentieth century the variability can be quantified from many meteorological and hydrological surveys1-6. The River Sénégal runoff gives a simplified view of the yearly mean rainfall over an extensive Sahelian and Sudanian area. The pattern of the annual river discharge over the nineteenth century shows short periods of drastic minimum followed by a slow return to longer periods of wet conditions with a double maximum. The mean time between the last three droughts is 31.3 yr with extreme conditions every 10.3 +/- 4 yr. Extrapolating the curve of the mean annual modules suggests that the present drought should end in 1985 with full wet conditions being re-established in about 1992. If the same pattern continues, it is feared that a severe drought will occur around 2005.
During the past ∼120 years, Earth's surface temperature is correlated with both decadal averages and solar cycle minimum values of the geomagnetic aa index. The correlation with aa minimum values suggests the existence of a long-term (low-frequency) component of solar irradiance that underlies the 11-year cyclic component. Extrapolating the aa-temperature correlations to Maunder Minimum geomagnetic conditions implies that solar forcing can account for ∼50% or more of the estimated ∼0.7–1.5°C increase in global surface temperature since the second half of the 17th century. Our analysis is admittedly crude and ignores known contributors to climate change such as warming by anthropogenic greenhouse-gases or cooling by volcanic aerosols. Nevertheless, the general similarity in the time-variation of Earth's surface temperature and the low-frequency or secular component of the aa index over the last ∼120 years supports other studies that indicate a more significant role for solar variability in climate change on decadal and century time-scales than has previously been supposed. The most recent aa data for the current solar minimum suggest that the long-term component of solar forcing will level off or decline during the coming solar cycle.