Opinion paper by J. van Vliet
Master in Engineering and Master in Sciences
Belgium and France were recently affected by an extreme heat wave that took place between 24 and 27 July 2019. This heat wave was in many aspects presented as unprecedented and it has therefore unlocked a large scale reaction by many media. After a few days to cool down, the time has come to express a non-emotional and non-political opinion about such a strong heat wave.
Emotional reactions were normal in such circumstances: the temperatures were extreme and even if France and Belgium were much better prepared that for the 2003 heat wave, the present heat wave has led to important suffering for many poor people or people in bad health and without access to air conditioning.
The heat wave unlocked also many political reactions: it was an opportunity to press once more the threatening mantra of United Nations and IPCC that mankind is responsible for this catastrophic warming and is destroying its own and only planet. A whole caste of politicians, countless academics and so-called « experts », lobbyists, bureaucrats and NGOs claim that it is urgent to take « strong » measures going up to the replacement of democracy by climatist despotism: even children are enlisted in the political arena. These people number in hundreds of thousands and probably more and they communicate loudly and repeatedly at the UN, through IPCC reports and COP events, in the media and in the streets. Does this imply they are right ? Has mankind something to do with these high temperatures ?
Let us look coolly at some facts.
The July 2019 western European heat wave
Heat waves are periods where temperatures largely in excess of the average values are sustained for more than a few days, over a relatively large zone.
The heat wave of late July 2019 did not start in Belgium or in France: a first observation was made on July 14 to 16 with a maximum temperature of 21 °C at the Canadian Forces Station of Alert, the world northwest permanent station (82° latitude) located on the island of Ellesmere, barely 800 km from the geographic North Pole. Starting from Alert, relevant temperature observations of July 2019 are collected in the following Table 1.
Table 1 provides for each measurement station the latitude, the first and last day of the heat wave, the observed peak temperature, the July average maximum temperature and the temperature anomaly, i.e. peak minus average maximum. The measurements stations were selected along a line joining Alert, Svalbard and major cities of Western Europe in the hope to observe a trend.
The table shows that Longyearbyen and Copenhagen were apparently spared by the heat wave: the latter is indeed observed too early at Longyearbyen, and there is no significant temperature anomaly observed in Copenhagen. The other stations show temperature anomalies ranging between 11 and 17 °C, the largest deviations being observed in Brussels and Paris. A striking result is that the heat wave did not last for more than a few days, starting a little bit earlier in the far North, and that it stopped in the south of France (Avignon) and did not reach Lisbon. The zone affected by the heat wave is at least 3.000 km long in the North-South direction: this is a truly global heat wave.
|Table 1: Observations of the July 2019 western European heat wave|
|Dates July heatwave||Peak T °C||July average Tmax °C||
|Longyearbyen, Svalbard, Norway||78,2||6||20||7,0||13,0|
|Nord Kapp, Norway||71,2||19-22||25||12,6||12,4|
|London, United Kingdom||51,5||23-25||34||23,6||10,4|
With such evidence, it is very difficult to imagine an atmospheric circulation pattern that could bring almost simultaneously hot air along a 3.000 km zone.
The July 2018 European heat wave
Very similar to the 2019 heat wave and almost at the same date, the European heat wave of July/August 2018 was marked by extreme temperatures in the Arctic, with a temperature of 32,7 °C measured on July 30, 2018 on the Banak peninsula, 400 km North of the polar circle, corresponding to an anomaly of 19 °C. Other observations are reported hereunder in Table 2. The heat wave is observed over whole Norway, down to Brussels: the latitudinal extent is a little bit smaller than for the 2019 heat wave, but reaches nevertheless 2.300 km.
|Table 2: Observations of the July 2018 European heat wave|
|Station||Latitude||Dates heatwave||Peak T °C||July average Tmax °C||
|Longyearbyen, Svalbard, Norway||78,2||1/8-2/8||15||7,0||8,0|
|Nord Kapp, Norway||71,2||29/7-1/8||29||12,6||17,4|
Where the hot air comes from?
The latitudinal extent of both 2018 and 2019 heat waves is very large at 2.000 or 3.000 km and they extend both in the Arctic regions. How could hot air be transported at about the same time over such a large distance ? And if such transport is not possible,
Figure 1. Temperatures anomalies above Europe on July 26, 2019.
- The arrival of hot air from the south like North Africa is the official meteorological explanation for the 2019 heat wave in France: for France, North Africa is the next door and this is thus an easy and good story; but even if it cannot be excluded, it is lacking credibility as the South of France was practically less affected by temperature anomalies than the North of France or Belgium. Moreover, such African air is simply unable to reach quickly enough Northern Europe or a fortiori the Arctic, as this should require a sustained southern wind of 30 to 40 km/h over a period of 48 to 72 hours.
- A strong jet stream can transfer quickly air masses over long distances; when the jet undulates, it can transfer air masses in the meridional direction (towards north or south); but the jet stream during both 2018 and 2019 heat waves was weak, and it did not flow above Norway during the periods of interest.
- The heat waves of 2018 and 2019 coincided with a very stable weather pattern, with no winds, reduced night cooling and practically no clouds. Such very stable weather was confirmed by the absence of windpower generation over France reported in 2019 by the media during the period of interest.
Following the principle of Conan Doyle’s most famous detective Sherlock Holmes, « when you have excluded the impossible, whatever remains, however improbable, must be the truth »: if long range transport of hot air is not feasible, the only possibility to get heat waves is that hot air be produced « in situ » or locally, by a combination of factors enhancing the heating of the whole troposphere, without the mixing of air masses, the solar heat input and the albedo being seasonal factors.
To fix the ideas for the solar heat input, a vertical dry air column of 1 m² cross section going up to the top of the atmosphere contains approximately a mass of 10.000 kg of air with a specific heat of 1000 J/kg.K. The heat expressed in kilowatthours necessary to achieve a heating of 10 K over the whole column is thus given by:
Taking into account the total solar irradiance of 1.365 W/m² at equinox (March 20), the solar energy delivered daily to a 1 m² horizontal ground parcel at the equator is 10 kWh, over a period of 12 hrs. At the northern hemisphere summer solstice (June 21), the total solar irradiance is a little bit smaller (the Earth is farther from the Sun) and the energy delivered daily to a 1 m² horizontal ground parcel at the polar circle is 12 kWh over a period of 24 hrs. The latter figure depends on the angle of inclination of 23,5° of the Earth rotation axis with respect to the normal to the ecliptic plane where the Earth orbits.
In the above estimates, no albedo has been taken into account, assuming a clear sky and the complete melting of the snow cover, the latter condition being met only in July for the highest Arctic latitudes.
This comparison provides evidently a possible explanation for Arctic heat waves, as far as there is no mixing of air masses: the solar heating at summer solstice in Arctic regions is indeed sufficient to build up anomalies of 10 K in two to three days. This heating appears however not sufficient to explain the anomalies ranging between 15 and 19K that were actually observed in the Arctic both in 2018 and 2019.
If the solar heating is not sufficient to reach the observed high temperatures anomalies, one should not exclude an additional heating acting on the top of the troposphere.
The Earth is indeed continuously bombarded by extraterrestrial charged particles, like the solar wind and the cosmic rays. These charged particles interact with the Earth planetary magnetic field. There are strong indications that these charged particles play a much more important role than considered up to now:
- In our solar system, there are 7 planets with an atmosphere, and 5 planets with a significant magnetic field: the two planets with atmosphere but without magnetic field, namely Venus and Mars, have both an atmosphere containing more than 96% of CO2 ; all magnetic planets have an atmosphere containing more than 95% hydrogen + helium, very similar to the solar wind composition. One shall argue that this is not true for the Earth: but if we neutralize the oxygen produced by photosynthesis, the 1400 billions of km3 of water of the biosphere correspond to an atmosphere containing 98% of hydrogen: the atmosphere of Jupiter contains 99% hydrogen + helium [Note 1].
- If charged particles penetrate the terrestrial atmosphere, they do so following the magnetic field lines; most particles enter therefore the atmosphere in the vicinity of the magnetic poles, where the density of field lines is highest. If these charged particles contribute to heating, this heating should be mainly visible in the polar regions. This could explain the relatively « accelerated » warming of the Arctic with respect to the rest of the Northern Hemisphere.
- When the energetic charged particles penetrate the upper layers of the atmosphere, they are slowed down at very high altitude by interaction with the increasingly dense plasma; according to the laws of electromagnetism, this slowing down generates emission of electromagnetic radiation (one speaks of « Bremstrahlung »), and a part of this radiation is absorbed in the top layers of the troposphere as a downward heat flux. This can explain the correlations found by Ole Humlum between solar activity and temperature for the Svalbard region.
Of course, the hypothetical downward heat flux at the top of the troposphere has nothing to do with the total solar irradiance: the latter heats the ground and this generates the bottom heat flux (also called « outgoing long wave radiation ») driving atmospheric convection. The top downward heat flux is necessarily extraterrestrial, and there is only one serious candidate: the solar wind.
Introduction to the solar wind, the hidden side of solar activity
The Sun is emitting electromagnetic radiation at a nearly constant rate of 1.365 W/m² at the distance of the Earth, this radiation being called total solar irradiance (TSI). But it is also emitting, at a highly variable rate, energetic charged particles constituting the solar wind.
One visible manifestation of the solar wind is the comma-shaped tail the comets get when they orbit near enough to the Sun. The most spectacular manifestation are auroras, boreal or austral that are observed in the arctic or antarctic regions and sometimes at lower latitudes. When the solar wind is extremely sudden, intense and energetic like during solar coronal mass ejections, dangerous manifestations are the magnetic storms and their destruction potential for electrical networks and the risk of radio-communication or GPS blackout.
Sunspots have been observed and reported since many centuries, and they form since the work of Edward Maunder the basis for the Sun historical record as a sequence of solar cycles: we are since the end of 2008 in the solar cycle 24 and precursor sunspots of the next cycle 25 have already been observed. Contrary to the sunspots, one had to wait for the space age to perform meaningful measurement of the solar wind. This is probably the reason why sunspots are still considered by some astronomers as the sole manifestation of solar activity. It is the view of the author that by far the largest impact of solar activity occurs through the solar wind.
Since the late sixties, satellites measure the speed and the density of the solar wind at the first Lagrangian point of the Sun-Earth system, i.e. at the point located at approximately 1,5 million km from the Earth where the Earth and the Sun have the same gravitational pull. The main components of the solar wind are electrons, protons and alpha particles, under the form of an interplanetary plasma with a high electrical conductivity. The speed of the protons varies between 350 and 700 km/s, their density varies between 1 and 15 proton/cm3, all these variations being sometimes very rapid. While the interplanetary flow of solar wind is well understood since the work of Eugen Parker (1958), there is still no satisfactory explanation for the process generating the solar wind itself, i.e. the enigmatic heating of the solar corona up to 1 million K, compared to the photospheric minimum of 4.000 K just above Sun surface.
Magnetosphere and solar wind
The solar wind interacts strongly with the Earth magnetic field, and two extreme cases can be considered.
When the solar wind changes very quickly, it leads to significant changes of the Earth magnetic field, resulting in magnetic storms, the prototype of such storms being the Carrington event of 1859. In their pioneering work of 1931 about the magnetic storms, Chapman and Ferraro came to the conclusion that in response to a very fast increase of solar wind, a cavity centered on Earth should form by magnetic induction, around which the solar wind should be deflected. This theory was verified with success and refined into modern MHD models. The radius of the Chapman-Ferraro cavity represents classically the radius of the « magnetosphere » estimated in the literature to 10 times the Earth radius. And classically, it is a widespread view that this magnetosphere cannot be penetrated by the solar wind.
But the situation is completely different when the solar wind changes very slowly. In this case, the magnetic induction can be neglected and the Earth magnetic field remains unchanged. The charged particles of the solar wind are captured at some distance of the Earth by the magnetic field lines and follow them downwards until they reach the atmosphere. This happens along an oval zone centered on the geomagnetic pole as shown in the Figure 2 for the Northern Hemisphere: this zone is called the Auroral Oval because it is the place where most boreal auroras are actually observed.
Figure 2.Northern hemisphere Auroral Oval. Source here.
Another phenomenon connected to the entry of solar wind in the atmosphere is the formation of noctilucent clouds in the mesosphere, at an altitude of 85 km: these clouds are so high they are visible late at night or very early in the morning. An excess of such clouds has been observed in August of this year, and correlated to an abnormally high humidity level in the mesosphere: the latter is best explained by extraterrestrial processes (like the oxidation of solar wind protons).
The conclusion appears clear: the magnetosphere does not prevent the very slowly changing component of the solar wind to reach the Earth atmosphere. It is an easy task to determine this component by simply filtering the measurements in order to keep the lowest frequencies. We obtain then the quasi static solar wind.
Variation of the solar wind proton flux over the period 2001-2019
If one wishes to estimate the impact of solar wind on the terrestrial temperatures, one has to estimate the number of protons reaching the atmosphere, this number being proportional to the flux of protons multiplied by the planetary cross-section. In order to fix the ideas, we shall apply the proposed filtering process to the proton flux, i.e. the product of the proton density (expressed in proton per cm3) by the proton speed (expressed in km/s or in cm/s): the flux is expressed in proton/cm2.s. The starting data are the daily solar wind measurements over the period January 1st, 2001 up to August 15, 2019. In order to filter the high frequencies, we replace the value for each day by the average over one year centered on the same day. The result obtained is the red curve in Figure 3. The blue curve gives in arbitrary units the number of sunspots starting from January 1st, 1999, with identical the same filtering.
The period 2001-2019 covers 2 solar cycles: during the cycle 23, the maximum sunspot number and the maximum proton flux are reached almost simultaneous at the beginning of 2002; in the cycle 24, the maximum sunspot number is reached in 2014, and the maximum proton flux is only reached 3 years later. Visual inspection of cycle 23 shows sunspot number and proton flux decreasing similarly with a delay of about 1.5 to 2.5 years for the proton flux. But for the cycle 24, there is a complete opposition between sunspot number and proton flux evolutions: the first decreases continuously to zero after 2014, while the second is multiplied by a factor 3.
Another way to express the difference between the two cycles is the following:
- For the maximum sunspot number, the ratio cycle 24/cycle 23 equals 64%;
- But for the maximum proton flux, the same ratio equals 145%.
One should stress that the apparently « weaker » cycle 24 is actually 45% stronger than cycle 23 for the solar wind. This is qualitatively confirmed by the intense auroral activity of the last few years.
Solar cycle 24 is definitely a game changer with respect to cycle 23.
Proton flux and temperatures
As already mentioned, the largest impact of solar activity on our planet takes place through the solar wind: the exceptional character of the solar cycle 24 should have an exceptional impact on the Earth temperatures.
In the Figure 3, the red triangles indicate the years where global heat waves have been observed in the Northern Hemisphere. The European heat waves of 2003, 2018 and 2019 are easily recognized. The period 2015-2019 corresponds very precisely to the period where, by an unknown mechanism, the average proton flux has largely exceeded the value of 1.5 108 p/cm².s to reach a maximum value of 3.4 108 p/cm².s. This period can be rightly pointed out as exceptional for the proton flux as well as for Earth temperatures.
The blue triangles in the same Figure 2 indicate the coldest winters registered in Belgium since the year 2000. For instance, on January 10, 2009, the Maritime Canal Brussels-Willebroek was frozen close to the power station of Verbrande Brug, something the author has never seen since 1968. During the years 2009 to 2012, the average proton flux remained close to 108 p/cm².s.
In his 1976 analysis of the Maunder Minimum, Jack Eddy noted that the very cold period between 1645 and 1715 was poor in sunspots – this is well known – but that it was also poor in auroral activity. This is an indication that the Little Ice Age was characterized by a low proton flux and this appears completely in line with the evidence presented in this paper.
One should note that neither the solar wind nor the proton flux do get any mention in the IPCC report WG1AR5.
Some words of conclusion
To summarize, observations show that the European heat waves of 2018 and 2019 are global in the sense they have a latitudinal extent of the order of 2.000 to 3.000 km. They can be explained by in situ heating of air by the seasonal solar energy input. Most probably however an additional extraterrestrial heat input appears necessary in the Arctic regions to reach the very high observed temperature anomalies. Solar wind can provide such a heat input, as far as it varies slowly enough so that its charged particles can come close enough to the Earth atmosphere.
The latter condition suggests to filter off the fast changing component of the solar wind to keep the slow varying proton flux. When this filtering is performed for the period 2001-2019, one comes to the conclusion that the solar cycles 23 and 24 are fundamentally different: during cycle 24, the proton flux reaches exceptionally high values between 2015 and 2019: these values are 45% higher than the observations of cycle 23. The high proton flux correlates very well with the global heat waves and forest fires observed during this period. Oppositely, the low proton flux correlates very well with the cold Belgian winters observed between 2001 and 2019.
The conclusion of this analysis is simple: the heat waves and the cold winters observed since the year 2000 can be explained by natural processes related to the solar activity, without any influence of mankind. If one extrapolates the proton flux curve of Figure 3 to the coming years, the heat waves are probably over by the end of 2020 and the Earth is going to face some harsh winters. This is probably not the « Grand Cooling » announced by some, but we are going to feel it.
It is quite normal that meteorologists and climatologists focus on the biosphere and the troposphere but focus does not mean exclusivity. As new data about solar wind will soon become available through space missions like the Parker Solar Probe and the Solar Orbiter, it is hoped that the international organizations that did not hesitate to bluntly present in 2014 the weather in 2050 will soon accept the inevitable evidence: solar activity has an impact that may not be further ignored.
In the present opinion paper, the author gives freely his own views, in a fully independent way and without any conflict of interests, on questions of universal interest, with the advancement of mankind and science as sole purposes. The author waives any responsibility regarding the present paper. He thanks the Editorial Board of Science, Climate & Energy for useful advice and comments. To contact the author, please send your message to firstname.lastname@example.org
 see UN General Assembly Resolution 43/53 of 6 December 1988 and many others
 « climatist » means related to the activism of climatology, just like ecologist or veganist are related to
other types of activism
 1 kilowatt.hour is equal to 3.600.000 Joule or 3,6 Megajoule.
 N. Meyer-Vernet, Basics of Solar Wind, Cambridge University Press 2007
 W.W. Soon, S.H. Yaskell, The Maunder Minimum and the variable Sun-Earth Connection, World Scientific Publishing, 2003-2007
 the International Astronomic Union supports such view, see press release IAU 1508 of 2015
 speeds in excess of 2.000 km/s can be observed during coronal mass ejections
 the Russian heat wave of 2010 is not in our list, as it was meteorologically connected to the Pakistani floods, see https://journals.ametsoc.org/doi/full/10.1175/JHM-D-11-016.1
 J. Eddy, The Maunder Minimum, Science, 18 June 1976, Volume 192, Number 424
[Note 1]. In other words, the hydrogen present in the water of the atmosphere and the terrestrial biosphere is the footprint of the solar wind, which is composed of 80% by weight of hydrogen (protons) and 20% of helium (alpha particles). Helium escapes from the Earth’s atmosphere while it remains in the atmosphere of Jupiter: this footprint found in the 5 magnetic planets (Earth, Jupiter, Saturn, Uranus, Neptune) shows that the solar wind penetrates significantly into the atmosphere.