The idea of lunar-driven temperature in the Barents Sea had challenged the prevailing view of the wind theory. The moon was associated with ancient superstitions. The pioneers who first studied the topic became “radioactive” and labeled as unserious.
The prevailing opinion
In the 1800s, the German mathematician Karl Zöppritz had presented calculations showing that wind can affect currents and temperature in the ocean, if the wind lasts long enough. This theory has been accepted as the main explanation for temperature changes in the ocean right up to our time.
In 1887, the German geography professor Otto Krümmel (1854–1912) published the first major handbook of modern oceanography. Krümmel made a critical comment here about the importance of the moon and long tidal waves. At a time when modern science was taking shape, the moon was not seen as a politically or scientifically correct explanation. The wind theory of Zöppritz and Krümmel’s critical commentary therefore had a great impact and remained unchallenged right up to the present day.
Pettersson’s “moon waves”
After a lecture at an international conference in Bergen, I was contacted by the Spanish marine biologist Tim Wyatt. He said that he had collaborated with R. C. Currie, who had identified the period of 18.6 years in some of the world’s longest data series. Wyatt also tipped me off about the Swedish oceanographer Otto Pettersson. At the time, he was a leading researcher, who was little known in Norway. I contacted the library, and was sent Pettersson’s work. The material consisted of large protocols, written in the early 1900s. Here was a fascinating story.
On the west coast of Sweden, they had been recording catch data for herring for over a thousand years. These data showed large fluctuations in the herring stock, which had had a decisive impact on the economy in the area. In the 1800s, researchers began to question what could be the reason for the large variations in the population.
At this time, marine research was not very specialized, and fundamental explanations for nature’s variations were sought. The Swedish oceanographer Otto Pettersson (1848–1941) tried to find the answer. In 1909 he established a station to measure temperature profiles in the Gullmarfjord outside Bohuslän. Here, Pettersson discovered a clear connection between the moon phases, the temperature profiles in the fjord and the recruitment of herring.
Pettersson had problems early on with Zöppritz’s wind theory. Instead, he claimed that gravity from the moon affects the different temperature layers in the ocean. Changes in these temperature layers affect the sea surface temperature, which in turn leads to temperature changes in the atmosphere. We experience these atmospheric changes as climate variations. Pettersson supported his theory by analyzing temperature data from the Ona lighthouse. Pettersson thus argued that it was not primarily the weather that controlled the ocean’s temperature changes, but the moon that affected the sea temperature, and thus also the weather.
He calculated that the moon’s orbit undergoes small changes with periods of 9, 18, 93, 111, 222, and all the way up to 1433 years. Pettersson believed that these periods led to long tidal waves that affected the climate. According to him, these “moon waves” could explain historical climate variations 1000 years back in time. Furthermore, he claimed that these tidal waves were also the cause of the large herring periods in Bohuslän. By comparing long tidal waves with catch data, Pettersson found that the catch data for herring showed cycles of around 18 and 111 years. He explained these periods with the moon’s Saros cycle of 18.03 years, known from solar eclipses, and the “Great Saros” cycle of 111 years.
However, the understanding of tides at the time was based on the calculations of the 1700s from Laplace. Therefore, Pettersson’s ideas were not accepted by the leading researchers of the time. The belief that the moon could have a decisive influence on the climate and the herring population was seen as pure superstition. This stamp has since characterized oceanographic and marine biological research right up to our own time. At the same time, there was a Russian group that continued this research.
Russian “Lunar wave”
At our library, we had a librarian from Ukraine who spoke Russian. Through her, I got hold of Russian publications that were little known here in the West. It turned out that Russian scientists had continued the “Lunar-wave” theory of Otto Pettersson, which in Western countries was labeled as superstition. One of these researchers was G K Izhevskii, who had developed a system model for Arctic areas. As early as the 1930s, he and several other Russian scientists investigated the idea that the tides affected the water circulation in the Atlantic Ocean.
Particularly important were the works of Maksimov and Smirnov (1964, 1965, 1967), who estimated a standing 19-year tidal wave in the Atlantic Ocean, between the pole and the equator. They found that this long tidal wave affected the speed and circulation of the water masses, as well as ocean temperature. The temperature variations were estimated at about ± 0.2 degrees Celsius in the Atlantic Ocean and at the Kola Section. A closed Russian research community had thus, already 30 years earlier, confirmed my own calculations.
Maksimov and Smirnov (1965) rejected Zöppritz’s wind theory and instead confirmed the “lunar theory”, with roots dating back to Pettersson. In the 1960s, they concluded their research with the following comment: “Krümmel once claimed that any idea that the moon influences the weather was pure superstition. In our opinion, this judgment, which has had a major impact on science, was hasty.” Here they took a showdown with Krümmel. Later I learned that they fell out of favor. Scientists who emphasized the importance of the moon became “radioactive” and got into trouble. At the same time, a new era came, which created new opportunities.
Curries lunar cycle
In the 1960s, computers made it possible to calculate periodic changes in large data series. At the time, Burg was working on the analysis of measurements from underground nuclear explosions. In this work, he developed a new method for identifying periodic patterns, based on Fourier’s spectrum transformation. After the method was released, he trained his colleague, Currie, who quickly understood the possibilities of this new analysis method.
Between the 1960s and the 1990s, Currie analyzed hundreds of climate data series from around the world. These results were published in several articles from the 1970s and throughout the 1990s. Currie’s analyses showed that a clear cycle of about 18.6 years existed in a wide range of climate data series. He found this 18-year cycle in data series for precipitation in the United States, England, and Africa. He also found the same cycle in annual growth in tree rings, historical disease prevalence, emigration to America, wine production in France and catch data for cod in Lofoten. In Egypt, the water level in the Nile had been measured for thousands of years. These measurements also showed the same 18-year cycle, confirming that rainfall in Africa was part of the same phenomenon.
Currie demonstrated that we were facing a global phenomenon here. The analyses showed that these periodic climate changes had a significant impact on fisheries, agriculture and economic development over several hundred years. He demonstrated that the cycle of 18.6 years could be traced back to variations in the moon’s orbit. Currie therefore drew the obvious conclusion that changes in the moon’s orbit affected the Earth’s climate by a period of about 18 years. The problem was that Currie couldn’t explain why this cycle existed in the data series. The results were therefore seen as a strange phenomenon, without being taken particularly seriously by contemporary researchers. Even though Currie based his research on real data, he was met with skepticism. The simple explanation is that the moon was associated with old science and that new science is looking for something new. There is also a deeper explanation that revolves around how we perceive nature’s nature.
Tne natures nature
The significance of the moon told me that this topic is really about our basic understanding of how nature works. Charles Darwin (1809–1882) launched the idea of evolution in ecosystems – a self-regulating system in which random changes adapt to the environment. This perspective has characterized the field of biology right up to the present day. The consequence has been that changes in the cod stock are typically explained by a random imbalance between predators and prey: There is too little cod because there is too little capelin, because the herring eat too many fry, because the catches are too large, or because there are too many seals.
But there is also another Darwin: George Howard Darwin (1845–1912), son of Charles, who was probably the first to understand that the earth and the moon must be considered as a unified dynamic system. He discovered the lunar node period of 18.6 years in tidal tables for the approach to London. Georg Darwin proposed that the tides led to vertical mixing in the ocean, with major consequences for the climate and ecosystems. The interesting thing is that father and son Darwin had diametrically opposed perspectives on nature’s changes.
Charles Darwin promoted a kind of “market-driven” model of random adaptations. George Darwin presented a deterministic perspective, in which the moon’s gravity was the fundamental driving force. According to this perspective, the cod population changes because the moon influences the growth of the entire ecosystem.So why did the pioneers get into trouble with the moon. The answer may be that the importance of the moon opens the notion that there is something outside of us, which affects life on our Mother Earth.