Credit to Dr. Bernaerts for his writings on this subject, excerpts of which appear below.
The Island Nexus for Ocean Currents
From the Dutch: spits – pointed, bergen – mountains
The largest and only permanently populated island of the Svalbard archipelago in northern Norway. Constituting the westernmost bulk of the archipelago, it borders the Arctic Ocean, the Norwegian Sea, and the Greenland Sea. Spitsbergen covers an area of 39,044 km2 (15,075 sq mi), making it the largest island in Norway and the 36th-largest in the world.
The fact is that the winter temperatures made a jump of more than eight degrees Celsius at the gate of the Arctic Basin, after 1918. Nowadays, one century later, the event is still regarded as “one of the most puzzling climate anomalies of the 20th century”.
The overriding aspect of the location is the sea; the sea around Spitsbergen, the sea between particularly the Norwegian, the Greenland, and the Barents Seas (Nordic Sea). The Norwegian Sea is a huge, 3000 metres deep basin. This huge water mass stores a great amount of energy, which can transfer warmth into the atmosphere for a long time. In contrast the Barents Sea, in the southeast of Spitsbergen has an average depth of just around 230 metres. In- and outflow are so high that the whole water body is completely renewed in less than 5 years. However, both sea areas are strongly influenced by the water masses coming from the South. The most important element is a separate branch of the North Atlantic Gulf Current, which brings very warm and very salty water into the Norwegian Sea and into the Spitsbergen region. Water temperature and degree of saltiness play a decisive role in the internal dynamics of the sea body. And what might be the role of the huge basin of the Arctic Ocean, 3000 meters depth and a size of about 15 million square kilometers?
The difference towards the other seas mentioned is tremendous. The Arctic Ocean used to be widely ice covered in the first half of the 20th Century, the other seas only partly on a seasonal basis. Only between the open sea and the atmosphere an intensive heat transfer is permanently taking place. Compact sea ice reduces this transfer about 90% and more, broken or floating ice may change the proportion marginally. In this respect an ice covered Arctic Ocean has not an oceanic but ‘continental’ impact on the climate.
The Arctic Ocean is permanently supplied with new water from the Gulf Current, which enters the sea close at the surface near Spitsbergen. This current is called the West Spitsbergen current. The arriving water is relatively warm (6 to 8°C) and salty (35.1 to 35.3%) and has a mean speed of ca. 30 cm/sec-1. The warm Atlantic water represents almost 90% of all water masses the Arctic receives. The other ~10% comes via the Bering Strait or rivers. Due to the fact that the warm Atlantic water reaches usually the edge of the Arctic Ocean at Spitsbergen in open water, the cooling process starts well before entering the Polar Sea.
A further highly significant climate aspect of global dimension is the water masses the Arctic releases back to oceans. Actually, the outflow occurs mainly via the Fram Strait between Northeast Greenland and Spitsbergen, and together with very cold water from the Norwegian Sea basin the deep water spreads below the permanent thermocline into the three oceans.
The Spitsbergen Event 1918-1919
Beginning around 1850 the Little Ice Age ended and the climate began warming. Before that, at least since 1650 marked the first climatic minimum after a Medieval warm period, the Little Ice Age brought bitterly cold winters to many parts of the world, most thoroughly documented in the Northern Hemisphere in Europe and North America. The decreased solar activity and the increased volcanic activity are considered as causes. However, the temperature increase was remote and once again effected by the last major volcanic eruption of the Krakatoa in 1883. Up to the 1910s the warming of the world was modest.
Suddenly that changed. In the Arctic the temperatures literally exploded in winter 1918/19. The extraordinary event lasted from 1918 to 1939 is clearly demonstrated in the graph showing the ‘Arctic Annual Mean Temperature Anomalies 1880 – 2004’. But this extraordinary event has a number of facets, which could have been researched and explained. Meanwhile almost a full century has passed, and what do we know about this event today? Very little!
Studies considering the causation of the warming offer sketchy rather than well founded ideas. Here are a few examples:
• Natural variability is the most likely cause (Bengtsson, 2004);
• We theorize that the Arctic warming in the 1920s/1930s was due to natural fluctuations internal to the climate system (Johannessen, 2004).
• The low Arctic temperatures before 1920 had been caused by volcanic aerosol loading and solar radiation, but since 1920 increasing greenhouse gas concentration dominated the temperatures (Overpeck, 1997).
• The earlier warming shows large region-to-region, month-to-month, and year-to-year variability, which suggests that these composite temperature anomalies are due primarily to natural variability in weather systems (Overland, 2004).
• A combination of a global warming signal and fortuitous phasing of intrinsic climate patterns (Overland, 2008).
Arctic Regime Change
These explanations (and others such as CO2 or the AMOC) do not come to grips with how extreme and abrupt was this event. In the Spring of 1917, sea ice reached all the way to Spitsbergen, the only time in a century.
And the next year, temperatures rocketed upward, as shown by the weather station there:
A look at the SST history shows clearly an event as dramatic as a super El Nino causing a regime change. But this is the Atlantic, not the Pacific. Cooling followed, but temperatures stayed at a higher level than before.
The warming at Spitsbergen is one of the most outstanding climatic events since the volcanic eruption of Krakatoa, in 1883. The dramatic warming at Spitsbergen may hold key aspects for understanding how climate ticks. The following elaboration intends to approach the matter from different angles, but on a straight line of thoughts, namely:
- WHERE: the warming was caused and sustained by the northern part of the Nordic Sea in the sea area of West Spitsbergen the pass way of the Spitsbergen Current.
- WHEN: The date of the commencement of warming can be established with high precision of few months, and which was definitely in place by January 1919.
- WHY: the sudden and significant temperature deviation around the winter of 1918/19 was with considerable probability caused, at least partly, by a devastating naval war which took place around the British Isles, between 1914 and 1918.
There is much more evidence and analysis supporting Dr. Bernaerts’ conclusions here:
Conclusion: Unless your theory of climate change can make sense of the Spitsbergen Event, then it cannot inspire confidence. You may not be entirely convinced by Dr. Bernaerts’ explanation, but he at least has one–nobody else has even tried.