From The Niels Bohr Institute [Niels Bohr Institutet] (DK): “Danish astrophysics student discovers link between global warming and locally unstable weather”

Niels Bohr Institute bloc

From The Niels Bohr Institute [Niels Bohr Institutet] (DK)


University of Copenhagen [Københavns Universitet] [UCPH] (DK)

23 May 2022

By Peter Laursen
Cosmic Dawn Center
Phone: +45 35320519
Mobil: +45 30265969

Albert Sneppen
Phone: +45 2897 6434

Local temperature fluctuations on Earth in the 1880s (left), compared to today (right). White colors show the average temperature during the period 1951–1980, while blue and red show colder and warmer temperatures, respectively. Globally, the temperature has increased roughly 1 °C over this period, but locally the variations may be greater or smaller. Now, new research sheds light on the link between these variations and the unstable weather. Source: NASA’s Scientific Visualization Studio.

With over 99 percent agreement among climate scientists, it is now clear that Earth is warming globally and that this warming is predominantly human-made.

Temperature increases faster than ever before, and Earth is probably at its warmest for over 100000 years. Since the beginning of the Industrial Revolution about 250 years ago the world has become 1.1 °C warmer.

Global and local warming

Climate change in recent years has given us extreme heat records, such as last year, when Canadians measured their highest temperature at almost 50 °C; five degrees warmer than the previous record!

But the problem is not limited to heat records: Cold waves; droughts storms and precipitation also reaches new heights.

How global warming gives rise to local weather extremes is an active though not yet fully understood field of research. But with a new mathematical approach, master student Albert Sneppen just came one step closer to the connection between global temperature rise and the instability of local weather.

Inspiration from early Universe

Albert Sneppen spends his time studying astrophysics at the Cosmic Dawn Center, a basic research center under the Niels Bohr Institute and DTU Space in Copenhagen, and is used to pondering on black holes and exploding stars. One day he got the idea that a method normally used to analyze the distribution of light on the night sky could also be used to study the distribution of temperature fluctuations on the Earth’s surface.

The method is used in particular to interpret the so-called cosmic microwave background radiation, also known as the “Big Bang afterglow”. Suddenly Albert Sneppen saw a kind of “aesthetic coincidence” between heat distribution on the Universe’s scales and the Earth’s scales.

“For decades, the heat radiation of the early Universe has been studied in the night sky. Researchers use the so-called »angular power spectrum« which tells you how much all parts of the night sky — both locally and globally — are connected. And that is exactly what you want in climate research; a method of examining all scales of climate change at the same time,” Albert Sneppen explains.

Albert Sneppen With a new mathematical approach, Albert Sneppen has come one step closer to the connection between the global temperature rise and the instability of the local weather.

The structure of climate

The new mathematical perspective supports hitherto unknown structures in the climate.

In addition to reproducing Earth’s temperatures and confirming the observed climate trends on the largest scales, it shows how local weather fluctuations are created, i.e. on small scales. It turns out that fluctuations and differences on large scales are followed by fluctuations and differences on small scales.

”When we humans perturb Earth’s temperature on the largest scales, it causes larger temperature differences on all scales from regions of about 2,000 km, and all the way down to 50 km,” Albert Sneppen explicates.

To the left is a map of Earth’s global temperature. This “total” temperature can also be described as a sum of temperatures on coarse (large) scales, temperatures on finer scales, even finer scales, etc. On large scales we see the well-known climate changes. Albert Sneppen’s study documents that the temperature differences become stronger on small scales (Credit: Albert Sneppen).

In other words, climate change makes the differences in temperature grow locally — and with large temperature differences come even more extreme weather patterns.

“The instability and volatility of the weather has generally grown since the industrial revolution, but has especially gained momentum over the last 40 years,” says Albert Sneppen. “Together with several other theoretical and observational studies, this model indicates that the weather will become even more unstable in the coming decades.”

Albert Sneppen’s article has just been published in The European Physical Journal Plus.

See the full article here .


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Niels Bohr Institute Campus

The Niels Bohr Institutet (DK) is a research institute of the Københavns Universitet [UCPH] (DK). The research of the institute spans astronomy, geophysics, nanotechnology, particle physics, quantum mechanics and biophysics.

The Institute was founded in 1921, as the Institute for Theoretical Physics of the Københavns Universitet [UCPH] (DK), by the Danish theoretical physicist Niels Bohr, who had been on the staff of the University of Copenhagen since 1914, and who had been lobbying for its creation since his appointment as professor in 1916. On the 80th anniversary of Niels Bohr’s birth – October 7, 1965 – the Institute officially became The Niels Bohr Institutet (DK). Much of its original funding came from the charitable foundation of the Carlsberg brewery, and later from the Rockefeller Foundation.

During the 1920s, and 1930s, the Institute was the centre of the developing disciplines of atomic physics and quantum physics. Physicists from across Europe (and sometimes further abroad) often visited the Institute to confer with Bohr on new theories and discoveries. The Copenhagen interpretation of quantum mechanics is named after work done at the Institute during this time.

On January 1, 1993 the institute was fused with the Astronomic Observatory, the Ørsted Laboratory and the Geophysical Institute. The new resulting institute retained the name Niels Bohr Institutet (DK).

Københavns Universitet (UCPH) (DK) is the oldest university and research institution in Denmark. Founded in 1479 as a studium generale, it is the second oldest institution for higher education in Scandinavia after Uppsala University (1477). The university has 23,473 undergraduate students, 17,398 postgraduate students, 2,968 doctoral students and over 9,000 employees. The university has four campuses located in and around Copenhagen, with the headquarters located in central Copenhagen. Most courses are taught in Danish; however, many courses are also offered in English and a few in German. The university has several thousands of foreign students, about half of whom come from Nordic countries.

The university is a member of the International Alliance of Research Universities (IARU), along with University of Cambridge (UK), Yale University , The Australian National University (AU), and University of California-Berkeley , amongst others. The 2016 Academic Ranking of World Universities ranks the University of Copenhagen as the best university in Scandinavia and 30th in the world, the 2016-2017 Times Higher Education World University Rankings as 120th in the world, and the 2016-2017 QS World University Rankings as 68th in the world. The university has had 9 alumni become Nobel laureates and has produced one Turing Award recipient.