Why climate models fail.
Instead of El Niño, La Niña 2020/21 came.
Post Februray 26, 2021, last update March 14; see: box at the end (“La Niña 2020/21 weakens”)
For many decades El Niño has been a scientifically known and much studied climate event in the Equatorial Eastern Pacific (EEP). If climate models had even the slightest hint of reliability, there would have to be at least something in the forecast that an El Niño will have had a large impact on the weather since autumn 2020. That turned out to be completely wrong. A La Niña has dominated the scene for more than a year and continues to do so. Such failures raise the question of whether science even understands what it is trying to talk about.
What matters most is the dimension and the conditions of the ocean. In the current case a paper from the Germany’s Potsdam Institute (PIK), which did the El Niño prognosis in February 2020 (1) assumed a “Very early warning signal for El Niño in 2020 with a 4 in 5 likelihood”. At that time and many months before the conditions indicated lower than average sea surface temperature (SST) , the opposite to warmer SST, representing El Niño, while La Niña is still in place now and for some more time (see: ‘climatereanalyser.org’ maps). They are the warm and cool phases of a recurring climate pattern across the tropical Pacific—the El Niño-Southern Oscillation, or “ENSO” for short.
The weaknesses of the scientific approach of the authors, Josef Ludescher et al., Can be easily identified. According to their understanding, analyzes are possible if:
Sophisticated global climate models taking into account the atmosphere-ocean coupling as well as statistical approaches like the dynamical systems schemes approach, autoregressive models and pattern-recognition techniques have been proposed to forecast the pertinent index with lead times between 1 and 24 months….
For the sake of concrete forecasting, we employed in  high-quality atmospheric temperature data for the 1950-2011 period. An average El Niño event typically increases the climate anomaly (deviation of global mean surface temperature from pre-industrial level) by about 0.1C. This suggests that a strong El Niño event in late 2020 can make 2021 a new record year, since air temperature rise lags Pacific warming by about 3 months
How can it be that one of the world’s most important climate research institutes pays so little attention to the influence of the Pacific on the ENSO interplay. All considerations must be based on the knowledge that this climate phenomenon is largely, if not exclusively, dependent on processes in the sea. Who instead, for example, “account the atmosphere-ocean coupling”, or ”employed in high-quality atmospheric temperature data” may fail. On one hand climatology regards ENSO is one of the most important climate phenomena on Earth due to its ability to change the global atmospheric circulation, which in turn, influences temperature and precipitation across the globe. On the other hand, climatology seems unable to acknowledge that the oceans govern the climate. ENSO is the ideal model case to understand this.
To understand ENSO and its influence on the atmosphere, one has to look at the dimensions that underlie this phenomenon. If one is aware of the volume of water in the Pacific and of the amount of warm or cold water that caused the ENSO, the latter is just a “drop in the Pacific”, as can be seen from the attached figures (next). The volume of warm or cold water masses in the ENSO event can hardly be expressed in a single-digit percentage in relation to the Pacific. The north-south extension is limited to a some hundred miles, the depths under the sea surface rarely more than 200 meters. In contrast, the Pacific has an average water depth of around 4000 meters and an average temperature of + 4 ° C.
La Niña 2020/21 status February 2021
Although ENSO is a long-known climate phenomenon, climatologists still follow the view of the meteorologists 100 years ago, according to which the atmosphere is at the center of all-weather events. They are generously willing to acknowledge that the oceans play an important role, but not that ocean temperatures and their contribution to atmospheric humidity are the most crucial factors. This can be seen in the example of ENSO. Although small in oceanic proportions, the weather above can have long distance effects. Once it happen, e.g. due to a lack of trade winds, the triggering cause remains the changes in equatorial water temperatures. The attempt to use computer models and weather observation data, by atmosphere-ocean coupling, ENSO forecasts failed with the 2020/2021 forecast and will not achieve what would be necessary in the future either.
What is needed is twofold: much more ocean dada (a), and acknowledging the supremacy of the oceans in climatic change matters (b).
No ocean area is as intensive observed as the Equatorial Eastern Pacific (EEP), well over 40 years. Since recently the Tropical Pacific Observing System, TPOS 2020, sustained sampling network is the “backbone” of the system, (Details: WMO). Whether this system can even provide nearly enough oceanic data to make predictions about what is going on under the sea surface cannot be judged here, but it is unlikely and for a long time.
So the other problem remains, the climatologists’ narrow view on the atmosphere. The authors of the El Nino forecast for 2020/21 failed because they lacked the insight that without comprehensive marine data, their model calculations are at best speculations. At least this conclusion should be drawn from their dramatic false prognosis.
In conclusion climatology should realize, that any ocean space, whether in size of a few hundred square miles or as covered by ENSO, plays an important role in climate matters, and that the latter should be regarded as a gift, to understand the mechanism quicker, on who is driving the climate.
Author: Dr. Arnd Bernaerts
- (1) arXiv:1910.14642v2
- (2) Josef Ludescher, Armin Bunde, Shlomo Havlin, Hans Joachim Schellnhuber(1)
La Niña 2020/21 weakens. ENSO neutral in April / May.