Many will be familiar with El Niño – the ocean-warming phenomenon that affects global weather patterns – but how about La Niña, which is linked to cooler sea temperatures?
According to the World Meteorological Organization (WMO), La Niña is back in the central and eastern equatorial Pacific Ocean, after nearly a decade’s absence.
This is expected to result in sea surface temperatures between two and three degrees Celsius cooler than average, said Dr. Maxx Dilley, Deputy Director in charge of Climate Services Department at WMO.
“These coolings of these large ocean areas have a significant effect on the circulation of the atmosphere that’s flowing over them. And the changes in the atmosphere in turn affect precipitation patterns around the world.”
SnowFan here reports on the latest winter forecasts for the 2020/21 Europe winter. History and statistics show Europe could be in for a frosty winter.
Currently a significant La Nina is shaping up, and history shows that these events in the Pacific have an impact on Europe’s winters:
The NOAA reanalysis above shows the temperature deviations (left) and for precipitation (right) from the WMO average 1981-2010 during the six La Niña years of winter in Europe. Large parts of Europe have average temperatures and precipitation is distributed differently, with Germany being slightly drier overall than the WMO average. Is a 2020/21 winter in Germany under La Niña conditions shaping up to have average temperatures and slightly less humidity?
Strong winter-solar correlation
A more important factor determining winter in Europe may be solar activity. Data from the German DWD national weather service since 1954 show a remarkable higher frequency of cold winters in times of low solar activity, such as we are now in the midst of.
Our friend “SnowFan” here looks at the claims that September 2020 was the warmest ever recorded. It turns out that other measurement advanced satellites don’t agree.
According to the much ballyhooed data, temperatures in Europe in September this year were on average 0.2 degrees Celsius higher than in the previous record September 2018. The service providing the data is part of the European earth observation program Copernicus.
But the satellite data from the UAH and RSS both agree that this is not really the case!
Above the global satellite data from UAH (left) and from RSS (right) in the tables clearly clearly show the monthly deviations from the WMO mean 1981-2010 (UAH) and from the climate mean 1979-1998 (RSS): September 2020 was not the warmest since satellite measurements began in 1979. At UAH, September 2019 was slightly warmer while at RSS even September 2017 was warmer.
Last week, the Global Warming policy Forum headlined “La Nina Is Here”. Why the headline? Because the warming El Nino is over and the change to the La Nina represents cooling. Like seasonal and actual climate change, it is a regular event. Which in physics means logical and predictable. And some cooling is showing up in various charts. Well, in those not altered by promoters of AGW.
As we can see, the period 1925 to 1945 was dominated by powerful El Ninos. This of course was also the time of great warming in the Arctic, known as “The Warming in The North”, when temperatures across much of the Arctic were as high as they are now.
During the 1950s, a much colder climate took over in the Arctic, until it became warmer again in the 90s. This was also a period when La Ninas dominated.
The climate in the Arctic is also very well correlated with the Atlantic Multidecadal Oscillation (AMO):
Sometimes a chance comment sets off a whole chain of investigation. Somewhere recently, in passing I noted the idea of the slope of the temperature gradient across the Pacific along the Equator. So I decided to take a look at it. Here is the area that I examined.
I’ve written about this temperature gradient before, in a post called The Tao of El Nino. If you take time to read that post, this one will make more sense. …
As far as global temperature goes it’s been a warmish start to the year, though not exceptional. This has led Carbon Brief in its three-monthly “state of the climate” report to predict that this year “is likely” to be as warm as the fourth warmest year since records began about 150 years ago. They say it could be as high as the second or as low as the 12th warmest.
Carbon Brief says, “The first three months of 2018 can give some sense of what to expect for the entire year.” But being based on a quarter of this year’s monthly measurements it could be described as either bold or foolish. Because the prediction is made without a good understanding of what has been happening to the global temperature in the past months it is probably more of the latter.
Nowhere is the Carbon Brief prediction is there any analysis of why 2018 got off to a warm start. Look towards the Tasman Sea that has been adding to global temperatures since late 2017.
The water temperature in the Tasman Sea is well above normal – 6° C more than average for the start of December. New Zealand’s summer was the hottest on record, Tasmania had its hottest November-January on record. It was exceptionally warm on both sides of the Tasman, more than two degrees above average in December and part of January.
La géologie, une science plus que passionnante … et diverse