Heet in Siberië

Alles wat betrekking heeft op het buitenlands weer. Tropische stormen, orkanen, etc.
Plaats reactie
Karel
Berichten: 3189
Lid geworden op: 31-07-1978

Re: Heet in Siberië

Bericht door Karel » 01-07-2020 13:17

Ted, inderdaad is Верхоянск (Verhojansk) op 29 juni met een maximum van 24,6 graden ook volgens ogimet uit deze hittegolfperiode in Siberië gevallen. Het station ligt iets ten oosten van het hittegebied. Daar duurt de hittegolf nog voort. Een iets westelijker en noordelijker gelegen station Dzalinda dus volgen.

Afbeelding
Afbeelding
Afbeelding

Ted
Berichten: 4011
Lid geworden op: 31-03-1984

Bericht door Ted » 01-07-2020 15:16

.
Laatst gewijzigd door Ted op 13-02-2021 14:46, 1 keer totaal gewijzigd.

Karel
Berichten: 3189
Lid geworden op: 31-07-1978

Re: Heet in Siberië

Bericht door Karel » 03-07-2020 20:04

De volgende dag was in Dzalinda de hitte naar het zuiden verdreven. Overal ten noorden van 65N is het daar sterk afgekoeld gisteren.
bronnen:http://www.ogimet.com/ en https://meteoinfo.ru/mapsynop

Afbeelding

Afbeelding


Sebastiaan
Berichten: 12235
Lid geworden op: 31-12-1977

Re: Heet in Siberië

Bericht door Sebastiaan » 09-07-2020 21:57

https://twitter.com/mikarantane/status/ ... 3867288576
Tweets zeggen genoeg. Helaas kan ik ze niet plakken.

Sebastiaan
Berichten: 12235
Lid geworden op: 31-12-1977

Re: Heet in Siberië

Bericht door Sebastiaan » 09-07-2020 21:59

Plaatje van de tweets
Je hebt niet voldoende permissies om de bijlagen van dit bericht te bekijken.

Sebastiaan
Berichten: 12235
Lid geworden op: 31-12-1977

Re: Heet in Siberië

Bericht door Sebastiaan » 09-07-2020 21:59


Karel
Berichten: 3189
Lid geworden op: 31-07-1978

Re: Heet in Siberië

Bericht door Karel » 10-07-2020 08:20

Bedankt Sebastiaan, Copernicus goede Europese bron voor informatie over klimaat c.a.

Ook het Oeral gebied gaat nu meedoen met de Siberische warmte aangestuurd door een koud Scandinavië.
bron:https://meteoinfo.ru/mapsynop

Afbeelding

Sebastiaan
Berichten: 12235
Lid geworden op: 31-12-1977

Re: Heet in Siberië

Bericht door Sebastiaan » 12-07-2020 18:30

Achtergrond door Judah

Impacts

Certainly, one of the biggest if not the biggest weather news story of the summer so far has been the high-pressure system/heat dome that setup over Siberia in June leading to record breaking high temperatures and wildfires across Siberia. The exceptional warmth has caused sea ice to melt at a record pace in the Laptev Sea adjacent to Siberia and has contributed to an overall acceleration of sea ice melt for the entire Arctic basin over the past several weeks. That high pressure system that sat over Siberia for much of June has now drifted into the Central Arctic centered near the North Pole.

Therefore, the circulation pattern in the Central Arctic is likely to be very different from recent Julys. The circulation in the Central Arctic has been dominated by low pressure resulting in relatively cloudy, cool weather. So even though Arctic sea ice at the end of the winter was at or near record low extent no new record annual minimums have been observed since 2012 because summer low pressure in the Central Arctic slowed sea ice melt. However, at a minimum for the first half of July, the Central Arctic will be dominated by high pressure favoring relatively sunny and warm weather, which is conducive to accelerated sea ice melt. There does seem to be a higher probability that the sea ice minimum in 2020 will be lower than recent summers and may even challenge the record low of summer 2012.

The high pressure drifting towards the North Pole does seem to be contributing to cooler weather across Northern Europe as the Arctic high-pressure locks in low pressure/troughing and relatively cool temperatures for Europe. The Arctic high is predicted to dissipate for the second half of July, and if correct, will likely result in warming temperatures. However, the opposite seems to be true for North America. The models are predicting that the high heights/pressure that started over Siberia and are now over the North Pole will eventually drift towards the Aleutians. Ridging near the Aleutians will force troughing along the North American west coast with more ridging and a new heat dome over the interior of the North American continent potentially resulting in a very warm and dry July for large parts of the US and Canada.

Given that these slow moving summer high pressure systems/heat domes seem to be in the news with greater frequency in recent years, I thought to share a simplistic discussion how climate change in general but Arctic change in particular may be contributing to an increasing frequency of these nearly stationary heat domes that result in record high temperatures, drought and wildfires. Though this explanation is not limited to heat and drought extremes but also extreme rainfall and flooding as well. This is not a topic that I have researched in any detail personally, as my focus is on the winter season, but the ideas that I present below and the influence of Arctic change on Northern Hemisphere summer weather is nicely reviewed in Coumou et al. 2018.

Weather systems are steered across the globe by the Jet Stream in a steady west to east direction. Jet streams arise in each hemisphere, in part, due to temperature differences between the poles and the equator, a margin known as a temperature gradient. If the temperature difference between the equator and poles is high, then the gradient is strong resulting in a strong Jet Stream. As that temperature gap closes, the gradient is then weakened, and the Jet Stream slackens.

Typically, there is a smooth and gradual change in temperature from the equator to the poles with temperatures hottest near the equator and coldest near the poles. Under these typical conditions there is one Jet Stream that circumnavigates the hemisphere in between the equator and the poles across the mid-latitudes where the temperature gradient or differential is greatest (see Figure i). However, over the past two decades the Arctic has warmed two to three times faster than the rest of the globe, weakening the temperature gradient between the North Pole and the equator that could potentially disrupt the natural behavior of the Jet Stream.

The general weakening of the temperature gradient between the equator and the North Pole is happening in both the winter and the summer, therefore the North Pole-equator temperature gradient has grown weaker all year round. However, the gradient between the North Pole and the northern edges of the continents during the summer is actually strengthening. The greatest warming is transpiring on this northern continental edge due to accelerated melt of both spring snow cover and sea ice along the continental edges, where darker surfaces absorb more sunlight. In contrast in the Central Arctic sea ice persists reflecting much of the incoming sunlight. Therefore, the temperature differential is increasing between the Central Arctic and the northern continental edges, strengthening the gradient supportive of an active Jet Stream. Further south, with the northern edges of the continents warming faster than the central or southern edges of the continents, the temperature gradient across the mid-latitudes has slackened, which is not supportive of an active Jet Stream. Finally, with warming relatively evenly distributed across the mid and lower latitudes, the temperature gradient between the equator and the mid-latitudes is comparable to previous decades supportive of an active Jet Stream.

Ultimately, the strengthened gradient in the high latitudes (between the North Pole and the northern edges of the continents), the weakened gradient from the northern to the central and southern edges of Eurasia and North America, and the relatively unchanged gradient between the mid-latitudes and the equator could contribute to a split in jet streams during the summer—one to the north, and the other to the south.

This split Jet Stream allows weather systems to move more slowly across the Northern Hemisphere. In between the two streams the normal west to east winds slacken or even disappear completely, causing weather systems to become trapped or stationary between the two or split jet streams (see Figure ii). When weather systems become stationary, it is favorable for these weather systems to strengthen and create extreme weather. Over the past several summer we have observed nice examples of split jet streams with trapped weather systems in between including heat domes. Favorable positions for these heat domes have been western North America, Europe and Siberia resulting in extreme heat, drought and wildfires. This summer, the most impressive heat dome has been located over Siberia, but one existed earlier this summer over Northern Europe and another is predicted over the interior of North America. But it isn’t just heat domes but also low pressure with extreme rainfall that can become trapped. A current example is persistent low pressure in Far East Asia leading to flooding rains in Japan.

Gerben
Berichten: 16631
Lid geworden op: 08-09-2013

Re: Heet in Siberië

Bericht door Gerben » 12-07-2020 22:19

Zo bijzonder is de Laptevzee niet opgewarmd. De normaal voor de zuidelijke Laptevzee ligt rond 5 graden. Die temperatuur is daar lokaal bereikt.
Ik vind de kou in Zuid-Afrika meer imponerend. Dinsdag/woensdag tot zo'n 15 graden onder de normaal

Afbeelding
Laatst gewijzigd door Gerben op 13-07-2020 16:55, 1 keer totaal gewijzigd.

Plaats reactie