The Arctic Thread - Page 2 - Weather Spotlight - 33andrain Jump to content

Recommended Posts

On 9/29/2018 at 8:29 AM, Blessed Weather said:

Every picture tells a story, and whilst the headline is that the Arctic Basin minimum Sea Ice Extent this fall is the 3rd lowest since records started in 1979, the graph highlights how the minimum level has been on a downward trend over the period 1979 - 2018. This from Zack Labe:

 

Sea ice extent is currently the third lowest on record for the inner Arctic Ocean basin. Each line is one year of @NSIDC daily data over the satellite era [purple (1979) to white (2017)]. 2018 is shown in red.

 

 

My apologies - I wasn't paying sufficient attention and hadn't noticed that the tweet above WAS NOT saying that the absolute minimum sea ice in 2018, when compared with the absolute minimum for other years, was the 3rd lowest on record. Zach Labe chose to compare the sea ice extent some days after the 2018 minimum with other years ON THAT DATE. Hence the "3rd lowest" statement. I'm disappointed in the tweet and I'm disappointed I didn't spot this.

 

This post from Arctic Sea Ice News a few days ago gives clarity about this years minimum and the provisional 2018 ranking of 6th lowest:

 

Arctic sea ice extent arrives at its minimum

September 27, 2018

On September 19 and 23, Arctic sea ice appeared to have reached its seasonal minimum extent for the year, at 4.59 million square kilometers (1.77 million square miles). This ties 2018 with 2008 and 2010 for the sixth lowest minimum extent in the nearly 40-year satellite record. 

Please note that this is a preliminary announcement. Changing winds or late-season melt could still reduce the Arctic ice extent, as happened in 2005 and 2010. NSIDC scientists will release a full analysis of the Arctic melt season, and discuss the Antarctic winter sea ice growth, in early October.

 

Table - 12 lowest Minimum Sea Ice Extents 1979 to date: 

 

Arctic Sea Ice Minimum Extent 2018.jpg

 

Link to report: https://nsidc.org/arcticseaicenews/category/analysis/

 

  • Like 2

Share this post


Link to post
Share on other sites
On 10/13/2018 at 5:59 PM, Bring Back 1962-63 said:

EXTREMELY SLOW ICE BUILD UP - THE RE-FREEZE HAS HARDLY BEGUN

We can examine the circulation patterns and the other reasons for the unusually slow build up on here.  For the Siberian coast to be ice free and for the entire eastern Arctic to be navigable in mid October is almost unheard of. I hope to bring some better news before too long but I am really concerned about this delayed re-freeze.  David ? 

SNIPPED (charts removed and much of the text to save space)

 

Hi David...

 

Just to let you know that I registered for the portal and that this is my first post

 

MIA

  • Like 3

Share this post


Link to post
Share on other sites

Hi MIA, a big welcome to 33andrain.  Malcolm @Blessed Weather and I will be doing a lot of cross-posting on both forums, especially our Arctic and Teleconnection thread posts. You'll find it really friendly on "33".  There are two great young hosts who set up this forum and they both post on here quite regularly. They are Geoff @33andrain and Pat @NJwxguy78.  They provided all the facilities for us to create and build up the portal with full editing rights. Zac @Snowy Hibbo introduced us to this forum back in March and he created the Teleconnections thread on here. You'll recognise several other names on here too. I shall look forward to your posts and some interesting debates - Malcolm and I both really want to encourage that and we all have the Arctic as one of our favourite topics. David :) 

  • Like 3

Share this post


Link to post
Share on other sites
5 hours ago, Midllands Ice Age (UK) said:

 

Hi David...

 

Just to let you know that I registered for the portal and that this is my first post

 

MIA

Welcome to 33andrain! 

  • Like 2

Share this post


Link to post
Share on other sites

I don't think any of this is a surprise. For those of us who have watched the arctic with concern since 2007 or so, the rate of overall melt is now on an increasingly steep gradient and we appear to have passed a tipping point that is likely to leave us in an arctic almost ice free in high summer in a worryingly short space of future time. This can only be bad news for the Greenland ice sheet and consequently sea levels.

 

What will it do for the weather across the populated northern hemisphere continents? It surely has to help increase the rate of extreme weather events, of energy release that will upset traditional passage of the jet and pressure patterns across the pole. What will happen to cloudiness in the region given warm water and far reduced albedo? Beyond my knowledge but I'd be interested to find out. Will the gulf stream be substantially affected? Are we likely to see more SSWs?

 

It's a worrying but also fascinating topic. Of all the regions in the world being affected by climate change the arctic has to rank No 1 for potential global impact down the line.

 

 

  • Like 3

Share this post


Link to post
Share on other sites

Thanks to those for posting this information about the Arctic and sea ice. It is very concerning. This can influence jet stream patterns and PV disruptions. While the presence of more water increases storms, the presence of warmer waters increases high pressure (blocking). Not sure which is going to dominate, but it certainly makes a recipe for extreme weather events. Since Arctic sea Ice is instrumental in monitoring global temps, this is certainly not good. 

  • Like 4

Share this post


Link to post
Share on other sites
On 10/21/2018 at 10:46 AM, Bring Back 1962-63 said:

 

@jules216  - I must also welcome you on to "33" as part of our expanding group of UK members on here. I understand from Tams @Tamara that you have been discussing AAM and the torques with her and she has been assisting you.  I also noted your recent query back on the UK forum on one of the (at least) 3 Arctic threads there (I just cross-posted my post from here updating Arctic temps and SSTs onto the Arctic ice and stats thread (I hope we can keep it to just one thread here on "33" - otherwise it gets very confusing and some excellent posts may well be missed - the new UK forum thread is not easy to locate in the search options).   Anyway, I see that no one has answered your query which was: 

 

"Not sure if this belongs here, but why is Arctic warming so much more then Antarctica, what would be the scientific explanation to that, or any link  to a research document?"

 

This "Arctic" thread also covers Antarctica, Greenland, global ice and glacial ice.  I did a post on page one of this thread on Antarctica and this included a comparison between that continent and the Arctic. The long answers are explained in that post.  The short answer or main reason for the differences is that the Arctic is mostly an open ocean surrounded by land while Antarctica is a landmass surrounded by an ocean. Antarctica loses almost all it's sea ice each summer but much less of it's land ice.  Only the outer edges of the continent rise slightly above freezing in the summer months and much of the interior stays well below. Overall, there has hardly been any "net" ice loss from Antarctica.  The southern oceans have warmed up but what this has down is created a lot more moisture which has led to big increases in snowfall all the year around - even the "desert" areas near to the South Pole have seen increased snowfall. Much of the ice sheet is over 3km thick.  The increased snowfall has caused the ice sheet to become more mobile.  The Antarctica glaciers have sped up. When they reach the sea they break off making for dramatic headlines with huge ice shelves floating out into the ocean.  This is seized upon by those at the extreme end of the global warming debate stating that we are losing ice down there at a rapid pace. This is actually not true.  Total ice there has changed very little during the last 30 years and probably for much longer than that.  West Antarctica has lost a small amount but this is made up for by the east making a small gain - the drier east seeing the greatest increases in snowfall.  

 

This is not to say that longer term climate change and global warming will eventually reduce Antarctica ice but right now that continent is helping to slow down the net global ice loss.  There are a number of research teams and scientists down there conducting some very sophisticated monitoring and together with the latest satellite data (one new satellite now exclusively monitors that region) we should obtain some vital data to assess more precisely what is going on.    David :) 

SNIPPED (charts and much of the text removed to save space)

thank you for welcoming me in, it is a place where I can learn a lot and also thanks to Tamara, Snowy Hibbo and Catacol who are trying to explain some of the most complicated processes with a simple jargon, more like GSDM for dummies :) . My question re Antarctica arose from this GLOSEA 5 seasonal anomaly and the deep blue colors that engulf Antarctica and I wanted to know why is there such a strong anomaly 

43787703_248171602539660_7931275213692469248_n.png

  • Like 4

Share this post


Link to post
Share on other sites

I figure it might be useful, for reference, to jot down the sequence of events (with approximate timing) that have taken the Arctic to where it is now from where it was at the end of the previous century.

 

Here's what I have currently. Due to a very busy mind, I may have missed out or misrepresented some developments (and the timing of some is open to some debate), in which case please let me know and I'll add or amend them accordingly :).

 

- (2007-2012) Warmer Arctic temperatures coupled with favourable melt-season weather patterns in more years than not, resulting in significantly lowered sea ice coverage.
- More exposed ocean brings about an even warmer Arctic in all but the summer season, reducing sea ice thickening during the freezing season.
- Warming reaches a magnitude at which it starts to significantly weaken the Oct-Apr polar jet, permitting higher amplitude (larger N-S span) Rossby wave formation.
- These higher amplitude waves simultaneously transport more warmth and moisture into the Arctic, and draw more cold air out of it.
- This further disruption and reduction of freezing season cold leads to additional anomalous open waters and relatively high temperatures, perhaps aided by changes in the ocean currents due to the effects of the anomalously large solar-ocean energy transfer.

- (2013 onward) The summer season sees a destructive feedback (relative to sea ice melting) in the form of increased cloudiness as a result of the extra moisture input from the anomalously exposed areas of ocean surface. However, while this reduces solar-driven melt, it doesn't inhibit ocean-driven melt or that from mechanical action relating to storms - and there are signs that the additional moisture plus more amplified planetary waves can support more frequent and stronger storms than in previous decades. As a result, we see the Arctic resisting new record minimums of sea ice extent, but the overall thickness of the ice remains near or at record-low levels.

- (2016 onward) The autumn-early winter Arctic undergoes transformation toward a climate that is more oceanic than continental, resulting in a more resilient divide of high latitude cold pooling between the adjacent continents, raising the potential for the predominant cyclonic circulation (polar vortex) to establish over one or both of these regions at a location further from the Arctic Ocean than usual. Such a displaced vortex provides another means for large-scale transport of warm air into the Arctic and of cold air out of it - and so the situation constructively feeds back on itself as we're currently being unfortunate enough to witness.

 

 

Phew. The situation's also become noticeably more complicated with time!

  • Like 4

Share this post


Link to post
Share on other sites

HURRICANE FLORENCE AND ARCTIC SEA ICE....AND MUCH MORE

 

I intend to cross- post this onto the Countdown to Winter 2018-19 thread,  the main Hurricane thread (not the archived Florence thread), the Arctic thread, the Teleconnections thread and the Climate Change thread as it relates to all these threads. Why, I hear you ask? - I'll explain in a minute.  I was reading through some Arctic related papers and presentations when I came across this fascinating YouTube presentation which I have just placed into the Research Portal.  This had a lead in headline of "Hurricane Florence and Arctic Sea Ice" but the presentation is entitled:  "How Global Warming and Arctic Ice Melt Intensify Hurricanes" but it covers a lot more than that and includes implications for the North Am climate and the upcoming CONUS winter.

 

I found it on the Arctic Sea  Ice Blog which I read from time to time.  Last month Real Time News interviewed Dr Jennifer Francis, the well known research professor at Rutgers University's Institute of Marine and Coastal Sciences in New Jersey (since 1994).  I'm sure that some of you will be familiar with her work. She specialises in atmospheric sciences.  She has produced many papers and features in a number of presentations. In recent years she has been focusing in studying climate change, Arctic amplification and ice loss and how this impacts on extreme weather events. In 2015 she was the one who first suggested that global warming and Arctic sea ice loss was starting to effect the jet stream. The initial reaction from a few fellow meteorologists and climatologists was to dismiss her ideas and research findings by claiming that the jet stream had started to behave differently around 15 to 20 years earlier and prior to the more recent ice loss. Like many new theories, the "establishment" often take a while to realise that there is far more too them than they first thought or perhaps "wanted to believe"!. Part of the controversy was simply due to the type of theory which went right into the heart of the global warming and climate change debate. I have always tried to take a very balanced and open minded approach to this subject that has such extreme and polarised views. Jennifer is very concerned about the impacts of global warming but all that she has been doing is researching how the changes which have been happening (however much they are due to human induced activities or natural variability or, as I tend to believe a combination of the two) are impacting on the global weather patterns and what might we expect going forward. 

 

This presentation which is pitched at an "easy to understand" level covers the following: 

  • It starts off with that cool Atlantic pool which has form off the southern tip of Greenland several years ago and how this has impacted on the Gulf stream.
  • This is developed into an explanation of how this was partly responsible for the unusually positioned HP ridge which steered hurricane Florence into the east coast.
  • Then this is also related to hurricane Harvey and Sandy.
  • A more detailed explanation of the weaker and changing Jet Stream follows.
  • Next the Californian droughts are explained (much longer term changes than those created by El Nino and La Nina episodes) 
  • She distinguishes between natural processes in the warming Pacific and unnatural processes like the warm NPAC and the ice loss in the Bering Sea and off Alaska..
  • You will see how this impacts on the whole N Am weather patterns and further afield.
  • The final topic covers Super Typhoon Mangkhut and its intensity, excessive rainfall and the storm surge impacts are largely put down to climate change.

 

Overall, this presentation is rather more than a simple learner's guide and the charts and visuals are really well explained. Just click on the title below for a link to the Research Portal entry:

 

How Global Warming and Arctic Ice melt Intensify Hurricanes - YouTube Presentation   From there, you will find a quick link to the 13 minute presentation.

 

I will be adding more of Jennifer's presentations to the portal in the coming weeks. There is a more detailed one on the changing Jet Stream which I will review on the Teleconnections thread and some which are more specific to the Arctic and I'll review those on that thread.  David :)  

  • Like 4

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×