Wobbles in the Barriers: Arctic Oscillation (4)

By: Dr. Ricky Rood , 4:22 PM GMT on October 14, 2013

Wobbles in the Barriers: Arctic Oscillation (4)

This is a continuation of my series on the Arctic Oscillation / North Atlantic Oscillation. Links to background material and previous entries are at the end.

In the last entry I suggested that if you were on a bridge overlooking a swiftly flowing creek then you would notice that twigs floating in the water did not move across the current. They are carried downstream along the edge of the current. The purpose of that comparison was to demonstrate how fast-moving, concentrated flows have the effect of isolating one side of the creek from the other. This is true in the creek, and it is also true about jet streams in the atmosphere.

One way to understand the Arctic Oscillation is to think of it as the variation of an atmospheric jet stream. For the Arctic Oscillation the jet stream of interest is the southern edge of vortex of air that circulates around the North Pole (see previous entry). Air inside the vortex often has characteristics different from air outside it. Intuitively for the Arctic, there is colder air on the side toward the pole. If you look at trace gases, like ozone, they are different across the edge of the vortex. The takeaway idea is that the edge of the vortex is a barrier. It’s not a perfect barrier, but the air on one side is largely separated from the air on the other side. In this blog, I describe the difference between a strong and a weak vortex – which is the same as the difference between the positive and negative phases of the Arctic Oscillation and the North Atlantic Oscillation.

Figure 1: This figure is from the point of view of someone looking down from above at the North Pole (NP). Compare this perspective to Figure 1 in previous blog. This represents a strong, circular vortex centered over the pole, which encloses cold air, represented as blue. The line surrounding the cold air is the jet stream or the edge of the vortex.

Figure 1 shows an idealized schematic of the North Pole as viewed from above. This is the strong vortex case, when there is exceptionally low pressure at the pole. Low pressure is associated with counterclockwise rotation in the Northern Hemisphere. This direction of rotation is called cyclonic. This strong vortex case is the positive phase of the Arctic Oscillation. During this phase, the vortex aligns strongly with the rotation of the Earth, and there are relatively few wobbles of the edge of the vortex – the jet stream. I drew on the figure two points, X and Y. In this case, the point X is hot and the point Y is cold. It is during this phase when it is relatively warm and moist over, for example, the eastern seaboard of the United States.

Figure 2 compares a strong vortex and a weak vortex. In both cases, the circulation around a central point is counterclockwise or cyclonic. However, in the weak vortex case, the vortex does not align as strongly with the rotation of the Earth and there are places where the edge of vortex extends southwards. The vortex appears displaced from the pole; it is not centered over the pole.

Figure 2: Examples of a strong, circular vortex and a weak, more wavy vortex. See text for a more complete description.

Whether the vortex is stronger or weaker is determined by the atmospheric pressure at the pole. In the winter, an important factor that determines the circulation is the cooling that occurs at polar latitudes during the polar night.

What determines the waviness or wobbles at the edge of this vortex? The structure at the edge of vortex is strongly influenced by several factors. These factors include the structure of the high-pressure centers that are over the oceans and continents to the south of jet stream. One could easily imagine a strong high-pressure center over, for example, Iceland, pushing northward at the edge of the vortex. This might push a lobe of air characteristic of the middle latitude Atlantic Ocean northward. Since the edge of the vortex is something of a barrier, this high-pressure system would distort the edge of the vortex and, perhaps, push the vortex off the pole. This would appear as a displacement of the vortex and its cold air over, for example, Russia. If the high grew and faded, then this would appear as wobbles of the vortex.

Other factors that influence the waviness at the edge of the vortex are the mountain ranges and the thermal contrast between the continents and the oceans. The impact of mountains is easy to understand. Returning to the creek comparison used above, the mountains are like a boulder in the stream. The water bulges around and over the boulder; the air in the atmosphere bulges around and over the mountain ranges. The Rocky Mountains in the western half of North America are perfect examples of where there are often wobbles in the atmospheric jet stream.

Figure 3: This figure is from the point of view of someone looking down from above at the North Pole (NP). This represents a weak, wavy, wobbly vortex displaced from the pole. The vortex encloses cold air, represented as blue. The line surrounding the cold air is the jet stream or the edge of the vortex. (definition of vortex)

Figure 3 shows an idealized schematic of the North Pole as viewed from above. This is the weak vortex case, when the low pressure at the pole is not as low as average and the pressure is much higher than the strong vortex case of Figure 1. This weak vortex case is the negative phase of the Arctic Oscillation. During this phase, the alignment of the vortex with the rotation of the Earth is less prominent, and there are wobbles of the edge of the vortex – the jet stream. In this case, the point X is cold and the point Y is hot. It is during this phase where it is relatively cool and dry (but potentially snowy) over, for example, the eastern part of the United States.

These figures help to explain the prominent signal of the Arctic Oscillation discussed in the earlier entries (specifically, this blog). That is, when the vortex is weak and wobbly, then there are excursions of colder air to the south and warmer air to the north. This appears as waviness and is an important pattern of variability - warm, cold, warm, cold.

The impact of the changes in the structure of edge of the vortex does not end with these persistent periods of regional warm and cold spells. The edge of the vortex or the jet stream is also important for steering storms. Minimally, therefore, these changes in the edge of the vortex are expected to change the characteristics of how storms move. Simply, if the edge of the vortex has large northward and southward extensions, then storms take a longer time to move, for example, across the United States from the Pacific to the Atlantic Oceans. In the positive phase of the Arctic Oscillation they just whip across. In the negative phase, the storms wander around a bit. A more complete discussion of this aspect of the role of the Arctic Oscillation will be in the next entry. (Note use of dramatic tension and the cliffhanger strategy of the serial.)

r

Previous entries:

Barriers in the Atmosphere
Behavior
Definitions and Some Background

August Arctic Oscillation presentation

CPC Climate Glossary “The Arctic Oscillation is a pattern in which atmospheric pressure at polar and middle latitudes fluctuates between negative and positive phases.”

Comments will take a few seconds to appear.

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 957 - 907

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30Blog Index

957. JohnLonergan
 Quoting 948. Daisyworld:I'm really pleased to see this concept of standing up to the denial machine is starting to catch on around the world. I posted a plea in Michelle Schlachta's blog last week (WU admin; sensitivethug) for the WU policy makers to consider adopting similar policies as Popular Science and the LA Times. Of course, there was much mocking, but I'm still holding out hope that they'll implement something.Ha! :-D "Google Galileos!" Love it!Paraphrasing Carl Sagan:"They laughed at Galileo, they laughed at Newton, they laughed at Einstein, they also laughed at Bozo the Clown"
Member Since: June 27, 2012 Posts: 0 Comments: 4589
955. Daisyworld
 Quoting 954. Neapolitan:I read that, and loved it. Especially where you noted (as you have before) that were you to spend the day posting anti-weather nonsense in Masters' blog, you'd doubtless be laughed at and derided, then pretty quickly banned for a while, if not forever. So why people are allowed to continue to do so here and in Masters' forum is beyond me.Following yours and Xulonn's link to WtD, I also learned that the Sydney Morning Herald has also taken the bold stand against the Manufactured Doubt industry:"Climate change deniers or sceptics are free to express opinions and political views on our page but not to misrepresent facts. This applies to all our contributors on any subject. On that basis, a letter that says, 'there is no sign humans have caused climate change' would not make the grade for our page..."Here's hoping that science reporting in journalism is starting to wake up...
Member Since: January 11, 2012 Posts: 6 Comments: 968
954. Neapolitan
 Quoting 948. Daisyworld:...I'm really pleased to see this concept of standing up to the denial machine is starting to catch on around the world. I posted a plea in Michelle Schlachta's blog last week (WU admin; sensitivethug) for the WU policy makers to consider adopting similar policies as Popular Science and the LA Times. Of course, there was much mocking, but I'm still holding out hope that they'll implement something...I read that, and loved it. Especially where you noted (as you have before) that were you to spend the day posting anti-weather nonsense in Masters' blog, you'd doubtless be laughed at and derided, then pretty quickly banned for a while, if not forever. So why people are allowed to continue to do so here and in Masters' forum is beyond me.
Member Since: November 8, 2009 Posts: 4 Comments: 15124
953. ScottLincoln
 Quoting 951. tramp96:Many feel that GW is theory regardless both theory and science have been proven wrong many times in throughout history.The things that "many feel" are just not grounded in actual scientific fact.
Member Since: September 28, 2002 Posts: 5 Comments: 3521
952. Daisyworld
 Quoting 951. tramp96:Many feel that GW is theory regardless both theory and science have been proven wrong many times in throughout history.Again, science is not a popularity contest. Nor is it governed by any number of suppositions or human emotions/feelings. Whatever others may "feel" about the reality of human-induced climate change, it does not change how mathematics work, the basic laws of nature, or of the overall functioning of the cosmos.
Member Since: January 11, 2012 Posts: 6 Comments: 968
950. Daisyworld
 Quoting 949. tramp96:Yeah so if you don't agree with it call it a lie andcensor it. Just change the name to Weather Regime.By blocking discussion via engagement in frivolous arguments, circular questions, and posting blatant lies, it is the climate change denialists and the Manufactured Doubt industry who are engaging in censorship.It is difficult to have a discussion of any value unless there is a common ground in reality. Science is not a popularity contest, and the value of ideas in science is measured by metrics such as usefulness, intellectual integrity, testability, and critical thinking criteria. Teaching science such as meteorology and climatology in general must be able to provide the learner with concepts and ideas that are held in high esteem by those who are active in the fields. Anything less, and the learner will be deceived about the proper identification and utilization of the science topics.
Member Since: January 11, 2012 Posts: 6 Comments: 968
948. Daisyworld
 Quoting 943. Xulonn:"Watching the Deniers" is an excellent website from Australia, founded and managed by a gentleman named Mike Marriott. It has a heavy focus on climate denialism in Australia, where the new PM is an avowed denialist.I don't remember if it has been ever been discussed here at the WU/CC blog, but if so I missed it. I consider it one of the best sources on the internet that I have found on the subject. I was particularly pleased to see this new rule at that blog that was put in place last week (We can only wish that WU might become so enlightened!):I'm really pleased to see this concept of standing up to the denial machine is starting to catch on around the world. I posted a plea in Michelle Schlachta's blog last week (WU admin; sensitivethug) for the WU policy makers to consider adopting similar policies as Popular Science and the LA Times. Of course, there was much mocking, but I'm still holding out hope that they'll implement something.Quoting 945. Neapolitan:"...You lack relevant qualifications or expertise in a highly technical discipline -- most would be "Google Galileo's" (99.99%) lack qualifications in climate science. They may have impressive qualifications in other fields (engineering, finance, economics) but the truth is they lack the decades of training in the field. Just as nobody can become an overcome expert in neurosurgery from reading Wikipedia, so you can't "Google" the web and become an overnight expert on a highly complex area of science..."Ha! :-D "Google Galileos!" Love it!
Member Since: January 11, 2012 Posts: 6 Comments: 968
946. Xulonn
 Quoting 945. Neapolitan:Xulonn, hope you don't mind, but I wasn't sure when you'd return, so I removed all the character markup from that great comment to make it more readable:Thanks, Jim. Back to the computer during my lunch break. I copied your cleaned up copy back into my post with the corrections - it's definitely worth reading twice!I simply cannot understand why the WU programmers won't revise their code and use and/or recognize the same character code set in preview and post. It appears that they use the Alt # set for the preview and the HTML "&" prefix characters for the "submit an edit" posting subroutine. Characters shows correctly in the initial preview and post, then when you edit a perfectly fine post and preview it, it still looks o.k. However when you submit and post the edit the WU website coding substitutes "&" HTML error codes for the ASCII codes in the post.David
Member Since: Posts: Comments:
945. Neapolitan
Member Since: November 8, 2009 Posts: 4 Comments: 15124
944. schwankmoe
 Quoting 925. ScottLincoln:Here's a good first place to start, Doug:1. Look at the scale of the Antarctic Sea ice.2. Look at the range of the 2 standard deviations.3. Compare #1/#2 to the same on plots for Arctic sea ice.4. Look at trends in Antarctic extent growth (caution... 2D only) compared to Arctic extent loss.What you will find is that, even if cooling was behind the Antarctic growth, Arctic sea ice loss is overwhelming the growth around Antarctica. By a factor of more than 3x. So even if it were consistent with cooling, the warming is overwhelming it, which is not "balancing out." So the reason climate scientists spend more time talking about the Arctic is because it's changes are more substantial, and they are strong enough to offset changes in the Antarctic.Of course we have since found that it is not cooling that is causing increases to sea ice in the Antarctic.never mind that Antarctic land ice loss dwarfs Antarctic sea ice gains and the former is largely responsive for the latter. all records are not equal. a marathoner besting the record by 2 seconds is not the same as a sprinter besting the 100 meter dash record by 3. one is a squeaker, the other would be completely insane.
Member Since: Posts: Comments:
943. Xulonn
Member Since: Posts: Comments:
941. Xulonn
 The earthquake was at 57km depth, under an epicenter about 55km away, just offshore in the Gulf of Chiriqui. Probably felt a lot more in our regional capitol of David, the second largest city in Panama. The dark line is the Costa Rica border.
Member Since: Posts: Comments:
940. JohnLonergan
 Quoting 939. Xulonn:Quote of the day! (Did you make that one up, John?)No all credit goes to the author of the article(Richard Telford), but I will "borrow" it.Remember:Don't abuse your eyes,Use your eyes, plagiarize.Tom Lehrer
Member Since: June 27, 2012 Posts: 0 Comments: 4589
939. Xulonn
 Quoting 938. JohnLonergan:Watts and commentators at WUWT are already attacking the paper with the accuracy and precision of a blind sniper using reindeer droppings for ammunition.Quote of the day! (Did you make that one up, John?)
Member Since: Posts: Comments:
938. JohnLonergan
 “Unprecedented” – skeptic flypaper“Unprecedented”Nothing seems to attract the inverted love of fake climate sceptics like the word ‘unprecedented’. Perhaps they don’t like to be reminded that our shared climate trajectory is into unexplored and potentially dangerous space. Perhaps because they can often make the trivial claim that the unprecedented event is not really unprecedented because it was warmer/wetter in the CarboniferousMiller et al (2013) used this sceptic bait-word in the title of their paper published online yesterday: “Unprecedented recent summer warmth in Arctic Canada”. Miller et al radiocarbon date moss and lichen emerging from beneath glaciers on Baffin Island and find that some are over 40,000 years old. An alarming result implying that the glaciers are now smaller than at any time in the last 40,000 years, and by extension, probably since the Eemian, the last interglacial, ~120,000 years ago. Watts and commentators at WUWT are already attacking the paper with the accuracy and precision of a blind sniper using reindeer droppings for ammunition.The press release for the paper is characteristically useless, not linking to the actual paper. Unfortunately, despite the interest the media interest the paper was likely to generate, it has not been made open access. This might explain why Watts and commentators at WUWT have obviously not read the paper.Watts argues that the moss now being exposed by the retreating glaciers may have been previously uncovered and reburied. The paper explicitly discounts this possibility.Our field observations, and the presence of extensive vegetation-free regions surrounding most retreating ice caps [Locke and Locke, 1976] indicate that most long-dead tundra plants exposed by ice recession are rapidly removed from the landscape by wind-blown winter snow or by run-off during the melt season.Read More at Musings on Quantitative Palaeoecology
Member Since: June 27, 2012 Posts: 0 Comments: 4589
936. Patrap
 Event Time2013-10-26 22:34:34 UTC2013-10-26 17:34:34 UTC-05:00 at epicenter2013-10-26 17:34:34 UTC-05:00 system timeLocation8.376°N 82.910°W depth=12.9km (8.0mi)Nearby Cities4km (2mi) W of Finca Blanco Numero Uno, Panama11km (7mi) NNW of Puerto Armuelles, Panama35km (22mi) WSW of La Concepcion, Panama52km (32mi) W of Pedregal, Panama215km (134mi) SE of San Jose, Costa Rica
Member Since: July 3, 2005 Posts: 449 Comments: 140144
934. Xulonn
 Really strong earthquake just now felt here in Boquete, Panama. By far the strongest i have felt in my 1.5 years here, and nearly as strong as the worst I felt in my 50 years Northern in California. No damage or fallen objects at my house, but severe rolling and shaking for about 30 seconds.Whether is was a moderate close one or a big one far away, I don't know yet. Edit: lots of comments on local expat blog - felt by many, potted plants moved, but no damage reports here yet.Time of quake: 27 October 2013 at 15:41 UTCNot showing up yet at USGS, but it's Sunday.Last quake - a couple of weeks ago - was a local one at magnitude 4.1 with an epicenter 1km from my house. I live on the flank of the dormant Volcano, the highest mountain in Panama. The lack of attention on the internet might indicate that this one was local - and stronger than the last local quake.
Member Since: Posts: Comments:
933. JohnLonergan
 Quoting 932. Xulonn:You're quicker than me at finding a rebuttal to the spittle-laced rantings of Tisdale, John. Thanks!But please, stop already with the interesting, logical, and valid points and links. I have other things to accomplish today, and you are giving me too much fodder for my procrastination!It's simple, Sou is 14 hours ahead of us, so that's the last place I check at night.
Member Since: June 27, 2012 Posts: 0 Comments: 4589
932. Xulonn
 Quoting 930. JohnLonergan:Sou has already destroyed the Willard the Rat/Tisdale foolishness:You can see from the graph that 1990 was the highest year to date at the time.Bob Tisdale doesn't understand graphs and lies about them to boot, a common failing among deniers.You're quicker than me at finding a rebuttal to the spittle-laced rantings of Tisdale, John. Thanks!But please, stop already with the interesting, logical, and valid points and links. I have other things to accomplish today, and you are giving me too much fodder for my procrastination!
Member Since: Posts: Comments:
931. JohnLonergan
 Quoting 928. Birthmark:Which is what makes RSS "tragic", imo. Even UAH shows warming and it's measuring the same thing as RSS...and agrees with the surface temperature data sets. I've been watching RSS (and UAH) struggling to overcome their problems. UAH, to my surprise since it's Christy and Spencer, has done a better job.But Spencer and Christy have had a lot of help from their peers, everything they publish is gone over with a fine tooth comb. Several times they have been forced to correct their work.
Member Since: June 27, 2012 Posts: 0 Comments: 4589
930. JohnLonergan
 Quoting 926. Birthmark:Why would you believe a satire website like that? Was The Onion website down or something? Seriously, Sideshow Tony has been consistently wrong on the facts, on the interpretations of the facts, and been demonstrated to be a serial liar of the most transparent variety. It has got to be satire.Here are four of the major data sets:Only the tragic RSS, which doesn't measure surface temperature anyway, shows anything other than cooling.Since Sideshow Tony is only using a short time period that rarely shows statistically significant warming, he is cherry picking. Allow me to return the favor. Ask Sideshow Tony why he isn't aware that *all* temperature data sets show warming since late 2007.If we actually look at climate, which is defined as thirty years, we see that the warming has progressed fairly evenly.Finally, you might ask Sideshow Tony why temperature hasn't declined precipitously, given the low solar activity of the last few years, the negative PDO, and the preponderance of La Ninas for the last fifteen years? What's keeping the surface temperature so warm?Sou has already destroyed the Willard the Rat/Tisdale foolishness:Bob Tisdale hides the warming and tries out a conspiracy theory at WUWT> One graphic tells it all:You can see from the graph that 1990 was the highest year to date at the time.Bob Tisdale doesn't understand graphs and lies about them to boot, a common failing among deniers.
Member Since: June 27, 2012 Posts: 0 Comments: 4589
929. Xulonn
 Quoting 923. Cochise111:The only time we have warming in the past fifteen years is when data is adjusted. The models being used currently have proven one thing: they are all flawed and should be disallowed to make climate predictions.Embellishing your role as a "Google Galileo" I see. (More about that descriptive term in another comment.) So you are saying that inaccurate raw data should be used?? Actually, Tisdale's jousting with Tamino is interesting, and I await the next round. (In spite of Tisdale's request to avoid such rhetoric, the comments after his post are quite vapid and sophomoric.)In the meantime, the Law of Conservation of Energy is still valid, and the heat content of the earth system continues to rise at a phenomenal rate due to the greenhouse effect. Tisdale seems to base his squabble with Tamino on the "movement" of heat in the atmosphere and hydrosphere, but ignores the constant addition of more heat to those spheres (particularly the hydrosphere with the continuing addition of heat to the deep ocean.) If it were not for this heat accumulation, Tisdale might have a point, but right now he's merely fighting in the sandbox of AGW/CC denialism while the hydrosphere, atmosphere, cryosphere, and geosphere continue to accumulate heat and the biosphere suffers irreversible changes. p.s., Thanks for that denialist post - my typical rigorous attempt to understand and rebut it lead to an interesting website that discusses AGW/CC denialism with respect to the denialist community's popular "Galileo" meme, which I shall comment on separately.
Member Since: Posts: Comments:
927. ScottLincoln
 Quoting 926. Birthmark:Only the tragic RSS, which doesn't measure surface temperature anyway, shows anything other than cooling.Technically, UAH is lower-troposphere as well.
Member Since: September 28, 2002 Posts: 5 Comments: 3521
925. ScottLincoln
 Quoting 921. PensacolaDoug:And their ice cover is setting all time high records right now. I'm not aledging this disproves AGW. However, if it was setting all time record lows, we would sure be hearing about it from the AGW crowd.Here's a good first place to start, Doug:1. Look at the scale of the Antarctic Sea ice.2. Look at the range of the 2 standard deviations.3. Compare #1/#2 to the same on plots for Arctic sea ice.4. Look at trends in Antarctic extent growth (caution... 2D only) compared to Arctic extent loss.What you will find is that, even if cooling was behind the Antarctic growth, Arctic sea ice loss is overwhelming the growth around Antarctica. By a factor of more than 3x. So even if it were consistent with cooling, the warming is overwhelming it, which is not "balancing out." So the reason climate scientists spend more time talking about the Arctic is because it's changes are more substantial, and they are strong enough to offset changes in the Antarctic.Of course we have since found that it is not cooling that is causing increases to sea ice in the Antarctic.
Member Since: September 28, 2002 Posts: 5 Comments: 3521
922. MisterPerfect
 BOEM schedules central gulf lease sale for March 2014 HOUSTON 10/25/2013 By OGJ editorsThe US Bureau of Ocean Energy Management reported it will conduct Lease Sale 231—to auction off oil and gas tracts in the central Gulf of Mexico planning area—on Mar. 19, 2014, in New Orleans.Thirty-nine million acres will be made available offshore Louisiana, Mississippi, and Alabama, encompassing 7,508 unleased blocks covering 39.4 million acres. The locations of the blocks range 3-230 miles offshore in 9-11,115 ft of water. BOEM said the proposed lease sale could net 1 billion bbl of oil and 4 tcf of natural gas in production.“The sale sets fiscal terms that will continue to ensure fair return to taxpayers and includes conditions to encourage diligent development as well as ensure an appropriate balance of orderly resource development with protection of the human, marine, and coastal environments,” BOEM said.This is the fourth lease sale to be held in the 2012–17 Outer Continental Shelf leasing program (OGJ Online, Nov. 8, 2012). During Central Gulf Lease Sale 227, held in March 2012, industry only bid for 4.4% of the blocks offered with a total high bonus of \$1.2 billion (OGJ Online, Mar. 20, 2013).November 2012’s Western Gulf Lease Sale 229 saw 13 companies submit bids for 116 of 3,873 blocks offered, accounting for just 3% of 20.75 million acres. Apparent high bids totaled \$133.7 million during that sale (OGJ Online, Nov. 29, 2012).In August, BOEM’s Western Gulf Lease Sale 233 received 61 bids for 53 tracts covering just 301,006 acres out of nearly 21 million available acres. High bids totaled \$102,351,712—the smallest amount so far in the leasing program (OGJ Online, Aug. 28, 2013).http://www.ogj.com/articles/2013/10/boem-schedule s-central-gulf-lease-sale-for-march-2014.html
Member Since: Posts: Comments:
 Quoting 1035. maxcrc:The map doesn't show the brutal anomalies in the Antarctica, where all records have been broken, with the warmest September on record for large swaths of the Continent with insane monthly anomalies as high as 8C.And their ice cover is setting all time high records right now. I'm not aledging this disproves AGW. However, if it was setting all time record lows, we would sure be hearing about it from the AGW crowd.Record winter ice cover in AntarcticaMatthew Denholm The Australian October 24 2013WINTER sea ice cover in the Antarctic has grown to its largest extent since satellite records began in the late 1970s, defying most climate models and muddying the waters of the global warming debate. The latest data from NASA's satellites shows the winter sea ice cover around the frozen continent reached a record 19.47 million sq km last month. That beats last winter's 19.44 million sq km -- itself a record.According to NASA, it is 3.6 per cent higher than the average maximum between 1981 and 2010, with the sea ice cover in Antarctica growing at 1.5 per cent a decade.The data runs contrary to the projections of many climate-change models. It also contrasts with observations of this year's Arctic summer minimum sea ice extent, which America's National Snow and Ice Data Centre says was about 30 per cent below levels seen in the early 1980s.Scientists appear unable to definitively explain the phenomenon, but believe increasingly strong winds in Antarctica and an increase in rain and snow on the Southern Ocean are the most likely factors. Some fear the findings may fuel climate-change scepticism, given that sea ice is said to be the "canary in the coalmine" of global warming.However, experts in the field warn the increase in Antarctic sea ice extent is far outweighed by the decline in sea ice in the Arctic."You add the two together -- a strong decline in the Arctic and the weakly positive increase in the Antarctic -- then you're still getting a strong net decline globally," said Guy Williams, sea ice specialist with the Hobart-based Antarctic Climate and Ecosystems Co-operative Research Centre."It's a common myth and should be dispelled: that if sea ice disappears one season in the Arctic it magically reappears in the next season in the Antarctic. That couldn't be further from the truth. They are two completely different (climate) systems, responding to (global) warming in different ways."A growing body of research suggests the main reason for the increase in Antarctic sea ice is an increase in the force of polar winds. It shoves the sea ice together, causing ridging and creating thicker, longer lasting ice and promoting sea ice growth.There appears to be no definitive explanation for the increased wind intensity, although research papers have blamed everything from the ozone hole and increased carbon dioxide in the atmosphere to natural variations.Dr Williams said another factor promoting sea ice extent in the Antarctic was an increase in rain and snow over the Southern Ocean. The resulting fresher layer of water acted to protect ice and ice-producing conditions from warmer mid-level water that would otherwise melt ice and hinder its production.Adding to the complexity, parts of the Antarctic, such as the Bellingshausen Sea, are experiencing a rate of increase in ice-free conditions greater than in the regions of largest ice decline in the Arctic. Others, such as the Ross Sea, have had a significant increase in ice extent, of about 5 per cent each decade over the past 30 years.An important unanswered question is whether the volume of ice, as opposed to its extent, is increasing or decreasing. Dr Williams said this was unknown but it was hoped the next generation of satellites would give the answer.He warned the factors promoting the growth of Antarctic sea ice cover may not hold the upper hand for ever. "We expected the Antarctic to be stable relative to the Arctic but at some point the trigger will come and we'll see a reduction," he said. "If you image the hypothesis that as you blow out (the sea ice from the continent) you make it thinner, then it becomes more volatile and vulnerable to more rapid retreat." - See more at: http://www.theaustralian.com.au/national-affairs/p olicy/record-winter-ice-cover-in-antarctica/story- e6frg6xf-1226745602870#sthash.w9jfX4Po.dpuf
Member Since: Posts: Comments:
920. JohnLonergan
 Eli Rabbet muses on science denial then and now in this morning's post, Lewandowsky Invariance.Eli writesThe Theory of Relativity became established science within twenty years. Some recognized its importance and correctness quickly, for example, Max Planck. On the other hand, the theory remains distasteful to many, mostly not scientists. Exploration of that distaste is instructive and there is no better place to start than Einstein's take "This world is a strange madhouse. Currently, every coachman and every waiter is debating whether relativity theory is correct. Belief in this matter depends on political party affiliation.” and Anti-relativists were convinced that their opinions were being suppressed. Indeed, many believed that conspiracies were at work that thwarted the promotion of their ideas. The fact that for them relativity was obviously wrong, yet still so very successful,And further...One of the first things that jumps out is how the witches of denial cooked relativity and climate change in the same kettle. Wazeck observes that the physicists who opposed Einstein, and it did get personal, were those who were fearful of being sidelined by the shift of the field to a more mathematical approach. In the same way, the professional opposition to climate change science was rooted in the observational climatologists seeing a threat to their work from the climate modeling community, the Tim Balls, the William Grays, the Pat Michaels, of the world, and the regional climatologists, the Roger Pielke Sr.'s...In conclusion, one must acknowledge that science denial is the same from every point of observation both in time and in space. Eli formulates this as Lewandowsky Transform of Denial Invariance. Read the full essay at Rabbet Run >>
Member Since: June 27, 2012 Posts: 0 Comments: 4589
918. Patrap
 finbliz Climate ChangeSea Level RiseSea levels have been rising. That is a fact. The key question is, at what rate will sea levels rise in the future? Sea levels can rise due to two primary causes:1. Land based ice melts or slides into the ocean 2. Sea temperatures rise and sea water expandsNASA JPL"There are 5-6 meters worth of sea level in the Greenland ice sheet, and 6-7 meters in the West Antarctic Ice Sheet, while the much larger East Antarctic Ice Sheet is probably not vulnerable to widespread melting in the next century. Many hundreds of millions of people live within that range of sea level increase, so our inability to predict what sea level rise is likely over the next century has substantial human and economic ramifications. Earth system scienceEarth system science is the study of how scientific data stemming from various fields of research, such as the atmosphere, oceans, land ice and others, fit together to form the current picture of our changing climate. Climate scientists separate factors that affect climate change into three categories: forcings, feedbacks, and tipping points.Forcings: The initial drivers of climate.1.Solar Irradiance. Solar radiation is the source of heat for planet Earth. Scientists also use evidence from proxy measurements, such as sunspot counts going back centuries and ancient tree rings, to measure the amount of sun that reaches Earth's surface. The sun has an 11-year sun spot cycle, which causes about 0.1% of the variation in the sun's output. 1 The solar cycle is incorporated into climate models.2.Greenhouse gas emissions. Since the industrial revolution, concentrations of greenhouse gases such as carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) have risen in the atmosphere. Burning fossil fuels such as coal, oil and gas has increased the concentration of atmospheric carbon dioxide (CO2) from 280 parts per million to 393 parts per million.2 These greenhouse gases absorb and then re-radiate heat in Earth's atmosphere, which causes increased warming.3.Aerosols, dust, smoke, and soot. Very small airborne particles come from both human and natural sources and have various effects on climate. Sulfate aerosols, which result from burning coal, biomass, and volcanic eruptions, tend to cool the Earth. Other kinds of particles such as black carbon have a warming effect. The global distribution of aerosols is being tracked from the ground and from satellites.
Member Since: July 3, 2005 Posts: 449 Comments: 140144
917. FLwolverine
 Quoting 907. auburn:Please keep personal disputes out of Dr. Ricky Roods blog. Thanks All.That wasn't a personal dispute. It was a comment on how far someone had gone over to the dark side.
Member Since: January 6, 2013 Posts: 3 Comments: 2761
916. JohnLonergan
 New from Horatio Algeranon – Horatio Algeranon’s perversification of Neil Young(as per special suggestion of Doc Snow)Mockt man lyingby the sleight of the statsWith the cherries rolling by,Loony tune linkingfrom the blog of the WattsWhere the postings do deny,Godwin rippingRichard Alley and factsWith the Morner paper flies,Mockt man vyingBy the sight of the flatsWith the de-light in his eyes.Don’t let it bring you downIt’s only strawmen burning,Find someone who’s turningAnd you will come around.Blind man runningthrough the blogof the RightWith “THE ANSWER” in his hand,Come on downto the river of shiteAnd you can really understand,Red lights flashingthrough the windowon the screen,Can you hear the scientists moan?Science lyingin a gutter, from a Dane,Who is bjorn again in tone.Don’t let it bring you downIt’s only strawmen burning,Just find someone who’s turningAnd you will come around.Don’t let it bring you downIt’s only strawmen burning,Find someone who’s turningAnd you will come around.
Member Since: June 27, 2012 Posts: 0 Comments: 4589
914. JohnLonergan
 Quoting 911. Birthmark:Using the same chart as Bastardi, but eliminating the years 2007-2012, we can put this "Arctic recovery" into its proper place.We can see easily that 2013 was hands down the lowest Arctic Sea Ice minimum when compared to any year prior to 2007. Some "recovery." lolThe arctische pinguin's volume graph shows it tooLink
Member Since: June 27, 2012 Posts: 0 Comments: 4589
913. Xulonn
 Quoting 912. StSimonsIslandGAGuy:It's been below normal for the past 3 days where I live. That proves global warming is bunk!Hey, I just made the strongest denier argument ever! Now it's time to get back on the side of truth and science.I see from Dr. Masters blog that you are one of the originals here at WU - welcome to the climate blog and AGW/CC denialist slugfest.
Member Since: Posts: Comments:
910. Xulonn
 Quoting 890. iceagecoming:You can keep your religion, as well! I'll stay with the facts.Nothing personal, iceagecoming, but actually, I don't have a religion. I'm neither a Catholic nor affiliated with a church of any kind. However, I found it interesting that this arm of the Catholic church declared that AGW/CC denial is a sin. It appears that they understand and accept the reality of climate science's conclusions about AGW/CC - e.g., "the facts." This is in alignment with what Dr. Masters teaches us, and what the vast majority of the scientific community supports. I will consider any valid critique of any part of climate science, but I haven't seen anything here yet that has not, or cannot be, debunked - except for minor and/or inconsequential details.
Member Since: Posts: Comments:
909. ScottLincoln
 Quoting 905. Birthmark:You should ask Climate Oaf Bastardi why the Earth hasn't cooled appreciably, with all these negative factors? What's kept us from temperatures like those we saw in the early 20th century? Of course, you won't ask, nor will you address that issue. Neither will Bastardi. Propagandists are like that. ;)The Arctic Sea Ice is still extremely low, despite a summer that was near perfect to prevent melting.Bastardi can stuff it. He's an ignoramus.That's the interesting thing. Bastardi, again, has his entire post hinge on one fact that isn't really a fact at all. He wrote tons of fluff and hyperbole that when condensed down into an argument, is basically this:Arctic sea ice is going down, but Antarctic sea ice is going up, which is because the earth always somehow balances out regions of cooling with warming.Let's keep in mind for a second that Bastardi is a scientist who studies the atmosphere who presumably took the same coursework as the rest of us and has been around long enough to not make trivial mistakes.Now, lets talk about the obvious issues in his logic:1) Antarctic sea ice is increasing, but ~1/3 the rate of Arctic sea ice losses. They are not "balancing out." And the southern oceans are gaining heat at the same time.2) We know that the earth doesn't magically "balance out" with warming/cooling, because we've had changes in climate before. Isn't that one of the big skeptic arguments... climate's changed before? There is this whole ice age thing that I didn't even know was being actively debated. That's what happens when the earth has an energy imbalance. It doesn't "balance out."3) We know the earth isn't "balancing out" because temperature datasets for the atmosphere/oceans/ice, including proxies for temperature, are showing a global warming trend. Overall, the planet is accumulating heat. That isn't what happens when it is "balancing out."Once this main concept from his discussion is shown to be silly hyperbole, the rest pretty much disintegrates. He really needs to stick to weather where he tends to have a somewhat better track record.
Member Since: September 28, 2002 Posts: 5 Comments: 3521
907. auburn (Mod)
 Please keep personal disputes out of Dr. Ricky Roods blog. Thanks All.
Member Since: Posts: Comments:

Viewing: 957 - 907

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30Blog Index