# 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.”

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##### 807. Patrap
 Kate Sheppardkate.sheppard@huffingtonpost.comClimate Scientist Campaigns Against Ken Cuccinelli In Virginia Governor's RacePosted: 10/17/2013 11:45 am EDT | Updated: 10/17/2013 2:57 pm EDTWASHINGTON -- Climate scientist Michael Mann has teamed up with NextGen Climate Action in a new web video posted last week, urging Virginians to vote against Republican Ken Cuccinelli in the governor's race.Mann, a former University of Virginia professor, has been the subject of Cuccinelli's anti-climate science attacks. Beginning in April 2010, Cuccinelli attempted to use his position as the state attorney general to subpoena Mann's records and email correspondence, in order prove that the scientist's research constituted "fraud" against taxpayers in the state. The effort dragged on for two years and cost UVA hundreds of thousands of dollars, but was ultimately unsuccessful.Mann, who is now the director of the Earth System Science Center at Pennsylvania State University, campaigned against Cuccinelli in the state in July. Now he's taking to the web, accusing the attorney general of "trying to attack the science of climate change by attacking me." Mann's entry into the Virginia campaign marks an unusual step for a climate scientist."One would like to think that the attorney general would be representing the people of his state. Unfortunately, Ken Cuccinelli chose to spend the taxpayers' money, forced the University of Virginia to spend \$600,000 defending itself, and untold millions of dollars mounting this attack," Mann says in the video, posted last Tuesday. "Those millions of dollars could have been used to help Virginians already start to cope with the impacts that we're already seeing of climate change.""Climate change is here. We have to do something about it now," Mann says. "There's nothing you can do that's more important than voting and encouraging your friends and family and everyone else you know to vote."
Member Since: July 3, 2005 Posts: 430 Comments: 131147
##### 806. Patrap
 HP has its own Climate Change page nowUnited States Urges Flexibility In New Global Climate DealQuick Read | Comments (150) | 10.22.2013The Amazon Rain Forest Is Drying OutQuick Read | Comments (632) | NatureClimate Change Has A New Enemy: Super CoralsQuick Read | Comments (56) | 10.22.2013The World's Oceans Will Be Dramatically Different In 100 YearsQuick Read | Comments (368) | 10.21.2013
Member Since: July 3, 2005 Posts: 430 Comments: 131147
##### 805. ncstorm
 Quoting 789. Patrap:In a community, people look out for one another. Funny no one ever brings any Science to explain da warming from the er, "there's no warming crowd"?Only innuendo and well,ill will for those on the side of "Science".Fresca ?Sip, ahhhhhhhhhhhhhhhh'you know, chugging a fresca after every insult isnt healthy.."The next time you grab a Mountain Dew, Squirt, Fanta Orange, Sunkist Pineapple, Gatorade Thirst Quencher Orange, Powerade Strawberry Lemonade or Fresca Original Citrus, take a look at the drink's ingredients. In Mountain Dew, brominated vegetable oil is listed next-to-last, between disodium EDTA and Yellow 5. These are just a sampling of drinks with BVO listed in their ingredients, which is required by the FDA. The most popular sodas – Coca-Cola and Pepsi – do not contain BVO."
Member Since: August 19, 2006 Posts: 13 Comments: 16298
 Quoting 803. schwankmoe:you gave us one post by John, correct? and the point of contention is his use of "I", correct? if he used the word "he" you couldn't have cared less. so yes, you're throwing a fit over one word in one post. you've made it clear what you think that one word in one post shows. I think it's pretty thin evidence to deny another person's humanity. got anything more substantive? no? then okay. What color is the sky of that world you're living in?
Member Since: July 25, 2006 Posts: 2 Comments: 765
##### 802. ncstorm
 Quoting 799. PensacolaDoug:Are you incapable of comprehending something you read?That's not what happened at all. If you follow the series of posts, it appears that JL answered as Nea.they trying so hard to put out that fire..LOL.comic relief..here's a scenario you guys can use:"well maybe JL was having a sandwich and left the refrigerator door open and while returning to the kitchen he saw on his laptop by the refrigerator where dealwithit responded to nea and decided to jump in the conversation but accidently dropped mustard on the "I" key but as he went to wipe it off he mistakenly typed it instead"..case solved..
Member Since: August 19, 2006 Posts: 13 Comments: 16298
##### 801. Patrap
Member Since: July 3, 2005 Posts: 430 Comments: 131147
##### 800. BaltimoreBrian
 Quoting 790. PensacolaDoug:To know me is to love me!
##### 798. ncstorm
 Quoting 796. Neapolitan:Oh, I'm sorry; I must have misread your question; I only explained my WU ban history because I thought you asked:Oh, wait--you did ask that. Now I'm confused...Anyway, I do believe I've had all the silly innuendo and baseless accusation I can take for the evening, so unless you've got something to discuss on the science side of things, count me out of the rest of this futile exercise...nah..I'll just wait for an explanation..have a good night Nea..carry on the fight..
Member Since: August 19, 2006 Posts: 13 Comments: 16298
##### 797. ncstorm
Member Since: August 19, 2006 Posts: 13 Comments: 16298
##### 794. ncstorm
 Quoting 792. Neapolitan:Ooh, pick me! Pick me!FWIW, I hadn't been banned here until last fall, roughly about the time the mods became public. Since then, I've been given a time-out on several occasions--six? seven? eight?--with the most recent being just two or three weeks ago (and I'm still unsure why that was). If nothing else, that tells us the ongoing meme that AGW "believers" don't get banned here is simply nonsense.Great comment! [pat-pat-pat]she said PERMANENTLY!! not temp bans..so WRONG..try again..LOL
Member Since: August 19, 2006 Posts: 13 Comments: 16298
##### 793. FLwolverine
 Quoting 790. PensacolaDoug:To know me is to love me!Fortunate for you.
##### 792. Neapolitan
 Quoting 791. ncstorm:nope..Skyepony has told me in a public conversation on Dr. Masters blog with her and auburn that Mods do not have access to IP addresses but only when they banned people permanently and admin gives the mods the IP addresses to them..so unless she has banned Nea recently with another handle then she would be saying mods do have access to IP addresses and that would be her way of verifying Nea doesnt have multiple handles which is another whole issue now..hmmm..who has been banned recently from the AGW side??Ooh, pick me! Pick me!FWIW, I hadn't been banned here until last fall, roughly about the time the mods became public. Since then, I've been given a time-out on several occasions--six? seven? eight?--with the most recent being just two or three weeks ago (and I'm still unsure why that was). If nothing else, that tells us the ongoing meme that AGW "believers" don't get banned here is simply nonsense.Quoting 786. Birthmark:It's a pretty good group here, Doug. They deserve their pats on the back.Great comment! [pat-pat-pat]
##### 791. ncstorm
 Quoting 774. DonnieBwkGA:Skyepony is a moderator and would know. That settles the issue.nope..Skyepony has told me in a public conversation on Dr. Masters blog with her and auburn that Mods do not have access to IP addresses but only when they banned people permanently and admin gives the mods the IP addresses to them..so unless she has banned Nea recently with another handle then she would be saying mods do have access to IP addresses and that would be her way of verifying Nea doesnt have multiple handles which is another whole issue now..hmmm..who has been banned recently from the AGW side??
Member Since: August 19, 2006 Posts: 13 Comments: 16298
 Quoting 782. FLwolverine:Funny how no one wants to be Dougie.To know me is to love me!
Member Since: July 25, 2006 Posts: 2 Comments: 765
##### 789. Patrap
 In a community, people look out for one another. Funny no one ever brings any Science to explain da warming from the er, "there's no warming crowd"?Only innuendo and well,ill will for those on the side of "Science".Fresca ?Sip, ahhhhhhhhhhhhhhhh'
Member Since: July 3, 2005 Posts: 430 Comments: 131147
##### 788. luvtogolf
 Quoting 774. DonnieBwkGA:Skyepony is a moderator and would know. That settles the issue.Ya right.
##### 787. luvtogolf
 Quoting 785. PensacolaDoug:You guys never tire of patting each other on the back.It's a bit weird I'd say.
##### 786. Birthmark
 Quoting 785. PensacolaDoug:You guys never tire of patting each other on the back.It's a pretty good group here, Doug. They deserve their pats on the back.
Member Since: October 30, 2005 Posts: 7 Comments: 5469
 You guys never tire of patting each other on the back.
Member Since: July 25, 2006 Posts: 2 Comments: 765
##### 784. Xulonn
 Quoting 727. ncstorm:...I actually plussed ScottLincoln's post for the first time...Very courageous on your part, NC. Scott is a scientist who usually posts comments based on hard science - something that you have often indicated that you don't "believe" in.
##### 783. RevElvis
 Nebraska approves climate-denying study; scientists refuse to conduct it A study on the impact of climate change on Nebraska, recently approved by the state, may not be carried out — because its own scientists are refusing to be a part of it.The problem, according to members of the governor-appointed Climate Assessment and Response Committee, is that the bill behind the study specifically calls for the researchers to look at “cyclical” climate change. In so doing, it completely leaves out human contributions to global warming.At a discussion yesterday, the Omaha World-Herald Bureau reports, Barbara Mayes, a meteorologist with the National Weather Service, pointed out that “cyclical” isn’t even a scientific term.And it’s not just a misuse of language: State Sen. Beau McCoy, who added the word to the bill, is a known climate denier. “I don’t subscribe to global warming,” McCoy said during an earlier debate about the legislation. ”I think there are normal, cyclical changes.”At the meeting, a number of scientists stood up to declare that they refused to take part in the study:Salon.com
Member Since: September 18, 2005 Posts: 30 Comments: 1085
##### 782. FLwolverine
 Funny how no one wants to be Dougie.
##### 781. FLwolverine
 Quoting 779. goosegirl1:And I have no idea who I am, so if you ferret it out shoot me message.That's ok. You can be me, because I'm really Daisyworld.
##### 780. RevElvis
 Study shows humans are jerks You're a selfish jerk. It's nothing personal - it's just probably true. I'm likely a selfish jerk, too. And this is why our descendants are going to be dealing with the impacts of climate change: Because whatever we do about it now, it isn't going to help any of us much, and it might be an inconvenience. And, as a group, humans are terrible about making sacrifices, especially ones we won't benefit from.I know it's not fun to face this. But there's good evidence. A group of scientists just published a paper on an experiment that modeled how good people are at averting future climate change, Bryan Walsh reports at TIME. The researchers put people in groups and gave each person \$55. The participants had 10 chances to invest that money, in small increments, into a climate fund. If, as a group, they invested \$165, they'd all get \$60. And, oh yah, would have "averted climate change."No one participant could reach the \$165 goal by themselves, so everyone needed to trust that others would invest, too. And there was also another condition. Some groups would get the reward the next day. Some would get it seven weeks later. Some wouldn't get the reward in money, but in oak trees, planted to sequester carbon.How'd they do? Badly. Even among the groups that had to wait just one day to recoup their investment, three out of 10 failed the cross the threshold and avert climate change. None of the groups who were rewarded with trees made it.Grist.org
Member Since: September 18, 2005 Posts: 30 Comments: 1085
##### 779. goosegirl1
 Quoting 761. schwankmoe:no, i'm pintada.And I have no idea who I am, so if you ferret it out shoot me message.
##### 778. goosegirl1
 Quoting 750. JohnLonergan:Yep, they're hereGee whiz, I miss all the fun. I have been busy moving and barely take time out to sleep, let alone blog. But somehow, I have turned into Nea... or Naga... or wait a minute, was it FLWolverine, or... oops, I just blew my cover!
##### 777. Xandra
 Quoting 773. JohnLonergan:[...] When historians of the year 2200 write the history of climate change, is anyone going to come out worse than Fred Singer?"Those who spread the misinformation and outright lies of the climate denial industry, are useful idiots of some of history’s coldest and greediest killers."- Peter Sinclair(Click for larger image)Source
 Quoting 773. JohnLonergan:Today's Candidate for worst Man on Earth: When historians of the year 2200 write the history of climate change, is anyone going to come out worse than Fred Singer?This is Al Gore commenting as JohnLonergan on a post i just made ...Sorry John, if the denier industry gets its way (and some (e.g. pintada) think they have already won), there will be no historians in 2200.
##### 775. schwankmoe
 Quoting 767. PensacolaDoug:Did you even read the post? 629?Because your post is demonstrably false.of course i read it. you cited one post by john, where he used 'I' instead of 'he'.that's it. one post of his, one word at issue. "I". if he had used "he" you wouldn't have gone on this crusade at all.now if you think one word in one post makes john not a real person, that's your belief, but it's some weak tea to deny someone's humanity with.
Member Since: October 18, 2005 Posts: 0 Comments: 797
##### 773. JohnLonergan
 Today's Candidate for worst Man on Earth: Singer: I Don't Like Saying They're Fraudulent, But...Fred Singer, in an interview in the San Diego Union Tribune, says he doesn't like to call the IPCC "fraudulent," but they're "fraudulent":Q: How are policy makers, journalists and the public, who are not scientists, supposed to filter out who’s right and who’s wrong? Singer: The IPCC has a way of ignoring inconvenient facts. It’s actually fraudulent but we don’t like to use that term, not because we’re scared of being sued but because all it does it get the other side’s back up.Singer also says "there has been no rise in temperature for some 17 years," which is downright false: HadCRUT4 shows 0.11 ± 0.06 °C of warming over the last 17.0 years (uncertainty is 2σ calculated via OLS). GISS data has it at 0.15 ± 0.06 °C.Of course, it's also false because it ignores the strong ocean warming over that time.There's also this bit of obfuscation:Singer: Well, it depends on where you start. If you start from the last ice age, 18,000 years ago, it certainly is much warmer. If you start 1,000 years ago, from the medieval climate warming, then it’s slightly cooler. If you start from the (Middle) Ice Age or let’s say around 1700 or so, then it is definitely warmer. So it has been warming. The earth is warming, not steadily, but in jumps.When historians of the year 2200 write the history of climate change, is anyone going to come out worse than Fred Singer?
Member Since: June 27, 2012 Posts: 0 Comments: 4048
##### 772. JohnLonergan
 Report: Wildfires & Air Pollution, A Hidden HazardAcross the American West, climate change has made snow melt earlier, spring and summers hotter and fire seasons longer. One result has been a doubling since 1970 of the number of large wildfires raging each year. And depending on the rate of future warming, the number of big wildfires in western states could increase as much as six-fold over the next 20 years.Beyond the clear danger to life and property in the burn zone, smoke and ash from large wildfires produces staggering levels of air pollution, threatening the health of thousands of people, often hundreds of miles away from where these wildfires burn. The critical component of a fire’s smoke is so-called “fine particle” air pollution, which is a direct threat to human health even during relatively short exposures. And the pollution levels produced by these wildfires are extremely high: high enough to potentially increase mortality in susceptible populations, like the elderly and those with heart conditions, and increase emergency room visits for asthma sufferers and others with respiratory conditions. This analysis looks at air pollution from some of the largest wildfires in the West over the past 12 years.Read more at ClimateCentral Full Report PDF
Member Since: June 27, 2012 Posts: 0 Comments: 4048
##### 771. Patrap
 I am Spartacus
Member Since: July 3, 2005 Posts: 430 Comments: 131147
##### 770. JohnLonergan
 Quoting 766. FLwolverine:Ok ok. I wanted to be JohnL anyway!I'm honored.(And I am the Tsar of all the Russias)
Member Since: June 27, 2012 Posts: 0 Comments: 4048
##### 769. JohnLonergan
 From the BOM(Australia):The Remainder of 2013The year-to-date temperature anomaly is currently so large that mean temperatures during the remaining three months of 2013 only need to be slightly above average for the year to set a new calendar year record. An anomaly of just +0.24 °C for the remainder of the year (i.e. October to December) will result in 2013 equalling the record held by 2005. Zero anomalies for the last three months of the year will result in 2013 finishing as the second-warmest year on record.It also remains possible that the 12-month mean temperature record will be equalled or broken again before the end of the year, for the periods ending October, November and/or December.The Bureau’s latest seasonal outlook indicates that both maximum and minimum temperatures are most likely to be above average over most of Australia. The outlook for warmer-than-average temperatures over the remainder of the year is consistent with the Bureau’s knowledge of background temperature trends, and the well-above-average sea surface temperatures that currently surround Australia. Australian temperatures are now on average more than 1 °C warmer than during the 1950s.Source
Member Since: June 27, 2012 Posts: 0 Comments: 4048
##### 768. Xandra
 Comment: Let's confront the reality of climate change Our fire seasons are starting earlier, lasting longer and have more days of extreme fire weather. We can no longer ignore the effects of climate change, writes Bruce Esplin. By Bruce Esplin AMWhen it comes to climate change there are increasing signs the future has already arrived.As Victorian Emergency Services Commissioner for 10 years, and a senior emergency management officer for over 20 years, I am increasingly concerned about what I’ve seen.Emergency Services workers are at the front line of climate change impacts. To me, climate change is not a political issue. It’s a health and safety issue - for the emergency services and for the whole community.In Australia we used to have what seemed to be, on average, a 7 to 10 year cycle for extreme events. Now we are seeing extreme events so much more frequently. Now it’s every two to three years. Our fire seasons are starting earlier and lasting longer with more days of extreme fire weather.When you consider what has happened all around Australia in the last decade it’s quite terrifying. It’s not just Australia, though.I don’t doubt that the reporting of natural disasters is more comprehensive, or that more and more people are living closer to danger - for example the urban spread/urban-rural interface issue in relation to bushﬁre risk. However, there’s no doubt in my mind that our climate is changing and that is already having an impact on the frequency and the scale of events.I’m not somebody who would argue that any single event is a direct result of climate change. But I think the pattern, if you’re prepared to look objectively, is quite scary.One of the things that worries me about Australians is our tendency to stick our head in the sand and think ‘it’s not going to happen to me’ or ‘it’s a problem for a future generation’.In my mind and surely in the scientists’ minds, we don’t have that luxury.If we don’t do something now, both the problem and the consequences on future generations will be just too horrific to think about.Read more >>
 Quoting 760. schwankmoe:you have one post where john used "I" instead of "he". one single different word used in one post.Did you even read the post? 629?Because your post is demonstrably false.
Member Since: July 25, 2006 Posts: 2 Comments: 765
##### 766. FLwolverine
 Quoting 761. schwankmoe:no, i'm pintada.Ok ok. I wanted to be JohnL anyway!
##### 765. cyclonebuster
 Quoting 763. Birthmark:Cooling...briefly. Then back to the warming.How briefly? So we might be better off not to deflect it and just let it hit us...
##### 764. Birthmark
 Quoting 762. Patrap:Can a brotha get a JB tweet ?I don't know. Have you tried squeezing him?
Member Since: October 30, 2005 Posts: 7 Comments: 5469
##### 763. Birthmark
 Quoting 752. cyclonebuster:So if this were to hit us in 2032 would it cause warming or cooling??LinkLink....Cooling...briefly. Then back to the warming.
Member Since: October 30, 2005 Posts: 7 Comments: 5469
##### 762. Patrap
 Can a brotha get a JB tweet ?
Member Since: July 3, 2005 Posts: 430 Comments: 131147
##### 761. schwankmoe
 Quoting 759. FLwolverine:Well, I'm really pintada so I'm going to plus my (his?) post 100 times. Anyone who is waiting for a valid unbiased scientific opinion that AGW is not happening and won't be a problem, is waiting in vain. Nobody is going to come along to save us from our own actions.no, i'm pintada.
Member Since: October 18, 2005 Posts: 0 Comments: 797
##### 760. schwankmoe
 Quoting 734. PensacolaDoug:In my comment #724, I specifically referred to my actual knowledge of sock puppets. That's not a guess or assumption on my part based on a single word in a single comment;My contention is not based on a single word in a comment. There ya go again...you have one post where john used "I" instead of "he". one single different word used in one post.
Member Since: October 18, 2005 Posts: 0 Comments: 797
##### 759. FLwolverine
 Quoting 756. pintada:This is JohnLonergan posting via Neapolitan to say:Compromise? So if you and I put our heads together and determine that we can agree that global warming will only be 3 degrees centigrade you think that will have any effect on the truth?The science will not change, and reality will not change because I (see that, I used the word i, so i must be birthmark) let someone lie.Well, I'm really pintada so I'm going to plus my (his?) post 100 times. Anyone who is waiting for a valid unbiased scientific opinion that AGW is not happening and won't be a problem, is waiting in vain. Nobody is going to come along to save us from our own actions.
##### 758. JohnLonergan
 CHINA: GRAY IS THE NEW REDThough the Chinese Academy of Science has sent S. Fred Singer and The Heartland Institute's other ersatz ambassadors packing from Peking, nature and centrally planned central heating have conspired to leave behind a monochrome reminder of the existential pleasures of unmitigated coal burning
Member Since: June 27, 2012 Posts: 0 Comments: 4048
##### 757. JohnLonergan
 IPCC’s New Estimates for Increased Sea-Level RiseRecently released sea-level rise findings from IPCC project greater increases than earlier forecast, but continuing uncertainties persist, and drawing direct comparisons with past estimates is difficult.Estimates for higher sea-level in coming decades are one of the major “take home” messages from the newly released IPCC report.Projected sea-level rise had been a particularly controversial aspect of the 2007 IPCC Fourth Assessment Report, with many scientists decrying the absence of modeling of dynamic ice sheet movements and arguing that models had underestimated historical sea-level rise. As a result, many had expected treatment of sea-level rise to be the focus of much attention on the new report, and that has been the case.Understanding why sea-level rise now is forecast to be greater, and why substantial uncertainties remain, requires examining the different causes of sea-level rise and the different ways of estimating future sea-level rise using both physical models and evidence from Earth’s geologic past.Global sea levels have increased fairly steadily over the past 130 years, with some acceleration evident over the past few decades. The figure below shows observations both from tide gauges (from 1880 to 2009) and satellites (1993 to 2013), with measurement uncertainty reflecting incomplete coverage of tide gauges shown in grey.......Latest Sea-Level Rise Estimates Still Too Conservative?Despite the higher sea-level rise projections in the latest IPCC report and improved ability of models to reproduce historical rates of sea-level rise, some respected scientists maintain still that even the new AR5 numbers are too low.Their argument primarily boils down to two different approaches: process models, which use climate models and physics to estimate sea-level rise, and semi-empirical models, which include evidence of past sea-level rise (mostly during the last ice age) to help determine the relationship between temperatures and sea level. Process models tend to produce lower estimates, empirical models higher ones.The recently released IPCC Working Group I report discounts empirical models, saying that “Many semi-empirical model projections of global mean sea-level rise are higher than process-based model projections (up to about twice as large), but there is no consensus in the scientific community about their reliability and there is thus low confidence in their projections.” Researchers like Potsdam University Professor Stefan Rahmstorf, who have worked with semi-empirical models, argue that a wholesale discounting of these approaches is erroneous, and represents an overly conservative approach from the IPCC.For now at least, it is still unclear just what exactly future sea-level rise will be, as uncertainty ranges remain large. At the same time, it is clear that the best estimates of future sea-level rise are considerably higher now than they were just five years ago. The level of sea-level rise by 2100 will mostly depend on which future emissions scenario societies follow, and it’s clear that significant efforts to reduce future emissions, coupled with well thought-out adaptation efforts, can significantly reduce future sea-level rise and its damaging impacts.
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I'm a professor at U Michigan and lead a course on climate change problem solving. These articles often come from and contribute to the course.

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