'Hurricane Sandy: The next climate wake-up call?'

[tacoman25]

I agree with the article. What is your problem with it?

I know of no one so ignorant to claim AGW THE cause of weather events/disasters. It plays a part in creating the weather, how can anyone deny that when global warming changes the very parameters which do create the weather?

Let's start with this:

- Clarity, however, is not beyond reach. Hurricane Sandy demands it: At least 40 U.S. deaths. Economic losses expected to climb as high as $50 billion. Eight million homes without power. Hundreds of thousands of people evacuated. More than 15,000 flights grounded. Factories, stores, and hospitals shut. Lower Manhattan dark, silent, and underwater.

So the premise from the get-go is: we need an explanation for this. It was a huge disaster, and now we need to point the finger somewhere...we need a whipping boy.

Then we get these vague statements from scientists as reasons we should place the blame for Sandy on AGW:

-“Would this kind of storm happen without climate change? Yes. Fueled by many factors. Is storm stronger because of climate change? Yes.”

“We can’t say that steroids caused any one home run by Barry Bonds, but steroids sure helped him hit more and hit them farther. Now we have weather on steroids.”

“Climate change amps up other basic factors that contribute to big storms. For example, the oceans have warmed, providing more energy for storms. And the Earth’s atmosphere has warmed, so it retains more moisture, which is drawn into storms and is then dumped on us.

So "weather on steroids" makes bad storms worse. Sounds easy enough. Sandy was a tropical system (until the very end). So we should be seeing more and stronger tropical storms with AGW, right? I mean, that's the natural connection one would have to make don't you think? This should be evident in longterm trends as AGW has increased...

And then we have this gem:

- Sandy featured a scary extra twist implicating climate change. An Atlantic hurricane moving up the East Coast crashed into cold air dipping south from Canada. The collision supercharged the storm’s energy level and extended its geographical reach. Pushing that cold air south was an atmospheric pattern, known as a blocking high, above the Arctic Ocean. Climate scientists Charles Greene and Bruce Monger of Cornell University, writing earlier this year in Oceanography, provided evidence that Arctic icemelts linked to global warming contribute to the very atmospheric pattern that sent the frigid burst down across Canada and the eastern U.S.

So let me get this straight - the fact that there was a strong Canadian cold front that collided with Sandy also implicates climate change because of a POSSIBLE link between less Arctic ice and a -AO pattern. That's interesting and maybe even possible (though hardly provable), but shouldn't the cold air coming south this early also have been warmer because of Arctic warming, and therefore not created as much of a stormy collision?

But it gets better...later in the article:

- Two months later, in the wake of Sandy, submerged families in New Jersey and New York urgently needed some help dealing with that rising-ocean stuff. (This is a political remark referring to Romney's quote about Obama pledging to 'slow the rise of the oceans' in 2008).

Ah so now, without any evidence whatsoever, we are blaming the flooding in New Jersey and New York on sea level rise. Let's not even bother getting some vague scientific quotes about that, let's just assume it played a major role in people being underwater from this storm.

And then the remainder of the article just goes into a political statement, leaving science completely behind.

[tacoman25]

Let play!

1. I'll give you that one. AGW was a factor though, even if not a major one.

2. Global SSTs are about 0.33C warmer than a century ago. The AMO had nothing/little to do with it. The likelihood of Atlantic Coast SSTs being higher has increased. I'm sure the SSTs were warm enough to sustain fast moving tropical systems over the northeast water during the past storms. Could even have been as warm as today, I don't know. Hurricane Carrol was one of the first weather events which sparked my interest way back when, the huge elm tree that fell on the front porch did the trick. Carrol was a cat3 storm right into New England I believe. The water must have been plenty warm.

Well, as to lesser lapse rates, in Sandy's case the storm was moving into and mixing with cool air invading the circulation. Lapse rates were steep, except of course in the core which retained it's column of deep warm convection till landfall.

3. Right, all the weather is affected by chaos, not just the bad. Nonetheless, Sandy would not have existed as the same entity. Maybe something else similar would have happened last year, today or tomorrow. So, technically, Sandy was made possible by the exact state of the global weather pattern it formed and moved through which happened only because of the exact state that preceded it etc. etc.

Seriously, how do we impart the AGW message without emphasizing the risks?

1. Glad we agree on that.

2. The AMO has nothing to do with rising global SSTs, you are right, but it has a lot to do with fluctuations on a regional basis, especially along the Atlantic Coast. As you say, while Sandy was a unique storm in how it mixed warm/cool air as it came ashore, there have certainly been other strong, warm-core/tropical storms that have impacted the area in the past, especially in the +AMO phase. The evidence that the AMO plays a significant role in tropical storms in the Atlantic is stronger than any correlation with AGW.

3. Yes, but there is no way to say exactly how Sandy would have developed differently without climate change. It could have been worse...who knows.

As far as imparting the AGW risks, just be realistic and acknowledge that we still have a lot to learn about how a warming world may effect our weather. It may not be a satisfactory answer, but it is the correct one.

[skierinvermont]

I really hate the whole counter-factual/hypothetical argument about what would happen in a particular instance w/ and w/o AGW. The butterfly effect makes the whole thing silly. The weather would have been totally different; could have been sunny, or snowing, or sprinkling. You can't even ask, what would happen with a similar atmospheric pattern, because AGW effects the entire atmospheric pattern.

I think it is best to just stick to what are the change in the odds of something similar happening? Have they gone up or down? I'm not convinced the odds of a Sandy-like storm have gone up. If I had to guess, I'd say they've gone up very slightly. Like from a 1 in 100 to a 1 in 95 year event. But that's guessing.. we don't have enough of a sample size of observations to prove it. I'm just basing that on the modeled small increase in TC intensity (2-11% this per double CO2). I could see AGW having already changed the probability of a Sandy-like event anywhere from +/-30% .. but if I had to guess I'd say +5%. Of course it all would depend on how you defined "Sand-like" as well.

[TerryM]

Yes, the most we can really say with an educated guess at this point is that SLR probably made the impact a little bit worse. And 10% might be a reasonable guess, we don't really know. But what we do know is that even if there had been zero SLR over the past 100 years, Sandy still would have been a major disaster for NYC with and the overall impact would not have been much less.

So to blame AGW for Sandy being a major disaster is just silly. Which has been my point all along.

Has anyone actually found a chart showing longterm NYC sea level rise? From what I've seen so far, there is not much correlation between SLR and the number/severity of damaging NYC storm surges.

Not only have we found it, we posted it back up the thread.

http://tidesandcurre...l?stnid=8518750

Interjecting the 4" figure - which apparently was pulled from someones nether regions, has skewed that portion of the argument. The correct, measured increase at the Battery is in excess of 15.5" since the beginning of the industrial age.

To argue that this made a negligible difference in damage caused by the storm is laughable.

Terry

[skierinvermont]

Not only have we found it, we posted it back up the thread.

http://tidesandcurre...l?stnid=8518750

Interjecting the 4" figure - which apparently was pulled from someones nether regions, has skewed that portion of the argument. The correct, measured increase at the Battery is in excess of 15.5" since the beginning of the industrial age.

To argue that this made a negligible difference in damage caused by the storm is laughable.

Terry

Are you sure the 15.5" is adjusted for changes in the height of land?

I find it hard to believe that SLR at NYC has been twice the global average. Also about 1/3-1/2 of the SLR is probably natural due to natural warming from the emergence from the LIA. Using the global figure of 8", then 4" is anthropogenic. If SLR at NYC is 15.5" then, 8-10" would be anthro. Although if SLR in NYC has outpaced the global average, the component of natural contribution may be larger than 1/3-1/2.

The reason for that such a large % of the SLR to date is natural is the lag between warming and SLR. However, that also means that we are committed to much more SLR even if warming stops today. And given we're already committed to another .5C+ of warming, that commits us to even more SLR. We're probably already committed to another 2-4 (possibly more) feet of SLR at present CO2 levels. And we are very quickly approaching CO2 levels that will commit us to near-complete melting of the Greenland ice sheet, which will commit us to 20+ feet of SLR.

[tacoman25]

Not only have we found it, we posted it back up the thread.

http://tidesandcurre...l?stnid=8518750

Interjecting the 4" figure - which apparently was pulled from someones nether regions, has skewed that portion of the argument. The correct, measured increase at the Battery is in excess of 15.5" since the beginning of the industrial age.

To argue that this made a negligible difference in damage caused by the storm is laughable.

Terry

Thank you, I missed that link before.

However, it appears the rise from 1850 to present has been fairly steady. AGW had virtually no effect from 1850-1900 as CO2 levels only barely increased over that period. From that graph, it looks like about 1/5 of the rise occurred by 1900. And it's interesting that sea levels were rising before there was much if any AGW effect, and there hasn't been much acceleration over the period that CO2 has rapidly increased in the atmosphere. We know that sea levels have gone up and down with CO2 in the past, so overall, it definitely seems doubtful that we could attribute all of the rise since 1900 to AGW.

Something in the 8-10" range is probably fair.

[skierinvermont]

Thank you, I missed that link before.

However, it appears the rise from 1850 to present has been fairly steady. AGW had virtually no effect from 1850-1900 as CO2 levels only barely increased over that period. From that graph, it looks like about 1/5 of the rise occurred by 1900. And it's interesting that sea levels were rising before there was much if any AGW effect, and there hasn't been much acceleration over the period that CO2 has rapidly increased in the atmosphere. We know that sea levels have gone up and down with CO2 in the past, so overall, it definitely seems doubtful that we could attribute all of the rise since 1900 to AGW.

Something in the 8-10" range is probably fair.

See my other post.. I could see the anthro component at NYC as low as 5".. or as high as 12"

It depends on

1. Is the tide guage record adjusted for changes in land elevation or is this just raw data?

2. 1/4-1/2 of the global SLR is probably natural.

3. And an even higher % of SLR at NYC may be natural due to natural oscillations outpacing the global effect.

[tacoman25]

Are you sure the 15.5" is adjusted for changes in the height of land?

I find it hard to believe that SLR at NYC has been twice the global average. Also about 1/3-1/2 of the SLR is probably natural due to natural warming from the emergence from the LIA. Using the global figure of 8", then 4" is anthropogenic. If SLR at NYC is 15.5" then, 8-10" would be anthro. Although if SLR in NYC has outpaced the global average, the component of natural contribution may be larger than 1/3-1/2.

The reason for that such a large % of the SLR to date is natural is the lag between warming and SLR. However, that also means that we are committed to much more SLR even if warming stops today. And given we're already committed to another .5C+ of warming, that commits us to even more SLR. We're probably already committed to another 2-4 (possibly more) feet of SLR at present CO2 levels. And we are very quickly approaching CO2 levels that will commit us to near-complete melting of the Greenland ice sheet, which will commit us to 20+ feet of SLR.

I didn't even read your post yet, but I see we came to the same guesstimate. Great minds think alike.

However, how much of a lag is there? If we have already seen 100+ years of AGW with only a slight increase in SLR rates, what makes you believe we will see 2-4 feet of rise from the next .5C of warming? That seems like a drastic increase from the current warming to SLR ratio.

[skierinvermont]

I didn't even read your post yet, but I see we came to the same guesstimate. Great minds think alike.

However, how much of a lag is there? If we have already seen 100+ years of AGW with only a slight increase in SLR rates, what makes you believe we will see 2-4 feet of rise from the next .5C of warming? That seems like a drastic increase from the current warming to SLR ratio.

2-4' might have been a bit high for .5C.. maybe 1-3' is a better estimate (and leaning towards the lower side of that). 4-8" of that 1-3' is probably already committed to at current temperatures (3mm/yr for another 50 years before stabilization = 6"). Another .5C though should really start to melt the Greenland ice sheet. Like you, I'm a little hesitant to predict rapid acceleration that really hasn't started yet. But on the other hand, we can be pretty confident that Greenland will really start to melt soon as we near temperatures that have melted it historically. And I believe we are just starting to see the beginnings of that on Greenland (the 500GT/yr mass loss, large melt ponds, calving ancient ice shelves).

.5C is just the beginning. There is likely a very sharp cuttoff between .5C and 2C more warming where on one side Greenland doesn't melt except a bit on the edges, and above that it melts entirely. The local albedo effect make it a very unstable situation. As you know, I think the albedo effect is overplayed a bit by some on a global scale (it's still significant), but locally the effect can be huge. .5C might commit us to 1-3' of SLR, while 1.5C would commit us to 15'.

[TerryM]

Thank you, I missed that link before.

However, it appears the rise from 1850 to present has been fairly steady. AGW had virtually no effect from 1850-1900 as CO2 levels only barely increased over that period. From that graph, it looks like about 1/5 of the rise occurred by 1900. And it's interesting that sea levels were rising before there was much if any AGW effect, and there hasn't been much acceleration over the period that CO2 has rapidly increased in the atmosphere. We know that sea levels have gone up and down with CO2 in the past, so overall, it definitely seems doubtful that we could attribute all of the rise since 1900 to AGW.

Something in the 8-10" range is probably fair.

Since the use a linear function moving back or forth between years is easy - the rise shown from per century is given as .91' or 10.92", to take us back to 1900 we'd get 12.23" - or very close to Skiers high estimate.

The problem using this method is that it's easy to see that we're at present much higher than the linear. My guess - and it's nothing more than a guess at this point is that 16" would give us a ballpark figure. Further the industrial age and it's contribution to CO2 is usually started from about 1870, so another 30 years of SLR should be included. That 30 year period, using the Battery data would add 3.28" to the above figures.

I'm sure someone has flattened the seasonal ups and downs without resorting to a simple linear flattening of the graph, and that this produces a much more accurate picture of what is most certainly an ever tightening upward curve. For the moment acceptance of either the 12,23" or the 15.51" figures should be close enough to work with.

Something that I feel might be even more productive would be a look at the history of Greenland blocking, particularly in late fall. If the strength, size or frequency is linked to ice loss, post 2000 Arctic wind patterns, SST's or other variabilities that are known to be products of AGW, the risks looking forward should be clear.

Terry

[tacoman25]

Since the use a linear function moving back or forth between years is easy - the rise shown from per century is given as .91' or 10.92", to take us back to 1900 we'd get 12.23" - or very close to Skiers high estimate.

The problem using this method is that it's easy to see that we're at present much higher than the linear. My guess - and it's nothing more than a guess at this point is that 16" would give us a ballpark figure. Further the industrial age and it's contribution to CO2 is usually started from about 1870, so another 30 years of SLR should be included. That 30 year period, using the Battery data would add 3.28" to the above figures.

I'm sure someone has flattened the seasonal ups and downs without resorting to a simple linear flattening of the graph, and that this produces a much more accurate picture of what is most certainly an ever tightening upward curve. For the moment acceptance of either the 12,23" or the 15.51" figures should be close enough to work with.

Something that I feel might be even more productive would be a look at the history of Greenland blocking, particularly in late fall. If the strength, size or frequency is linked to ice loss, post 2000 Arctic wind patterns, SST's or other variabilities that are known to be products of AGW, the risks looking forward should be clear.

Terry

Well, if you see skiier's post above, there are other variables for NYC that have to be taken into account. It seems pretty unlikely that AGW is responsible for 15" of SLR at NYC at this point. Not only is that way more than the global average, but it's also more than most places along eastern seaboard. And again, you have to account for the local factors and natural recovery of sea levels from the LIA.

[TerryM]

Taco

Not trying to be snarky but were there sea level drops in the LIA? I don't know the answer so I'm not trying to start an argument. The data should be out there somewhere and it would be interesting to find out. My understanding was that the LIA was fairly localized & therefore wouldn't have an effect, but I've been wrong many times.

Terry

[skierinvermont]

Taco

Not trying to be snarky but were there sea level drops in the LIA? I don't know the answer so I'm not trying to start an argument. The data should be out there somewhere and it would be interesting to find out. My understanding was that the LIA was fairly localized & therefore wouldn't have an effect, but I've been wrong many times.

Terry

Yes there was quite a dip, and sea levels in the medieval warm period were fairly close to what they are today. Given the earth is much warmer today than the MWP, but sea levels were similar, that further supports my conclusion that 1/3-1/2 of global SLR has been a natural recovery from the LIA.

[TerryM]

Yes there was quite a dip, and sea levels in the medieval warm period were fairly close to what they are today. Given the earth is much warmer today than the MWP, but sea levels were similar, that further supports my conclusion that 1/3-1/2 of global SLR has been a natural recovery from the LIA.

There seems to be as much dispute about beginning and ending dates for the LIA as there is for the MWP. The graph above seems to indicate SLR from ~650 to ~1150, then a drop from then until~1750, then an upswing that passes the earlier levels in about 1950.

Is that the way you're reading it & does that correlate to dates you'd use to describe temperature swings over the last 2 millennia?

BTW I'm going to see if I can find a more detailed chart.

Terry

[TerryM]

Fig A-1 shows a very different scenario with little or no rise other than a minor uptick about a thousand years ago. Apologies for not knowing how to extract a graph from a PDF.

"During the last 3 000 years, the mean sea level has

been below values observed at present (Figure 1a).

Furthermore, variations occurred slowly. For example,

the change in sea level over the 1 000 years up to year

1800 was in the range of a few centimetres"

http://www.wcrp-clim...ge_web_EN-1.pdf

Terry

EDIT

• Stable sea level from 200 BC until 1000 AD
  
• A 400-year rise by about 6 cm per century up to 1400 AD
  
• Another stable period from 1400 AD up to the late 19th C
  
• A rapid rise by about 20 cm since.
  

http://www.realclimate.org/index.php/archives/2011/06/2000-years-of-sea-level/

This is an interesting topic, but probably needs a separate thread. To date I haven't been able to find another chart that shows the LIA as clearly as the one you posted.

[WeatherRusty]

Just a few random thoughts:

Average major hurricane wind speed increases due to warming seas are expected to be something near 5%.

Seal level rise has gone from 2mm per year increase to 3mm per year over the past several decades.

The east coast of North America is expected to experience sea level rise greater than the global average due to a loss of gravitational mass as the Greenland ice sheet melts.

[skierinvermont]

Fig A-1 shows a very different scenario with little or no rise other than a minor uptick about a thousand years ago. Apologies for not knowing how to extract a graph from a PDF.

"During the last 3 000 years, the mean sea level has

been below values observed at present (Figure 1a).

Furthermore, variations occurred slowly. For example,

the change in sea level over the 1 000 years up to year

1800 was in the range of a few centimetres"

http://www.wcrp-clim...ge_web_EN-1.pdf

Terry

EDIT

• Stable sea level from 200 BC until 1000 AD
  
• A 400-year rise by about 6 cm per century up to 1400 AD
  
• Another stable period from 1400 AD up to the late 19th C
  
• A rapid rise by about 20 cm since.
  

http://www.realclima...s-of-sea-level/

This is an interesting topic, but probably needs a separate thread. To date I haven't been able to find another chart that shows the LIA as clearly as the one you posted.

Your paper is probably better. I was actually going to come back later and post that my graph was not what I thought it was. I've been reading the paper it came from and if I understand correctly it is just modeling based on temperature. It might take some direct observation of sea level into account, but I'm not sure. But it's mostly modeling of sea level based on temperature. Your graph does show some declining sea levels after the MWP, but not nearly as much.

That slightly weakens the argument for natural sea level rise this century. But I still think a substantial portion is natural considering how much sea levels rose prior to 1950 when most of the warming was also natural.

One way of figuring it is that if 20-25% of the .8C of warming to date is natural (the sun and lack of volcanoes), current sea level rise has been 8", and we're committed to 6" more, then the total sea level rise is 14" and 20-25% of that is 3". Which means 3" of the 8" thus far has been natural.

So 3/8ths of sea level rise thus far is natural.

[TerryM]

Could well be - it's a subject I haven't involved myself in. The amount of isostatic rebound can be large. In northern Newfoundland I've walked across areas where Vikings moored their ships that are now 5' above high tide & in Labrador the beach lines are evident on every bluff.

My understanding is that the east coast of the US is more susceptible to sea level rise than most areas. Boston, NYC even Washington may be due for problems.

Terry

[Alpha5]

Could well be - it's a subject I haven't involved myself in. The amount of isostatic rebound can be large. In northern Newfoundland I've walked across areas where Vikings moored their ships that are now 5' above high tide & in Labrador the beach lines are evident on every bluff.

My understanding is that the east coast of the US is more susceptible to sea level rise than most areas. Boston, NYC even Washington may be due for problems.

Terry

Washington is on a river far removed from an ocean, I doubt they have issues, even in a worse case scenario

[TerryM]

Washington is on a river far removed from an ocean, I doubt they have issues, even in a worse case scenario

Apparently the gov. agrees with you.

From the final page of the report on storm surge in the DC area:

"However, in order to complete a regional hurricane evacuation

transportation study, the recommended tasks outlined in Table 3-1 would need to be completed.

NHP funding is limited and there is no guarantee that sufficient funds would be available to

continue the study with next fiscal year funds without leveraging funds from other federal

agencies and potential state contributions"

http://www.iwr.usace.army.mil/nhp/HES/WashingtonDCandNOVA/Current2009StormSurgeMapping/Report/DC&NOVA-StormSurgeMap-Main.pdf

Terry

[The_Global_Warmer]

the most updated SLR product is this one. the last year has seen a huge rise. Even with seasonal signals retained.

As of early to mid September it was running 18MM ahead of 2011 at this time and 19MM ahead of 2010 at this time. Regardless of time of year SLR levels have spiked up big time.

So even though it is a small detail Sandy came around during the highest SLR levels likely in modern history along the East Coast with such warm SST's. But this is nothing compared to what's coming.

You guys can do regression analysis all day to say the Sea Level rise has slowed and isn't going to be a catasrophe. But back of the envelope analysis on the top chart shows us at 44.55MM right now the peak season is not until the end of the year.

Vs 2002 we are 32-35MM above this time of year.

VS 2000 we are 45-47MM above this time of year.

For many reasons there was almost no cycle this year globally during the dip. But this can't be attributed to ENSO or Global SST's. We have seen a large rise for over 15 months. We are likely going to have seen upwards of 2 Trillion + Tonnes of land ice loss in 2011 and 2012 combined.

http://www.sciencedaily.com/releases/2012/11/121101153549.htm

"What's missing from the models used to forecast sea-level rise are critical feedbacks that speed everything up," says Hay. He will be presenting some of these feedbacks in a talk on Nov. 4, at the meeting of The Geological Society of America in Charlotte, North Carolina, USA.

One of those feedbacks involves Arctic sea ice, another the Greenland ice cap, and another soil moisture and groundwater mining.

"There is an Arctic sea ice connection," says Hay, despite the fact that melting sea ice -- which is already in the ocean -- does not itself raise sea level. Instead, it plays a role in the overall warming of the Arctic, which leads to ice losses in nearby Greenland and northern Canada. When sea ice melts, Hay explains, there is an oceanographic effect of releasing more fresh water from the Arctic, which is then replaced by inflows of brinier, warmer water from the south.

"So it's a big heat pump that brings heat to the Arctic," says Hay. "That's not in any of the models." That warmer water pushes the Arctic toward more ice-free waters, which absorb sunlight rather than reflect it back into space like sea ice does. The more open water there is, the more heat is trapped in the Arctic waters, and the warmer things can get.

Then there are those gigantic stores of ice in Greenland and Antarctica. During the last interglacial period, sea level rose 10 meters due to the melting of all that ice -- without any help from humans. New data suggests that the sea-level rise in the oceans took place over a few centuries, according to Hay.

"You can lose most of the Greenland ice cap in a few hundred years, not thousands, just under natural conditions," says Hay. "There's no telling how fast it can go with this spike of carbon dioxide we are adding to the atmosphere."

This possibility was brought home this last summer as Greenland underwent a stunning, record-setting melt. The ice streams, lubricated by water at their base, are speeding up.

Hay notes, "Ten years ago we didn't know much about water under the Antarctic ice cap." But it is there, and it allows the ice to move -- in some places even uphill due to the weight of the ice above it.

"It's being squeezed like toothpaste out of a tube," explains Hay. The one thing that's holding all that ice back from emptying into the sea is the grounded ice shelves acting like plugs on bottles at the ends of the coastal glaciers. "Nobody has any idea how fast that ice will flow into the oceans once the ice shelves are gone."

Another missing feedback is the groundwater being mined all over the world to mitigate droughts. That water is ultimately added to the oceans (a recent visualization of this effect in the U.S. was posted by NASA's Earth Observatory: http://earthobservatory.nasa.gov/IOTD/view.php?id=79228).

All of these are positive feedbacks speeding up the changes in climate and sea-level rise.

"You would expect negative feedbacks to creep in at some point," says Hay. "But in climate change, every feedback seems to go positive." The reason is that Earth's climate seems to have certain stable states. Between those states things are unstable and can change quickly. "Under human prodding, the system wants to go into a new climate state."

Further information: https://gsa.confex.com/gsa/2012AM/finalprogram/abstract_209198.htm

South West Greenland shouldn't have exposed ice on November 2nd with Fresh Water still pouring into the streams. Natural Variability might drive the NAO and stuff like that, but the ice albedo effect(dirty ice effect) is exaperating the situation big time. This is a scary situation considering the climate/North Atlantic is going to warm so much more. We could easily be looking at a powerful 6-7 month melting season for the southern 1/3rd of Greenland.

As far as the AMO is concerned. This speaks volumes. We can add 2012 as another year near the record setting numbers. Even if we some how manage a -AMO unless we actual change the baseline the AMO isn't going negative again. At best you will get a 1930s to 1950s period, at best. With the continued GHG increase by the time the AMO goes negative, we might not drop off much from now if at all. Without the expansive ice over and cold bank from it the arctic region is to vulnerable to climate shifts. We have seen zero evidence of this changing except for the worse.

Even with all of this evidence the majority on this board thinks One Meter of SLR by 2100 is a stretch.

and a few inches by 2050 isn't even likely.

[PhillipS]

Washington is on a river far removed from an ocean, I doubt they have issues, even in a worse case scenario

Washington is on the tidal estuary of the Potomac River and does have concerns with flooding and sea level rise. Here is a link to the 2008 Report on Flooding and Stormwater in Washington D.C.

I lived in the DC area for 26 years and flooding occured on several occasions. An area particularly vulnerable to flooding is the Old Town Alexandria waterfront just across the Potomac from Washington. Here is a picture of the flooding from Hurricane Sandy.

It can only get worse as sea level rise continues.

[TerryM]

NYC has been experiencing a sea level rise of 11"/century since 1856. We are certainly experiencing an increase over that trend over the last few decades & Friv has pointed out the very rapid global SLR within the last few years.

From 1900 to 2050 this would give us an increase of 16.5" - as long as things slow down from where they are heading and revert to the long time trend. Most of NYC's base infrastructure - subways, street levels etc, were in place by the beginning of the 20th century & probably weren't designed to cope with an additional 16" of sea level.

If we don't expect increased hurricane strength, don't expect SLR to increase and will accept the same risks that 19th century engineers built into their city plans - then all we have to do is build a 16" levee system from Massachusetts to Florida. ;-^

Terry

[TerryM]

With the addition of "Son of Sandy" are we now getting to the point that we can attribute some of the anomalies on the east coast to feedback from Arctic conditions?

Fisher has noted a wobbling of the Jet Stream that she links to loss of ice cover. Large low pressure systems that hug the ice edge have been contributing to big pressure deltas & very high winds to the east and west of Greenland. Perhaps rough measurements such as AO are not capturing what is happening in the far north & the more southerly reactions to these events is wreaking havoc in more populated climes.

When Sandy was in full bloom a huge low was moving NE out of Hudson Bay. As Son of Sandy was dropping snow in central park, a system just south of Greenland was disturbing a lot of fish.

We can certainly expect that Arctic weather is reacting to the loss of ice. If we're witnessing temperate zone weather that is in some way influenced by the Arctic regime isn't it reasonable to assume we'll see more of the same going forward.

Terry

[tacoman25]

With the addition of "Son of Sandy" are we now getting to the point that we can attribute some of the anomalies on the east coast to feedback from Arctic conditions?

Fisher has noted a wobbling of the Jet Stream that she links to loss of ice cover. Large low pressure systems that hug the ice edge have been contributing to big pressure deltas & very high winds to the east and west of Greenland. Perhaps rough measurements such as AO are not capturing what is happening in the far north & the more southerly reactions to these events is wreaking havoc in more populated climes.

When Sandy was in full bloom a huge low was moving NE out of Hudson Bay. As Son of Sandy was dropping snow in central park, a system just south of Greenland was disturbing a lot of fish.

We can certainly expect that Arctic weather is reacting to the loss of ice. If we're witnessing temperate zone weather that is in some way influenced by the Arctic regime isn't it reasonable to assume we'll see more of the same going forward.

Terry

Patterns tend to be persistent. While "Son of Sandy" was not a major storm from a historical perspective (aside from providing an unusually early snowfall to NYC and Jersey, it was just your typical Nor'easter), it provided more headlines mainly because it hit the same areas just hit by Sandy. But it is not unusual at all for one area to be hit in a short period of time by a succession of storms thanks to the dominant pattern (see my area in Dec 2006-07 with a series of crippling snowstorms).

But all that aside, the overall blocking pattern was actually quite different with these two storms. Sandy had major -NAO blocking, while the Nor'easter occurred with +NAO.

[ORH_wxman]

The two long wave patterns were very different producing each storm. About the only similarity was that both storms affected the northeast U.S.

[TerryM]

Patterns tend to be persistent. While "Son of Sandy" was not a major storm from a historical perspective (aside from providing an unusually early snowfall to NYC and Jersey, it was just your typical Nor'easter), it provided more headlines mainly because it hit the same areas just hit by Sandy. But it is not unusual at all for one area to be hit in a short period of time by a succession of storms thanks to the dominant pattern (see my area in Dec 2006-07 with a series of crippling snowstorms).

But all that aside, the overall blocking pattern was actually quite different with these two storms. Sandy had major -NAO blocking, while the Nor'easter occurred with +NAO.

Are you sure? I'm seeing strong -NAO for the period.

Terry

[ORH_wxman]

The NAO was technically still negative during the storm using the CPC version, but it was rapidly approaching positive territory. Sandy had a huge cutoff low to the east of it with a bent back mega-block into E Canada and over to near Greenland. This current storm has no such cutoff to the east and only has a weak split ridge in E Canada with a more robust block well to the east out over the central Atlantic.

[OSUmetstud]

The NAO was technically still negative during the storm using the CPC version, but it was rapidly approaching positive territory. Sandy had a huge cutoff low to the east of it with a bent back mega-block into E Canada and over to near Greenland. This current storm has no such cutoff to the east and only has a weak split ridge in E Canada with a more robust block well to the east out over the central Atlantic.

Sandy was a substantial part of the reason for the nor'easter. Hurricanes can affect the hemispheric pattern for like 30 days after recurvature. I think it may be partly responsible for breaking down the -NAO/-AO to positive levels over the next few days.

[skierinvermont]

I just came in here to guess that somebody would try to attribute the noreaster to AGW but looks like somebody already did.

Early season snowfalls will become much less common with AGW, not more.