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More Weather Weirding — Godzilla El Nino vs a Mean Polar Amplification

We may have never seen heat like this before in the Equatorial Pacific. And as for atmospheric temperatures, 2015 is already locking in to shatter all-time global records set just last year. But despite a Monster El Nino raging across the world’s mid-section, despite a strengthening Jet Stream and a roaring storm track, the greatest warm atmospheric temperature anomalies are still centering in on the Arctic.

In other words, it appears that human-forced warming has taken so much cold out of the poles that there isn’t much of it left for the strengthening circumpolar winds to lock in.

A Godzilla El Nino

Equatorial Red Scar

(The angry red scar of anomalous ocean heat that is the tell-tale of a monster El Nino is plainly visible in today’s Climate Reanalyzer Sea Surface Temperature Anomaly [SSTA] graphic.)

All you have to do is look at the great red scar spanning more than half of the Equatorial Pacific Ocean on the upper Climate Reanalyzer map to tell it’s a Monster El Nino year. A zone that in this measure is now showing an amazing +1.26 C sea surface temperature anomaly above the already hotter than normal 1979-to-2000 average. A region where weekly average sea surface temperatures in NOAA’s El Nino monitor are now tied with the record 1997 event. There, according to NOAA, temperatures last week hit 2.8 degrees Celsius above average along an Equatorial band stretching from 120 to 180 West Longitude. As a result, the Equatorial atmosphere continued to heat up, continued to contribute to global temperatures that for 2015 will be the hottest ever recorded over the past 135 years.

Considering such a massive amount of heat boiling up off this key Equatorial zone, we’d tend to think that this region would also show atmospheric temperatures that are much warmer than average. And it does. But strangely, perhaps ominously, the highest average atmospheric temperature departures do not reside over these record hot waters. They instead show up where we might least expect them during a record El Nino year — at or near the poles.

Odd Polar Amplification

Atmospheric temperature anomalies

(El Nino is already contributing to stronger circumpolar wind fields, so why are the Antarctic and Arctic regions still so warm? Image source: Climate Reanalyzer.)

For both within the Arctic and Antarctic — it’s still much warmer than normal. In the Antarctic, a zone from 70 to 90 South features air temperatures that are between 10 and 20 degrees Celsius hotter than average. In the northern polar zone an even warmer region ranging from 14 to 20+ degrees Celsius above average stretches over the fractured and greatly thinned sea ice along an arc just north of Svalbard and on into Russian Siberia. Overall, the Arctic as a whole shows an extraordinary +1.27 C positive anomaly. The Antarctic is at +0.90 C. And the tropics, which includes our massive El Nino still lags at an admittedly impressive +0.64 C above the already hotter than normal 1979 to 2000 average.

Why is this temperature anomaly pattern so darn weird? It all has to do with atmospheric physics. During times of strong El Ninos, the temperature difference between the poles and the Equator tends to increase as the Equator warms. This, in turn, strengthens the Jet Stream. A strong Jet Stream, for its part, tends to keep cold air locked away at the poles. So, ironically, as the Equator warms with El Nino, the poles have a tendency to cool off a bit.

So far, for the Fall of 2015, this isn’t really what we’ve seen. Sure, the Equator has warmed up quite a bit. Concordantly, the Jet Stream appears to have strengthened somewhat. We still have a big ridge that tends to keep forming over the ridiculously and persistently warm Northeastern Pacific, but it’s not stretching all the way into the Arctic like it did last year. Meanwhile, Jet Stream velocities and related storm track intensities are hitting rather high values. Arctic Oscillation has also recently hit extremely high positive values. A strongly positive Arctic Oscillation traditionally tends to result in cold air remaining locked away in the Arctic, but considering the temperature anomaly maps, Arctic cold hasn’t really been all that cold of late.

image

(North America — surrounded on all sides by ridiculously hot water. How will the influences of this off the charts ocean warming impact North American and North Atlantic weather systems this Winter? Image source: Earth Nullschool.)

Is Human Forced Warming Meddling with the El Nino-Polar Interplay?

So why are the poles still tending to remain very warm even as the Equator warms? The first answer is that high greenhouse gas concentrations from human fossil fuel emissions tend to preferentially warm these regions. This is due to the fact that greenhouse gasses have their greatest warming impact during times of darkness or when the sun is at a low angle. Compounding this impact for the Arctic is the fact that a high overburden of both CO2 and methane hangs over the region — possibly due to heightening emissions from thawing permafrost, increasing forest fires, and increasing ocean-to-atmosphere carbon fluxes.

A second answer is that the overall atmospheric impacts of the current Monster El Nino may not have come into full swing yet. We do still have a very warm pool of water in the Northeastern Pacific and this warm pool has tended to somewhat resist the polar wind field intensifying effects of a strong El Nino. This warm pool has also given the current El Nino a springboard upon which to further intensify. So the push and pull between these two hot water zones may not be over yet.

All in all, this pattern points to more and more weather weirding on tap for this Winter. Jet Streams and storm tracks may run further to the north as a result — especially in the areas of the Pacific Northwest and in Northern Europe. Troughs may also tend to dig a bit deeper along the Central and Eastern US and on out into the North Atlantic. This is not exactly the forecast we would expect with such a strongly positive Arctic Oscillation. But the related cool air pool has retreated so far north as to, at least for now, not fully result in a strong El Nino + strong Arctic Oscillation related weather pattern. Instead, for now, what we are seeing is a weird kind of hybrid weather pattern that appears to be incorporating the influences of a Monster El Nino, of ongoing polar amplification, of the cool pool in the North Atlantic, of the abnormally warm Barents Sea, and of the Hot Blob still firmly entrenched in the Northeastern Pacific.

Links:

NOAA’s Weekly El Nino Report

NOAA’s Arctic Oscillation Index

Weather Underground El Nino Reports

Climate Reanalyzer

Earth Nullschool

Hat Tip to Ryan in New England

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The Storms of Arctic Warming: Polar Amplification, Vortex Disruption to Set off Extreme Weather Events For US, UK Yet Again

It’s happening again.

A story that starts in the Arctic where abnormally warm temperatures for this time of year are in the process of disrupting the polar vortex, shoving its node out of the Arctic Ocean and pushing it all the way south over Hudson and Baffin Bay. The result is a core of extreme cold shoved much closer to related warmer, southerly regions. A highly unstable event that is likely to spawn extreme weather for the US and UK yet again.

This polar heat amplification and related extreme weather is a signature of human-caused global warming. And though it wears a grotesque mask of what some would call a normal Arctic oscillation, it is anything but.

Our rapid production of greenhouse gasses since 1880 has caused the Arctic to warm, on average, by about 5.3 F (3.0 C). This rapid increase in warming is nearly 4 times that of the global average and resulted in temperatures for the Arctic, during the 20th Century, reaching a range not seen in at least 44,000 years and likely 120,000 years. Since warming has continued well into the first and second decades of the 21rst Century, Arctic temperature excursions are likely outside even that extreme range and may well now be approaching averages when parts of today’s Arctic first began to freeze and glaciate.

NASA Arctic Heat Amplification

(Arctic temperature increase from 1880 to 2012. Image source: Tamino. Data source: NASA GISS.)

The causes of this rapid Arctic amplification are manifold. First, human greenhouse gas emissions added more heat to the oceans and atmosphere. The polar sea ice, sitting atop a warming ocean went though a period of recession from the 1920s through the 1950s, hovered in about the same zone during the 60s and 70s and then commenced a more rapid melt phase from the 1980s onward.

Loss of Sea Ice and a Changing Jet Stream

Loss of sea ice reduced northern polar albedo (reflectivity) by a total of 4% since 1980 which increased Arctic heat capture by an amazing 6.4 watts per meter squared (more than 4 times that of human CO2 forcing over the entire globe). As a result, the seas under the Arctic ice cap began to even more rapidly warm. By 2012 the warming was intense enough to have reduced end-summer sea ice volume by 80 percent since 1979. Now, during winter time, a perforated and much diminished sheet of sea ice bleeds ocean heat into the Arctic atmosphere. As a result, cold air tends to be shoved out of the Arctic Ocean basin more and more often.

piomas-trnd2

(Sea ice volume losses with exponential trend. Image source: Wipneus. Data Source: PIOMAS.)

This bleeding of oceanic heat has bent the Jet Stream ever northward over two zones — one over Svalbard and one over Alaska. And both these Jet Stream weaknesses allow warmer air to rush into the Arctic from the south. These various heat forcings cause the winter time polar vortex to wobble uneasily over a warming Arctic Ocean even as it is more frequently ripped apart by warm air incursions through the oceanic weak points. Meanwhile, these vortex disruption and collapse events spill cold air southward over the continents and into the Atlantic Ocean.

Yet one more Polar Vortex Disruption

And for this winter, such Arctic heat driven polar vortex disruption and collapse events have been the norm. This week is featuring yet one more — sparking extreme weather that will revisit both the US and UK over the coming days.

T2_anom_satellite1

(Climate Change Institute Map Showing Arctic Heat Anomaly 2.68 C above the, already warmer than normal, 1979 to 2000 average. Image source: Climate Reanalyzer.)

Today, the Arctic temperature anomaly was 2.68 degrees Celsius above the, already warmer than normal, 1979 to 2000 average. Areas near Svalbard, Alaska, and Baffin Bay showed extraordinary temperature departures in the range of 15 to 20 degrees Celsius above average. Meanwhile a zone of cold, Arctic air has been shoved southward over the US, setting up extreme temperature differentials over a relatively small area and putting in place conditions ripe for extreme weather.

A Tale of Three Storms

A large Pacific storm now in the process of leaping over the west coast blocking pattern is forecast to dump up to 5 inches of rain on a parched California before injecting itself into the highly unstable atmosphere over the central and eastern US. Areas in the center of the US such as Oklahoma may experience a range of weather from thunderstorms to tornadoes and precipitation running the gambit between snow, hail, ice, and rain. This system is predicted to spread out, covering a massive swath from Texas to Maine and incorporating at least two low pressure systems. It will draw in a deep flow of warmth and moisture from the Gulf of Mexico and this warm and moisture laden air will abruptly collide with the much colder Arctic air to the north. Extreme rain, ice and snowfall are certainly possible as this intense event is expected to last from Saturday through Monday.

Across the Atlantic, as the Jet Stream invades southward and picks up speed, a gale formed to the south of Greenland and Iceland before barreling on into the storm ravaged shores of England and France. The gales and storms this winter for the region have been relentless, resulting in the stormiest winter ever on record for England and creating conditions so battering and exhausting that more than 21,000 sea birds are thought to have tragically lost their lives in at sea before washing up on French shores.

Now a strong double barrel low pressure system is bringing gale force winds and heavy rains back to a United Kingdom that has suffered an almost constant assault of storms since the middle of December. Flood warnings have again been issued for multiple counties and regions just north of London, which experienced 60 degree temperatures earlier this week, are expected to see snow. The storm is expected to sweep through the UK on Friday and Saturday before exiting Sunday. A storm of similar intensity is then expected to return to the UK on Monday where the process of gales and floods are likely to again repeat.

Sediment outflow England France Storms

(Sediment outflow from the swollen rivers of England and France on January 26 as yet another storm encroaches. Image source: Lance-Modis.)

In total, this worst continuous period of storms in UK history, has resulted in over a billion dollars in damages. Meanwhile, the storms are expected to continue through at least early March.

Overall, these extraordinary conditions cannot be entirely separated from the still-high temperature deviations occurring in the Arctic. Usually, by this time of year, the ice is solid enough and the warm air incursions are weak enough to allow at least some minor re-establishment of the polar vortex. Not so for 2014. The above average temperatures throughout the Arctic continue and show little sign of abatement as we head into March and the end of sea ice freeze season.

Links:

NOAA’s Ocean Prediction Center

Winter Storm Encroaches

NASA Lance-Modis

PIOMAS

The Climate Change Institute

NASA GISS

Arctic Hotter Than at Any Time in at Least 44,000 Years

Polar Albedo Loss Due to Ice Melt Twice that Predicted by Models

Hat Tip to Colorado Bob

Tamino

Wipneus

21,000 Sea Birds Lost Due to Extreme North Atlantic Storms

Blocking Pattern Serves up Nor’Easter One Week After Sandy as More and More Scientists Affirm Climate Change Made Superstorm Worse

 

A Nor’Easter that could  trouble the New Jersey, New York, Connecticut, Rhode Island and Massachusetts coasts with 50 mph wind gusts is in the process of forming today. A deep trough produced by a powerful blocking pattern and worsened by eroding Arctic Sea Ice is channeling a low pressure system that is likely to deepen off Cape Hatteras later tonight.

Models show the potential for a 990 mb low pressure forming off the Northeast coast come Wednesday. The result is that tropical storm force winds may bring 7-8 foot water rises (2-3 foot storm surges on top of high tides) to areas already devastated by Hurricane Sandy. Normally, a water rise of this level would result in light to moderate tidal flooding. However, in areas where dunes have been wiped out, sea walls and board walks beaten to bits, this rather moderate storm surge may re-flood some communities still reeling from last week’s disaster.

Tropical storm force winds may again knock out power in some areas still struggling to repair damage from Sandy. 1.3 million homes and businesses remain without power following the storm, down from 8.5 million a week ago. In addition, 1-2 inches of rain along the coast and snowfall in a region from Pennsylvania to Maine may cause further difficulty — especially for those still without power.

Though this storm is likely to be nothing like Sandy, it is a reminder of a new and ominous weather pattern taking shape this winter. According to numerous Arctic researchers, this year’s record sea ice melt is contributing to a powerful negative Arctic Oscillation. This weather condition has produced a strong trough swooping down from the Arctic and through the Eastern United States. The trough is producing numerous storms — one which combined with Hurricane Sandy to form a powerful superstorm. This week, the trough is bringing an early-season Nor’Easter. An odd second-week appearance of a storm that usually forms during winter.

These weather events may well be harbingers for very stormy conditions throughout the winter of 2012 for the US East Coast and Northeast. Jennifer Francis, an Arctic researcher at Rutgers University warned only just a few weeks ago that human climate change and sea ice loss was resulting in a situation that would likely produce a succession of powerful storms this fall and winter.

As the new storm forms off the East Coast, more scientists are affirming climate change’s role in both making Sandy worse and in producing a general climate of increasingly extreme weather. An article written by Dr. Jeff Masters, Dr. Bob Corell, and Dr. Kevin Trenberth entitled Did climate change contribute to Sandy? Yes published in Politico and Reuters yesterday. The article clearly stated that climate change made Sandy worse and warned that unless human carbon emissions are dramatically reduced more and more severe weather is to follow.

Climate scientists broadly agree that the extreme weather we’ve seen over the past few years is exactly what we’d expect to see in a changing climate. And it’s not just Sandy; we’re on track to have the hottest year in more than a century of record-keeping in the continental United States, the country has suffered one of the most crippling droughts in history, as well as one of the worst wildfire years in history. Last year, when Hurricane Irene hit the United States, meteorologists called it “unprecedented,” yet Sandy has already outpaced the damage from Irene.

We’ll probably never know the exact point when the weather stopped being entirely natural. But we should consider Sandy—and other recent extreme weather events – an early taste of a climate-changed world, and a grim preview of the even worse to come, particularly if we continue to pump more carbon pollution from smokestacks and tailpipes up into the atmosphere.

Jeff Masters is a meteorologist and former Hurricane Hunter, he now directs the climate blog WeatherUnderground. Bob Corell is an American climate scientist. Kevin Trenberth is the head of the US National Center for Atmospheric Research. Together, they represent over 150 years of climate science and meteorological experience.

Links:

http://www.politico.com/news/stories/1112/83335.html

http://www.wunderground.com/blog/JeffMasters/show.html

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