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NASA: Monster El Nino + Climate Change Means ‘Not Normal’ Winter is On the Way

“Over North America, this winter will definitely not be normal. However, the climatic events of the past decade make ‘normal’ difficult to define.”  — Bill Patzert, climatologist at NASA’s JPL speaking in Earth Observatory today.

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It’s official, as of this Monday’s weekly NOAA ENSO report, a still growing 2015 El Nino had taken yet one more step into monster event territory. Hitting a +1.5 C sea surface temperature anomaly in the benchmark Nino 3.4 zone over the period of July through September even as weekly values rocketed to an amazing +2.4 C above average, the 2015 El Nino heightened yet again — making a substantial jump in overall ocean heat content. But according to a recent report out of NASA’s Earth Observatory, it appears we’re just beginning to see the full potential of this thing.

As Big or Bigger in Ocean Heat Content Than 1997-1998

For the 2015 El Nino, an event that NASA scientists are now calling ‘too big to fail,’ appears bound to continue strengthening through late Fall and Early Winter. Growing into a climate and weather wrenching oceanic and atmospheric heavyweight that will significantly impact North American weather patterns during the Winter of 2015-2016. This extreme climate event — which is currently building to an extraordinary ocean heat content anomaly in the Central and Eastern Pacific — is now comparable to the top three strongest El Ninos on record. In other words, and according to NASA: “El Niño is strengthening and it looks a lot like the strong event that occurred in 1997–98.”

Sea surface height anomalies

(Sea surface height anomaly graphic provided by NASA shows a pattern very similar to 1997. Positive ocean surface height anomalies, indicated in red above, are the hallmark of an El Nino that is currently ranked among the top three strongest events observed for October. Image source: NASA.)

Ocean surface heights, as seen in the Earth Observatory graphic above, now show a pattern very similar to the monster 1997-1998 El Nino.

In a typical El Nino, Kelvin Waves transfer Equatorial Pacific Ocean heat from west to east which in turn sets off a rise in sea surface heights by thermally expanding the water column throughout the traditional Nino zones. And during the Fall of 2015 what we’re seeing is a big thermal and related ocean surface bulge swelling seas throughout the Eastern and Central Equatorial Pacific. To this point, Earth Observatory notes: “October sea level height anomalies show that 2015 is as big or bigger in heat content than 1997.”

Strong Westerly Wind Burst Lends More Energy to El Nino

Supporting NASA’s conclusions that El Nino intensity during 2015-2016 may hit near or beyond the top of the chart is a recent intensification of westerly winds over the Western Equatorial Pacific. Throughout 2014 and growing into 2015, these westerly wind bursts have fed El Nino by pushing warmer, Western Pacific waters eastward — thus increasing ocean heat content in the El Nino zone to near record levels.

Over the past week, another very strong westerly wind burst was again supplying El Nino with a warm water recharge. By tomorrow, the Global Forecast System model shows not one but four cyclones driving a strong westerly wind pattern from the Philippines all the way to the Date Line:

image

(Yet one more strong westerly wind burst is providing the already powerful 2015 El Nino with another boost. Note the extensive reverse trade wind pattern stretching all the way to the Date Line. Image source: Earth Nullschool.)

It’s a pretty significant westerly wind pattern — near to par with some of the related weather events (MJO) earlier this year that were among the strongest in the meteorological record. These winds will rise to near gale-force gusts in some regions and provide a dominant fetch from west to east across a 1,500 mile section of Pacific Ocean. According to NASA:

“This [weakening of the trades] should strengthen this El Niño. All multi-model averages predict a peak in late fall/early winter. The forecaster consensus unanimously favors a strong El Niño…Overall, there is an approximately 95 percent chance that El Niño will continue through Northern Hemisphere winter 2015–16.”

Not Normal Winter Weather on the Way

A typical powerful El Nino of this kind would tend to drive a very intense train of moisture into the West Coast of the US, make for a cool and very wet winter across the southern US, and drive warmer temperatures and drier conditions across the northern tier. Climatologists, however, are uncertain how interactions between the current powerful El Nino and a globally changing weather pattern set off by a human-forced warming of the atmosphere to 1 C above 1880s levels (or about 1/4th the difference between the 20th Century and the last ice age, but on the side of hot) will interact.

Very warm sea surface temperatures, likely due to both a climate change-forced heating of ocean surface waters and a weakening of the Gulf Stream, off the Eastern Seaboard hint that storms along the US East Coast and particularly for the US Southeast may hit extreme intensity if an El Nino associated trough digs in. Meanwhile extraordinarily intense sea surface temperature anomalies in the range of +2 to near +6 C above average off the US West Coast associated with a ‘hot blob’ that has lingered in this region for many seasons has caused some to question whether California will see the high intensity rainfall events typical of powerful El Ninos during the latter half of the 20th Century.

image

(Extreme sea surface temperatures off the US West Coast can generate a kind of atmospheric inertia in which high pressure systems tend to develop — deflecting or weakening storms moving across the meridional Pacific northward toward Canada, Alaska and even the Polar region. Alternatively, an El Nino strong enough to over-ride this ocean and atmospheric block is likely to generate some very extreme storms — spurring events possibly exceeding those in the modern climate record. Image source: Earth Nullschool.)

For the US West Coast, the region may be balancing on a razor’s edge. If El Nino is strong enough to overwhelm the atmospheric and ocean inertia generated by the hot blob, storms running into that region could be extremely intense. On the other hand, if the hot blob holds or deflects the moisture stream northward, California may not see a drought-busting delivery of rainfall (See Godzilla El Nino vs the Hot Blob).

To this point, we’ll leave Earth Observatory with the next to last word:

“[The] elements of our changing climate are too new to say with certainty what the winter will bring.”

A pretty significant statement when one begins to fully take in its meaning — that climate change may be starting to set weather forecasting out of the context of the latter 20th Century. That it’s NASA’s view that aspects of modern weather prediction for El Nino events may have already been set off kilter by ‘elements of our changing climate.’

New Global Temperature Records For 2015 Likely a Lock

But what we do know is that the ocean-to-atmosphere heat back-up generated by what could be a record El Nino, when combined with the enormous added heat forcing provided by human fossil fuel emissions, will almost certainly set new global high temperature records for 2015 and possibly for 2016. This, unfortunately, means that we’ve already started on a dangerous path toward the far more disruptive +1.5 and +2 C above 1880s benchmarks. A range that many scientists associate with a greatly increased risk of hitting climate tipping points.

Links:

Earth Observatory: El Nino Strengthening

Monster El Nino Emerging From the Depths

NOAA’s Weekly El Nino Report

Earth Nullschool

Godzilla El Nino vs the Hot Blob

Dr. Lenton’s (somewhat conservative) Exploration of Climate Tipping Points

Climate Change’s Hot Blob Still Blankets Northeastern Pacific

Halfway to 2 C

Nasty Signs North Atlantic Overturning Circulation is Weakening

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Despite Unprecedented Heat Transfer to Oceans, NASA Shows January 2014 was 3rd Hottest On Record; Models Hint at El Nino, Big Atmospheric Temperature Jump on Horizon

A cycling between warm ocean surface waters and cool ocean surface waters in the Eastern Pacific called El Nino and La Nina, for centuries, has been a primary driver of relative atmospheric warmth and coolness. During the times when the Eastern Pacific disgorged its heat, the Earth’s atmosphere warmed. And during times when the same region cooled, a portion of atmospheric heat was taken back and transferred into the world’s oceans.

ENSO Index since 1950

(ENSO Index since 1950. Image source: ESRL/NOAA.)

Since about 1300 CE, this cycling governed the top and bottom ends of average global climate. Temperatures during this time remained within about .3 degrees Celsius of a very stable base line. But beginning around 1900, that cycle was broken, with unprecedented and rapidly increasing warmth proceeding along with an explosive human use of fossil fuels.

Since that time, and especially since the late 1970s, the regular El Nino and La Nina cycle has been a less and less reliable governor of atmospheric temperatures. Certainly the El Nino years were generally hotter — a majority of El Nino years since 1980 were record hot ones. And the La Nina years were definitely cooler. But the overall temperature curve skewed upward and even La Nina years featured within the range of top ten hottest years on record with increasing frequency.

The past five year trend only showed a more extreme amplification, when taken in the broader context of an ongoing ocean heat transfer.

The last El Nino year, 2010, was also the last hottest year on record. Being a relatively lack-luster El Nino, with only moderate warm temperature departures for the Eastern Pacific, it is abundantly clear that human-caused global warming was the underlying driver for this record breaker.

Global temperatures since 1880 NASA GISS

(Global Temperature variation since 1880. Image and data source: NASA GISS.)

In the years that followed, 2011 and 2012 featured La Ninas while 2013 was a year in which the Eastern Pacific is neither warm nor cool (ENSO neutral).

In a normal world, under normal climate conditions, such a long period of cool surface waters covering the Eastern Pacific would have driven global temperatures down below typical averages. The vast waters would have sucked heat out of the air and deposited it into the oceans. And, as we will see below, it did suck a massive amount of heat out. But not enough even to bring global temperatures back into the average range, much less put it below the average (both NASA and NOAA show 2011-2013 as top 10 hottest years on record). This is very concerning, especially when we consider, as we do below, that the rate of atmosphere to ocean heat exchange is currently unprecedented.

Despite four years of ongoing coolness in the Eastern Pacific and of a much more vigorous than usual mixing of ocean and atmosphere, global surface temperatures have remained at or near record highs during a time that should have featured a down-turn. Meanwhile, ocean heat content spiked.

And the start of 2014 is no exception.

Third Hottest January On Record

Come January 2014 with ENSO still remaining on the cool side of neutral, reports from NASA GISS show January 2014 was the third hottest in the climate record since measurements began in 1880. NASA’s Land-Ocean Temperature Index  reveals temperatures for the month at .70 degrees Celsius hotter than the 1950 to 1980 average and .90 degrees Celsius hotter than the annual average for 1880.

Global Surface Temperature Anomaly NASA GISS

(Global Surface Temperature Anomaly in degrees Celsius of departure from the, already warmer than normal, 1951-1980 average. Image source: NASA GISS.)

By contrast, January of 2002 and 2003, which were both El Nino years, tied for second hottest in the record at .72 degrees Celsius hotter than the average while 2007, also an El Nino year, showed January at .93 C hotter than average. So the temperatures we are seeing this year, a year in which the Eastern Pacific is still sucking up atmospheric heat, are nearly as warm as recent times in which that same vast stretch of ocean was bleeding heat back to the airs above it.

For atmospheric temperatures to be so hot without the presence of El Nino is, today, an ominous sign for many reasons. First, we are seeing amazing heat spikes in the Arctic. And these spikes largely drove the January temperature anomaly — a clear sign that northern polar amplification is becoming a powerful driver of continued atmospheric warming in its own right. One that may play a harmonic role with the ENSO cycle as the next few decades progress. Second, we may be beginning to see that the ocean, which has taken up so much excess atmospheric heat is starting to lag as a sink even as it is grudgingly shoved back toward dumping a portion of that extraordinary excess warmth into the atmosphere.

As mentioned above, we have seen an unprecedented transfer of heat into the surface, middle and deep ocean over the past decade. And the Argo float graph below bears a stark testimony to this transfer:

OHC_2an

(Image source: L Hamilton. Image data: NOAA. Produced for The Arctic Ice Blog. Note the extraordinarily steep slope indicating recent ocean warming.)

Note the huge jump in ocean heat content that began in 2001 just as the most recent negative PDO and La Nina cycle began to kick in. This vast heat content is now a latent source for atmospheric warming that will, as many scientists note, almost certainly come back to haunt us once the ocean heat uptake mechanism is exhausted.

This Unprecedented Heat Transfer

The graph above provides us with much cause for concern, as ocean heat is certainly spiking. But a recent study provides yet another important indicator — an extraordinary jump in trade wind intensity.

A primary driver of the strength of La Nina and its ability to transfer atmospheric heat into the oceans is the corresponding strength of the east to west trade winds blowing across the Pacific. A strong trade wind blowing over South America and shoving a huge pile of water across the Pacific from east to west generates vigorous upwelling. The strong upwelling, in turn, transfers relatively cool deep ocean waters to the surface, where they take up atmospheric heat. When the trades weaken, the opposite occurs and warmth builds up in the surface waters along with a corresponding shift to El Nino.

Given these factors, it is important to note that a recent study has found that the trade winds over the past decade have been their strongest since at least 1910 with the wind continuing to strengthen and intensify well into 2012.

EnglandFig1450

(Global temperature and wind anomalies with IPO overlay. Negative departures in the lower graph indicate unprecedented trade wind strength through 2012. Image and data source: England Study. Note — IPO stands for Interdecadal Pacific Oscillation, a condition related to El Nino and La Nina cycling over decadal periods.)

With such strong trade winds blowing over the Eastern Pacific, we are seeing an unprecedented transfer of heat from the atmosphere to the ocean (validated by both the trade winds data and the Argo float data). And given the strength of this transfer, we should be seeing some of the strongest La Ninas on record. But the ocean is now too warm for that, so instead we are seeing consistent La Ninas of normal caliber over the past 14 year period. A set of La Nina’s consistent enough to shift the Pacific Oscillation into a negative mode and, according to the England study, to temporarily suppress overall atmospheric warming by between .1 and .2 degrees Celsius.

And what this means is that when we see the period of consistent La Ninas end and shift to a time of more consistent El Nino events, that .1 to .2 degree Celsius heat transfer from atmosphere to ocean will stop and we will likely see a correspondingly rapid jump in air temperatures.

In a recent interview with The Guardian, England noted:

“the heat uptake is by no means permanent: when the trade wind strength returns to normal – as it inevitably will – our research suggests heat will quickly accumulate in the atmosphere. So global temperatures look set to rise rapidly …”

Model runs conducted by the England study that take into account trade wind strength and rate of heat transfer into the oceans show an extraordinarily vigorous increase in global temperatures of .2 C to .4 C by 2020 once the global trade winds return to normal. This, potentially very rapid, jump in atmospheric temperatures could be seen over a very short period during the next six years once the trade winds abate and the Eastern Pacific settles again into a more consistent period of El Ninos.

Models Show El Nino May be on the Horizon for 2014

Meanwhile, NOAA models are also beginning to hint that the hammer of Pacific Ocean heat may well be starting to fall. A majority of model runs, as of late January, were showing El Nino emerging in the Pacific by summer of 2014. Five models showed El Nino on the 9 month horizon, while two showed La Nina and three showed ENSO neutral conditions.

The NOAA Earth Systems Research Laboratory explained these findings:

Of the 10 nearest ranked December-January cases since 1950, FIVE rose to at least weak El Niño status within the next nine months (two within the next three months), while the count of weak or stronger La Niña rankings added up to two cases (1961 and 1967) after nine months. This confirms a noteworthy shift in the odds towards El Niño development in 2014 that was first pointed out two months ago. Compared to last month, the number of cases ending up as ENSO-neutral has dropped to 6 in three months, 5 in six months, and only 3 in nine months (September-October).

… While ENSO-neutral conditions are the safest bet for the next few months, a transition towards El Niño by mid- or late 2014 would not be surprising, perhaps even overdue.

How the Temperature Jump May Unfold

In light of the above reports, it is important to again state how rapid an atmospheric temperature increase of .2 to .4 C over the course of six years is. By comparison, the average decadal increase has been about .15 to .2 C for each 10 year period since the 1970s. So the England study suggests that atmospheric heating could double the usual rate between now and 2020.

What we would expect under such conditions is a gradual abatement of the current and unprecedented trade wind strength over the Pacific Ocean. As the trades weaken, the pool of very hot, deep water east of Australia and the Philippines would begin to shift eastward even as the Eastern Pacific took on uncharacteristic warmth. The long period of mixing with a rapidly heating atmosphere will have created an amazingly large and deep pool of hot water whose intensely high temperature anomalies become increasingly evident at the surface. The hot zone, in this case, exceeds even the extreme anomalies seen during 1998 for this critical region and a massive heat dump into the atmosphere begins.

At this point, single year variations above past record highs may reach or exceed +.1 C or more for multiple years running.

The unprecedented heat bleed from the Pacific doesn’t occur without a number of severe weather consequences. Especially under the gun for this, most recent, potential event of human caused climate change is California and the Desert Southwest. Having labored under drought since the early 2000s, the region sees a radical shift to unprecedented stormy conditions. During winter, a massive flow of heat driven moisture rides up from the Pacific and arcs over California carrying with it a stream of storms. The stormy period drags out for weeks, beginning to resemble the megastorm of centuries past. Cities and industries laboring under the strain of too little water see a sudden and radical, though brief, shift in the opposite direction. California, under the gun for tens of billions of dollars in damages from water shortages and drought instead falls under the gun for possibly hundreds of billions of dollars in storm damages.

El Nino related weather extremes crop up in Africa, Australia, the US East Coast, India, the Pacific Northwest, and in other locations. In all cases the extremes are far more radical than for a typical El Nino year.

Under such a regime, it is likely that global surface temperatures could reach 1 degree Celsius above the 1950 to 1980 average and 1.2 degrees Celsius above the average seen during 1880 by 2020. Very dangerous warming and related extreme weather would be well underway at this time under such conditions along a path toward an even more difficult and violent climate scenario to follow.

Links:

ESRL/NOAA

NASA GISS

Recent Intensification of Wind-Driven Circulation in the Pacific

Unprecedented Trade Wind Strength is Shifting Global Warming to the Oceans

The Pacific Arkstorm

California’s Superstorm

NASA’s Land-Ocean Temperature Index 

Arctic Heat Pushes Sea Ice to Record Low Levels in Early February

The Arctic Ice Blog

The NOAA Earth Systems Research Laboratory

Pace of Sea Level Rise Accelerates, Points Toward Increased Glacial Melt, Ocean Warming

MSL_Serie_MERGED_Global_IB_RWT_GIA_Adjust

(Image source: AVISO)

Since 1992, the average pace of sea level rise has remained constant at about 3 mm per year. This ongoing rise comes from a combination of thermal expansion of water as it warms due to human-caused global warming and contributions of melting ice in the form of glaciers.

Over the past decade, however, the pace of melt from glaciers in Greenland and West Antarctica have been on the rise. Their contribution to sea level and the overall pace of sea level rise is expected to grow as the glaciers continue to soften up and melt under the stress of human heating.

During the last two years, sea level rise tripled — jumping from an average rate of about 3mm per year to nearly one centimeter per year. So was this tripling due to increased glacial melt? The likelihood is that a moderate portion of this enhanced sea level rise came from jumps in glacial melt. But total volumes of melt are still not enough to account for the 2 cm of sea level rise over the past two years.

For the rest, we must look toward climate variability. In this case, volatility is probably a better word. During 2010-2011, more than half a centimeter of ocean water evaporated and ended up in the atmosphere. But the atmosphere couldn’t hold all of this extra moisture for long, so it ended up coming down in a series of unprecedented storms. This major event spawned epic floods and major rain events across the world. Over time, all this dumped water returned to the world’s oceans, re-contributing the more than half centimeter that was lost.

But even taking into account this half centimeter of water cycling in and out of the ocean, we still get a 5 mm annual rise in sea level since 2010. This, almost doubling, of sea level rise over the past three years is too early to count as an ongoing trend. But it may well be the result of enhanced glacial melt and steadily rising ocean heat content (and related thermal expansion) over this period.

Long Term Trend is Not Linear, Contains Risk of Outlier Events

Expectations are that sea level rise will drastically increase along with rising ocean temperatures and increasing glacial melt rates over the next century. The 3 mm per year rate of sea level rise would lead to a one foot increase were it to continue on until 2100. But this rate of rise is something we can hope for only if worldwide CO2 emissions stop now or very soon. Since this event is unlikely to happen, we can expect an amplification of sea level rise as ocean temperatures and glacial melt continue to increase.

At the 2010 to 2012 rate of sea level rise, oceans will have risen by more than 1 and a half feet come the end of this century. But, more likely, final sea level rise will be much closer to a meter by 2100 as glacial melt and thermal ocean expansion accelerate. This one meter rise would correspond closely to the one centimeter per year rise we’ve seen in 2011 and 2012, although greater than 1 centimeter per year averages will be more likely after 2040.

There is also, an outside potential for a major melt or ice sheet destabilization that will push sea levels much higher than 1 meter. Outside events of this nature are not taken into account in current climate models but are increasingly likely in worst-case scenarios produced by the IPCC (note, that IPCC does not model or predict for extreme responses like catastrophic ice sheet collapse). If such events were to occur, sea level rise could jump by 3 meters or more. The long-term likelihood of such events are difficult to predict. But they are worth noting, especially in the context of global temperature rises in the range of 2-6 degrees C over the next century.

Ocean Taking on More Heat Than Expected

With observations showing that more of the current GHG temperature forcing is going toward warming the oceans than previously anticipated, it is worth noting that, should this trend continue, sea level rise is at risk of being further amplified. Both thermal expansion and contact of warmer oceans with glaciers that lock in large ice shelves would be greater in such an event and would lead to higher rates of sea level rise.

Getting a better measure of how ocean and atmosphere heat balance changes in response to human caused forcings will be necessary if we are to have a more clear understanding of likely ocean changes and sea level rise over the next century.

Links:

Mean Sea Level Rise

New Oceans Study: Global Warming Accelerated in Last 15 Years

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