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Third Warm Kelvin Wave to Raise Extreme El Nino by Fall?

More fuel for El Nino’s fire and a record hot 2015 on the way…

Last week, a set of climate models predicted the emergence of a large and moderately strong westerly wind burst running against the trades associated with an eastward propagating cloudy and rainy phase of the Madden-Julian Oscillation (MJO). And, over the past few days a moderate strength, but very wide-ranging, westerly wind pattern appeared.

image

(A strengthening westerly wind burst over the Western Equatorial Pacific could produce a third warm Kelvin Wave and further heighten an El Nino that already has a potential to be very intense come Fall. Image source: Earth Nullschool.)

Today, 20 to 35 mile per hour westerly winds are prevalent along a 2,500 mile stretch of ocean running from just east of the Philippines, across an equatorial zone just north of New Guinea, and on eastward for hundreds more miles in the direction of the Date Line. The winds are associated with numerous low pressure systems developing both north and south of the Equator — their cyclonic wind patterns joining in a daisy chain like feature to drive a large synoptic westerly wind back-burst (WWB).

Over the next few days, winds within the zone are predicted to strengthen to near gale force intensity. But it’s the size of the zone that may have the greatest impact.

Strong, long-fetch westerlies in this region of the world have a tendency to push warm surface waters, now topping off at 31 degrees Celsius (and 1-2 C above the already hotter than normal 1979 to 2000 average), downward and eastward. This heat pump action generates what, in meteorological parlance, are known as warm Kelvin Waves. And warm Kelvin Waves are high energy fuel for strengthening El Ninos.

Two Warm Kelvin Waves

(Warm water propagation through the upper 300 meters of the central and eastern Equatorial Pacific serves as oceanic fuel for El Nino events. In the above graph by NOAA, not one but two warm Kelvin Waves are indicated — one peaking during April and May, and a second ongoing now. Will a significant westerly wind burst, now lighting off in the Western Pacific, generate a third warm Kelvin Wave by August? Image source: NOAA’s Climate Prediction Center.)

During mid-March, the Strongest Madden Julian Oscillation on record drove an extreme westerly wind burst (WWB) and produced a very strong Kelvin Wave. This Kelvin Wave ensured the progression to El Nino during 2015, an El Nino event that would have probably reached moderate strength by summer on the force of this single Kelvin Wave’s heating alone. An El Nino ensuring, when combined with the greenhouse gas heat forcing produced by humans, that 2015 would march into the record books as yet one more hottest year in the global climate record.

By early May, a second, albeit somewhat weaker, WWB generated another warm Kelvin Wave, heightening the potential for strong El Nino yet again. This time El Nino model forecasts picked up the doubled Kelvin Wave signal and began to produce some rather extreme predictions for El Nino come Fall. Late spring is an uncertain time for El Nino models due to an ocean tendency to cool down by September. So the impact of strong Kelvin Waves during spring can be somewhat muted. However, as June arrived, the model consensus for a strong El Nino emerging by Fall had solidified, if not along a range quite so extreme as some of the May numbers indicated.

Meanwhile, in the Central Pacific, anomalous warm sea surface temperatures were continuing to build. By mid-May, Central Pacific sea surface temperatures exceeded the moderate El Nino threshold of 1 C above average. By Monday, June 22, NOAA’s weekly El Nino statement had indicated that the Central Pacific region had warmed to a 1.4 degree Celsius positive anomaly. A level just 0.1 C short of strong El Nino intensity.

Adding a third significant Westerly Wind Burst on top of an already warming Equatorial Pacific throws yet one more variable into the dynamic El Nino forecast. A variable that could heighten the already strong potential for a major El Nino event late this Summer through to Fall. And one that could further heighten extreme global record hot temperatures during 2015. For the late June WWB is likely to produce an extraordinary third Warm Kelvin Wave, giving the currently strengthening El Nino yet one more shove toward increasingly extreme conditions.

Links:

NOAA’s Climate Prediction Center (Please support public, non-special interest based, science like the quality research and data provided to us daily by NOAA.)

NOAA’s weekly El Nino statement

Strongest Madden Julian Oscillation On Record

Madden-Julian Oscillation

Earth Nullschool

 

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New Study Finds Clouds are Amplifying Human Warming

The mysterious clouds.

For decades, science has been unable to nail down how clouds might change with human warming of the climate. Sure, we knew that added water vapor through a heating-increased amplification of the rate of evaporation and precipitation would likely impact cloud formation. But how would those physical alterations impact climate? Would an added darkening of the Earth through increased cloud cover provide a cooling effect and slow down the rate of human-caused warming (also called a negative feedback)? Or would the added water vapor aloft, itself a powerful greenhouse gas, provide an extra boost to the human heating engine (also called an amplifying feedback)?

The mainstream climate models thus assumed a zero to slightly positive heat feedback from clouds and relied on decadal verification runs to help test for accuracy. A kind of backwards checking that excluded values from clouds due to a lack of needed information.

Pyrocumulonimbus

(From the global climate change perspective, some clouds are worse than others. The above image shows a thunderstorm set off by massive wildfires blazing through the permafrost zone near Great Slave Lake on August 5 of 2014. A pyrocumulonimbus cloud or, colloquially, a fire thunderstorm. Image source: NASA.)

Confusionists Take Advantage of Cloud Uncertainty

It was an uncertainty hanging in the very air above us. An uncertainty many climate confusionists used to sow doubt over a broad range of issues involving how sensitive the Earth is to the human heat forcing. They often argued, through this scientific dim spot, that climate sensitivity was, indeed, quite low and that we had very little to be concerned about regarding an immense dumping of heat trapping gasses into the atmosphere that is now at least 6 times faster than at any time in the deep history of life on Earth.

The shady clouds, in other words, would save us from ourselves.

Not so fast, said Dr. Andrew Dressler who in this paper and this paper recently defended consensus climate science from the cloudy claims of confusionists. Dressler, like mainstream climate science, assumed at least a small degree of positive feedback from changes to clouds and atmospheric water vapor loading. And his observational findings were consistent with an equilibrium climate sensitivity (ECS), or a one century rate of warming, in the range of 2.0 to 4.5 degrees Celsius for each doubling of CO2 (consistent with a multi-century warming [ESS] in the range of 4 to 9 C for each doubling of CO2 — or about a 6 C average).

New Study Finds Changes to Clouds are an Amplifying Feedback

But now, a new study has found that the picture is not quite so rosy as some claimed. The study, led by Dr. Kevin Trenberth, found that net changes to clouds and related additions of water vapor to the upper atmosphere is a positive or amplifying feedback to human caused warming. In other words, the way human heat alters clouds and the related hydrological cycle results in yet more heat being trapped by the Earth System.

This confirms Dr. Dressler’s work and raises a rather unpleasant question — if we have an added heat feedback from clouds under a regime of Earth Systems warming, then how strong is it?

Trenberth notes in an interview published today in The Guardian:

What we do find is that if one looks at tropospheric average temperature rather than surface temperature, then there is a much stronger relationship with energy flow at the top of the Earth’s atmosphere. We are able to find a water vapor signal that is clearly a positive feedback.

Climate Sensitivity Needle May Tilt Toward Upper Range of Estimates

This is somewhat unhappy news.

What it means is that the Earth System is at least as sensitive as climate models suggest. But, even worse, there is a chance that the Earth System may be closer to the upper range of climate sensitivity estimates. It means that accumulation of heat in the atmosphere, in glaciers and in the ocean may happen somewhat faster than consensus models predict and that geophysical changes may, consequently, be greater and more catastrophic.

Whether model simulation of climate sensitivity will need to be altered has not, as yet, been determined. The study is now very new and it will take some time for the more recent data to wash out in the model projections.

But what can be plainly stated is that fossil fuel industry funded voices of false comfort have again been proven dreadfully wrong and that there is some risk that the situation may be even more dangerous than current science anticipates. As such, there is absolutely no reason for further delays in policy action and a very rapid draw-down to zero human carbon emissions.

Links:

Climate Variability and Relationships Between Top of Atmosphere Radiation and Temperatures on Earth

Changes in Water Vapor and Clouds are Amplifying Global Warming

A Determination of the Cloud Feedback from Climate Variations Over the Past Decade

Clouds and The Earth’s Energy Budget

NASA

Hat Tip to TodaysGuestIs

Record Warm World’s ‘Weird’ 2015 El Nino Sees Westerly Gales, Growing Kelvin Wave

“The 2015 El Nino is finally here, but it’s weak, weird and late,” said Mike Halpert, deputy director of the Climate Prediction Center last week.

And the current El Nino is certainly an odd bird. According to reports from NOAA and the National Weather Service, the center of highest sea surface temperatures for the El Nino this year is offset westward — coming closer to the date line than it typically does. This is a weird heat disposition for El Nino which is, at least, a mid ocean event and often pushes warming well across the Pacific to South American shores.

image

(Pacific sea surface temperature anomaly [SSTA]. Note the hot water pools off both Australia and North America. These zones are joined by a vast blanket of warmer than average waters arranged diagonally across the Pacific from SW to NE. This disposition includes the warm anomaly along the Equator which is hot enough to reach weak El Nino status. But the disposition of sea surface temperatures throughout the Pacific, with highest equatorial anomalies near the date line and warmer spikes near Australia and the North American West Coast is unusual. SSTA graphic provided by Earth Nullschool. Data Source: Global Forecast System Model and NCEP.)

It’s also late in coming, as typical El Ninos have tended to arrive in full form during late fall or early winter. A Christmas-time warming of waters off the West Coast of South America was a traditional call-sign for El Nino and one that resulted in its name — which is Spanish for “The Christ Child.” Late winter and early spring are more typical times for the formation of deeper warmer water that may trigger an El Nino later in the year but often do not herald a fully-developed event (see What is El Nino? for more related information).

Lastly, the El Nino is currently rather weak — barely meeting a requirement for El Nino from NOAA and still not reaching the threshold that Australia’s Bureau of Meteorology applies.

But despite all this relative oddity, the 2015 El Nino is here. And it appears to be growing.

Intense West Wind Back-burst Coincident with Powerful Cyclone Formation

For earlier this week strong westerly winds began to roar against the typical flow of the trades along the Equator. The west wind back-bursts (WWB) push warmer West Pacific waters eastward and downward, enhancing the sea surface temperature anomaly spikes that fuel El Nino.

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(Very strong West Wind Back-Burst hosting 85 kph 10 minute west wind at 7.45 South Latitude on early March 11. Image source: Earth Nullschool.)

As of early Wednesday, March 11, these west winds had formed a gale force wall stretching just past the date line from about 5 North Latitude to 10 South Latitude. A gale driven by parallel cyclones — a weaker system to the north (Bavi) and the newly gathering Pam, which may challenge south Pacific records as the strongest storm ever to form in that region. In the above graphic we see a related ten minute sustained WWB of a rather extraordinary 85 kilometers per hour (about 50 mph) along the 7.45 degree South Latitude line.

Strengthening Kelvin Wave in a Record Warm World

Just before the formation of these strong westerlies, sub-surface temperatures also began to spike. A warm Kelvin wave that had already started its run beneath the sea surface, as of March 4, was beginning to show signs of strengthening well in advance of the added shove coming from the vigorous WWB shown above.

Strengthening Kelvin Wave

(A new Monster Kelvin wave? Sub surface temperature anomalies are again entering the far above normal range for the Equatorial Pacific. Image source: Climate Prediction Center.)

Peak temperatures in the wave as of a week ago had hit more than +6 C above average. A heat signature that is starting to look, more and more, like the very powerful Kelvin Wave of early 2014 that belched so much warmth into the atmosphere and likely contributed to both the current strongly positive PDO as well as 2014’s new record high temperatures.

An event that top ocean and atmospheric scientists Kevin Trenberth and Axel Timmerman attribute to signalling a possible start to much more rapid atmospheric temperature increases.

The Kind of Mid-Ocean Event That Some Scientists Say we Should See More of

If this is the case, then what we may be seeing is a slow start to an El Nino that could be much stronger and longer than expected. Last year’s intense Kelvin Wave may have simply been preparation for a slowly building event in conjunction with what was, during December, a record broader warming of the Pacific called positive Pacific Decadal Oscillation (PDO). Some model runs, especially those at Australia’s BoM, appear to have picked up this track.

In addition, NOAA sea surface temperature models now are predicting continued Central Pacific Warming (CPW) in association with the current El Nino over the coming months. If this El Nino continues to progress along CPW warming lines, then it is likely to be more indicative of what Japanese scientists call an El Nino Modoki event:

El Nino Modoki

(Sea surface temperature signature of an El Nino Modoki, which is closer to what we are seeing now, even if the higher temperature levels are currently shifted more toward the Date Line. Image source: Japan Agency for Marine-Earth Science.)

During recent years, some scientific reports have indicated that Central Pacific Warming or El Nino Modoki will be more prevalent as a result of human-caused climate change. Study authors Tong Lee and Michael J McPhaden, in the 2010 paper entitled Increasing Intensity of El Nino in the Central Equatorial Pacific note that increases in Pacific Ocean temperatures are primarily expressed through more intense warming of the central regions:

Satellite observations suggest that the intensity of El Niño events in the central equatorial Pacific (CP) has almost doubled in the past three decades, with the strongest warming occurring in 2009–10. This is related to the increasing intensity as well as occurrence frequency of the so-called CP El Niño events since the 1990s. While sea surface temperature (SST) in the CP region during El Niño years has been increasing, those during neutral and La Niña years have not. Therefore, the well-documented warming trend of the warm pool in the CP region is primarily a result of more intense El Niño events rather than a general rise of background SST.

If so, it seems possible that global warming may well be influencing the rather strange El Nino evolution we are witnessing now.

In any case, Central Pacific Warming El Ninos have a somewhat different impact than Eastern Pacific Warming El Ninos. For one, they tend to ramp up, rather than cool down North Atlantic Hurricanes. They also tend to result in more, not less, drought for the US West Coast. For India, mid-ocean warming of the kind we are seeing now can result in an enhanced disruption of the Asian monsoon — kicking off drought and related food security risks.

Tong Lee and Michael J McPhaden continue by adding:

…. the amplitude of this new type of El Niño has increased in recent decades (Lee and McPhaden 2010). For convenience, hereinafter we refer this new type of El Niño as to CP warming (CPW). Compared with the canonical EPW, the CPW exhibits distinctly different impacts on worldwide climate. For example, the CPW shifts the anomalous convection westward and usually forms two anomalous Walker circulations in the tropical Pacific (Ashok et al. 2007; Weng et al. 2007; Weng et al. 2009). The westward displaced convection was suggested to be more effective in causing Indian drought (Kumar et al. 2006). The CPW increases hurricane frequency both in the Atlantic Ocean (Kim et al. 2009) and western North Pacific (Chen and Tam 2010), and also shifts tropical cyclone tracks in the western North Pacific (Hong et al. 2011).

But the authors’ research doesn’t directly point toward the odd seasonal change we are witnessing now, nor the off-setting of the initial hot pool about 1,500 kilometers further west than even during a typical El Nino Modoki event. For this reason, our ‘weird’ El Nino and equally weird and warm Central Pacific bear close watching.

Links:

El Nino Finally Here, But it’s Weak, Weird, and Late
NOAA
National Weather Service
What is El Nino?
NOAA’s ONI Index
BoM ENSO Wrap-up
Earth Nullschool
Global Forecast System Model
NCEP
Pam at Category 5 Strength
Warming Pacific Drives Global Temperatures
Bad Climate Outcomes
2015 El Nino to Bring Back-to-Back Hottest Years on Record?
Increasing Intensity of Central Pacific El Nino — Links to Climate Change
Japan Agency for Marine-Earth Science
El Nino Declared as Climate Scientists Watch on With Amazement

Hat tip to Phil

Hat tip to Wili

Hat tip to Timothy Chase

California Experiencing Driest Year on Record, Epic Drought to Persist or Intensify Through Summer, Godzilla El Nino Waits in the Wings

8.83 inches. That’s the total average precipitation accumulation for the state of California so far for the first four months of this year. Out of the entire climate record, this paltry accumulation is less than that received during any similar period of any year since 1895.

Overall, rainfall totals throughout the state remained below 26 percent of typical levels for this time of year. And with California entering its third year of drought, the state would have to receive an average of 53 inches between now and October, more than 10 inches of rainfall each month, to break the current and very extreme ongoing drought.

May 6 drought monitor

(Drought monitor color graphic of California drought as of May 6. Tan = moderate drought. Orange = severe drought. Red = extreme drought. Dark Red = exceptional drought. Image source: Drought Monitor.)

As of late April, the drought had expanded to cover every corner of the state leaving not an inch of this critical agricultural region untouched. Drought continued to intensify, bringing with it water stress, cracked soil, crashing reservoirs and heavy strains to farms, businesses, cities and individuals. By May 6, fully 77 percent of California stifled under severe or extreme drought conditions.

The drought has become so severe that water-strapped cities like Santa Cruz have resorted to the most dire measures, including rationing, to husband dwindling water supplies. Last week, the city, which depends on some of the most vulnerable and thinly-stretched water resources in the state, announced a number of severe fines to water consumers exceeding assigned usage levels. The fines could quickly double, triple, or even quadruple water costs for any non-farm water consumer within the city.

Across the State, various desperate water conservation regimes have been put in place with the Federal Government announcing earlier this year that it would be forced to stop water allocations to farmers in an unprecedented move to stave off further declines in stores.

US Seasonal Drought Outlook

(US Seasonal Drought Outlook. Image source: CPC.)

Unfortunately, the persistent high pressure blocking pattern off the US West Coast, which has hovered in the same region for more than a year, remains in place even as it continues to deflect rain-bearing storms north toward the Washington and Canadian coasts.

This pattern — arising from a set of abnormal atmospheric conditions including added heating through human-caused warming and a Jet Stream that has the tendency to become stuck more and more often as sea ice erodes — results in a high likelihood that drought will remain or intensify for California and much of the US Southwest throughout this summer.

Climate Prediction Center analysis, shown above, projects that the current California drought will persist or worsen for the entire state through at least July 31rst. If relief does come, it will arrive many months from now. For the most likely chance for a change in the weather doesn’t appear until fall and winter of 2014. And this potential brings with it the risk for a radical switch to yet another damaging climate extreme.

Hoping For El Nino is Like Praying to Godzilla

Yesterday’s report from NOAA indicating a near 80 percent chance of El Nino by the end of this year provided some hope for additional rainfall after what is expected to be a very dry and difficult summer. But given current atmospheric conditions, the El Nino event would have to be in the moderate-to-strong range to both overcome what is a demonically persistent blocking pattern and to deliver enough moisture to make up the severe rainfall deficit. Anything less would be too weak to cure the current drought. But something stronger may well kill the patient.

Unfortunately, there remains a substantial risk that the 2014-2015 El Nino event could be a Godzilla of a thing — a monstrous outburst of the extreme ocean heat storage of the past 16 years that Dr. Kevin Trenberth has warned could well come back to haunt us. A record high ocean heat content that is out there, lurking in the Pacific Ocean even now. And it’s the potential that this heat will hit the surface with a severity rivaling or even exceeding the epic 1998 event that should well be cause for a different kind of concern.

ohc-2013

(Ocean heat content through 2013. Image source: Reanalysis of Global Ocean Heat Content.)

In such an instance, the onrush of heavy rains would be less a relief and more a switch from extreme drought to extreme flood. During the 1998 event more than 20 California counties were declared disaster areas due to the sudden deluge. But with human warming amping up the hydrological cycle by more than 6% and with such a large and vicious store of ocean heat waiting to be released, a severe El Nino at this stage might look more like an Arkstorm — an event which could dump many feet of rain over a period of weeks.

On the other hand, if the El Nino fizzles into only a minor event and that massive ocean heat store decides to lay in wait for another year or two or three, California is much more likely to remain locked in a continued multi-year dry pattern. So the best California could hope for is to thread an El Nino needle and receive a just-right moderate to strong El Nino. But with the current climate regime favoring extremes, the possibility for such a just-right occurrence is quite a bit lower than either the Godzilla or the fizzle.

In any case, both added heat and dryness are set to intensify over coming years and decades for California. This ongoing ratcheting is the direct result of human-caused climate change. A result that will either be bad or terrible depending on whether or not we decide to rapidly reduce and eliminate our greenhouse gas emissions.

Links:

Climate Outlook for Central California

Drought Monitor

CPC

Santa Cruz Rations Water

Farmers to Receive No Central Valley Water This Year From Feds

Dangerous Progress Toward Strong El Nino Continues

Reanalysis of Global Ocean Heat Content

 

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