I returned to a recent post at SkepticalScience to examine what the author had to say about two papers: Meehl et al (2011) and Meehl et al (2013). [We discussed Meehl et al (2013) here.] I am now convinced SkepticalScience should be renamed UtterNonsense or TheCluelessLeadingTheClueless. The SkepticalScience post I’m referring to is A Looming Climate Shift: Will Ocean Heat Come Back to Haunt Us?, and the author is Rob Painting.
The first comment on the thread reads:
Can you say how strong the empirical evidence is for rapid warming to start in the near future? As a non-scientist climate change communicator I’d like to let people know what the balance of evidence is without being too alarmist.
The resident expert on coupled ocean-atmosphere circulation at SkepticalScience, the author of the post Rob Painting, replied (my boldface):
Individuals will make their own decision as to whether they find this information alarming or not. The consequences of a shutdown of the wind-driven ocean circulation could be very profound. As for previous behavior of the Interdecadal Pacific Oscillation, given that many readers will not be familiar with this index – I’m writing a follow-up to this post.
“The consequences of a shutdown of the wind-driven ocean circulation could be very profound”????? He has got to be kidding.
The tragedy: The “climate change communicator” who asked the question, someone who by their own admission does not have a scientific background, actually thanked Rob Painting for the answer. Will the “climate change communicator” now broadcast that nonsense through his communication channels?
The most telling part: No one else commenting on the thread questioned Rob Painting’s statement.
How strange is the phrase “shutdown of the wind-driven ocean circulation”? A Google search with that phrase in quotes presented results only from SkepticalScience. (And now results appear in response to this post.)
Anyone who proposes a shutdown of wind-driven ocean circulation has no clue whatsoever about what causes it.
Wind-driven ocean circulation results from the temperature differences between the tropics and the mid-latitudes, and those temperature differences are caused by the sun heating the tropics more than it heats the mid-latitudes. Since the surface of the ocean is warmer in the tropics than at mid-latitudes, more convection occurs in the tropics. In other words, the air is rising in the tropics. Surface winds blow from the mid-latitudes to the tropics to replace the rising air. The other component is the rotation of the Earth. It causes a phenomenon called the Coriolis effect, which deflects the equatorward traveling winds to the west. Those trade winds, as they’re known, blow across the surface of the tropical oceans and cause the currents north and south of the equator to flow from east to west.
Note: To reduce the number of components, I excluded surface pressures from the preceding discussion. But we all know that surface winds blow from areas of higher pressure to those with lower pressures. And I also excluded El Niño- and La Niña-related discussions.
For wind-driven ocean circulation to shut down, is Rob Painting suggesting the waters in the tropics will no longer be warmer than they are in the mid-latitudes? And is he also suggesting the Earth will stop rotating? Those things would have to occur for his proposed shutdown to occur. Considering that SkepticalScience is an alarmist website, is he suggesting that all this will be caused by increases in manmade greenhouse gases?
For those who’d like a more detailed introduction to what causes the trade winds to blow and for the surface currents to flow, here’s a chapter from my book Who Turned on the Heat? Sometimes a few illustrations help.
3.2 Pacific Trade Winds and Ocean Currents
Trade winds are the prevailing surface winds in the tropics. They’re called easterlies because they blow primarily from east to west. In the Northern Hemisphere, the trade winds travel from the northeast to the southwest, and they travel from southeast to northwest in the Southern Hemisphere.
The trade winds blow because the surface temperature is warmer near the equator than it is at higher latitudes. Refer to Figure 3-2 for the annual 2011 zonal-mean sea surface temperatures for the Pacific Ocean.
Warm, moist air rises near the equator. This upward motion draws replacement surface air from the north in the Northern Hemisphere and from the south in the Southern Hemisphere. In other words, the air at the surface is being drawn toward the equator due to the updraft there. In turn, the equatorward surface winds need to be replaced, and that cool, dry air is drawn down from higher altitudes at about 30N and 30S. Upper winds traveling poleward from the equator complete the circuit. That circuit is called a Hadley Cell. See Figure 3-3. Because the Earth is rotating, the equatorward surface winds are deflected toward the west by the Coriolis force.
We can explain the Hadley Circulation another way, if you prefer. We’ll start again near the equator where warm, moist air rises. It travels poleward at an altitude of 10 to 15 kilometers (32,800 to 45,800 feet) losing heat and moisture along the way. The cooler, dryer air then drops back toward the surface in the subtropics at about 30N and 30S. The surface winds then complete the circulation pattern. If the Earth was not rotating, the tropical surface winds would be out of the north in the Northern Hemisphere and out of the south in the Southern Hemisphere. Because the Earth is rotating, however, the tropical surface winds—the trade winds—are deflected toward the west.
The prevailing tropical winds are, therefore, from east to west. They blow across the surface of the tropical Pacific Ocean, dragging the surface waters along with them. There are two surface currents as a result, traveling from east to west, one per hemisphere. They are logically called the North and South Pacific Equatorial Currents. There is a smaller surface current flowing between them that returns some of the water back to the east and it’s called the Equatorial Countercurrent. See Figure 3-4.
The Equatorial Currents carry the waters across the tropical Pacific. Then they encounter Indonesia, which restricts continued flow to the west. Some of the water is carried through all of the islands to the Indian Ocean by a surface current called the Indonesian Throughflow. As noted above, a little of the water is carried east by the Equatorial Countercurrent. The rest of the water is carried poleward. The overall systems of rotating ocean currents in the Northern and Southern Hemispheres are known as gyres. Gyres exist in all ocean basins. The ones in Figure 3-5 are called the North Pacific Gyre and the South Pacific Gyre.
The NASA Ocean Motion website is a great resource for entry-level discussions of ocean currents. Refer to their Home and Wind Driven Surface Currents: Equatorial Currents Background web pages. Take a tour; there’s lots of interesting information there.
[End of Chapter 3.2 of Who Turned on the Heat?]
Who Turned on the Heat? is a detailed presentation of the coupled ocean-atmosphere processes most persons refer to as El Niño and La Niña. Known collectively as the El Niño-Southern Oscillation (ENSO), they are the second strongest of the natural phenomena that have annual and multiyear effects on global climate—the strongest are explosive volcanic eruptions, which can overwhelm the effects of even the strongest El Niño. The recent example of that is the eruption of El Chichon—it counteracted the very strong 1982/83 El Niño.
The ocean heat content records and the satellite-era sea surface temperature records indicate that the processes of El Niño and La Niña events are responsible for much of the warming of the global oceans. That’s right—the instrument temperature record indicates the oceans warmed naturally. If this topic is new to you, refer to my illustrated essay “The Manmade Global Warming Challenge” [42MB].
Who Turned on the Heat? begins with entry-level discussions, like Chapter 3.2 above. A preview is available here [4MB]. Who Turned on the Heat? is only available in pdf form here, for a price of US$8.00.
I’m working on a new introductory post to Who Turned on the Heat?, because I’m no longer pleased with the original Everything You Ever Wanted to Know About El Niño and La Niña.
In the past, I’ve tried to ignore what SkepticalScience’s resident expert, Rob Painting, has had to say about ENSO and its related coupled ocean-atmosphere processes. Try as I may, I do wind up talking about them occasionally. But I couldn’t overlook his statement, “The consequences of a shutdown of the wind-driven ocean circulation could be very profound.” And I find it quite remarkable that the denizens of SkepticalScience bought it—or just as likely, they elected to ignore it.
Rob Painting ended that comment with:
As for previous behavior of the Interdecadal Pacific Oscillation, given that many readers will not be familiar with this index – I’m writing a follow-up to this post.
We discussed at length what the Interdecadal Pacific Oscillation was, and what it wasn’t, in the post Meehl et al (2013) Are Also Looking for Trenberth’s Missing Heat. I’m patiently waiting for Painting’s follow-up post. It should be entertaining.