Guest post by Bob Tisdale
This post will serve as the Preliminary Sea Surface Temperature Anomaly Update for June 2012, since we’ll be using preliminary June 2012 data in it. Last week ended on June 30th, so the preliminary data should be close to the official June data, which does not come out until Monday July 9, 2012. Refer to the schedule on the NOAA Optimum Interpolation Sea Surface Temperature Analysis Frequently Asked Questions webpage.
Anthony Watts often starts a post with, “I get mail.” And sometimes I get mail from Anthony Watts. This post takes a look at the curious sea surface temperature anomaly patterns Anthony and Roger Sowell expressed interest in.
Many people, including me, have the Unisys daily maps of sea surface temperature anomalies as one of their browser favorites. Figure 1 shows the map dated July 1, 2012. I also take a look at the Unisys sea surface temperature anomaly animation at least once a week. As of today, there’s cool waters flowing toward the central tropical Pacific out of the North Pacific, and in the northeastern South Pacific, there’s the pocket of warm waters off the coast of South America feeding northward. This will be an interesting El Niño to watch.
The map shows very low sea surface temperature anomalies in the Bering Sea. For those of you who don’t recall where the Bering Sea is, it’s south of the Bering Strait between Alaska and Russia and north of the Aleutian Island chain. In the eastern North Pacific, there’s a pattern that many would consider a negative Pacific Decadal Oscillation (PDO) spatial pattern. Toward the west, though, during a negative PDO pattern one would expect positive anomalies in the western boundary current extension east of Japan called the Kuroshio-Oyashio Extension or KOE. But the typical PDO pattern that people look for is stronger in boreal winter. Right now the North Pacific is transitioning from the aftereffects of the 2011/12 La Niña to the upcoming El Niño.
Are the sea surface temperature anomalies in the Bering Sea unusually cool? Looking at Figure 2, the sea surface temperature anomalies for the Bering Sea have been cooler in the past, most recently during the 1998/99/00/01 La Niña. Is the recent drop caused by the unusual amount of sea ice packed to the north of Bering Strait? Dunno. One thing is certain, sea surface temperature anomalies for the Bering Sea have been cooling steadily since 2003-04.
And that’s consistent with the entire North Pacific, Figure 3. Sea surface temperature anomalies, based on the smoothed curve, peaked there in 2004/05 and have been cooling since–with an ENSO-related wiggle or three. And the North Pacific is a big chunk o’ water.
Referring back to the map in Figure 1, over in the North Atlantic, there’s that trough of cool anomalies. It stretches northeast from the Gulf of Mexico to the North Sea and Baltic Sea. I don’t recall that pattern in any of the sea surface temperature anomaly animations I’ve created. Then again, most of those have been based on the Reynolds OI.v2 data, which start in November 1982. I took another look at the animation of Global sea surface temperature anomalies I had prepared three years ago that’s posted on YouTube. I didn’t see that same cool trough in the North Atlantic. And I had used a contour interval of 0.2 deg C in the animation to make patterns like the trough stand out. That doesn’t mean the cool trough hasn’t existed before; it just hasn’t shown itself (or shown itself as clearly?) in the last 30 years.
But you always have to keep in mind that the color scaling of the Unisys sea surface temperature anomaly maps are weighted toward blues and greens, which most of us associate with negative (cool) sea surface temperature anomalies. The light blues in the Unisys maps include anomalies as high as +1 deg C, and greens extend up to +2 deg C, where most presentations are showing yellows, oranges and reds at those levels. That’s why I also have the map at Australia’s EldersWeather webpage as a favorite. See Figure 4. Its color scale is similar to the one I use in the monthly sea surface temperature anomaly updates. It helps to put things back in perspective. The cool trough in the North Atlantic is still there, but it’s not as impressive.
What stands out more in that map are the high sea surface temperature anomalies along the east coast of North America, north of North Carolina, that reach up toward southern Greenland. They formed over the past couple of months. Part of that is caused by a residual seasonal cycle in the anomalies, and part of it is “weather-related” warming. Figure 5 shows the time-series graph of sea surface temperature anomalies for the Northwest North Atlantic–refer to the coordinates on the graph. It captures the hotspot from Newfoundland and Labrador to southern Greenland. There have been warmer sea surface temperature anomalies there, but that was the summer following the 2009/10 El Niño. We’ll just have to see where they wind up and how long they persist this year.
The recent elevated Northwest North Atlantic sea surface temperature anomalies did not have a major impact on the sea surface temperature anomalies for the North Atlantic as a whole, Figure 6. The seasonal upward swing there is not abnormal.
Since the decrease in North Pacific sea surface temperature anomalies (Figure 3) was much greater than the rise in the North Atlantic data (Figure 6), the Northern Hemisphere sea surface temperature anomalies, Figure 7, dropped in June 2012. But that was countered by the increase in the Southern Hemisphere data, Figure 8. (If NOAA updated their base years for anomalies, some of those seasonal swings would decrease.) The offsetting chnages in hemispheric data caused there to be basically no change in Global sea surface temperature anomalies, Figure 9. They dropped about -0.01 deg C—as I said, basically no change in Global sea surface temperature anomalies.
The preliminary monthly NINO3.4 sea surface temperature anomalies for June (0.45 deg C) are just shy of the 0.5 deg C threshold of an El Niño event. NINO3.4 sea surface temperature anomalies are a commonly used index for the frequency, magnitude and duration of El Niño-Southern Oscillation (ENSO) events. See Figure 10. And the weekly NINO3.4 sea surface temperature anomalies (Figure 11) for the week centered in Wednesday June 27thare at 0.73 deg C. That’s well into weak El Niño range. I’ve also included NINO1+2 sea surface temperature anomalies in Figure 11. The NINO1+2 region is bordered by the coordinates of 10S-0, 90W-80W, which is centered just south of the equator in the far eastern tropical Pacific. As you can see, they’ve been elevated for a number of months. The 2012/13 El Niño is starting as an East Pacific El Niño, which are typically stronger than Central Pacific El Niño events. We shall see how well the upcoming El Niño maintains that “typical” ENSO characteristic.
Figure 12 is a graph of weekly Global sea surface temperature anomalies centered on Wednesday June 27th. They’re making their wiggly transition from their responses to the La Niña and to the upcoming El Niño. Something stands out for me in Figure 12 and in the monthly global sea surface temperature anomalies, Figure 9. Note how the La Niña-related seasonal minimum straddling 2011/12 is noticeably cooler than the seasonal minimum of 2010/11. Yet the 2010/11 La Niña was much stronger than the 2011/12 La Niña.
And the last two illustrations show the preliminary June sea surface temperature anomaly graphs for the East Pacific and for the rest of the world, the Atlantic-Indian-West Pacific Oceans. Those two subsets capture the data from pole to pole. I present the global data divided into those two subsets in my monthly sea surface temperature updates for very obvious reasons. The East Pacific sea surface temperature anomalies from pole to pole haven’t risen in 30 years, and that dataset represents about 1/3rd of the surface area of the global oceans. You could cut and paste a Super El Niño at the end of it and the trend would still be flat. Then there’s the “rest-of-the-world” data, which represents the other 2/3rdsof the global ocean surface area. It rose in very clear steps over the past 30 years. The steps are caused by major El Niño events that are followed by La Niña events, and those are El Niño events that also have not been counteracted by the effects of explosive volcanic eruptions, which is what happened in 1982/83. Sea surface temperatures in the Atlantic-Indian-West Pacific oceans don’t rise between the major El Niño events, even with the effects of a rising Atlantic Multidecadal Oscillation. And that means the sea surface temperatures for the South Atlantic, Indian and West Pacific Oceans decrease between those events. That and the fact that the East Pacific sea surface temperature anomalies have actually decreased over the past 30 years are hard to explain with the anthropogenic global warming hypothesis, especially when the climate models used by the IPCC don’t reproduce those global sea surface temperature patterns. Those models show no skill whatsoever.
WOULD YOU LIKE TO UNDERSTAND WHY THE ATLANTIC-INDIAN-WEST PACIFIC DATASET SHIFTS UPWARD IN RESPONSE TO MAJOR EL NIÑO EVENTS?
Over the past three years, in so many posts it’s not practical to link them here, I’ve presented the El Niño-Southern Oscillation (ENSO)-related processes that cause the blatantly obvious upward shifts in sea surface temperature anomalies for the Atlantic, Indian and West Pacific data shown above. I’ve also explained why the East Pacific shows no warming over the past 30 years. You’re welcome to use the search function on this webpage.
In my upcoming book, I go into lots more detail about how ENSO causes those upward shifts. I’m hoping to publish it in late July, early August of this year. The only things slowing down the process are the new chapters I’ve added under the section of general ENSO discussions, and those are discussions I have not posted on my blog.
The Reynolds Optimally Interpolated Sea Surface Temperature Data (OI.v2) are available through the NOAA National Operational Model Archive & Distribution System (NOMADS) website.