As noted in the July 2013 Sea Surface Temperature (SST) Anomaly Update, the extratropical North Pacific sea surface temperature anomalies (24N-65N, 100E-100W) made an unexpected surge in July 2013. NOAA may make a fuss about this in their State of the Climate Report this month, so I figured I’d better address it.
Before we begin, I first want to note that the Pacific sea surface temperature anomalies, as a whole, still show little to no warming over the past 20 years. Refer to Figure 1. But the models prepared for the IPCC’s upcoming 5th Assessment Report have simulated that the Pacific sea surface temperatures should have warmed about 0.4 deg C in the last 2 decades.
Figure 1
People are going to try to blame the recent warming event in the extratropical North Pacific on human-induced global warming, but before they do that, they’ll need to explain why the Pacific as a whole hasn’t warmed in 2 decades.
THE EXTRATROPICAL NORTH PACFIC WAS WARM IN JULY 2013
There’s no doubt that the sea surface temperature anomalies for the extratropical North Pacific, based on the Reynolds OI.v2 data, are at record levels. See Figure 2.
Figure 2
Note: The seasonal cycle in the sea surface temperatures there peaks in August, so that’s not the warmest the sea surface temperatures (not anomalies) have been in extratropical North Pacific, but, unless there’s a drop in the anomalies this month, expect the alarmists at NOAA to be chiming in on that a month from now.
Notice, however, how relatively flat the sea surface temperatures had been in the extratropical North Pacific since the early 1990s—prior to the surge. In fact, as shown in Figure 3, the sea surface temperatures of the extratropical North Pacific have warmed at a very slow pace (0.029 deg C/decade) even with the July 2013 reading, while the models indicate it should have warmed at a rate that is almost 7.5 times faster.
Figure 3
Looking at the weekly data since January 2001, Figure 4, the sea surface temperature anomalies for the extratropical North Pacific during the week of July 31, 2013 were also at their warmest—though not too much higher than the value reached in August 2004. And for those interested, the seasonal cycle in the anomalies there also typically peaks in August.
Figure 4
THE CARRY OVER TO THE NORTH PACIFIC AND THE PACIFIC AS A WHOLE
With a spike that large, the sea surface temperature anomalies of the entire North Pacific are also at record levels (Figure 5).
Figure 5
The Pacific as a whole (Figure 6) also showed a surge.
Figure 6
The tropical Pacific is experiencing ENSO-neutral conditions (not an El Niño and not a La Niña), but the recent rise in Pacific sea surface temperature anomalies (Figure 6) looks like the start of an El Niño event. (And for those wondering, sea surface temperature anomalies in the South Pacific cooled very slightly in July 2013.)
A REMINDER OF THE SOUTH ATLANTIC
When I saw the surge in the North Pacific this month, I was reminded of the curious surge in the South Atlantic sea surface temperature anomalies a few years ago. Refer to Figure 7. Other than the dip and rebound in the early 90s and second smaller dip in the late 1990s, sea surface temperature anomalies in the South Atlantic remained relatively flat from the late 1980s to 2008. Then in early 2009 there was a sudden upward shift. Sea surface temperature anomalies remained elevated for a few years in the South Atlantic and then dropped back to previous levels.
Figure 7
I have yet to find a paper that explains that sudden surge in South Atlantic sea surface temperatures, but I also stopped looking for an explanation a few years ago.
SURGE IN NORTH PACIFIC ALSO APPEARS IN NOAA’s ERSST.v3b DATA
Figure 8 compares the sea surface temperature anomalies for the extratropical North Pacific using the NOAA’s Reynolds OI.v2 data and their ERSST.v3b reconstruction. The ERSST.v3b data is used in the NOAA/NCDC combined global land air plus surface temperature anomaly product. While the Reynolds OI.v2 data is more volatile (a function of the satellite data it also uses), the sudden surge in the extratropical Pacific sea surface temperatures also appears in the ERSST.v3b data, which is based only on measurements from ship inlets and buoys (fixed and floating).
Figure 8
In Figure 9, the extratropical North Pacific data from the ERSST.v3b reconstruction is presented since the start of the dataset in 1854. The data is very volatile there, and it’s prone to sudden shifts and spikes. In addition to the recent spike, the one in the late 1960s also stands out.
Figure 9
There are two very pronounced multidecadal cooling periods in the sea surface temperature anomalies of the extratropical North Pacific. Of course, as shown in Figure 10, the climate models prepared for the IPCC’s upcoming 5th Assessment Report cannot simulate those cooling periods. As a result, they fail to properly simulate the warming that took place, when it took place. And they definitely failed to capture the upward shift in the late 1980s, which was caused by a shift in wind patterns. That well-known shift was then followed by a relatively flat temperature period (Refer back to Figure 3), until the recent upward spike.
Figure 10
MONTHLY CHANGES OF THAT MAGNITUDE ARE NOT UNUSUAL
The new spike gives us a record high sea surface temperature anomaly in the extratropical North Pacific, so it’s unusual in that regard. But the magnitude of the monthly change from June to July is not unusual. Figure 11 presents monthly change in the sea surface temperature anomalies for the extratropical North Pacific, where the data represents the value of the month being plotted minus the value of the previous month.
Figure 11
However, when we look at the satellite era, starting the data in 1980 for example, Figure 12, the sudden spike is unusual.
Figure 12
You’ll note that the change from May to June 2013 was even greater than the change from June to July. So for those interested in the 2-month change, refer to Figure 13. A 2-month warming of that magnitude is more unusual, but they have occurred in the past.
Figure 13
I’m sure, if you were to evaluate changes for periods of different lengths–3 months, 4 months, etc.–you will find a period when the recent change appears unusual, but then you’d have to consider the fact that the data have been infilled in earlier years and that we do not know the true extent of the monthly variations in decades past. And there’s something else you need to consider, which we’ll get to in a few moments.
WHAT CAUSED THE SUDDEN SURGE?
It will probably be a year or so before someone publishes a paper about it, but I suspect the sudden upward spike in extratropical North Pacific sea surface temperatures was caused by a shift in wind patterns, related to a change in sea level pressure. In other words, it’s likely weather related.
For example: The North Pacific Index represents the sea level pressure of the central extratropical North Pacific (30N-65N, 160E-140W). Trenberth and Hurrel created the North Pacific Index (aka NPI) for their 1995 paper Decadal atmosphere-ocean variations in the Pacific. So the interrelationships between sea level pressure, wind patterns and sea surface temperatures have been known for decades. Trenberth and Hurrel (1995) used the North Pacific Index to explain the unusual variability in the sea surface temperatures of the North Pacific.
Continuing our example, the North Pacific Index data at the UCAR website lags by a few months, so I used the ICOADS-base sea level pressure data from those coordinates from the KNMI Climate Explorer. Figure 14 presents the July “North Pacific Index” sea level pressures for Julys starting in 1981. As shown, the last time the sea level pressures in the extratropical North Pacific were that high was in 1999, during the La Niña of 1998-01.
Figure 14
ANIMATIONS
I created 3 animations while I prepared this post and downloaded one from the Unisys website. You may need to click start them. Animation 1 is the most recent animation of sea surface temperature anomalies from Unisys.
Animation 1
Animation 2 presents the July sea surface temperature anomaly maps from 2007 to 2013.
Animation 2
Animation 3 includes the weekly sea surface temperature anomaly maps from the week centered on June 5, 2013 through July 31, 2013.
Animation 3
Animations 2 and 3 are based on maps created at the NOAA NOMADS website.
And Animation 4 is of sea level residuals since the first of the year from the JPL website here. The unusual warming of the extratropical North Pacific does not appear to have impacted the sea level residuals there—yet.
Animation 4
It’s unfortunate that the JPL sea level residual data is not available in a user-friendly format.
WHAT DOES THE SOURCE DATASET SHOW?
Always save the best for last.
ICOADS is the source dataset used by NOAA and the UKMO for their sea surface temperature products. It was updated in 2009. See the ICOADS webpage here.
The ICOADS data for the extratropical North Pacific, Figure 15, confirms the spike in July 2013—BUT—it shows sea surface temperature anomalies there were comparable in July 2004.
Figure 15
And that means, based on the new and improved source data, the July 2013 sea surface temperatures in the extratropical North Pacific were the same as they were in July 2004. See Figure 16.
Figure 16
Before you jump to conclusions, I believe the NOAA ERSST.v3b data is based on the older ICOADS source data. And keep in mind that the Reynolds OI.v2 data is based on satellite data and ICOADS in situ data from ships and buoys, also likely the older version. The only sea surface temperature reconstruction based on the new ICOADS data that I’m aware of is HADSST3.
WHAT DOES THE FUTURE BRING?
Is the sudden surge in the sea surface temperatures of the extratropical North Pacific an indication of an upward shift like the one in the late 1980s? Or is it simply a short-term spike like the one in late 1960s (and in 2004 based on the source data)? We’ll just have to watch and see what happens. And we’ll have to see what the UKMO has to say with their HADSST3 and HADISST datasets, but they lag the NOAA data by a month (HADSST3) or two (HADISST).
DATA SOURCES
The Reynolds OI.v2 data was downloaded from the NOAA NOMADS website. All other data was downloaded from the KNMI Climate Explorer.
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
Addendum question: Is there an alternate data set that you think does this better?
I also think this is mainly weather related. It is the same set-up that has led to very warm weather in Alaska and N. Siberia. Keep in mind that the water in those areas often flows into the N. Pacific which accentuates the warming.
Probably something like the high pressure that caused the Greenland melting last summer. Just over a different spot. With the loopy jet stream these cut off systems will be more prevalent in the years to come.
From Roger Sowell on August 6, 2013 at 5:01 pm:
http://phys.org/news/2013-03-high-cesium-fish-fukushima.html
This is why humans should avoid bottom-dwelling fish, aka trash fish, as they naturally accumulate unwanted contaminants that settle at the bottom.
However, as often happens in the rush to rant, the “facts” weren’t properly checked. That may be “more than 7,000 times the allowable safe limit” for Japan, which consumes lots of seafood and other sea products, thus their government is understandably cautious.
Here in the US, where the average diet has much less seafood, we have the FDA’s Derived Intervention Levels (DIL).
Document: http://www.fda.gov/downloads/NewsEvents/PublicHealthFocus/UCM251056.pdf
Referred to by: http://www.fda.gov/NewsEvents/PublicHealthFocus/ucm247403.htm (Fukushima related info)
For Cs-134 and Cs-137 combined, the DIL is 1200 Bq/kg.
Thus for us in the US, this was only 616 2/3 times the allowable safe limit, not “more than 7,000 times”.
Thus by not applying due diligence in fact checking, Mr. Sowell has been more than 11 times as alarming as could possibly have been warranted.
There appears to be a mixup of posts between threads. Anthony? Moderators?
REPLY: Can’t move comments, sorry, Anthony
KDK:
Thus for us in the US, this was only 616 2/3 times the allowable safe limit, not “more than 7,000 times”.
Thus by not applying due diligence in fact checking, Mr. Sowell has been more than 11 times as alarming as could possibly have been warranted.
===
What disingenuous BS ! Whether a fish is 616 x the FSA limit or 7000 x the japanese limit WTF? IT’S TOXIC. Get real.
Philip Bradley says:
The seasonal anomalies are the give away. The pattern of increased summer anomalies means something has changed since the reference period
===
This is always worth bearing in mind whilst looking at “anomaly” data. During the 80’s and 90’s there was a subdued annual variation. This may well be at least partly due to volcanism. This leads to cooler summers and warmer winters, thus reducing the annual variation.
Beyond that, a one or two month spike is just weather and I doubt it’s worth spending too much time head scratching, unless it lasts for >6 months and starts to look like a new super el Nino or something.
From Greg Goodman on August 7, 2013 at 11:40 pm:
Mr. Goodman, I am saddened to hear about the loss of your sense of humor.
Have you considered offering a reward for its safe return?
Admit it or not, but it is important to correctly reference that “more than 7,000 times” bit. For example, post-Fukushima the allowable amounts in Japan were significantly reduced. So now there can be blaring headlines “TOXIC RADIOACTIVE JAPANESE FISH SOLD IN US” where what is banned for sale in Japan isn’t even a tenth of the maximum allowable US level.
Of course if being off an order of magnitude when presenting alarming news isn’t a problem for you, then what does it matter if we’re told there will be two feet of sea level rise per century, or twenty feet? It’s still bad, lot of suffering involved, etc.
While researching, I saw some no-nukes were proposing the limit be cut all the way down to only 5 Bq/kg. Would you be fine with someone reporting that fish was 148,000 times above a proposed stricter standard, without them mentioning the source of that proposal?
BTW, who’s the FSA?
“Mr. Goodman, I am saddened to hear about the loss of your sense of humor.”
Now of course you say it’s a joke but how is anyone else to know that?
But then you then go on to that is does matter, so you weren’t really joking anyway.,
And, yes being an order of magnitude off would matter except for the minor detail that if, even by US food standards, it was not already TWO AND A HALF ORDERS over the legal limit.
I am saddened to hear about the loss of your sense of honesty.
Have you considered offering a reward for its safe return?
From Greg Goodman on August 8, 2013 at 3:34 am:
If they pay attention to my many previous writings, they should know that sarcasm/satire is my default setting. Even when serious, it’s extremely rare I’m 100% serious, there is humor in there somewhere.
Didn’t you notice “BTW, who’s the FSA?” rhymes? Ah, you probably slipped right over “Thus for us in the US” without missing a beat. Your loss.
solar-terrestrial-climate-101 = http://img94.imageshack.us/img94/3161/zlp.png