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NASA reports hottest June to September on record*; NOAA says “weak” El Niño “expected to strengthen and last through” winter

October 13, 2009

Fast on the heels of the second warmest August on record and warmest June-July-August for the oceans, NASA’s Goddard Institute for Space Studies reports that this was the second hottest September on record.

Unlike NOAA, which will announce its September global analysis in a few days, NASA just quietly updates its data set (here).  So you have to do a little math to see that for the June through September period, 2009 now tops both 2005 and 1998.  I put the asterisk in the headline since these four months in 2009 are only slightly warmer than those in 1998.

I’m not cherry-picking these last four months, but rather ENSO-picking them.  The reason 1998 was so anomalously warm even beyond the human-caused trend was the uber-El Niño.  Back in January, NASA had predicted:  “Given our expectation of the next El Niño beginning in 2009 or 2010, it still seems likely that a new global temperature record will be set within the next 1-2 years, despite the moderate negative effect of the reduced solar irradiance.”

Then, back in early June NOAA put out “El Niño Watch,” which I noted meant that “record temperatures are coming and this will be the hottest decade on record.”  So here we are.

What makes these record temps especially impressive is that we’re at “the deepest solar minimum in nearly a century,” according to NASA.  It’s just hard to stop the march of anthropogenic global warming, well, other than by reducing GHG emissions, that is.

Another thing that makes these record temps impressive is that we’re only in a “weak El Niño,” according to the latest monthly “El Niño/Southern oscillation (ENSO) Diagnostic Discussion” of the Climate Prediction Center of NOAA’s National Weather Service:

Synopsis: El Niño is expected to strengthen and last through the Northern Hemisphere winter 2009-2010.

A weak El Niño continued during September 2009, as sea surface temperature (SST) anomalies remained nearly unchanged across much of the equatorial Pacific Ocean (Figs. 1 & 2). Since the transition to El Niño conditions during June, the weekly values of the Niño-3.4 index have remained between +0.7°C and +0.9°C (Fig. 2). Subsurface oceanic heat content (average temperatures in the upper 300m of the ocean, Fig. 3) anomalies continued to reflect a deep layer of anomalous warmth between the ocean surface and the thermocline, particularly in the central and east-central Pacific (Fig. 4)….  These oceanic and atmospheric anomalies reflect an ongoing weak El Niño.

A majority of the model forecasts for the Niño-3.4 SST index (Fig. 6) suggest that El Niño will reach at least moderate strength during the Northern Hemisphere fall (3-month Niño-3.4 SST index of +1.0°C or greater). Many model forecasts even suggest a strong El Niño (3-month Niño-3.4 SST index in excess of +1.5°C) during the fall and winter, but in recent months some models, including the NCEP CFS, have over-predicted the degree of warming observed so far in the Niño-3.4 region (Fig. 7). Based on the model forecasts, the seasonality of El Niño, and the continuation of westerly wind bursts, El Niño is expected to strengthen and most likely peak at moderate strength.

ENSO 9-09

What is particularly interesting to me is the prediction that, while his is not going to be a blockbuster El Niño in terms of amplitude, as we saw in 1997-1998, it may turn out to be a pretty long one.  If it lasts through June 2010, then that year seems poised to be the hottest on record.

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6 Responses to “NASA reports hottest June to September on record*; NOAA says “weak” El Niño “expected to strengthen and last through” winter”

  1. Richard Brenne says:

    Great work as always, Joe. It’s good for all of us to be ready for “the fire next time” to help the public and policy makers better understand how real climate change is and how the narrow window of opportunity to appropriately address it is rapidly shutting.

    What are the best estimates for when the current solar minimum will cycle toward the next maximum? That combined with a moderate to strong El Nino superimposed over human-caused warming should get our attention, or nothing within the next decade will.

  2. Mike D says:

    Richard: The normal Schwabe cycle of solar activity is 11 years, with less than 2 years at solar minimum. The previous solar minimum was in 1996 so the next one was expected in 2007, but it started early in 2006 and has lasted into this year, much longer than usual. But apparently it’s cycling up again now, with the next solar maximum in 2013 or so, a little later than usual, although it is projected to be the weakest in about a century.

  3. Richard Brenne says:

    Thanks Mike D, excellent answer. I knew about the Schwabe cycle but was confused about the anamolies – was this minimum the weakest in about a century also?

    And are you a scientist or a good popularizer (or both)?

  4. Mike D says:

    Yes it was the weakest since 1913 or something like that. It was actually so long and deep that some thought we had entered a new phase like the Maunder or Dalton Minimums where the activity fell off for decades (and the earth got colder). Guess not though.

    I’m not a scientist but I am an educator so glad to hear I am getting the message across!

  5. Mike D says:

    Also interesting to note that neither of the two hottest years (1998 & 2005) were at a period of solar maximum. The last max was just after the turn of the century so in 1998 it was cycling up and in 2005 it was cycling down.