Back in June I did a comparison of ENSO (La Nina & El Nino) and temperature anomalies (RSS satellite and HadCRUT). At the time, we were just coming out of a La Nina - since we're now at or just past the peak of an El Nino I figured it was a good time to revisit the topic.
The original thread is here:
http://www.astromart.com/forums/viewpost.asp?forum_post_id=664243
There were lots of (civil - thanks Hugh) comments and we looked at the PDO as well, compared to HadCRUT for a longer view since the satellite temps only go back to 1979, and did some long (50 year) smoothing which showed a multidecadal oscillation. I'm not going to rehash everything discussed there with this post, but if someone wants to look at something, we can go there. I put together something new here - adding an offset to account for the lag between ENSO and temps. Also, rather than inverse the SOI as I did in the last tread, I reversed the order of the Y axis for the SOI (because negative SOI indicates El Nino and warm temps and positive indicates La Nina and cool temps).
From the old thread, here's the 12 month smoothed SOI and detrended RSS temp anomalies with the major volcanic eruptions of Chichon & Pinatubo which depressed temps for a year or so:
http://img199.imageshack.us/img199/715/ensorss.jpg
And the same chart with detrended RSS temp anomalies updated to current conditions - since we've since entered an El Nino, temps have risen since the last chart:
http://img442.imageshack.us/img442/6523/ensorssdtrend12monthavg.jpg
Now for something new. Research has show that there is very good evidence that the ENSO takes about 6 months to influence temps, so what I did here was "shift" the SOI forward by six months. 12 months smoothing helps remove some of the variation, but its too show changes over a few months, so what I did was use 3 month smoothing (originally for no other reason than the SOI has to be over/under plus/minus 0.5 to "officially" be called La Nina/El Nino). The resulting matchup is very interesting:
http://img413.imageshack.us/img413/3008/ensorssdtrend3monthavgo.jpg
So, except for the major volcanic erruptions, there is a very good match up with SOI and temps indicating that ENSO has a very major influence on temp variations.
Note that I said variations and not climate. The reason is that the above charts have detrended the RSS data which took out the rise in temp anomalies to show the match in variation. Using untrended RSS data shows that there is an upward trend in the RSS data that is not related to ENSO
http://img175.imageshack.us/img175/1152/ensorss3monthavgoffset.jpg
Now, you may have noticed something about the 3 month charts - if the temp anomalies do follow ENSO by six months, then they would seem to indicate that temp anomalies still have some catching up to do, so should we expect 6 more months of increasing temp anomalies? With that in mind, the record year for RSS (1998) had an average temp anomaly of 0.551C while 2010 so far has an average of 0.614C. This very thing has many talking that 2010 is likely to be a record year:
NASA: "It is nearly certain that a new record 12-month global temperature will be set in 2010"
http://climateprogress.org/2010/03/19/nasa-giss-james-hansen-global-warming-record-hottest-year/
Yeah, I know that's Climate Progress - I linked to their enthusiasm to throw a bit of cold water on that idea.
Look at it this way - for RSS to set a record in 2010, it has to have an average anomaly over 0.614C. So far it has had 0.640C and 0.588C - to put in perspective what it would take to break the record - it will have to average over 0.538C for the rest of the year. With that in mind, here's the monthly SOI offset by 6 months and RSS anomalies:
http://img260.imageshack.us/img260/8348/ensorssmonthlyoffset.jpg
The problem is that RSS has only been over 0.538C for the last two months and while it seems it may go up over the next few months, the El Nino has shown some indication of recent weakening (it resurged in January & February but is weaking again in March). It seems to me unlikely that the El Nino will last more than a few more months, and the surge in temps in Jan & Feb look to have "overshot" the ENSO influence. Considering that, my take is that unless the El Nino holds up longer than say 3 months, I doubt that RSS will break a record in 2010. I haven't looked at GISS and HadCRUT, but seeing that El Nino gooses the satellite temps more than it does the surface temps, I would guess they won't either (but again I haven't looked at them).
The original thread is here:
http://www.astromart.com/forums/viewpost.asp?forum_post_id=664243
There were lots of (civil - thanks Hugh) comments and we looked at the PDO as well, compared to HadCRUT for a longer view since the satellite temps only go back to 1979, and did some long (50 year) smoothing which showed a multidecadal oscillation. I'm not going to rehash everything discussed there with this post, but if someone wants to look at something, we can go there. I put together something new here - adding an offset to account for the lag between ENSO and temps. Also, rather than inverse the SOI as I did in the last tread, I reversed the order of the Y axis for the SOI (because negative SOI indicates El Nino and warm temps and positive indicates La Nina and cool temps).
From the old thread, here's the 12 month smoothed SOI and detrended RSS temp anomalies with the major volcanic eruptions of Chichon & Pinatubo which depressed temps for a year or so:
http://img199.imageshack.us/img199/715/ensorss.jpg
And the same chart with detrended RSS temp anomalies updated to current conditions - since we've since entered an El Nino, temps have risen since the last chart:
http://img442.imageshack.us/img442/6523/ensorssdtrend12monthavg.jpg
Now for something new. Research has show that there is very good evidence that the ENSO takes about 6 months to influence temps, so what I did here was "shift" the SOI forward by six months. 12 months smoothing helps remove some of the variation, but its too show changes over a few months, so what I did was use 3 month smoothing (originally for no other reason than the SOI has to be over/under plus/minus 0.5 to "officially" be called La Nina/El Nino). The resulting matchup is very interesting:
http://img413.imageshack.us/img413/3008/ensorssdtrend3monthavgo.jpg
So, except for the major volcanic erruptions, there is a very good match up with SOI and temps indicating that ENSO has a very major influence on temp variations.
Note that I said variations and not climate. The reason is that the above charts have detrended the RSS data which took out the rise in temp anomalies to show the match in variation. Using untrended RSS data shows that there is an upward trend in the RSS data that is not related to ENSO
http://img175.imageshack.us/img175/1152/ensorss3monthavgoffset.jpg
Now, you may have noticed something about the 3 month charts - if the temp anomalies do follow ENSO by six months, then they would seem to indicate that temp anomalies still have some catching up to do, so should we expect 6 more months of increasing temp anomalies? With that in mind, the record year for RSS (1998) had an average temp anomaly of 0.551C while 2010 so far has an average of 0.614C. This very thing has many talking that 2010 is likely to be a record year:
NASA: "It is nearly certain that a new record 12-month global temperature will be set in 2010"
http://climateprogress.org/2010/03/19/nasa-giss-james-hansen-global-warming-record-hottest-year/
Yeah, I know that's Climate Progress - I linked to their enthusiasm to throw a bit of cold water on that idea.
Look at it this way - for RSS to set a record in 2010, it has to have an average anomaly over 0.614C. So far it has had 0.640C and 0.588C - to put in perspective what it would take to break the record - it will have to average over 0.538C for the rest of the year. With that in mind, here's the monthly SOI offset by 6 months and RSS anomalies:
http://img260.imageshack.us/img260/8348/ensorssmonthlyoffset.jpg
The problem is that RSS has only been over 0.538C for the last two months and while it seems it may go up over the next few months, the El Nino has shown some indication of recent weakening (it resurged in January & February but is weaking again in March). It seems to me unlikely that the El Nino will last more than a few more months, and the surge in temps in Jan & Feb look to have "overshot" the ENSO influence. Considering that, my take is that unless the El Nino holds up longer than say 3 months, I doubt that RSS will break a record in 2010. I haven't looked at GISS and HadCRUT, but seeing that El Nino gooses the satellite temps more than it does the surface temps, I would guess they won't either (but again I haven't looked at them).
