From ICECAP
AMO, The Key Global Climate Indicator By Matt Vooro
The AMO is an ongoing series of long-duration changes in the sea surface temperature of the North Atlantic Ocean, with cool and warm phases that may last for 20-40 years at a time and a difference of about 1F between extremes. These changes are natural and have been occurring for at least the last 1,000 years. [per NOAA].
The AMO index is calculated at NOAAPSD by using the Kaplan SST data set [5×5], determining the area weighted average over the North Atlantic over 0-70N and then detrending this data. The average AMO index or the Atlantic Multidecadal Oscillation index went negative or cool in January 2009 The average for the first 5 months this year is about [-0.06] . It has been cooling since 2003. In the past, the very cold seasons of North America and especially the East coast happened when the annual average AMO went cool [ as low as -0.405] in the 1970’s.
It seems that this level of cool AMO may be several years off as the AMO cooling rate appears to be still slow. Back in 1964 it took about 8 years before the AMO went to [-0.3] by 1971. Review of other periods for similar rates of decline of the AMO show a spread of about 2-8 years. However the solar activity was much higher during 1964-1972 and things may cool down faster currently with extended solar minimum and anticipated low future solar cycles. If AMO does drop faster, then the cold weather like 1964-1979 may be the norm here much sooner and the East Coast will cool down as well as will the globe. The most sustained number of low AMO levels was during the cold spell of 1902 -1925 and again the 1970’s.
The graph below shows how closely Annual Global Air Temperature Anomalies [Crutem3] follow the Atlantic Multidecadal Oscillation Index [AMO] below.
The last interval change was 1994 or about 15 years ago and according to Enfeld et.al (2005), the probability that AMO will switch to cool in 15 years is about 80%. Based on this analysis , there is a high probability that the current cooling phase of AMO which started in 2009 is real and likely sustainable for the next 20 years at least.
The graph below shows the decline of the AMO index from warm to cool between 2005 and 2009 below.
EL NINO 2009-2010
There has been an El Nino within about 12 months after each of the last four solar minimums. The same pattern seems to be developing again now. The El Nino may be a moderate or weak and short lived [about a year]. It may have a minor effect on global temperatures, like in the period 1965-1966 when US temperatures continued to drop despite the El Nino.
AMO appears to be like a thermostat or predictor of global temperatures. ENSO events if moderate or strong seem to modify, amplify or over-ride the AMO effects. This pattern will continue to bring cool yearly temperatures and colder and snowy winters like 2008 and 2009. My best guess is that the climate of the 1960’and 1970’s will be our climate for the next several decades [2-3] at least, and inter-dispersed with periodic warm years. PDO and AMO readings are of limited value for short term use but quite useful and accurate for decadal forecasts. Currently 2009 looks something like 1971 [cool PDO, low cool/ near neutral AMO] and the rest of this decade looks like the 1970’s if you had pick one decade from the past. The 1960’s and the 1950 are also close behind.
This latest period of cooler weather is not the start of some modern ice age or new grand cold minimum but just another cool cycle of the planet that happens about after every 20-30 years more recently when AMO and PDO are both in the cool mode simultaneously. The coldest last such cycle 1902-1925 when AMO hit a single month low of -0.563 and PDO went down to -1.72 and global air temperature anomalies plummeted to -0.581C [crutem3] in 1911. Other such cool periods occurred 1964-1976 and also much earlier during the Dalton and Maunder Minimums. Read more here.
Leif suggested to me that I read a couple of books on the Sun. I did. It was very enlightening, let alone extremely interesting. I challenge anyone here on this blog who continues to believe that the Sun is the MAJOR driver of Earth’s temperature VARIATIONS to read any book about the Sun available at any bookstore, and then continue to state that there must be some unseen/unknown solar driver that hasn’t been discovered yet (but people here who haven’t written a book about the Sun are sure they have the inside scoop on).
Read a book. The Sun is not a good argument against AGW. It is worse than a poor one.
Leif Svalgaard ( 07:15:51)
Then provide a list of forecasts: when made, where published, skill score [include forecasts that didn’t pan out; if I forecast rain every day and include in the list only days where it did rain (my forecast was correct) I would have a perfect score].
And if we asked you to do this for your past sunspot Cycle forecasts you would have to stay silent, right ? Now I mentioned two years ago so do the math. How many winters have we had ? So how many forecasts do you think I could have made ?
So it’s small base but I showed promise in field that is highly lacking. When it comes to predictability from way out. Because you have to learn how to crawl before you can walk.
Here’s a link to this past winter’s discussion and some MET’s joined in while we watched everything unfold. My February call last winter was “exactly” right, to the day. Which was made more than a month out. I originally had also made a December call the year before but I canceled it about a week out. If you want that link just ask and you shall receive.
http://www.easternuswx.com/bb/index.php?showtopic=182573
Pamela Gray ( 07:36:46)
Leif suggested to me that I read a couple of books on the Sun. I did. It was very enlightening, let alone extremely interesting. I challenge anyone here on this blog who continues to believe that the Sun is the MAJOR driver of Earth’s temperature VARIATIONS to read any book about the Sun available at any bookstore, and then continue to state that there must be some unseen/unknown solar driver that hasn’t been discovered yet (but people here who haven’t written a book about the Sun are sure they have the inside scoop on).
Read a book. The Sun is not a good argument against AGW. It is worse than a poor one.
Pamela,
Many long range professional forecasters both post and lurk at easternwx.com and one common theme has been portrayed by many of them before. But it held more weight about a year or so ago when people were willing to talk more openly about their own research and possible relationships. “You would learn more by reading and hanging around eastern then you would in any book or research journal”.
But this also doesn’t mean that you couldn’t have been mislead about things. OTOH let’s not act like what you read in books or journals is the final conclusion, much like a pharohs demand. “Let it be said let it be written.” Because it isn’t.
I found the following article instructive on modeling. When forecasting ENSO, the forecasters are measuring a dynamical model of ENSO (mechanized and mathematically calculated using super computer strength against the standard statistical model (based on historical conditions prior to a forecasted event). The dynamical model takes into account the affects of the variable but calculable (they think) atmosphere (down to the calculable affects of butterfly wings) as well as sea temperature movements. The potential is that this model can take unique circumstances and calculate the event that will happen. The statistical model assumes that there is nothing new under the Sun and what has happened before an event can be used to predict what will happen again without having to calculate it up the ying yang. This seems a good example of what AGW models are trying to do. Maybe they should go back to statistical models.
http://iri.columbia.edu/climate/ENSO/background/prediction.html
The reason why I post this now is that ENSO models are in disagreement about the forecasted Pacific El Nino. The dynamical models are predicting a hot one. The statistical models not so much and some not at all. I wonder what they have in their dynamical models that are predicting “hot and getting hotter” that the statistical models do not have? Hmmmm??????? I sure would like to get my hands on the code for the dynamical model.
Pamela GRAY
Pages 2 and 12 of the attached reference well illustrate how the period 1950-1960 had the most active solar activity in modern times but the global temperatures went down and the pdo went cool. One would expect the opposite if the sun had an immediate effect. I dont think we understand the sun /climate relationship completely yet.
http://www.appinsys.com/globalwarming/PDO_AMO.htm
matt v. great link. And Jim: Okey dokey.
It also demonstrates that a fairly fast oscillating event has a very good chance of “just happening” to occur near the moment of a slower oscillating event with no mechanism involved.