Second warmest March on record; will La Niña be gone by hurricane season?
March 2008 was the 2nd warmest March for the the globe on record, according to statistics released by the National Climatic Data Center. Over the Northern Hemisphere, and over all of the globe's land areas, March 2008 was the warmest March in the 128-year global record. Only the presence of a moderately strong La Niña event that cooled ocean waters in the central and eastern equatorial Pacific prevented March 2008 from surpassing March 2002 as the warmest March on record. March broke a string of three straight months when the globe did not record a top ten warmest month ever. Between February 2006 and November 2007, the globe set top ten monthly warm temperature records for 22 straight months.
Figure 1. Departure of temperature from average (the anomaly) for March of 2008, the second warmest March on record for the globe. While the U.S. recorded slightly below average temperatures, much of Asia and Europe saw remarkably warm temperatures. Image credit: National Climatic Data Center.
How much cooling did La Niña give to the globe in March?
La Niña is a periodic cooling of the Equatorial waters of the Eastern Pacific that occurs every 3-7 years. The cooling is due to a natural cycle of anomalous winds from the east that act to push surface waters away from the coast of South America, allowing cold water from deep in the ocean to rise to the surface to replace the surface waters blown to the west. These cool waters often cause a noticeable drop in global temperatures. Conversely, when the opposite phenomena occurs--an El Niño event, which brings anomalously warm Sea Surface Temperatures (SSTs) to the Equatorial Eastern Pacific, enough heat is added to the atmosphere that global temperatures warm significantly. According to Trenberth et al. (2002), a typical El Niño event increases global temperatures by about 0.1°C. Exceptional El Niño events, such as occurred in 1997-1998 and 1982-1983, increase global temperatures by up to 0.2°C. El Niño events heat the atmosphere by causing changes in cloudiness and atmospheric circulation, and through direct radiation of heat from the ocean to the atmosphere. There is a lag of 3-6 months between the time an El Niño event occurs and the time the atmosphere heats in response. Similarly, when a La Niña event occurs, heat is drawn out of the atmosphere and the oceans are recharged with heat. Global temperatures cool, again with a lag of 3-6 months. The correlation between global temperature anomalies and El Niño/La Niña temperature anomalies can be plainly seen in Figure 2. Note that the correlation is not perfect--there are some El Niño/La Niña events that do not affect the global temperature much. For example, global temperatures did not cool much during the strong 1988-1989 La Niña event. Therefore, it is a good bet--but not certain one--that had we not had a strong La Niña event this winter, March 2008 would have been the warmest March on record, since it missed the record by only 0.04°C.
Figure 2. Comparison of temperature anomalies in the equatorial Pacific Ocean bounded by a box between 5°S, 5°N, 120°W, and 180°W (the Niño 3.4 region) and global temperatures for 1950-1998. Means for 1950-1976 and 1977-1998 (horizontal lines) are shown separately to highlight a climate shift that occurred in 1976/1977. The reasons for this shift are unknown. Note that when an El Niño event occurs, the globe tends to warm by about 0.1°C, and when a La Niña event occurs, the globe tends to cool. Image credit: American Geophysical Union's Journal of Geophysical Research.
Warmest month ever stats
It is interesting to compare what the phase of El Niño/La Niña was during each of the 12 record warmest months the globe has recorded. If we adjust for the 3-6 month lag between an El Niño/La Niña event and the monthly global temperature records, it turns out that nine of the twelve monthly records were set when an El Niño event occurred during the 3-6 month period prior to the record. Considering that climatologically El Niño conditions are present only about 25% of the time, El Niño has a major impact on when record global warmth will occur. The warmest year on record, 1998, occurred during the strongest El Niño of the past century. The table below compares the 12 monthly global temperature records with the temperature in the Niño 3.4 region (a 3-month average centered four months before the record was set). El Niño events, which occur when the Niño 3.4 index is greater than 0.4°C, are marked with an "E".
Record......Niño 3.4 index
-----------------------------
Jan 2007 +0.7 E
Feb 1998 +1.7 E
Mar 2002 -0.1
Apr 1998 +2.5 E
May 1998 +2.3 E
Jun 2005 +0.5 E
Jul 1998 +1.4 E
Aug 1998 +1.1 E
Sep 2005 +0.5 E
Oct 2003 +0.0
Nov 2004 +0.7 E
Dec 2003 +0.4
Figure 3. A La Niña event exists when ocean surface temperatures in the equatorial Pacific Ocean bounded by a box between 5°S, 5°N, 120°W, and 180°W (the Niño 3.4 region) are cooler than 0.4°C below average (based on means from 1971-2000). La Niña events between 0.5°C and 0.9°C are referred to as weak, 1.0°C and 1.4°C are moderate, and 1.5°C or cooler, strong. The winter of 2007-2008 saw strong La Niña conditions, but this has weakened to a moderate event in March. Image credit: NOAA Climate Prediction Center.
An El Niño by hurricane season?
Presence of El Niño conditions usually causes enhanced levels of wind shear over the Atlantic, reducing hurricane activity, so it would be nice to see an El Niño this Fall. The strong La Niña event we had over the past winter has weakened considerably in the past two months, and is now classified as a moderate event, according to the latest El Niño discussion issued by NOAA's Climate Prediction Center. There is some hope that an El Niño will develop by hurricane season. Two of the long-range computer models are now calling for an El Niño to develop by hurricane season (Figure 4), and none of them were calling for El Niño last month. However, there is probably not time for a full-fledged El Niño event to develop, and it is expected that we will have weak La Niña or neutral conditions this hurricane season. Since reliable El Niño records began in 1950, there has never been a switch over to El Niño by hurricane season from a La Niña as strong as the one we have now. Columbia University's International Research Institute is predicting that neutral El Niño conditions are most likely for the coming hurricane season (57% chance), with a 20% chance of an El Niño, and 23% chance of a La Niña. This is pretty much what climatology says--on average, we experience El Niño conditions 25% of the time and La Niña conditions 25% of the time.
Figure 4. Computer model forecasts of El Niño/La Niña made in April. The forecasts that go above the red line at +0.5°C denote El Niño conditions; -0.5°C to +0.5°C denote neutral conditions, and below -0.5°C denote La Niña conditions. Image credit: Columbia University's IRI.
References
Trenberth, K. E., J. M. Caron, D. P. Stepaniak, and S. Worley, >Evolution of El Niño, Southern Oscillation and global atmospheric surface temperatures", J. Geophys. Res., 107(D8), 4065, doi:10.1029/2000JD000298, 2002.
I'll be in Orlando next week for the American Meteorological Society's bi-annual hurricane conference, and plan to make some quick posts during the week to update everyone on the latest hurricane research. I may make one more post before then.
Jeff Masters
Reader Comments
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Hey Ike; nice to see you around, hope all is well with you (with the exception of gas prices and the heat)...I've been around the Big Bend from Tallahassee to Bonifay over the past few days (in Marianna Florida right now) and the heat is really kicking....Although, there is some rain coming (as you know) and it's been pretty cloudy and a little drizzly in some parts (it was drizzing in Chipley when I was there an hour ago)..........
398. IKE 8:14 PM GMT on April 25, 2008
Or sooner, if a cat 3 makes it into the GOM this summer/fall.....
I don't think anyone wants to know how much prices would get in that case lol
They would get really high... If more than one major hurricane moved through
400. extreme236 8:16 PM GMT on April 25, 2008
398. IKE 8:14 PM GMT on April 25, 2008
Or sooner, if a cat 3 makes it into the GOM this summer/fall.....
I don't think anyone wants to know how much prices would get in that case lol
They would get really high... If more than one major hurricane moved through
-- Yeah, LOL; they are "high" now! But, they could and likely to get much higher!
401. weathermanwannabe 3:20 PM CDT on April 25, 2008
396. IKE 2:11 PM CST on April 25, 2008
Hey Ike; nice to see you around, hope all is well with you (with the exception of gas prices and the heat)...I've been around the Big Bend from Tallahassee to Bonifay over the past few days (in Marianna Florida right now) and the heat is really kicking....Although, there is some rain coming (as you know) and it's been pretty cloudy and a little drizzly in some parts (it was drizzing in Chipley when I was there an hour ago)..........
It's suppose to briefly cool down the beginning of next week, but warm right back up into the mid 80's by the end of next week.
And, since the variability of the MJO is partly linked to the ENSO cycle, conditions present themselves as another possible factor for storms developing this season. Strong MJO activity is often observed during weak La Nina years or during ENSO-neutral years, while weak or absent MJO activity is typically associated with strong El Nino episodes.
There is evidence that the MJO modulates this activity (particularly for the strongest storms) by providing a large-scale environment that is favorable (unfavorable) for development. The strongest tropical cyclones tend to develop when the MJO favors enhanced precipitation. As the MJO progresses eastward, the favored region for tropical cyclone activity also shifts eastward from the western Pacific to the eastern Pacific and finally to the Atlantic basin.
Currently, the MJO is weak and over the Maritime Continent propagating eastwards. By the time it arrives in our hemisphere, hurricane season will be upon us. I haven't looked extremely close, but am guessing that the timing looks accurate to that effect. According to what I've read, a strong MJO is more likely during La Nina or neutral conditions which is what we've sort of concluded. That being the case, add a strong MJO pulse to the tATL along with the many other variables that seem to be coming into place, then evidence becomes more clear of our potential for having a serious tropical season.
(Some of this info is from NOAA's CPC)
weathermanwannabe are you hindu's, or muslims?
Actually, I'm (in my current incarnation) a well respected trial attorney in North Florida; what you you mean by that remark?...........
...The results change from the daily run, but right now it shows the A/B high (surface) averaging 1026 mb for July, 1022 mb for August, and 1020 mb for September. It has the high centered (fluctuating) from just west of the Azores, to over the Azores.
- StormW, doesn't that seem to indicate "fish" - especially if the high is not that strong as that model suggests? TIA
And it really only takes one to devastate a city. Thats what happened in 1992.
411. moonlightcowboy 5:27 PM EDT on April 25, 2008
406. StormW 3:27 PM CDT on April 25, 2008
...The results change from the daily run, but right now it shows the A/B high (surface) averaging 1026 mb for July, 1022 mb for August, and 1020 mb for September. It has the high centered (fluctuating) from just west of the Azores, to over the Azores.
- StormW, doesn't that seem to indicate "fish" - especially if the high is not that strong as that model suggests? TIA
It would seem that way...but again, the model is putting out the "mean" for each month and that's over 3 months in advance. One thing I did notice is, it seems just a tad farther south in it's mean postioning, and it's so large that the 1016 and 1014 isobars extend into the Caribbean and in the Atlantic (just south of 15N). We'll have to see...as if we have a negative NAO, it would indicate a steering pattern of allowing storms to come further west (i.e. Florida and East Coast hits)
Yes the key is the "mean".
Mean SLP for March.
850mb wind mean
Nice visual aid, Drakoen, thanks!
No problem. I had been meaning to get around to posting that image especially since you asked about something like this before.
re post #408 - from Moonlightcowboy: "Some of this info is from NOAA's CPC"
A bit of an understatement from MLC. Actually, most of his post, and most of his current blog, is lifted verbatim from from other sources. See here, for example. I'm not sure where some people get the idea that plagiarism is an acceptable practice; I was always taught, and still firmly believe that presenting another's words or ideas as one's own is dishonest, plain and simple.
Your post is not necessary and he sourced the information which is allowed on Wunderground.
The MJO subject was fascinating, but good "digestible" info was scattered about over NOAA's CPC's site, etc. My blog and my post, put together some pieces of that information, so that, hopefully, I and a few others could possibly understand more about the MJO.
I think you'll also find that I noted (despite) that some of the info did come from that site.
Congratulations! You've just been added to the ban and ignore list, too!
424. Drakoen 4:45 PM CDT on April 25, 2008
850mb wind mean
I noticed that you show the means, but aren't the anomalies more important? This shows stronger than average trades over most of the Atlantic:
It was to show the surface position of the high and wind flow. I'm not talking about tradewinds...
No worries, Drakoen! He and I ran into each other a while back on Ricky's blog. He's just being divisive. LOL, "like water off a duck's back" - wait, who said that? Should I quote that? Prick!
LOL...
I agree it's good to cite sources. I also agree that some formal format for doing so is not required on a blog like this. I also didn't find it difficult to tell the difference between what MLC wrote himself and what he cut/paste from the CPC site.
I can see we will have to be "encouraging" some of the newcomers and occasional posters to understand the difference between request and demand . ..
I'm also noting the comments on the AB high forecast with interest and, dare I say, dread? That graphic Drak posted suggests that the shape of the high will act like a "fast track" through the Bahamas.
just say that I said it.
LOL
oh for crying out loud.
just say that I said it.
LOL
No I said it LOL...
If I'm quoting something on my own blog, though, I'd make sure I'm referencing. I think the doc provides a good model of how it should be done.
I think it's about time I made another huge dinner
You, Drak, Baha, etc for everyone
Wait, I might need a bigger garden to pull that off!
ROTFL
"This is being blown way out of proportion for no good reason..."
Maybe in your opinion but I'm a big fan of intellectual honesty. MLC has a long history of ripping off other's words without attribution and I think that he's likely to keep at it unless someone calls him on it. The small details are important, like it or not.
Believe it or not, tone is everything. Implying someone is dishonest based on your word choice("ripping off others' words", "calls him on it")is the way to get a new rear end ripped in here. It also will get you ignored, minused, and banned, because it comes across as an ad hominem attack designed to create strife rather than genuinely inform the blog.
It's possible to ask someone to cite sources without getting nasty. If you can't confront others in here in a respectful and respectable way, you bring the "nastiness" on yourself.
PS. Read the Admin Notice:
When using Dr. Masters' blog, please refrain from posting material not relevant to the discussion of tropical weather, or the topic of the blog entry itself. Please do not engage in personal attacks or bickering. Material not conforming to these standards should be flagged with the button and ignored.
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