Bump - sort of.
The recent decrease in trade wind strength over the Pacific, which stalled the decay of the current El Niño event, appears to have ended. Trade winds have strengthened over the Pacific during the past fortnight, leading to a slight cooling of the ocean surface temperatures in the central Pacific. In contrast, temperatures in the far eastern Pacific have risen, though this rise is a flow-on effect from a wind burst in January/February, rather than any indicator of a return to warm conditions more generally. Overall, Pacific Ocean temperatures remain at levels associated with an El Niño event, but are again cooling in line with expectations.
The most noticeable feature of the past fortnight has been the decrease in Pacific Ocean heat content, with values east of the dateline dropping to their lowest values since April 2009, indicating the deeper ocean is also slowly cooling. Likewise, sea surface height in the central and eastern Pacific is also decreasing.
Computer models suggest Pacific Ocean temperatures will cool steadily over the coming months, returning to neutral levels by the southern winter.
The Indian Ocean Dipole (IOD) is currently neutral and is forecast to remain so through autumn.
from -
http://www.bom.gov.au/climate/enso/" href="http://www.bom.gov.au/climate/enso/">http://www.bom.gov.au/climate/enso/
Edited by user 08 April 2010 10:10:28(UTC) | Reason: Not specified
see also for present info.-
http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ensoyears.shtmlhttp://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/index.html
http://www.bom.gov.au/climate/enso/
This is the likely outcome but we are still in the spring predictability gap. The forecast state of ENSO after the summer should become clearer in a couple of months time
Acording to his graph the cumulative warming in region 3.4 is more than 10C. Do you think that is right? or is he data manipulating...
It is a cumulative index.
There are longer lasting impacts from an El Nino (which do not consistently appear but occur often enough).
The ocean circulation from the ENSO (and there is literally a surface current that flows across the Pacific from east to west with the prevailing winds) eventually filters off in three directions at about 160E;
- one downward to about 250M depth (to resurface in the eastern Pacific later);
- one filters through Indonesian islands into the Indian ocean; and,
- one filters north to form part of the Kurushio current and eventually impacts the north Pacific and the PDO index.
The heat energy released into the atmosphere from an ENSO lags behind the ocean surface by about 2 months but the additional warmth eventually warms up northern North America and it also warms up the north Atlantic Ocean, first closer to the equator and then the northern latitudes.
Some of the highest AMO index values have occured about 4 to 5 months after the large El Ninos. The AMO spiked up to 0.335 last month, the highest number in 4 years and based on the 0N to 30N SSTs, the spike is not over yet and could go up to 0.600 or so in the next two months which is nearing AMO index record values.
Generally, there is a 3 month lag from the ENSO to global temperatures but there can be (smaller) longer lasting impacts in many areas from a bigger than normal El Nino.
But a La Nina is going to follow this El Nino and it should be apparent in a few months, peaking around Christmas as most ENSO events do.
The big blue blob below (which is technically, the cool water left over from the 2008-09 La Nina) will eventually surface at about 110W and we will have another La Nina.
Edited by user 08 April 2010 14:44:47(UTC) | Reason: Not specified
So you are saying as I think we all agree, that the impacts of ENSO on global temperature are not cumulative. Your prediction of a La-Nina next year is interesting but currently only a minority of models are going for that at present , we should know better in a few months time.
Edited by user 08 April 2010 14:53:47(UTC) | Reason: Not specified
I think you should examine why it is so important to you that everyone agree with you on everything. People should be able to hold different positions on things, especially when the facts are not solidly clear. There are some curious climate step changes associated with big El Ninos.
There have been 4 Super El Ninos that we know about (1862, 1877, 1982, 1997 - probably just a coincidence that they follow the same pattern 120 years apart) and there might be is a slight step change with each one. Then there is the long-lasting El Nino of 1939 to 1941 which lead to a peak in temperatures in the mid-1940s.
Do you have a link to your diagram the resolution is poor on the screen ? Surely also you are saying that the long lasting El-Nino 1939 to 41 was followed by a peak in warmth in the mid 40s I don't see cause and effect.
Edited by user 08 April 2010 16:08:04(UTC) | Reason: Not specified
Still getting used to this new board - the chart looks very good on my screen - it doesn't on yours?
http://img12.imageshack.us/img12/9844/superelninos.png
The cause is the long-lasting El Nino from 1939 to 1941 (which obviously dumped heat energy into the atmosphere) - the effect is the peak temperatures in the mid-1940s which were not surpassed until the early 1990s.
http://hadobs.metoffice.com/hadcrut3/diagnostics/global/nh+sh/monthly.png
I am not convinced by the cause and effect, can you quote a study that attributes this
http://www.pnas.org/content/105/34/12154.full
http://www.giub.unibe.ch/~broenn/agu_1940s.pdf
http://www.nature.com/nature/journal/v431/n7011/pdf/431920a.pdf
http://www.nature.com/nature/journal/v431/n7011/full/nature02982.html
Edited by user 08 April 2010 18:13:58(UTC) | Reason: Not specified
I have read these papers they are fascinating and illustrate the widespread impacts of the extended El-Nino (1939-1942) on regional weather across the globe through stratospheric coupling. As expected this El-Nino acconts for global warming over the period 39-42 but there is no evidence in these papers that this would extend much beyond 42/43. So a very prolonged El-Nino and what a great natural experiment and a lot was learnt by the later analysis.
My final note on the mid-1940s warm period is that CO2 WAS NOT INVOLVED since CO2 levels actually declined between 1940 to 1946.
You got a source?
Please, don't say EG Beck.
Edited by user 09 April 2010 03:40:56(UTC) | Reason: Not specified
This is from the ice cores. The high resolution ones all show flat numbers from 1937 to 1939 and then a slight decline from 1939 to about 1949. [It could be the war years or a response to the warming that occured over the period].
Here's one.
http://cdiac.ornl.gov/ftp/trends/co2/lawdome.combined.dat
You can also see the decline in GHG forcing in this table of forcings used by GISS.
http://www.realclimate.org/data/forcings_obs1880-2003.txt
Thanks Bill, although the GISS one only mentions well mixed GHGs and doesn't separate CO2 forcing. And the law dome figures are smoothed over 20 years. However the figures do suggest a slight decline in the 40s - but I severly doubt it was in response to the warming, for example we observe in the Mauna Loa record that in the cool post-Pinatubo years the rate of CO2 increase slowed, and it increased after the 98 El Nino (perhaps a similar response could have been expected at the start of the 40s?).
One thing is that if the levels of well mixed GHGs had risen and then remained constant/declined slightly for a few years, the temperature would still have been heading towards equilibrium, so a little warming due to GHGs could still be expected over that period. Perhaps aerosol forcing decreased due to the war, simultaneous with a drop in GHG emissions? That would also contribute to some warming.
The sea temperatures are achanging.
http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf
A La Nina now expected? - how big?