Science a GoGo's Home Page Forums General Discussion Climate Change Forum PDO Has Flipped!!

Larger Pacific Climate Event Helps Current La Nina Linger

Sounds like the PDO has finally become "unstuck". California tender fruit may become a rare commodity.



http://www.jpl.nasa.gov/news/news.cfm?release=2008-066

Hmmm. My thought on this is that California had been producing tender fruit for much longer than the twenty plus years since the 1980s, so I don't think a La Niña or El Niño will have that kind of effect, but I wonder if this La Niña will have a positive effect on the water problems they're having in the western part of the United States.

G'day all,

La Ninas have not been well studied. Their more noisy brother has grabbed all the glory, so to speak. But La Ninas have an effect that lingers longer than an El Nino. So we get a huge spike in 1998 because of a large El Nino but it did not even last the year out. The effects of a La Nina last a while longer.

As to fixing water problems in Western US, I wouldn't count on it. La Nina's "on average" cause a drier Western US than when neutral or an El Nino. They cause much mere Tornados. They cause a great deal more wildfires. They cause drought. All in Western US and to a lesser extent into Mexico. But even in the middle of either a La Nina or an El Nino there are sometimes localised weather systems that go against the averages dramatically. Thus, you could get huge rainfalls in the Western USA right in the middle of a La Nina if the right weather systems get caught up in the Rockies and are affected by other weather systems.

This is what confuses people about cycles of El Ninos, neutral Pacific, and La Ninas. Firstly they are not all that well studied and the studies do not go back all that long. When something is said to have a cycle of five to twenty years then you know that they really do not know the average at all. The cycle actually appears to be around eight years but there just has not been enough of them studied to really work this out.

If you extrapolate farming in Western New South Wales in Australia as a means of determining whether there is an El Nino in place or not because the records of farming go back a hundred years or so, you do tend to find that El Ninos were less common at the beginning of the 20th century and cycled up in the later part of the 20th Century. But this really is guessing more than science, even if it is all that we have.

To determine the Pacific Oscilation you need to know sea temperatures off Chile, off Australia and in the mid Pacific. Or have a satellite that can watch the movement of warm water backwards and forwards around the Pacific.

The one positive thing about global warming is that the Pacific Ocean's circulation, which seems to be a major engine that determines the general climate of very large parts of Asia, the Pacific and half of the US etc, is now being studied. Whether dams are needed in Australia or the US or whether the Monsoon is likely to be late or very heavy is actually something of great use to a great many people.

The interesting thing about all of this is the influence of the El Ninos that dominated the last several years has tended to make the world look like it is warming dramatically. It has created record temperatures in parts of India, severe droughts in Eastern Australia, monsoons that behaved eratically. All of these have been used as "symptoms" of man made global warming when the actual forces seem to be entirely natural cycles that we barely are beginning to understand. The next several years should be influenced by Al Ninas unless a switch occurs, which is always possible. If this is so, firstly there will be massive fires and more tornados, always a good thing to argue that global warming is out of control. But there is also going to be much colder periods and the likelihood of a record hot year recedes dramatically. At that point do the people that have been using the record highs, the tornado counts etc, and hurricanes as "proof" of global warming, suddenly apologise and say, hey it looks like it is cooling after all! I think not.


Richard

Thanks Richard,
...end of semester, busy week; I promised myself I wouldn't do this, but:
Taking a break, I ran across this:

http://hypography.com/news/environment/35505.html
N. Pacific Gyre Oscillation/ NPGO
...and then more....
google: Di Lorenzo NPGO
for a two page list of quality links.
i.e.
http://www.o3d.org/npgo/
&

http://eros.eas.gatech.edu/npgo/videos-images.html
===
Videos of presentations
North Pacific Gyre Oscillation: links ocean climate and ecosystem change - [ 10 min. talk ]
North Pacific Gyre Oscillation: the forcing and the oceanic response- [ 13 min. talk ]
North Pacific Gyre Oscillation: linking decadal variations in the extratropics and tropics - [ 10 min. talk ]
Coherent decadal variations in Northeast Pacific and Kuroshio-Oyashio Extension - [ 10 min. talk ]
Decadal variations in the California Current upwelling cells - [ 1 min. animation ]

Slides and Images - [ Download a singe PDF file ]
Pacific Decadal Oscillation (PDO) vs. North Pacific Gyre Oscillation (NPGO) - [ pdo_npgo.png ]
Coherent variations of nutrient and salinity in the Northeast Pacific - [ npgo_S.png | npgo_N.png ]
Comparison between Victoria Mode and NPGO - [ npgo_victoria.png ]
NPGO and PDO modulate decadal variations in upwelling along the eastern boundary - [ pdo_npgo_upw.png ]
An inverse approach to study decadal variations in upwelling - [upw_adjoint.png ]
ROMS model hindcast 1950-2004 of California Current observations - [npgo_roms_calcofi.png ]
Large-scale patterns of NPGO in SSH and SST - [ npgo_SST_SSH.png ]
Linking NPGO to large-scale ecosystem variability in the Pacific - [ npgo_ecosys.png ]
NPGO linked to decadal variations in the Kuroshio-Oyashio Extension (KOE) - [ npgo_koe.png ]
A quasi-decadal deterministic cycle of the Pacific Ocean?
===
I hope to be able to enjoy several hours this weekend with the above.

I'll try to check these videos out when I get home and thanks Richard.

Hardly documentation from a scientific journal, but interesting post on the BBC news website, also related to 'increased understanding' of how ocean current cycles may have significant impact on climate models ......

http://news.bbc.co.uk/2/hi/science/nature/7376301.stm

I particularly like the quote from this article :

The projection does not come as a surprise to climate scientists, though it may to a public that has perhaps become used to the idea that the rapid temperature rises seen through the 1990s are a permanent phenomenon.

"We've always known that the climate varies naturally from year to year and decade to decade," said Richard Wood from the UK's Hadley Centre, who reviewed the new research for Nature.

"We expect man-made global warming to be superimposed on those natural variations; and this kind of research is important to make sure we don't get distracted from the longer term changes that will happen in the climate (as a result of greenhouse gas emissions)."

A bit of a dilemna for these guys ... its either ...
"we were expecting this cooling period .... but ....er ...forgot to mention it" ......
.... or ....."don't worry that we got it wrong in the short term because our long term temperature rise models are still going to be bang-on".

Hello ImranCan

I posted a link on the global warming thread, but I will put it here also. This article came from the BBC but I don't think it is the same article you are talking about.

http://www.unexplained-mysteries.com/viewnews.php?id=125125

best regards,
odin1

ImranCan - you're absolutely right, it is quite the dilemma for these guys.
We're hearing more and more "scientists" go on about these natural cycles now "masking" anthropogenic warming. I'm waiting for somebody to ask them why can these natural cycles only seem to mask the cycles. Haven't we been told over and over that the natural variation (which we understand soooo well) simply aren't strong enough to do what we've seen?


On another note.........We're now 4 consecutive months with the global average temperature being right at the long term average.
http://www.remss.com/pub/msu/monthly_tim...Ocean_v03_1.txt