Watts Up With That?

For now, we have about 1 year of significant cold phase tendency in the Pacific Decadal Oscillation (PDO), here is the last 108 years of the PDO index, plotted from monthly values:

Click for larger image – source Steven Hare, University of Washington

Compared to the negative magnitudes seen from 1946 to 1977, our current PDO phase shift magnitude is relatively mild. But that could change. Don J. Easterbrook, a retired professor from the Dept. of Geology, Western Washington University, in Bellingham, WA sends this analysis:

la-nina-and-pacific-decadal-oscillation-cool-the-pacific (PDF)

The announcement by NASA’s Jet Propulsion Laboratory that the Pacific Decadal Oscillation (PDO) had shifted to its cool phase (Fig. 1) is right on schedule as predicted by past climate and PDO changes.

Global temperatures peaked in 1998 and have not been exceeded since then. Pacific Ocean temperatures began a cooling phase in 1999 that was briefly interrupted by El Nino and dramatic cooling in 2007-2008 appears to be a continuation of a global cooling trend set up by the PDO cool phase (Fig. 1) as predicted [shown in the figure below].

Thus, we seem to be headed toward several decades of global cooling, rather than the catastrophic global warming predicted by IPCC.

If we are lucky, this PDO will be a short event. 2-4 years. If we are unlucky, and it is the “full Monty” phase switch at 20-30 years as Easterbrook suggests, we may be in for extended cooler times. This may result in some significant extended worldwide effects, notably on agriculture.

UPDATE! Professor Easterbrook adds in comments:

“The projected warming from ~2040 to ~2070 is NOT driven by CO2, it’s merely a continuation of warm/cool cycles over the past 500 years, long before man-made CO2 could have been a factor. We’ve been warming up from the Little Ice Age at rate of about 1 degree or so per century and the 2040-70 projection is simply a continuation of non-AGW cycles.

An interesting question is the similarity between what we are seeing now with sun spots and global temperature and the drop into the Little Ice Age from the Medieval Warm Period. Could we be about to repeat that? Only time will tell–We might see a more pronounced cool period like the 1880 to 1910 cool cycle (when many temp records were set) or a milder cooling like the 1945-1977 cool cycle. In any case, the setting up of the cool phase of the PDO seems to suggest cooler times ahead, not the catastrophic warming predicted by IPCC and Al Gore.”

La Nina and Pacific Decadal Oscillation Cool the Pacific

Click here to view full image (228 kb)

 ”The shift in the PDO can have significant implications for global climate, affecting Pacific and Atlantic hurricane activity, droughts and flooding around the Pacific basin, the productivity of marine ecosystems, and global land temperature patterns. ” – NASA JPL

       
A cool-water anomaly known as La Niña occupied the tropical Pacific Ocean throughout 2007 and early 2008. In April 2008, scientists at NASA’s Jet Propulsion Laboratory announced that while the La Niña was weakening, the Pacific Decadal Oscillation—a larger-scale, slower-cycling ocean pattern—had shifted to its cool phase.

This image shows the sea surface temperature anomaly in the Pacific Ocean from April 14–21, 2008. The anomaly compares the recent temperatures measured by the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) on NASA’s Aqua satellite with an average of data collected by the NOAA Pathfinder satellites from 1985–1997. Places where the Pacific was cooler than normal are blue, places where temperatures were average are white, and places where the ocean was warmer than normal are red.

The cool water anomaly in the center of the image shows the lingering effect of the year-old La Niña. However, the much broader area of cooler-than-average water off the coast of North America from Alaska (top center) to the equator is a classic feature of the cool phase of the Pacific Decadal Oscillation (PDO). The cool waters wrap in a horseshoe shape around a core of warmer-than-average water. (In the warm phase, the pattern is reversed).

See the entire story here:
http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=18012

See the PRESS RELEASE from JPL here:
http://www.jpl.nasa.gov/news/news.cfm?release=2008-066

Look out California agriculture. The wine industry, fruits and nut growers will be hit with a shorter growing season and more threats of frost, among other things.

Recently in Nevada County, much of their grape crop was wiped out. From The Union in Nevada County (h/t Russ Steele)

Nevada County’s agricultural commissioner will seek disaster relief from the state after tens of thousands of dollars worth of crops were ruined from last week’s freezing temperatures.

Orchard trees, wine grapes and pastures were hardest hit, Pylman said. The commissioner is compiling a report of damages that he will send to the state Office of Emergency Services in coming weeks.

“Growers don’t have anything to harvest. That’s a disaster in my mind,” Pylman said.

 
In Paradise, CA, Noble Orchards reports damage to their Apple crop from recent colder weather, as well as reports of issue with vineyards in the Paradise ridge area suffering from frost damage recently.

Here is a short history of PDO phase shifts:

In 1905, PDO switched to a warm phase.
In 1946, PDO switched to a cool phase.
In 1977, PDO switched to a warm phase.

California agriculture has ridden a wave of success on that PDO warm phase since 1977, experiencing unprecedented growth. Now that PDO is shifting to a cooler phase, areas that supported crops during the warm phase may no longer be able to do so.