This winters' weather - a combination of things
This is an unusual Winter with record cold temperatures and record precipitation levels (both high and low).
I know that I keep harping on "
Sun as climate driver" and I know that we are also experiencing La Ni�a which began in mid-2007. Curiously, we had a small El Ni�o (hot) running from early Fall 2006 through March-April of 2007. This is odd as they are usually spaced a year or two apart.
This
table shows the seawater temperatures since 1950 -- red numbers are El Ni�o, blue numbers are La Ni�a. (Each cell is a running three-month average so the leftmost one is December, January, February or DJF; the next cell is Jan. Feb. Mar. or JFM; etc...)
The generalized effect of La Ni�a in the United States can be found here:
La Ni�a FAQ
Answers to La Ni�a frequently asked questions
What are the U.S. impacts of La Ni�a?
La Ni�a often features drier than normal conditions in the Southwest in late summer through the subsequent winter. Drier than normal conditions also typically occur in the Central Plains in the fall and in the Southeast in the winter. In contrast, the Pacific Northwest is more likely to be wetter than normal in the late fall and early winter with the presence of a well-established La Ni�a. Additionally, on average La Ni�a winters are warmer than normal in the Southeast and colder than normal in the Northwest.
Emphases mine -- OK. Check and Check. But let's look at the first statement:
Pacific Northwest is more likely to be wetter than normal in the late fall and early winter
It is now full-on spring and it is still much wetter and colder than normal.
As for the second statement, let's look at some previous La Ni�a's.
Refer back to
this table again and look at the time from mid 1998 through early 2001. That was a monster La Ni�a. The Pacific Northwest had huge precipitation and cold winters but we also had normal springs and hot summers.
The La Ni�a event we are going through is somewhat weaker and is expected to peter out in another three months according to the
latest prediction of April 10th, 2008:
The recent dynamical and statistical SST forecasts for the Ni�o 3.4 region indicate La Ni�a will become weak and persist through May-June-July 2008 (Fig. 5). Thereafter, there is considerable spread in the forecasts, with nearly one-half indicating La Ni�a could continue well into the second half of the year. Based on current atmospheric and oceanic conditions and recent trends, La Ni�a is expected to continue for the next 3 months.
Now what is the difference between the two events, the first being the strong and long-lasting La Ni�a of 1998--2001 with mild effects and the current La Ni�a of mid-007--mid-2008 with strong effects?
The Sun.
The solar output during the first event was high and the output these days is low. A table of Sunspot numbers averaged by month can be found at the National Geophysical Data Center (
main page,
the table)
Look at the numbers for the first event - 1998 started off slow with monthly numbers in the 30's and 40's; 1999 had no months under 50 and two over 140; 2000 only had one month under 100; 2001 had two months under 100.
What is significant about this La Ni�a event is that it happened at the peak of Solar Cycle 23 when the sun's activity was at its highest.
Now look at 2007 -- July had ten sunspots. The rest of 2007 had less than ten per month with October having 0.9 and November with one. December's data is not present. 2008 is quiet as well -- January with 2.3 and February with 1.6.
What is significant about this La Ni�a event is that it is happening at a time between Solar Cycle's 23 and 24 and that the sun is unusually quiet.
We are seeing much lower temperatures over the entire planet.
The primary influence on our climate is the sun -- its variations drive our climate much more than CO2 or any other greenhouse gas. Until the sun's output kicks back up again, we need to keep driving those hummers and burning that fossil fuel.
My concern is that the sun has had several periods of long-term quietness in past times (the
Maunder,
Sporer and
Dalton Minima comes to mind, also the
Modern Maximum) and if we are entering a phase like this, we need to seriously re-think our priorities regarding our money being spent on AGW and the squandering of our food (and I am thinking Globally!) for expensive and Government subsidized fuel...
Posted by DaveH at April 21, 2008 8:46 PM