On Tue, 22 Jan 2008 20:14:17 -0800 (PST),
Weatherlawyer , in
wrote:
+ Someone tell me how a warm pool in the south Pacific can affect the
+ north Indian without the ability to cross the equator.

Well, actually the warm pool exists on both sides of the equator.

+ La Niña develops when stronger-than-average trade winds push the warm
+ surface waters of the equatorial Pacific west. Since cold water rises
+ to replace the warm water, La Niña leaves the eastern and central
+ Pacific Ocean much cooler than normal, while the western Pacific is
+ much warmer than normal.
+
+ These anomalies in sea surface temperature are mirrored in rainfall
+ patterns, with warmer-than-normal temperatures resulting in enhanced
+ rainfall. In general, La Niña brings unusually heavy rain to the West
+ Pacific, Indonesia, parts of South east Asia, and northern Australia.

So, for both La Niña and El Niño the warm pool is offset from an
"average" position. During El Niño, it shifts to the east so that it's
closer to the western hemisphere. And during La Niña, it shifts to the
west, so that it's closer to Asia/Northwest Australia.

And the convective thunderstorms develop over the warm pool. In turn,
they act to anchor the subtropical jetstream, which changes its
position in the mid-latitudes, and thus influences the larger weather
pattern.

So, during La Niña you get more rain in Manila than you would expect,
and less over Peru. And during El Niño, you get more rain in Peru than
you would expect, and less in Manilla.

--
Consulting Minister for Consultants, DNRC
I can please only one person per day. Today is not your day. Tomorrow
isn't looking good, either.
I am BOFH. Resistance is futile. Your network will be assimilated.