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Raining Fish
Mon Mar 24, 2003
Listen in RealAudio 
Salmon swim in the sea. Rain falls from the sky. So why on earth are scientists at the
Pacific Marine Environmental Lab studying Alaska salmon populations by flying into torrential
rainstorms? Hi, I'm Bryan Yeaton for The Weather Notebook.
The answer, says PMEL research meteorologist Nick Bond, has to do with a fascinating
connection between fresh water runoff, turbulent ocean currents, and the well-being of young
Alaskan salmon. Bond explains that, after a series of really big storms in the Gulf of
Alaska, there is so much runoff that a freshwater lens forms on top of the ocean's denser salt
water. The contrast between these liquid layers generates oceanic instability in much the
same way that storms brew in the atmosphere from collisions between warm and cold air masses.
And for some reason that scientists don't fully fathom, pink salmon seem to thrive when the
ocean is churned up -- in other words, when the weather is stormy. The numbers speak for
themselves: During the wet period of the late 1970s through the early 1990s, Alaska's annual
pink salmon catch was around 70 million a year, almost seven times the annual catch during the
relatively dry spell from the 1950s through the mid 1970s.
Up in Alaska, everything is on a gigantic scale, including the weather. A "routine" storm can
dump over 11 inches of rain a day on the coastal mountains. In their next Alaskan jaunt, Bond
and colleagues plan to fly into really juicy coastal storms while simultaneously dropping
sensors into the ocean. Once air and sea readings are combined with salmon data, the results
promise to be spectacular, putting researchers in the pink.
The Weather Notebook is funded by Subaru and The National Science Foundation.
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