Date: Wed, 26 Feb 1997 09:00:44 +0000 (GMT)
From: Jason Goodman <sci5@knorr.whoi.edu>
To: seadiary@MIT.EDU
Subject: science & comets
Message-Id: <Pine.SUN.3.91.970226083858.28728A-100000@mike.knorr.whoi.edu>
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57 30' N, 53 23' W
Winds: nnw, 15 m/s  Temp: -3 C
Seas: calm

  The sky cleared up a little now and then tonight; I went outside for 
half an hour after work, and after we passed through a snowshower, it got as 
much as 50% clear.  Pretty warm, too.  The moon silhouetted the snowstorm 
behind us in a rather stunning fashion: kinda like a cloudy sunset in 
black-and-white.  The sky to the east cleared up, and there was comet 
Hale-Bopp!  At the moment, it's probably brighter but less impressive 
than Hyakutake was: it's heading toward us, so its tail is foreshortened, 
and this is made worse by the nearly-full moon.  But if you happen to be 
up after 3 a.m., you should definitely have a look.  As I recall, it'll get 
brighter and rise earlier until its maximum in late March.

  Our data suggests it's probably going to be a poor year for convection
in the Labrador Sea.  But not in the way you expected, John.  (Everyone,
meet John Marshall, my advisor.) We expected fewer storms this year, and
therefore less cooling of the ocean surface.  But this year's surface
mixed layer is the same temperature as the Lab Sea water formed last year,
so the cooling's about the same.  However, it's _much_ fresher this year. 
The less-salty water is lighter, so it needs to be much colder than it is
to sink.  If this year's mixed layer had the same salinity as the water
formed last year, we'd already be convecting to 1800 m (that's the event
we'd hoped to see.) But the best we've seen is 1000 m.  It's unclear
whether the fresh water comes from snowfall into the sea or from melting
ice in regions surrounding it... but it _has_ been snowing an awful lot. 

					J