Short instructions for using sea-surface temperature and sea-ice
concentration CD-ROMs on MS-DOS computers.

You'll need a PC with a 256-color SVGA display, and probably need
eight megabytes of memory.  It may work with less memory.  PC's
are more problematic because the hardware is more diverse than
Macintosh computers; the program should be able to run on many
systems, but may not run on all that seem capable.

You should be able to run these programs from the Windows MS-DOS
box.  This works for me under Windows 95.  But hardware compatibility
might still be a problem.  It will have to run in full-screen mode.

Sea-Surface Temperature (SST):

	Load CD, change to directory "DERIVED"; change to directory
	"DOS"; run program as "SEE MONTHLY.NA".

	For other ocean regions the extension "NA" will be something
	else instead, like "SEP" for the Southeast Pacific.

		If it complains and tells you it's sorry and can't work with
		your video card, try loading the files on the diskette onto
		your hard disk.  If E: is not your CD-ROM drive, edit the
		files MONTHLY.* to change the drive letter at the beginning of
		each line so they describe files on your CD-ROM drive. Then
		try again, from that directory "SEE MONTHLY.NA".  If that
		doesn't work, try "SEE MONTHLY.NA VESA".  If that doesn't
		work, contact me.

	The CD light should go on for a while as the viewer program
	reads the SST data.  Then it should produce a map surrounded
	by some textual information.

	Click on the map; the seasonal changes in surface temperature
	will be plotted.  In the upper left corner of the screen you'll
	see the latitude, longitude, and water depth of the point you
	selected.

	Press PgUp or PgDn to display different months.  Press F2 to
	cycle through the months automatically.  Press G to display
	lines of latitude and longitude.

	Things to look for in the North Atlantic:

	The Gulf Stream, a warm current flowing northward from the Gulf
	of Mexico along the east coast of the United States, brings
	warm water to Northern Europe.  A broad, less dramatic flow
	of colder water returns from Southern Europe westward towards
	the Gulf of Mexico.  The Labrador Current, a narrow river of
	cold water, forms off the east coast of Newfoundland and
	Labrador in Canada, and flows along the northeast coast
	of the United States in the Autumn.

	Three gaps in the mountains of Mexico and Central America allow
	strong winter winds from the Gulf of Mexico and Carribean to
	push aside the surface water of the East Pacific, bringing cold,
	deep water to the surface.  These show up in the images as
	patches of yellow (cooler water) among the red (warm water) on
	the south side of the land.

Sea-Ice Concentration:

	Load CD, change to directory "DERIVED"; change to directory
	"DOS"; run program as "SEE_ICE N".  This gets you the North
	Pole; for the South Pole, change the "N" to "S".

		If it complains and tells you it's sorry and can't work with
		your video card, try "SEE_ICE N VESA".  If that doesn't work,
		contact me.

	The CD light should go on for a while as the viewer program
	reads the sea-ice data.  Then it should produce a map image
	surrounded by some textual information.

	Click on the map; the seasonal changes in sea-ice concentration
	will be plotted.  In the upper left corner of the screen you'll
	see the latitude, longitude, and water depth of the point you
	selected.

	Press PgUp or PgDn to display different months.  Press F2 to
	cycle through the months automatically.

	Press G to display lines of latitude and longitude; Press M to
	display a small box centered on the point where you last clicked.

	Other things to display:

	In DERIVED\DOS, you'll find files like "N.84" which will show
	you the monthly changes only during 1984, and "N.02", which will
	show you the same month (February in this case) of each of the 13
	years for which data are available on the CD.  Likewise, there
	are files named "S.84" and "S.02" for the Southern Hemisphere.
	Run these just as you did for "N"; type "SEE_ICE N.84" at the
	DOS prompt.

	Things to look for in the Northern Hemisphere:

	The Gulf Stream brings warm water from the Gulf of Mexico and
	Carribean Sea all the way to Northern Europe.  Check the ice
	conditions just east of Svalbard (formerly Spitzbergen, the
	group of islands just east of Northern Greenland).  Contrast
	this pattern with the ice concentration at the same latitude
	in the western part of the Arctic Ocean, north of the Pacific.

	The northern part of the Baffin Bay thaws before the central part
	does.  This phenomenon is known as the North Water Polynya.  It is
	thought to be caused by winds and ocean currents, although the
	dynamics are not fully understood.

	The curious ice peninusula just east of central Greenland and north
	of Iceland was known by Norse mariners, who call it the "Odden."
	It is caused by gyral (circular) currents in the Norwegian-Greenland
	Sea.  It tends to occur in different places each year, but is
	consistent enough to show up even in averages of many years.