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

You'll need a Mac with a 256-color display, and probably need eight
megabytes of memory.  It may work with less memory.

Sea-Surface Temperature (SST):

	Load CD, open folder "Derived"; open folder "mac";
	open folder "MacSee"; launch application "See SST".

	Click OK, click OK again, then choose a region of interest
	from among the folders given, like "North Atlantic".

	Choose the file "mq_list.na" and click Open.  For other ocean
	regions the extension "na" will be something else instead,
	like "sep" for Southeast Pacific.

	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 window 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.

	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, open folder "Derived"; open folder "mac";
	open folder "See Ice"; launch application "See Ice".

	Click OK, click ok again, then select and open either the
	file "n" (for the North Pole) or "s" (for the South Pole).

	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 window 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.

	Select options under the View menu to display lines of latitude
	and longitude or to show a small box centered on the point
	where you last clicked.

	Other things to display:

	When you see the file dialog from which you selected "n" or "s",
	you'll also see folders "Annual" and "Interannual".  In these
	folders, 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.

	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.