I promise that this will be my last question today!!

Thank you for your question.  It is a little complicated to answer, so I asked one of our Physical Oceanographers on board, Dr. Ned Cokelet of NOAA'S Pacific Marine Environmental Laboratory, to explain it.  Physical Oceanographers are physicists who study the ocean.  Here's his answer:

Your question is an astronomical one because it has to do with Earth's orbit around the Sun.  The compass directions where the Sun rises and sets are called the sunrise and sunset azimuths.  You could Google these phrases on the www to find out more, just as I did to brush up on my answer to you.  We usually say that the Sun rises in the east and sets in the west.  It would be more accurate to say that the Sun rises in the eastern sky and sets in the western sky.  The sunrise and sunset azimuths are not exactly east and west.  These azimuths depend upon the observer's latitude and the day of the year.  Yesterday when you asked your question, the sunrise and sunset azimuths at San Francisco, California (at 38 degrees north, near to your latitude of 40 N), were 65 and 295 degrees.  East is 90 degrees on a compass, and west is 270 degrees.  So you can see that at San Francisco, the sun rose 90-65=25 degrees north of east and set 295-270=25 degrees north of west.  However at Anchorage, Alaska, the sunrise and sunset azimuths were 45 and 315 degrees, respectively.  That means that at Anchorage (which is at about 61 degrees north latitude, close to where Healy was yesterday at about 62 N) the sun rose 90-45=45 degrees north of east and set at 315-270=45 degrees north of west.  So the sun rose in the northeast and set in the northwest yesterday for us aboard ship.  At the North Pole, the sun did not rise or set yesterday.  It just circled overhead.  

All this comes about because Earth orbits the Sun once a year, and Earth rotates about its axis (through the North and South Poles) once a day.  This rotational axis is tilted about 23.5 degrees from the flat plane (called the plane of the ecliptic) defined by Earth's orbit around the sun.  In summer in the northern hemisphere, the northern part of the axis is tilted toward the Sun.  That's why the North Pole is in constant sunlight, and we have longer days than nights in the northern hemisphere.  It is also why the sunrise and sunset azimuths are not due east and west all the time at all latitudes.  

You could read more about this, but it's easiest to understand if you do an experiment.  Poke a pencil straight through an orange and think of the entry and exit points as the North and South Poles.  Now shine a light onto the orange in a dark room and tilt the orange's North Pole toward the light (your model Sun).  You will see that even though you spin the orange (your model Earth) about its poles, the light always hits the North Pole but never the South Pole.  That is analogous to the light in the northern hemisphere summer.  You will also see that somewhat down from your orange's North Pole where we are on Healy right now at about 62 N, the sun rises on the edge of the light-dark boundary in the NE and sets in the NW.  (Earth spins counterclockwise looking down on it toward the North Pole.)  You can try other tilts to mimic other seasons of the year.

I hope my explanation makes sense to you.  Reading more about it on the www is an excellent way to learn more (and maybe pick up things that I glossed over!)  

Ned Cokelet, NOAA/PMEL, Seattle, WA, USA.