During diurnal darkness in Alaska, is it possible to view the Southern constellations?

No. What you would see are the constellations that would otherwise only be visible in the summer.
If I can find a good site with a graphic for this situation, I will post it. If not, I will attempt to describe it.

One of my students and I were reading a book Julie and the Wolves which is set in Alaska and it stated that during the day the Southern Constellations were visible...guess we'll have to write the author because it didn't seem to make sense to us...thanks for your response...

I'm glad you're willing to take your instincts and my word for it, but let me see if I can explain anyway.

I couldn't find an image intended for this purpose, so this one will have to do.

Imagine that there are stars off in the distance in all directions (or at least to the left and right and up and down since it's 2-dimensional)

The stars in the upper portion are the Northern constellations, the ones in the lower portion are the Southern constellations. Since we're dealing with the Northern hemisphere, the stars to the left are the winter constellations and the stars to the right are the summer constellations.

For someone in the northern hemisphere, the earth blocks their view of the southern constellations (they are below the horizon). During the winter, the summer constellations (to the right) aren't visible because the sun is up when we the we would otherwise be able to see them. The reverse is true in the summer.

At some point in the winter in the far north, however, the earth gets in the way of the sun even during the "day". But, as you can hopefully see from the picture, this is because you would be looking to the north of the sun, so only the northernmost constellations would be visible. These constellations, however, are the summer constellations (to the right), which would normally not be visible except in the summer.

Too late to edit, but, at the very end there, I should have said "...(to the right), some of which would not normally..."

Thanks for the info and explanation, but I'm not sure we understand -- for example, could the Southern Cross be seen in Alaska during diurnal darkness?

short answer, no the southern cross would not be visible.

hmm ... i hope this is clearer, but i'm having a hard time figuring out how to do this any better with just words and the pictures i can find on the web. Everything I'm about to say applies in the northern hemisphere ... insert the word south every time i say north and north every time i say south for the situation in the southern hemisphere)

There are two things that will block your view of stars. One is the sun, the other is the earth's surface.

First the earth's surface: The further south you are, the more southern constellations you will be able to see and the fewer northern constellations you will be able to see. The horizon gets in your way. The southern cross is far enough south that the earth's surface gets in the way.

The sun: As the earth rotates, different constellations come in and out of view. If you watch any star through out the night, it makes an arc in the sky (centered on approximately the position of the north star) just like the sun does. So stars, except for those that are far to the north, rise and set like the sun (those in the north do the same thing, but their arc never takes them below the horizon). If a star is on the same side of the earth, it will rise and set with the sun and you won't be able to see it. But when the earth moves to the other side of the sun, the star and the sun will no longer be on the same side, so you will see it. This is (mostly) why we have winter and summer constellations.

does this make any more sense?

Yes, thank you for your patience with us in explaining the role of the horizon in blocking our view of such constellations as the Southern Cross. I am assuming that even though the North Star is at the sky's zenith, that it cannot be seen from the very south of the Southern Hemisphere for the reasons you explained. Is that right?

Thanks again...dr.mlm

Yes, the more northern stars (like the North Star, which is the northernmost) cannot be seen if you go too far south.