Air Quality in Alaska........

[seatrial]

Last year I took my first trip to Alaska on the Summit northbound, August 1. As we progressed northward toward Valdez I noticed that the sky seemed more and more hazy, somewhat like the summertime sky in the south, however, there was little humidity in Alaska. I asked several people, including navigational crew on the ship; no one had a good answer. Finally a shopowner in Valdez suggested that the haze was smoke from forest fires in Russia. Has anyone noticed hazy skies in Alaska this year? When I go back and look at the digital pictures from my trip it is really shocking how hazy the skies are up in the Valdez area. College Fjord looked like a bad smog day in Atlanta in July. Anyone else notice this last your or this year? Thanks.

[Gardyloo]

There are several possible explanations or combinations of reasons.

 

First is smoke - there are wildfires in Alaska annually, sometimes enormous ones, that can cauze haze very far away. Sometimes the winds aloft will be blowing in a different direction from those at sea level, so seeing smoke from the north or west is not impossible, even if the surface winds are coming from the south.

 

Second is "vog" - volcanic smoke (or when it's really bad, fog) - that also can be from eruptions far away - on the Aleutians, Kamchatka, wherever. Many is the flight from Anchorage to Asia in days gone past that had to cancel or divert due to eruptions of volcanoes along the Alaska Peninsula/Aleutian Chain, the dust from which the airlines didn't want their engines to inhale.

 

Moisture, good old heat haze, is another. Temperature inversions (ie warmer aloft than on the ground) are not uncommon in Alaska, thus ordinary mist can layer up.

 

But most likely, especially in areas where there are nearby mountains and/or icefields, the haze is caused by good old dust, blown aloft by good old wind passing over/around/through areas of glacial "till" - the very fine powder that glaciers leave in their wake. As meltwater recedes in the summer, the silt and dirt left high and dry simply turns into incredibly fine dust, which gets blown up into the atmosphere and stays there. Many of the particles are even too small to form the core of raindrops. When you see a glacial river in Alaska (like, say, the Kenai or Big Su) the greenish tint is the glacial till; when that water hits a delta or tide flat, the little particles get deposited, then they dry, then they go on a little flight. Hence haze.