The Meso and Micro Scale Climate of Valdez, AK

Of the four mesoscale influences listed in the class lecture, Valdez Alaska experiences all of them: orographic, water, atmospheric circulation, and air mass influences. As mentioned in previous blog posts, Valdez is nestled between the Chugach mountain range and the William Sound of the Pacific Ocean. The Chugach mountain range has significant orographic influences on the city of Valdez, forcing air masses from sea level to over six thousand feet--giving birth to monumental snowfall from moist air masses blowing in from the Aleutian Low and Bering Sea. The William Sound and the Pacific Ocean also influence the mesoscale climate of Valdez. Because water heats up and cools down faster than land, Valdez experiences a more moderate temperature range than other towns in Alaska as more energy goes into the latent heat flux and not the sensible heat flux. The Aleutian Low that sits to the west of Valdez in the Bering Sea also has a tremendous effect on Valdez's climate. Especially during the winter months, the high pressure that is initiated by the cold, heavy air of inner Alaska and the northern arctic creates a pressure gradient with the Aleutian Low to form enormous storms. Finally, the air masses that affect the mesoclimate of Valdez include the maritime polar, continental arctic and continental polar air masses. In the winter months, the continental arctic and polar air masses influence the area more, whereas the maritime polar air masses influence Valdez more in the summertime.

Source: http://minnesota.publicradio.org/collections/special/columns/updraft/archive/2010/02/forecast_last_arctic_blast_of.shtml

In addition to mesoscale climatic effects, there are also numerous microscale influences on Valdez. Valdez sits at the base of a river valley that extends up into the Chugach. This has several effects on the microclimate, including windy conditions and cold air ponding. Cold air hugs the lowest elevations, and the river valley funnels the cold air from the mountains down into Valdez, but it also funnels wind from the high pressure gradient forces that Alaska is known for. As for anthropogenic effects on Valdez's climate, there are few because people are sparse and the environment as a whole is effected very little by the activities of Valdez. To my knowledge, there are no invasive species issues, smog, irrigation, or other anthropogenic influences in the are.

Aerial view of Valdez, AK sitting between the Chugach and William Sound

http://www.alaska-in-pictures.com/port-of-valdez-aerial-3068-pictures.htm

The Koppen Geiger scale classifies Valdez as a DFC, where they experience a snowy climate, very humid conditions, and a cool summer, which accurately depicts the climate of Valdez according to my observations.

Aerial photo of Valdez Airport where the weather station I am using is located

http://www.airphotona.com/image.asp?imageid=12109

It is difficult to get annual precipitation data from the weather stations in and around Valdez; only one of the four stations had precipitation data. Of the data that I could find, the year of 2011 has been very dry in Valdez with only 21 inches of precipitation, whereas 08', 09', 10' saw 37 inches, 42 inches, and 33 inches respectively. There is still one month left in the year for Valdez to make up some ground, but historically they don't see much precipitation in December. In reference to temperature, I did have access to temperature data dating back to the 70's; however, there was no consistent pattern of temperature swings that I could determine from the monthly data that was available.

Source: http://www.wunderground.com/weatherstation/WXDailyHistory.asp?ID=MRHVA2&graphspan=year&month=12&day=1&year=2011