tag:blogger.com,1999:blog-4572286363399496963.post8597053542924031856..comments2024-03-18T16:56:29.399-08:00Comments on Deep Cold: Alaska Weather & Climate: Snow Depth ThoughtsRickhttp://www.blogger.com/profile/03946704894714514716noreply@blogger.comBlogger8125tag:blogger.com,1999:blog-4572286363399496963.post-75555389480183409112013-12-07T17:29:28.834-09:002013-12-07T17:29:28.834-09:00I may as well throw this into the pot. I've ob...I may as well throw this into the pot. I've observed these rain and melt events impacting subsequent snow levels, rates of sublimation, and snow texture. <br /><br />Once the existing snow cover is "sealed" with a surface layer of ice, it can remain in essentially a fixed state and level until Spring. More snow and wind may cover but not disturb as easily, and the snow under the cap can change states to a more granular nature like small ball bearings (corn snow).<br /><br />In March and April the surface covering the ice layer will melt or sublimate normally , but the sealed layer takes some longer time to disappear. It's really apparent on lakes with ice covered drifts that linger longer than normal snow would.<br /><br />GaryNL7Yhttps://www.blogger.com/profile/15874712728971005352noreply@blogger.comtag:blogger.com,1999:blog-4572286363399496963.post-79556105665793021252013-12-07T11:34:15.221-09:002013-12-07T11:34:15.221-09:00Good suggestions, Eric - I'll see if I can dig...Good suggestions, Eric - I'll see if I can dig up anything. Initial query of the data shows slightly higher snow and snow depth in negative PDO years, but similar ratio of the two.Richard Jameshttps://www.blogger.com/profile/08313902028896263276noreply@blogger.comtag:blogger.com,1999:blog-4572286363399496963.post-60913228872765631142013-12-07T11:15:48.180-09:002013-12-07T11:15:48.180-09:00Thanks Brian, that's a useful chart. So densi...Thanks Brian, that's a useful chart. So density does follow quite closely with total snow, as we expect from compaction; the 90's was a time of high snowfall and high-density snowpack. The trend does appear to have reversed.Richard Jameshttps://www.blogger.com/profile/08313902028896263276noreply@blogger.comtag:blogger.com,1999:blog-4572286363399496963.post-62470386116797798072013-12-07T11:09:23.189-09:002013-12-07T11:09:23.189-09:00Gary,
Good points, thanks. It seems the official...Gary,<br /><br />Good points, thanks. It seems the official observations have been made at the airport since 1951, but I don't yet know if there have been any changes in the precise location or methods in that time.<br /><br />In looking around, I found the following link which contains a nice history of all NWS office locations past and present for all 50 states:<br /><br />http://www.crh.noaa.gov/ilx/?n=nws-wb-history<br /><br />Richard Jameshttps://www.blogger.com/profile/08313902028896263276noreply@blogger.comtag:blogger.com,1999:blog-4572286363399496963.post-41134769325901610282013-12-07T10:37:46.253-09:002013-12-07T10:37:46.253-09:00I'd first be looking at Methods and Means for ...I'd first be looking at Methods and Means for determining snowfall and depth in Fairbanks. If it's been documented and consistent then perhaps other factors have come to play a role. Where and how did they do the measurements over time? <br /><br />The Fairbanks airport is subject to human activity...aircraft generated winds and snow being redistributed via huge blowers off active surfaces. <br /><br />GaryNL7Yhttps://www.blogger.com/profile/15874712728971005352noreply@blogger.comtag:blogger.com,1999:blog-4572286363399496963.post-31891141570457268242013-12-06T23:04:18.477-09:002013-12-06T23:04:18.477-09:00Perhaps there is too much variability but you coul...Perhaps there is too much variability but you could do a scatter plot of average temp vs any of the snow properties over the various periods of time. Any patterns might give insight into the temp's role.<br /><br />Also, the snow depth graph reminded me of the century temp graph. How does the PDO factor?Eric Lundellhttps://www.blogger.com/profile/17914784378747801359noreply@blogger.comtag:blogger.com,1999:blog-4572286363399496963.post-19798025195128553062013-12-06T21:00:22.184-09:002013-12-06T21:00:22.184-09:00Thank you looking into this some more Richard. In ...Thank you looking into this some more Richard. In a week or so I'll have more time to look into this but the GHCN database does have snow water equivalent data for 1952 through 2000. I took the liberty of adding a single chart to the end of your post without any additional text. It shows the snow depth, snow water equivalent (SWE), and the snow density (depth divided by SWE) for all February's between 1952 and 2000. Interestingly, the trend is toward greater density (more compacted) snow pack particularly since the 1980s. Perhaps that trend has reversed and the relationship between snowfall and snow depth has returned to the pre- 1981-2010 climate normal period level. Alternatively, I would hypothesize that perhaps more of the snow is falling in the colder time of year now (as a proportion), it is more likely to form in the atmospheric dentritic growth zone and is therefore fluffier. Climatologist49https://www.blogger.com/profile/04560505931210357679noreply@blogger.comtag:blogger.com,1999:blog-4572286363399496963.post-54757019836782978432013-12-06T19:17:37.350-09:002013-12-06T19:17:37.350-09:00Excellent learning source for we readers. Thank yo...Excellent learning source for we readers. Thank you Richard.<br /><br />Not sure of the source but Rick has either written here, presented info in formal seminars, or written personal notes regarding the moving of observation locations over time. I recall reading about the changes. He may offer a clue re: Any mid-'80's change and its potential effect on snow data.<br /><br />In the meantime, here's some source material that mentions potential changes in location:<br /><br />http://oldclimate.gi.alaska.edu/papers/Arctic62-3-295.pdf<br />http://climate.gi.alaska.edu/history/Interior/Fairbanks.html#Fairbanks%20Temperature%20History<br /><br />GaryNL7Yhttps://www.blogger.com/profile/15874712728971005352noreply@blogger.com