River ice in Alaska: "pretty good proxy for climate change in the 20th century"

This geophysicist would be well inspired to know something about atmospheric circulation before drawing conclusions about the climate from one record…
REPLY: You mean like the conclusions drawn only from Arctic Sea Ice? – Anthony

“By this measure, spring comes to central Alaska 10 days earlier than in 1960, said geophysicist Martin Jeffries at the University of Alaska, Fairbanks”
All very nice, except this compares what happened after a positive PDO. Do the same comparison in 30 years or so, after a negative PDO has wrought its magic. Or better yet, if the records are so good, what’s the entire history reveal of the ebb and flow of ice melt dates, not just a select period that follows a positive PDO.

Heh.
What’s the correlation between ice thickness and time of breakup?
Seems like it would be more related to water rise and fall and river height rather than thickness.
I can see breakup being delayed in drought years. And being early in years with a lot of sunshine.

Other Ice data
http://www.aos.wisc.edu/~sco/lakes/monona-dur.gif
http://www.aos.wisc.edu/~sco/lakes/mendota-dur.gif
http://www.mainelakecharts.com/ice_out07.html

Is it just me, or is there something wrong that causes what should be a graph or something to appear as code?

Average for years 1960-1968 = 8 May
Average for years 1990-1998 = 29 April
Average for years 2000-2008 = 1 May
Sorry but this might show it got warmer in the 1990’s but it pretty clearly shows it has got colder since then.

REPLY: No need to be sorry, it did get warmer in the 90’s – Anthony

Makes me think of how people watch cherry blossom in Japan. Here is an extract from wiki
“The blossoming begins in Okinawa in January and typically reaches Kyoto and Tokyo at the end of March or the beginning of April. It proceeds into areas at the higher altitudes and northward, arriving in Hokkaidō a few weeks later. Japanese pay close attention to these forecasts and turn out in large numbers at parks, shrines, and temples with family and friends to hold flower-viewing parties. Hanami festivals celebrate the beauty of the sakura and for many are a chance to relax and enjoy the beautiful view. The custom of hanami dates back many centuries in Japan: the eighth-century chronicle Nihon Shoki (日本書紀) records hanami festivals being held as early as the third century CE.”
I wonder if there are any long term records of this???

Will be interesting to see this year’s break up.
MN going to +5 F tonight. Snow.
Record snow in N.D.
90% ice cover Lake Superior.
Maybe the wonks can be hoisted on their own petard with this one.

Leif:
See the link that Peter Hartley provided.
http://www.john-daly.com/nenana.htm

I live on the west coast of BC, but much further south.
I see 1964 was the latest breakup year.
We’ve got snow on the ground today, its damn cold and we broke lots of snow records from 1964 this winter. We had 4 feet of snow fall in 35 days in Dec/Jan where we normally have just rain.

I keep a yearly update of the Nenana-Ice classic results at my website (under Climate). Last update dates from May 08. Evolution can be seen in this graph:
http://users.telenet.be/j.janssens/Nenana08.png

Something I don’t see covered very well in this article is what is being dumped in the river today as compared to 1917. There are many chemicals that end up on today’s roads and winter storms and spring rains wash these chemicals into the river.
What affect would different chemicals have on the river whether salt to keep the roads clean or some factory that may be polluting the river?