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Epson Olsen Thanks for the suggestion about pausing animation for last frame for a few seconds. I've updated to most recent value and added the pause. Thanks again. Kelly O'Day animation link
Nevin: Here's a gif animation of the JAXA sea ice extent data through 8/24/12.
Greg Wellman asked "what the heck is this.." Great question Greg! I track the Nini34 status weekly and know that we are in a LaNina. So what is going on,your link shows lots of warm water in Pacific, yet there's a LaNina, right? I went back to my source, NOAA/ NESDIS twice weekly global image If you open the 2 images in separate browser windows you'll see the reason. The Pacific is very large, the warm water in your image only extends to longitude 120 W, the cold water in the Nino region goes from 120 W to 160 W. So your image actually misses the major LaNina cold area. Kelly O'Day
Toggle Commented Sep 30, 2010 on Open Thread 1 at Arctic Sea Ice
Artful Dodger Thanks for the tip on DA and Wang's paper. Do you know where I can get the monthly DA data Wang shows in his paper? His plot goes from 1950 through 2008. It would be interesting to updata it for the 2010 melt season and track it in 2011 season.
Toggle Commented Sep 26, 2010 on Open Thread 1 at Arctic Sea Ice
Great job Nevin. I have enjoyed your thoughtful discussion and the excellent comments. Now that the melt season has ended (I think?), I've been looking at the role the Arctic Oscillation plays in daily SIE changes. Here a plot of JAXA daily SIE change and Arctic Oscillation for the April - August, 2010 period. I've looked at each year from 2005 through 2010 and don't see any relationship between daily SIE changes and AO. I'm curious if you or any of your readers have seen any analysis of SIE change and AO. Kelly O'Day
Lodger I get different Arctic Sea ice Extent minimum dates. This chart shows that 2007's minimum was on 9/24/07, outside your Sept 10-13 range. Kelly
Philip263 I couldn't reconcile your summary for 2008 vs 2010. My analysis shows 2010 still ahead of 2008 by a meager 49,000 km^2, while you report 2008 less than 2010 by 28,437. Ah, leap year does make a difference. I compare on Day of Year, not calendar day. 8/18/10 was day 230 in 2010. Since 2008 was a leap year I compare 8/17/08 with 8/18/10; mystery solved. DOY won't matter once we reach the minimum in mid-late Sept. Kelly
It's now 5 straight days of 2010 SIE decrease being > than 2007 values!! 2010 has reduced 2010-2007 gap by 93,300 km^2 in 5 days. While 2010 - 2007 gap is -676,000 km^2, there are 41 remaining daysl for 2010 to match the 2007 minimum SIE. Kelly O'Day
8/13 makes the 4th day that 2010 has SIE decrease has been greater than the comparable 2007 decrease. 2007 Sum Last 4 days = -186.1 2010 Sum Last 4 days = -255.9 Delta 69.84 Delta avg - 17.46 The 2007 - 2010 gap has dropped below 700,000, it now stands at 699,200. There are still 42 melt days. 2007 averaged 26,800 km^2 decrease for these 42 days. 2010 will break the 2007 record if 2010 averages 43,400 (16,600 more than 2007) for these next 42 days. It's not over yet!! Daily charts here. Kelly O'Day
2010 has decreased 48,800 km^2 over 2007 DOY values in past 3 days, 16,300 per day. With 43 more melt days, 2010 needs to average 17,000 km^2 more decrease per day to catch 2007. I find watching the daily difference chart link helpful.
L Hamilton Just checking to see if you took the non stationary aspect of the data series into account. I'm still trying to understand spurious correlations of time series, so I may be over reacting, This post provides some background on problems with ordinary least squares analysis of time series. Kelly O'Day
The 2010 - 2007 difference has dropped from 607,000 of 7/29 to 514,000 on 8/2, so I think the race is still on, and it's a marathon at that. The key is daily changes. With 50+ melt days left, 2010 only needs to average 10,000 km^2 more than 2007 to exceed 2007. I'm tracking the 2010 and 2007 daily losses here: 2007 had 4 straight -100,000 km^2, then the 2007 loss rates drops off. The race is not over yet.,
Lord Soth You sound like a real Photoshop guru so I hesitate to suggest ImageJ, but what the heck. For those not familiar with it, ImageJ is a free Java based image analysis toolkit that is used widely. It is supported by NIH for medical image analysis, however applications extend far and wide. There is an active and helpful user base. It lets you do set scale so that you can get real world coordinates as you navigate the image. It also lets you establish Regions of Interest (ROI) that you can analyze time trends over a number of images. I've got a brief tutorial and video on how I have used it to track Nino34 temperature trends in the Pacific Link. I've been hoping to set up a series of tutorials on how to use ImageJ to track Arctic Sea Ice conditions. I'd be very happy to work with you to make a user friendly ImageJ arctic sea ice analysis tool. I understand if you'd rather stay with Photoshop. I'm hoping to provide a free open source tool that can handle animations and data extraction for a wide audience. Kelly
I have found the Cryosphere Today's long term sea ice area anomaly chart Tail of the Tape difficult to interpret because of its awkward size. I've made a daily anomaly chart that shows the entire record in a single window here. I'll be updating daily through September. It's viewable from my Arctic Update page. Kelly
Neven I really like your animations. Can you share some details on how you make them? I use ImageJ, what software do you use? How do you label your individual images with year and day of year. I find that very helpful in following time sequence.
Neven I've been experimenting with how to show the changes in rates of daily SIE decline for 2010 and 2007. I've been using a table of comparative rates for previous periods. My latest attempt plots the actual daily 2010 - 2007 SIE differences. Here's a link my latest attempt: Which display method do you prefer, the data table of rates or the differences plot? If I put both the data table and the difference plot on the same display with the SIE trends, the text is unreadable. I'd appreciate feedback on which method is easier for readers to pick up changes in the 2010 versus 2007 situation.. I plan to start plotting the 2010 - 2007 Cryosphere Today Sea Ice Area data and would like to use the same plot layout for both SIE and SIA. Kelly O'Day
The 2010 - 2007 SIE delta is actually -0.644 million sq km. Kelly
JAXA has reported 6/29 SIE decline of 81,000 sq km. Since the comparable 2007 was 120,000 sq km, the 2010 - 2007 delta has reduced ever so slightly to 0.66 million sq km. The race is still on. My latest charts are here Kelly O'Day
Agree. 2007 decrease rate picked up in late June, held during July - August. Notice how 2006 lost out to 2007 in late June, never regained lead. Questions is whether 2010 will match the 2007 rates. If not, then the current 0.6 million km^2 2010 delta will decrease, depending on differences between 2007 and 2010 decline rates. It's a foot race, 2010 has lead, however, 2007 has recently picked up some speed over 2010. Can 2007 catch up? It all depends on their relative speeds.
Toggle Commented Jun 28, 2010 on Sea ice extent update 8: ...go! at Arctic Sea Ice
Gneiss Your table shows that the 2010/2007 decline ratio has been decreasing over June. 1st period: 68646/48646 = 1.41 2nd period: 64828/52578 = 1.23 3rd period: 86894/82328 = 1.06 This tells me that 2010 is shifting from a much greater decline rate in early June to close to 2007 at end of June. If the declining ratio trend drops much below 1, 2010 will be lower than the 2007 minimum level. Only time will tell. Kelly
Toggle Commented Jun 28, 2010 on Sea ice extent update 8: ...go! at Arctic Sea Ice
Gneiss Both graphs and tables have their roles. I think of them as hammers and screw drivers. I need both for my handyman jobs. Your June-to-date table is accurate and helpful. However, the net decline rate does not tell me if there is a change in the decline rate over the period. Was most of the decline in the beginning, at the end or was it uniform throughout the period. It also does not tell me where we started the month of June. Where was 2010 in relationship to the other years? Was 2010 higher, lower than 2007? Here's a combination table and chart that I'm currently using to help me track the Arctic Sea Ice Extent situation I'd like to hear your thoughts on this approach. Kelly O'Day
Toggle Commented Jun 28, 2010 on Sea ice extent update 8: ...go! at Arctic Sea Ice
Neven Sure - I'd be honored to have you link to my snapshot table. I've been changing the name each day. To simplify things, I'll start using a constant name in a few days. In the meantime, feel free to copy it to your blog. Kelly O'Day
Toggle Commented Jun 27, 2010 on Sea ice extent update 8: ...go! at Arctic Sea Ice
In watching JAXA 2010, I've noticed that the while the 2010 rate of decrease in extent has been greater than comparable 2007 rates, the 2010/2007 ratio has been dropping and the June 26, 2010 rate is slightly lower than the 6/26/2007 rate. What does this mean?? There are approximately 75 days until SIE minimum (mid Sept). The July - mid August 2007 decline rate was precipitous. For 2010 to be a record breaker, the 2010 decline rate will need to keep pace with the 2007 rates. Since the 2010 rates are now similar to 2007 rates, we'll have to continue watching the rates for a while to see 2010 will pan out in comparison to 2007. I have a daily update at Kelly O'Day
Toggle Commented Jun 27, 2010 on Sea ice extent update 8: ...go! at Arctic Sea Ice is now following The Typepad Team
Jun 27, 2010