Support the Arctic Sea Ice Forum and Blog

Author Topic: Model projections vs observations.  (Read 776 times)

Michael Hauber

  • Grease ice
  • Posts: 900
    • View Profile
  • Liked: 76
  • Likes Given: 14
Model projections vs observations.
« on: June 20, 2019, 03:13:07 AM »
A quick hunt for model predictions on Arctic extent finds Huang et al

Figure 3, to which I've added a circle to show that the models predict that we should currently be somewhere near 4m in September extent:



Last four years NSIDC September monthly:
2015             4.62
2016             4.53
2017             4.82
2018             4.71

Last four years JAXA minimum daily:
2015               4.26
2016               4.02
2017               4.47
2018               4.46

Obs copied from the June poll threads.
« Last Edit: June 20, 2019, 03:19:51 AM by Michael Hauber »
Climate change:  Prepare for the worst, hope for the best, expect the middle.

Archimid

  • Young ice
  • Posts: 3363
    • View Profile
  • Liked: 855
  • Likes Given: 204
Re: Model projections vs observations.
« Reply #1 on: June 20, 2019, 04:24:48 AM »
Fascinating paper.

Out of 31 CIMP5 models they pick the 6 that best approach current trends. With it they determine 2054 as the date of the first virtual ice free. No bounds or uncertainties in the preview that I can see but judging by Michael Hauber's image according to the models best performing models the next decade (2020's) is not out of the question and down right likely if the ensemble stdev is 1 sd not 2 sd as I hope it is.

Now lets hope that CIMP5 is not underestimating like CIMP4.
I am an energy reservoir seemingly intent on lowering entropy for self preservation.

TeaPotty

  • Frazil ice
  • Posts: 236
    • View Profile
  • Liked: 47
  • Likes Given: 75
Re: Model projections vs observations.
« Reply #2 on: June 20, 2019, 04:30:14 AM »

Michael Hauber

  • Grease ice
  • Posts: 900
    • View Profile
  • Liked: 76
  • Likes Given: 14
Re: Model projections vs observations.
« Reply #3 on: June 20, 2019, 06:57:13 AM »

Out of 31 CIMP5 models they pick the 6 that best approach current trends. \

thanks for pointing that out, I didn't spot the fact they'd selected a subset of the models.

I have attempted to update the chart from Stroeve et al as best I can freehand with the pale blue to see how the wider multi-model ensemble compares to recent obs.

Climate change:  Prepare for the worst, hope for the best, expect the middle.