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Thursday, May 24, 2012

The Antarctic is Getting Some Scientific Love

There is a new paper out on the Antarctic climate change.  The paper by Orsi, A. J, Cornuelle, D. B. and Severinghaus, J. P., Little Ice Age cold interval in West Antarctica: Evidence from borehole temperature at the West Antarctic Ice Sheet (WAIS) Divide, has and interesting chart.

The ice core data is compared to the Steig et al, 2009 temperature fabrication and a cloud masked satellite data series.  The match with Steig et al is generally poor with the exception of the more modern period which was not an issue in Steig et al. and a better but not all that outstanding match with the cloud masked satellite data.  Finding a reliable and long Antarctic temperature series is not all that easy.  It is a rough place which is rough on people and equipment.  So since I like being helpful, I tried a little trickery on the Amundsen-Scot temperature record downloaded from GISStemp.


The trickery is pretty simple.  Amundsen-Scot is very cold year around.  So temperature anomaly may not be all that meaningful.  Energy anomaly might be more meaningful.  Since the source of the ice was water somewhere in the area at or near freezing, I converted the Amundsen-Scot temperatures to Watts, determined the anomaly in Watts, added that anomaly to the energy at o degrees C (273.15K degrees) and converted that to temperature anomaly.


Why?  Because it was raining and I was playing with my spreadsheet.  Actually, the oxygen isotope ratio in the core would relate to the temperature of the water forming the ice more than to the local temperature.  Since Orsi and gang used the 1986 approximate satellite record start, here is my little contribution with a 1986 start.


While the scale I use doesn't look that menacing, the slope of the regressions are in the ballpark of Orsi and gang.  Note that the orange curve slope is a good bit less than the blue curve slope.  A smaller change in temperature at 0 C can produce a larger impact on a area at -45C.  So there has been considerable warming at Amundsen-Scot since 1986.  There would be even a greater rate of warming starting in 1995 when the stratosphere temperature shift occurred and even more starting in 1999 following the super El Nino.  


What about starting at the beginning of the Amundsen-Scot records?




There is minor warming for the full record which would be a better match for their reconstruction.  Imagine that?


Now if Orsi and gang really want to wow the masses, they could compare sea ice variation with their reconstruction and find out where that ice came from.  


Early I said that the oxygen isotope ration in the ice core would relate more to the energy of the water that formed the ice, so why is there a pretty good match with the Amundsen-Scot surface temperature?  That snow is delivers a good portion of the energy that reaches Amundsen-Scot, especially in the winter. 


UPDATE:  I redid the Amudsen-Scot with a 60 month centered moving average and rescaled to overly the Orsi et al. chart.






Note that the time scale is shifted back about four years.  That may be a product of my smoothing, but more likely a product of the nature of the Antarctic.

Wednesday, May 16, 2012

Just Modulatin'

When I threw together the deviation from mean of the Mauna Loa above I used the full average monthly variation which includes the rising trend in CO2 concentration. Nothing good or bad about that, just should be noted. Also the right Y-axis is for the deviation from mean.
This is the deviation from mean using the full Mauna Loa record with the trend in CO2 removed. This is just the monthly change as provide by the NOAA minus the average monthly change. This is on the same Y-axis to show the magnitude of the deviation. Comparing the two may be useful to see what impact the increase in CO2 concentration has on some of the variability in climate.
Just in case you were wondering, here is the average Mauna Loa change with the tropical ocean and northern extent land for comparison. Note that the temperature scale is on the left and the CO2 scale on the right.

Monday, May 14, 2012

Notes on Stuff

I love messy charts. Showing the short term changes are a reminder of how chaotic things can be. I nice milquetoast smoothed chart is for pansies. Show me the nasty!
This is real nasty. It is the average CO2 monthly change measured at Mauna Loa, the actual monthly change and the deviation from the mean (average) monthly change. Annually, the CO2 measured varies a few parts per million at Mauna Loa. I just took the period from 1979 to 2011 and found the average variation for each month, subtracted the actual value for each month and viola! deviation from the average or mean. Lots of noise, but there are periods of less and more variation.
This compares a portion of the deviation from mean to the TIM TSI solar measurements from SORCE. This is not the solar data I wanted, but the best I have at the moment. If you squint real hard you can see a slight inverse correlation. Lower solar versus greater deviation from mean. This really should be the CO2 deviation from mean versus Solar UV. Why? Because UV creates ozone, ozone reacts with ice crystals and hydroxil (I think that is right) can react with CO2. Real chemistry was never my forte, so I will leave that vague. So what?
I did the same deviation or variation from mean with the UAH mid troposphere temperature data. This chart is the northern extent land and ocean minus the southern extent land and ocean. The extent have a push me pull you thing going on annually. By subtracting the two, it gives a bigger picture of the change in the monthly variation. The break is at 1995 with the trends lead in and out. I use 1995 because I believe that is a climate shift matching the stratospheric shift from cooling to neutral. The UAH mid troposphere data is questionable for the portion around 1983, which would increase the magnitude of the shift if UAH is in error. That shift is I believe due to the Ocean Heat Content (OHC) approaching a pseudo equilibrium for current conditions. Less uptake of heat would create a greater cooling flux which would create greater atmospheric temperature variability. This is all a crazy theory at the moment. It will require a much more serious effort to flesh out, but it does tend to jive with the southern hemisphere temperature reconstructions I have seen, the change in Antarctic sea ice area variation and the change in Artic sea ice variation. There are so many failed climate theories that I am not too enthusiastic about this one, but some pieces are fitting a little better.