Kriging of Hadcrut4.5 data

Here  is the result of a Gaussian ‘kriging’ of  Hadcrut4.5 temperature anomalies for February 2016. This is essentially what Cowtan & Way do.

Kriged result for February 2016

Hadcrut4.5 measured anomaly data (no kriging)

This clearly shows why the global average of the kriged data gives larger values than Hadcrut4.5 when anomalies at high latitudes are warmer.

However I still prefer Hadcrut4.5 because it makes less assumptions, which is especially important for early years.

kriged values

Raw H4 values

One interesting possibility of kriging is that it can also handle irregular grids. This means that you don’t even need to average the data in grid cells first. I might even try this, if I find the time. I suspect this is more or less exactly what Berkeley Earth does.

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13 Responses to Kriging of Hadcrut4.5 data

  1. The answer to missing stations into data infilling – it’s putting in stations where they are missing.

  2. A C Osborn says:

    The first & second globes appear to bear absolutely no relationship to the real world.
    I suggest you spend some time going through the reports of record breaking “extreme weather” in Eastern Europe and Russia at IceAgeNow.
    Australia is also split into a Colder than normal and a Hotter than normal place not shown in those globes either.

    • Clive Best says:

      I am not defending ‘Kriging’. I am just seeing where it takes us by following the same procedure as Cowtan & Way. In reality the monthly variation in ‘warming’ can be very large. Hot spots appear in Winter and disappear in Summer. Warming is mostly due to an increase in minimum temperature (winter and nightime) rather than an increase in maximum temperatures. You don’t see this on anomaly plots. Australia goes through decade long cycles of drought and cycles of rain.

  3. Hans Erren says:

    Hi clive can you please also show the kriging standard error map for feb 2016? I surmise it will go through the roof at the arctic.

  4. David Walker says:

    Kriging = Making Stuff Up.
    Totally dishonest.

  5. Clive, I have figured it out. Eureka! Everyday an experiment occurs that we can measure all the variables of temperature, pressure, and humidity to find the contribution that CO2 provides to the amount of heat being trapped in the environment. If you take the average global temp of 14.8 deg. C and the black body temp of -18 deg. C this is the amount of heat that the greenhouse gases trap. Water is typically between 10x more concentrated to 30x more concentrated than CO2. From the absorption spectrum of water vapor vs. CO2, water vapor absorbs 2.8x more heat. From a diffusion rate, water vapor beats CO2 by 1.56x. This gives a total heat absorption coefficient for water vapor of 131. If we take the difference between average global temperature and blackbody temperature, we get Take 32.8 degrees. Now divide this temperature difference by the coefficient and that is the temperature contribution by CO2. It is always 32.8 deg. C difference, at least in mid latitudes and the equator, no matter what the daily high or low. Since temperature is indicative of the average kinetic energy of the molecules in a substance, we can use this temperature contribution by CO2 to the daily high and low, and relate its total contribution to the amount of energy captured by CO2 ,near ground level. We can use the lapse rate to extrapolate the upper level values. Depending on the absolute humidity, CO2 contributes 0.25 degrees C to 0.76 deg. Celsius. I have actually done a calculation for Las Vegas, NV on June, 27 2011, on a record low humidity (4%, but actually was 1% briefly) day and I got an answer of 1.0 deg. C contribution for the CO2 for the high that day. I based the absolute humidity calculation of the 4% relative humidity figure at 107 deg F.

    • Clive Best says:

      Another place to look for the CO2 effect is in dry deserts without water vapour. Heat loss at night via IR cooling is high so the diurnal temperature difference night/day is very high. If CO2 increase diminished the heat loss at night there should be some measurable increase in minimum temperatures. http://clivebest.com/blog/?p=3015

  6. I am too spoiled on the edit feature when I hit submit and then capture mistakes. I meant to say that the difference between blackbody temperature and average global temperature is 32.8 degrees Celsius. Also this difference will be calculated between the “would be blackbody high” or “would be blackbody low” and the daily high or daily low. If we divide this difference of 32.8 deg C by the water vapor to CO2 heating coefficient, we get 0.25 to 0.76 deg. C. This range is due to the variable water vapor concentration in ppmv.

  7. Nick Stokes says:

    Clive,
    “This means that you don’t even need to average the data in grid cells first. I might even try this, if I find the time.”
    The task of global averaging is numerical spatial integration, and this has been around for a long time. Gridding is just one not very good way of doing it. I have used better methods, which I tested here. My main one is the standard finite element method, using an irregular triangular mesh (examples shown here). Almost as good is the fitting of spherical harmonics by least squares, and integrating the fit. That is completely grid- or mesh- free.

    • Clive Best says:

      Nick,

      I spent 2 solid days trying to use kriging to try and merge the 7300 GHCN V3 stations with HADSST3 ‘measurements’ in order to get a monthly global average. It is rather complicated and very error prone. Having eventually debugged the code the results are disappointing and look washed out. So I just changed to first using an irregular triangulation of measurements before averaging and the results are much better !

      Looks like you are correct!

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