Enhanced UAH Channel 5 Temperature Anomaly Trend Chart: Update 1

This post discusses my updated and enhanced UAH Channel 5 daily trend chart. Updated 3/29/11

Update 1: 3/29/11

Since I have received a number of comments and questions about this post, I am updating it to address these comments and improve the chart.

I plot the Channel 5 data because it is available in rear real time so that readers can get a sense for how the monthly global temperature anomaly is shaping up. However, the comments tell me that there is some confusion about Channel 5 and how it compares to the UAH TLT data.

Lucia at The Blackboard has a detailed discussion of UAH TLT and Channel 5 here. Bob Illis has an interesting chart that shows the differences between UAH TLT and Channel 5 here.

Dr. Roy Spencer discussed tracking daily global temperature anomalies here.

I have revised my chart to show both the UAH TLT 5.4 and Channel 5 monthly trends as well as the daily Channel 5 data for the current month.


Original Post

I’ve added this UAH Channel 5 trend chart to my sidebar:  (Click to enlarge)

I originally added a daily UAH Channel 5 chart in my May 9,2010 post. UAH changed their file format over the summer so I had to revise the chart.

This new R based version has several features that help track daily temperature anomalies:

  • Shows monthly average values for available data
  • Shows current month-to-date average and highlights previous year monthly averages so that readers can assess the current month with respect to the same month in previous years
  • Shows daily values for current month in figure-inside-figure
  • Shows maximum day of year values for each day in current month

I update this chart daily in the Climate Trends Sidebar so you can quickly see how the UAH satellite based global temperature anomaly is developing over the month. Please note that UAH’s Channel 5 values are adjusted by UAH at the end of month so that it is only an indication of the actual monthly anomaly.

18 responses to “Enhanced UAH Channel 5 Temperature Anomaly Trend Chart: Update 1

  1. HI kelly

    I probably owe you an apology remembering that I sent that email requesting 1979 on data. Which you duly put up. I think my point was not to eliminate the aqua satellite data stand alone graph on my basis that it shows no warming. In my view the second does not either, especially with current trends.

    Anyway good luck with your endeavours and yes I will refer to your site graph to show no warming if I may? (BTW my Father was a WMO meteorologist/physicist published 3 papers in Nature and di not believe in glowal warming in 2000.


  2. I can probably help out on the daily AMSU versus actual UAH temps.

    There is an adjustment made to the reported AMSU temps of anywhere from -0.1C to +0.3C and the average is +0.123C as shown in this graphic covering the daily numbers from 2009 to Feb. 2011.

    I’ve got the daily Global, SH, NH and Tropics temps from 2010 to March 9, 2011 like this. Anomaly on march 9, 2011: -0.243C

    The actual daily UAH temps in the newest 5.4 version in the order of Global, SH, NH, Tropics are here. (Divide by 1000 for Anomaly degrees C).


  3. Hello Kelly,

    THANKS! So, now i calculate the same values.

    Also am searching for the average values which Roy Spencer use for the calculation of the anomalies in the final UAH Product. Do you know them ?


    • piet:

      Glad to see our calculations match.

      I don’t have any information on Roy Spencer’s “average values” for the UAH “final product”.

      I’ll be interested in anything you find out. Can you keep me posted on your work?


  4. Hey Kelly,
    there is a difference between the data source and your chart.
    I calculate for 2011-03-07

    absolute Temp for this day: 252,125K
    Monthly mean for march: 252,4463871 K
    [sum( average per march day)/31]
    2011-03-07: -0,321K !
    ( your data is 0,307K )
    current MTD: -0,277K
    (your data is -0,223K )

    there is a little difference in my calculation.

    Do you know the fault ?


    • piet

      Great question, thanks. I’m glad to see you are checking my calculations. I had to recheck them myself.

      UAH provides 14 columns ( numbers 0-13) in their data file: link

      Col 13 (UAH number) gives the average for each day of year. To calculate the current day-of-year anomaly, I use the current value in col 10 minus value in col 13.

      So for 3/7/11:

      col 10 = 252.125
      col 13 = 252.432
      anom = – 0.307

      You are using March averages for your anomaly calculation.

      They are close so it is a minor difference. Since I had the data, I chose to use the daily values.


  5. Dear Kelly,

    to add to the confusion, your graph version UAH 5.4 is from the Aqua satellite (the newest one), and so is Dr. Spencer’s monthly graph. On the discover website you will currently find that it also shows daily AMSU-AQUA data (until 2010 it used to show the old NOAA15 AMSU data). The daily data you (and the discover website) use is then probably currently based on the AQUA data, before it has been calibrated/adjusted to the monthly data of Dr. Spencers monthly graph and your monthly UAH 5.4 graph. I’m surprised the monthly data differs so much from the daily (uncalibrated) data, but this has been noted before.

    • Hi Arjan,

      Here are the difference between the 5.3 and 5.4 Dataset

      Update 8 Dec 2010 *************************

      Preliminary runs show that the new mean annual cycle will be about 0.1 C warmer
      each month for the global averages, meaning all monthly anomalies will appear to
      decrease by about 0.1 when the new 30-year base period is used (see below).

      Here are the preliminary differences (old annual cycle v5.3 minus
      new annual cycle (v5.4).)
      The final anomalies will be out next month when Dec is calculated.

      TLT annual cycle v5.3 minus v5.4

      1 -0.106 -0.185 -0.026 -0.047
      2 -0.093 -0.167 -0.019 -0.033
      3 -0.099 -0.186 -0.013 -0.006
      4 -0.102 -0.193 -0.010 0.000
      5 -0.079 -0.134 -0.026 -0.003
      6 -0.052 -0.067 -0.036 0.008
      7 -0.070 -0.077 -0.063 -0.050
      8 -0.069 -0.096 -0.043 -0.043
      9 -0.125 -0.146 -0.104 -0.049
      10 -0.119 -0.113 -0.127 -0.050
      11 -0.109 -0.139 -0.079 -0.048
      12 -0.075 -0.129 -0.021 -0.068

      So, for example, here is the old set of 2009 anomalies (v5.3) and the
      new set (v5.4)

      2009 1 0.251 0.472 0.030 -0.068
      2009 2 0.247 0.565 -0.071 -0.045
      2009 3 0.191 0.324 0.058 -0.159
      2009 4 0.162 0.315 0.008 0.012
      2009 5 0.139 0.161 0.118 -0.059
      2009 6 0.041 -0.021 0.103 0.105
      2009 7 0.429 0.190 0.668 0.506
      2009 8 0.242 0.236 0.248 0.406
      2009 9 0.505 0.597 0.413 0.594
      2009 10 0.362 0.332 0.393 0.383
      2009 11 0.498 0.453 0.543 0.479
      2009 12 0.284 0.358 0.211 0.506

      2009 1 0.145 0.287 0.004 -0.115
      2009 2 0.154 0.398 -0.090 -0.078
      2009 3 0.092 0.138 0.045 -0.165
      2009 4 0.060 0.122 -0.002 0.012
      2009 5 0.060 0.027 0.092 -0.062
      2009 6 -0.011 -0.088 0.067 0.113
      2009 7 0.359 0.113 0.605 0.456
      2009 8 0.173 0.140 0.205 0.363
      2009 9 0.380 0.451 0.309 0.545
      2009 10 0.243 0.219 0.266 0.333
      2009 11 0.389 0.314 0.464 0.431
      2009 12 0.209 0.229 0.190 0.438

      The Base periods are:
      5.4: 1981 – 2010
      5.3: 1979 – 1998

      So Kelly use the base periode from 1979-1998 and this is the same base as version 5.3 from UAH.

      And I am wondering about the difference between the Version5.3 and the Anomalies in Kellys Aqua Channel.
      For my understanding the anomalies are not equal because:
      – Kelly use only the dataset from the aqua channel:

      But Roy Spencer explained:

      This web page should be used as only a rough guide ( Kellys chart ), because there are some data adjustments made before we officially post the UAH monthly updated data. The biggest adjustment is the fact that we don’t even use NOAA-15 right now…we are using the AMSU data from NASA’s Aqua satellite in the final UAH product.”

      He said that he use although the Aqua Satellite in the final produkt. So why there are differences in the anomalies ??


  6. Ah, the version 5.4 graph is the graph I’m familiar with. I’m surprised to learn the differences are so large, but indeed that is not your fault. I’m sorry for initially suggesting otherwise. Keep up the good work!

  7. Thanks for this site. The data is very well presented and clear. Would it be possible to include another of graph AMSU ch 5 trend chart from 1979? when it started? thanks

  8. Dear Kelly,

    Okay, I’m surprised Dr. Spencer did not update the daily values. I’ve noticed some rather large differences between your graph and Spencer’s. Temperatures of the El Nino in 2009/2010 are much lower than in Spencer’s graph, but Dr. Spencer uses a higher (30 year) baseline, so that his anomalies should be approximately 0.1 C lower than yours (the daily files are 20 year = 1979 – 1999 averages?). Also your current monthly anomalies seem to be 0.1 low compared to Spencer’s graph, while using a warmer baseline. Sorry if I’m confused, but I’m just wondering, as I’ve seen more problems with the baseline change of UAH.

    • Arjan

      Please read Dr Spencer’s discussion of daily tracking of Chanel 5 here .

      Dr Spencer explains that the the daily Channel 5 data is only a rough guide for how a month is shaping up.

      This web page should be used as only a rough guide, because there are some data adjustments made before we officially post the UAH monthly updated data. (I post a plot of those data here.) The biggest adjustment is the fact that we don’t even use NOAA-15 right now…we are using the AMSU data from NASA’s Aqua satellite in the final UAH product.

  9. Yes, so the curves shown are currently incorrect and need updating to account for the new baseline! (Great site btw!)

  10. Hello,

    i like to know from when is the baseline periode.
    Actual UAH use a 30j baseline 81-10. Here is a 20j baseline .


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