Comments on: How to look at the RSS satellite-derived temperature data http://wmbriggs.com/blog/2008/02/09/how-to-look-at-the-rss-satellite-derived-temperature-data/ "All manner of statistical analyses cheerfully undertaken." Fri, 21 Nov 2008 08:38:49 +0000 http://wordpress.org/?v=2.3.3 By: Briggs http://wmbriggs.com/blog/2008/02/09/how-to-look-at-the-rss-satellite-derived-temperature-data/#comment-825 Briggs Mon, 25 Feb 2008 10:16:52 +0000 http://wmbriggs.com/blog/2008/02/09/how-to-look-at-the-rss-satellite-derived-temperature-data/#comment-825 Max, Wavelets don't suffer as much from boundary effects as some other non-parametric function estimation methods, but there is always more uncertainty at the ends that in the middle. Briggs Max,

Wavelets don’t suffer as much from boundary effects as some other non-parametric function estimation methods, but there is always more uncertainty at the ends that in the middle.

Briggs

]]> By: Max Beran http://wmbriggs.com/blog/2008/02/09/how-to-look-at-the-rss-satellite-derived-temperature-data/#comment-810 Max Beran Sun, 24 Feb 2008 21:54:14 +0000 http://wmbriggs.com/blog/2008/02/09/how-to-look-at-the-rss-satellite-derived-temperature-data/#comment-810 Can you really trust those wavelets near the extremities? Look at the preponderance of positive departures in the most recent data from the two NH series. Can you really trust those wavelets near the extremities? Look at the preponderance of positive departures in the most recent data from the two NH series.

]]> By: Mike Rankin http://wmbriggs.com/blog/2008/02/09/how-to-look-at-the-rss-satellite-derived-temperature-data/#comment-690 Mike Rankin Wed, 20 Feb 2008 04:36:29 +0000 http://wmbriggs.com/blog/2008/02/09/how-to-look-at-the-rss-satellite-derived-temperature-data/#comment-690 Re: Analysis of temperature data. Anthony Watts has been testing variations of Stevenson screens for the measurement of ambient air temperature. His blog at http://wattsupwiththat.wordpress.com/2008/01/14/a-typical-day-in-the-stevenson-screen-paint-test/#com shows some of his recent findings. Anthony has given us glimpses but not proceded to complete his analysis. I am a hobbyist in statistics and have my own thoughts. How would you analyze this data? Please contact Anthony if more information is required. My own impression is that spectral analysis would be suitable. Or perhaps some model using phase shift and amplitude multiple. Re: Analysis of temperature data.

Anthony Watts has been testing variations of Stevenson screens for the measurement of ambient air temperature. His blog at

http://wattsupwiththat.wordpress.com/2008/01/14/a-typical-day-in-the-stevenson-screen-paint-test/#com

shows some of his recent findings. Anthony has given us glimpses but not proceded to complete his analysis. I am a hobbyist in statistics and have my own thoughts. How would you analyze this data? Please contact Anthony if more information is required. My own impression is that spectral analysis would be suitable. Or perhaps some model using phase shift and amplitude multiple.

]]> By: Steve Hempell http://wmbriggs.com/blog/2008/02/09/how-to-look-at-the-rss-satellite-derived-temperature-data/#comment-478 Steve Hempell Wed, 13 Feb 2008 00:31:09 +0000 http://wmbriggs.com/blog/2008/02/09/how-to-look-at-the-rss-satellite-derived-temperature-data/#comment-478 Matt Is this: http://www.climateaudit.org/?p=2720#comments related to what you were describing in the 3rd graph (on smoothing)? Matt

Is this:

http://www.climateaudit.org/?p=2720#comments

related to what you were describing in the 3rd graph (on smoothing)?

]]> By: G Robin Edwards http://wmbriggs.com/blog/2008/02/09/how-to-look-at-the-rss-satellite-derived-temperature-data/#comment-460 G Robin Edwards Mon, 11 Feb 2008 19:35:02 +0000 http://wmbriggs.com/blog/2008/02/09/how-to-look-at-the-rss-satellite-derived-temperature-data/#comment-460 Dr Briggs, I also look carefully at climate data, and have received direct from Prof Spencer some of his data. What I would really like to get hold of are the actual numbers that you used to prepare your really illuminating and recent analyses. I use totally different techniques and it might be very interesting to compare out conclusions. If you cold post a url I'd be most grateful. Dr Briggs, I also look carefully at climate data, and have received direct from Prof Spencer some of his data. What I would really like to get hold of are the actual numbers that you used to prepare your really illuminating and recent analyses. I use totally different techniques and it might be very interesting to compare out conclusions. If you cold post a url I’d be most grateful.

]]> By: Andrew http://wmbriggs.com/blog/2008/02/09/how-to-look-at-the-rss-satellite-derived-temperature-data/#comment-431 Andrew Sun, 10 Feb 2008 22:45:07 +0000 http://wmbriggs.com/blog/2008/02/09/how-to-look-at-the-rss-satellite-derived-temperature-data/#comment-431 Yes, thank you, I understand now. Yes, thank you, I understand now.

]]> By: thomas lavin http://wmbriggs.com/blog/2008/02/09/how-to-look-at-the-rss-satellite-derived-temperature-data/#comment-430 thomas lavin Sun, 10 Feb 2008 22:40:39 +0000 http://wmbriggs.com/blog/2008/02/09/how-to-look-at-the-rss-satellite-derived-temperature-data/#comment-430 http://www.flickr.com/photos/23668657@N07/ try this please. sorry for the other link. please use the sea data in addition to the land data if you want to recreate these Note that doing this exercise , baseline 1881-1950, and using comparator years as 1975-1980 or there abouts provides maps and latitude plots which are frankly cooling. please also note that the maps and plots are not corrected for surface area and therefore might mislead an observer to think that a .5 degree rise at latitude 85 is as significant as a .5 degree rise at the equator in terms of amount of warmed surface. I think you have to correct by 1-sin (lat) to get an idea of area. my kudos to nasa for making the data available. you can download the text data file also. The raw giss data can be inspected station by station also http://data.giss.nasa.gov/gistemp/station_data/ It is very instructive to look at the raw data. pick an area in the middle of the usa and start pulling up graphs station by station rural and otherwise. I did this to a randomly selected area or two and clicked through over 20 stations. Its a good source of data to study http://www.flickr.com/photos/23668657@N07/

try this please. sorry for the other link.

please use the sea data in addition to the land data if you want to recreate these

Note that doing this exercise , baseline 1881-1950, and using comparator years as 1975-1980 or there abouts provides maps and latitude plots which are frankly cooling.

please also note that the maps and plots are not corrected for surface area and therefore might mislead an observer to think that a .5 degree rise at latitude 85 is as significant as a .5 degree rise at the equator in terms of amount of warmed surface. I think you have to correct by 1-sin (lat) to get an idea of area.

my kudos to nasa for making the data available. you can download the text data file also.

The raw giss data can be inspected station by station also

http://data.giss.nasa.gov/gistemp/station_data/

It is very instructive to look at the raw data. pick an area in the middle of the usa and start pulling up graphs station by station rural and otherwise. I did this to a randomly selected area or two and clicked through over 20 stations. Its a good source of data to study

]]> By: Steven mosher http://wmbriggs.com/blog/2008/02/09/how-to-look-at-the-rss-satellite-derived-temperature-data/#comment-428 Steven mosher Sun, 10 Feb 2008 19:22:03 +0000 http://wmbriggs.com/blog/2008/02/09/how-to-look-at-the-rss-satellite-derived-temperature-data/#comment-428 might be fun to look at artic sea ice extent and the upper latitude temps.....over time might be fun to look at artic sea ice extent and the upper latitude temps…..over time

]]> By: Administrator http://wmbriggs.com/blog/2008/02/09/how-to-look-at-the-rss-satellite-derived-temperature-data/#comment-427 Administrator Sun, 10 Feb 2008 19:11:47 +0000 http://wmbriggs.com/blog/2008/02/09/how-to-look-at-the-rss-satellite-derived-temperature-data/#comment-427 Andrew, It's because the running mean, to estimate a value at some point t, only uses data prior to time t, when more modern methods of smoothing use data on both sides of t. Because of this, it can make sense to use running means as a crude forecast tool, because, obviously, you only have data up to time t to predict future data. But running means are horrible smoothing, function estimating tools; their use is, unfortunately, ubiquitous. I wrote about this earlier <a href="http://wmbriggs.com/blog/2007/12/30/hurricanes-have-not-increased-misuse-of-running-means/">here</a> and <a href="http://wmbriggs.com/blog/2008/01/23/ams-conference-report-day-3/">here</a> : Hope that makes sense. Briggs Andrew,

It’s because the running mean, to estimate a value at some point t, only uses data prior to time t, when more modern methods of smoothing use data on both sides of t. Because of this, it can make sense to use running means as a crude forecast tool, because, obviously, you only have data up to time t to predict future data. But running means are horrible smoothing, function estimating tools; their use is, unfortunately, ubiquitous.

I wrote about this earlier here and here :

Hope that makes sense.

Briggs

]]> By: Andrew http://wmbriggs.com/blog/2008/02/09/how-to-look-at-the-rss-satellite-derived-temperature-data/#comment-426 Andrew Sun, 10 Feb 2008 19:06:30 +0000 http://wmbriggs.com/blog/2008/02/09/how-to-look-at-the-rss-satellite-derived-temperature-data/#comment-426 I've never understood the phenomenon whereby a moving average always seems to shift data forward in time. Why is this? Very interesting post, by the way. I’ve never understood the phenomenon whereby a moving average always seems to shift data forward in time. Why is this?
Very interesting post, by the way.

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