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US climate change at the county level

US County century-scale climate change

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POSTED BY: John Shonder
22 Replies

Recently I tried updating this map using the current data file ("climdiv-tmpccy-v1.0.0-20220804.txt") and it didn't work. I found that NOAA is now including data from Alaska in the master file, whereas previously the Alaskan data was in a separate file. I reworked the notebook to account for this change. You will still have to change the statement beginning cdata = SemanticImport[ to reference the directory where you have placed the file of historic temperatures.

The updated notebook, and the map, are attached.US Climate Change

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POSTED BY: John Shonder

Thank you, I enjoyed your videos. I think every school in the country should be doing a lesson plan like that.

POSTED BY: John Shonder
Posted 5 years ago

Hare's the link to the two follow on projects that I did with my kids. The first was my 7th graders idea to look at percent change rather than absolute change. The 2nd was my 9th graders idea to see how we could make predictions (which I modified to be a project about linear and quadratic approximations to the data).

https://mikesmathpage.wordpress.com/2019/06/23/follow-up-2-to-john-shonders-us-weather-data-visulaization/

Thanks so much, John, for sharing your work. Using it with my kids has been really fun. I'm really happy that this sort of data analysis can be made accessible to middle and high school kids.

POSTED BY: Mike Lawler
Posted 5 years ago

John -

I used your post for a project with my kids this morning. Thanks for sharing this amazing work - they loved it and had a few ideas that they'd like to explore a bit more. Can't wait to work on these ideas with them. Here's what we did:

https://mikesmathpage.wordpress.com/2019/06/16/using-john-shonders-amazing-us-temperature-visualization-with-kids/

POSTED BY: Mike Lawler
Posted 5 years ago

Great way to get the kids interested. I did much the same as you but experimented with different start years. TBP.
BTW the missing county is entirely an Indian reservation with no county seat. (I wonder why kriging was not used).

POSTED BY: Douglas Kubler

Mike, how nice to know you were able to use the code and data to teach your children. That's why I posted it: hoping people would extend the analysis, try out different smoothing techniques, use different starting and ending points, etc. I watched your videos and it sounds like your boys have some good ideas. I'll be interested to see what they come up with. Happy Father's Day.

POSTED BY: John Shonder
Posted 5 years ago

I decided to publish my changes. I separated the temperature ranges at 0 so there's no doubt as to the direction of change. Also the start date is 20 years later to see how the trend changes. enter image description here

POSTED BY: Douglas Kubler

Very interesting Doug! In later versions of this map I too decided to use shades of blue for negative changes. It makes sense visually. You also see that the starting point makes a difference too. The map at the top of this page shows temperature changes between 1991 and 2012 compared to the average temperature between 1901 and 1960.

POSTED BY: John Shonder
Posted 5 years ago

Starting point makes a difference - 1991 is a unique starting point. Mt. Pinatubo eruption.

Nearly 20 million tons of sulfur dioxide were injected into the stratosphere in Pinatubo's 1991 eruptions, and dispersal of this gas cloud around the world caused global temperatures to drop temporarily (1991 through 1993) by about 1°F (0.5°C). (https://pubs.usgs.gov/fs/1997/fs113-97/)

I'll attach a run of your 10-year moving averages 1991-2012, not as year-specific but interesting. (Is there a way to embed the legend in the chart?)

enter image description here

!legend for climate by counties][1]

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POSTED BY: Douglas Kubler
Posted 6 years ago

Great chart with potential for display of any year span.

POSTED BY: Douglas Kubler

The question I thought someone was going to ask is where did they get temperature data for counties that didnÂ’t even exist at the time. Arizona for example didnÂ’t become a state until 1912 and yet there are the average monthly temperatures for each of its current counties back to 1895. The answer is through kriging.

POSTED BY: John Shonder

John, the documentation's state code reference was the key for me. Thank you again for the suggestion.

-Ed

POSTED BY: Ed Forrester

Thank you. Must be my error in calculating the FIPS.

-Ed

POSTED BY: Ed Forrester

Ed, you have to read the documentation for that file. As I said above, it does not contain the FIPS code, but a number that can be transformed into a FIPS code. And I showed how to do it.

POSTED BY: John Shonder

John, I may be mistaken in decoding the file, but I believe the file shows about 17 county entries for Michigan and it has 83. For Arizona, the state code is 04 and has 15 counties. The file shows 58 counties being reported for 04. FYI. Thanks for the information as well as your analysis. Very Interesting.

POSTED BY: Ed Forrester

Mads, that is a great question. All of the data I used are online at the site I referenced, and it would be easy to modify my code to get a map of the standard deviation by county.

POSTED BY: John Shonder

Excellent analysis! A quick question, what was the standard deviation in temperature measurements? I am asking that because some Delta T are small and I wonder to what extend we can interpret them as a meaningful shift in T?

POSTED BY: Mohammad Bahrami

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POSTED BY: EDITORIAL BOARD

Hi John, and thanks for sharing - very educational. One thing I don't fully understand (and maybe you can explain it a bit?) is how you calculated the values for the legend.

E.g. when I'm retracing your steps, I don't see any negative values in qq:

Min[qq]
0.134336

and

zz
{0.74857, 1.3628, 1.97704, 2.59127, 3.20551, 3.81974, 4.43397, \
5.04821, 5.66244}

What am I missing?

POSTED BY: Victor Kryukov

My mistake. I originally used a moving average of 10 years for the smoothing, and then changed it to an exponential average. The values in the legend correspond to the moving average case. Looking at both figures, there really is not much of a difference. This is a problem when using a bespoke legend as I did.

I'm sure it would be possible to generate the legend automatically with the correct limits -- and perhaps someone will be interested enough to show us how to do that -- but for now I went back and edited my original post to correct everything. The figure and the file now use the moving average.

POSTED BY: John Shonder

Hi John, Thanks for sharing. It seems a great code. But unfortunately I don't have access to the website and data (see screenshot below). Please can you support me with the data? Your support will be highly appreciated ! Best Regards,....Jos

enter image description here

POSTED BY: Jos Klaps
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