Artist Rosten Wu's Vimeo channel has a video title Bridging Time and there is discussion about the Keeling Curve and the site where it all began in Hawaii.

In the video there is a shot of a weather observation station (shown below), and I'm assuming this is Mauna Loa Observatory where these accurate and systematic measurements of CO2 began.

In the foreground there are several gizmos and I was wondering if someone can identify them.

I've included a cropped section, sharpened it a bit, and added annotations A, B, C below the three types of instruments that caught my eye.

Mauna Loa Observatory Gizmos

Mauna Loa Observatory Gizmos


I am going to take a guess here because I have not used these instruments in real life but given the content of this Mauna Loa Observatory I Exploratorium video - fast forward the video to 3:43 and see the yankee name on that instrument.

Then I did a google search on that and got this link - Yankee list of products

So A is a Pyranometer and B is a Ultraviolet Multifilter Rotating Shadowband Radiometer. I am not too sure on C and it probably is a actinometer. You can take a look of that here - Actinometer

The respective data sheets give information on both of those products.

1) Ultraviolet pyranometer

As this AMS glossary definition mentions a pyranometer measures both direct solar radiation(radiation that has not been scattered or absorbed) as well as diffuse sky radiation(radiation that is scattered)

Specifically this ultraviolet pyranometer measures both UV-B and UV-A rays. This link covers the difference btween UV-B and UV-A rays. Specifically UV-A rays penetrate deeper into the skin than UV-B rays.

2) Ultraviolet Multi-Filter Rotating Shadowband Radiometer

This one measures the diffuse and total global irradiance and computes direct irradiance at four or seven narrow bandwidth wavelengths(hence the term multi filter). One can see real time data for sites across the US at this site - UV-B monitoring

3) Originally I thought C was a actinometer but when I look at this image Downwelling SURFRAD instruments I am going to say it is a LICOR PAR sensor(PAR is Photosynthetically active radiation). The reason is because of the instrument inventory provided in this URL - SURFRAD BOULDER CO. If you notice in the NOAA ESRL image there is an instrument that has a shape of a long column(in grey and to the right of the black colored instrument that is actually a MFRSR) that looks very similar to OP's C instrument.

You can now guess why that observatory has these set of instruments. It is at an altitude and that is a good place to study effect of Solar irradiance(less pollution)

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    $\begingroup$ Thanks! Since links break over time, I wonder if it is possible to add a sentence or two in your answer with a short explanation of what those are? $\endgroup$ – uhoh Mar 15 '19 at 15:07
  • $\begingroup$ @uhoh - the wikipedia links are not going to go away are they ? I am not totally comfortable with this answer as this is n't really my area but I will be happy to add a couple of more sentences. $\endgroup$ – gansub Mar 15 '19 at 15:13
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    $\begingroup$ I found this a bit helpful as well, thanks! youtube.com/watch?v=0GYfb3RaPIA $\endgroup$ – uhoh Mar 19 '19 at 14:25
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    $\begingroup$ @uhoh Finally A, B and C identified ! Not this - en.wikipedia.org/wiki/A._B._and_C. $\endgroup$ – gansub Apr 14 '19 at 6:15
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    $\begingroup$ @uhoh Yes thanks. If you actually download this image esrl.noaa.gov/gmd/grad/surfrad/tmtpics/platform1.jpg and enlarge it 200 times or 400 times you will see it is a LICOR PAR sensor. $\endgroup$ – gansub Apr 14 '19 at 9:28

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