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Inferring cloud cover from VP2 solar data

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miraculon:
I saw this fancy cloud cover instrument, which is more expensive than I can justify: https://diffractionlimited.com/product/boltwood-cloud-sensor-ii/

Just watching my solar plots on a daily basis, got me to wondering if there was some way to compare a "clear sky" day based on historical data and determine roughly the cloud cover. I am thinking something very basic like "clear", "partly cloudy" and "overcast".

For example, this recent chart shows a clear day the first day, followed by partly cloudy days.

Maybe the database work it too complex. This is beyond my programming skills, but I was wondering if anyone had attempted something like this.

Greg H.

Bushman:
Stick your head out the window and look.  :)   Seriously though check this for info:  http://web.mit.edu/parmstr/Public/NRCan/rp418.pdf

pfletch101:

--- Quote from: miraculon on November 01, 2018, 11:55:05 AM ---I saw this fancy cloud cover instrument, which is more expensive than I can justify: https://diffractionlimited.com/product/boltwood-cloud-sensor-ii/

Just watching my solar plots on a daily basis, got me to wondering if there was some way to compare a "clear sky" day based on historical data and determine roughly the cloud cover. I am thinking something very basic like "clear", "partly cloudy" and "overcast".

For example, this recent chart shows a clear day the first day, followed by partly cloudy days.

Maybe the database work it too complex. This is beyond my programming skills, but I was wondering if anyone had attempted something like this.

Greg H.

--- End quote ---
It's not really a database issue. Insolation and cloud cover don't have a terribly linear relationship. You can have reasonably good insolation with 100% coverage by fairly thin cloud, and you can have normal measured insolation for a clear sky despite thick cloud cover confined to the part of the sky that doesn't contain the sun (and, of course, vice versa).

Michaelpt:

--- Quote from: miraculon on November 01, 2018, 11:55:05 AM ---I saw this fancy cloud cover instrument, which is more expensive than I can justify: https://diffractionlimited.com/product/boltwood-cloud-sensor-ii/

Just watching my solar plots on a daily basis, got me to wondering if there was some way to compare a "clear sky" day based on historical data and determine roughly the cloud cover. I am thinking something very basic like "clear", "partly cloudy" and "overcast".

For example, this recent chart shows a clear day the first day, followed by partly cloudy days.

Maybe the database work it too complex. This is beyond my programming skills, but I was wondering if anyone had attempted something like this.

Greg H.

--- End quote ---


You could try making one, have a look at http://www.weather-above.com/howirsky.html
Data is on
http://www.weather-above.com/video.html

I have not been to good health problems, hopefully next year will update website with more information,

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