Improved determination of "sunny", "cloudy&qu

Brian,

The indications of “sunny”, “cloudy”, etc. provided by WD don’t always square with observation. For example, it’s been sunny practically all day today, but WD shows only 2.5 hours of sunshine. This is because the sun is pretty low in the sky these day, even at noon. Similarly, it will be bridght sunshine at sunrise and sunset, but WD indicates “cloudy.” This is because the sun is low in the sky at these times.

Currently, the solar sensor setup in WD invites the user to input an abitrary solar reading as 100% and arbitrary percentages as thresholds for “sunny”, “cloudy”, etc. Unfortunately, this way of determining “sunny”, “cloudy”, etc. doesn’t take into account the diurnal and annual variations in the altitude of the sun. In reality, the 100% solar reading depends on the solar altitude.

Does the sunrise/sunset calculation module of WD have the ability to calculate solar altitude at the weather station latitude at regular intervals throughout the day? Or would it be possible to add such a calculation? If so, it would be a simple matter to multiply a global solar maximum by the sine (I think) of the solar altitude to get an instantaneous, local, automatic 100% solar reading. This 100% could then be used with user-entered percentages to determine “sunny”, “cloudy”, etc.

Is this feasible, Brian. If so, it would be a nice feature.

Regards

Ian

yes, as i already have a calculation for maximum solar intensity at a given time of the day…(for your lat/long),which is now used for the evapotranspiration rate…
so i can use that to fine tune it

Sounds like a plan, Brian.

I’ll be interested to see what you come up with.

Thanks,

Ian

Brian,

Any further thoughts on this?

Ian

it has been on my agenda…
but i was wanting to get my own solar sensor regoing after a lightning strike…
i have now, so I can look into this

Thanks, Brian (and a Happy New Year)

Ian