Howdy JG, Stu, and WeatherCat fans,
Today was much sunnier than yesterday, but the Solar Radiation "Gauge" only shows 782. The weather almanac shows that today had nearly an hour more sunlight than yesterday. Does that make sense?
The solar radiation "gauge" is actually a measure of the power of the photons striking the sensor. It is measured in Watts/m
2. So that measurement is how much power is available say for a solar panel to convert into electricity. It is
not the same as say how warm the sun feels or other things you might associate with the sun's effect on your body or the land.
Does Solar Radiation have anything to do with UV? It seems impossible that there were 100 less units today than the day before as there was more sun today, less clouds, etc.
This isn't the same as either solar radiation or things like the sun's warmth. It is measure of the photons in the Ultra-Violet specifically. Ultra-Violet light can be effected by atmospheric conditions that aren't immediately viable. So for example water vapor could absorb UV but not appear in the sky as clouds. Alternatively a day with less total solar radiation would have a stronger UV effect because the air is particularly transparent. That's why Davis provides two sensors. You can't reliably predict one value from the other.
Cheers, Edouard