Dear JG and WeatherCat station design consultants,
My weather station (Vantage Pro 2) at my Maine house is in a woodsy area that is good in that it gets no heat from the house or road, gets relatively accurate wind readings, but the solar readings are completely inaccurate.
I noticed that I can move the Solar and UV sensors up to 125' - would their placement in a more typically sunny location translate into more accurate ET and Sunshine Hour readings?
I suspect you can answer your question better than we can. It depends on the height of the trees nearby. If that's enough to get above the trees, of course that will solve your problem.
Something to keep in mind is that evapotranspiration is a relative number that should represent the amount of solar radiation and wind that the plants are exactly experiencing. The
Penman?Monteith equation that is incorporated into the Vantage Pro 2 is an estimate of evapotranspiration for grasses. So it isn't a number that applies to the tree-tops.
However, there is no doubt that if you get your solar radiation sensor above the trees, then you'll get more reasonable values for the number of sunshine hours.
I suppose you need to ask yourself what value you get out of either parameter. Sunshine hours have a practical use. Evapotranspiration can be useful in gardening, but only if the sensors experience similar conditions to the plants being watered. If you aren't gardening - no worries!
Cheers, Edouard
P.S. You can run two different versions of the
Blaney?Criddle equation on WeatherCat. There is a dedicated AppleScript and an AppleScript synthetic channel. The Blaney?Criddle equation isn't nearly as accurate in locations with high humidity, but given that you cannot easily get good Penman?Monteith estimates, perhaps a second estimate could be useful to you.