Wind Speed Multiplier

[ParadisBlanc]

Hello all,


would someone be kind enough to point me to some reference that would explain to a novice guy what is the reason-to-be and the purpose of the "wind speed multiplier"?


Thank you so much.

[Felix]

I'll try to find you a more precise reference from the UK MET Office when I have more time since the WeatherCat developer resides across the pond (alternatively peek at WeatherCat manual page 164) but take a look at the following Weather Forum thread which is dated but still gives you the general idea of why it might be helpful (depending upon your particular usage of the wind data) to apply a correction factor if your anemometer is less than 10 meters high:

http://www.wxforum.net/index.php?topic=2753.5;imode

[ParadisBlanc]

Hello Felix and thank you for the pointer.
Wind is like any other fluid flowing in a container (water in pipe, for example), it goes faster away from the container (water goes faster in the center of the pipe).

Thus if I understand properly, and please correct me if I'm wrong:

• the anemometer can be placed at any height the user wish, to measure the wind speed according to its need
• the reading of the anemometer is the true wind speed measured at the actual height the device is physically set
• there exists a general/common/official rule for the reference height = 10m
• if the device is not set at this height, a scaling factor shall be applied (>1 if under 10m, <1 if above 10m)
• the purpose of scaling the measurement, is to have a "worldwide" database of Wind Speed measurements @10m

In other words, if I want to share my Wind Speed measurements with the community, I have to scale it accordingly (to align with the reference of 10m height).
I have not seen it in WC, but is there a way to keep the Wind Speed measurements in my local database as they are measured (2m, for my own purpose) and transmit to the community with the 10m re-scaling (for worldwide purpose)?