Strange wind speed values


I recently downloaded the PSM data for a location in Bolivia (the NSRDB point was at -17.79,-63.18) through the online viewer. When I was checking the data, the solar insolation values made sense and so did the wind directional information, but I think there is something wrong with the wind speed numbers. The data I downloaded shows average wind speeds of well below 1 m/s, with the maximum value over the 18 years of data being only 1.4 m/s! According to the data stored in the MERRA database, the average speeds should be more like 5-8 m/s.

Perhaps there was some bug in the wind speed data or perhaps an incorrect unit conversion? Has anyone else seen this sort of issue before?

Dear Ryan,

Thank you for bringing this into our attention. We are investigating this but could you please tell us what height of wind speed you were looking for in the actual MERRA data.

Best Regards,

Aron Habte

I was viewing it through the interface at NASA's POWER website ( which gives the 10m wind speed.

Dear Ryan,

The wind speed data we have in the NSRDB is @ 2m. Please use the 2m MERRA to compare your data.


Aron Habte

Hi Aron,

The label of the wind speed attribute used in the API is wind_speed_10m_nwp (as documented at and, which I took to imply that the height is 10m. Could you share any documentation on how these wind numbers are derived, and do you have a reference specifying the wind height as 2m other than this comment?

Thanks very much,

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