Earthdata Forum

Hello everyone,

I would like to know if it is possible to obtain the maximum and minimum daily total solar irradiance (W/m2) incident (direct plus diffuse) on a horizontal plane from the Power Project database data. I saw that the "All Sky Surface Shortwave Downward Irradiance" parameter provides the total solar irradiance on a horizontal plane (W/m2) on an hourly and daily basis for the Sustainable Buildings community, but what do these data represent?


Thank you

Hello,

For more information about the All Sky Surface Shortwave Downward Irradiance parameter you can visit here on the NASA POWER Project Website. NASA's POWER Project also offers mulitple data access options including their web mapping application, Data Access Viewer. For more information on other data services, visit here.

Regards,
ASDC

Hello,

due to my not perfect English I was not clear enough. I would like to know if the "All Sky Surface Shortwave Downward Irradiance" data on an hourly basis for the Sustainable Buildings community (W/m2) represent the maximum, minimum or average value of the total solar irradiance (W/m2) on a horizontal plane. Thanks

Regards

Hello,

The hourly "All Sky Surface Shortwave Downward Irradiance" data is from the CERES SYN1deg data product. From their Data Quality Summary, they state that for the shortwave fluxes, "the integrated cosine of the solar zenith angle is considered the midpoint of the hour box in order to facilitate the hour box averaging" https://ceres.larc.nasa.gov/documents/DQ_summaries/CERES_SYN1deg_Ed4A_DQS.pdf. As such, it is closer to an hourly mean than a maximum or minimum value for the hour.