What is the spatial resolution of the POWER data?

The POWER solar data were initially produced on a 1° latitude/longitude grid and subsequently re-gridded via data replication to a 0.5° latitude, longitude grid cells. The latitude, longitude value for the cell is at the lower left corner of the cell.

The POWER meteorological data were initially produced on a 1/2° by 2/3° global grid and then bi-linearly interpolated by the POWER project to a global 0.5° grid. The latitude, longitude value for the cell is at the center of the cell.

What is the temporal resolution of the POWER data?

The POWER solar data are initially produced on 3-hourly time increments which are averaged to provide daily values. The daily averaged values are used to calculate climatologically averaged monthly values.

The meteorological data are initially produced on 1-hourly time increments which are averaged to provided daily values. The daily averaged values are used to calculate climatologically averaged monthly values.

Where is this data derived?

The POWER solar data are inferred via radiative transfer models from satellite observations. Solar data are taken from the NASA GEWEX SRB and the FLASHFlux projects. Specific time periods associated with each project are listed in the methodology documentation.

The POWER meteorological data are taken from the most current NASA’s Global Model and Assimilation Office assimilation model. The most current model is given in the methodology documentation.

How do I access a requested file (ASCII, CSV, ICASA, GeoTIFF, NetCDF) from the API?

JSON is the default response for all data requests. Please see the 'outputs' section at the bottom of the JSON response for a link to the requested file.

What are the different ways to access the POWER data?

The POWER data can be downloaded as daily time series files or as climatologically monthly averaged values.

Who do I contact if I have a question?

Inquiries regarding the POWER data can be made at power-project@lists.nasa.gov.

Why is the elevation given for the POWER data different from the surface station values?

The POWER data, including the elevation value, represent average values over 1/2° latitude, longitude grid cells. In complex terrain, such as mountains, the averaged elevation of the grid cell can be substantially different from the local elevation of a local surface site.

Are sunshine data (sunshine hours /day; or percentage insolation) and Solar Radiation Global available in POWER?

The annual averaged global solar radiation and the monthly averaged daylight hours are available at:

Can one access/download POWER data from multiple locations without entering an individual latitude, longitude coordinate?

Contact the POWER project office at power-project@lists.nasa.gov for help in downloading data files from multiple surface sites.

Does the POWER solar insolation represent net radiation or solar radiation requiring an additional cloud term?

The POWER solar values are the downward solar radiation reaching the earth's surface for all sky conditions. The influence of clouds has been taken into account in computing the solar values. The POWER data does not provide the net radiation defined as difference between the incoming and outgoing radiation.

Are hourly data available?

Hourly data are not available at this time

Do the solar insolation values include cloudiness?

The all sky values do include cloudiness. The clear sky values are determined for various cloud 'free' conditions.

What is the accuracy of the POWER solar and/or meteorology data?

The accuracy of both the solar and meteorology data are evaluated through direct comparisons with surface site observations. Results from the comparisons are documented in the methodology documentation.