Data Sources¶
The POWER project provides data at the native source resolutions from the data providers; primary solar resolution is a global 1° x 1° latitude/longitude grid from CERES SYN1deg while the meteorological data source is ½° x ⅝° latitude/longitude grid from GMAO MERRA-2. As data becomes available from providers, it is processed and made available through POWER's services suite.
Energy Fluxes¶
The energy flux parameters (e.g. Solar Irradiance, Thermal IR, and Cloud Properties) are derived from NASA Langley Research Center's SRB Release 4-Integrated Product (R4-IP) archive in association with the GEWEX program and NASA's CERES SYN1deg and FLASHFlux projects. The CERES Version 4A data is processed by the POWER team on a daily basis and appended to the daily time series to provide low latency products which are generally ready within about four days of near real time.
| Source | Temporal Coverage | Latency | |
|---|---|---|---|
| SRB 4.0-IP | January 1, 1984 | December 31, 2000 | |
| CERES SYN1deg Edition 4.2 | January 1, 2001 | NRT minus ~3-4 months | |
| CERES FLASHFlux Version 4A | NRT ~3-4 months | Near Real Time | 5-7 Days |
Warning
The CERES project announced a processing delay for the hourly and daily SYN1deg affecting the availability of POWER’s radiation data starting in August 2024. Limited near real time (NRT) daily solar irradiance data will still be available from CERES FLASHFlux. A new version that provides hourly NRT data will be available mid-summer.
Warning
The time series of daily surface energy fluxes data may include multiple data sources; accordingly, it is not recommended for use in assessing climate trends that encompass a source data change.
Meteorological¶
Meteorological parameters are derived from NASA's GMAO MERRA-2 assimilation model and GEOS-IT. MERRA-2 is a version of NASA's Goddard Earth Observing System (GEOS) Data Assimilation System (Bosilovich, M. G., et al 2016). GEOS-IT has the same grid resolution as MERRA-2 (and the same model physics less selected observations and surface rain gauge normalized precipitation). The POWER team processes GEOS-IT data on a daily basis, and it is appended to the end of the MERRA-2 daily time series to provide low latency products, which are generally ready within about two days of real-time. The MERRA-2 values in the resulting daily time series are typically updated every several months.
| Source | Temporal Coverage | Latency | |
|---|---|---|---|
| GMAO MERRA-2 | January, 1, 1981 | Month Behind Near Real Time | |
| GEOS-IT | End of MERRA-2 | Near Real Time | 2 Days |
Warning
The time series of daily meteorological data will include MERRA-2 or GEOS-IT data within a few months of Near Real Time; accordingly, it is recommended to end your analysis 2 months behind NRT when assessing climate trends.
Precipitation¶
POWER's higher resolution precipitation data is derived from NASA's Global Precipitation Measurement (GPM) mission's Integrated Multi-satellitE Retrievals for GPM (IMERG). The resolution of the IMERG precipitation data is a global 0.1° x 0.1° latitude/longitude grid (approximately 10km).
| Source | Temporal Coverage | Latency | |
|---|---|---|---|
| IMERG Final Run | January, 1, 2001 | 3.5 Months Behind Near Real Time | 3.5 Months |
| IMERG Late Run | End of IMERG Final Run | Near Real Time | 14 hours |
Warning
- The IMERG data is only available at the daily temporal and in UTC time in POWER's Services.
- The time series of UTC daily IMERG precipitation data will include both Late and Final Run data within a few months of Near Real Time; accordingly, it is recommended to end your analysis 3.5 months behind NRT when assessing climate trends.