Earth Data School
About
Full catalog/PREFIRE_SAT1_2B-FLX_COG
PREFIRE_SAT1_2B-FLX_COG·vR01·dataset

Heat the poles radiate to space in far infrared (PREFIRE)

Polar Radiant Energy in the Far InfraRed Experiment (PREFIRE) Spectral Flux from PREFIRE Satellite 1 COG R01
atmosphere NASA LARC_CLOUD Level 2B active TIFF
In plain English

What it measures. How much heat energy the polar regions radiate out to space, especially in far-infrared wavelengths that have rarely been measured before, expressed as outgoing longwave radiation on a roughly 2 km grid.

How it's made. Derived from the PREFIRE infrared spectrometer aboard a small CubeSat, combined with cloud and atmospheric inputs and rendered into mapped GeoTIFF files.

How & where you'd use it. Helps fill a gap in understanding Earth's energy budget at the poles, feeding climate and circulation models to improve predictions.

What's measured

ATMOSPHERE › ATMOSPHERIC RADIATION › EARTH RADIATION BUDGETATMOSPHERE › ATMOSPHERIC RADIATION › OUTGOING LONGWAVE RADIATIONATMOSPHERE › ATMOSPHERIC RADIATION › LONGWAVE RADIATION › UPWELLING LONGWAVE RADIATIONATMOSPHERE › ATMOSPHERIC RADIATION › RADIATIVE FLUX

Coverage & cadence

  • Time span2024-07-24 → ongoing
  • Measured byPREFIRE-SAT1 (TIRS-PREFIRE)
  • Processing levelLevel 2B
  • Spatial extent-180, -90, 180, 90
  • FormatsTIFF
  • StatusACTIVE

What you can do with it

  • Map air pollutants — NO₂, aerosols, ozone
  • Track greenhouse gases and Earth's energy budget
  • Feed weather and air-quality analysis
Official description

Polar Radiant Energy in the Far InfraRed Experiment (PREFIRE) Spectral Flux from PREFIRE Satellite 1 COG (PREFIRE_SAT1_2B-FLX_COG) is retrieved from data collected by the PREFIRE Thermal Infrared Spectrometer (TIRS-PREFIRE) aboard PREFIRE-SAT1. Dual CubeSats each carry a PREFIRE Thermal Infrared Spectrometer (TIRS-PREFIRE), a push broom spectrometer with 63 channels measuring mid- and far-infrared (FIR) radiation from approximately 5 to 53 µm. Most polar emissions are in the FIR but have not been measured on a large scale. PREFIRE aims to fill knowledge gaps in the global energy budget by more accurately characterizing polar emissions. This information will then be assimilated into global circulation and other models to predict future conditions more accurately. PREFIRE_SAT1_2B-FLX_COG contains Cloud-Optimized GeoTIFF (COG) files that each contain a georeferenced rendering of derived outgoing longwave radiation (OLR) values. Those OLR data values are computed from a single granule of PREFIRE Spectral Radiance (PREFIRE_SAT1_1B-RAD) data, along with inputs from PREFIRE_SAT1_2B-MSK (cloud mask), PREFIRE_SAT1_AUX-MET, PREFIRE_SAT1_AUX-SAT, and PREFIRE_SAT1_2B-CLD. As part of the rendering process, mean derived OLR values are computed for a global grid of raster elements (each approximately 2.23 km in width), based on which raster elements each PREFIRE ground footprint overlaps. This procedure is done in order to better visualize the PREFIRE data despite substantial overlap of adjacent along-track ground footprints – but it is important to remember that the individual PREFIRE ground footprints are much bigger (by about 80x, in terms of area) than each of the GeoTIFF raster elements. These cloud-optimized GeoTIFF images may be viewed using many geographic information systems (GIS), such as the freely available QGIS. Science data retrieval started July 24, 2024 and is ongoing. Currently, the geographic coverage is for latitudes between approximately 60° to 84° in both polar regions, although future releases may include data for all latitudes equatorward of about 84°. Within the orbital swath there are eight distinct tracks of data associated with the eight separate spatial scenes for each TIRS-PREFIRE. At the beginning of the mission, the approximate scene footprint sizes were 11.8 km x 34.8 km (cross-track x along-track), with gaps between each scene of approximately 24.2 km. The entire swath was about 264 km across. Note that the scene footprint and swath sizes quoted here are for the orbit altitude soon after launch. However, the footprint and swath sizes will slowly become smaller as the orbit altitude decreases with time. Similar OLR GeoTIFF renderings for the sister instrument aboard PREFIRE-SAT2 can be found in the PREFIRE_SAT2_2B-FLX_COG collection.

Get the data

prefire_sat1_2b-flx_cog_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="PREFIRE_SAT1_2B-FLX_COG",
    version="R01",
    bounding_box=(-122.5, 37.2, -121.8, 37.9),  # your area (W,S,E,N)
    temporal=("2024-01-01", "2024-12-31"),       # your dates
)
files = earthaccess.open(results)   # stream straight from LARC_CLOUD
Browsing CMR needs no login. Downloading or streaming bytes needs a free Earthdata Login + the earthaccess package.