Water vapor and brightness over ocean, interim (SWOT)
What it measures. How much water vapor and liquid water sit in the air over the ocean, plus related quantities like cloud water and wind speed. This is the early, interim version of the data.
How it's made. Comes from the Advanced Microwave Radiometer on the SWOT satellite (a NASA-CNES mission), processed with preliminary orbit information and calibrations and released quickly.
How & where you'd use it. Mainly used to correct SWOT's ocean-height measurements for atmospheric moisture; the interim label means it's an early release for users who need data fast over polished accuracy.
What's measured
Coverage & cadence
- Time span2022-12-16 → ongoing
- Measured bySWOT (AMR)
- Processing levelLevel 2
- Spatial extent-180, -77.6, 180, 77.6
- FormatsnetCDF-4
- StatusSUPERSEDED
What you can do with it
- Track deforestation, fire scars and land-cover change
- Monitor crop and vegetation health (NDVI/EVI)
- Map how built-up vs. green an area is over time
Official description
The SWOT Level 2 Radiometer Brightness Temperatures and Troposphere Interim Geophysical Data Record (IGDR) Version 1.0 dataset produced by the Surface Water and Ocean Topography (SWOT) mission provides atmospheric water vapor and liquid water content from the Advanced Microwave Radiometer (AMR), a Jason-class radiometer that measures sea surface brightness temperatures at three microwave frequencies (18.7, 23.8 and 34 GHz). Brightness temperatures are processed to estimate the wet troposphere content, atmospheric attenuation to backscatter, cloud liquid water, water vapor content, and wind speed coincident with each range measurement from the nadir altimeter and applied to correct for altimeter range delays caused by atmospheric effects. SWOT is a joint mission between NASA and CNES that launched on December 16, 2022. It aims to measure ocean surface topography with unprecedented resolution and accuracy, as well as map inland water bodies globally. The interim radiometer dataset consists of discrete measurements along two tracks located approximately 30-km to the left and right of the satellite nadir. The data were processed using the Medium-accuracy (preliminary) Orbit Ephemeris (MOE) with preliminary calibrations applied. They are distributed as one file per half-orbit in netCDF4 file format with a nominal latency of < 1.5 days.
Get the data
import earthaccess
earthaccess.login(strategy="netrc") # free Earthdata Login
results = earthaccess.search_data(
short_name="SWOT_L2_RAD_IGDR_2.0",
version="2.0",
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 POCLOUD Browsing CMR needs no login. Downloading or streaming bytes needs a free Earthdata Login + the earthaccess package. Official links
- Data Use and Citation Guidelines VIEW RELATED INFORMATION
- SWOT User Handbook VIEW RELATED INFORMATION
- SWOT Mission Page VIEW RELATED INFORMATION
- SWOT Mission Page at NASA VIEW RELATED INFORMATION
- SWOT Mission Page at JPL VIEW RELATED INFORMATION
- SWOT Mission Page at PO.DAAC VIEW RELATED INFORMATION
- SWOT Mission Page at AVISO VIEW RELATED INFORMATION
- HTTPS endpoint for data browse and download GET DATA