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Full catalog/SMODE_L1_ASIT_SLOPEFIELDS_V1
SMODE_L1_ASIT_SLOPEFIELDS_V1·v1·dataset

Ocean wave slope measured from a sea tower

S-MODE Pre-Pilot Ocean Wave Slope from Visible-Band Polarimetry at the Air-Sea Interaction Tower Version 1
ocean NASA POCLOUD Level 1 netCDF-4
In plain English

What it measures. Extremely detailed maps of the tilt of the ocean's surface (wave slope) over a small patch of water, captured many times per second at millimeter-scale detail.

How it's made. Recorded by a polarimetric camera mounted on the Air-Sea Interaction Tower, which reconstructs the water surface tilt from the polarization of reflected light, with no instrument in the water.

How & where you'd use it. Used to study small ocean waves and how the sea surface roughens, part of a pilot ocean dynamics experiment; the data are preliminary and the makers ask users to consult the researcher before using them.

What's measured

OCEANS › SEA SURFACE SLOPE

Coverage & cadence

  • Time span2019-10-07 → 2020-01-18
  • Measured byFIXED OBSERVATION STATIONS (STOKES POLARIMETER)
  • Processing levelLevel 1
  • FormatsnetCDF-4
  • StatusCOMPLETE

What you can do with it

  • Watch sea-surface temperature and marine heatwaves
  • Spot algal blooms and ocean-colour shifts
  • Support fisheries and coastal monitoring
Official description

These wave slope data from polarimetry described below are considered preliminary and should not be used for any purpose without consulting Chris Zappa (zappa@ldeo.columbia.edu). This data set includes tower-based measurements of ocean wave slope fields from visible-band polarimetry using a Polaris Pyxis Mono VIS polarimetric camera. The data here include wave slope fields at 30 frames per second temporal resolution and mm-scale spatial resolution over a ~2 m x 2 m area of ocean surface observed off the Air-Sea Interaction Tower (ASIT; 41°20.1950'N, 70°33.3865'W). Measurements were taken over the period from October 2019 through January 2020. Surface slopes are along two dimensions: along-look and cross-look orientations of the camera. Data was acquired for 10 minutes per hour, 8 hours per day, and each data file (netCDF-4) captures one of the 10-minute segments. Note that data files are large, 142 GB each. Data were collected as part of a pre-pilot campaign for the S-MODE (Submesoscale Ocean Dynamics Experiment) project. The polarimetric slope sensing (PSS) technique of Zappa et al. [2008] allows one to reconstruct the water surface slope field by measuring the polarization state of reflected light at each image pixel, allowing for surface resolutions of order 1 mm with no in-water measurement component. From these data one is able to compute water surface slope variance, wave directional spreading, and the near-surface current profile.

Get the data

smode_l1_asit_slopefields_v1_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="SMODE_L1_ASIT_SLOPEFIELDS_V1",
    version="1",
    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.