Earth Data School
About
Full catalog/ATL23
ATL23·v002·dataset

Hills and dips in the sea surface, monthly (ICESat-2)

ATLAS/ICESat-2 L3B Monthly 3-Month Gridded Dynamic Ocean Topography V002
ocean NASA NSIDC_CPRD Level 3 active HDF5
In plain English

What it measures. Monthly gridded maps of how the sea surface humps up and dips down (dynamic ocean topography) across midlatitude and polar regions, with uncertainty estimates and wave statistics included.

How it's made. Derived from the ICESat-2 satellite's laser altimeter measurements of ocean surface height, averaged into gridded monthly products.

How & where you'd use it. Used in physical oceanography to study ocean currents and sea-surface behavior; the per-beam versions also help researchers spot measurement biases.

What's measured

OCEANS › SEA SURFACE TOPOGRAPHY › SEA SURFACE HEIGHT

Coverage & cadence

  • Time span2018-10-13 → ongoing
  • Measured byICESat-2 (ATLAS)
  • Processing levelLevel 3
  • Spatial extent-180, -88, 180, 88
  • FormatsHDF5
  • StatusACTIVE

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

ATL23 contains monthly 3-month gridded averages of dynamic ocean topography (DOT) over midlatitude, north-polar, and south-polar grids derived from the along-track ATLAS/ICESat-2 L3A Ocean Surface Height product (ATL12). Monthly gridded sea surface height (SSH) can be calculated by adding the mean DOT and the corresponding weighted average geoid height. Both single beam and all-beam gridded averages are available: single beam averages are useful for identifying potential biases among the beams, and the all-beam averages are useful in physical oceanography. Simple averages, degree-of-freedom averages, and averages interpolated to the center of grid cells are included, as well as uncertainty estimates. Sea surface statistics histograms and wave statistics within grid are also provided.

Get the data

atl23_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="ATL23",
    version="002",
    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 NSIDC_CPRD
Browsing CMR needs no login. Downloading or streaming bytes needs a free Earthdata Login + the earthaccess package.