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Full catalog/PACE_OCI_L2_CLOUD_MASK_NRT
PACE_OCI_L2_CLOUD_MASK_NRT·v3.1·dataset

Where the clouds are, fast delivery (PACE, near real-time)

PACE OCI Level-2 Regional Cloud Mask - Near Real-time (NRT) Data, version 3.1
land NASA OB_CLOUD Level 2 active netCDF-4
In plain English

What it measures. A map flagging which pixels are covered by clouds (or sit right next to clouds), so other measurements can either focus only on cloudy areas or screen clouds out.

How it's made. Produced quickly (near real-time) from the OCI instrument on the PACE satellite, using best-available supporting data; the fast turnaround means inputs are less refined than the standard product.

How & where you'd use it. A behind-the-scenes helper used to clean up other ocean and atmosphere products - for example removing cloud-edge artifacts before estimating chlorophyll - rather than a standalone result.

What's measured

Spectral/Engineering › Visible WavelengthsAtmosphere › Clouds

Coverage & cadence

  • Time span2024-03-05 → ongoing
  • Measured byPACE (OCI)
  • Processing levelLevel 2
  • Spatial extent-180, -90, 180, 90
  • FormatsnetCDF-4
  • StatusACTIVE

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 Ocean Biology DAAC produces near real-time (NRT) products using the best-available combination of ancillary data from meteorological and ozone data. As such, the inputs and the calibration used are less than optimal. Near real-time products provide a snapshot of the data during a short time period within a single orbit. The Cloud Mask identifies whether pixels are cloud-covered or not. This is important because algorithms to determine cloud properties should only run on cloudy pixels, and other algorithms that require clear-sky pixels need to screen clouds out. In practice, users apply cloud_flag for strict cloud removal and cloud_flag_dilated when they want a conservative mask that reduces cloud-edge artifacts in downstream products (e.g., Rrs, chlorophyll). The CLDMASK is used operationally as the "cloud and cloud-adjacent" screen. Core geophysical variables in this suite include: - cloud_flag - Cloud mask (bitmask; identifies cloud-contaminated pixels) - cloud_flag_dilated - Cloud or cloud-adjacent pixel mask (bitmask; includes surrounding pixels) - l2_flags - Level-2 Processing Flags (bitmask)

Get the data

pace_oci_l2_cloud_mask_nrt_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="PACE_OCI_L2_CLOUD_MASK_NRT",
    version="3.1",
    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 OB_CLOUD
Browsing CMR needs no login. Downloading or streaming bytes needs a free Earthdata Login + the earthaccess package.