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Full catalog/PACE_OCI_L2_UVAI_UAA_NRT
PACE_OCI_L2_UVAI_UAA_NRT·v3.1·dataset

Index of haze and smoke in the air, live (PACE)

PACE OCI Level-2 Regional Aerosol Index, Unified Aerosol Algorithm (UAA) - Near Real-time (NRT) Data, version 3.1
atmosphere NASA OB_CLOUD Level 2 active netCDF-4
In plain English

What it measures. A quick indicator of light-absorbing haze in the air — mainly smoke and mineral dust. Positive values usually mean an absorbing plume is overhead; values near or below zero mean clearer skies.

How it's made. Calculated in near-real-time from the OCI instrument on NASA's PACE satellite using ultraviolet light, with the trade-off that the speedy processing relies on less-than-ideal supporting data.

How & where you'd use it. Handy for spotting and tracking smoke and dust plumes, supporting air-quality and climate work, and giving context for cleaning up ocean-color images.

What's measured

ATMOSPHERE › AEROSOLS › AEROSOL OPTICAL DEPTH/THICKNESSATMOSPHERE › AEROSOLS › AEROSOL OPTICAL DEPTH/THICKNESS › UV AEROSOL INDEX

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

  • Map air pollutants — NO₂, aerosols, ozone
  • Track greenhouse gases and Earth's energy budget
  • Feed weather and air-quality analysis
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 UAVI_UAA data suite provides the Ultraviolet Absorbing Aerosol Index (UVAI) calculated using the Unified Aerosol Algorithm. UVAI is a unitless, semi-quantitative indicator of light-absorbing aerosols (e.g., smoke, mineral dust), sensitive to their amount, altitude, and absorption strength; positive values typically flag absorbing plumes, while values near/below zero indicate weakly or non-absorbing conditions. Common uses include plume detection and tracking, air-quality and climate analyses, and providing aerosol context for ocean-color atmospheric correction; users should apply recommended screening in the file attributes. Core geophysical variables in this suite include: - NUV_AerosolIndex — Near-UV aerosol index from 0.354/0.388 µm pair (unitless) - NUV_Reflectivity — Near-UV Lambertian equivalent reflectance (LER) at 0.354 and 0.388 µm (unitless) - NUV_Residue — Near-UV LER-based aerosol index from 0.354/0.388 µm pair (unitless)

Get the data

pace_oci_l2_uvai_uaa_nrt_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="PACE_OCI_L2_UVAI_UAA_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.