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Full catalog/PACE_HARP2_L2_CLOUD_GPC_NRT
PACE_HARP2_L2_CLOUD_GPC_NRT·v3.0·dataset

What clouds are made of, live (PACE HARP2)

PACE HARP2 Level-2 Regional Cloud Optical Properties, GISS Polarimetric Cloud (GPC) Algorithm - Near Real-time (NRT) Data, version 3.0
atmosphere NASA OB_CLOUD Level 2 active netCDF-4
In plain English

What it measures. Describes what clouds are made of — the size of their droplets, how many droplets they hold, how much liquid water they carry, and how thick they are.

How it's made. Derived in near-real-time from the HARP2 polarimeter on NASA's PACE satellite using the GISS Polarimetric Cloud method, combined with companion measurements from PACE's OCI instrument.

How & where you'd use it. Supports cloud and climate research; because applying this polarimetric approach globally is new, several variables are experimental and may change in future versions.

What's measured

Atmosphere › Clouds

Coverage & cadence

  • Time span2024-02-05 → ongoing
  • Measured byPACE (HARP2)
  • 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 CLOUD_GPC suite provides cloud properties derived from the GISS Polarimetric Cloud (GPC) algorithm, along with additional variables obtained through combination with the OCI CLOUD suite. Given the novelty of implementing a polarimetric algorithm on a global scale, note that several experimental variables—particularly those intended for diagnostic purposes and future refinement—are included and may change in subsequent, more mature versions. Core geophysical variables in this suite include: - cloud_droplet_effective_radius / variance - Cloud droplet effective radius and variance (µm, unitless) - cloud_droplet_number_concentration - Droplet number concentration (combining with OCI CLOUD) (cm⁻³) - cloud_liquid_water_path - Cloud liquid water path (combining with OCI CLOUD) (g m⁻²) - cloud_liquid_index - Index measuring polarized primary bow strength (unitless) - cloud_optical_thickness - Cloud optical thickness (from OCI CLOUD) (unitless) - cloud_bow_extinction_cross_section_Xnm – 355/532 nm extinction cross section based on Cloud Bow retrievals - cloud_bow_lidar_ratio_Xnm – 355/532 lidar ratios based on Cloud Bow retrievals - cloud_rft_* - Retrievals from Rainbow Fourier Transform (experimental and exploratory, intended for future substantial refinements) - cloud_top_properties - Cloud top altitude (m), pressure (hPa), and temperature (K) (from OCI CLOUD)

Get the data

pace_harp2_l2_cloud_gpc_nrt_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="PACE_HARP2_L2_CLOUD_GPC_NRT",
    version="3.0",
    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 OB_CLOUD
Browsing CMR needs no login. Downloading or streaming bytes needs a free Earthdata Login + the earthaccess package.