EarthCARE¶

Earth Cloud, Aerosol and Radiation Explorer (EarthCARE) Level 1 and Level 2 products (lidar, radar, imager and radiometer)

Available

At a glance¶

Note on period: In the ESA catalogue the L1 collection runs from 2024-08-11 and the ESA L2 collection from 2025-03-11 to the present. The ESA catalogue lists the JAXA L2 collection from 2024-05-28, but check the actual coverage in JAXA's product listings. No data are acquired during orbit manoeuvres (for example 1–4 and 8–11 September 2026).

Overview¶

EarthCARE is a joint ESA–JAXA mission for clouds, aerosols and radiation that carries a 355 nm high-spectral-resolution lidar (ATLID), a Doppler cloud profiling radar (CPR), a multi-spectral imager (MSI) and a broadband radiometer (BBR) on one platform. The lidar and radar resolve the vertical structure of clouds and aerosols, the imager adds across-track context, and a central goal is to check radiative transfer calculations against the top-of-atmosphere radiation measured by the radiometer. It resumes the spaceborne lidar record interrupted after CALIPSO and provides single-instrument L2A and multi-instrument L2B products.

Available variables¶

Variable names from the ESA product definition documents (PDDs); all sit in the ScienceData group of the data file (.h5). Each quantity has a matching 1-sigma _error variable. quality_status runs from 0 (good) to 4 (missing or bad L1). For cloud products (CPR_CLD_2A, ATL_ICE_2A, MSI_COP_2A and others) and JAXA products, see each product definition document.

instantaneous mean accumulated maximum minimum static — instantaneous: value at the time stamp · mean/accumulated/maximum/minimum: over the indicated interval · static: does not change with time

ATLID aerosol profile (ATL_AER_2A, JSG about 1 km × 100 m)¶

ATLID extinction, backscatter and depolarisation (ATL_EBD_2A)¶

MSI aerosol optical thickness (MSI_AOT_2A, 500 m swath)¶

The full variable list is in the official documentation.

How to get the data¶

• ESA MAAP Explorer — EarthCARE ESA L2 (public collection) — Web search and HTTPS download (zip containing the .h5 data file and .HDR header)
  • A free ESA EO Sign In login is required. L1 (ATL_NOM_1B, MSI_RGR_1C, BBR_NOM_1B, CPR_NOM_1B and others) is downloaded the same way.
• ESA MAAP Catalogue (STAC API) — STAC / OpenSearch API (pystac-client etc.; downloads need an access token)
  • See https://catalog.maap.eo.esa.int/doc/stac.html for usage.
• ESA Earth Online — EarthCARE data overview (collections and processor baseline table) — Web
  • The public collections are L1, ESA L2, JAXA L2, orbit data and X-MET (auxiliary meteorology) L1D. Separate collections are restricted to commissioning and validation teams.
• JAXA G-Portal (CPR L1 and JAXA L2) — Web / SFTP (G-Portal user registration)
  • As checked in 2026-10, JAXA EORC's EarthCARE product list page is still marked 'TBC'.

Example code¶

The STAC collection search adapts the example in the MAAP STAC guide to EarthCARE; confirm the collection IDs from the output. Download files through MAAP Explorer (EO Sign In) or the token-based API, then open the .h5 file with xarray, selecting the ScienceData group.

# pip install pystac-client xarray h5netcdf
from pystac_client import Client
import xarray as xr

api = Client.open("https://catalog.maap.eo.esa.int/catalogue/")
for c in api.collection_search(filter="platform='EarthCARE'").collections():
    print(c.id, "-", c.title)          # find the L1 and L2 collection IDs

# Open an ATL_AER_2A file unzipped from a MAAP Explorer download (example file name)
f = "ECA_EXBD_ATL_AER_2A_20260801T010203Z_20260802T000000Z_12345A.h5"
ds = xr.open_dataset(f, group="ScienceData")
ext = ds["particle_extinction_coefficient_355nm"]          # m-1, (along_track, height)
good = ext.where(ds["quality_status"] <= 1)                  # 0 good, 1 likely good
print(good.mean("along_track").values[:10])

Practical tips¶

• ATLID values are at 355 nm. When comparing AOD or extinction with CALIOP (532 nm) or MODIS (550 nm), correct for or at least state the wavelength difference.
• Using only quality_status 0 and 1 is the usual starting point. Values below fully attenuating clouds are 3, and missing or bad L1 is 4.
• ESA notes that the L2 header flag degradedProductQualityFlag is often set to 1 because it is triggered by the processor exit code. Do not discard files on this flag alone; use the per-variable quality values.
• From 23 April 2026, BD-baseline ATLID data show negative cross-polar values in the stratosphere; a fix is planned for the CA baseline with reprocessing. Treat stratospheric depolarisation with caution.
• From 21 April to 19 May 2026 (BD), a laser-energy normalisation bug produced bands of low backscatter. Check whether data for that period have been reprocessed (baseline letters).
• To extend its life, the BBR is in standby for about 15 of every 20 days and in nominal mode for about 5. BBR-based flux products (BM__RAD_2B, BMA_FLX_2B) have large day-to-day gaps.
• Processor baselines differ by product and change often. State both product name and baseline (for example ATL_AER_2A BD) in publications.
• For cloud studies, the L2B synergy products that combine CPR (94 GHz Doppler radar), ATLID and MSI (AC__TC__2B, ACM_CAP_2B and others) give more robust target classification than single-instrument L2A.

Notices and change history¶

References for your paper¶

Dataset citation¶

ATLID AER L2A, baseline BD — DOI 10.57780/esa-1cdaa09

@misc{earthcare_atl_aer_2a_bd,
  author    = {{European Space Agency}},
  title     = {{EarthCARE} {ATLID} {AER} Level {2A}, version {BD}},
  year      = {2026},
  publisher = {European Space Agency},
  doi       = {10.57780/esa-1cdaa09}
}

ATLID NOM L1B, baseline CA — DOI 10.57780/eca-7a0fa3d

@misc{earthcare_atl_nom_1b_ca,
  author    = {{European Space Agency}},
  title     = {{EarthCARE} {ATLID} {NOM} Level {1B}, version {CA}},
  year      = {2026},
  publisher = {European Space Agency},
  doi       = {10.57780/eca-7a0fa3d}
}

Reference papers¶

EarthCARE mission and system overview — DOI 10.5194/amt-16-3581-2023

@article{wehr2023earthcare,
  author  = {Wehr, Tobias and Kubota, Takuji and Tzeremes, Georgios and Wallace, Kotska and Nakatsuka, Hirotaka and Ohno, Yuichi and Koopman, Rob and Rusli, Stephanie and Kikuchi, Maki and Eisinger, Michael and Tanaka, Toshiyuki and Taga, Masatoshi and Deghaye, Patrick and Tomita, Eichi and Bernaerts, Dirk},
  title   = {The {EarthCARE} mission -- science and system overview},
  journal = {Atmospheric Measurement Techniques},
  volume  = {16},
  number  = {15},
  pages   = {3581--3608},
  year    = {2023},
  doi     = {10.5194/amt-16-3581-2023}
}

Acknowledgements¶

ESA issues a separate DOI for each product and baseline (ATL_AER_2A, for example, has separate DOIs for baselines AE and BD). Look up the DOI for the product and baseline you used on the ESA catalogue page and cite it. The citations above are built from the DataCite metadata (creator ESA, year, title, version). Use of the data is governed by the ESA terms and conditions.

Information on the datasets used in this study was compiled with the help of the Korean Climate Data Navigator (KCDN) (Sim, 2026; https://doi.org/10.5281/zenodo.23300923).

Links¶

• ESA Earth Online — EarthCARE mission
• EarthCARE Product Data Handbook
• ESA — EarthCARE data quality (known issues)
• ESA catalogue — EarthCARE L1 products
• ESA catalogue — EarthCARE JAXA L2 products
• JAXA EORC — EarthCARE