AERONET

AERONET
Public domain · source
Name	AERONET
Established	1993
Operator	NASA
Discipline	Atmospheric science
Location	Global

AERONET AERONET is a federated ground-based network of sun photometers providing long-term aerosol optical properties used for satellite validation, climate research, and air quality studies. It integrates standardized instruments, automated retrieval algorithms, and centralized data archives to support observational programs coordinated by agencies such as NASA, the CNES, and university partners. The project underpins cross-disciplinary efforts involving satellite missions, field campaigns, and modeling centers.

Overview

AERONET was initiated to provide globally distributed, ground-truth aerosol observations complementing platforms like MODIS, CALIPSO, MISR, VIIRS, and SeaWiFS. It operates in synergy with programs including GCOS, GEWEX, IGAC, SPARC, and IPCC assessment activities. Major institutional contributors include NASA, the Université Paul Sabatier, the Laboratoire d'Optique Atmosphérique, and national agencies such as NOAA, ESA, JAXA, CONAE, and ISRO. AERONET data inform satellite validation efforts for missions like Terra (satellite), Aqua (satellite), Sentinel-3, Suomi NPP, and proposed constellations from SpaceX and OneWeb partnerships. The network interacts with field studies led by groups at Scripps Institution of Oceanography, CNRS, University of Miami, Purdue University, and Max Planck Institute.

Instrumentation and Retrieval Algorithms

Standardized instruments include the Cimel Electronique sun/sky photometer model used in major campaigns associated with ACE-Asia, ARCTAS, SEAC4RS, and AMMA. The photometers operate at wavelengths similar to sensors aboard ERS-2, Envisat, and Landsat 8. Retrieval algorithms derive aerosol optical depth (AOD), Angström exponent, and aerosol size distributions via inversion schemes developed alongside researchers from Lois W. King Lab, NASA Goddard Space Flight Center, Laboratory for Atmospheric and Space Physics, and AEROCENTRE teams. Algorithms employ radiative transfer codes related to those used in DISORT and compare with lidar products from EARLINET, MPLNET, and NDACC lidars. The inversion framework references Mie theory applications used by groups at University of Oxford, Imperial College London, and University of Tokyo to estimate real and imaginary refractive indices.

Data Products and Formats

AERONET distributes standardized levels of data including Level 1.0 (unscreened), Level 1.5 (cloud-screened), and Level 2.0 (quality-assured), mirroring conventions used by GHRSST and GCMD. Products encompass AOD, columnar water vapor, single scattering albedo (SSA), and direct-normal irradiance compatible with models run at NCAR, ECMWF, UK Met Office, and NOAA GFS. Formats include ASCII, NetCDF CF-compliant files used by MPI-M, ESGF archives, and metadata structures referenced by DODS/OPeNDAP services. Data interoperability supports assimilation into chemical transport models such as GEOS-Chem, CMAQ, and WRF-Chem, and facilitates comparisons with reanalyses like MERRA-2 and ERA5.

Network Deployment and Sites

The network spans continental, coastal, island, and polar observatories including long-term sites at Mauna Loa Observatory, Barrow (Alaska), Punta Arenas, Izaña Observatory, and Cape Verde Atmospheric Observatory. Regional clusters support projects in Amazon rainforest, Sahara Desert, Himalaya, and Australian Outback deployments, coordinating with local institutions such as INPE, CSIR, CICERO, FAPESP, and CSIRO. Collaborative arrays have been installed at campaign locations connected to IPY activities and polar research stations like McMurdo Station and Ny-Ålesund. The network expansion engages national networks including AERONET-OC coastal nodes and partnerships with observatories in China Meteorological Administration, Korea Meteorological Administration, and Indian Institute of Tropical Meteorology.

Applications and Scientific Impact

AERONET data underpin studies of aerosol radiative forcing, cloud–aerosol interactions, and health-relevant particulate exposure, informing assessments by the IPCC and policy bodies like the United Nations Environment Programme. Results have been integrated into climate model evaluations at GISS, Hadley Centre, and Potsdam Institute for Climate Impact Research and used in trend analyses by teams at SLAC National Accelerator Laboratory and Lawrence Berkeley National Laboratory. AERONET has supported volcanology campaigns examining eruptions from Mount Pinatubo, Eyjafjallajökull, and Mount St. Helens, urban air quality studies in Los Angeles, Beijing, Delhi, and Mexico City, and biomass burning research linked to events in Indonesia, Amazon Basin, and Southern Africa. The dataset aids satellite algorithm development for missions by NOAA, ESA, JAXA, and space agencies such as Roscosmos and CSA.

Quality Control and Uncertainty Assessment

Quality control procedures include automated cloud-screening, calibration against Langley plot references at high-altitude sites like Mauna Loa, and intercomparisons performed at calibration facilities associated with NIST and university labs at NASA Ames Research Center. Uncertainty characterization addresses instrument drift, calibration transfer, and algorithmic biases evaluated in multi-institutional intercomparison studies involving AEROCOM model ensembles, the BAS aerosol group, and validation teams from EC-JRC. Metadata standards and provenance practices align with recommendations from WMO, IOCCG, and CEOS to ensure traceability for users within the climate modeling and observational communities.

Category:Atmospheric observation networks