International network for harmonisation of atmospheric aerosol retrievals from ground based photometers

Aerosols are particles floating in the Earth’s atmosphere linked with the largest uncertainty on estimates and interpretations of the Earth’s changing energy budget. Measurement principles differ depending on the desired derived aerosol optical parameter and on the measurement platform.




The objective of the Action is to improve and homogenize aerosol retrievals by establishing a network of institutions, instrument developers, scientific and commercial end users.




The common aerosol columnar properties’ retrieval techniques, consists of direct measurement of a bright source of radiation (sun, star, moon, sky) with multi-wavelength photometers.
Several global photometric aerosol networks exist, whiinstrumental, algorithm and hardware based differences on their related aerosol products and a global standardization is needed.


Work Plan


The work plan is structured into 5 Working Groups
And it will include short term scientific missions and workshops.




Establish a network involving institutions, instrument developers, scientific and commercial end users, in order to improve, homogenise and valorise aerosol retrievals, using mainly solar and sky but also lunar and star photometers from different networks

Meet the Working Groups


of established techniques
and existing tools

Establish a cooperation network towards knowledge exchange and create a scientific roadmap on worldwide homogenization of aerosol properties’ measurements including calibration, standard operation, quality assurance and control procedures and post processing


Improvement of
aerosol products

Improve the solar, lunar and stellar measurements and data quality. Exploit existing measurement experimental data for different aerosol environments. Breaking new grounds for aerosol retrieval techniques including calibration improvement (via S.I. traceable related standardization results), hardware and software improvement actions


End user engagement towards
maximizing aerosol
measurement use

Increase the applicability of the aerosol photometry products in the larger atmospheric and climate research community. Demonstrate the relevance of aerosol optical properties to various communities (satellite atmospheric composition, solar energy, aerosol forecasting and aviation). Identify new value- added products resulting from synergistic approaches. Create an assessment of current measurement uncertainties versus user needs and defining a road map towards future measurement improvements needed.


Industry engagement towards innovative hardware, software products

Establish a cooperation network towards knowledge exchange and create a scientific roadmap on worldwide homogenization of aerosol properties’ measurements including calibration, standard operation, quality assurance and control procedures and post processing


Project results dissemination

Establish a mechanism in order to: introduce to aerosol scientists and instrument users (inside and outside the HARMONIA consortium), the outcome of the homogenization, the SOPs and the new techniques and measurement improvements.

News and
open calls

Possible STSM/VM subjects

In the framework of WP3 of HARMONIA , some subjects have been suggested for possible STSM and VM collaboration in the near future. The topics are the following: Use aerosol retrievals either to improve satellite products or synergistically with them for different...

2 Phd Vacancies on Ozone Research

2 New Positions for PhD on Atmospheric Ozone Research have been recently announce. Both of them are in Switzerland and funded under the project Quantifying past, present and future Stratospheric and Tropospheric Ozone over the Alps and Europe. One position is at...

2nd MC Meeting 2024, Iceland

  Our annual meeting was held at Reykjavik, IS, the last couple of days. Scientists gathered to discuss the state of the art of aerosol remote sensing. Grantees presented the outcomes of STSMs and VMs of this Action. The strategy for next year was decided. And...

Sky Over BerLIn is over

We are very happy to announce the conclusion of our School , where 35 students were trained on aerosol measurements for three days.  Experts in aerosol remote sensing presented the state of the art at the field. Group exercises provided the opportunity for students to...

New Harmonia Videos

We are very glad to announce a new video explaining all the basics of our science. What are atmospheric aerosols, why are they important and how do we estimate their presence in the Atmosphere. Also, 3 separate videos create the series Decoding Aerosol Measurements,...

Special Thanks to Wetter Museum for providing a tour for students of SkyOverBerLin

The Wettermuseum is a museum of history of meteorological and climatic measurements, over the years.  It hosts a  very large collection of old meteorological instruments. A special focus is given on the history of Meteorological Observatory Lindenberg (1905 -) with...

STSM on Arctic Aerosols

Sandra Graßl did a STSM on the Homogenization of sun, stellar and lunar photometers in the Arctic Region, with very promising results. She was hosted at Universidad de Valladolid and by collaborating with scientists of the institute, she had access to databases of...

HARMONIA session at EMS2024

HARMONIA Action proudly organizes a session at EMS 2024. This session is open for abstracts on all aspects related with aerosol measurements and their interactions with clouds and solar radiation.It includes measurement calibration techniques and satellite calibration...

Sky Over Berlin: Preliminary Program

A preliminary program for the HARMONIA training school "Sky Over Berlin" has just been announced. Stay tuned for more information and final approval of the applicants on early February. download the full program

Sky Over Berlin

🌐 Announcement: Sky over BerLin Training School - HARMONIA's Aerosol Measurements Workshop 📅 Dates: April 8-10, 2024 🚀 Theme: Training on Aerosol Measurements (Sun Photometry) 📝 Registration Deadline: January 31, 2024 📍 Locations: Berlin and Lindenberg, DE 📢Organizer:...