WG1 aims to enhance pan- European and Global research coordination in order to:

• optimize and homogenize aerosol columnar products from direct and diffuse irradiance measurements, and study their new related uncertainties;
• improve already existing products and tools dealing with the new challenges at the limit of the aerosol retrieval techniques.
• Suggest standardization methodologies for calibration and post processing algorithms.

More specific the quality of different calibration methods applied to all the instruments involved in the action will be studied by estimating the accuracy and the uncertainty of the direct irradiance measurements and their retrieved product. Additionally the  homogenization of calibration procedures and development of “on site” calibration procedures will be investigated.

 Homogenization of the algorithms for the retrieval of AOD from solar direct irradiance will be attempted : recommend a standard operational procedure report (common conventions on level categorization, on cloud screening and on computation of air mass, Rayleigh optical depth, optical depth of trace gases), and estimation of aerosol optical properties.

Uncertainties concerning aerosol columnar products from sky radiance measurements during different atmospheric conditions and sites’ characteristics as provided by already existing methods, will be reported.

WG2 aims at the establishment of a cooperation network working towards measurement improvement. In this WG data already stored in the datacenter of each international network of photometers, or of independent instruments, will be checked to find co-located sites providing the same optical properties with different equipment and method of analysis; Also, links with the metrology community (MAPP) will provide the opportunity to work towards reducing calibration uncertainties through standardization to a traceable system of S.I. units; In addition night time AOD data from previous and planned campaigns will be analyzed. Short Term Scientific Missions (STSM) will be used to achieve specific goals, such as data analysis and result interpretation.

In the framework of G2, a list will be created of existing field campaigns or experiments including daytime/nightime aerosol retrievals and low cost sensors and a database with data from existing networks (GAW, Aeronet, Skynet and Pandonia) and other independent instruments more suitable for performing intercomparisons.

An analysis of the collected measurements will be performed and presentation of the results on measurement improvements.

 MAPP metrology related results will be linked with HARMONIA

Machine learning and cloud computing approaches for data improvement and homogenization will be investigated

WG3 aims at fostering coordination between academia, operational agencies and industrial partners, in order to increase the applicability of the aerosol products. Demonstration of the relevance of aerosol optical properties to various communities (satellite atmospheric composition, solar energy, aerosol forecasting, aviation).

Identification/invitation of communities of potential users (in addition to the Harmonia participants): Climate, satellite measurements, modeling, solar energy resource and forecasting, health and aviation.

Investigate and report on the role of aerosol uncertainty on user requirements
Define the needs of stakeholders, assess the adaptation of photometry aerosol products to increase the usefulness and applicability

WG4 aims to create a hub among scientists and the industrial sector including instrument and software developers. The main aim is to demonstrate the possibilities of improvements based on synergistic and standardization aspects (WG1 to 2) and also inform on the needs of new technologies towards specific end user goals (WG3).

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.

Establish a collaboration platform among scientists and instrument manufacturers aiming on instrument hardware improvement, linked with retrieval algorithms, towards improvement of aerosol retrieval accuracy.

Suggest software, hardware and other aerosol retrieval improvements including low sensors assessment and share the information with major industrial developers inside and outside HARMONIA network.

Establish a mechanism in order to introduce to aerosol scientists and instrument users inside and outside the HARMONIA consortium, the outcome of the WG1-4 activities towards measurement improvement, new techniques and measurement approaches, sharing of protocols etc.

• Aspects of the entire processing chain; from measurement to end-user products
• Disseminate scientific results and end user aerosol related activities towards different audiences (scientists, public, industry, government bodies).
• Exchange and combine software and hardware user tools among partners towards retrieval improvements
•  Publish scientific results of HARMONIA collaboration to peer reviewed journals, conferences and reports