Aerosol sun photometry state of the art and progress and the COST action Harmonia
- 1Physikalisch-Meteorologisches Observatorium Davos, World Radiation Center (PMOD/WRC), Davos Dorf, Switzerland (stelios.kazadzis@pmodwrc.ch)
- *A full list of authors appears at the end of the abstract
We intend to present and overview of ground-based sun photometry for aerosol optical properties retrieval, including:
- the state of the art on basic principles of direct sun and sky radiance measurements and retrieval methods used worldwide
- Calibration procedures for aerosol optical depth
- Global efforts for aerosol optical properties homogenization
- An estimation of the aerosol optical depth uncertainty and the factors affecting it
- Examples of aerosol retrievals, trends and spatiotemporal variability on a global scale.
Currently, global networks retrieving aerosol properties (e.g. aerosol optical depth (AOD)) are using different calibration principles and hierarchy and also there are differences on the post processing of solar direct sun measurements, in order to retrieve AOD (e.g. inclusion of trace gases, cloud elimination , Rayleigh scattering effects). Concerning the calibration, the most common methods are the Langley calibration (with certain limitations) and the traceability to defined (e.g. from WMO) standards. Lately a link of such standards with SI traceable ones helped towards the goal of the transition from "artificial" standards towards SI traceable ones.
Long term measurements of various instruments belonging to different networks showed, in the case of network reference instruments, very good agreement within initatives supported by the world meteorological organization ( e.g. filter radiometer comparisons in Davos, Switzerland from 2000 to 2021 organized by the World Optical depth Research and Calibration Center) and European infrastructure initiatives such as ones supported by the Calibration center for Atmospheric remote sensing of the EU infrastructure ACTRIS (Aerosol, Clouds and Trace Gases Research Infrastructure).
Recently these aspects have been investigated and communicated through a networking COST action project called Harmonia (International network for harmonization of atmospheric aerosol retrievals from ground based photometers) where more than 100 scientists are participating.
Acknowledgement: The presenter would like to acknowledge funding for the participation at EMS2023 from the COST Action HARMONIA (International network for harmonisation of atmospheric aerosol retrievals from ground based photometers), CA21119
C. Toledano, L. Doppler, M. Campanelli, V. Estelles, R. Roman, I. Fountoulakis, S. Solomos, S. Vandenbussche , A. Nemuc, P. Raptis, P. Dagsson-Waldhauserova, M. J. Costa, K. Papachristopoulou
How to cite: Kazadzis, S., Kouremeti, N., Masoom, A., and Groebner, J. and the Harmonia Core group Team: Aerosol sun photometry state of the art and progress and the COST action Harmonia, EMS Annual Meeting 2023, Bratislava, Slovakia, 4–8 Sep 2023, EMS2023-41, https://doi.org/10.5194/ems2023-41, 2023.
