National Observatory of Athens (NOA) is the first Research Institution created in modern Greece with a continuous presence in science and education activities at international level, for more than 170 years. NOA has been historically nominated by the Greek government as the sole institution in charge of environmental, atmosphere, Earth Observation, Geodynamics, Space, Astronomy and Astrophysics research and relevant studies, with a clear mandate to offer innovative services. ΝΟΑ has important human capacity with high skills in the observation of the atmospheric environment and in particular the investigation of physical processes and interactions in the atmosphere based on atmospheric and meteorological observations and modelling with emphasis on extreme events and climate studies.

NOA expertise related to the project’s objectives

The experimental and theoretical work of the Remote sensing of Aerosols, Clouds and Trace gasses group (ReACT), which is housed in the Institute of Astronomy, Astrophysics, Space Applications & Remote Sensing (IAASARS) of NOA, is dedicated to the application of measuring methodologies for remote sensing of atmospheric processes and its constituents: aerosols, clouds and trace gasses. ReACT/NOA activities are targeted towards understanding physical and chemical processes in the atmosphere, seizing the opportunity provided by the complex and vulnerable Mediterranean environment, utilizing advanced ground-based and space-borne remote sensing observations and theoretical models. The group’s mission is to promote world-class atmospheric research in the area by shedding light on problems of compelling scientific interest and increasing social relevance.

ReACT/NOA has achieved a high-level expertise in (a) aerosol remote sensing and in-situ techniques, (b) deployment and operation of multi-instrument remote sensing and in-situ Research Infrastructure (RI), (c) implementation of intensive experimental campaigns, (d) bridging theoretical research work with industry applications, through lidar system design, development and data exploitation and (e) developing and evaluating of aerosol transport models. The aforementioned techniques are applied for developing reference systems for Cal/Val of ESA missions. ReACT/NOA is currently very active on the Cal/Val of the Aeolus ESA mission, while the leader of the group, Vassilis Amiridis (VA), is an acting member of the Aeolus satellite mission Science and Data Quality Group (SAG) of the European Space Agency. ReACT/NOA has been an active or leading partner in many ESA studies, including the LIVAS and DEDICAtE studies on lidar solutions and techniques for the derivation of homogenized CALIPSO/Aeolus/EarthCARE climate records, and the A-CARE, NEWTON and CORAL projects, for aerosol characterisation and data assimilation of ESA products. Regarding the organization and implementation of ESA experimental campaigns, ReACT/NOA experience includes the Charadmexp, for the characterisation of aerosol mixtures, and is currently organizing the ASKOS tropical campaign, that aims to assess the quality of aerosol and cloud products of Aeolus. ReACT/NOA also participates in the development of the first airborne HSRL lidar of ESA for the validation of its space sensors, through the MULTIPLY ESA activity.

A significant activity of ReACT/NOA is the development and operation of novel lidar systems. Examples include the Wall-E lidar that has been developed in the framework of the ERC consolidator grant D-TECT in collaboration with the Raymetrics S.A., a polarization lidar system for detecting oriented dust particles. Building on the Wall-E lidar, REACT/NOA was granted PM-scanner ERC proof of concept grand aiming to develop a remote sensing instrument which will monitor particulate matter (PM) concentration over large areas with unprecedented accuracy and high spatial and temporal resolution. Another system developed in collaboration with Raymetrics is eVe, a remote sensing reference system tailored to provide quality assured ground-based fiducial measurements for ALADIN/Aeolus aerosol profile products. ReACT/NOA is also responsible for the operation of the advanced 24/7 multi-wavelength backscatter/Raman/depolarisation system PollyXT lidar system operating in Antikythera, Greece. ReACT/NOA implements and operates the Remote Sensing National Facility of the PANGEA Research Infrastructure funded by the European Investment Bank, an atmospheric, climate and geophysical RI being developed by NOA at Antikythera, Greece. The group is also an active member of EARLINET network and ACTRIS Research Infrastructure.

The role of NOA in the project

The role of NOA in this project will be to manage and coordinate the overall effort. The research team for the proposed project will be constituted by experienced atmospheric researchers with high expertise in space-borne and ground-based passive and active remote sensing and atmospheric modelling, to fulfill the objectives of the project (WP1000, WP3000, WP4000, WP5000).

The European Centre for Medium-Range Weather Forecasts (ECMWF) is an independent intergovernmental organization supported by 34 states. The organization was established in 1975 and now employs around 360 staff from more than 30 countries. ECMWF is a multi-site international organization with centers in Reading, UK, Bologna IT and Bonn DE.

ECMWF expertise related to the project’s objectives

ECMWF is both a research institute and a 24/7 operational service, producing and disseminating numerical weather predictions to its Member States. The global numerical weather forecast system to be used in the present study is considered world-leading, and the use of satellite data is the most comprehensive and advanced in the world. The forecasting activities use a supercomputer facility (and associated data archive) that is one of the largest of its type in Europe. It features two Cray XC30 systems and independent Cray Sonexion storage systems.

ECMWF is also the operator of the Copernicus Atmosphere Monitoring Service (CAMS) and the Copernicus Climate Change (C3S) by delegation agreement with the EC. The Integrated Forecasting System (IFS) model is used in the CAMS global monitoring and forecasting component. It is expected that the development that will take place in this programme will be of direct relevance for the production of the next generation of global reanalysis which represent the backbone of the C3S climate service provision. Additionally, ECMWF is involved in the preparation of Destination Earth (currently under negotiation with the European Commission). Atmospheric Composition is one of the elements of one of the Digital Twin, and it is likely that high resolution dust analyses and forecasts will be part of the DestinE activities.

The role of ECMWF in Project

ECMWF will provide CAMS datasets for L2A+, operators for aerosol assimilation and the IFS datasets with and without Aeolus wind assimilation for JATAC. Furthermore, ECMWF will supervise along with NOA WP6000 for consolidating the final recommendations of L2A+.

The Leibniz Institute for Tropospheric Research (TROPOS) is an independent research institution member of the Leibniz Association, with focus on aerosol and clouds. The expertise ranges from physical and chemical laboratory studies, large field experiments in which in-situ and remote sensing techniques from ground and on aircraft are applied, to numerical modelling of cloud processes and aerosol transport. TROPOS has been an active or leading partner in many international projects in the research fields of air pollution and climate. TROPOS is a world-leading center for aerosol and cloud in-situ and remote observations. Over the past two decades, it has contributed to the field with new and innovative technologies and methodologies, e.g. for in-situ measurements of particle size distribution, humidity-dependent and absorption properties, and mixing state of aerosols as well as for remote sensing of particle optical and microphysical properties with multiwavelength Raman and polarization lidars and of cloud-aerosol interactions with combined state-of-the-art aerosol/clouds lidar, wind Doppler lidar, and cloud radar profiling techniques. The institute has been involved in a large number of international field studies in Europe, Asia, Africa, and South America and performs continuous observations at stations worldwide. TROPOS is an active member of EARLINET since 2000 and of CLOUDNET since 2011 and contributes to the respective ACTRIS databases on the four- dimensional distribution of aerosols and clouds over Europe.

The role of TROPOS in Project

TROPOS will provide and analyze the data set acquired during ASKOS/JATAC at Mindelo in September 2021 and from the foreseen campaigns in 2022. Furthermore, TROPOS will use its knowledge to apply the aerosol type separation schemes POLIPHON (developed at TROPOS) and a EarthCARE-like typing scheme (HETEAC-Flex, also developed at TROPOS) to provide a vertically resolved dust-related data set of aerosol over Mindelo, Cabo Verde. TROPOS will additionally  support the development for the new dust product of Aeolus with its expertise in algorithm development and with the heritage obtained during Aeolus Cal/Val activities since launch (WP2000). 

The Royal Netherlands Meteorological Institute (KNMI) is the Dutch national weather service. Primary tasks of KNMI are weather forecasting and monitoring of weather, climate, air quality and seismic activity. KNMI is also the national research and information centre for meteorology, climate, air quality, and seismology. The satellite observation department (RDSW) at KNMI studies the composition and dynamics of the global atmosphere using satellite observations of trace gases, aerosols, clouds, and winds. Satellite data services co-developed within our department include TROPOMI, OMI, Aeolus, GOME-2, SCIAMACHY, SEVIRI, ASCAT, ScatSat-1, HY-2B, and CFOSAT. We are also performing work in preparation for the upcoming EarthCARE, MTG, EPS-SG, CO2M, and third-party scatterometer missions.

The role of KNMI in the project

KNMI will provide support on the aerosol data assimilation experiments that will be conducted (WP5000). Specifically, KNMI will supervise along with NOA the utilization of a data assimilation system based on an Ensemble Kalman Filter from DART that will improve the dust aerosol state of the WRF-L Chem model by assimilating retrieved aerosol dust profiles from Aeolus (L2A+). Several data assimilation experiments will be conducted aiming to exploit the benefits of L2A+ retrievals and assess the potential improvements compare to L2A retrievals.