This study focused on the synergistic retrieval of cloud information from active and passive observations. While this synergistic approach is well established for precipitation, it is used less for clouds.

The objective of the Aeolus/EarthCARE Aerosol Assimilation Studies (A3S) project was to allow assimilation of the Aeolus L2A lidar backscatter data, also paving the way for the assimilation of EarthCARE products. Since the Aeolus and EarthCARE missions were not yet launched at the time of the study, demonstration datasets based on model data (MOCAGE model for the aerosols and the IFS for the clouds) and a one-day dataset based on CALIPSO data (reprocessed at the UV wavelength and with the Aeolus orbit data) was created.

The basic goal of this project was to analyse how the usage of non-conventional data (i.e. 'data of opportunity') in conjunction with conventional data could help improve the estimation of parameters for weather and space weather. Conventional data it is considered to be data coming from well-known sources such as permanent GNSS receivers (e.g. receivers from IGS or EUREF networks) while non-conventional data is considered to be GNSS data from research vessels or mass-market GNSS receivers (such as smartphones or other single-frequency GNSS chipsets).

The main objectives of this project were to develop the tools and structure to enable routine EarthCARE radar and lidar observations of clouds to be assimilated in the ECMWF Numerical Weather Prediction model and to prepare for the real-time monitoring of the observations to detect instrument degradation or errors. This required adjustments of assimilation tools, such as the observation operators, observation error definition, quality control, data screening and bias correction.

The Process Exploration through Measurement of infrared and millimetre-wave Emitted Radiation (PREMIER) instrument was proposed to ESA within the framework of the 7th Earth Explorer Call. The instrument was designed to quantify dynamic, radiative, and chemical processes in the upper troposphere and lower stratosphere (UTLS) that control the global atmospheric composition.

The ISOTROP project was a response to the ESA ITT "Impact of Spaceborne Observations on Tropospheric Composition Analysis and Forecast", AO/1- 6845/11/NL/AF. The general aim is to assess the benefit of the LEO+GEO satellite system for the understanding of local to regional scale tropospheric composition with a focus on Europe. The ISOTROP consortium involved researchers from the European institutes CNRS-GAME, TNO, NILU, FMI, and was led by KNMI.

The study relied on various state-of-the-art numerical tools (RT model, assimilation OSSE and NWP forecast systems) to explore the possible impact of a Geosounder mission on the retrieval of humidity and forecast. The study showcases that some specifications are valid for such an endeavor and some needs to be refined. Future works should be directed towards a more complex information content analysis with an all sky OSSE set up and maybe a multispectral/hyperspectral perspective on the channel selection.

This summary presents the work by the University of Strathclyde, SCISYS and Roke Manor Research in response to the ESA SysNova Challenge AO7891; Remote sensing with cooperative nanosats, Challenge #3 – Weather. The objective of this work was to evaluate the performance and cost of multi-agent satellite networks capable of providing data in support of severe weather monitoring.

Ambient space plasma can induce electrostatic noise in a linear antenna onboard a spacecraft. The resulting quasi-thermal noise (QTN) intensity spectrum as a function of frequency depends on the plasma parameters. The phenomenon can be utilised for inferring the plasma parameters if one measures the induced noise by a sensitive radio receiver. This is called QTN spectroscopy and it has been demonstrated and validated in several space missions that the technique is able to uncover the correct plasma parameters.

The SIROCCO study was performed under ESA guidance by a consortium led by NOVELTIS and including four partners: ULB (Belgium), IASB-BIRA (Belgium), SRON (Netherlands) and IAPS (Italy). The goal of the study was to review in a multidisciplinary context (Earth Observation and Planetary Science) the status of existing retrieval algorithms and to extend their capabilities when applied to remote sensing data collected (or to be collected in the near future) by instruments in orbit around the planets Earth and Mars, with atmospheric carbon monoxide (CO) and methane (CH4) as specific targets.