Radiation closure experiments for EarthCARE validation (RACE-ECV)

• Unité de recherche: SEFRI
• Numéro de projet: P2024-PMOD RACE-ECV

Mots-clé (Anglais)

PMOD EARTHCARE STELIOS KAZADIS SEFRI SBFI SERI ARF SSO

Description succincte (Anglais)

EarthCARE, is a new ESA atmospheric satellite mission that will be launched in May 2024. ESA supports a number of EarthCARE related Cal/Val activities, among which the ACROSS activity that aims to organize field experiments in the Mediterranean region focused on EarthCARE validation. ACROSS lacks the deployment of high-accurate photometric suites in synergy with other ground-based remote sensors. Radiation measurements on the other hand, are vital for EarthCARE, since the missions’ objective is to constrain radiative fluxes calculations at the top and bottom of the atmosphere within accuracies of 10 W/m2.
EarthCARE atmospheric products (e.g. aerosol and cloud related ones) and radiative transfer codes are used in developed (not fully evaluated) algorithms in order to retrieve solar radiation at the surface and at the top of the atmosphere (outgoing radiation). Such parameters are vital for the earth-atmosphere balance and climate research, as this incoming vs outgoing radiation is the measure of radiative effects on climate. In order to provide a detailed evaluation of the atmospheric input used and also for the proposed radiation transfer related algorithms, atmospheric (e.g. aerosols) and solar spectral radiation measurements are needed at the surface.
PMODWRC is the World solar radiation center (defined by the World Meteorological Organization (WMO) as the world reference institute for solar measurements and aerosol optical depth) and after an initial invitation by ESA to participate in EarthCARE Cal/Val activities, it is proposed that PMODWRC in collaboration with Un. Of Zurich (UZH) will join the ACROSS activity that is central for the mission cal/val. ACROSS will be deployed in the Mediterranean. Intensive Observation Periods are foreseen for spring of 2025 and 2026 where solar radiation and aerosol instrumentation from PMODWRC and UZH will participate, and analysis of the results will help towards radiation closure experiments that include verification of EarthCARE products and also radiative transfer related algorithms.
This proposal has been submitted and accepted from ESA, confirming the interest and value of the Cal/Val programme of observations and analysis proposed and was considered accepted as an important element of the EarthCARE Cal/Val activities.

Objectifs du projet (Anglais)

The objectives of the Swiss participation in the ACROSS experimental campaigns through the proposed “Radiation closure experiments for EarthCARE validation” (RACE-ECV) project are:
1. to perform a thorough validation of the EarthCARE stand-alone aerosol and cloud products employing sophisticated ground-based remote sensors; and to directly validate EarthCARE products related with total column multi-wavelength aerosol and cloud optical thickness.
2. to perform radiative closure studies through intercomparisons with high-quality solar irradiance measurements at the surface (ground-based actinometry) and at TOA (space-borne radiometers, including EarthCARE Broadband radiometer (BBR)); utilizing the validated aerosol and cloud products in Radiative Transfer Model (RTM) simulations.
3. To provide a high quality measurement dataset consisting of aerosol optical properties and also spectral solar radiation (direct and diffuse components), in order to be used synergistically within ACROSS science groups, towards various atmospheric studies and link the results with new EU projects dealing with aerosol-cloud interactions (e.g. CERTAINTY).