The user community targeted by the current project, named 3P project (PAR for Primary Production) is the one wanting to have robust, complete, user friendly radiative products as inputs for their own specific activities ranging from ecosystem modelling, climate change and carbon cycle monitoring. The goal is to design and distribute a demonstration product from MERIS and potentially Sentinel 3 product with the less assumption on the marine environment and also to deliver with complementary radiative information, ready to use by the user’s model, for example Primary Production model as it will be shown within the project.

However the user’s identification, user’s requirements collection, and users feedback analysis is an entire process that will be addressed specifically in the project with a milestone event being a specific Workshop on PAR and PP being organized in the second year of the project.

Main purposes:

An innovative product, based on robust algorithm basis that has been used for several sensors during the past will be developed for the daily PAR estimation from ENVISAT/MERIS and S3/OLCI and compared to existing in situ data and to Level 3 daily, weekly and monthly equivalent products derived from SeaWiFS, MODIS Aqua and Terra and GOCI. Several original methods for correcting known issues like the diurnal variation of cloudiness will be implemented in a baseline version of the algorithm, and complemented with secondary, experimental quantities like the UV irradiance below or above the sea surface or the spectral PAR. A simple and innovative method will also be developed for assessing the daily PAR uncertainty on a pixel basis. A demonstration data set of one year from MERIS will be disseminated quite early in the project to the user community in order to get their feedback and to draw some recommendations during a workshop that will be organized in the second year of the project. The user’s community will be stimulated by an example of application of this new PAR product to the Primary Production estimation from MERIS and Sentinel 3.