C3S2_620 Improved treatment of the stratosphere in C3S reanalyses

Description

ECMWF, as the Entrusted Entity for the Copernicus Climate Change Service (C3S), invites Tenders for development activities to assess and improve the treatment of the stratosphere in climate reanalyses. This will be achieved by completing developments in the ECMWF Integrated Forecasting System (IFS) and performing assimilation experiments with observations of upper atmospheric temperature and humidity. This work will assess the quality of ERA6 temperature and humidity in the upper atmosphere shortly after production and evaluate a method for correcting model biases in the stratosphere in early periods of future reanalyses using information from the data-rich modern era. To support the validation of these developments, high-quality in-situ observation data records shall be acquired. ECMWF intends to award a single Framework Agreement for a period of maximum 30 months, which shall be implemented via a single Service Contract expected to commence in Q2 2026. Portal instructions: Some of the ITT documents are accessible under the ‘Attachments’ box at bottom right of this page. The full set of ITT documents which are provided inside the response questionnaire are only accessible by registering an interest in this opportunity (see the 'Expression of interest window' at top right). Please refer initially to the ‘ECMWF eProcurement Portal Guidance for suppliers’ file in the Attachments box as this document will help you navigate the portal and locate the necessary information in order to submit a proposal. Please note that the contact email address shown under 'Contact details' is not monitored, and any messages sent to this email address will not be attended to. Questions / clarifications concerning this ITT must be submitted via the Messaging area of the ITT, which can be accessed through the My Activities page of the Portal once you have logged-in and registered your interest in this opportunity. Keywords: reanalyses, C3S, stratosphere