The GCOS Science Day has been introduced in 2015 as a platform to present the work of the GCOS programme to the national and regional experts, but also to inform Steering Committee members and panel experts on the scope and capacity of the resident scientists, policy officers and observation experts.  Ideally, the objective is the establishment of national GCOS Science days  which would call in the national and regional exerts on a regular base, foster exchange of knowledge  and strengthen coordination on a local level.