AUTHOR=Hutt A. , Bocquet M. , Carrassi A. , Lei L. , Potthast R. TITLE=Editorial: Data Assimilation of Nonlocal Observations in Complex Systems JOURNAL=Frontiers in Applied Mathematics and Statistics VOLUME=7 YEAR=2021 URL=https://www.frontiersin.org/journals/applied-mathematics-and-statistics/articles/10.3389/fams.2021.658272 DOI=10.3389/fams.2021.658272 ISSN=2297-4687