naa a22 4500 510754074 CHVBK 20180411083116.0 cr unu---uuuuu 180411e20130301xx s 000 0 eng 10.1007/s13131-013-0292-6 doi (NATIONALLICENCE)springer-10.1007/s13131-013-0292-6 A theoretical study of the multigrid three-dimensional variational data assimilation scheme using a simple bilinear interpolation algorithm [Elektronische Daten] [Wei Li, Yuanfu Xie, Guijun Han] In order to solve the so-called "bull-eye” problem caused by using a simple bilinear interpolation as an observational mapping operator in the cost function in the multigrid three-dimensional variational (3DVAR) data assimilation scheme, a smoothing term, equivalent to a penalty term, is introduced into the cost function to serve as a means of troubleshooting. A theoretical analysis is first performed to figure out what on earth results in the issue of "bull-eye”, and then the meaning of such smoothing term is elucidated and the uniqueness of solution of the multigrid 3DVAR with the smoothing term added is discussed through the theoretical deduction for one-dimensional (1D) case, and two idealized data assimilation experiments (one- and two-dimensional (2D) cases). By exploring the relationship between the smoothing term and the recursive filter theoretically and practically, it is revealed why satisfied analysis results can be achieved by using such proposed solution for the issue of the multigrid 3DVAR. The Chinese Society of Oceanography and Springer-Verlag Berlin Heidelberg, 2013 multigrid nationallicence three-dimensional variational nationallicence data assimilation nationallicence bilinear interpolation nationallicence Li Wei Key Laboratory of State Oceanic Administration for Marine Environmental Information Technology, National Marine Data and Information Service, State Oceanic Administration, 300171, Tianjin, China aut Xie Yuanfu NOAA Earth System Research Laboratory, 80305-3337, Boulder, CO, USA aut Han Guijun Key Laboratory of State Oceanic Administration for Marine Environmental Information Technology, National Marine Data and Information Service, State Oceanic Administration, 300171, Tianjin, China aut Acta Oceanologica Sinica The Chinese Society of Oceanography 32/3(2013-03-01), 80-87 0253-505X 32:3<80 2013 32 13131 https://doi.org/10.1007/s13131-013-0292-6 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s13131-013-0292-6 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Li Wei Key Laboratory of State Oceanic Administration for Marine Environmental Information Technology, National Marine Data and Information Service, State Oceanic Administration, 300171, Tianjin, China aut NATIONALLICENCE 700 1- Xie Yuanfu NOAA Earth System Research Laboratory, 80305-3337, Boulder, CO, USA aut NATIONALLICENCE 700 1- Han Guijun Key Laboratory of State Oceanic Administration for Marine Environmental Information Technology, National Marine Data and Information Service, State Oceanic Administration, 300171, Tianjin, China aut NATIONALLICENCE 773 0- Acta Oceanologica Sinica The Chinese Society of Oceanography 32/3(2013-03-01), 80-87 0253-505X 32:3<80 2013 32 13131 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer