Southern Boundary Region of the Winter Anomaly in Ionospheric Absorption in Winter 1971/72 Observed on Board the Cargo Vessel "Hanau" of Hapag-Lloyd Moving between 10 Degrees and 55 Degrees N

on board a cargo vessel (mv "Hanau" of Hapag 0 0 0 0 -Lloyd) moving between Hamburg (53 N; measurements of absorption were made at various other locations and the data used as a basis for comparison [circuits Norddeich-Lindau 0 0 0 0 (A3;