All files are text files. Most of the files are data files. Some files are meta files (descriptive text).The data files are comma separated value values. Depending on the processing level they may have a header.The data structure in this repository is organized in the following manner:1. All data are sorted into folders by 'scientific activity' number.2. Raw data have the file-naming structure: magnaprobe-transect-date-activity_raw.dat (for example: magnaprobe-transect-20191024-PS122-1_4-1_raw.csv).3. Level 1 data have the file-naming structure: magnaprobe-transect-date-activity-_location.csv. All possible locations are listed in the paragraph below.4. Level 2 location data have same filenames as the Level 1 data, but with added suffixes:a. -track.csv: track with geographic coordinatesb. -track-icecs-yx.csv: track with added local coordinatesc. -track-icesc-xy_corr.csv: track with local coordinates shifted to better correspond the local coordinates of GEM-25. Level 3 data have the file-naming structure: magna+gem2-transect-activity_location.csv.6. In addition, some folders contain text files with activity descriptions. For legs 4-5 there are point-wise comments in the last column of the level 1 data.

At MOSAiC, we collected snow depths by Magnaprobe - an automated snow depth probe, throughout the seasons, most often alongside electromagnetic measurements for deriving total thickness. Most of the data were collected routinely along established transect lines and loops to create timeseries. Some data were collected opportunistically e.g., during 'events'. In addition, several repeated ridge transects were established. During the melt season (June – September 2020), the Magnaprobe was used to measure snow depth, surface scatter layer depth and melt pond depth. This repository includes data obtained by Magnaprobe, sea ice thickness derived by subtracting snow depth from co-located total thickness measurements, a descriptive document including maps (Magnaprobe Repository Description), and a table of with other transect-mode measurements at MOSAiC (Action Log Table): remote sensing instruments, snow structure measurements etc.