Total Sky Imager observations in the visual and infrared on Polarstern cruise PS149 and PS150 (CONTRASTS and EGC-Sources)

A Total Sky Imager (TSI) camera recorded cloud cover in the visual and infrared during Polarstern cruises PS149 and PS150 from July to October 2025 in the Arctic Ocean. The TSI was mounted on the bow-facing reling of the Observation Deck, where it recorded an image every minute. The setup consists of the Mobotix visual fish-eye sensor Mx-O-SMA-S-6D016-X with 180° angles in both directions, 3072 x 2048 pixels, focal length of 1.6 mm and an aperture of f/2.0, as well as the infrared sensor Mx-O-SMA-TS-R079. The infrared sensor operates in the IR range of 7.5 to 13.5 𝜇m, with angles of 45° and 35° and 336 x 252 pixels. For temperatures below −40 °C, i.e., in clear sky conditions, the TSI did not take pictures continuously after 250912. The ship's crow's nest covers a large section of the fish-eye camera's field of view, and one of the ship's antenna is partially in the infrared camera's field of view over the whole time period. For the infrared images, only colored plots set on a fixed color scale from 310 to 400 with no physical meaning or unit could be saved. The pictures can be downloaded as daily zip files. Data are available from 25-07-04 08:07 to 25-10-17 08:13, with gaps at 2507090404 - 2507121651, 2508191151 - 2508201022, and 2508301547 - 2508301702.