Sodemann, Harald; Seidl, Andrew Walter; Thurnherr, Iris; Dekhtyareva, Alena; David, Robert Oscar; Carlsen, Tim; Chandler, David M; Schäfer, Britta; Gjelsvik, Astrid Bragstad; Touzeau, Alexandra; Zannoni, Daniele; Baumgartner, Gerd; Storelvmo, Trude; Wieder, Jörg; Kanji, Zamin A; Flügge, Martin (2025): ISLAS2021: Calibrated stable water isotope measurements and aerosol measurements at the coast of northern Norway during March 2021 [dataset bundled publication]. PANGAEA, https://doi.org/10.1594/PANGAEA.984616

During a 2-week measurement campaign from 15-31 March 2021 (ISLAS2021), we collected a comprehensive dataset characterizing the atmospheric water vapour and precipitation stable isotope and aerosol composition at a coastal station in the European sub-Arctic. Located at the northeastern coast of the Nordic Seas, stable water isotope measurements with cavity ring-down spectrometers (CRDS) were collected at Andenes, Norway close to sea level and at the nearby ALOMAR mountain top observatory at 370 m a.s.l. Paired water vapour isotope and precipitation measurements at sub-event time resolution were collected at both station locations. These were supplemented with water vapour isotope measurements at the cities of Tromsø, Norway and Bergen, Norway. Surface precipitation samples were collected on a per-event basis along a transect towards the south to assess spatial representativeness. Measurements of ice nucleating particle concentrations were taken at sea level during precipitation events, supplemented by continuous size-resolved aerosol measurements. These detailed measurements were complemented by additional instrumentation to characterize the atmospheric conditions, including ground-based vertical-pointing rain radars, disdrometer, frequent radiosonde ascents and a ceilometer. All stable water isotope measurements have been calibrated onto the VSMOW-SLAP scale. During the campaign, weather conditions were alternating rapidly between warm mid-latitude air masses and marine cold-air outbreak conditions. The data from the ISLAS2021 measurement campaign therefore provide insight into a variety of mixed-phase precipitation processes, atmospheric long-range transport, and the dynamics of high-latitude weather system with the combined perspective of stable water isotopes and aerosol measurements.