We report continuous observations in the high Arctic (north of 84°N) over the full 2013 summer season at two nearby sites with distinct initial snow depth, ice thickness and altitude with respect to the local ice topography. The two sites subject to similar atmospheric conditions that did not favor strong ice melt showed a contrasted evolution. One site, with an initial thin sea ice (1.40 m) at a low location of the floe, witnessed the formation of a spectacular 1.20 m-deep melt pond, a pond-enhanced erosion of the ice surface and a sudden pond drainage into the ocean. Then, the outpoured fresh water rapidly froze, heated the old ice from below and also acted as a temporary shield from the ocean heat flux while it was progressively ablated through dissolution. Eventually, the site almost recovered its initial ice thickness. In contrast, the other site, with an initial thicker sea ice (1.75 m) at a high location of the floe, did not support any significant melt water and underwent over 0.5 m of continuous basal ablation. The two sites witnessed formation of superimposed and interposed ice. Sea-ice survived summer melt at the two sites which entered the refreezing season with similar snow and ice thicknesses. For the first time, processes associated with the formation of a deep melt pond and subsequent false bottom evolution are continuously documented with ice mass balance instruments.  Important Note: This submission has been initially submitted to SEA scieNtific Open data Edition (SEANOE) publication service and received the recorded DOI. The metadata elements have been further processed (refined) in EMODnet Ingestion Service in order to conform with the Data Submission Service specifications.

This dataset is included the following parameters: water temperature, sound velocity in the water body .

Gridded fields of salinity for 50 N - 67 N, 41,5 W - 61,5 W geographic region (yearly, 2000 - 2016), 29 standard depths

Results of measurements of the CO2 flow from water from various depths using the bathometers of the oceanographic station No. 67 on the 26th cruise of the research vessel "Akademik Fedorov" Numerical results of measurements of the IR gas analyzer. Parameter:chamber temperature,atmospheric pressure inside the optical element of the gas analyzer,concentration of water vapor inside the chamber, CO2 concentration inside the chamber, CO2 concentration inside the chamber, corrected for water vapor, relative humidity inside the chamber, water salinity by bathometer, water sampling temperature by bathometer, water temperature before measurements, water temperature after measurements.

Measurement data on the "Rossiya" icebreaker.This dataset is included the following parameters:temperature of water,salinity,dencity.Additionally, meteorological data are presented:wind speed,wind direction, air temperature, visibility.

Surface Ocean CO2 Atlas (SOCAT)

The cruise HM 2015617 onboard the Research Vessel Håkon Mosby is the second and last research cruise of the project ”On Thin Ice (NICE): Role of Ocean Heat Flux in Sea Ice Melt”. NICE is led at the Geophysical Institute, University of Bergen (PI: Ilker Fer) and is funded by the Research Council of Norway (project number 229786) for the period 01.01.2014-31.12.2017

This dataset is included the following parameters: water temperature, salinity,air temperature,visibility (code). Research vessel:"Mikhail Somov".

A mooring, equipped with a CTD sensor (SBE37) at 350 m depth, was deployed in the Yermak Pass on the 24 September 2017 from the R/V Lance. The mooring was recovered in summer 2020 from K/V Svalbard. The present dataset provides 10-day smoothed time series of daily conservative temperature (CT, °C), absolute salinity (SA, g/kg) and pressure (db) recorded by the SBE37 sensor, from the 24 September 2017 to the 31 May 2020. The mooring was located at 80.63°N, 6.88°E. Important Note: This submission has been initially submitted to SEA scieNtific Open data Edition (SEANOE) publication service and received the recorded DOI. The metadata elements have been further processed (refined) in EMODnet Ingestion Service in order to conform with the Data Submission Service specifications.

Results of measurements of the CO2 flow from water from various depths using the bathometers of the oceanographic station No. 69 on the 26th cruise of the research vessel "Akademik Fedorov" Numerical results of measurements of the IR gas analyzer. Parameter:chamber temperature,atmospheric pressure inside the optical element of the gas analyzer,concentration of water vapor inside the chamber, CO2 concentration inside the chamber, CO2 concentration inside the chamber, corrected for water vapor, relative humidity inside the chamber, water salinity by bathometer, water sampling temperature by bathometer, water temperature before measurements, water temperature after measurements.