This dataset contains physical, chemical, and biological data collected during research cruises for the Hanna Shoal Ecosystem Study. The study occurred at 138 stations in the Hanna Shoal area of the Chukchi Sea in August of 2012 and 2013, and involved sensor measurements and sampling of water, sediment, and biota conducted by investigators from several universities and research organizations. The dataset includes more than 50,000 data values across 200+ variables, 400+ taxonomic names, 30+ collection methods, and 30+ lab analysis methods. Seawater samples include variables such as salinity, chlorophyll a, particulate organic carbon, total suspended solids, and dissolved oxygen. Samples from the benthic zone include variables such as taxonomic counts, biomass, organic contaminants, and stable isotopes. Sediment samples include variables such as hydrocarbons, metals, grain size distribution, oxygen uptake, and carbon to nitrogen mass ratio. All samples include numerical data value, date of sample collection, location in latitude and longitude coordinates, station identifier, sampling method, and the researcher responsible for the measurement. Furthermore, these data were harmonized according to a community driven set of controlled vocabularies for variable names, chemical speciations, units of measure, sample mediums, and sample types maintained by the Consortium of Universities for the Advancement of Hydrologic Science, Inc. The data are accompanied by an entity relationship diagram and data dictionary explaining the data structure.

A 35-day NSF-sponsored cruise aboard the USCGC Polar Star has studied in depth the physical oceanography of the Chukchi Borderland and Mendeleev Ridge regions. An extensive hydrographic survey (126 CTD casts) was conducted. In addition to CTD profiles of temperature, conductivity, oxygen, and light scatter and L-ADCP profiles of water velocity, bottle samples were taken for nutrients (2662 samples), dissolved oxygen (2999 samples), salinity (3066 samples) and tracers CFCs (F11, F12, F113, ca. 2500 samples), O18 isotopes (ca.1000 samples), Barium (ca.1000 samples), Helium (ca.108 samples), Iodine-129 (96 samples) and Cesium-137 (27 samples). Twenty-one denitrification (N:Ar ratio) samples were also taken. A total of 47 XBTs were used both to increase spatial coverage over the shelf and to increase spatial resolution in the slope regions. To better map the boundary current regime, 3 oceanographic moorings carrying current meters and temperature and salinity sensors were deployed across the boundary current for the ca. 1 month duration of the cruise. During the cruise, via a website of daily updates from a High School teacher aboard the Polar Star and visits to schools in Barrow, we brought Arctic research into the classroom. Post-cruise a multi-institute team of scientists will study this extensive data set, with reference to previous (sparse) measurements, Canadian measurements taken this year in the Canadian Basin and near Northwind Ridge, and modeling results, to understand the role of this Arctic Crossroads in the circulation of the Arctic Ocean.

These data are part of a multi-year baseline environmental studies data set collected as part of the permitting process prior to drilling exploration wells. The objectives of the Chukchi Sea Environmental Baseline Studies Program are: 1. To provide data for pre-exploration and development-related activities 2. To provide data for permit applications 3. To provide input to planning of future operations and associated mitigation 4. To provide additional baseline data that can be used to assess and measure the potential environmental effects of offshore oil and gas exploration and development in the northeastern Chukchi Sea. These data were submitted under Annex 1 of the Memorandum of Understanding between NOAA and the oil companies (NOAA Agreement NOS-MOA-2011-080).

The Conductivity, Temperature and Depth (CTD) and other data were collected in Chukchi Sea. Data was collected from Ship ALPHA HELIX. The data was collected over a period spanning from September 21, 1992 and October 4, 1992. Data from 107 casts was submitted in one diskette by Dr. Chirk Chu of Institute of Marine Science, University of Alaska, Fairbanks, AK. Data has been processed and is available in F022-CTD-Hi Resolution file format of NODC. F022 High-resolution CTD data is collected from high resolution (conductivity-temperature-depth) instruments. As they are lowered and raised in the oceans, these electronic devices provide nearly continuous profiles of temperature, salinity and other parameters. Data values may be subject to averaging or filtering or obtained by interpolation and may be reported at depth intervals as fine as 1 m. Cruise and instrument information, position, date, time and sampling interval are reported for each station. Environmental data at the time of the cast (meteorological and sea surface conditions) may also be reported. The data record comprises values of temperature, salinity or conductivity, density (computed sigma-t) and possibly dissolved oxygen or transmissivity at specified depth or pressure levels. Data may be reported at either equally or unequally spaced depth or pressure intervals.

This dataset contains water temperature, salinity, currents, marine chemistry, biology, geology, and underway meteorology taken by CTD, LADCP, and other instruments in the Bering and Chukchi Sea from the research vessel Xiangyanghong 01 from 2019-08-24 to 2019-09-08. Data were collected during the CHINARE 2019 Arctic expedition, including work performed in the US EEZ. Data are in text, xls, csv formats. Data report is in pdf. CTD data are in the SeaBird HEX format, processed CTD are in CNV format. ADCP data are in the Teledyne RD Instruments binary format (*.0000), processed ADCP are in NetCDF. This dataset is U.S. State Department MSR U2019-020 as part of the World Data Services for Geophysics and Oceanography.

Surface current velocities representative of the upper 2 m of the water column were collected in the northeastern Chukchi Sea using high-frequency radar systems during the ice free seasons of 2012 - 2014. Hourly data from August through October of each year are included at a spatial resolution of 6 km.

Drifters were deployed from vessels in the Chukchi Sea during the ice-free seasons of 2011-2013. Drifter positions were determined via GPS, and positions were relayed via Iridium communications to on-shore data centers. Drifters were tracked from their release until they a) were picked up at sea for redeployment; b) beached on-shore; or c) died at sea because of battery failure or other causes. Many drifters remained active as sea ice re-formed in the region, and 3 drifters were frozen in the ice and released the following spring. Drifters also recorded Sea Surface Temperature (SST) from 2012 onward. Drifters were of various types (Davis, SVP, and Microstar) and were drogued at various depths (1 m and 10 m).

The ChukSA climatology is comprised of shipboard acoustic Doppler current profiler (SADCP) ocean velocity datasets collected by research vessels while working in, or transiting through, the Chukchi Sea region. SADCP datasets included in the climatology have received high- level post-processing, including manual editing and removal of estimated barotropic tides, and have been combined into a unique dataset of direct ocean velocity measurements. As of early 2023, ChukSA includes 95 datasets from 57 cruises by six ships spanning 16 years since 2002. To create the ChukSA climatology, the creators searched for SADCP datasets with cruise tracks that fell within the specified region of 65°-75° N and 170°-150° W. This was done by contacting colleagues and researchers who regularly work in the Chukchi region and by reaching out to the UNOLS Rolling Deck Repository (R2R) team, which archives cruise metadata and data from research vessels, to collect SADCP datasets from research missions as well as transits. Please see below for the original dataset citations and acknowledgements. The original datasets identified were retrieved in a variety of formats (from varying SADCP systems/manufacturers), with a wide range of post-processing completed. Frank Bahr (Woods Hole Oceanographic Institution) reviewed each dataset identified and assessed the need for post-processing. When necessary, appropriate post-processing methods were applied to datasets to ensure that all entries in the climatology were appropriate for climatological analysis. Post-processing methods are summarized in 'ChukSA_readme_final.pdf', with extensive details for each dataset available in a separate document titled ‘ChukSA_Appendix_A.pdf’. Final velocity measurements included in ChukSA are high quality and ready for use by the community. Data are in NetCDF.