Description of Science Operations on HLY1801 Robert S. Pickart Wood Hole Oceanographic Institution Last updated Jan 15, 2018 Outline I. Brief overview of Science: Motivation and goals. Operations: Moorings, CTD, water sampling, net tows, benthic work, underway measurements, additional operations.

There are three science components to the cruise this year

1. The Distributed Biological Observatory (DBO)

The Distributed Biological Observatory (DBO) Occupations of DBO lines since the inception of the program

2. Northern Chukchi Integrated Study (NCIS) Pacific water inflow to the Arctic Ocean

Northern Chukchi Integrated Study (NCIS) Chukchi Slope Current Could carry half of the Pacific Water from the shelf to the basin! Measurements of Chukchi Slope Current from 46 shipboard sections occupied between 2002-2014 (from Corlett and Pickart, 2017)

3. The Ecosystems and Fisheries-Oceanography Coordinated Investigations (EcoFoci) EcoFOCI was established by NOAA in 1984 to study the variability in recruitment success of commercially valuable fin and shellfish in Alaskan waters. Extensive field work (including moorings, CTDs, net tows, ROVs, drifters and towed vehicles) is conducted each year.

The Ecosystems and Fisheries-Oceanography Coordinated Investigations (EcoFoci) Primary Aims Service 28 moorings from the northern Bering Sea to the Chukchi slope Occupy CTD stations Do ~10 Methot tows

The Distributed Biological Observatory (DBO) Primary Aims Occupy DBO lines 2, 3, 4, and 5

Northern Chukchi Sea Integrated Study (NCIS) Primary Aims Carry out a process study investigating the outflow of Pacific water from Barrow Canyon

EcoFoci and DBO-NCIS Tentative Sampling Plan HLY1801 Red dots: EcoFoci Mooring locations Green dots: DBO CTD lines and EcoFoci CTD sites Blue dots: Strawman Barrow Canyon outflow CTD survey

Components of DBO-NCIS Cruise Lead PIs for each group Moorings G. Lebon (on behalf of P. Stabeno) Physical Oceanography CTD R. Pickart Water Sampling from the Rosette C. Mordy, J. Cross, L. Cooper Mesozooplankton and Larval Fish J. Duffy-Anderson Benthos/Sediments J. Grebmeier Underway Measurements R. Pickart, J. Cross Upper Trophics K. Kuletz, Sue Moore Atmospheric Measurements J. Creamean Microbes Eric Collins Manganese V. Oldham Additional Operations J. Cross, L. Trafford, Roy Moffitt Components of DBO-NCIS Cruise Lead PIs for each group

Mooring Operations

Mooring Operations There are 28 moorings total at 13 sites There are 4 types of mooring designs There are 26 recoveries and 27 deployments We will bring our own mooring winch

Mooring Operations (continued) Mooring design 1 “Barrow Deeps”

Mooring Operations (continued) Mooring design 2 “CKIP”

Mooring Operations (continued) Mooring design 3 “CKP”

Mooring Operations (continued) Mooring design 4 “Daft”

CTD Operations

CTD Operations A CTD cast will be done at every station. An MST will run the winch and deck personnel will deploy and recover the package. The STARC team will provide a 1-db averaged downcast CTD file immediately after each cast (using a batch script of Sea-Bird processing routines) Our usual mode of operation is that the science party will be responsible for: --pre-cast set up of the acquisition computer --manning the acquisition computer during the cast and guiding the package to the bottom and back --providing a person on deck to help launch and recover the package if necessary --preparing the package for the next cast

CTD Operations Details Primary System Seabird frame SBE9plus CTD w/ dual temperature (SBE3) and conductivity (SBE4) sensor pairs SBE11plus deckunit Transmissometer Fluorometer altimeter (rated for at least 3000m depth) SBE43 O2 sensor 24-position pylon with 12 liter bottles silicon o-rings Backup Systems Spare 24 x 10 liter package Spare 12 x 30 liter package Computers we will use Healy’s acquisition computer running Sea-Bird's acquisition software. we will provide the computer/software for post-cast processing and in-situ calibration of the CTD data CTD Operations Details

CTD Operations Details Sensor Calibrations It is our understanding that the CTD sensors were calibrated after the 2017 field season, and will be calibrated again after the 2018 field season

Water sample Operations

Water Chemistry After each CTD cast, water samples will be collected from the Niskin bottles on the rosette. On average, the water sampling will take 10-15 minutes and necessitates the use of Hazmat chemicals in the CTD hanger and main lab The Niskin bottles should have silicon o-rings or similar non-toxic o-rings It is our understanding that the 12 L bottles have external springs

Water Chemistry Details 1. Salts We will collect a limited number of salt samples. It is our understanding that the ship has salt bottles and standard water, and that STARC will train one of the science watchstanders to run the autosal 2. Oxygen-18 No special needs 3. Nutrients 4. Dissolved oxygen This requires the use of Hazmats in the CTD hanger and storage in the lab (sodium hydroxide/sodium iodide solution and manganese chloride solution) 5. Chlorophyll This requires the use of a freezer (preferably -80oC)

Water Chemistry Details 5. Dissolved Inorganic Carbon (DIC) and Total Alkalinity (TA) This requires the following: DI dispensing system (18-Ohm) Compressed gas tank storage in the wet lab (ultrapure N2) Functioning fume hood Use of Hazmats in the CTD hanger and storage in the lab (hydrochloric and phosphoric acid, mercuric chloride) 6. Microbes No special needs. 7. Manganese This requires the use of Hazmats in the CTD hanger and storage in the lab (short list goes here).

Zooplankton and Larval Fish Operations

Zooplankton Net Tows Zooplankton multi-net tows will be conducted off the stern using the ship’s spare drum of 0.322 conducting cable (2000m necessary) A Sea-Bird Electronics SBE 49 FastCAT Profiler or SBE 19 SeaCAT will be attached to the wire above the Bongo frame(s) to provide real-time tow data A scientist will be stationed in the lab to monitor the FastCAT and inform the winch operator when the desired gear depth is reached (either 200m or 5-10m above the bottom)

Benthic Operations

Benthic Sampling Two types of benthic sampling will be done: van Veen grabs and Haps coring These will be conducted off the stern using the 9/16 trawl wire Five van Veen grabs and three Haps cores will be done at select “process stations”

Benthic Sampling Details The benthic sampling requires the following: two walk-in climate-controlled rooms at 1oC space in the walk-in refrigerator space in the walk-in freezer deionized water system working

Underway Measurements

Underway Measurements It is our understanding that the STARC technicians will be running the multi-beam during the cruise, and that the Knudson system will be operational as well We will use both the 75 KHz and 150 KHz vessel-mounted ADCPs throughout the cruise. Jules Hummon will monitor the data quality during the cruise. We will use the data in near-real time We will use the underway CTD/pCO2 data and draw samples from the underway seawater line It is our understanding that the meteorological sensors are operational

Atmospheric Measurements

Atmospheric Measurements A suite of sensors mounted on the ship will be used to evaluate aerosol chemistry, biology, and ice nucleating abilities to better understand aerosol sources and impacts on Arctic clouds.

Upper Trophics

Upper Trophics There will likely be two seabird observers and two marine mammal observers on the cruise These observations will be conducted from the bridge

Additional Operations

Additional Operations We will launch 2 AXIB buoys, ~12 SVP-Bs, and ~5 prototype weather stations I. Rigor is the POC SVP-B buoy Prototype weather station AXIB buoy

Additional Operations (continued) We may deploy an UpTemp0 buoy (25m sensor string beneath a buoyant float…no crane necessary) M. Steele is the POC

Additional Operations (continued) We will deploy two ALAMO floats (Argo type floats) P. Stabeno is the POC

Additional Operations (continued) We will launch several satellite-tracked drifters P. Stabeno is the POC

Additional Operations (continued) We will do a calibration exercise adjacent to one or more Saildrones (an autonomous surface vehicle) J. Cross is the POC

Additional Operations (continued) We will do ~10 Methot tows for larval fish (similar procedure to net tows) This is a 2.7 by 2.7 m sq frame with a net that hands back about 5 m and goes into a cod end, similar to that on a bongo. G. Lebon is the POC

Numbers of Stations

There are a total of 53 mooring evolutions There are ~40 EcoFoci/DBO stations and ~60 Barrow Canyon Outflow stations for total of ~100 stations Note: this could change CTD: a single cast at all stations Zooplankton: all DBO stations and roughly every other station otherwise [20 min per station] Benthos: process stations (5 grabs + 3 haps) at all DBO stations and roughly every third station otherwise [50 min per station] 18 day cruise from Nome to Nome, 7-24 August