AT32

Ship

Cruise Party

Departure: Nov 6, 2015

Arrival: Dec 1, 2015

Operations Area

Science Objectives

The North Atlantic Aerosols and Marine Ecosystems Study (NAAMES) is an interdisciplinary investigation addressing two primary science goals: (1) Define environmental and ecological controls on plankton communities and (2) Define linkages between ocean ecosystem properties and biogenic aerosols. Within these two broad goals, the NAAMES investigation focuses on identifying environment-ecosystem-aerosol interdependencies in the climate-sensitive North Atlantic. This ocean region hosts the largest annual plankton bloom in the global ocean and its impact on Earth’s radiative balance is particularly sensitive to biogenic aerosol emissions. Specific baseline science objectives of NAAMES are to (1) Characterize plankton ecosystem properties during primary phases of the annual cycle in the North Atlantic and their dependence on environmental forcings, (2) Determine how primary phases of the North Atlantic annual plankton cycle interact to recreate each year the conditions for an annual bloom, and (3) Resolve how remote marine aerosols and boundary layer clouds are influenced by plankton ecosystems in the North Atlantic. These objectives are accomplished by coupling autonomous in situ and satellite measurements sustained throughout the NAAMES investigation with short-term, coordinated ship and airborne campaigns that target critical events in the annual plankton cycle and focus on detailed system characterization. These direct observations are integrated with climate-ecosystem modeling to create a process-based understanding that allows improved interpretation of historical data records and improved predictions of future change.

Science Activities

The NAAMES investigation has a duration of 5 years and involves 4 field campaigns.  Each field campaign will share a common observation profile.  The first campaign will occur in November 2015 and will involve the UNOLS R/V Atlantis.  For each campaign, ship-based measurements will be accompanied by aircraft measurements.  The aircraft will be a NASA C-130 stationed either from Saint John’s Bay, Canada, or the Lajes Field in the Azores. Global Class Research Vessels, such as the Atlantis, are required for each field campaign due to requirements for foreward deck space for a full-sized aerosols van, deck space for a radioisotope van, and the large scientific complement (34 berths).  A global class vessel is also advantageous for the NAAMES project on account of sea-worthiness during field studies that span the annual cycle.

Each field campaign involves a 26-day, roughly triangular-shaped ship transect (see uploaded files on transect and stations). The ship’s direction around the transect triangle is scientifically irrelevant, allowing real-time adjustments based on prevailing and forecasted weather conditions and sea-states. Assuming a counterclockwise direction, the ship proceeds from Woods Hole to the turning point at 40° N. During this outbound leg, underway sampling is conducted, but not regular overboard deployments.  It would be very beneficial to make at least one stop during the outbound transect to conduct a ‘shake-down’ station of overboard operations.  Following the turn northward, the full complement of ship-based measurements begins and continues until the northern-most turning point (~55° N). During this primary latitudinal science leg, daily operations involve a sampling station that begins near dawn and then continues until ~11:00.  Station operations will include multiple CTD/Rosette casts, the first of which will be relatively shallow casts (~200 m), followed by a deep cast to ~2000 m.  Optical and other instruments mounted on the rosette for the shallow casts but with depth limits <2000 m will need to be removed before the deep cast.  Following the deep cast, an additional shallow cast will be conducted for final water sampling and underwater light measurements.  Also during station, measurements will be made of downwelling light properties and water leaving radiances.  In addition to daily station occupations, 2 stations will be chosen for long-term measurement series (36-48 h).  During the long-term stations, a surface lagrangian drifter will be deployed upon arrival at station and then measurements will be conducted over the following occupation while following the trajectory of the drifter.  This approach minimizes the impacts of advective processes on measured system changes over the long-term station. Once the primary science transect is complete and the northern-most turning point is reached, the return transect will commence, with continuous in-line measurements conducted until the day before port arrival, but no additional station occupations anticipated.

In addition to water sampling and flow through seawater measurements, another key component of the NAAMES investigation is the measurement of aerosols.  For this aspect, key measurements will be conducted from the Aersosols Van, located on the forward deck of the ship.  Aerosol measurements are conducted continuously while the wind is from the forward direction. These measurement have to be terminated when the wind is from the backward direction, due to contamination from the ship.  Thus, it is desired to keep the ship orientation favorable for aerosol samples for the greatest fraction of the time feasible (understanding that ship orientation during overboard castings is dictated by sea state and wire angle). 

Also during the field campaigns, deployments will be made of five autonomous profiling floats and surface drifters.  Deployments will occur along the N-S primary latitudinal science transect, with exact location dependent on station location and real-time information on regional mesoscale eddies.  Surface drifter deployments will target mesoscale eddy centers and will provide water parcel tracking capabilities that inform flight patterns for the C-130.   

Airborne deployments accompanying the ship measurements will focus on the primary N-S latitudinal transect.  The airborne measurements include in situ aerosol sampling and remote sensing measurements with a hyperspectral ocean color sensor, a high resolution lidar, a polarimeter, and a downwelling irradiance sensor.  Aircraft measurements need to be highly coordinated with the ship, so regular communications between the two platforms is essential.  The NAAMES team gained considerable experience conducting successful ship-aircraft campaigns during the previous 2012 Azores campaign and the 2014 SABOR campaign.  Aircraft measurements begin shortly after takeoff, and continue during the transect to the ship.  Once arriving at the ship, a diversity of flight patterns are followed to characterize horizontal and vertical variability in ocean ecosystem and aerosol properties.  The aircraft transect will also include fly-overs of regions previously sampled by the ship, as tracked by the surface drifters.  These drifters essentially provide a ‘bread crumb trail’ that allows the aircraft to follow changes in system properties well after the ship has departed a given sampling station.  One the primary science measurements are complete along the ship transect, the aircraft returns to base.

Additional Info

Stations:

Supporting documentation:

Shipboard Equipment

Shipboard Communication

CTD/Water Sampling

Critical CTD Sensors

Hydrographic Analysis Equipment

MET Sensors

Sample Storage

Navigation

Navigation

Winches

Standard Oceanographic Cables

Portable Vans

Specialized Deck Equipment

Over the Side Equipment

Special Requirements

Additional Cruise Items/Activities

Hazardous Material

Radioactive Material

Additional Information

Both aerosol vans are 20’x8’x8’ shipping containers.  The 1^st is owned by Scripps and will contain atmospheric particle measurements (possibly including Meskidhze's instruments and sampling).  The 2^ndaerosol van is to be requested from UNOLS for atmospheric gas measurements.  Preferred mounting is on feet or rails 2’ above deck.  We'll need 2 stair steps for each if available.  It is prefer if both aersol vans are both mounted as far forward as possible and as close to each other as possible. 

For the Scripps van, power requirements are 120 amps “clean” continuous power at 110 VAC.  Lynn Russel will provide a 408 transformer. For the UNOLS supplied van, power requirements are  25 amps "clean" power and 14.1 amps dirty power at 110 VAC.  The UCSC team has an additional 11 amp clean + 11 amp dirty power requirement for their mass spectrometer, but where this souce is depends on where the instrument is located (i.e., either in the van or wet lab).  A crane is required to load van (15000 lb) onto “feet” bolted to 02 deck.  A crane is again required to load inlet (300 lb) on top of van while it is secured.  Two gas cylinders (dry air, standard size) need to be secured external to van (request a 2x2 rack be mounted on deck adjacent to back of van).

We would also like to request, if possible, phone installation in the Scripps van (the use of walkie talkies is not advised as they interfere with the mass spectrometers in the van)

Checklist

United States (Woods Hole, MA)

Checklist