Air-Sea Interaction Profiler (ASIP)

Scientific objectives behind ASIP:

What is the functional depth distribution of the physical/chemical/biological components at the ocean surface?

Do the species assemblage and/or abundance of neustal organisms influence O2 production and CO2 uptake, and therefore the exchange of gases across the air–sea interface?

To what extent does the interplay of the physical/chemical/biological processes affect each other?

What is the concentration gradient of gases within the ocean surface layer and how much does this affect the determination of the gas fluxes?

What is the quantitative dependence of CO2 air–sea fluxes on the following factors: wind speed,turbulence level, stratification, temperature, salinity, insolation, humidity, precipitation, bubble population, skin effect

Upper Ocean Autonomous Profiling The Air-Sea Interaction Profiler (ASIP) measures several parameters from one platform

Positively buoyant instrument submerged with a thruster

Measurements made during ascent only

Maximum depth 100m

Ascent rate ~ 25 cm/s

Overall length ~ 2 m

Weight ~65 kg

Onboard power 1000Whr from Li-ion batteries

GPS receiver to determine position

Iridium modem for transmitting position and mission parameters

Realtime mission change with iridium SBD (short burst data)

Xenon flasher for nighttime location

ASIP Sensors

Sensors:

- Shear (x2)

- Temperature microstructure

- Conductivity

- PAR

- Fluoresence

- Oxygen

- Pressure

- Video

ASIP Autonomous Profiling

Thruster submerges ASIP to programmable depth

ASIP descends at an angle for profiling in undisturbed water

Thruster controlled by onboard computer

ASIP Autonomous Profiling

Air-Sea Interaction Profiler (ASIP) Shear (x2) to estimate rates of dissipation

Temperature (x2) for microstructure and stratification

Conductivity (x2) for microstructure and density

Air-Sea Interaction Profiler (ASIP) Pressure for a record of depth within the water column

Fluorescence/transmissivity for chlorophyll and

water clarity

Video microscope for high–resolution images of biological species and bubbles

Air-Sea Interaction Profiler (ASIP) Oxygen for chemical gradients in the water

PAR for light absorption in the water column

ASIP during deployment

Profiles over the depth of the mixed layer

Typical mission of 5-minute profiles for 24 hours

Ocean turbulence from shear and temperature microstructure

Chlorophyll from fluorometer (calibrated with shipboard water samples)

Attenuation of light from PAR sensor

Profiles of oxygen