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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?
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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
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