Cross-Archipelago Gradients in Air-Sea Interactions: Sub-Sea Surface Contributions through Upper Ocean Profiling Measurements (PISTON)
Abstract
Our goal is to assess the feedbacks between the atmosphere and ocean with a focus on two distinct time scales: the diurnal and BSISO. Even though these time scales do not overlap, they may influence one another~ the phasing of the BSISO may impact the strength of diurnal cycle in SST and convection; conversely, winds and diurnal modulation of air-sea fluxes may influence BSISO propagation. Subsurface turbulence and flux measurements are proposed for the seas around the Philippine archipelago in the time frame July-September 2018. This region is influenced by atmospheric disturbances associated with Boreal Summer Intraseasonal Oscillations (BSISOs), which are accompanied by deep atmospheric convection, heavy precipitation, and wind bursts of several weeks duration. The proposed time frame and duration (~35- days) will span contrasting scenarios that include both weak and strong surface forcing of the upper ocean. Our work will be conducted in close collaboration with atmospheric components to measure surface and radar meteorology and fluxes, cloud structure, boundary layer turbulence and precipitation. Further, the proposed observations are intended to leverage planned air-land-sea campaigns over the Philippines (Cloud- Aerosol-Monsoon Philippines Experiment – CAMPEX) and the Maritime Continent (Year of the Maritime Continent – YMC). Our goal is to assess the feedbacks between the atmosphere and ocean with a focus on two distinct time scales: the diurnal and BSISO. Even though these time scales do not overlap, they may influence one another– the phasing of the BSISO may impact the strength of diurnal cycle in SST and convection; conversely, winds and diurnal modulation of air-sea fluxes may influence BSISO propagation. Specifically, we will: • quantify the detailed vertical and time-varying structure in both velocity and stratification with emphasis on obtaining high-quality measurements of the upper 10 m of the ocean, which includes the diurnal warm layer, • quantify sea surface cooling rates due to wind-wave mixing and diurnal cooling, • quantify sea surface cooling rates due to shear instability with the ultimate goal of estimation of Ri and other bulk parameters for parameterization of shear-driven mixing, • quantify sea surface heating rates (from both above and below) in thin nearsurface fresh layers deposited by convective precipitation, combine the above to assess feedbacks between the upper ocean heat budget and atmospheric convection. To accomplish these objectives, we propose to work within the PISTON DRI to instrument a global class research vessel to 1. measure turbulence and stratification in the upper 1-10 m using newly-developed techniques for near-surface temperature, salinity, and turbulence, 2. measure turbulence and stratification in the upper 5-250 m at rates of 6-10 profiles/h with our turbulence profiler, Chameleon, 3. measure current profiles in the upper 2-20 m with a side-mounted acoustic Doppler current profiler (ADCP), 4. measure current profiles in the upper 15-750 m with hull-mounted ADCP, 5. image fluid flow fields with stem-mounted high-frequency (120 kHz) echosounder, 6. measure sea surface temperature (nominally a few centimeters depth) with a seasnake, 7. use X-band radar for front detection and propagation (freshwater lenses deposited by local precipitation).
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Nov 23, 2016
- Source ID
- N000141613085
Entities
People
- James N. Moum
Organizations
- Office of Naval Research
- Oregon State University
- United States Navy