Project CLIMODE - CLIVAR Mode Water Dynamic Experiment

Sponsors

Principal funding is provided by the National Science Foundation.

This material is based upon work supported by the National Science Foundation under Grant No. 0424536.

Research

The CLIMODE surface mooring will quantify the air-sea exchange that is responsible for the buoyancy loss that forms subtropical mode waters.

Measurements from the buoy will provide accurate estimates of the sensible, latent, and radiative heat fluxes, which will be combined to compute the net heat flux. The net heat flux will then combined with estimates of the net freshwater flux to compute the buoyancy flux. Finally, the variation of the buoyancy flux integrated across isopycnals at the ocean surface is used to compute transformation rates.

Obtaining accurate air-sea heat and freshwater fluxes and precise estimates of their gradients are crucial if we are to better understand and model the formation of eighteen detree water (EDW) and the evolution of upper ocean structure in the EDW formation region.

There are large uncertainties in air-sea fluxes obtained from climatological data, atmospheric models, and remote sensing techniques. In CLIMODE for the first time we will accurately quantify the magnitude of the fluxes, their temporal and spatial variability, and their role in EDW formation.

Moorings

The 2.7m Modular Buoy is equipped with meteorological instrumentation including two complete sets of Air-Sea Interaction Meteorological (ASIMET) systems, measuring air and sea surface temperatures, relative humidity, barometric pressure, wind speed and direction, incoming shortwave and longwave radiation, and precipitation.

Complete surface meteorological time series is recorded every minute, as necessary to compute air-sea fluxes of heat, freshwater and momentum. Each ASIMEt system also transmits hourly averages of the surface meteorological variables via the Argos satellite system.

The mooring also carries Nortek current meters, and conductivity, salinity and temperature recorders located in the upper 600 meters of water. The mooring line is instrumented in order to collect accurate time series of surface forcing and upper ocean temperatures, velocities, and salinities.

Field Work

The first CLIMODE Flux buoy was set on November 13, 2005 from the RV Oceanus.