Event and Seasonal Scale Variability of Surface Heat and Momentum Fluxes off Oregon and Washington

As part of the NSF-funded Ocean Observatories Initiative (OOI) Coastal and Global Scale Arrays, surface buoy meteorological measurements are made using the Air-Sea Interaction Meteorology (ASIMET) package. Radiative and bulk surface fluxes calculated from these measurements are provided as OOI data products. Both the measurements and the estimated fluxes are available through the OOI Data Portal as are all the metadata required to produce these fluxes (raw data, calibration coefficients, data product specifications, data product algorithms etc.). The Endurance Array surface buoy meteorological and oceanographic data (but not the fluxes) are also available through NDBC and, for the last 60 days, through the NANOOS Visualization System (NVS).

On the Endurance Array, ASIMET measurements are made at four locations over the Oregon and Washington shelf and slope. These locations lie within the northern California Current Marine Ecosystem. Here upwelling favorable wind forcing and atmospheric conditions occur in spring and summer months with forcing in other months driven by passing low pressure systems. The timing of both the spring transition to upwelling and the fall transition to storm forcing varies from year to year as does the strength of individual events within each season. Upwelling events are associated with strong net shortwave and latent heat fluxes. Storm events are associated with weak net shortwave fluxes and latent fluxes that vary in strength. Winter cloud cover mitigates the heat transfer from the ocean to the atmosphere by lowering the net longwave heat flux.

We will report on the surface meteorological data return for the first four years of Endurance Array operation and describe the observed event and seasonal scale variability for surface heat and momentum fluxes.