Observations to Quantify Air-Sea Fluxes and their Role in Climate Variability and Predictability

Abstract

Flux products quantifying exchanges between ocean and atmosphere are needed for forcing models, understanding ocean dynamics, investigating the ocean's role in climate, and assessing coupled models. Research experiments are essential to improve flux parameterizations, and longer research deployments are required to sample rare events. Urgently needed technological improvements include longer battery life, more robust sensors and improvement of sensors for humidity, precipitation and direct gas and particle fluxes. A range of different flux products are needed, incorporating data from ships, satellites and models in different combinations and using different methods. All products must be characterized with uncertainty estimates. Dataset validation requires high quality observations from ocean flux reference sites and from ships. The continued development of flux products from satellites provides much-needed sampling. Continual intercomparisons among products and with high quality observations will lead to improved flux datasets, while improvements to the flux data management system would facilitate these intercomparisons.

Synthesis and Assimilation Systems - Essential Adjuncts to the Global Ocean Observing System

“…With the former, the severe under-sampling of the water column and of most regions of the ocean in the early periods, the issues of biases/uncertainties in air-sea fluxes (e.g., [43], [44]) and model biases [45] take on greater importance.…”

“…The Objectively Analyzed air-sea Fluxes (OAFlux [66]) is another example of hybrid products that blend NWP, satellite and in situ variables. Reference [44] points out that these products also suffer from changes in the observing system and, possibly, changes in the operational NWP system. Hence, the problem of inhomogeneity remains in diagnostics of decadal variability and trends.…”

“…Scatterometer missions are essential for estimates of surface momentum and turbulent heat fluxes. Improvements needed for the coming decade include improved sampling at high wind speeds and under rain conditions ( [44], [67]) and resolution of the diurnal and inertial forcing. Remote sensing of latent and sensible heating remain a challenge [68] with considerable uncertainty in how to estimate near -surface air temperature and humidity remotely [69].…”

The Role of the International Comprehensive Ocean-Atmosphere Data Set in the Sustained Ocean Observing System

“…Fluxes at the ocean-atmosphere interface are critical for understanding the earth system [9]. Direct in situ measurements are possible, however these require expensive instrumentation and detailed information about the motion of the ships or other platforms, the location of the instruments and the flow distortion over the platform.…”

On polarimetric characteristics in SAR images of mesoscale cellular convection in the marine atmospheric boundary layer

“…Because these structures exhibit coherent up and down drafts, they produce coherent perturbations in the wind, temperature, and humidity fields and contribute significantly to vertical MABL fluxes of heat, momentum, and humidity. Thus, it is important to forecast and parameterize these effects and to investigate their structure and dynamics [Young et al, 2002;Fairall et al, 2009]. Synthetic aperture radar (SAR) is a powerful sensor to study the vast array of MABL phenomena via their ocean surface signatures.…”