Project Objectives

The primary objectives of the  MAXSS project is

to provide guidance and innovative methodologies to maximise the synergetic use of available Earth Observation data (satellite, in situ) to improve understanding about the multi-scale dynamical characteristics of extreme air-sea interaction.

Other objectives are

  • to organise, dynamically combine and optimally use all available data and numerical models,
  • to support advanced studies, reveal key non-trivial interactions,
  • to break the Rapid Intensification (RI) logjam,
  • to emulate possibly more accurately complex processes to speed-up numerical ensemble-simulations and
  • to improve both real-time predictions.

A reference homogenised data record will be essential

  • to build functional relationships between collected observations,
  • to springboard the development of data-model-driven techniques dedicated to unveil essential precursors, as well as
  • to quantify the uncertainty over medium to long range forecasts and
  • to quantify impacts on ocean physics, vertical fluxes and biogeochemistry, and
  • to link to major Earth system cycles (water, CO2, upper ocean ventilation and oxygen, nitrogen fixation, ...).

To date, sampling global space-time surface winds can only build on medium- and low resolution estimates, and the integration of these different multi-modal measurements into a single new combined wind product is a key challenge of the project.  The central objective is to emphasize the combined complementarities of low resolution (SMOS, SMAP, AMRS-2, CYGNSS) observations with operational scatterometer (e.g. ASCAT) all-weather 2D estimates of wind vector amplitude at about 20 km spatial resolution.

Importantly, SAR will not be used as input data of the Multi=mission  wind product but as reference to compare and homogenize all these different measurements. For instance, SAR high resolution as well as scatterometers at high resolution (on spatial grids down to 5.6 km (Vogelzang and Stoffelen, 2017) should allow us to assess the resolution impact when describing a small size vortex.

Collocated SAR (RADARSAT1/2,RCM,S1A/B) and medium-resolution microwave (passive/active) instrument data will thus be used to develop guidance for the operational use of the latter. The SAR data will be decomposed (i.e. wavenumber-polar analysis) and then averaged at the spatial resolution of each instrument to first assess the resolution impact and then the differing sensitivities of the medium-resolution observations.

Note. the local time at descending node of the SAR missions used in this project are 6pm and therefore, collocated data are expected to be available (in the Tropics) mostly for some of the passive sensors (e.g., SMOS, SMAP). The collocation will be effective for some scatterometers, such as HY-2B, HY2-C (regressing orbit), HY-2Dc, CFOSAT and WindRad, but not for others (e.g. ASCAT-A/B/C, ScatSat or OceanSat-3).