Measuring Winds and Clouds Inside Tropical Cyclones with the Proposed ESA Earth Explorer 11 WIVERN (Wind Velocity Radar Nephoscope) Mission

WIVERN, a space mission proposed within the ESA Earth Explorer program, aims to provide new insight in the cloud and dynamical structure of tropical cyclones (TC). The mission hinges upon a 800 km swath conically scanning 3-mm Doppler radar. Through notional simulations of WIVERN observations based on the ClouSat nadir looking 3-mm radar, our study demonstrates that WIVERN could profile most of the TCs, particularly the glaciated part of the cloud above the freezing level and the precipitating stratiform regions. Because of its lower sensitivity, the WIVERN radar would provide 75% observations of clouds and 45% accurate horizontal winds in TCs in comparison to where CloudSat detects clouds. However, thanks to its rapid conical scanning, WIVERN would indeed provide ∼50 times more observations of clouds and 30 times more observations of horizontal winds in comparison to the number of clouds sampled by CloudSat.The proposed observing system has the potential to complement the sparse observations from aircraft-reconnaissance measurements and by ground-based and airborne Doppler radars, thus providing additional constraints into numerical weather prediction models and hopefully further improving forecasts of tropical cyclone intensity and track.