Scatterometers are instruments on aircraft or satellites that are used to measure wind speed and direction at the ocean surface. In this follow-up to a 2016 study, the surface wind in tropical cyclones around the world are studied using a large set of measurements from 2000 to 2011. The impact of tropical cyclone intensity, motion, and shear (the difference in wind between low and high levels in the atmosphere around the tropical cyclone) on the shape of the surface wind field is studied.
1. The shapes of the surface wind fields for all storms outside the RMW are changed by wind shear.
2. The shapes of the surface wind fields in hurricanes, especially the strong ones, are less impacted by shear near the RMW.
3. When the wind shear is in the same direction as the storm motion, the impact of shear is greatest. When the wind shear is in the opposite direction as the storm motion, the impact of the shear is least.
4. There is a well-known asymmetry in the rainfall in tropical cyclones due to shear. This new work shows that the most flow of air into the tropical cyclone near the surface is where rainfall is also greatest. This wind is usually fastest where the rainfall occurs, leading to larger surface- wind asymmetries than would otherwise occur.
You can find the entire paper at http://journals.ametsoc.org/doi/abs/10.1175/MWR-D-17-0019.1.