3D Reconstruction of Tropical Cyclone Trami (2018) eye and eyewall clouds observed by Airborne Camera

Tropical cyclones (TCs) are extreme weather phenomena that inflict damages and casualties around the globe but the capacity to measure their intensity can help mitigate the hazards that they bring. The essential parameters to estimate TC intensity from remote sensing are cloud-top height, cloud-top temperature, and cloud profiling information across the center of the storm. Thus, the TC eye is important in remote sensing as it indicates the location of the TC and its intensity. Here, we reconstructed the first ever TC eye three-dimensional model and used the model to estimate its cloud top altitude. An experiment was conducted under the SATREPS/ULAT project (SATREPS: Science and Technology Research Partnership for Sustainable Development, ULAT: Understanding Lightning and Thunderstorm) and the Tropical Cyclones-Pacific Asian Research Campaign for the Improvement of Intensity Estimations/Forecasts (T-PARCII) where images of Typhoon Trami were taken from an aircraft last September 26, 2018. Aircraft images were used to reconstruct the 3D model inside the TC eye because they provide closer views of the typhoon than that of geostationary satellite images making it easier to reconstruct a 3D model. The 3D reconstruction generated covers approximately 50 km distance from the typhoon eye at 24.3 m/pixel spatial resolution. Three cross-sections of the 3D model were analyzed, and the resulting altitude distribution was compared with the cloud-top altitude estimated by mapping the brightness temperature of the Himawari Thermal Infrared Band 13 with cloud-top height as measured by NOAA sonde data. From the 3D model, the altitude distribution ranges from 5.3 km to 14.3 km while the altitude estimated from the brightness temperature ranges from 5.2 km to 14.6 km. However, regions of altitude difference can also be observed between the two methods. This study shows that a three-dimensional model could be a good mode of typhoon visualization as it shows a more detailed typhoon structure such as the stairstep structures that was detected at some regions within the typhoon eye. This research was supported by SATREPS, funded by Japan Science and Technology Agency (JST) / Japan International Cooperation Agency (JICA).