Characterizing the Redistribution and Removal of Dust by a Tropical Cyclone using Tandem Active and Passive Satellite Sensors and Models

Clouds, convection, and precipitation can impact aerosol redistribution and removal in the atmosphere. Of key interest is the Saharan Air Layer (SAL) which is characterized as a relatively warmer and drier air environment with dust dominated aerosols between the surface and up to 7 km over the tropical and subtropical north Atlantic Ocean. This seasonal Saharan dust plume with a maximum in June and July can influence clouds, convection, and precipitation processes (e.g., aerosols may inhibit hurricanes or reduce precipitation efficiency). With the north Atlantic hurricane season nominally starting in June and ending in November, the SAL events are often coincident with tropical cyclone activity in this region. Interaction between the SAL and tropical convection offers an opportunity to evaluate tropical cyclone impacts on the redistribution and removal of dust (e.g., possibly up to two thirds of dust may be scavenged by tropical cyclones [Sauter et al. 2019]). This study provides an example methodology to assess the dust budget across a tropical cyclone path which may be used to address one of the most challenging science objectives of the NASA Observing-System Study for Aerosols, Clouds, Convection, and Precipitation (ACCP) [Braun et al., 2022].

Using tandem active and passive satellite sensors (e.g., CALIPSO, CloudSat, GPM, MODIS, and geostationary satellites) and model data (e.g., GEOS-IT), this effort follows a similar methodology as described by Sauter and L’Ecuyer et al. 2017 and Sauter et al. 2019. This algorithm quantifies the aerosol redistribution and removal processes in the presence of tropical cyclone Lorenzo in 2019. Algorithm and analysis software is developed on two platforms: within the NASA Multi-Mission Algorithm and Analysis Platform (MAAP) system and concurrently developed using similar applications provided by the NASA Science Managed Cloud Environment (SMCE). The effectiveness of the algorithm development and analysis process will be evaluated to inform the applicability of these systems in planning the Atmosphere Observing System (AOS) mission architecture.

References:

Braun et al. 2022: Aerosol, Cloud, Convection, and Precipitation (ACCP) Science & Applications Narrative, https://aos.gsfc.nasa.gov/docs/ACCP_Science_Narrative-(Mar2022).pdf.

Sauter, K., and T. S. L’Ecuyer (2017): Observational evidence for the vertical redistribution and scavenging of Saharan dust by tropical cyclones, Geophys. Res. Lett., 44, 6421–6430, https://doi.org/10.1002/2017GL074166.

Sauter, K., L'Ecuyer, T. S., van den Heever, S. C., Twohy, C., Heidinger, A., & Wood, N. (2019). The observed influence of tropical convection on the Saharan dust layer. Journal of Geophysical Research-Atmospheres, 124, 10,896-10,912. https://doi.org/10.1029/2019JD031365.