Tropical Cyclone–Radiation Interaction in NASA Reanalysis and Model Products as Compared to CloudSat Observations

Abstract Tropical cyclone (TC)–radiation interaction is important in TC development in which the structure of moisture and cloud modulates radiation. This study validates the representation of moisture, cloud, and TC–radiation interaction in the products of the Goddard Earth Observing System Model, version 5.12.4 (GEOS-5.12.4), by utilizing a satellite-based observational estimation of TC–radiation interaction from the CloudSat TC (CSTC) dataset. The GEOS-5 products include the Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2), and the MERRA-2 Atmospheric Model Intercomparison Project (AMIP) set of simulations (M2AMIP). Under similar TC intensity, GEOS-5 TCs experience a comparable longwave (LW)-cloud feedback to that in CSTC despite having at least an order of magnitude less cloud ice mass. This results from the presence of upper-tropospheric ice clouds which are efficient at reducing the outgoing LW radiation. The clear-sky LW feedback is greater in GEOS-5 TCs which results from a greater occurrence frequency of dry conditions in the TC’s outer region. The LW radiatively driven circulation favors TC development, while the shortwave (SW)-driven circulation is confined to the upper troposphere and modulates the circulation at the outflow layer. TCs in CSTC experience a deep-layer LW radiatively driven circulation, while that in GEOS-5 TCs is confined to the upper troposphere and is less effective at supporting TC development, which might contribute to the low-intensity bias of GEOS-5 TCs. The top-heavy distribution of ice in GEOS-5 TC restricts the radiatively driven circulation to the upper troposphere. The small discrepancies between GEOS-5 outputs indicate that the data assimilation process for MERRA-2 does not substantially alter the TC–radiation interaction in GEOS-5. Significance Statement Tropical cyclone (TC)–radiation interaction has been regarded as one of the important factors for TC development in recent years. The spatial structure of moisture and cloud greatly affects TC–radiation interaction. This study aims to validate the TC–radiation interaction in climate model outputs by using observational evaluation from satellite products. Discrepancies in cloud and moisture properties are shown between climate model outputs and satellite products. These discrepancies lead to the variation in the ability of radiation to increase the energy in the TC core and drive the transverse circulation that affects TC development. These results provide a foundation for understanding the importance of cloud–radiation and moisture–radiation interactions in TC development and support a quantitative validation for numerical modeling.