Abstract Small‐scale gravity waves (GWs) generated by Hurricane Sam (2021), Fiona (2022), and Dora (2023) are studied using COSMIC‐2 GNSS‐radio occultation (RO) temperature retrievals and ERA5 reanalysis data set, from which we categorize three GW types that are commonly observed in the hurricanes studied. Using Least Squares Wavelet Analysis, our results show that these GW characteristics align well with the conceptual GW theories. Based on GW properties, we introduce a new convention to name these three GW bands as Type A ( 12 km) generated by thermal forcing, dominant in the troposphere; Type B ( 3–10 km) that is usually shifted toward shorter wavelength by wind filtering effects, including the small‐scale waves ( 2–3 km) induced by overshooting convection; and Type C ( 3–10 km) produced by a combination of thermal forcing and the obstacle effect, prevailing in the stratosphere. GWs observed in Sam and Fiona reveal the spiral propagation and the concentric structure that agree with previous investigations, while displaying an asymmetric east‐west wave field in the lower stratosphere. We ascribe this asymmetry as a joint result of wind filtering and obstacle effects. Although the GWs from Dora lack a consistent pattern at different altitudes likely due to a GW interference in the upper troposphere‐lower stratosphere region, distinct GW bands remain evident in the spectral results. Considering the GW similarities among the three hurricanes studied, we reckon the observed GW patterns might be present in other hurricanes, although a hurricane might not reveal all the suggested GW types.
Wang et al. (Sun,) studied this question.