EGU25-14328, updated on 15 Mar 2025
https://doi.org/10.5194/egusphere-egu25-14328
EGU General Assembly 2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
Inhomogeneous Sea‐Salt Aerosols—A New StrengtheningMechanism for the Western North Pacific Subtropical High
Shoujuan Shu
Shoujuan Shu

The western North Pacific Subtropical High (WNPSH) significantly influences East Asian weather. In the Northwest Pacific where sea‐salt aerosols (SSAs) are abundant and the large‐scale environment is dominated by the dry subsidence of the WNPSH during summer, inhomogeneous SSAs form as a product of the environment. However, the extent to which inhomogeneous SSAs affect the WNPSH remains unclear. This study investigates the radiative effects of SSAs through numerical simulations, revealing a novel mechanism for the strengthening of the WNPSH. The results demonstrate that inhomogeneous SSAs enhance the WNPSH by generating diabatic cooling in the upper troposphere and associated unstable subsidence motion. Further considering the radiative hysteresis effects of inhomogeneous SSAs, the WNPSH further strengthens under the combined dynamic and thermodynamic influences associated with upper‐level radiative cooling. Inhomogeneous SSAs not only enhance the WNPSH but also influence the location where the central area of high pressure intensifies.

How to cite: Shu, S.: Inhomogeneous Sea‐Salt Aerosols—A New StrengtheningMechanism for the Western North Pacific Subtropical High, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14328, https://doi.org/10.5194/egusphere-egu25-14328, 2025.