MUSCAT, Oman — A modeling study involving researchers from Sultan Qaboos University has found that sea surface temperature and Oman’s terrain influenced simulated Tropical Cyclone Shaheen through different mechanisms, affecting its intensity, track and rainfall distribution.
The researchers used Tropical Cyclone Shaheen, which directly affected northern Oman in October 2021, as a case study to examine how changes in environmental and surface conditions influence regional weather-model simulations.
Using a regional ensemble of the ICON numerical weather prediction model at a spatial resolution of 6.5 kilometers, the team conducted controlled sensitivity experiments in which sea surface temperature, terrain height and sea-surface roughness were modified. They then assessed the effects on the simulated cyclone’s intensity, path, rainfall patterns and atmospheric structure.
Among the tested changes, increasing sea surface temperature by 2°C produced the strongest response in the model. The warmer sea surface intensified the simulated cyclone and increased rainfall along coastal areas.
Changes to the terrain produced a different response. Reducing terrain height primarily shifted the simulated cyclone’s track and weakened terrain-enhanced rainfall over mountainous areas. The terrain changes also reorganized the cyclone’s vertical circulation, affecting low-level flow, moisture-flux convergence, mid-level ascent and upper-level divergence.
By comparison, physically based changes to sea-surface roughness had a smaller effect on the simulated cyclone’s intensity and precipitation structure.
The findings indicate that sea surface temperature mainly influenced storm intensity and the magnitude of coastal rainfall, whereas terrain height had a greater effect on the cyclone’s path, vertical circulation and the geographical distribution of rainfall.
The study provides new insights into how numerical weather prediction models respond to important surface and environmental conditions during tropical cyclones affecting Oman and the surrounding region. The findings may support further evaluation and improvement of regional cyclone simulations and assessments of heavy-rainfall and flood hazards.
The researchers emphasize that the findings are based on controlled sensitivity experiments involving one cyclone. The 2°C increase was used to test the model’s response and should not be interpreted as a direct prediction of how future cyclones will behave.
The study was conducted by Badriya Al Mawali, Issam Ali and Alaa Ibrahim from the Physics Department at Sultan Qaboos University. Badriya Al Mawali is also affiliated with Oman’s Directorate General of Meteorology. Martin Köhler and Maike Ahlgrimm are affiliated with Deutscher Wetterdienst (DWD), and Sultan Al Yahyai is affiliated with Code Academy in Muscat, Oman.
The article, “Sensitivity of ICON ensemble simulations of tropical cyclone Shaheen to sea surface temperature and terrain-height changes,” was published in Scientific Reports .
Scientific Reports
Computational simulation/modeling
Not applicable
Sensitivity of ICON ensemble simulations of tropical cyclone Shaheen to sea surface temperature and terrain-height changes
3-Sep-2026