In the wake of tropical cyclone Tej, which swept through the Arabian Peninsula in late October 2023, a team of researchers led by Veeranjaneyulu Chinta from the Ningbo Institute of Digital Twin, Eastern Institute of Technology in China, has uncovered significant insights into the storm’s impact on the region’s oceanic environment. Published in the journal *Frontiers in Marine Science* (translated as “前沿海洋科学”), the study sheds light on the complex interplay between tropical cyclones and marine ecosystems, with potential implications for the energy sector.
Tropical cyclones are known to stir up the ocean, both physically and biochemically. Cyclone Tej, a category 3 storm, was no exception. The research team utilized satellite remote sensing and ocean reanalysis models to track the storm’s immediate effects on the upper ocean. They found that the cyclone induced a substantial cooling of sea surface temperatures (SST) by 2.5°C to 4.0°C, particularly within cyclonic eddies and along the right side of the storm’s path. This cooling extended down to depths of 40-50 meters, driven by wind-induced vertical mixing and Ekman upwelling.
One of the most striking findings was the significant increase in chlorophyll-a (Chl-a) concentrations, a marker of phytoplankton biomass. “We observed a fourfold rise in Chl-a, reaching up to 6 mg/m3,” said Chinta. This surge in phytoplankton activity is attributed to the entrainment of nutrients from deeper waters, a process that can have cascading effects on the marine food web.
The study also revealed contrasting vertical motions in the ocean. Sea surface height (SSH) dropped below 0.05 meters in cyclonic eddies and rose above 0.8 meters in anticyclonic eddies, indicating complex patterns of water movement. Additionally, the storm led to a decline in surface pH and an increase in dissolved inorganic carbon (DIC) concentrations in the upper 100 meters of the ocean. These changes are linked to enhanced CO2 uptake and the upwelling of CO2-rich waters, highlighting the intricate balance between physical and biogeochemical processes.
For the energy sector, these findings are particularly relevant. The Arabian Peninsula is a hub for offshore oil and gas operations, and understanding how tropical cyclones alter oceanic conditions can help mitigate risks and optimize resource management. “The redistribution of nutrients and the resulting phytoplankton blooms can influence marine ecosystems and, consequently, the operations of offshore energy facilities,” Chinta explained.
Moreover, the study’s high-resolution vertical analysis provides a detailed look at the post-cyclone biogeochemical responses in the region. This knowledge can inform future research and policy decisions, ensuring that the energy sector is better prepared for the impacts of tropical cyclones.
As climate change continues to intensify tropical cyclone activity, the insights from this study become increasingly valuable. By understanding the coupled physical-biogeochemical impacts of these storms, we can better predict and manage their effects on marine environments and the industries that depend on them. The research conducted by Chinta and his team marks a significant step forward in this endeavor, offering a comprehensive analysis that could shape future developments in the field.