In the wake of Tropical Cyclone Tej, which swept through the Arabian Peninsula in late October 2023, a groundbreaking study published in the journal *Frontiers in Marine Science* has unveiled the storm’s profound impact on the region’s oceanic environment. Led by Veeranjaneyulu Chinta of the Ningbo Institute of Digital Twin, Eastern Institute of Technology in China, the research offers a high-resolution vertical analysis of the cyclone’s effects, providing critical insights that could shape future energy and environmental strategies.
Tropical cyclones are known to significantly alter the upper oceanic environment through a mix of physical and biogeochemical processes. Cyclone Tej, a category 3 storm, was no exception. The study, which utilized satellite remote sensing and model-based ocean reanalysis products, revealed that the cyclone induced a notable cooling of sea surface temperatures (SST) by 2.5°C to 4.0°C. This cooling was particularly pronounced within cyclonic eddies and along the right side of the storm track. “The cooling effects penetrated the upper 100 meters of the ocean due to wind-induced vertical mixing and Ekman upwelling,” explained Chinta. This mixing process, driven by the storm’s powerful winds, brought cooler, nutrient-rich waters to the surface, fostering a significant increase in chlorophyll-a (Chl-a) concentrations—up to 6 mg/m3, a fourfold rise.
The enhanced subsurface Chl-a levels were observed down to 50 meters, indicating a robust phytoplankton bloom. This bloom is a direct result of nutrient entrainment, a process where nutrients from deeper waters are brought to the surface, stimulating phytoplankton growth. “The increased chlorophyll-a concentrations reflect the nutrient redistribution driven by the cyclone’s passage,” Chinta noted. This phenomenon has significant implications for the marine ecosystem and, by extension, the energy sector, particularly for industries reliant on marine resources.
The study also highlighted contrasting vertical motions in the ocean. Sea surface height (SSH) dropped below 0.05 meters in cyclonic eddies located around 12°N, 56°E, while it rose above 0.8 meters in anticyclonic eddies near 15°N, 55°E. These contrasting motions influence the distribution of nutrients and carbon dioxide (CO2) in the upper ocean. Surface pH levels declined by 0.05-0.1 units, and dissolved inorganic carbon (DIC) concentrations increased to 2.1-2.2 mol/m3 in the upper 100 meters. This increase is attributed to enhanced CO2 uptake and the upwelling of CO2-rich waters.
The research underscores the intricate interplay between physical and biogeochemical processes in the ocean. Cyclonic eddies were found to be associated with lower SSH, higher Chl-a, and elevated DIC levels. “This study provides the first high-resolution vertical analysis of post-Tej biogeochemical responses in the Arabian Peninsula,” Chinta stated. “It highlights eddy-modulated nutrient redistribution as a key driver of phytoplankton bloom.”
The findings have far-reaching implications for the energy sector. Understanding the coupled physical-biogeochemical impacts of tropical cyclones can inform strategies for sustainable marine resource management and carbon sequestration. As the Arabian Peninsula continues to face the challenges of climate change, this research offers valuable insights into the region’s oceanic dynamics, paving the way for more informed decision-making in energy and environmental policies.
Published in the journal *Frontiers in Marine Science*, this study not only advances our scientific understanding but also underscores the need for integrated approaches to managing the impacts of tropical cyclones on the oceanic environment. As Chinta and his team continue to explore these complex interactions, their work will undoubtedly shape future developments in the field, offering hope for a more resilient and sustainable future.