The Arabian Sea is a large, vital region of the northern Indian Ocean, geographically bounded on the east by India, on the north by Pakistan and Iran, and on the west by the Arabian Peninsula and the Horn of Africa. It is a natural geographical feature, not a scheme or act, covering an area of approximately 3.862 million km². Its formation is linked to the geological event of the Indian subcontinent colliding with Asia, which occurred roughly 50 million years ago. Historically, the sea was known by various names, including the Sea of India by medieval Arabs and Mara Erythraeum by the Romans, but it gained its current name due to the Arabian merchants who controlled its trade routes from the 9th century onward.
The sea functions as a critical maritime trade route, connecting Europe and India since the 3rd millennium BCE. It connects to the Red Sea via the Gulf of Aden and the Strait of Bab-el-Mandeb, and to the Persian Gulf via the Gulf of Oman and the Strait of Hormuz. The mechanism that defines its climate and trade is the Indian Monsoon, where predictable seasonal winds—the southwest monsoon from May to September and the northeast monsoon from October to April—enabled ancient sailors to navigate efficiently. The Indus River is the largest river that drains into the Arabian Sea.
A significant recent change is the rapid warming of the Arabian Sea, which has been increasing significantly since 1951. This warming is linked to the intensification of tropical cyclones, which were once relatively rare but are now becoming more common, as seen with storms like Tauktae (2021). Furthermore, the sea contains one of the world's three largest oceanic Oxygen Minimum Zones (OMZ), or "dead zones," which is being exacerbated by warmer, calmer waters that reduce mixing and lead to a shift in the marine ecosystem. The sea's warming is also contributing to more extreme monsoon variability, impacting the densely populated coasts of western India.