Deadly heat waves in the Middle East are not caused by incoming hot air, but by the atmosphere simply refusing to mix.
Extreme humid heat buildup happens when the lowest layer of the atmosphere becomes throttled and trapped against the ground. Most meteorologists assumed these events required a massive push of heat or moisture from neighboring regions. This study proves that local stabilization of the air layer is the primary driver of these lethal spikes. When the air stops mixing, moisture from the sea and heat from the sun pile up in a narrow band where people live. This finding means that local land use and urban design are more critical for survival than previously realized.
Local Mixing Governs the Buildup of Humid Heat Events in the World's Leading Hotspot
research_square · rs-9408455
Abstract Humid heat extremes pose significant risks to public health, yet beyond a few recognized favorable environmental conditions, the underlying energy buildup processes prior to the event remain elusive. The world's leading humid-heat hotspot in the Middle East exhibits extreme levels of near-surface wet-bulb temperature, moist enthalpy, and atmospheric conditional instability so severe as to challenge common physical paradigms. Here we show that the multi-day buildup of those extremes occu