"The Tropical Upper Atmosphere 'Fingerprint' of Global Warming"
"In the tropics at heights more than 10 miles above the surface, the prevailing winds alternate between strong easterlies and strong westerlies roughly every other year. This slow heartbeat in the tropical upper atmosphere, referred to as the quasibiennial oscillation (QBO), impacts the winds and chemical composition of the global atmosphere and even the climate at Earth's surface."