Hadley循環 (sûn-khoân)是 (sī)指 (kí)1種 (chióng)大氣 (tāi-khì)循環 (atmospheric circulation),對 (ùi)赤道 (chhiah-tō)稱 (chhèng)權 (koân)的 (ê)氣流 (khì-liû)走 (chaú)到 (kaù)緯度 (hūi-tō͘)30° 彼 (hit)搭 (tah)沉落來 (tîm--lo̍h-lâi),閣 (koh)走轉去 (tńg-khì)赤道,造成 (chō-chiâⁿ)1个 (ê)循環。熱代 (Jia̍t-tāi)的大氣循環定著 (tiāⁿ-tio̍h)愛 (ài)可 (khó)太陽能 (thài-iông-lêng)。地球 (Tē-kiû)本身 (pún-sin)有 (ū)23.5° 个特崎 (te̍k-khi) (axial tilt),干焦 (kan-taⁿ)熱代附近 (hū-kīn)幾 (kúi)10度 (tō͘)的範圍 (hoān-ûi)佇 (tī)透 (thaù)中晝 (tiong-taù)的時 (sî)日頭 (Ji̍t-thaû)會 (ē)得 (tit)直接 (ti̍t-chiap)炤著 (chhiō--tio̍h),結果 (kiat-kó),太陽 (thài-iông)輻射 (hok-siā) (solar radiation) 的鍋 (e)nú-jih (energy) 攏 (lóng)集中 (chi̍p-tiong)佇赤道,遮的 (chiah-ê)熱能 (jia̍t-lêng)大份 (toā-hūn)用 (ēng)未熱 (bī-jia̍t) (潛熱 (chiâm-jia̍t),latent heat) 的形式 (hêng-sek),靠 (khò)雷攻予 (lûi-kong-hō͘) (thunderstorm) 的對流 (tùi-liû) (convection) 作用 (chok-iōng),送 (sàng)到大氣層 (tāi-khì-chân)氣 (khì)。