noun
warm water mass; body of warm water
Technical term in oceanography referring to a distinct volume of warm water in the ocean.
暖水塊が沿岸に接近すると、海水温が上昇する。
When a warm water mass approaches the coast, the sea temperature rises.
Compound of 暖 (だん, 'warm'), 水 (すい, 'water'), and 塊 (かい, 'mass, lump').