Simple past tense and past participle of upwell.(verb)
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Use "upwelled" in a sentence
"As if Paul's words had been a spell of magic, discouragement and weariness passed from her spirit, and hope upwelled in her heart like a dancing fountain."
"Other continental shelf regions may also be impacted where anthropogenic CO2-enriched water is being upwelled onto the shelf."
"As the ocean's deeper waters contain more nitrogen and phosphorous, more marine life lives in the upwelled water."