"Wū gān" is used as a phonetic annotation in "Zhengzitong" (正字通), pronounced "àn". Shen Quanqi, in his poem "Night Berth in Yuezhou" (夜泊越州诗), wrote: "Wū gān yíng hǎi ruò, pī lì gěng tiān wú." The annotation states: "Wū gān" refers to a hurricane. "Tiān wú" is the name of the sun god of Chaoyang Valley, also known as the Water Master. For detailed information, please refer to "Classic of Mountains and Seas" (Shanhaijing).