During a tropical year the sun moves from Vernal Equinox to Vernal Equinox.

在一个回归年内，太阳从春分点转回到春分点。

youdao

This paper advocates that the six states of the dragon described in the hexagram of Qian are six celestial phenomena of the star of the green dragon in a tropical year.

本文认为乾卦六爻爻辞所说的“六龙”各种状态是苍龙星在一个回归年中所运动的不同天象。

youdao

Cuba has a tropical climate with year-round sunshine.

古巴属于热带气候，终年阳光明媚。

《柯林斯英汉双解大词典》

They say thirty million tropical fish are disappearing every year because of a growing interest in tropical fish.

VOA: special.2010.08.10

Statistics from Australia's National Tidal Center show sea levels have increased by 8.6 millimeters a year off Perth and by 8.1 off the tropical Kimberley region over the past two decades.

VOA: standard.2009.11.09

I'm going to do a master's program in London for a year in tropical medicine and international health.

NPR: Doctor Describes Scene in Darfur

That combination keeps the local area at a consistent tropical green year-round.

FORBES: America's Wildest Weather Cities

His brother, Roger, visits the beach once a year, like a tropical storm that changes everything.

NEWYORKER: Brother on Sunday