Ocean Currents Explain Why Northern Hemisphere Is Soggier 35
vinces99 writes "A quick glance at a world precipitation map shows that most tropical rain falls in the Northern Hemisphere. The Palmyra Atoll, at 6 degrees north, gets 175 inches of rain a year, while an equal distance on the opposite side of the equator gets only 45 inches. Scientists long believed that this was a quirk of the Earth's geometry – that the ocean basins tilting diagonally while the planet spins pushed tropical rain bands north of the equator. But a new University of Washington study shows that the pattern arises from ocean currents originating from the poles, thousands of miles away. The findings, published (paywalled) Oct. 20 in Nature Geoscience, explain a fundamental feature of the planet's climate, and show that icy waters affect seasonal rains that are crucial for growing crops in such places as Africa's Sahel region and southern India."
Re:What about elevation? (Score:5, Informative)
Isn't most of the land in the Northern Hemisphere?
Yes. But that doesn't explain why the Northern Hemisphere gets more rain even thousands of miles from any significant land mass. The Palmyra Atoll [wikipedia.org] is in the middle of the Pacific Ocean, about as far from any continent as possible. Yet it still gets significantly more rain than similar islands south of the equator.