Dear Tom,
Which ocean is warmest at its peak in the summer, the Pacific or the Atlantic?
Jona Osaka,
Chicago

Dear Jona,
The Pacific and Atlantic Oceans are, respectively, the world’s largest and second-largest oceans. The area of the Pacific Ocean, 63.8 million square miles, is about twice that of the Atlantic, at 31.8 million square miles. The waters of the Pacific Ocean comprise the world’s largest heat reservoir, by far, and it is the warmest ocean, overall, of the world’s five oceans. (The other oceans are the Arctic, Antarctic and Indian Oceans.) The Pacific Ocean has approximately four times the intense sun-heated surface area in the tropics compared with the Atlantic Ocean. This is an important consideration because heat exchanges between air and ocean profoundly influence the world’s weather.