photo #6478186

Maria Popova (Member 62,333) was flying over the Caribbean Islands when she spotted this line of Stratocumulus clouds over the open water. This cloud formation, known as a convergence line, offers quite a lot of information to those, such as sailors and glider pilots, who know how to read the signs. It is possible that winds blowing across the water here from opposing directions were meeting at the line of cloud. If so, the colliding air masses would have been forced upward, where they met head-on. And wherever air rises, there’s a chance of clouds forming. Glider pilots like to use the lift in a convergence line to gain altitude. But they find theirs near coasts, typically forming in the interaction of sea breezes, where they have somewhere nearby to land. Sailors, on the other hand, can encounter them out at sea. Passing under the line of cloud, they’d likely experience a total shift in wind direction, with a relatively calm patch directly beneath. ‘Thinking about the difficult history of the Caribbean Islands,’ Maria remembers from her window seat, ‘as some of the most fought-over land on Earth, I saw this cloud stretching effortlessly across the blue expanse, as if to remind us how artificial human-made borders are.’