Updated

Each summer, microscopic dust particles kicked up by African sandstorms blow thousands of miles (kilometers) across the Atlantic to arrive in the Caribbean, limiting airplane pilots' visibility to just a few miles and contributing to the suffering of asthmatics trying to draw breath.

But the phenomenon is attracting ever more attention from regional scientists who say the clouds have grown, even if there's no global consensus on the issue.

In recent days and weeks a particularly large cloud dusted eastern Caribbean islands, made for hazy skies and intense, tangerine-tinted sunsets off Havana, drifted over Mexico's Yucatan Peninsula and was detected as far away as Wyoming.