File:Dust storm over the Sea of Japan (MODIS 2015-04-22).jpg

English: A thick cloud of dark tan sand and dust blew over the Sea of Japan in mid-April, 2015. The Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA�s Aqua satellite captured this true-color image on April 17 at 04:45 UTC (12:45 a.m. EDT).

The dense sand and dust was likely from the severe dust storm that blanketed Beijing, China on April 15-16. According to the South China Morning Post, that storm was considered to be the strongest sandstorm to hit Beijing in 13 years. The storm also affected parts of Xinjiang, Inner Mongolia, Ningxia, Tianjin, Gansu, Shaanxi, Shanxi, Hebei and Jilin.

The South China Morning Post also reported that many areas in the capital recorded PM10 air pollution readings of nearly 1,000 micrograms per cubic meter, a level considered hazardous. The US embassy�s readings of PM2.5 particulates � considered most dangerous to human health � exceeded 300, also considered hazardous. Residents of the city were warned to stay indoors, and those who did venture out wore masks over their nose and mouths to protect against the fine sand.