Particles from the Sahara end up as far away as southern California according to a new finding.
The Scripps Institution of Oceanography said that water consumed in San Diego was traced back to dust and microbes from the Sahara.
The study is another reminder to what extent the world's ecosystems are interconnected.
The researchers found that the dust from the Sahara triggers snow storms in California mountains, reported the Associated Press.
Snow in the mountains melts in the spring and then flows into reservoirs.
The water is later consumed - filtered, of course - by local residents.
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The study was based mainly on atmospheric readings taken in February 2011.
Aerosols that were found in the Sierra Nevada were also found in Oman 10 years earlier, said the Associated Press.
Those aerosols originated from the Sahara desert and carried with them dust and microbes.
When they finally reached the Sierra Nevada mountains, they were mixed with other aerosols from China and Mongolia, reported U-T San Diego.
That mixture helped seed clouds and generate snow.
The findings were published in the journal Science.