In 2017, the amount of wildfires in California has been much larger than in previous years. Until early December, almost 8,800 fires have burnt down about 5,400 km2, more than twice as California’s 5-year average. The large amount of wildfires are caused by a combination of dry conditions, maintained by a strong and long-lasting inland wind (Santa Ana), and more grassland and other vegetation that has grown during spring and summer as a result of a very wet preceding winter.
The 100 m image of last Friday, 7 December, shows a number of large wildfires in the hills near Ojai, about 100 km northwest of Los Angeles, as red dots. The extensive smoke and ash plumes are transported over the Santa Rosa and Santa Cruz islands and further over the Pacific Ocean by the north-easterly winds. The Los Angeles urban area is visible in the image lower right part.