December 19-21, 2020
When winter moisture pours in from the Pacific Ocean and creates snow within the Sierra Nevada, white blankets can even seem all through the Central Valley. Often called Tule (to Lee), this opaque mist unfold throughout California in time for the 2020 winter solstice. Though it could actually look fairly from above, the thick fog might be harmful for individuals on the bottom.
With extra rain and lighter winds in winter, humid coastal air lots transferring by way of the lowlands, and cooler air sliding down from the mountains, the San Joaquin and Sacramento valleys are fertile areas for fog formation. The daytime daylight warms the soil and results in evaporation, whereas the nighttime cooling could cause this moisture to saturate the air. When the wind is calm, the water droplets gather till clouds of fog type close to the bottom.
Tule fog tends to type after sundown and turns into thickest simply earlier than dawn. It slowly thins because the air warms up within the daytime daylight. The identify is derived from its formation over reed wetland vegetation –Los Tules or Tullin.
The Nationwide Climate Service (NWS) in Hanford, California issued indications of thick fog for a number of consecutive days in mid-December 2020. Drivers have been suggested to cut back pace and use low beam as visibility dropped to close zero in locations. “It is regular for fog to return on this time by way of to the yr, but it surely was superb how briskly and thick it got here in,” mentioned NWS meteorologist Jim Anderson The Fresno bee. Even the Hanford group tweeted a photo of conditions proper in entrance of her workplace. The sample is predicted to sporadically proceed into the subsequent week.
The above photos in pure colours have been taken between December 19-21, 2020 with MODIS (Average Decision Imaging Spectroradiometer) devices NASATerra and Aqua satellites. By midday, the Tule Fog unfold over a whole lot of kilometers in central California. This was the time for the every day switch of NASA satellites.
Regardless of the hazards, the fog is necessary to California’s crops as fruit and nut timber want satisfactory relaxation between rising seasons to be best. They get this relaxation in winter, when cooler temperatures trigger a relaxation part. Fog sometimes signifies such cooler climate; It additionally protects timber from direct daylight, which might in any other case heat the plant buds.
In line with scientists, Tule nebulae have shaped much less ceaselessly in California over the previous few many years. College of California-Berkeley researchers who used satellite tv for pc imagery discovered that the variety of foggy days decreased by 46 p.c between November and February from 1981 to 2014. Fewer foggy days correspond to fewer chilly days, and different research have confirmed that there at the moment are timber within the valley a whole lot much less chilly hours per yr.
NASA Earth Observatory photos by Joshua Stevens utilizing MODIS knowledge from NASA EOSDIS / LANCE and GIBS / Worldview. Michael Carlowicz’s story with Holli Riebeek.
