Global climate change
Morning low cloud cover is becoming less common along the Southern California coast
By Brett Anderson, AccuWeather senior meteorologist
6/06/2018, 11:44:15 AM
Share this article:
A combination of a warming climate climate and increased urbanization (heat island effect) has caused a 25 to 50 percent decrease in low cloud cover in the greater Los Angeles area since the 1970s, according to a new peer-reviewed study led by Columbia University's Lamont-Doherty Earth Observatory.
Low, marine-layer clouds along the southern California Coast from satellite.
The cloud decrease is driven mainly by urban sprawl, which increases near-surface temperatures, but that overall warming climate is contributing, too. Increasing heat drives away clouds, which admits more sunlight, which heats the ground further, leading to drier vegetation and higher fire risk, said lead author of the study and bioclimatologist Park Williams.
Low stratus clouds typically form over coastal Southern California during the early morning. As temperatures rise during the day, the clouds typically dissipate later in the morning and into the early afternoon.
These low cloud bases have risen an average of 150 to 300 feet since the 1970s. The higher bases have allowed the clouds to burn off an average of two hours earlier than what they did 40 or so years ago.
The research team compared hourly cloud observations at many California airports since the 1970s and compared that information with the U.S. Wildland Fire Assessment System data base. The team determined that periods of less cloud cover during the summer correlated neatly with lower vegetation, moisture and thus more danger of fire, according to the report
However, the team did not find an increased trend in total area burned in the summer due to decreasing cloud cover. The likely reason for this is that newer technology better firefighting techniques in recent years have been able to better contain fires compared to the earlier years.
This study was recently published in the Geophysical Research Letters.
The views expressed are those of the author and not necessarily those of AccuWeather, Inc. or AccuWeather.com
Comments that don't add to the conversation may be automatically or manually removed by Facebook or AccuWeather. Profanity, personal attacks, and spam will not be tolerated.
Global climate change
Global climate change - November 28, 2018, 11:11:32 AM EST
Extreme heat events in the U.S. and Canada have increased since 1980.
Global climate change - November 20, 2018, 1:03:09 PM EST
Another top five warmest October on record for the globe.
Global climate change - November 18, 2018, 7:27:14 AM EST
Combating climate change in the U.S. through natural solutions.
Global climate change - November 09, 2018, 12:04:58 PM EST
Ragweed expected to expand further into the Northeast U.S. as the climate warms this century.
Global climate change - November 02, 2018, 1:43:59 PM EDT
New research has determined that the Earth is even more sensitive to fossil-fuel emissions than previously thought.
Global climate change - October 18, 2018, 10:31:26 AM EDT
Climate change may make beer more of a luxury item in the future.
Key takeaways from the latest IPCC report on the impacts of a 1.5 degree Celsius rise in global temperature
Global climate change - October 11, 2018, 9:44:57 AM EDT
The goal of limiting future warming to 1.5 degree Celsius above pre-industrial levels.