This is supposed to be the bottom of Mendocino Lake—seriously.
A new study
released by NASA says that California is 20 inches of precipitation short of where it should be. It's another stark reminder of how serious the drought in California is. The study's lead author is Andrey Savtchenko at NASA's Goddard Space Flight Center in Greenbelt, Maryland.
The state as a whole can expect an average of about 20 inches of precipitation each year, with regional differences. But, the total amount can vary as much as 30 percent from year to year, according to the study.
In non-drought periods, wet years often alternate with dry years to balance out in the short term. However, from 2012 to 2014, California accumulated a deficit of almost 13 inches, and the 2014-2015 wet season increased the debt another seven inches, for a total 20 inches accumulated deficit during the course of three dry years.
[bold my emphasis]
The study was done using 17 years of satellite data and over three decades of observations and model data collected since 1979 in California. So where is the water?
The majority of that precipitation loss is attributed to a high-pressure system in the atmosphere over the eastern Pacific Ocean that has interfered with the formation of atmospheric rivers since 2011.
Atmospheric rivers occur all over the world. They are narrow, concentrated tendrils of water vapor that travel through the atmosphere similar to, and sometimes with, the winds of a jet stream. Like a jet stream, they typically travel from west to east. The ones destined for California originate over the tropical Pacific, where warm ocean water evaporates a lot of moisture into the air. The moisture-rich atmospheric rivers, informally known as the Pineapple Express, then break northward toward North America.
This is an example of an "atmospheric river" from December of last year.
Before we all jump out of a collective window, this research doesn't necessarily mean that the sky is falling—yet. California has a long history of very dry and very wet periods and what has made this particular drought so newsworthy, amongst other things, is that California has grown so much over the last few decades.
"Drought has happened here before. It will happen again, and some research groups have presented evidence it will happen more frequently as the planet warms," Savtchenko said. "But, even if the climate doesn’t change, are our demands for fresh water sustainable?"
The current drought has been notably severe because, since the late 1980s, California's population, industry and agriculture have experienced tremendous growth, with a correlating growth in their demand for water. Human consumption has depleted California's reservoirs and groundwater reserves, as shown by data from NASA's Gravity Recovery and Climate Experiment (GRACE) mission, leading to mandatory water rationing.
The study also tackles speculations on El Niño's possible effect on California's water has been and might be. Many are hoping that El Niño can bring some relief to the parched state; but be careful what you wish for the researchers say:
"If this El Niño holds through winter, California’s chances to recoup some of the precipitation increase. Unfortunately, so do the chances of floods and landslides," Savtchenko said. “Most likely the effects would be felt in late 2015-2016.”