Drought continues to grip over half of the land in the United States. In Arizona over 92% is experiencing drought conditions. However, the conditions are slightly improved over the drought measurements from this time last year.
NASA Earth Observatory recently released the below images to show where the amount of water stored in the ground has improved with the drop in drought severity. Unfortunately, Arizona remains dry compared to the average measurements.
Portions of the article are from NASA Earth Observatory.
The maps combine data from the Gravity Recovery and Climate Experiment (GRACE) with other satellite and ground-based measurements.
NASA Earth Observatory says "They represent changes in water storage related to weather, climate, and seasonal patterns."
The first map shows how much moisture is in the "root zone", which is three feet of soil.
The second map shows water storage in shallow aquifers.
Aquifers are natural, underground storage spaces where water gathers.
Water can sit in the aquifers for days to decades to tens of thousands of years.
NASA Earth Observatory says "The current water content in both maps is compared to a long-term average for early June between 1948 and 2009. The darkest red regions represent dry conditions that should occur only 2 percent of the time (about once every 50 years). To see the monthly changes from August 2002 through May 2013, download the animation below the second image."
Below NASA Earth Observatory breaks down what the colors on the map mean for the moisture content.
"The root zone map offers perspective on the short-term (weeks to months) water situation; for instance, the passage of a tropical storm can have a distinct impact on root zone moisture. Compared to the summer of 2012, moisture near the surface in June 2013 is significantly better in most of the eastern and northern portions of the continental United States, particularly the Midwestern areas around the Mississippi River. Flooding has instead become the problem in Montana and North Dakota. Portions of Arizona, Nevada, and southeastern California are extremely dry, even by desert standards.
The second map tells more of a long-range story. Groundwater takes months to seep down and recharge aquifers, and that clearly has not happened in the Rocky Mountain states and most of Texas. Underground storage has improved in much of the southeastern and central U.S., though not in Florida. Southern California has a deficit despite promising signs in the winter and spring. Click here to see what water storage looked like as of January 2013."