Why southern states may face a DUSTIER future: New Data
Thursday, June 28, 2018, 14:31 - This century dust storms are becoming more frequent in many regions of our planet.
As greenhouse gas emissions increase, so do temperatures, leading to greater and more extensive drought conditions in some places. Climate models have been used in a NOAA research study to better understand how drought could evolve in the 21st century and what these drier scenarios could mean for the future of dust storms in the United States.
Climate models show a tendency for drought risk to increase over portions of the southwest and central U.S. in the coming decades, mainly in connection with an increase in the concentration of greenhouse gases. The regions found to have a greater probability of becoming drier happen to overlay the major dust sources in the United States. In the past, changes of dust activity in the U.S. have been mainly associated with variations in precipitation, soil bareness and surface wind speeds.
The high number of variables involved in creating a dusty environment, together with the uncertainty of dust modeling, makes it challenging to confirm how much and where dust activity will increase in the U.S. Results from this study do show that dustier periods would be more probable in the Southwest and Southern Plain states, while some areas of the Northern Plains could actually see a decrease in the number of dust events.
Specific model results show dustier summers in portions of southeast California, western Arizona and eastern New Mexico, and a significant increase extending across the southern Plains, from Kansas across Oklahoma into much of Texas. This dust-driven scenario would be mainly a result of increasing drought, enhanced land surface bareness and an increase in surface winds across the region in relation to the intensification of the Great Plains low-level jet.
Other currently dusty areas like Nevada and southern Idaho would actually experience fewer dust days, as would portions of the Great Plains from Missouri to North Dakota. Much of this decrease trend would be related to a wetter environment and reduced bareness as vegetation would appear earlier in the season.
One of the main limitations of the study, was that the modelling did not contemplate human induced changes to land surfaces in the region. Farming, grazing, urban growth, deforestation or even reforestation where left out the calculations to avoid further complexity, and an easier analysis of the results based mainly on the mentioned atmosphere-land interactions.
However, the study performed by NOAA scientists is a step forward towards understanding how and when drier environments can cause dust events in general to become more frequent in the U.S.
Dust storms can have a tremendous negative impact on both the social and economic aspects of a region. A better prediction of what the future looks like will certainly help improve risk management and resource planning.