The Southwest of the U.S. becomes drier as rainy weather patterns are moving further north. A new study conducted by researchers at the National Center for Atmospheric Research (NCAR) looked at meteorological data spanning 35 years to find weather patterns becoming more or less frequent in the Southwest states.
Led by Andreas Prein, the research team determined that Southwest states may be transitioning to a drier climate. The recent drought spell is a strong indicator of meteorological and environmental changes to come.
The meteorological data used in the study spans the period between 1979 and 2014. In their search for precipitation drivers and their frequency, the researchers also looked at how high pressure systems and low pressure systems re-arranged over the course of 35 years.
The analysis revealed that the pressure systems critical for precipitation aren’t as frequent in the Southwest states. The Southwest of the U.S. becomes drier according to the results published in the open access article featuring in the Geophysical Research Letters.
The Southwest region is already a highly arid region. With droughts already damaging the states here, less frequent rainy weather patterns will translated in even longer droughts. Megadroughts of up to 30 years are a cause for stir and should sustain enhanced policy efforts.
A previous research conducted by researchers with the Cornell University used climate models to understand the megadroughts prospects in the Southwest region. According to the results of this study, the likelihood that megadroughts will occur in the Southwest in the U.S. soon enough is over 50 percent.
The findings of the study conducted by Andreas Prein support a similar outcome. As rainy weather patterns decrease in frequency, a dry spell is slowly taking over. The effects of the Southwest becoming an even drier region may wreak havoc. Dust storms and wildfires are just two of the adverse effects resulting from the lack of precipitation. Desertification looms on the horizon. Water management policies may become increasingly difficult to control.
The NCAR research team looked at three weather systems which are known to ensure precipitation in the Southwest of the U.S. These include low pressure systems in the North Pacific. Plotting meteorological data spanning 35 years, the researchers observed that low-pressure systems aren’t forming at the same frequency anymore.
Moreover, they are pushed over by high pressure systems. Other studies observed that average pressure systems are moving towards the north. As a result, drier conditions which inhibit rainy weather patterns are installed.
The Southwest of the U.S. becomes drier. However, the research makes no correlation with climate change, as this fell outside the scope of the current study.
Photo Credits: onlinelibrary.wiley.com, Andreas F. Prein et. all