Helped by NASA’s Goddard Institute for Space Studies, a study analyzing the relative intensity of droughts and the destruction these events caused, has discovered that although California’s 2014 summer was the driest (even relative to areas with the driest conditions) it still wasn’t on the same level as the drought of 1934. Benjamin Cook, lead researcher on the study, said, “We noticed that 1934 really stuck out as not only the worst drought but far outside the normal range of what we see in the record. Dust storms may have dried things out further and kicked 1934 into a really extreme event.”
The research, going as far back as 1000 AD, was recently accepted for publication by the journal of the American Geophysical Union as part of the journal Geophysical Research Letters.
In 1934, nearly 72% of the western United States was affected by the drought. It was long regarded by researchers as the culmination of natural and human-related events caused by dust storms. Failed plans for the crop planning caused the dust storms.
NOAA records reported that, from 1000AD to 2005, the drought was estimated to be seven times bigger than all other droughts operating on the same intensity. And it beat the record-breaking drought that last happened in 1580.
Still, researchers are finding signs that the same emergent conditions that allowed for the 1934 drought to happen are again in effect this year. High pressure in the ridges over the Pacific Coast seems to be the problem, as it deflects storms coming in from western states. Low rainfall levels worsen the drought. Cook said high-pressure systems like those found in the winter of 1933-1934 could send storms farther north than normal, effectively and disastrously shutting out the rain and storms that otherwise would have entered California.
Recreating the 1934 drought, though, has enabled researchers to analyze what factors were in play as the calamity took place, as well as whatever preexisting conditions had aggravated the drought, inducing it to reach near catastrophic levels of intensity. One question though, as to what caused high-pressure ridges to develop over the western states, remains unanswered.
Cook added that ocean temperatures could be a factor, but most of the evidence suggests just variables in weather and atmospheric conditions at work. Thus, while the past summer in California might be the worst drought the decade has ever seen, it is still a long way from drought conditions experienced in 1934. And though the same factors might be in play, Cook reassures the public that there are measures already in place to prevent the 1934 drought from happening and revisiting its devastation on California again.
(Photo courtesy of Jen)