By\u00a0Julia Griffin, Nov 14, 2018<\/p>\n
Hurricane Harvey swamped Houston with seven days of pounding rain last August. When scientists went back to look at historical weather patterns, they reported Harvey dumped 20 percent more rain than it typically would have. The culprit: climate change.<\/p>\n
Today, we know that Harvey wasn\u2019t an outlier. A new study, published Wednesday in Nature by the same lab<\/a>, reports that climate change intensified the rains of Hurricane Katrina, Hurricane Irma and Hurricane Maria by between 4 and 9 percent. The researchers predict that future warming could increase rainfall totals for the most extreme hurricanes and tropical cyclones by up to 30 percent.<\/p>\n Humans can also affect these torrential rains through how we engineer cities. A second analysis, also published today in Nature, found the urbanization of the Houston area<\/a> \u2014 namely its skyscrapers and the pervasive use of pavement and other concrete surfaces \u2014 made Harvey\u2019s rain dump and subsequent flooding worse.<\/p>\n Here\u2019s how both teams used supercomputers to analyze these superstorms and what their research means for future storms.<\/p>\n To model how a changing climate impacts tropical weather, climate scientists Christina Patricola<\/a> and Michael Wehner<\/a> of Lawrence Berkeley National Laboratory first had to model real life hurricanes.<\/p>\n \u201cIt\u2019s actually pretty challenging to be able to diagnose how climate change may be influencing tropical cyclones so far,\u201d Patricola said. \u201cThere\u2019s a lot of missing data or potentially missing data before the satellite era. Before satellites, a lot of observations were taken by ships, so you can imagine sometimes they would just miss a tropical cyclone.\u201d<\/p>\n Recreating those storms with computers can help fill in gaps in those hurricane observations. To do that, the team used supercomputers to model 15 major tropical cyclones that formed in the Atlantic, Pacific or Indian Oceans in the last threes decades. Storms included Hurricanes Andrew, Katrina and Matthew as well as Typhoon Haiyan and Tropical Cyclone Gafilo.<\/p>\n The researchers simulated each storms\u2019 formation, track and wind speeds and compared them to the real-life events.<\/p>\nWhat the scientists did<\/h2>\n