Diana Hansen / Earth & Environmental Sciences / Faculty Mentor: Arne Winguth
Global surface temperature has been increasing since the 1850s. Dallas-Fort Worth temperatures increased over the 20th century, although precipitation generally shows a deficit over the same period. By the end of this century heat waves and drought, which are generally highly correlated, will occur with greater frequency, longer duration, and greater intensity due to anthropogenic-induced climate change. Maximum 2-m air temperature, precipitation, soil moisture, Bowen Ratio, and precipitation minus evaporation (P-E) anomalies and Standardized Precipitation Index (SPI) were calculated from Coupled Model Intercomparison Project Phase 6 (CMIP6) output and compared to estimate projected heat waves and drought through the end of the century. The number of 38C days per year increases by approximately five times from 1991-2020 to 2091-2100. Heat wave occurrence increases as temperature increases, while the onset and termination dates expand into May and September by the end of the century. SPI results point to a multi-decadal drought from 2015 to 2070, with drought becoming less severe after 2050, and finally terminating around 2080 due to increased precipitation. Both 0.1-meter and 1-meter soil moisture projections, as well as Bowen ratio and P-E reflect a similar trend compared to the SPI results. While heat wave occurrence increases, drought occurrence is mitigated by increased precipitation at the end of the century.
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