Temperature Variable Trends for High Elevations of the Southern Appalachians 1951-2015

Low-elevation sites placed less than 1000 meters above sea level overwhelmingly represent surface observations throughout the southern Appalachian region. Given that high-elevation environments often possess similar climates and ecosystems to high-latitude environments, it is hypothesized that such high-elevation sites may have experienced different trends when compared to the overall cooling trend documented for the region. Monthly observation summaries from the Global Historical Climatology Network spanning 1951-2015 all ready indicate that statistically significant warming trends are indeed present for minimum temperature, maximum temperature, mean temperature, extreme minimum temperature, and extreme maximum temperature for stations located at elevations exceeding 1000 meters above sea level. In this new study additional temperature-derived variables are considered: cooling degree days, heating degree days, the number of days in a month where minimum temperature ≤ 0 °F, the number of days in a month where minimum temperature ≤ 32 °F, the number of days in a month where maximum temperature ≥ 90 °F, and number of days in a month where maximum temperature ≤ 32 °F. Statistically significant trends were more common in the 1000-1499 meters above sea level range compared to the ≥ 1500-meter category. Results generally show that cooling degree days and the number of warm days increased, while heating degree days and the number of cold days decreased over the 65-year study period.