Previous studies have shown that human activities have been changing the climate, leading to increased societal vulnerability to extreme weather events due to weather variability (Intergovernmental Panel on Climate Change, AR5). In New York State, the annual average temperature statewide has risen about 2.4°F since 1970 and average annual precipitation has increased across New York State since 1900 (Horton et al. ANYAS, 2015). This emphasizes that the study of climate variability is very important. Since the variability of weather is changing over time, we want to determine if the weather is getting weirder today. Various statistical analyses on weather data can best evaluate the behavior of trends, frequency, intensity and variability of weather.
Figure 4b Figure 4c Figure 4d.
This research study examines the daily temperature record of the greater New York City region during the 1979-2014 period. Daily station observations from three greater New York City airports: John F. Kennedy (JFK), LaGuardia (LGA) and Newark (EWR), are used in this study. By applying statistic background, threshold which is formed by two standard deviation away from the mean (Normal Distribution with 95 percentile). Any data above this threshold will classify as extreme events. The extreme threshold indicates how the strength of the overall maximum is changing. μ ± 2σ where (μ: mean, σ: standard deviation)
Result: All hot extreme events occur in the summer, as expected since the extreme threshold would have a high value that would only occur during summer, the hottest season [Fig. 4a]. The annual frequency of extreme hot temperatures shows an increasing peak over a long-timescale [Fig. 4b-4d]. This agrees with the recent New York Times article related to Jim Hansen’s research. In the other words, frequency of extreme temperature tends to continue increase due to climate change.
