Tracking Climate Change through the Spatiotemporal Dynamics of the Teletherms, the Statistically Hottest and Coldest Days of the Year
Fig 2
Plots establishing Teletherm date and Teletherm Periods for the examples of A: the hottest summer Teletherm (Death Valley, California) and B: the coldest winter Teletherm (Willow City, North Dakota).
The main plots in A and B show the average daily maximum and minimum temperature (black dots) along with a smoothed curve formed using a Gaussian Kernel (solid red). For all minimum temperature analyses, we wrap the year from July 1 to June 30. The main plots’ insets show the fraction of error-free recording for each year. Subplot i: Representation of the spectrum of maximum/minimum temperatures per day of the year. The black curve indicates the median, the blue area indicates lowest to first quartile, yellow the inter-quartile range, and red the fourth quartile. Subplot ii: Expansion of the inset around the Teletherm in the main plot. The dark gray vertical line indicates the Teletherm and the lighter gray region the Teletherm Period which we define as the days for which the smoothed maximum/minimum temperature curve is within 2% of the Teletherm’s temperature, relative to the dynamic range of the smoothed curve over the entire 365 days. Subplot iii: Robustness diagnostic showing how the Teletherm date varies as a function of Kernel width. We use 15 days, marked in red. See the main text for further details. See Fig 3 for four more extreme Teletherm examples. We provide Teletherm plots for the maximum and minimum temperatures for all 1218 stations in the Supporting Information (S1 and S2 Files) and in the paper’s online appendices at http://compstorylab.org/share/papers/dodds2015c.