Figure 2

While rising temperatures affect all inhabitants, wind direction makes the ozone pollution burden heavier for wealthy northeastern communities. (a) Daily maximum temperature in Santiago. For each day of year (DOY), we formed datasets using daily maximum temperatures over the period 2000–2021. The mean (white line) and standard deviation (bounds of the gray shading) of these datasets are shown in the plot. The daily maximum temperature for 2017 is also shown (red line). The dotted rectangular box highlights a period of very warm days in January 2017. (b) Daily maximum temperature in Santiago averaged over two periods: 1961–1990 (blue line) and 2012–2021 (red line). Bold lines correspond to the 30-day centered moving averages. (c) Progress of summer ‘very warm” days in Santiago over the period 1961–2021. Bold line corresponds to the 7-year centered moving averages. We consider a summer day to be “very warm” if the corresponding maximum temperature falls above the 90th percentile of the daily base climatology (built up by using daily maximum temperatures measured over a 30-year base period 1961–1990; see “Methods”). (d) Daily average wind speed in Santiago. For each day of year (DOY), we formed datasets using values of the daily average wind speed over the period 2019–2021. The mean and standard deviation (σ) of these datasets are shown in the plot. The daily average wind speed for 2019 is also shown (red line). (e) Hourly average wind speed in Santiago. For each hour, we formed datasets using values of the hourly average wind speed over the period 2019–2021. The mean (white line) and standard deviation (bounds of the gray shading) of these datasets are shown in plots. (f) Vector array map showing 10-m summer wind speed and direction averaged from 13 to 20 h UTC over the period 2011–2020. Air temperature and wind speed are from the weather station that the Chilean Weather Service (DMC) operates since early twentieth century downtown Santiago; measurements are available at https://climatologia.meteochile.gob.cl/application/diario/visorDeDatosEma/330020. In the case of the vector array map, data from ERA5⁴⁶ were used. Plots were generated using Python’s Matplotlib library⁵⁰.