To determine the higher AQI value between the 1-hour and 8-hour data for ozone, we need to convert the ozone concentrations in parts per million (ppm) to the corresponding Air Quality Index (AQI) values. The AQI is calculated based on specific breakpoints defined by the Environmental Protection Agency (EPA). Since the formula for calculating the AQI differs for 1-hour and 8-hour ozone data, we need to calculate the AQI for both time frames and compare the values.
For the 1-hour ozone data of 0.163 ppm, we can use the following formula to calculate the corresponding AQI:
AQI = (AQI_high - AQI_low) * (C - C_low) / (C_high - C_low) + AQI_low
Using the breakpoints provided by the EPA for 1-hour ozone:
AQI_low = 0
AQI_high = 500
C_low = 0.125 ppm
C_high = 0.164 ppm
C = 0.163 ppm
Plugging in these values into the formula, we can calculate the AQI for the 1-hour data:
AQI_1hour = (500 - 0) * (0.163 - 0.125) / (0.164 - 0.125) + 0
= 500 * 0.038 / 0.039 + 0
≈ 487
For the 8-hour ozone data of 0.082 ppm, we use a different set of breakpoints provided by the EPA for 8-hour ozone:
AQI_low = 0
AQI_high = 500
C_low = 0.065 ppm
C_high = 0.084 ppm
C = 0.082 ppm
Calculating the AQI for the 8-hour data:
AQI_8hour = (500 - 0) * (0.082 - 0.065) / (0.084 - 0.065) + 0
= 500 * 0.017 / 0.019 + 0
≈ 447
Comparing the two AQI values, we find that the higher AQI value is 487, which corresponds to the 1-hour data of 0.163 ppm.