Surface ozone trends at El Arenosillo observatory from a new perspective

Area of Science:

• Atmospheric Chemistry and Physics
• Climate Science
• Environmental Monitoring

Background:

• Surface ozone trends are crucial for understanding air quality and climate change.
• Long-term monitoring is essential to identify changes in atmospheric composition.
• Investigating ozone drivers requires analyzing meteorological and atmospheric data.

Purpose of the Study:

• To analyze 22-year surface ozone trends at El Arenosillo observatory (2000-2021).
• To investigate the influence of temperature and weather pattern shifts on ozone trends.
• To explore seasonal and diurnal variations in surface ozone trends.

Main Methods:

• Statistical analysis of daily ozone averages and percentiles (5th, 95th).
• Analysis of surface temperature trends (daily averages, 5th, 95th percentiles).
• Examination of weather pattern shifts using 2m temperature and 850 hPa geopotential height trends.
• Monthly and hourly ozone trend analysis.

Main Results:

• Significant increase in background surface ozone (1.2 ± 0.3 ppb decade⁻¹).
• Observed regional warming trends (0.5 ± 0.2 °C decade⁻¹).
• Detected strengthening of the Azores anticyclone and regional warming.
• Distinct monthly ozone trends, with increases in Dec-Jan and decreases in Jul-Aug.
• Complex hourly ozone trends, with inverse daily cycles in spring-autumn and winter peaks.

Conclusions:

• Surface ozone trends are influenced by changing weather patterns and a warming climate.
• The strengthening Azores anticyclone and regional warming likely contribute to observed ozone trends.
• Further investigation of daily and hourly ozone trends is recommended for a comprehensive understanding.