Temporal variability of visibility and its parameterizations in Ningbo, China

Area of Science:

• Environmental Science
• Atmospheric Science
• Air Quality Research

Background:

• Visibility reduction is a critical environmental issue, particularly in urban and suburban areas.
• Understanding the interplay between visibility, air pollutants, and meteorological factors is essential for effective environmental management.
• Ningbo, a key coastal city, experiences varying air quality and visibility conditions.

Purpose of the Study:

• To investigate the characteristics of visibility in Ningbo over a two-year period.
• To analyze the relationships between visibility, air pollutants (especially PM2.5), and meteorological parameters.
• To develop and validate predictive models for visibility based on air quality and weather data.

Main Methods:

• Continuous monitoring of visibility, meteorological data, and air pollutants from June 2013 to May 2015.
• Application of statistical methods, including Multiple Correspondence Analysis (MCA).
• Development of non-linear models combining multiple linear and exponential regressions.

Main Results:

• Mean visibility was 11.8 km, with 43.4% of days having visibility below 10 km.
• Visibility exhibited significant diurnal variations and was notably lower in winter.
• Visibility was found to be an exponential function of PM2.5 concentrations under specific relative humidity conditions.

Conclusions:

• Visibility in Ningbo is strongly influenced by air pollutant concentrations and meteorological conditions.
• The developed non-linear models effectively quantify the relationships between visibility, air quality, and weather parameters.
• These models offer a valuable tool for predicting and managing air quality and visibility in Ningbo.