Related Experiment Video
Updated: Apr 1, 2026

Measurement of Aerosols Optical Thickness of the Atmosphere using the GLOBE Handheld Sun Photometer
Published on: May 29, 2019
Estimation of aerosol optical depth at different wavelengths by multiple regression method
Fuyi Tan1, Hwee San Lim2, Khiruddin Abdullah3
1School of Physics, Universiti Sains Malaysia, 11800, Gelugor, Penang, Malaysia. fuyitan@yahoo.com.
A new model estimates aerosol optical depth (AOD) using ground measurements, enabling continuous air quality monitoring. This tool accurately predicts AOD, aiding in tracking aerosol variations when satellite data is unavailable.
Area of Science:
- Atmospheric Science
- Environmental Monitoring
- Remote Sensing
Background:
- Aerosol optical depth (AOD) is crucial for understanding atmospheric conditions and climate.
- Continuous monitoring of AOD is challenging, especially during periods without satellite retrieval data.
- Ground-based measurements offer potential for AOD estimation.
Purpose of the Study:
- To develop and validate a predictive model for estimating AOD.
- To utilize routine ground-based measurements for AOD monitoring.
- To assess aerosol characteristics during non-retrieval times.
Main Methods:
- Statistical analysis to establish relationships between ground measurements (API, visibility, humidity, temperature, pressure) and CIMEL sun photometer AOD.
- Development of a calibrated AOD prediction model with wavelength-specific coefficients.
- Validation of the model using statistical tests and comparison of aerosol size estimations.
Main Results:
- The proposed model accurately predicted AOD across a wide range of wavelengths (340 nm to 1020 nm).
- The model demonstrated consistency with measured AOD data in characterizing aerosol size distribution.
- Penang was found to be dominated by fine mode aerosols in 2012-2013 based on both measured and predicted AOD.
Conclusions:
- The developed AOD prediction model is a viable tool for regular aerosol variation monitoring.
- Routine ground measurements can effectively supplement satellite data for AOD estimation.
- The model aids in understanding aerosol properties and their temporal variations.
Related Concept Videos
Multiple Regression
Farmers can use multiple regression to determine the crop yield based on more than one factor, such as water availability, fertilizer, soil properties, etc. Here, the crop yield is the response or dependent variable as it depends on the other independent variables. The analysis requires the construction of a scatter plot...
Regression Analysis
In regression analysis, a regression equation is determined based on the line of best fit– a line that best fits the data points plotted in a graph. This line is also called the regression line. The algebraic equation for the regression line is called the regression equation. It is represented as:
Residuals and Least-Squares Property
If the observed data point lies above the line, the residual is positive, and the line underestimates the actual data value for y. If the observed data point lies below the line, the residual is negative, and the line overestimates the actual data value for y.
The process of fitting the best-fit...
Attenuated Total Reflectance (ATR) Infrared Spectroscopy: Overview
The ATR process begins by directing a beam...
Precipitation Titration: Endpoint Detection Methods
In the Volhard method, a standard excess of AgNO3 is first added to the...
UV–Vis Spectroscopy: Beer–Lambert Law

