An integrated drone-based platform with novel correction methods for accurate vertical profiling of black carbon

Abstract

Equivalent black carbon mass concentrations were measured using a portable Aethalometer (MicroAeth AE51, eBC_AE51) and evaluated against refractory BC measurement obtained from a Single-Particle Soot Photometer (SP2, rBC_SP2). Correction methods were proposed to improve AE51 measurements by considering the non-linearity of light attenuation (ATN) due to the accumulation of BC particles (i.e., rBC loading effect) and the interference in ATN measurements caused by non-refractory BC particles (i.e., non-BC loading effect). First, a catalytic stripper was used to heat the sampling line to 350 °C, minimizing the impact of non-BC sampling. This allowed for the correction of the non-linearity of ATN due to the rBC loading effect. After applying the correction formula derived from this process to the measured eBC_AE51, further correction was applied to account for the filter loading effect of non-BC, estimated from atmospheric measurements through an unheated sampling line. This study introduces an innovative system for accurately quantifying high-resolution vertical profiles of BC mass concentration. By combining data from the AE51 and a miniaturized optical particle counter, the system applies precise corrections to enhance measurement accuracy at various altitudes. This integrated approach provides a robust framework for reliable atmospheric BC profiling, addressing challenges in pollutant characterization and transport analysis.