Year: 2020
Type: article
Abstract: We investigated the variability of the aerosol scattering (σsp; 1974–2015) and absorption (σap; 2000–2015) coefficients at the Mauna Loa Observatory using surface in situ measurements. Although σsp decreased during the morning (1.85 ± 3.43 Mm–1 at 550 nm, 8–11 local standard time [LST]), it increased during the afternoon (3.72 ± 7.63 Mm–1 at 550 nm, 14–17 LST) due to the development of thermally induced boundary layer winds. No distinct diurnal variation was observed in σap. The obvious increase in σsp and σap during the spring under free troposphere conditions (8–11 LST) is attributed to long-range-transported aerosols from Asia, especially dust and pollution aerosols from Northeast Asia and biomass burning aerosols from Southeast Asia. Accordingly, σsp increased from 1974 till 2015 (at 1.89% year–1), whereas no significant trend was noted for either σsp or σap from 2000 till 2015. An increasing trend for σsp prevailed in air masses originating in Northeast Asia (+0.51 Mm–1 decade–1).
Source: Aerosol and Air Quality Research
Language: English
Subfield: Global and Planetary Change
Field: Environmental Science
Domain: Physical Sciences
SDG: Climate action
Open Access status: gold
Estimated APC paid: $2,090
Awards: G2374800707, G7255679605
OpenAlex ID: W3015968596