ARL Weekly News – February 9, 2024

Publications

Published: Comparative analysis of aerosol vertical characteristics over the North China Plain based on multi-Source observation data

Wang, F., Z. Li, Q. J., X. Ren, H. He, Y. Tang, X. Dong, Y. Sun, and R. R. Dickerson, Comparative analysis of aerosol vertical characteristics over the North China Plain based on multi-Source observation data, Remote Sensing, 16, 609, 2024, https://doi.org/10.3390/rs16040609

Abstract: In this paper, multi-source observation, such as aircraft, ground-based remote sensing, and satellite-retrieved data, has been utilized to compare and analyze the vertical characteristics of aerosol optical properties and the planetary boundary layer height (HPBL) over the North China Plain (NCP) region during May–June 2016. Aircraft observations show the vertical profiles of aerosol absorption coefficients (σabs), scattering coefficients (σsca), and extinction coefficients (σext) gradually decrease with altitude, with their maximum values near HPBL. The vertical profiles of σext depended most on the vertical distribution of measured σsca, indicating a significant contribution of scattering aerosols. In addition, the prominent characteristic of the inverse relationship between σext and moisture profile could serve as a reference for predicting air quality in the NCP region. The lower layer pollution during the field experiment was likely caused by the accumulation of fine-mode aerosols, characterized by the vertical distribution of the Ångström exponent and the Aerosol Robotic Network (AERONET) products. Typically, HPBL derived from aircraft and surface Micro Pulse Lidar (MPL) was approximate, while the predicted HPBL by meteorological data indicates an underestimation of ~192 m. Aerosol optical depth (AOD) calculated from aircraft and ground-based remote sensing (such as MPL and AERONET) experienced a strong correlation, and both of them exhibited a similar tendency. However, the AOD retrieved from satellites was significantly larger than that from aircraft and ground-based remote sensing. Overall, the inversion algorithm, cloud identification algorithm, representativeness of the space, and time of the observation may lead to an overestimation or underestimation of AOD under certain circumstances. This study may serve as a re-evaluation of AOD retrieved from multi-source observations and provide a reference to uncover the actual atmospheric environment in the NCP regions.

Published:  Ozone pollution episodes and PBL height variation in the NYC urban and downwind coastal areas during LISTOS 2019

Wu, Y., K. Zhao, X. Ren, R. R. Dickerson, J. Huang, M. J. Schwab, P. Stratton, H. Daley, D. Li, and F. Moshary, Ozone pollution episodes and PBL height variation in the NYC urban and downwind coastal areas during LISTOS 2019, Atmos. Environ., 320, 120317, 2024, https://doi.org/10.1016/j.atmosenv.2023.120317.

Abstract: In summer, frequent ozone (O3) episodes occur in New York City (NYC) and coastal areas along Long Island Sound (LIS) due to complex interplay of urban pollutants transport, land-sea breezes, and chemistry. The Long Island Sound Tropospheric Ozone Study (LISTOS) was carried out to address this issue; here we present an integrated analysis of the diurnal variation of planetary-boundary-layer height (PBLH) and O3 in the NYC urban and coastal area during LISTOS in summer 2019. A persistent O3 episode (July 28–31, 2019) is investigated which shows much higher O3 (90–120 ppb with 5-min average maximum) along the North-shore of Long Island (NLI) than the NYC urban and South-shore of Long Island (SLI). We evaluate the PBLH estimate with a multi-platform observation in the complex coastal environment, and compare the PBLH diurnal variation in the NYC urban to coastal areas. The results indicate lower PBLH in the mid-morning and noon in the NLI than the NYC urban area.