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The recovery and re-calibration of a dataset of vertical aerosol extinction profiles of the 1963/64 stratospheric aerosol layer measured by a searchlight at 32° N in New Mexico, US, is reported. The recovered dataset consists of 105 aerosol extinction profiles at 550 nm that cover the period from December 1963 to December 1964. It is a unique record of the portion of the aerosol cloud from the March 1963 Agung volcanic eruption that was transported into the Northern Hemisphere subtropics. The data-recovery methodology involved re-digitizing the 105 original aerosol extinction profiles from individual Figures within a research report, followed by the re-calibration. It involves inverting the original equation used to compute the aerosol extinction profile to retrieve the corresponding normalized detector response profile. The re-calibration of the original aerosol extinction profiles used Rayleigh extinction profiles calculated from local soundings. Rayleigh and aerosol slant transmission corrections are applied using the MODTRAN code in transmission mode. Also, a best-estimate aerosol phase function was calculated from observations and applied to the entire column. The tropospheric aerosol phase function from an AERONET station in the vicinity of the searchlight location was applied between 2.76 to 11.7 km. The stratospheric phase function, applied for a 12.2 to 35.2 km altitude range, is calculated from particle-size distributions measured by a high-altitude aircraft in the vicinity of the searchlight in early 1964. The original error estimate was updated considering unaccounted errors. Both the re-calibrated aerosol extinction profiles and the re-calibrated stratospheric aerosol optical depth magnitudes showed higher magnitudes than the original aerosol extinction profiles and the original stratospheric aerosol optical depth, respectively. However, the magnitudes of the re-calibrated variables show a reasonable agreement with other contemporary observations. The re-calibrated stratospheric aerosol optical depth demonstrated its consistency with the tropics-to-pole decreasing trend, associated with the major volcanic eruption stratospheric aerosol pattern when compared to the time-coincident stratospheric aerosol optical depth lidar observations at Lexington at 42° N. [ABSTRACT FROM AUTHOR]

Aerosols, the tiny suspended particles in the atmosphere, are a widely studied topic around the world due to their effects on the Earth's radiation budget, climate change, and human health. Knowledge of the spatial and temporal distribution of aerosols is essential to assess air pollution and predict potential climate change. This study measured aerosol optical depth (AOD) and altitude-dependent aerosol extinctions in Nassau, The Bahamas simultaneously using a camera-based imaging lidar (CLidar). The bistatic geometry of the setup which consisted of a wide-angle lens fitted to a charge-coupled device (CCD) camera, allowed for the measurement of extinctions at all altitudes at once without requiring expensive timing electronics common to lidars. A case study was conducted on November 5, 2018. The top of the boundary layer beyond which aerosol extinction was nearly zero was detected at ~ three km above sea level. Due to the excellent resolution of the CLidar at lower altitudes, variations of aerosol concentrations within the boundary layer are efficiently detected. Optical depth was measured using the same CLidar camera at the same time, utilising star photometry, and was found to be 0.043 ± 0.040. The value falls within the range of assumed values of AOD near the regions obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS) Aqua satellite. [ABSTRACT FROM AUTHOR]