This study utilizes VIIRS DNB day-night band data to investigate the spatial derivative of upward atmospheric layer attenuation and artificial light at night (ALAN) over the United States, the Middle East, and the Indian subcontinent in 2017. It explores the feasibility of developing a gridded nighttime aerosol optical thickness (AOT) dataset. Additionally, the study evaluates the potential of using the NASA standard Black Marble nighttime lights product suite (VNP46) to estimate the spatial derivative of surface artificial light emissions, and discusses the sensitivity of nighttime aerosol retrieval to observational conditions as well as the application of different methods for estimating the spatial derivative of surface artificial light emissions. The research validates the retrieved AOD by comparing it with ground-based AOD data from AERONET sites and satellite-based AOD products, such as MODIS AOD and MISR AOD. There are certain aspects/details that require further clarification from the authors, and I have listed them in my comments below： 

1. The selection of aerosol types has a certain impact on the inversion accuracy. In this context, aerosol plumes in the Indian subcontinent primarily consist of a mixture of polluted haze, smoke, and pollutant aerosols (Line 224). How is this mixed aerosol type (aerosol composition) defined?

2. The lunar AERONET AOT data at 440, 675, 870, 1020, and 1640 nm (Line 152).  Why was the 700 nm value not obtained by fitting the 675 nm and 870 nm bands for the analysis in Figures 4-7?

3. Please discuss the influence of lunar radiation on the AOD nighttime inversion results in Section 4.5.

4. The 6S model requires satellite surface reflectance data as input, but the method for calculating the surface reflectance from VIIRS DNB remote sensing imagery is not explained.