The European Space Agency (ESA) distributes plugins to atmospherically correct Sentinel-2 images.
Here are three ways on how to apply atmospheric correction in Sentinel-2 images.
1. Sen2Co
One of these is the Sen2Cor processor that is freely available as a plugin integrated in the Sentinel Application Platform (SNAP) software. Besides of the Bottom-of-Atmosphere reflectances (BOA) reflectance product, additional outputs such as Aerosol Optical Thickness (AOT) map, Water Vapor (WV) map, Scene Classification map and Quality Indicators data are generated. The atmospheric model of SEN2COR is based on the ATCOR model.
Download the current version of SNAP here.
Download the latest version of Sen2Cor here.
2. HLS or Harmonized Landsat Sentinel 2
Landsat and Sentinel-2 data represent the most widely accessible moderate-to-high spatial resolution multispectral satellite measurement.
Citation for HLS data set: Claverie, M., Ju, J., Masek, J. G., Dungan, J. L., Vermote, E. F., Roger, J.-C., Skakun, S. V., & Justice, C. (2018). The Harmonized Landsat and Sentinel-2 surface reflectance data set. Remote Sensing of Environment, 219, 145-161.
3. MACCS/MAJA
MACCS (Multi-sensor Atmospheric Correction and Cloud Screening) is a level 2A processor, which detects the clouds and their shadows, and estimates aerosol optical thickness (AOT), water vapour and corrects for the atmospheric effects.