On the twilight zone between clouds and aerosols

Citations Over TimeTop 1% of 2007 papers

Abstract

Cloud and aerosols interact and form a complex system leading to high uncertainty in understanding climate change. To simplify this non‐linear system it is customary to distinguish between “cloudy” and “cloud‐free” areas and measure them separately. However, we find that clouds are surrounded by a “twilight zone” – a belt of forming and evaporating cloud fragments and hydrated aerosols extending tens of kilometers from the clouds into the so‐called cloud‐free zone. The gradual transition from cloudy to dry atmosphere is proportional to the aerosol loading, suggesting an additional aerosol effect on the composition and radiation fluxes of the atmosphere. Using AERONET data, we find that the measured aerosol optical depth is higher by 13% ± 2% in the visible and 22% ± 2% in the NIR in measurements taken near clouds relative to its value in the measurements taken before or after, and that 30%−60% of the free atmosphere is affected by this phenomenon.

Related Papers

• → The MODIS Aerosol Algorithm, Products, and Validation(2005)3,412 cited
• → Aerosol optical depth and Ångström exponent climatology at El Arenosillo AERONET site (Huelva, Spain)(2007)247 cited
• → An AERONET-based aerosol classification using the Mahalanobis distance(2016)125 cited
• → Assessment of Aerosol Modes Used in the MODIS Ocean Aerosol Retrieval(2012)5 cited
• → ELT site prospect in Morocco: aerosol characterization(2006)