This topical volume of the Journal of Pure and Applied Geophysics utilizes new information not previously accessible for fog related research. It focuses on surface and remote sensing observations of fog, various numerical model applications using new parameterizations, fog climatology, and new statistical methods. The results presented in this special issue come from research efforts in North America and Europe.

"This topical volume of the Journal of Pure and Applied Geophysics utilizes new information not previously accessible for fog related research; it focuses on surface and remote sensing observations of fog, various numerical model applications using new parameterizations, fog climatology, and new statistical methods. The results presented in this special issue come from research efforts in North America and Europe, mainly from the Canadian Fog Remote Sensing And Modeling (FRAM) and European COST-722 fog/visibility related projects.

Fog and Boundary Layer Clouds: Introduction.- Obituary.- Fog Research: A Review of Past Achievements and Future Perspectives.- Microphysical Observations and Mesoscale Model Simulation of a Warm Fog Case during FRAM Project.- Dynamical Nighttime Fog/Low Stratus Detection Based on Meteosat SEVIRI Data: A Feasibility Study.- Inferring Low Cloud Base Heights at Night for Aviation Using Satellite Infrared and Surface Temperature Data.- Analysis of Fog Probability from a Combination of Satellite and Ground Observation Data.- The Impact of Vertical Resolution in the Explicit Numerical Forecasting of Radiation Fog: A Case Study.- A One-dimensional Ensemble Forecast and Assimilation System for Fog Prediction.- Quality Assessment of the Cobel-Isba Numerical Forecast System of Fog and Low Clouds.- Seasonal Sensitivity on COBEL-ISBA Local Forecast System for Fog and Low Clouds.- Can Sea Fog be Inferred from Operational GEM Forecast Fields?.- Implementation of a Single-Column Model for Fog and Low Cloud Forecasting at Central-Spanish Airports.- Synoptic Classification and Establishment of Analogues with Artificial Neural Networks.- Probabilistic Visibility Forecasting Using Neural Networks.- Climatological Tools for Low Visibility Forecasting.- Marine Layer Stratus Study.