First chapter of the online book “Meteorology and Oceanography for Sailors”. Description of the composition and layers of the atmosphere (Troposphere, Stratosphere, Mesosphere, Thermosphere and Exosphere). General concepts of interest to understand marine meteorology and oceanography.

General wind circulation in the North Atlantic, NE trade winds, equatorial calms (doldrums), tropical calms (horse latitudes), polar winds, squalls and their associated fronts and tropical cyclones (hurricanes).

ON-LINE Glossary of terms most commonly used internationally in relation to floating ice (sea ice and land ice) at sea, in relation to navigation. Includes a short description of the meaning of each of the terms.

Description of the analysis of weather on a sailboat, long term (Pilot Charts, publications, climatology), and short term (surface isobar maps and 24/48/72 hour forecasts, GRIB files, Passage Weather, weather warnings (GMDSS) and Weather Routing).

What is a GRIB weather file?, weather models that provide GRIB weather files, How to obtain GRIB weather on board? and considerations on the use of GRIB weather on board.