ABSTRACT
This chapter shows how the meteorological observations contained in old ships' logbooks can help to improve our knowledge of the climate and to better quantify the ranges of natural variability of the climate system. It discusses the potential of logbook data in climate reconstruction for periods and areas poorly covered by other instrumental meteorological measurements. The earth's climate has experienced variations in time scales ranging from years to thousands of years. "Documentary records", based on written accounts of old weather by contemporary eyewitnesses, are currently considered an important source of meteorological data. One of the key systems of the global climate is the monsoonal circulation. Monsoons are usually defined as a seasonal reversal of the wind driven by changes in land-sea thermal contrast and accompanied by large changes in precipitation. On a world-wide scale, the major monsoon systems are the West African Monsoon and the Indo-Asian monsoon.
