A helpful glossary of terms associated with weather and climate.

# A B C D E F G H I J K L M N O P Q R S T U V W X Y Z


The process of applying modern data assimilation techniques to historical periods. A consistent scheme is applied to periods of decades (for climate monitoring and associated products) or longer (for climate change studies). Reanalyses are important since they provide weather and climate information across the region, not just where there are observations. They give a more complete and coherent picture of the weather than can be obtained from observation data alone.