BAMS has done it again. After claiming the number one spot for Impact Factor on the Thompson Institute for Scientific Information (ISI) ranking in 2008, BAMS came in first in the Meteorology and Atmospheric Sciences category once again in 2009.
The impact factor, or IF, is a measure reflecting the average number of citations to articles published in science and social science journals. Devised by Eugene Garfield, the founder of the ISI (now part of Thomson Reuters), the IF is calculated yearly and journals are ranked taking into account two years of citations. The total number of citations for BAMS in 2009 was 9,074 with an IF of 6.123.
The IF is primarily used to compare different journals within a field, with larger impact factors suggesting greater influence, or impact, in the field. Four other AMS journals placed in the top twenty with Journal of Climate coming in at number five, Journal of Atmospheric Sciences at thirteen, Journal of Hydrometeorology at fifteen, and Monthly Weather Review at twenty. The newest AMS journal, Weather, Climate, and Society will appear in the IF rankings for the first time in 2011 when there is sufficient citation data to calculate a score.