Table 1. Coordinates and Time Period of Activity for the GNIP Stations Used in This Studya


Name	Latitude	Longitude	Time Period

Kano	12.05degreesN	8.53degreesE	1961-1973
Bamako	12.32degreesN	7.57degreesW	1962-1998
N'Djamena	12.13degreesN	15.03degreesE	1964-1995
Niamey	13.52degreesN	2.09degreesE	1992-1999
Assekrem	23.27degreesN	5.6degreesE	1993-2001
Fes	33.58degreesN	4.59degreesW	1994-2001
Sfax	34.43degreesN	10.41degreesE	1992-2001
Gibraltar	36.15degreesN	5.35degreesW	1962-2001
Algiers	36.78degreesN	3.05degreesE	1998-2001
Tunis	36.83degreesN	10.23degreesE	1968-2001

aBy comparison, the time periods for SCIAMACHY and TES are 2003-2005 and 2004-2008, respectively.