**********************************************************************
*** Atmospheric H2 concentrations (ppbv) derived from flask       ***
*** samples collected at Macquarie Island, Australia               ***
*** Source: L.P. Steele                                            ***
***              P.B. Krummel                                      ***  
***              R.L. Langenfelds                                  ***
***              Commonwealth Scientific,                          ***
***              and Industrial Research Organisation,             ***
***              Aspendale, Victoria,                              *** 
***              Australia  3195                                   ***                   
***                                                                ***   
*** March 2003                                                     ***
***                                                                ***
**********************************************************************

Year	Jan.	Feb.	Mar.	Apr.	May	Jun.	Jul.	Aug.	Sep.	Oct.	Nov.	Dec.	Ann. Ave.

1992		525.2	523.78	522.54	519.83	515.67	513.58	512.21	510.53	513.57	517.44	518.39	
1993	521.5	524.03	522.8	519.72	515.16	511.06	509.82	508.69	507.75	510.21	514.51	520.12	515.45
1994	524.78	523.75	521.15	518.89	515.79	513.65	511.78	510.28	511.92	517.16	522.71	527.95	518.32
1995	532.43	532.43	529.75	527.01	521.43	517.47	516.32	514.62	517.66	523.9	528.43	532.09	524.46
1996	535.53	535.78	533.06	530.64	526.59	521.26	519.01	518.09	520.27	523.09	524.78	528.23	526.36
1997	531.41	532.79	533.41	533	528.59	522.06	516.97	514.86	515.74	521.51	527.96	531.82	525.84
1998	536.7	539.3	539.38	537.44	532.75	529.56	528.76	527.84	527.48	530.84	535.99	539.66	533.81
1999	542.07	543.18	542.69	539.69	534.2	528.73	526.3	525.77	528.05	534.12	537.25	538.19	535.02
2000	541.14	542.41	540.32	535.74	530.57	525.84	524.16	524.02	524.23	527.82	532.79	535.72	532.06
2001	538.41	539.89	537.02	532.18	527.82	523.4	521.18	520.2	520.82	525.77	529.84	531.95	529.04

Monthly values are expressed in parts per billion per volume (ppbv) and reported in the CSIRO94 H2 scale. 
Monthly values were calculated as the mean of the daily values from a smooth curve fit to the data using 
the curve-fitting routines described by Thoning et al., 1989 (J. Geophys Res. 94, 8549-8565). Annual 
values are the arithmetic means of the 12 monthly values.