CSU Atlantic Multi-Decadal Oscillation (AMO) index In 2008, Phil Klotzbach and Bill Gray published a paper in Journal of Climate discussing a newly-developed Atlantic Multi-Decadal Oscillation index that utilized a combination of two predictors: 1) Sea surface temperatures (SSTs) in the far North Atlantic from 50-60°N, 50-10°W and 2) sea level pressures (SLPs) in the North Atlantic from 0-50°N, 70-10°W. At present, the index is calculated by weighing the SST component as 60% of the index and the SLP component as the remaining 40%. All values are standardized using the 1981-2010 climatological average as a baseline. Real-time monthly values are calculated from the NCEP/NCAR Reanalysis and are typically updated by the 5th of the following month.
Standardized monthly values of the Klotzbach and Gray (2008) AMO index from 1950-present
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Year
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
1950
-0.06
-0.12
0.09
0
0.94
0.59
0.65
0.16
-0.52
-0.35
0.32
-0.15
1951
-0.04
-0.06
0.71
0.74
1.03
1.8
0.92
0.16
0.7
0.13
0.04
-0.2
1952
-0.45
0.6
1.31
0.32
1.43
1.36
0.81
1.26
0.83
1.09
1.21
1.35
1953
0.98
0.96
0.73
1.65
1.93
0.45
0.19
0.05
0.32
-0.13
-0.42
0.14
1954
0.13
0.25
0.69
-0.4
0.87
0.47
0.42
0.83
-0.34
0.16
-0.04
-0.09
1955
1.29
0.77
1.12
1.17
1.12
1.18
0.82
0.6
-0.13
0.57
1.73
1.3
1956
1.29
1.13
1.02
1.39
-0.05
-0.48
0.39
0.1
0.22
-0.2
0.15
-0.03
1957
-0.2
0.48
1.33
0.43
0.84
1.06
0.98
0.36
0.92
0.23
0.42
-0.28
1958
0.69
1.4
1.68
0.67
0.71
1.4
1.4
1.21
1.11
-0.1
0.24
0.6
1959
0.83
0.18
0.19
0.56
0.9
0.53
-0.31
0.84
0.48
-0.03
-0.36
-0.11
1960
0.58
0.92
0.73
0.5
1.11
0.33
0.57
0.7
-0.2
0.88
0.45
-0.34
1961
-0.21
-0.13
0.24
1.34
0.33
-0.29
0.28
-0.23
-0.06
-0.59
0.38
0.94
1962
-0.33
-0.35
1.19
0.12
0.67
0.15
0.38
-0.38
-0.06
-0.06
-0.03
0.28
1963
0.76
0.75
0.45
1.53
-0.72
0.51
0.52
-0.38
-1.02
-0.24
0.25
0.17
1964
0.52
1.27
0.82
-0.37
0.57
0.85
-0.26
0.14
-0.31
-0.73
0.11
0.06
1965
0.47
0.8
1.02
0.57
1.13
0.26
-0.05
0.21
-0.2
0.16
-0.13
0.36
1966
1.52
1.6
0.79
1.55
-0.02
0.1
-0.07
0.71
0.68
0.82
-0.13
0.37
1967
0.67
0.62
-0.01
0.43
-0.21
-0.58
-0.67
-0.83
-0.43
-0.88
-0.44
-0.08
1968
-0.16
0.76
-0.25
0.2
-0.02
-0.1
-0.61
-0.24
-0.4
0.32
0.78
0.18
1969
0.71
0.98
1.08
-0.17
0.29
0.13
-0.63
-0.53
-1.07
-0.28
-0.59
-0.44
1970
0.95
-0.47
0.29
0.28
-0.38
-0.94
-0.88
-0.4
-0.34
-0.58
-0.41
-0.2
1971
0.55
-0.17
0.09
0.2
-0.19
-0.14
-0.11
-0.67
-0.43
-0.54
-0.62
-0.53
1972
-0.39
-0.58
-0.61
-0.45
-1.18
-1.62
-1.32
-1.23
-0.68
-0.79
-0.8
-1.1
1973
-0.94
-1.29
-0.69
-0.03
-0.46
-0.65
-0.89
-0.7
-0.57
-0.22
-0.04
-0.68
1974
-0.67
-0.56
-0.61
-1.05
-0.52
-0.36
-1.13
-1.05
-1.35
-1.64
-0.69
-1.04
1975
-0.92
-0.56
-0.63
-0.41
-0.04
-0.17
0.31
-0.09
-1.03
-0.62
-0.94
-0.48
1976
-0.54
-0.34
-0.58
-0.5
-0.98
-0.73
-0.86
-0.96
-0.53
-0.53
-0.92
-0.76
1977
-0.09
-0.08
0
-0.34
0.27
0.08
0.06
-0.2
-0.36
-0.47
-0.67
0
1978
-0.55
1.18
-0.01
0.47
-0.42
-1.18
0.02
-0.67
-0.38
-0.57
-1.03
0.5
1979
0.35
0.87
-0.33
0.17
0.29
-0.13
-0.9
-0.12
-0.28
0.04
-0.43
-0.3
1980
0.23
0.21
-0.04
0.11
1.11
-0.26
0.07
0.26
-0.93
-0.47
0.56
-0.27
1981
-0.23
-0.23
1.03
0.03
0.19
0.69
-0.1
-0.05
0.24
-0.72
0.14
0.72
1982
0.59
-0.11
-0.88
-0.66
-0.77
0.01
-0.53
-1.11
-1.34
-1.12
-1.75
-1.91
1983
-1.82
-0.92
-1.05
-0.99
-0.93
-0.65
-0.21
-1.13
-0.73
-1.54
0.13
-0.41
1984
-1.43
-1.42
-0.96
-0.29
-1
-0.97
0.18
-0.14
-0.11
-1.28
-0.76
-1.48
1985
-0.62
-0.76
-0.83
-0.7
-0.62
-0.67
-1
-1.39
-0.52
-0.89
-0.33
-0.4
1986
-1.18
-0.33
-1.51
-1.21
-1.06
-1.46
-1.26
-0.7
-0.03
-0.88
-2.07
-2.01
1987
-0.44
-0.29
-0.66
-0.73
-0.76
0.04
0.77
1.28
0.25
-1.06
-0.85
0.38
1988
-0.63
-0.65
-0.38
0.65
-0.13
-0.13
-0.87
-0.35
-0.35
-0.23
0.52
0.09
1989
-0.55
-1.18
-1.23
-1.35
-1.33
-0.51
-0.82
-0.1
-0.61
-0.75
-0.57
0.6
1990
-1.35
-1.29
-1.86
-2.05
-0.2
-1.14
-0.88
-1.25
-0.95
-0.47
-0.1
-0.73
1991
-1.6
-1.51
-0.46
-1.23
-0.99
-0.25
0.13
-1.02
-0.97
-1.16
-1.07
-0.87
1992
-0.36
-0.93
-1.19
-1
-1.2
-0.69
-0.54
-2.16
-2.04
-0.92
-1.06
-1.33
1993
-1.59
-1.6
-1.48
-1.18
-0.52
-0.68
-0.57
-0.96
-0.46
-0.41
-1.02
-1.56
1994
-1.59
-1.36
-1.46
-1.85
-1.09
-1.58
-1.72
-1.27
-0.84
0.55
0.22
-0.97
1995
-1.22
-1.33
-1.66
-0.56
0.39
0.46
1.33
1.07
-0.22
0.25
0.24
0.75
1996
0.81
-0.44
-0.38
0.43
0.28
-0.54
-1.07
-0.53
0.95
0.27
-0.33
0.42
1997
0.72
-0.48
-0.48
1.03
0.64
1.17
0.59
0.28
1.05
2.07
1.95
1.75
1998
0.45
0.46
0.05
0.3
0.22
0.82
0.86
0.7
1.77
0.76
0.43
0.14
1999
-0.47
-0.28
-0.09
0.12
0.09
-0.76
0.19
0.89
0.65
-0.21
-0.05
-0.19
2000
-0.36
-1.11
-0.05
-0.26
-0.28
-1.06
0.43
0.33
0.9
-0.79
0.27
0.31
2001
0.13
-0.08
0.66
-0.34
0.11
0.68
0.53
0.22
1.17
0.72
0.43
1.27
2002
0.75
-0.03
-0.4
-0.76
-0.89
-1.24
-1.46
-0.4
0.54
0.99
0.21
0.83
2003
0.55
-0.03
-0.12
0.13
-0.46
0.33
-0.35
0.07
0.53
1.22
1.13
0.84
2004
1.32
0.71
0.14
-0.09
-0.75
-0.35
-0.11
0.1
0.09
0.8
0.74
0.48
2005
-0.04
0.06
1.37
0.51
0.88
1.65
0.71
1.05
0.77
0.99
0.34
1
2006
0.72
0.77
1.01
0.43
0.71
0.02
0.34
1.21
1.8
1.97
1.14
0.05
2007
0.32
0.95
-0.14
0.65
-0.14
0.82
1.56
0.81
1.07
1.21
1.11
0.65
2008
0.08
-0.09
-0.3
0.2
1.22
1.07
0.69
1.43
0.34
-0.16
-0.15
0.06
2009
0.15
0.13
-0.02
-0.58
-1.31
0.17
0.58
0.06
-0.81
0.96
0.19
0.59
2010
0.53
1.69
0.65
1.08
1.34
1.3
1.17
1.7
2.61
1.97
1.81
2.33
2011
1.76
1.02
0.23
-0.25
-0.81
-0.59
-0.39
0.54
0.2
0.2
0.28
-1.04
2012
-0.81
-0.59
-0.65
-0.26
-0.07
1.5
1.96
1.67
0.99
1.69
0.58
0.67
2013
0.44
0.21
1.3
0.1
-1.09
-1.1
-0.26
0.28
0.44
1.55
0.3
-0.19
2014
-0.3
-0.55
-1.12
-0.94
-1.08
0.08
-0.26
1.15
0.67
0.56
-0.1
-1.2
2015
-1.56
-1.47
-1.88
-1.81
-2.24
-2.37
-0.76
-0.87
-0.26
-0.22
-0.57
-1.39
2016
-0.86
-1.72
-1.74
-1.64
-1.43
-0.32
-0.07
0.5
-0.16
0.25
0.17
-0.18
2017
-0.58
0.08
-0.61
-0.81
0.22
0.06
-0.89
0
0.31
0.16
0.39
0.33
2018
-0.61
-1.29
-0.5
-1.33
-2.03
-1.06
-2.01
-1.39
-0.81
-0.21
0.09
-0.2
2019
-0.48
-1.21
-1.87
-1.35
-0.34
-0.34
1.87
1.27
0.66
0.78
0.19
0.31
2020
-0.66
-1.3
-1.9
-0.75
-0.63
-0.85
-0.04
0.79
0.03
-0.42
-1.11
-0.97
2021
-0.14
-0.06
-0.76
0.25
-0.50
-1.17
-0.19
0.40
0.83
1.00
0.37
0.62
2022
-0.09
-0.81
-0.84
0.19
0.03
-0.07
0.00
0.63
2.03
1.13
0.44
0.20
2023
-0.42
-0.30
0.49
0.26
-0.19
2.09
0.77
1.38
1.72
1.85
0.62
0.13
2024
0.39
0.27
-0.13
0.01
0.58
0.28
0.40
0.09
0.67
1.20
