Aleutian Low Pressure Index (ALPI)

correct URL: http://www.pac.dfo-mpo.gc.ca/science/species-especes/climatology-ie/cori-irco/indices/alpi-eng.txt

This index measures the relative intensity of the Aleutian Low pressure system of the north Pacific (December through March). It is calculated as the mean area (kmē) with sea level pressure <= 100.5 kPa and expressed as an anomaly from the 1950-1997 mean. A positive index value reflects a relatively strong, or intense Aleutian Low.

The index was completely regenerated using a new method in 2015.  The new method produces ALPI values that are comparable to previously published values (1900-2008), and there is no difference in the periods with positive or negataive values.

To make use of this index, you are requested to cite the manuscript (below).  For more information, please see the manuscript, or contact Dr. Jackie King (Jackie.King@pac.dfo-mpo.gc.ca).

Correct citation:

Surry, A.M.  and King, J.R.  2015.  A New Method for Calculating ALPI: the Aleutian Low Pressure Index. Can. Tech. Rep. Fish. Aquat. Sci. 3135: 31 + v p.

YEAR	ALPI
1900	1.30
1901	-1.69
1902	0.03
1903	-4.93
1904	-3.83
1905	-1.04
1906	-2.79
1907	-5.46
1908	-1.70
1909	-2.44
1910	-2.55
1911	-3.22
1912	-0.08
1913	-1.19
1914	0.70
1915	-1.38
1916	-3.62
1917	-2.49
1918	-0.79
1919	0.26
1920	-3.63
1921	-0.93
1922	-3.00
1923	-1.90
1924	0.59
1925	-0.60
1926	4.23
1927	0.87
1928	0.66
1929	1.61
1930	-2.10
1931	2.91
1932	-2.20
1933	-3.04
1934	2.95
1935	-0.75
1936	2.66
1937	-3.37
1938	0.11
1939	0.32
1940	6.42
1941	4.58
1942	2.18
1943	-2.97
1944	0.87
1945	3.00
1946	1.70
1947	-2.12
1948	-2.61
1949	-1.60
1950	-1.93
1951	-1.83
1952	-2.87
1953	2.20
1954	-2.32
1955	-2.62
1956	-4.68
1957	-1.60
1958	2.12
1959	-2.16
1960	-0.35
1961	2.92
1962	-1.63
1963	2.32
1964	0.74
1965	-1.62
1966	-1.88
1967	-0.17
1968	-0.40
1969	-2.72
1970	3.69
1971	-2.25
1972	-4.51
1973	-1.62
1974	1.04
1975	-1.84
1976	-1.12
1977	3.03
1978	2.32
1979	-0.99
1980	1.67
1981	5.09
1982	-3.21
1983	6.69
1984	1.68
1985	-1.64
1986	5.20
1987	3.62
1988	1.21
1989	-2.68
1990	-0.87
1991	0.45
1992	2.14
1993	-0.94
1994	-0.63
1995	1.59
1996	0.86
1997	0.49
1998	4.58
1999	0.13
2000	0.26
2001	1.50
2002	-0.37
2003	2.80
2004	2.83
2005	0.90
2006	0.37
2007	0.55
2008	-1.10
2009	-3.96
2010	4.08
2011	-0.62
2012	0.27
2013	-0.12
2014	-0.57
2015	0.34