Oceanic Nino Index, Equatorial Southern Oscillation Index and Dipole Mode Index
enso
A data frame with variables:
For ONI and SOI, this is a 3-month average. Jan value is average of Dec-Jan-Feb. Qtr would be denoted JFM.
The ONI index value
The SOI index value
The DMI index value
The MEI index value
The NAO index value
The PDO index value
The AMO index value
The ONI index is 3 month running mean of ERSST.v5 SST anomalies in the Niño 3.4 region (5°N-5°S, 120°-170°W)], based on centered 30-year base periods updated every 5 years. The ONI was downloaded as follows:
require(XML) require(RCurl) require(httr) oni=read.table("http://www.cpc.ncep.noaa.gov/data/indices/oni.ascii.txt", stringsAsFactors=FALSE)
The SOI used is the Equatorial SOI monthly. The data were downloaded with the following code.
soi=read.table("http://www.cpc.ncep.noaa.gov/data/indices/reqsoi.for", stringsAsFactors=FALSE)
The DMI is the monthly Dipole Mode Index. The DMI (also IOD index) is defined by the SSTA difference between the western Indian Ocean (10°S–10°N, 50°E–70°E) and the southeastern Indian Ocean (10°S–0°, 90°E–110°E). The data were downloaded from the NOAA Earth Systems Research Laboratories with the following code.
dmi=read.table("https://www.esrl.noaa.gov/psd/gcos_wgsp/Timeseries/Data/dmi.long.data", skip=1, nrows=149)
The NAO is the monthly North Atlantic Oscillation Index. The North Atlantic Oscillation (NAO) index is based on the surface sea-level pressure difference between the Subtropical (Azores) High and the Subpolar Low. The data were downloaded from the NOAA Climate Prediction Center with the following code.
nao = read.table("ftp://ftp.cpc.ncep.noaa.gov/wd52dg/data/indices/nao_index.tim", skip=9, nrows=length(1950:2018)*12)
The PDO is the monthly Pacific Decadal Oscillation Index and the AMO is the Atlantic Multidecadal Oscillation. The PDO is an index of the sea surface temperature anomalies over the North Pacific Ocean. The AMO is based on sea-surface temperature oscillations in the North Atlantic Ocean. The data were downloaded from the NOAA Physical Sciences Laboratory with the following code.
pdo = read.table("https://psl.noaa.gov/tmp/gcos_wgsp/data.143.131.2.6.325.11.4.55", skip=0, nrows=length(1948:2017)*12) amo <- read.table("https://psl.noaa.gov/tmp/gcos_wgsp/data.143.131.2.6.325.11.25.33", skip=0, nrows=length(1948:2017)*12)
Saji NH, Yamagata T (2003). “Possible impacts of Indian Ocean Dipole mode events on global climate.” Climate Research, 25(2), 151--169. doi: 10.3354/cr025151 , https://doi.org/https://doi.org/10.3354/cr025151.
van den Dool HM, Saha S, Johansson Å (2000). “Empirical orthogonal teleconnections.” Journal of Climate, 13, 1421--1435.
Mantua NJ, Hare SR, Zhang Y, Wallace JM, Francis RC (1997). “A Pacific interdecadal climate oscillation with impacts on salmon production.” Bulletin of the American Meteorology Society, 78, 1069--1079.
Newman M, Alexander MA, Ault TR, Cobb KM, Deser C, Di Lorenzo E, Mantua NJ, Miller AJ, Minobe S, Nakamura H, Schneider N, Vimont DJ, Phillips AS, Scott JD, Smith CA (2016). “The Pacific Decadal Oscillation, Revisited.” Journal of Climate, 29(12), 4399--4427. doi: 10.1175/JCLI-D-15-0508.1 , https://doi.org/https://doi.org/10.1175/JCLI-D-15-0508.1.
Enfield DB, Mestas-Nuñez AM, Trimble PJ (2001). “The Atlantic Multidecadal Oscillation and its relation to rainfall and river flows in the continental U.S.” Geophysical Research Letters, 28(10), 2077--2080. doi: 10.1029/2000GL012745 , https://doi.org/https://doi.org/10.1029/2000GL012745.