We provide time series of the Tropical Sea Surface Anomalies and their forecasts, using Linear Inverse Modeling. This timeseries collection is described on our website.

Details on calculations of the indices:

  • Nino3.4 SST Index is averaged in the box 6N-6S, 170W-120W (see map).
  • Nino4 SST Index is averaged in the box 6N-6S, 160E-150W (see map).
  • Indian Ocean SST Index is averaged in the box 2N-2S, 70E-90E (see map).
  • Hawaii SST index is averaged in the box 22N-18N, 150W-140W (see map).
  • Caribbean SST Index is averaged over the area - see map.
  • North Tropical Atlantic SST Index is averaged over the area - see map.
  • Equatorial Atlantic SST Index is averaged in the box 6N-6S, 30W-10E (see map).
  • South Tropical Atlantic SST Index is averaged in the box 6S-18S, 30W-10E (see map).

These indices are presented in the ASCII format, suitable for PSD Interactive Plotting and Analysis Pages.

Time Series Format

The format for all time series is:
year1 yearN

year1 janval febval marval aprval mayval junval julval augval sepval octval decval

year2 janval febval marval aprval mayval junval julval augval sepval octval decval

...

yearN janval febval marval aprval mayval junval julval augval sepval octval decval

missing_value

In this collection we include:

Seasonally Smoothed Tropical Sea Surface Anomalies Indices , are calculated from COADS data (1951-1991) and NCEP Surface Marine (1991-present). The data are smoothed 3-months running monthly mean anomalies relative to 1951-2000 base period, projected on 20 leading EOFs. More description.
Please, note: in order to use the Time Series presented on this website in the PSD Interactive Tools for "Custom" use the pathname: /Datasets/Timeseries/Filename, where the "Filename" is taken from the tables. For example: /Datasets/Timeseries/CAR_ersst.data.
  • Nino3.4 Index (Nina34_ersst.data)
  • Nino4 Index (Nina4_ersst.data)
  • Indian Ocean Index (IND_ersst.data)
  • Hawaii index (HAW_ersst.data)
  • Caribbean Index (CAR_ersst.data)
  • North Tropical Atlantic Index (NTA_ersst.data)
  • Equatorial Atlantic Index (EA_ersst.data)
  • South Tropical Atlantic Index (STA_ersst.data)
  • The pattern correlation of the Optimal Structure with the SST anomaly pattern eight months earlier (COROPT)

References:

  • Penland, C., and T. Magorian, 1993: "Prediction of Niño 3 Sea-surface Temperature Anomalies using Linear Inverse Modeling,"J. Climate, 6, 1067-1075.
  • Penland, C., and P. D. Sardeshmukh, 1995: "The optimal growth of tropical sea surface temperature anomalies," J. Climate, 8, 1999-2024.
  • Penland, C., and L. Matrosova, 1998: "Prediction of tropical Atlantic sea surface temperatures using Linear Inverse Modeling" J. Climate, 11, 483-496.
  • Penland, C., and L. Matrosova, 2004: "Getting Rid of El Nino." Proc. 17th Conf. on Probability and Statistics, Seattle, WA, Jan. 2004.
  • Penland, C., and L. Matrosova, 2006: "Studies of El Nino and interdecadal variability in tropical sea surface temperatures using a nonnormal filter." J. Climate, 19, 5796-5815.
  • Michael A. Alexander, Ludmila Matrosova, Cecile Penland, James D. Scott, Ping Chang "Forecasting Pacific SSTs: Linear Inverse Model Predictions of the PDO.", J. Climate, in press.