Climatic Research Unit : Data

Mediterranean Oscillation Indices (MOI)

NEW (April 2021): all updated to 2020:

moi1.output.dat covers Algiers/Cairo

moi2.output.dat covers Gibraltar/Israel

Web_WeMOi-2020.txt covers Padua/Cadiz (starts 1821)

Please do not ask me to produce monthly MOI data: it is ambiguous, as it can be calculated in different ways. If you need monthly MOI then feel free to calculate it from the daily data presented here.

Note that early NCEP data (1948-1967) has a problem relating to SLP, this will affect derived products such as these MOI indices.

Note that the previous versions (1958 to 2010) did not include leap year days (29/02) for 2004 and 2008 due to a fault in the programs. This has been corrected for the updated files.

The MOI is defined by Palutikof et al. (1996) and Conte et al. (1989) as the normalized pressure difference between Algiers (36.4°N, 3.1°E) and Cairo (30.1°N, 31.4°E) A second version of the index can be calculated from Gibraltar's Northern Frontier (36.1°N, 5.3°W) and Lod Airport in Israel (32.0°N, 34.5°E) (Palutikof et al., 2003). Here data is presented for both variants, using pressure interpolated (16 point Bessel) from NCEP/NCAR reanalysis data.

More information about the Western MOI data (WeMOi) may be found here. Users of WeMOi should also reference:

New Daily File format (MOI only)
for year = 1948 to 2020
  for month = 1 to 12
    format(F5.0, 2F3.0, F7.3) year, month, day, value
Missing values represented by -99.99 (MOI)

WeMOi format is one line per year, with year plus 12 monthly values (tab-separated). 11 header lines. Missing values represented by -999

Filename SizeDescription
moi1.output.dat 506 kilobytesMOI: Algiers and Cairo
moi2.output.dat 506 kilobytesMOI: Israel and Gibraltar
Web_WeMOi-2020.txt 29 kilobytesWeMOi: Padua and Cadiz, monthly

Previous updates

July 2020: Updated to 2019

November 2018: Added WeMOi; Updated to 2017

February 2017: Updated to 2016

August 2015: Updated to 2014

November 2014: Updated to 2013

October 2013: Updated to 2012

May 2011: Indices are now daily. Initial data files run from 1958 to 2010

Thanks to Andrew Harding for updating the index. Future updates are planned. Please contact me ( if you wish to access the software routines that calculate the MOI indices from the NCAR Reanalysis Data.

The previous monthly index is still available to allow comparisons to be made:

Old Monthly File format (MOI)
for year = 1958 to 2000
  for month = 1 to 12
    format(i4,i3,f7.2) year, month, value
Missing values represented by -99.99

Filename SizeDescription
moac.dat 8 kilobytesMOI: Algiers and Cairo
moig.dat 8 kilobytesMOI: Israel and Gibraltar

Last updated: April 2021, Ian Harris.

These datasets are made available under the Open Database License.
Any rights in individual contents of the datasets are licensed under the
Database Contents License under the conditions of Attribution and Share-Alike.
Please use the attribution Climatic Research Unit, University of East Anglia