JISAO data
Tropical land temperature anomaly time series, 1851-June 1997
ENSO tends to warm the tropics, and this index captures this tendency over the land regions. The average is taken over 30N-30S, GM-120E and 150E-GM, so excluding New Guinea. The data was provided by Phil Jones of the Unversity of East Anglia.

Historical record: 1851-1997
Image of time series.
The index has been smoothed for this figure with successive 11- and 9-point running means. The larger amplitudes in the 1850s are probably due to the small number of grid boxes contributing to the average (the number of grid boxes contributing are documented below). This series exhibits year to year variability, and also warm temperatures (approximately 0.3C) between 1880 and 1920. The latter signal is consistent with the warming experienced in the Northern Hemisphere high latitudes during the same period.

Modern record: 1950-97
Image of time series.
The index has been smoothed with a 3-point running mean for this figure. The series exhibits warmer temperatures during the larger ENSOs, but also general warm conditions in the 1980s and 1990s.

Regression of surface temperature anomalies onto the CTI (sign only) 1950-79Image of map of tropics with dots and circles plotted for land points as follows.
The surface temperature data is regressed onto an index of eastern equatorial Pacific SST anomalies. With the exception of New Guinea and northern Australia (longitudes 120-150E) the entire tropics warms (denoted by dots) during ENSO warm episodes.

The index is linked here in (in degrees C) in MATLAB ".mat" format. ["load troplandtempanom18511997.mat" will load the data in the variable "landtempanom" and the number of gridboxes contributing into "landtempnum."]

References

  • gridded land temperature anomalies:
    Jones, P. D., 1994: Hemispheric surface air temperature variations: A reanalysis and an update to 1993. J. Climate, 7, 1794-1802.
  • the index on this page is being written up in a paper on the chronology of ENSO in the tropics by myself and Mike Wallace.
    Digital values of the index in hundredths of degrees Celsius. Missing data are indicated by blanks.
           JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC
 1851   56   22 -200   32  119   94   86   86   90  137   71   81
 1852   46  147  -45   -3   59   94   76   76   80   47   21  -14
 1853  -30  105  158  141  160  134   51  102  115   94  158  102
 1854  227   38  130  -16   83  114  146   77   28   17   53   55
 1855   73   34   51   75   91  -32    3   64   15  -68   41  -68
 1856   23   21  -20  -31  -50  -15  -16  -20   -9    8  -10   17
 1857   13   83   38   37  -64   -6   -7  -65  -43  -99  -23  -82
 1858   18   14  -39   29  -61 -103  -55   41   50  -88   22  -82
 1859  -82   -6    1  133  124  -89  105   70   14  118 -105   -5
 1860   34   34   81   14    9   13   13   49   12  119   -9  -27
 1861   -8  -16  -75   43  -80  -96  -20   76   -6  -24   78   -2
 1862   13  -51   30   37   22  -10  -57  -97  -55   -3  -33  -12
 1863  -42  -84  -22   97  -84  -15   16  -25   -9  -35  -88   -7
 1864   30  -93  -98   45 -224   -1  -69   32 -999  -10 -999   37
 1865   33  138   78   16   30  -23  -10    5   76   77  -30  -34
 1866   56   56  -19  -15  -44  -45  -38    9   12  -36  -28 -100
 1867  -35    5   72   -6   54    9  -13  -15   47   49  -52  -48
 1868   99  282   56  -52   34    3  -14   60  117   87   39   54
 1869   42   95   69    1   45   32   21   43   52   35   26  -56
 1870    2   79   18   49    1   51   27   -1  -42   38    8  -67
 1871   13   85   11  -23   20  -44   32   35  -36  -34  -21  -71
 1872   39  -23   19   11    2  -10   25   63   -1   15   18  -28
 1873   21   95  -18   13   90   47  -20   50   39   32   24  -54
 1874 -120  -57  -17  -14  -75  -45   35    9   -3  -55  -70  -11
 1875   14   32  -22  -12  -42  -88  -16  -64    2   -7  -18  -42
 1876  -27  -13   -1   16    3   36   10   -7   -5  -59  -51  -44
 1877    5  -95   -9  -38  -38   53  101   69   61   53   63   32
 1878  -53   31   34    7  -36   80   71   23   38   36    3   -4
 1879   -3   39  -37   46   28  -51   22  -16  -28  -41  -81  -60
 1880  -13  -58   68   46  -33   10  -20   49  -44    5  -12  -33
 1881  -41   39  -18   24   13  -45  -26    4   49   18  -39   29
 1882   25  -55   -7  -46  -43  -73  -63   15   -9   23  -73  -13
 1883  -43  -91  -43   -1  -50  -34  -56   15  -38  -24  -92  -96
 1884   -6  -84    8  -21  -44  -44  -29   24  -30  -88 -108  -52
 1885   -2 -102  -33  -84 -106  -54  -35  -18   14    8    9   -3
 1886  -18  -52   -4  -30  -23  -51  -38   -4   -8   -4   -3  -36
 1887  -36  -59  -23  -34  -38  -45  -58  -34  -48  -64  -37  -38
 1888  -52  -24   18    9  -45  -23  -17  -18  -17   -7  -29   -9
 1889   18   -2    0    5   15  -11    3  -17  -21  -48  -64    0
 1890   15   -9  -44  -22  -33  -77  -63  -79  -52  -72  -87  -36
 1891  -39  -65 -123  -30  -39   13   12  -25  -18  -33  -13    2
 1892  -13   36   -1   39  -27  -48  -30  -52  -42  -38  -67  -68
 1893  -63 -128 -130  -33  -98  -97  -46  -21  -37  -53  -50  -42
 1894  -38  -40  -47  -23  -24  -60  -55  -53  -28  -29  -42  -29
 1895  -31  -56  -44  -31  -26  -36  -11  -14   -4  -41   -4  -13
 1896    9  -19    7   25    4  -34    4   12   33   17   16    1
 1897   15   22    1   19   18   15   16   -1   -4    8  -16  -37
 1898  -38  -51  -21    0  -21  -16  -36  -42  -33  -26  -10  -46
 1899  -72  -64   -2  -27  -22  -54    2   37   31    2  -13   -1
 1900   -5    2   33   23   -2   37   14    7   -3   -2   -3    4
 1901  -12  -45  -15  -15    0   48   17    8    8    8  -13  -23
 1902  -15  -16   26   22   27   22   17    8    5  -35  -14   -2
 1903  -33  -55  -44  -26  -26    1    6  -18  -19  -51  -75  -67
 1904  -60  -58  -58  -41  -56  -40  -31  -34  -25  -48  -49  -63
 1905  -64 -143  -85  -72  -16    6  -13   -9    4   14    2  -22
 1906  -21  -36  -36  -14   15  -32  -12  -34   -9  -30  -32  -17
 1907   -1  -58  -55  -78  -71  -39  -17  -40  -23  -19  -32  -40
 1908  -27  -42  -36  -26  -24   -1  -36  -29  -14  -40  -56  -37
 1909  -13  -33   -4  -46  -37  -39  -22   -4  -15  -30    2  -36
 1910  -41  -46  -61  -50  -40  -19  -25  -13  -21  -57  -61  -57
 1911   -9  -57  -75  -54  -62  -66  -30  -41  -27  -29  -36  -20
 1912    0    8  -16  -11    4    7  -30  -21  -21  -19  -39  -46
 1913  -35  -37  -90  -21  -31  -44    1   13  -13  -13  -25  -28
 1914   31  -19  -24  -33    1   18    5  -16    4   -6   18  -13
 1915    1    2  -32    9   15   10   24   32    2   40   31  -16
 1916  -14  -12   28    5   -9  -52  -19  -25  -11  -17  -33  -49
 1917   -8  -25  -61  -62 -119  -42  -25  -26  -36  -40  -45  -41
 1918 -105  -62  -54  -76  -42  -50    9  -27    3   22   16   -6
 1919   45   22   19   22    5    3   -2  -15  -29   -3  -17   -6
 1920    6  -33  -26  -19  -30  -37  -28  -21    6    5   10  -13
 1921   -1  -21    2   18   13  -22  -36  -14  -20  -21  -29   17
 1922   20   25    8   12    3  -18   -1  -10  -19  -31   -9   -7
 1923   12  -38   -3  -22  -23   11  -29  -17    0  -20   13   14
 1924   22   11   36    3  -17    5  -14  -17  -25  -22  -23  -24
 1925  -90  -58   -9   -1  -19  -27  -18   14   -9  -25    3    8
 1926   29   55   11  -15   -3   30    0   18   23   16   -9   15
 1927    2  -18  -41  -23  -11  -10  -12  -14    0    8   23   30
 1928   24  -12   14   13   -4   -7    1  -23   -7    1    1    0
 1929    8  -16   -7    3   -2  -15  -28  -27    4   -2   -6  -33
 1930  -52   12  -26    4  -14    2   -9  -23    8   -9   16   57
 1931   52   51   26   37   11    6   10   37  -18   17   -1   26
 1932   15   -8  -10   17   -5   21    2   -3    6   13   43    1
 1933    9   25   10   -7    4  -20   -7    0  -17   -6   -6    1
 1934  -46  -44  -43   -2    8   31   18   23   13  -19   -3   16
 1935   10  -15   29  -24    6   11    6  -17  -11   18   23   42
 1936   13   25    5    5   -1   -9    1   -8  -17   -4   19   18
 1937   -1   33   15    2    6   31    5   21   11   14   45   30
 1938   35    3   -3    9    9   -5    5    3   17   20  -17   11
 1939   34   -9  -35  -51   18   14   10   21  -28   21    0   14
 1940   18   26  -18   -7   17   22   25   18   13   11   32   72
 1941   62   57   54   81   48   37   42   58    8   73   39   60
 1942   46   73   45   40   11   28  -22    5   16   -4   53   19
 1943   14  -37  -23  -41    1  -29    7  -31   -5   35   19   32
 1944    7   -2   -5    0    6   47   43   47   32   38   27   40
 1945   28  -26  -15   27  -20    5   15   38   28    4   26    9
 1946   34   35    5   26   12   -6  -21  -10   17   10   44   27
 1947   30   52   15   19   22   34    4    9   -2   -2   23   21
 1948    4    6  -43    7   21   16   17    0    3  -10  -37   15
 1949   10  -37    4  -12   20   14    7    1    4   -6    5   -6
 1950   -8  -42  -32  -14  -15    3  -21  -36  -23  -40  -31  -22
 1951  -33  -45    4  -37   19    8   21   22   29   48   12  -12
 1952   47   17   19   15   17   -7   15    4  -13    0   -9   19
 1953   42   45   23   11   17   -1  -18   21    5    0   12   -7
 1954    4   34    8   -5    4  -22  -35  -18  -12  -26   16  -12
 1955   13   19   -2  -28  -16  -11  -39  -25   -9  -18    2  -28
 1956  -46   19    2  -21  -44  -42  -33  -30  -24  -43  -22  -25
 1957  -28  -53  -27  -25    1   -3    5   18   18   14   56   52
 1958   57   13   55   85   24   38   22  -12   20   -3   31   45
 1959   17  -31    5   37   15   32   24  -19  -11    4   -2    3
 1960   16   37  -13  -12  -25   23   -9   30   13   27   10   63
 1961   17  -49  -17   16   42   12    7    8   -6   -1  -27  -34
 1962  -40   -3    3   -1  -14   -7   -5   10   19    6   46   17
 1963   20   38  -22    1  -28    3   32   41   48   39    5   15
 1964   -7   -3   50   25   -6  -23  -38   -8  -29  -46  -41  -39
 1965   -3    7  -29  -49  -12   14   16    8   14    8    4   -4
 1966   56   19   -3    9   13   27   40   15   -4   27   37    3
 1967  -34  -15  -49   -6   23  -20  -17   -9   -9   -4  -25   -8
 1968  -36  -50  -43  -61  -48  -36    6   20    1    6   27   39
 1969   20   65   97   44   47   48   23   23   44   30   30   31
 1970   47   42    2   41   30   24    9   15   -1    3  -10   -8
 1971  -20  -30    9  -28  -22  -48  -11  -28  -21  -62  -46  -28
 1972  -19  -43   -2  -17    9   23   38   16   40   34   10   37
 1973   48   75   48   61   36   40   16  -10    7   20  -34  -27
 1974  -56  -50  -29  -10  -12   -7  -25  -21  -34  -11  -22  -63
 1975  -53  -12  -20    0    0   -6  -50  -34  -21  -35  -40  -50
 1976  -55  -40  -55  -47  -46  -41  -21  -18  -23   -9  -13   21
 1977   -7   -4    6   -9  -23   11   32    1   11    0    7   -5
 1978    3   24    4   -1   14  -22    0  -23  -29   -2  -15   13
 1979   36   15    7   26    0   -7   15   39   -3   34   32   13
 1980   34   19   26   63   58   13    9   15   -8   16   21    8
 1981  -14    6   15   17   10   -6  -32   26   -8   -7  -13   32
 1982   23  -19  -16    1   -8   14   39   15   24   18  -25  -16
 1983  -17   31    7   44   75   33   62   34   23   -4   18    0
 1984  -30   -5   28   14   46   -5   10    6   -4   16  -11   -7
 1985   42  -12   39   -6   34    7  -15   14    0    8   22    5
 1986   -1   23    8   57   40   33    6   23   -7  -10    3  -16
 1987   36   65   27   39   46   38  106   63   56   57   78   63
 1988   55   48   54   59   57   26    9   40   33   19   11   14
 1989  -56  -52  -24    7    1   15   -1   31    5    3   38   17
 1990   36   -6   -1   51   26   35   -8   42   18   62   96   63
 1991   37   54   41   46   34   39   22   13   24   24  -17   17
 1992   -6  -24   11   39   25   69  -15    7   12   15  -19   22
 1993   -5   12   14   41   43   50   37   29   21   48   62   40
 1994   39   10   22   45   73   28    3   15   19   32   41   26
 1995   15   31   39   29   49   77   67   70   53   68   42   42
 1996   55   44   41   14   45    4   22   34   36   25    7   48
 1997   39  -19   -2  -24   35   50
    Number of 5-degree grid boxes contributing to the index, 1851-1997.
    Image shows <10 grid boxes for 1851-1870, linear increase to 150 by 1950, max of 190 in 1960s, decreasing trend to 150 in 1990s.

           Jan  Feb  Mar  Apr  May  Jun  Jul  Aug  Sep  Oct  Nov  Dec
 1851    2    2    2    2    2    2    2    2    2    2    2    2
 1852    2    2    2    2    2    2    2    2    2    2    2    2
 1853    3    3    3    3    3    3    2    3    2    2    2    3
 1854    3    3    2    3    2    2    2    2    2    2    2    2
 1855    2    2    2    2    3    3    3    3    3    2    3    3
 1856    3    4    3    3    5    5    6    5    4    5    4    4
 1857    5    4    4    5    6    4    5    3   10    8    3    2
 1858    4    2    5    6    2    3    7    5    5    3    5    5
 1859    2    3    3    3    2    5    4    5    2    6    4    6
 1860    9    5    3    5    5    5    6    7    3    2    4    4
 1861    4    2    3    3    4    4    4    4    2    3    3    7
 1862    6    2    3    4    5    6    6    2    3    4    3    2
 1863    3    3    4    1    4    8    7    5    4    5    4    4
 1864    8    3    3    5    1    2    2    2    0    4    0    1
 1865    3    3    2    7    4    3    1    5    6    2    8    6
 1866    7    4    3    5    5    4    3    6    6    6    4    5
 1867    9    5    3    3    4    5    4    4    5    4    5    6
 1868    3    2    4    4    7    4    6    6    3    5    6    5
 1869    8    2    3    6    7    5    6    8    6    8   10   10
 1870   11    8   13    7   10    7    8    9    7    6    4    5
 1871    8    5    5    6   11    9    3    7    6    4   11    9
 1872    4    9   13   18   11   12    8    5   12    9    9   10
 1873   11    4    9   13   12   12   10   13   14    8   14    8
 1874    5   12   12   10   11   14   13   11   14   15   15   15
 1875   14   10   18   15   17   17   10   18   11   14   16   17
 1876   25   22   24   21   21   19   23   20   22   21   22   22
 1877   20   22   24   24   23   23   22   23   23   23   24   24
 1878   25   26   27   25   27   28   27   29   28   29   28   29
 1879   28   30   26   25   29   32   25   30   27   28   27   26
 1880   31   31   30   30   29   31   30   27   29   34   31   28
 1881   26   30   31   30   30   30   31   26   27   28   31   31
 1882   27   29   29   32   32   30   32   29   30   32   26   29
 1883   29   27   30   29   31   30   30   30   28   27   27   26
 1884   27   30   32   29   32   29   29   31   30   29   32   31
 1885   32   31   32   31   29   28   30   28   30   29   31   32
 1886   35   33   34   34   32   32   36   34   35   36   32   33
 1887   30   32   32   31   30   33   32   27   31   29   29   30
 1888   35   32   35   34   31   33   28   29   32   31   30   33
 1889   35   39   34   32   34   37   34   37   34   34   35   39
 1890   36   37   39   38   37   36   38   37   37   35   37   36
 1891   37   38   35   34   36   36   32   35   34   33   37   36
 1892   35   39   38   38   39   35   38   40   38   36   43   38
 1893   41   39   39   45   41   38   41   40   40   39   39   42
 1894   41   41   41   42   41   39   41   42   44   42   43   41
 1895   42   38   43   42   42   42   42   44   40   38   40   41
 1896   47   43   43   45   40   44   44   43   46   45   43   39
 1897   46   47   46   42   47   46   44   51   50   44   42   44
 1898   48   52   49   50   47   49   51   51   49   55   51   48
 1899   47   49   50   49   50   49   49   50   46   47   49   49
 1900   45   46   42   44   46   44   43   43   45   44   45   46
 1901   53   53   54   53   51   50   53   53   51   54   51   55
 1902   59   62   62   62   66   61   60   63   59   67   59   63
 1903   67   61   66   61   62   61   60   68   63   63   61   63
 1904   60   66   67   63   65   64   64   68   67   66   64   67
 1905   71   74   72   72   69   72   75   76   73   73   71   75
 1906   74   76   77   75   77   79   74   79   77   79   77   79
 1907   78   79   79   76   73   79   80   79   80   78   80   81
 1908   81   79   81   80   79   77   76   81   78   81   78   73
 1909   77   76   76   78   76   78   79   77   74   77   77   81
 1910   81   84   80   82   84   85   83   84   85   83   79   81
 1911   78   81   85   85   84   81   84   84   82   83   83   84
 1912   86   82   85   83   85   83   84   84   84   82   87   83
 1913   85   84   85   85   85   86   83   85   82   81   86   85
 1914   82   84   80   85   81   79   75   70   70   69   71   69
 1915   63   64   62   65   66   64   65   67   67   69   67   67
 1916   70   70   69   73   71   73   72   74   75   74   74   71
 1917   76   74   72   71   68   73   68   71   74   71   70   72
 1918   74   73   69   73   77   68   72   72   73   75   70   71
 1919   71   69   73   71   72   66   68   71   74   75   75   72
 1920   71   72   73   74   72   76   74   77   74   77   76   77
 1921   81   85   81   88   89   87   87   84   86   90   89   94
 1922   91   98   91   93   96   92   94   89   93   92   96   93
 1923   99  100  100   96  101  101  103  101  101  100  100   95
 1924  101  101  101  101  102  100  102  103  100  107  102  105
 1925  105  100  102  103  102  106  105  105  103  106  107  109
 1926  103  103  105  104  103  102  103  103  102  101  104  106
 1927  107  106  108  107  108  107  107  109  106  105  108  106
 1928  104  108  105  100  105  102  101  105  104   99  100  101
 1929  106  105  101  100  102  103  101  102  103  101  102  101
 1930   98   96  101  103  100  100  102   98   98   98   97   99
 1931  100  102  103  107  106  105  108  105  106  108  110  110
 1932  110  108  104  105  105  105  103  107  108  103  108  109
 1933  110  110  112  117  115  111  112  114  116  115  120  121
 1934  121  119  117  120  120  119  121  119  120  120  118  118
 1935  118  119  116  114  115  115  116  119  119  117  120  118
 1936  119  119  120  118  119  117  121  120  117  116  121  120
 1937  118  121  118  119  118  118  120  119  118  115  118  118
 1938  115  118  120  120  119  119  116  120  117  118  118  120
 1939  117  119  119  119  114  115  118  117  113  114  116  115
 1940  106  109  106  107  105  108  107  107  103  106  106   98
 1941  125  136  134  129  128  134  131  128  126  128  124  121
 1942  133  134  134  132  130  137  138  131  125  130  132  130
 1943  136  137  137  136  127  130  129  133  128  131  127  129
 1944  139  133  135  134  132  136  134  133  131  133  134  136
 1945  134  136  134  128  127  133  126  128  129  129  127  131
 1946  142  142  143  139  141  144  145  143  144  144  146  141
 1947  149  147  150  146  148  146  146  149  146  146  147  146
 1948  144  144  145  142  147  145  146  150  143  147  148  148
 1949  146  147  147  147  145  147  146  143  147  146  144  143
 1950  146  144  146  145  143  146  148  150  149  148  149  148
 1951  169  172  170  168  170  169  169  174  172  175  173  174
 1952  170  171  169  170  172  171  173  171  172  173  174  171
 1953  174  172  174  174  173  174  175  174  172  172  174  175
 1954  172  172  173  175  174  174  174  175  175  174  175  173
 1955  174  175  173  175  176  174  172  175  173  175  175  175
 1956  176  177  177  177  174  173  175  175  175  177  175  175
 1957  177  173  174  177  177  175  175  175  175  175  175  174
 1958  174  177  175  175  175  175  177  177  177  176  177  177
 1959  177  177  176  177  176  176  177  177  177  177  175  175
 1960  174  175  176  176  177  177  177  177  177  177  177  177
 1961  182  182  185  181  182  187  184  183  183  181  187  182
 1962  182  185  183  181  183  183  184  187  186  187  183  186
 1963  184  186  186  183  186  186  183  186  186  185  186  185
 1964  186  186  186  185  186  186  186  187  188  188  186  184
 1965  185  185  186  185  183  185  180  187  186  186  188  186
 1966  184  183  186  186  184  187  188  185  185  188  188  187
 1967  188  188  189  186  188  188  188  186  188  188  185  186
 1968  187  180  188  188  186  187  188  187  183  185  188  186
 1969  186  188  186  186  186  188  188  188  188  185  187  186
 1970  186  188  188  188  188  187  186  174  179  183  187  185
 1971  188  184  184  182  186  186  183  183  185  188  185  183
 1972  186  187  182  181  181  181  172  182  180  181  170  178
 1973  183  181  176  179  179  178  177  181  179  179  179  178
 1974  186  186  187  187  188  182  178  182  183  177  182  176
 1975  181  183  182  180  181  178  170  169  164  166  163  158
 1976  169  169  171  169  170  168  167  164  160  161  156  151
 1977  168  165  167  168  168  169  169  164  162  164  160  160
 1978  171  168  172  162  169  167  160  171  157  160  156  157
 1979  157  153  167  161  163  163  141  166  163  154  148  155
 1980  157  156  146  153  155  166  154  146  148  149  147  138
 1981  164  173  171  161  165  160  164  162  167  162  159  160
 1982  164  165  162  170  158  165  158  155  167  169  168  168
 1983  152  170  165  171  171  168  166  165  171  169  169  168
 1984  163  169  168  165  164  157  167  166  164  160  166  159
 1985  169  175  177  172  162  162  165  162  168  167  171  161
 1986  170  172  166  178  174  157  163  160  171  162  170  161
 1987  172  169  172  172  153  167  172  170  166  168  161  169
 1988  162  164  169  162  165  159  158  157  161  155  167  165
 1989  169  168  153  164  166  149  161  155  153  148  151  154
 1990  143  148  152  148  145  145  138  156  138  139  145  125
 1991  157  146  141  138  136  138  128  138  136  145  119  110
 1992  140  124  121  130  144  133  135  139  131  138  129  141
 1993  135  135  138  147  136  130  145  141  145  148  124  121
 1994  144  148  111  145  138  144  148  137  151  150  151  143
 1995  133  132  159  154  139  128  143  138  146  133  141  138
 1996  144  140  133  132  138  144  140  144  148  143  133  154
 1997  137  148  127  111  120  115    0    0    0    0    0    0
    August 1998
    Todd Mitchell (mitchell@atmos.washington.edu)
    JISAO data