SIO Upper Ocean Temperature climatology and Anomalies
The
climatologies include temperature, heat storage, and
mixed-layer depth, while the
anomalies include monthly heat storage.
They are served as datasets, including an interactive
viewer and downloadable data files.
Mixed-layer depth is defined as SST - 1.0C.
Annual temperature profile observation counts
YEAR | COUNT |
1955 | 41,958 | NODC NGOTS |
1956 | 45,978 |
1957 | 57,427 |
1958 | 67,380 |
1959 | 65,886 |
1960 | 68,758 |
1961 | 76,295 |
1962 | 82,125 |
1963 | 89,042 |
1964 | 83,430 |
1965 | 85,909 |
1966 | 93,860 |
1967 | 74,938 |
1968 | 74,305 |
1969 | 68,484 |
1970 | 59,781 |
1971 | 65,320 |
1972 | 60,205 |
1973 | 67,360 |
1974 | 71,294 |
1975 | 59,659 |
1976 | 60,606 |
1977 | 60,171 |
1978 | 61,217 |
1979 | 63,189 |
1980 | 63,715 |
1981 | 56,893 |
1982 | 54,920 |
1983 | 48,150 |
1984 | 50,863 |
1985 | 50,294 |
1986 | 49,072 |
1987 | 42,969 |
1988 | 26,260 |
1989 | 40,092 | GTSPP |
1990 | 13,039 |
1991 | 21,790 |
1992 | 29,515 |
1993 | 54,248 |
1994 | 51,520 |
TEMPERATURE CLIMATOLOGY AND ANOMALY ANALYSIS PROCEDURE
- Temperature profile databases used:
- 1955 to 1988: NODC Global Ocean Temperature/Salinity CD-ROM
data set.
- 1989 to 1994: Global Temperature/Salinity Pilot Project(GTSPP)
data set.
- Interpolate temperature profiles at inflection points to 15 standard
levels(0, 20, 40, 60, 80, 120, 160, 200, 240, 300, 400, 500, 600,
700 and 800 meters). Simple linear interpolation is used.
CLIMATOLOGY
- Calculate MONTHLY climatology at each standard level by BIN AVERAGING
absolute temperature profiles to a 5 Deg.(X) -by- 2 Deg.(Y) grid res-
olution. Only data from Jan. 1980 to Dec. 1989 was used.
The MONTHLY mean was calculated for each month from 1980 to 1989.
Each monthly mean is then summed over the 10 year period to form the
RAW climatological mean for the month.
- A Fourier analysis is performed using the first 2 harmonics(the
ANNUAL and BI-ANNUAL cycles) for each time sequence at each grid
location for each standard depth. The Fourier series is
y'(i) = [An * COS (2*n*pi*t/12) + Bn * SIN (2*n*pi*t/12)]
for n = 1 to 2 and
t = 0 to 11
The Fourier coefficients A1/B1, A2/B2 and the long-term ANNUAL mean
are written-out as grids at each standard level.
- Areas of missing data in the Fourier coefficient and long-term ANNUAL
mean fields are filled by zonal and meridional linear interpolation.
The following procedures are followed for the area filling,
- The maximum ZONAL no-data gap is 20 degrees.
- The maximum MERIDIONAL no-data gap is 10 degrees.
- New monthly climatology fields are constructed using the filled
Fourier coefficients and long-term ANNUAL mean.
ANOMALIES
- Temperature anomaly profiles are calculated using the reconstructed
monthly climatology. The climatology is BI-LINEARLY interpolated to
the location of each temperature profile and the anomalies calculated
at each standard level.
Profiles of ABSOLUTE, ANOMALOUS and CLIMATOLOGICAL temperature are
saved in MONTHLY files.
- Monthly Optimum Interpolation mapping of the temperature anomalies
is performed for each standard level(0 ==> 400M) for each month from
Jan. 1955 to Dec. 1994.
Decorrelation scales used for th O.I. mapping:
ZONAL(Lx) = 10 degrees
MERIDIONAL(Ly) = 5 degrees
TEMPORAL(Lt) = 90 days(from the 15th of each month).
- The O.I. mapped fields are filled in space and time. The spatial
filling procedure is performed first with the following limits,
- The maximum ZONAL no-data gap is 20 degrees.
- The maximum MERIDIONAL no-data gap is 10 degrees.
The temporal filling is done with Maximum Entropy Prediction based
on the algorithm by N. Andersen, 'On the Calculation of Filter
Coefficients for Maximum Entropy Spectral Analysis', 1974,
Geophysics, Vol.39, No. 1, pp69-72.
- Adjust the space/time filled mapped monthly anomalies by computing
the monthly MEANS of the ANOMALIES(over the period Jan. 1955 to
Dec. 1994) then subtracting these means(of the anomalies) from the
mapped fields.
Reference
The original dataset is kept
here.
The original dataset was produced by Ted Walker (
walker@canopus.ucsd.edu).