Mean Mixolimnion Temperature (MMT) of Ongeim'l Tketau, Palau.

MMT is correlated with sea-surface temperatures, three months later, in the Niño 3.4 region of the Pacific (Martin et al. 2005). If this relationship is maintained in the long-term, MMT may be useful for predicting El Niño-Southern Oscillation (ENSO) conditions. Temperatures in °C.

YEAR
MONTH
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
1999
31.6
31.7
32.0
32.5
32.1
31.7
32.4
32.0
33.2
32.8
32.6
31.4
2000
31.5
31.5
31.6
32.0
32.2
31.9
31.7
31.4
32.2
32.1
31.5
31.6
2001
31.7
30.7
30.6
31.1
31.7
31.4
31.4
30.5
31.3
31.4
31.3
30.7
2002
30.4
30.3
30.4
30.9
31.2
31.0
30.5
29.5
29.8
30.4
31.3
30.9
2003
29.8
29.8
30.5
31.0
31.0
30.5
30.8
30.8
30.7
31.1
31.1
30.7
2004
30.0
30.7*
30.3*
30.5*
30.8*
30.4
30.9*
30.3
30.8
30.1
31.2
31.1
2005
30.0
29.4
30.4
30.4
30.7
31.3
31.6
31.1
30.6
31.7
31.7
31.9
2006
31.7
31.3
30.7
30.8
31.0
31.4
30.6
30.3
31.1
30.6
31.0
31.0
2007
30.3
                 

 

Notes:

* MMT estimated from regression: For February-May and July 2004, MMT was estimated from HOBO thermograph data, recorded at 30 minute intervals at 6 m and 11 m, averaged for one 24-hour period per month near the middle of each month to replicate the Dec-Jan 2004 sampling regime. Mean 24 hour temperatures for 6 m and 11 m meters (T °C) were converted to MMT using a regression equation relating manually collected MMT to the temperature averaged for 6 m and 11 m for the 24 hour period coinciding with each sample date over the period April 2002-January 2004 (MMT = -3167 + 1.0075*T; r=0.98).

1. MMT 15-Oct-1998: 31.2 °C.

2. Measurement: Monthly from December 1998 to January 2004 and in June and August 2004 to present, we recorded water temperatures in OngeimÕl Tketau (OTM) at 1m intervals from 0 to 24m at two sites with hand-held YSI 85 or Hydrolab Quanta meter. The mean mixolimnion temperature (MMT) for each sample date is the average of the mean temperature for each 1m depth interval (n=2 per depth) over the depth of the mixolimnion (0-12m, n=13; defined as the depth range of the upper mixed layer over which trends in lake physical properties are congruent). Values based on an alternative definition (0-13 m) which were previously posted on this site, can be found here; differences are attributable to rounding error.

3. Updated monthly, during the middle of each month.

4. Martin, L.E., M.N Dawson, L.J. Bell, & P.L. Colin. 2005. Marine lake ecosystem dynamics illustrate ENSO variation in the tropical western Pacific. Biol. Lett. 2:144-147.

Links:

Niño 3.4 and other ENSO indices