February 2021 Sea Surface Temperature Assessment
A. Niño Regions
Niño SST Indices are based on the average of SST anomalies across the given regions: Niño 1+2 (0-10S, 90W-80W), Niño 3 (5N-5S, 150W-90W), Niño 3.4 (5N-5S, 170W-120W) and Niño 4 (5N-5S, 160E-150W). These indices are used to monitor the conditions in the Tropical Pacific for the occurrence of El Niño or La Niña events.
For the month of February, below average sea surface temperature anomalies (SSTAs) of ~ -0.5 to -1.5°C continue to persist in the tropical Pacific. However in the western Pacific near the Maritime continent, SSTAs were near to warmer than average with 0.5°C to 2.0 °C anomaly located east of the Philippines, while on the western side, near to slightly below average SSTAs were observed.
B. Indian Ocean Dipole (IOD)
The Indian Ocean Dipole mode Index (DMI) is defined as the difference between the SST anomalies (ºC) of Western (10ºS-10ºN & 50ºE-70ºE) and Eastern (10ºS-0ºN & 90ºE-110ºE) Equatorial Indian Ocean regions (WEST-EAST). The DMI values represent the intensity of the Indian Ocean Dipole (IOD); DMI values above +0.4 °C is referred as the positive IOD, DMI values below −0.4 °C is referred as the negative IOD and DMI values between +0.4 °C and -0.4 °C is referred as the neutral IOD.
The IOD value for February was slightly negative but still within neutral level as SSTAs across most of the equatorial Indian Ocean were observed to be near to slightly cooler than average.
