March 2022 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.
The sea surface temperature anomalies (SSTAs) across the central and eastern equatorial Pacific were still below average (-0.5ºC to -1.5ºC) during the month, conversely, the western Pacific near the Maritime continent was observed to be near to warmer than average (0°C to 1.0°C).
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.
Neutral IOD value was observed in March, as SSTs in the western equatorial Indian Ocean were slightly cooler than the eastern equatorial Indian Ocean.
