Starting in 2007, CORDIO has conducted a regional bleaching warning alert during the local ‘summer’ from January to April/May each year. The regional approach enables customization of the warnings using local to regional factors that are important in altering bleaching risk and makes the tools more accessible to non-specialist users such as agency and protected area managers.
In 2011-13 the bleaching alert was improved through a collaboration with the Kenya Meteorological Department under a grant from WIOMSA, benefiting from interactions with regional climate service organizations through the Greater Horn of Africa Climate Outlook Fora (GHACOF).
Subregional temperature structure – in 2013, ‘bleaching climatic’ regions were defined by cluster analysis of monthly SST statistics from January – May of 2003-2009 as ‘background’ years (left), and 2010 as a hot year (right). This is in contrast to the older climatological record used by NOAA based on pre-1998 conditions (1987-1993).
Based on this, five SST zones were identified, with some of these broken into sub-zones due to latitudinal extent and geographic splits:
A – the hottest region; the East Mozambique Channel and Comoros (reported as SW Madagascar-A1; and the NE Mozambique Channel-A2) and the NW Seychelles islands (A3)
B – the second hottest region; East African mainland coast from 7-18S (Zanzibar/Dar es Salaam to Primeiras/Segundas islands), and including the NW Mozambique Channel
C – a moderate/intermediate region; the South Equatorial Current region, comprising the Mascarene Banks, southern Seychelles islands and NE Madagascar
E – a cooler northern but highly variable region; the Kenya-Somali coast, including Pemba island and N Tanzania coast (Tanga).