E2 pH Southern Basin, 1976 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Surfac 7.2 7.2 - - 7.5 7.5 - 7.7 - 7.7 - 7.9 Source: Carmouze, J.-P., Chantraine, J. M. & Lemoalle, J. (1983) Physical and chemical characteristics of the waters. "Lake Chad" (ed. Carmouze, J.-P., Durand, J.-R. & Leveque, C.), pp. 65-94.