Читать книгу Congo Basin Hydrology, Climate, and Biogeochemistry - Группа авторов - Страница 48

One of the very unusual characteristics of the rainfall regime over the Congo is the extremely low spatial variability. Elsewhere in Africa rainfall variability on interannual time scales is coherent over large areas. Over the Congo, variability is localized and the correlation between individual stations is exceedingly low in both rainy seasons.

Because of the paucity of gauge data in the Congo Basin, it is difficult to provide a detailed and reliable picture of the interannual variability of rainfall. Six sectors were examined, three of which fall largely within the Congo Basin. In most of the regions a shift to drier conditions occurred around 1970. It was apparent in MAM in all areas but the central Congo Basin, in annual rainfall in the northern and southern basin, and in ON rainfall over the northern basin and in Cameroon. This was roughly synchronous with the major decline in Sahel rainfall c. 1968 that was evident in all months between April and November (Nicholson et al., 2018b, c). Abrupt changes occurred in the rainfall regime along the Guinea Coast as well around the same time. The changes observed in those regions and in the Congo Basin appear to be associated with a quasi‐global change in teleconnections to the global oceans.