Research
Climate change in southern Africa
Northern Mozambique (Region 13)
22 August 2007
Long-term fluctuations
This region is also amongst the wettest parts of southern Africa and
has an opposite response to ENSO forcing than regions further
south. It borders the Indian Ocean. Partly related to its different response to
ENSO/Indian Ocean forcing is an out-of-phase low-frequency pattern of oscillation
with most of southern Africa, readily apparent in the time series plot.
The
models project weak multi-decadal oscillations
during the early part of the 21st century, but an upward precipitation trend after the turn of the century.
Region 13 precipitation differences from the 1901-1950 mean [σ] with a ten-year running mean in the observations (black bars) and
selected climate models. The blue line shows the multi-model ensemble mean. The darker (lighter) shading show 1σ (2σ) from the mean.
Annual cycle
The observed annual cycle for this region
shows that the area experiences a shorter rainfall season than the rest of
southern Africa.
The rainfall amounts exceed 6mm/day during the peak of the season.
It is
noteworthy that in almost all the models, November becomes
drier. In December there is less consensus amongst the models.
From January to March, most of the models give indications for an increase in mean monthly precipitation. The HadGEM1 and GFDL CM20 are the only notable outliers. An earlier cessation is implied by the reduction in mean monthly precipitation simulated by a large fraction of the models from April. Despite that this area is projected to become less dry, a contraction of the rainy season seems likely.
Region 13 annual cycle. The observations are shown by bars.
Model simulated annual cycle is shown by the dotted line (open diamond) for the 20th century (around 2100). For each model, the line segment displays the simulated deviation (from its 20th century) in mean monthly rainfall. Positive (negative) deviations are indicated by line segments pointing upwards (downwards) from the dotted line.
|
|
