chapter - Atmospheric and Oceanic Science

Regional climatic scenarios
13.4.3. Hadley Centre and ECHAM GCM
Results from two other models (see table 12.1 for model details), for the
southern hemisphere winter and summer seasons and different periods are presented
in figure 13.14. This figure shows the ECHAM4 and HadCM3 model simulations
for the A2 scenarios averaged for the periods 2050 and 2080 and for the
December-January-February (DJF) and June-July-August (JJA) periods. The
ECHAM4 results indicate that independently of the period (Figs. 13.14a and
13.14c), the precipitation patterns during the austral Summer show a positive
anomaly over the Southeast South America and negative ones over the Northeast
Brazil. During the Winter (Figs. 13.14b and 13.14d), the negative anomalies seem
to move towards the North of South America, while the excess of rainfall is confined
to the South of Brazil. The HadCM3 model shows similar characteristics but
with some important differences. For the austral summer, there is a noticeable
change in the precipitation anomaly amplitudes between 2050 and 2080, being
much larger in the last one (Figs. 13.14e and 13.14g). It is worthy noting that the
maximum values occur around the SACZ, which is to the North of the ECHAM4
results. Large amplitudes of negative precipitation anomalies over the North of
South America are observed during the winter (Figs. 13.14f and 13.14h). Again, the
values are much stronger for the 2080 period (Fig. 13.14h), and positive anomaly
values are basically observed in the South of South America.
13.5. Future plans of CPTEC/INPE in climate change modelling
Different improvements are currently been planned at CPTEC concerning climate
change experiments. Some of them are related to the integrations of CPTEC
models, and others will use dataset provided by other centres. CPTEC/COLA
AGCM will be integrated to simulate the future climate, considering the increase of
CO2 and also simulating the past climate considering the observed CO2 variation.
Aspects of atmospheric and land components of the hydrological cycle over the La
Plata basin will be analysed in the model results comparing the past and future climate.
Experiments considering gradual Amazonia deforestation are also been
planned with the global model. Aerosol increase and a chemical module that can
consider the carbon cycle is a need for future implementations. In this module is
expected the inclusion of other greenhouse gases as CH4 and N2O. Improvements
in convection and radiation parameterization schemes of the CPTEC/COLA model
are in progress, as well as the inclusion of a new vegetation field and soil moisture
provided by a hydrological model.
Climate change simulations planned at CPTEC will be the integration of the
regional Eta model to do a downscaling, taking as lateral boundary conditions
results of a simulation with the Hadley Centre Coupled GCM for the year 2070 to
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