233
cant impacts on the economy of the developing and poor countries. There is
also interest in the future behavior of the climate variability in a world submitted to the effects of global warming. For several years, the Pacific has been
considered as the most important tropical and extratropical climate regulator
at different time scales and mainly during the El Nino Southern Oscillation
(ENSO) phenomenon. Effectively, this phenomenon produces extreme events
(inundations, droughts) at the scale of the Pacific Basin but also at the global
level through complex teleconnections systems (Ropelewski and Halpert
1989). For these reasons and during many years, the interest and efforts of the
scientific community have been focused on the study of the Pacific Ocean and
its variability to the detriment of the Atlantic Ocean. From the 2000s, scientific studies conducted by international teams have shown that the Atlantic
Ocean also modulated the climate (Knight et al. 2005). But in reality, the climate in the tropics is the result of the integration of these main mechanisms
(including Monsoon systems) whose duration and specific amplitude can balance, dilute, or favor the expression of their actions on tropical systems.
8
Recent studies on the role of decadal and multidecadal variability in the
Atlantic Ocean have shown that these modes of multidecadal variability
(AMO-Atlantic Multidecadal Oscillation, and NAO-North Atlantic
Oscillation) may lead to drought in Mexico, Brazil, and Morocco but with
very heterogeneous and antiphase expressions (Méndez and Magaña 2010).
For example, a positive mode of AMO causes droughts in Amazon region
(Marengo et al. 2011), Northern Mexico (M), and inundations in Southern
Morocco. The heterogeneity of spatial and temporal expressions of these
transatlantic events, the associated impacts, and the underlying mechanisms
remain poorly understood. Therefore, it is of seminal importance to establish
the long-term (past, present, and future) climate variability envelope within
the framework of the Agadir Platform encouraging transatlantic cooperation
and research activities on both sides of the Atlantic in Latin America and in
North and West Africa, and on the role of the Atlantic and its impacts on dryland continental and coastal marine ecosystems. Within the framework of a
transatlantic collaboration effort among Brazilian, French, Mexican, and
Moroccan scientists, spearheaded by RISZA and the CHARISMA
9
project,
preliminary results of the analysis of instrumental data during the last century
confirm those trends (increase in temperature and decrease in precipitations)
in Mexico, South America, and Morocco.
8 It concerns also the Atlantic and Pacific variabilities from the interannual to millennium time
scales.
9
CHAngement et vaRIabilitéS cliMAtiques passés et actuelles au Maroc: forçages, réponses,
impacts et rétroactions—Bases pour la proposition de solutions d’adaptations (Past and current
climate change and variability in Morocco: forcing, responses, impacts, and feedback—Basis for
proposing adaptation solutions).
14 The Agadir Platform: A Transatlantic Cooperation to Achieve Sustainable Drylands
cant impacts on the economy of the developing and poor countries. There is
also interest in the future behavior of the climate variability in a world submitted to the effects of global warming. For several years, the Pacific has been
considered as the most important tropical and extratropical climate regulator
at different time scales and mainly during the El Nino Southern Oscillation
(ENSO) phenomenon. Effectively, this phenomenon produces extreme events
(inundations, droughts) at the scale of the Pacific Basin but also at the global
level through complex teleconnections systems (Ropelewski and Halpert
1989). For these reasons and during many years, the interest and efforts of the
scientific community have been focused on the study of the Pacific Ocean and
its variability to the detriment of the Atlantic Ocean. From the 2000s, scientific studies conducted by international teams have shown that the Atlantic
Ocean also modulated the climate (Knight et al. 2005). But in reality, the climate in the tropics is the result of the integration of these main mechanisms
(including Monsoon systems) whose duration and specific amplitude can balance, dilute, or favor the expression of their actions on tropical systems.
8
Recent studies on the role of decadal and multidecadal variability in the
Atlantic Ocean have shown that these modes of multidecadal variability
(AMO-Atlantic Multidecadal Oscillation, and NAO-North Atlantic
Oscillation) may lead to drought in Mexico, Brazil, and Morocco but with
very heterogeneous and antiphase expressions (Méndez and Magaña 2010).
For example, a positive mode of AMO causes droughts in Amazon region
(Marengo et al. 2011), Northern Mexico (M), and inundations in Southern
Morocco. The heterogeneity of spatial and temporal expressions of these
transatlantic events, the associated impacts, and the underlying mechanisms
remain poorly understood. Therefore, it is of seminal importance to establish
the long-term (past, present, and future) climate variability envelope within
the framework of the Agadir Platform encouraging transatlantic cooperation
and research activities on both sides of the Atlantic in Latin America and in
North and West Africa, and on the role of the Atlantic and its impacts on dryland continental and coastal marine ecosystems. Within the framework of a
transatlantic collaboration effort among Brazilian, French, Mexican, and
Moroccan scientists, spearheaded by RISZA and the CHARISMA
9
project,
preliminary results of the analysis of instrumental data during the last century
confirm those trends (increase in temperature and decrease in precipitations)
in Mexico, South America, and Morocco.
8 It concerns also the Atlantic and Pacific variabilities from the interannual to millennium time
scales.
9
CHAngement et vaRIabilitéS cliMAtiques passés et actuelles au Maroc: forçages, réponses,
impacts et rétroactions—Bases pour la proposition de solutions d’adaptations (Past and current
climate change and variability in Morocco: forcing, responses, impacts, and feedback—Basis for
proposing adaptation solutions).
14 The Agadir Platform: A Transatlantic Cooperation to Achieve Sustainable Drylands