@article{fdi:010077861,
  title = {{R}ecent changes in the precipitation-driving processes over the southern tropical {A}ndes/western {A}mazon},
  author = {{S}egura, {H}. and {E}spinoza, {J}. {C}. and {J}unquas, {C}l{\'e}mentine and {L}ebel, {T}hierry and {V}uille, {M}. and {G}arreaud, {R}.},
  editor = {},
  language = {{ENG}},
  abstract = {{A}nalyzing {D}ecember-{F}ebruary ({DJF}) precipitation in the southern tropical {A}ndes-{STA} (12 circle {S}}; > 3000 m.a.s.l) allows revisiting regional atmospheric circulation features accounting for its interannual variability over the past 35 years (1982-2018). {I}n a region where in-situ rainfall stations are sparse, the {CHIRPS} precipitation product is used to identify the first mode of interannual {DJF} precipitation variability ({PC}1-{A}ndes). {A} network of 98 rain-gauge stations further allows verifying that {PC}1-{A}ndes properly represents the spatio-temporal rainfall distribution over the region; in particular a significant increase in {DJF} precipitation over the period of study is evident in both in-situ data and {PC}1-{A}ndes. {U}sing the {ERA}-{I}nterim data set, we found that aside from the well-known relationship between precipitation and upper-level easterlies over the {STA}, {PC}1-{A}ndes is also associated with upward motion over the western {A}mazon ({WA}), a link that has not been reported before. {T}he ascent over the {WA} is a component of the meridional circulation between the tropical {N}orth {A}tlantic and western tropical {S}outh {A}merica-{WTSA} (80 circle {W}). {I}ndeed, the precipitation increase over the last 2 decades is concomitant with the strengthening of this meridional circulation. {A}n intensified upward motion over the {WA} has moistened the mid-troposphere over {WTSA}, and as a consequence, a decreased atmospheric stability between the mid- and the upper troposphere is observed over this region, including the {STA}. {W}e further show that, over the last 15 years or so, the year-to-year variability of {STA} precipitation (periodicity < 8 years) has been significantly associated with upward motion over the {WA}, while upper-level easterlies are no longer significantly correlated with precipitation. {T}hese observations suggests that the {STA} have experienced a transition from a dry to a wet state in association with a change in the dominant mode of atmospheric circulation. {I}n the former dominant state, zonal advection of momentum and moisture from the central {A}mazon, associated with upper-level easterlies, is necessary to develop convection over the {STA}. {S}ince the beginning of the 21st century, {DJF} precipitation over the {STA} seems to respond directly and primarily to upward motion over the {WA}. {B}eyond improving our understanding of the factors influencing {STA} precipitation nowadays, these results point to the need of exploring their possible implications for the long-term evolution of precipitation in a context of global warming.},
  keywords = {{A}mazon-{A}ndes connectivity ; {A}ltiplano precipitation ; {A}mazon convection ; {S}outh {A}merica atmospheric circulation ; {AMERIQUE} {DU} {SUD} ; {PEROU} ; {BOLIVIE} ; {ANDES} ; {AMAZONIE} ; {ZONE} {TROPICALE} ; {ATLANTIQUE} ; {PACIFIQUE} ; {ALTIPLANO}},
  booktitle = {},
  journal = {{C}limate {D}ynamics},
  volume = {54},
  numero = {5-6},
  pages = {2613--2631},
  ISSN = {0930-7575},
  year = {2020},
  DOI = {10.1007/s00382-020-05132-6},
  URL = {https://www.documentation.ird.fr/hor/fdi:010077861},
}