Intra‐seasonal rainfall variability in the Amazon basin related to large‐scale circulation patterns: a focus on western Amazon–Andes transition region

This study aims to relate the intra-seasonal rainfall variability over the Amazon basin to atmospheric circulation patterns (CPs), with particular attention to extreme rainfall events in the Amazon–Andes region. The CPs summarize the intra-seasonal variability of atmospheric circulation and are defined using daily low-level winds from the ERA-Interim (1.5° × 1.5°) reanalysis for the 1979–2014 period. Furthermore, observational data of precipitation and high-resolution TRMM 3B42 (∼25 km), 2A25 PR (∼5 km) and CHIRPS (∼5 km) data products are related to the CPs throughout the Amazon basin. Nine CPs are determined using a hybrid method that combines a neural network technique (self-organizing maps, SOM) and hierarchical ascendant classification. The CPs are characterized by a specific cycle with alternative transitions and a duration of 14 days on average. This configuration initially results in northerly winds to southerly winds towards the northern or eastern Amazon basin. The related rainfall suggests that it is driven mainly by CP dynamics. In addition, we demonstrate a good agreement amongst the four rainfall data sets: observed precipitation, TRMM 3B42, TRMM 2A25 PR and CHIRPS. Furthermore, special attention is given to the Amazon–Andes transition region. Over this region, two particular CPs (CP4 and CP5) are identified as the key contributors of maximum and minimum daily rainfall, respectively. Thus, during the dry season, 40.8% (11.4%) of the CP5 (CP4) days demonstrate rainfall of less than 1 mm day −1 , while during the wet season, 6.2% (14.6%) of the CP5 (CP4) days show rainfall amounts higher than the seasonal 90th percentile (10.4 mm day −1 ). This study provides additional information concerning the intra-seasonal circulation variability in Amazonia and demonstrates the value of using remote sensing precipitation data in this region as a tool for forecast in areas lacking observable information.

[1]  S. Thiria,et al.  Weather regimes over Senegal during the summer monsoon season using self-organizing maps and hierarchical ascendant classification. Part I: synoptic time scale , 2011 .

[2]  A. Getirana,et al.  Assessment of different precipitation datasets and their impacts on the water balance of the Negro River basin , 2011 .

[3]  C. Jones,et al.  The South Atlantic Convergence Zone: Intensity, Form, Persistence, and Relationships with Intraseasonal to Interannual Activity and Extreme Rainfall , 2004 .

[4]  I. Orlanski.  A rational subdivision of scales for atmospheric processes , 1975 .

[5]  David J. Knight,et al.  South American Cold Surges: Types, Composites, and Case Studies , 2001 .

[6]  C. Saulo,et al.  Subseasonal Variations of Rainfall in South America in the Vicinity of the Low-Level Jet East of the Andes and Comparison to Those in the South Atlantic Convergence Zone , 2004 .

[7]  C. Prigent,et al.  Discharge simulation in the sub-basins of the Amazon using ORCHIDEE forced by new datasets , 2011 .

[8]  K. Mo,et al.  Alternating Wet and Dry Conditions over South America during Summer , 1997 .

[9]  Christian Onof,et al.  A Comparative Performance Analysis of TRMM 3B42 (TMPA) Versions 6 and 7 for Hydrological Applications over Andean–Amazon River Basins , 2014 .

[10]  J. Marengo,et al.  Extreme seasonal droughts and floods in Amazonia: causes, trends and impacts , 2015 .

[11]  L. Verchot,et al.  Decadal covariability of Atlantic SSTs and western Amazon dry‐season hydroclimate in observations and CMIP5 simulations , 2015 .

[12]  Y. Hong,et al.  The TRMM Multisatellite Precipitation Analysis (TMPA): Quasi-Global, Multiyear, Combined-Sensor Precipitation Estimates at Fine Scales , 2007 .

[13]  Maisa Rojas,et al.  A correlated shortening of the North and South American monsoon seasons in the past few decades , 2015, Climate Dynamics.

[14]  Edward J. Zipser,et al.  THE SOUTH AMERICAN LOW-LEVEL JET EXPERIMENT , 2006 .

[15]  R. Mittermeier,et al.  Biodiversity hotspots for conservation priorities , 2000, Nature.

[16]  K. Okamoto,et al.  Rain profiling algorithm for the TRMM precipitation radar , 1997, IGARSS'97. 1997 IEEE International Geoscience and Remote Sensing Symposium Proceedings. Remote Sensing - A Scientific Vision for Sustainable Development.

[17]  H. Wheater,et al.  Evaluation of precipitation products over complex mountainous terrain: A water resources perspective , 2011 .

[18]  A. Getirana,et al.  Impacts of satellite-based precipitation datasets on rainfall–runoff modeling of the Western Amazon basin of Peru and Ecuador , 2015 .

[19]  Josyane Ronchail,et al.  Rainfall hotspots over the southern tropical Andes: Spatial distribution, rainfall intensity, and relations with large‐scale atmospheric circulation , 2015 .

[20]  Charles Jones,et al.  Extreme Precipitation Events in Southeastern South America and Large-Scale Convective Patterns in the South Atlantic Convergence Zone , 2002 .

[21]  George N. Kiladis,et al.  Submonthly Convective Variability over South America and the South Atlantic Convergence Zone , 1999 .

[22]  Thomas Condom,et al.  Correction of TRMM 3B43 monthly precipitation data over the mountainous areas of Peru during the period 1998–2007 , 2011 .

[23]  R. Fu,et al.  Cross-Equatorial Flow and Seasonal Cycle of Precipitation over South America , 2002 .

[24]  Josyane Ronchail,et al.  Evolution of wet‐day and dry‐day frequency in the western Amazon basin: Relationship with atmospheric circulation and impacts on vegetation , 2016 .

[25]  C. Menéndez,et al.  Weather regimes in the South American sector and neighbouring oceans during winter , 2003 .

[26]  J. Espinoza.  Impact de la variabilité climatique sur l'hydrologie du bassin amazonien , 2009 .

[27]  Yann L'hote,et al.  Evolution du débit de l’Amazone à Óbidos de 1903 à 1999 / Evolution of the River Amazon’s discharge at Óbidos from 1903 to 1999 , 2004 .

[28]  C. Nobre,et al.  Cold Surges in Tropical and Extratropical South America: The Strong Event in June 1994 , 1997 .

[29]  Andrew W. Robertson,et al.  Weather Types and Rainfall over Senegal. Part I: Observational Analysis , 2008 .

[30]  Augusto Getirana,et al.  Hydrological modeling of the Peruvian-Ecuadorian Amazon basin using GPM-IMERG satellite-based precipitation dataset. , 2016, Hydrology and earth system sciences.

[31]  J. Marengo,et al.  Tropical-midlatitude exchange of air masses during summer and winter in South America: climatic aspects and examples of intense events , 2000 .

[32]  M. Lengaigne,et al.  Large-scale circulation patterns and related rainfall in the Amazon Basin: a neuronal networks approach , 2011, Climate Dynamics.

[33]  J. H. Ward.  Hierarchical Grouping to Optimize an Objective Function , 1963 .

[34]  J. Michaelsen,et al.  The climate hazards infrared precipitation with stations—a new environmental record for monitoring extremes , 2015, Scientific Data.

[35]  George J. Huffman,et al.  Evaluation of TRMM Multi-satellite Precipitation Analysis (TMPA) performance in the Central Andes region and its dependency on spatial and temporal resolution , 2010 .

[36]  J. Thepaut,et al.  The ERA‐Interim reanalysis: configuration and performance of the data assimilation system , 2011 .

[37]  T. Killeen,et al.  Dry spots and wet spots in the Andean hotspot , 2007 .

[38]  Matthieu Lengaigne,et al.  Twentieth century ENSO characteristics in the IPCC database , 2008 .

[39]  Celeste Saulo,et al.  Climatology of the Low-Level Jet East of the Andes as Derived from the NCEP–NCAR Reanalyses: Characteristics and Temporal Variability , 2004 .

[40]  R. Paiva,et al.  Large scale hydrologic and hydrodynamic modeling using limited data and a GIS based approach , 2011 .

[41]  J. Ronchail,et al.  Spatio‐temporal rainfall variability in the Amazon basin countries (Brazil, Peru, Bolivia, Colombia, and Ecuador) , 2009 .

[42]  H. Lettau,et al.  Amazonia's Hydrologic Cycle and the Role of Atmospheric Recycling in Assessing Deforestation Effects , 1979 .

[43]  M. Lengaigne,et al.  Revisiting wintertime cold air intrusions at the east of the Andes: propagating features from subtropical Argentina to Peruvian Amazon and relationship with large-scale circulation patterns , 2012, Climate Dynamics.

[44]  R. Dickinson,et al.  How Do Tropical Sea Surface Temperatures Influence the Seasonal Distribution of Precipitation in the Equatorial Amazon , 2001 .

[45]  Robin T. Clarke,et al.  A comparison of Amazon rainfall characteristics derived from TRMM, CMORPH and the Brazilian national rain gauge network , 2011 .

[46]  Josyane Ronchail,et al.  The extreme 2014 flood in south-western Amazon basin: the role of tropical-subtropical South Atlantic SST gradient , 2014 .

[47]  J. Espinoza,et al.  Radiative properties of clouds over a tropical Bolivian glacier: seasonal variations and relationship with regional atmospheric circulation , 2016 .

[48]  Dennis P. Lettenmaier,et al.  Toward a unified view of the American monsoon systems , 2006 .

[49]  R. Garreaud,et al.  Cold Air Incursions over Subtropical South America: Mean Structure and Dynamics , 2000 .

[50]  J. Ronchail,et al.  Heterogeneous Distribution of Rainfall and Discharge Regimes in the Ecuadorian Amazon Basin , 2007 .

[51]  A. Anders,et al.  Very high resolution precipitation climatologies from the Tropical Rainfall Measuring Mission precipitation radar , 2009 .

[52]  P. Lucio,et al.  Synoptic patterns of atmospheric circulation associated with intense precipitation events over the Brazilian Amazon , 2017, Theoretical and Applied Climatology.