Nonlinear interactions between the Amazon River basin and the Tropical North Atlantic at interannual timescales

Builes‐Jaramillo, Alejandro; Marwan, Norbert; Poveda, Germán; Kurths, Jürgen

doi:10.1007/s00382-017-3785-8

Cited by 40 publications

(22 citation statements)

References 71 publications

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“…On the other hand, the process variables (PRC and EVP) are the most complex in the region HPREC= 0.76 and HEVP= 0.71. This result confirms the diversity of factors that make part of the hydro-climatic variance at interannual timescale, thus reflecting the implicit complexity of the linkages between these two processes over TropSA [44,46,59,[70][71][72]. The high entropy of EVP can be also explained in terms of the multivariate influence of water and energy fluxes in TropSA [22,47,73].…”

Section: Svd Noise Reduction and Entropysupporting

confidence: 71%

<strong>New insights on land surface-atmosphere feedbacks over tropical South America at interannual timescales</strong>

Bedoya-Soto

Poveda

2017

Proceedings of First International Electronic Conference on the Hydrological Cycle

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Abstract:Using monthly data for the period 1979-2010, we study the dynamics and strength of land surface-atmosphere feedbacks (LAFs) among variables involved in the heat and moisture fluxes, at interannual timescales in Tropical South America (TropSA). The variables include precipitation, surface air temperature, specific humidity at 925 hPa, evaporation, and estimates of volumetric soil water content. We use a Maximum Covariance Analysis (MCA) to reduce the dimensionality and to rank the relative contributions to LAFs and group the time series into Maximum Covariance States (MCS) with common mechanisms among variables. We estimate linear (Pearson correlations) and non-linear association (information transfer or causality) metrics among pairs of variables to configure the structure of linkages. The main MCS associated with LAFs over TropSA are strongly influenced by ENSO, and the meridional and equatorial SSTs modes over the Atlantic and Indian Oceans. ENSO favors a unimodal behavior, with center of action in the Amazon River basin, while the SSTs mode over the Tropical North Atlantic (TNA) results in a dipole between northern and southern TropSA. Our results show that soil moisture plays a leading role in regulating heat and water anomalies, and provides the memory of the LAFs and their subsequent influence. Thus, volumetric soil water becomes a fundamental variable leading up to 9 month-lags. ENSO enhances the interannual connectivity and memory inside LAF mechanisms with respect to other modes. Within the identified multivariate structure, evaporation and soil moisture enhance the interannual connectivity of the whole set of variables since both variables exhibit more frequent two-way feedbacks with the remaining variables.

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Section: Svd Noise Reduction and Entropysupporting

confidence: 71%

<strong>New insights on land surface-atmosphere feedbacks over tropical South America at interannual timescales</strong>

Bedoya-Soto

Poveda

2017

Proceedings of First International Electronic Conference on the Hydrological Cycle

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“…The results reported by Marengo () indicate lower imbalances in the Amazon River basin during La Niña years, which may imply that convergence is overestimated in episodes of higher than normal precipitation during the dry season, with a surplus of available atmospheric moisture. The previous results indicates that the hydrological cycle in the basin may be altered during extreme events, such as the ones induced by the perturbations of the walker circulation over the Amazon during ENSO episodes; anomalous high temperatures on the TNA related with the increase of moisture transport towards the basin; floodings related with the influence of La Niña events, Tropical South Atlantic and Indo‐Pacific SST's anomalies (Builes‐Jaramillo et al, ; Cavalcanti et al, ; Espinoza et al, ; Marengo & Espinoza, ; Molina‐Carpio et al, ); or even the increased convergence over the south basin induced by the South American Convergence Zone during the austral summer (de Oliveira Vieira et al, ). Thus, one can assume that shortcomings exist regarding the representation of the water balance that may be influenced by the modeling of terms such as precipitable water or the poor representation of evapotranspiration (Guiana et al, ; Jasechko et al, ), potentially leading to the underestimation of evapotranspiration in the basin.…”

Section: Resultsmentioning

confidence: 96%

Conjoint Analysis of Surface and Atmospheric Water Balances in the Andes‐Amazon System

Builes‐Jaramillo

Poveda

2018

Water Resources Research

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Surface and atmospheric water balances analysis for Amazon River basin at monthly time scale are performed with an emphasis on the linkages between the Andes and low-lying Amazonia. Analyses are performed using observational and reanalysis data covering five different periods of analysis (depending on length of evapotranspiration data sets) for the entire basin, major subcatchments, and for the Andes and low-lying Amazonia. Results for the entire basin show a state close to balance within tolerance, while the spatial disaggregation produced a less clear picture, presenting major discrepancies between observations and reanalysis data sets. The atmospheric budget exhibits no closure and positive residuals regardless of data set, with the magnitude of residuals for the entire Amazon basin highly dependent on evapotranspiration data source. The imbalance between the two water budgets (14%-16%) is driven by higher values of runoff and by an abrupt change in runoff when changing from dry to wet seasons in the Amazon. We unveil two shortcomings of the available data, namely poor quality in the representation of surface processes by reanalysis, and flaws and scarcity of information in the high Andes that induce uncertainties and errors in both water budgets. The results of the present study highlight the importance of the Andean region for the hydrological integrity of the entire Amazon River basin. Our results confirm the paramount importance of the joint analysis of atmospheric and surface water budgets at the basin level with respect to achieving a complete understanding of the whole hydrological cycle at the continental scale.

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“…The Budyko approach was used to verify the water and energy limit of for evapotranspiration. The Budyko hypothesis (Budyko, 1974) says that long-term evapotranspiration is determined by available water (P) and available energy measured by potential evapotranspiration (PET) and can be analysed by the relationship between the aridity index (PET/P) and the evaporative index (ET/P). However, for shorter timescales, water storage should be considered to properly represent the partition of the precipitation between the ET and Q (Zhang et al, 2008;Wang et al, 2009).…”

Section: Monthly Water Balancementioning

confidence: 99%

“…ENSO and NATL influence extreme climatic events over Amazonia (Zeng et al, 2008;Marengo et al, 2011;Jiménez-Muñoz et al, 2016) and more than half of the variance in Amazon precipitation can be predicted based on them (Zeng et al, 2008). However, their combined influence is complex, due to the differences in peak time and Amazon region affected (Zeng et al, 2008), and is further complicated by the partial influence of ENSO on the NATL (Giannini et al, 2001;Yoon and Zeng, 2010;Builes-Jaramillo et al, 2018).…”

Section: Introductionmentioning

confidence: 99%

Terrestrial water storage and Pacific SST affect the monthly water balance of Itacaiúnas River Basin (Eastern Amazonia)

Cavalcante

Pontes

Tedeschi

et al. 2019

Intl Journal of Climatology

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At subannual timescales, terrestrial water storage (TWS) plays a critical role in the partitioning of precipitation into runoff and evapotranspiration, and Amazonia stands out due to the great amplitude of the annual cycles. In this study, we analyse the monthly variation of the water balance and extreme hydrological events using GRACE data for a watershed situated in the "arc-ofdeforestation" in the Eastern Brazilian Legal Amazon. The existence of a correlation and lag time response between the monthly sea surface temperatures in the Pacific and North Atlantic and the variables of the water balance were also investigated. The results showed a weak seasonal cycle of evapotranspiration, with higher water intercepted by the vegetation canopy in the rainy season and higher potential evapotranspiration supplied by TWS in the dry season. The lowest value of water storage was reached in

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Nonlinear interactions between the Amazon River basin and the Tropical North Atlantic at interannual timescales

Cited by 40 publications

References 71 publications

<strong>New insights on land surface-atmosphere feedbacks over tropical South America at interannual timescales</strong>

<strong>New insights on land surface-atmosphere feedbacks over tropical South America at interannual timescales</strong>

Conjoint Analysis of Surface and Atmospheric Water Balances in the Andes‐Amazon System

Terrestrial water storage and Pacific SST affect the monthly water balance of Itacaiúnas River Basin (Eastern Amazonia)

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