In January 2016, a high-precipitation event (HPE) affected northwestern Ecuador, leading to devas... more In January 2016, a high-precipitation event (HPE) affected northwestern Ecuador, leading to devastating flooding in the Esmeraldas River Basin. The HPE appeared in the aftermath of the 2015/16 El Niño as an early onset of heavy rainfalls, normally expected in the peak rainy season between March and April. We investigate the local HPE atmospheric setting and the regional “weather-within-climate” characteristics of the growing-season rainfall between December and January using gauge data, satellite imagery, and reanalysis. The unusual convective environment in late January 2016 involved local and synoptic drivers leading the development of a mesoscale convective complex (MCC) during the nighttime of 24th January. The genesis of the MCC was related to an early-arriving thermal weather state and orographic lifting; the Andean ranges acted as both a channel boosting upslope flow and convective updrafts and as a heavy rain divide for inner valleys. The synoptic controls were associated wi...
Streamflow is the runoff response integrated in space and time over a complex system involving cl... more Streamflow is the runoff response integrated in space and time over a complex system involving climatic and catchment physiographic factors. In the Andes, accelerating runoff process understanding is hampered by the inability to quantify heterogeneity of surface and subsurface catchment properties. Here, we present a statistical approach based on regression models and correlation analysis that links hydrological signatures and catchment properties to unveil processes in a set of volcanic mountain catchments (latitude 0°30'N) in Ecuador. The catchments represent form and function diversity in the same hydrological unit. We found that despite of similar atmospheric‐water inputs the water yield in the north‐east region is about 5× larger than in the south‐west region and their flow regimes are asymmetric. The soil‐bedrock interface and lithology exert a first‐order control on hydrologic partitioning, and this allowed us to hypothesize two hydrological mechanisms. Firstly, in the no...
The seasonal predictability of daily rainfall characteristics is examined over 21 hydrologic unit... more The seasonal predictability of daily rainfall characteristics is examined over 21 hydrologic units in the Pacific–Andean region of Ecuador and Peru (PAEP) using a nonhomogeneous hidden Markov model (NHMM) and retrospective seasonal information from general circulation models (GCMs). First, a hidden Markov model is used to diagnose four states that play distinct roles in the December–May rainy season. The estimated daily states fall into two wet states, one dry state, and one transitional dry–wet state, and show a systematic seasonal evolution together with intraseasonal and interannual variability. The first wet state represents regionwide wet conditions, while the second one represents north–south gradients. The former could be associated with the annual moisture offshore of the PAEP, thermally driven by the climatological maximum of sea surface temperatures in the Niño-1.2 region. The latter corresponds with the dynamically noisy component of the PAEP rainfall signal, associated w...
In January 2016, a high precipitation event (HPE) affected the northern coast of Ecuador leading ... more In January 2016, a high precipitation event (HPE) affected the northern coast of Ecuador leading to devastating flooding in the Esmeraldas’ river basin. The HPE appeared in the aftermath of the 2015/2016 El Niño as an early onset of heavy rainfalls otherwise expected in the core rainy season (Mar-Apr). Using gauge data, satellite imagery and reanalysis we investigate the daily and ‘weatherwithin-climate’ characteristics of the HPE and its accompanying atmospheric conditions. The convective storms developed into a mesoscale convective complex (MCC) during nighttime on 24 th
Global characterization of streamflow patterns based on climatic and physiographic characteristic... more Global characterization of streamflow patterns based on climatic and physiographic characteristics is important for advancing understanding of large-scale hydrology, assessment of macro-scale hydrological models, and detection of global hydrological changes, among other applications. Here, based on large and open global datasets of streamflow observations, topography, landscape information, and meteorological forcing, we investigate the main controls of streamflow characteristics at global scale using a combination of data analysis techniques (Kuentz et al, 2017). First, we use streamflow records at more than 10,000 gauges to compute 15 flow signatures describing magnitude, frequency and duration of flow events, and catchment responses. We also compute indices describing upstream catchment climatic forcing and a set of 44 descriptors of physiography. Then, we perform cluster analysis using both flow and catchment characteristics to identify hydrological similarity and train tree-bas...
In January 2016, a high-precipitation event (HPE) affected northwestern Ecuador, leading to devas... more In January 2016, a high-precipitation event (HPE) affected northwestern Ecuador, leading to devastating flooding in the Esmeraldas River Basin. The HPE appeared in the aftermath of the 2015/16 El Niño as an early onset of heavy rainfalls, normally expected in the peak rainy season between March and April. We investigate the local HPE atmospheric setting and the regional “weather-within-climate” characteristics of the growing-season rainfall between December and January using gauge data, satellite imagery, and reanalysis. The unusual convective environment in late January 2016 involved local and synoptic drivers leading the development of a mesoscale convective complex (MCC) during the nighttime of 24th January. The genesis of the MCC was related to an early-arriving thermal weather state and orographic lifting; the Andean ranges acted as both a channel boosting upslope flow and convective updrafts and as a heavy rain divide for inner valleys. The synoptic controls were associated wi...
Streamflow is the runoff response integrated in space and time over a complex system involving cl... more Streamflow is the runoff response integrated in space and time over a complex system involving climatic and catchment physiographic factors. In the Andes, accelerating runoff process understanding is hampered by the inability to quantify heterogeneity of surface and subsurface catchment properties. Here, we present a statistical approach based on regression models and correlation analysis that links hydrological signatures and catchment properties to unveil processes in a set of volcanic mountain catchments (latitude 0°30'N) in Ecuador. The catchments represent form and function diversity in the same hydrological unit. We found that despite of similar atmospheric‐water inputs the water yield in the north‐east region is about 5× larger than in the south‐west region and their flow regimes are asymmetric. The soil‐bedrock interface and lithology exert a first‐order control on hydrologic partitioning, and this allowed us to hypothesize two hydrological mechanisms. Firstly, in the no...
The seasonal predictability of daily rainfall characteristics is examined over 21 hydrologic unit... more The seasonal predictability of daily rainfall characteristics is examined over 21 hydrologic units in the Pacific–Andean region of Ecuador and Peru (PAEP) using a nonhomogeneous hidden Markov model (NHMM) and retrospective seasonal information from general circulation models (GCMs). First, a hidden Markov model is used to diagnose four states that play distinct roles in the December–May rainy season. The estimated daily states fall into two wet states, one dry state, and one transitional dry–wet state, and show a systematic seasonal evolution together with intraseasonal and interannual variability. The first wet state represents regionwide wet conditions, while the second one represents north–south gradients. The former could be associated with the annual moisture offshore of the PAEP, thermally driven by the climatological maximum of sea surface temperatures in the Niño-1.2 region. The latter corresponds with the dynamically noisy component of the PAEP rainfall signal, associated w...
In January 2016, a high precipitation event (HPE) affected the northern coast of Ecuador leading ... more In January 2016, a high precipitation event (HPE) affected the northern coast of Ecuador leading to devastating flooding in the Esmeraldas’ river basin. The HPE appeared in the aftermath of the 2015/2016 El Niño as an early onset of heavy rainfalls otherwise expected in the core rainy season (Mar-Apr). Using gauge data, satellite imagery and reanalysis we investigate the daily and ‘weatherwithin-climate’ characteristics of the HPE and its accompanying atmospheric conditions. The convective storms developed into a mesoscale convective complex (MCC) during nighttime on 24 th
Global characterization of streamflow patterns based on climatic and physiographic characteristic... more Global characterization of streamflow patterns based on climatic and physiographic characteristics is important for advancing understanding of large-scale hydrology, assessment of macro-scale hydrological models, and detection of global hydrological changes, among other applications. Here, based on large and open global datasets of streamflow observations, topography, landscape information, and meteorological forcing, we investigate the main controls of streamflow characteristics at global scale using a combination of data analysis techniques (Kuentz et al, 2017). First, we use streamflow records at more than 10,000 gauges to compute 15 flow signatures describing magnitude, frequency and duration of flow events, and catchment responses. We also compute indices describing upstream catchment climatic forcing and a set of 44 descriptors of physiography. Then, we perform cluster analysis using both flow and catchment characteristics to identify hydrological similarity and train tree-bas...
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Papers by Luis Pineda