@article{fernandes_young_2024, title={Landcover-categorized fires respond distinctly to precipitation anomalies in the South-Central United States}, volume={12}, ISSN={["2296-665X"]}, DOI={10.3389/fenvs.2024.1433920}, abstractNote={Satellite detection of active fires has contributed to advance our understanding of fire ecology, fire and climate dynamics, fire emissions, and how to better manage the use of fires as a tool. In this study, we use active fire data of 12 years (2012–2023) combined with landcover information in the South-Central United States to derive a monthly, open-access dataset of categorized fires. This is done by calculating a fire predominance index used to rank fire-prone landcovers, which are then grouped into four main landscapes: grassland, forest, wildland, and crop fires. County-level aggregated analyses reveal spatial distributions, climatologies, and peak fire months that are particular to each fire type. Using the Standardized Precipitation Index (SPI), it was found that during the climatological fire peak-month, the SPI and fires exhibit an inverse relationship in forests and crops, whereas grassland and wildland fires show less consistent inverse or even direct relationship with the SPI. This varied behavior is discussed in the context of landscapes’ responses to anomalies in precipitation and fire management practices, such as prescribed fires and crop residue burning. In a case study of Osage County (OK), we find that large wildfires, known to be closely related to climate anomalies, occur where forest fires are located in the county and absent in areas of grassland fires. Weaker grassland fire response to precipitation anomalies can be attributed to the use of prescribed burning, which is normally planned under environmental conditions that facilitate control and thus avoided during droughts. Crop fires, on the other hand, are set to efficiently burn residue and are practiced more intensely in drier years than in wetter years, explaining the consistently strong inverse correlation between fires and precipitation anomalies. In our increasingly volatile climate, understanding how fires, vegetation, and precipitation interact has become imperative to prevent hazardous fire conflagrations and to better manage ecosystems.}, journal={FRONTIERS IN ENVIRONMENTAL SCIENCE}, author={Fernandes, Katia and Young, Sean G.}, year={2024}, month={Aug} }
 @article{fernandes_bell_muñoz_2023, title={Subseasonal fire forecast in the Amazon using week-2 precipitation forecast combined with a vegetation health indicator}, url={https://doi.org/10.5194/egusphere-egu23-2085}, DOI={10.5194/egusphere-egu23-2085}, abstractNote={Numerical predictions for a lead time of 2 to 4 weeks, a timescale known as subseasonal, has only in recent years begun transitioning from research to operational settings. One experiment dedicated to that effort is the Subseasonal Experiment (SubX). In here, SubX multi-model ensemble (MME) mean precipitation forecast (2017-2021) for days 8 to 14 (week-2 forecast) is used as a covariate in logistic regression models to predict fire risk in the Amazon. The hybrid (dynamical and statistical) modelling approach describes the NextGen methodology aimed at improving forecast outcomes at the seasonal and subseasonal time scales. In a complementary experiment, a vegetation health index (VHI) is added to SubX precipitation forecasts as a predictor to fires. The findings show that fire risk can be skillfully assessed in most of the Amazon where fires occur regularly. In some sectors, SubX week-2 precipitation alone is a reliable predictor of fire risk, but the addition of VHI results both in (i) a larger portion of the Amazon domain with skillful forecasts and; (ii) higher skill in some sectors. The added information provided by VHI as a predictor is most relevant where the mosaic of land covers includes savannas and grassland, whereas SubX precipitation can be used as the sole predictor for week-2 fire risk forecast where the mosaic of land cover is dominated by forests. The operationalization of the methods presented in this study could allow for better preparedness and fire risk reduction in the Amazon with a lead time greater than a week.}, author={Fernandes, Katia and Bell, Michael and Muñoz, Ángel}, year={2023}, month={May} }
 @article{fernandes_bell_muñoz_2022, title={Combining precipitation forecasts and vegetation health to predict fire risk at subseasonal timescale in the Amazon}, volume={17}, url={https://doi.org/10.1088/1748-9326/ac76d8}, DOI={10.1088/1748-9326/ac76d8}, abstractNote={Abstract
               Current forecast systems provide reliable deterministic forecasts at the scale of weather (1–7 days) and probabilistic outcomes at the scale of seasons (1–9 months). Only in recent years research has begun transitioning to operational settings to provide numerical predictions for a lead time of 2–4 weeks, a timescale known as subseasonal. The Subseasonal Experiment (SubX) multi-model ensemble mean precipitation forecast (2017–2021) for days 8–14 (week-2 forecast) is used as a covariate in logistic regression models to predict fire risk in the Amazon. In a complementary experiment, a vegetation health index (VHI) is added to SubX precipitation forecasts as a predictor of fires. We find that fire risk can be skillfully assessed in most of the Amazon where fires occur regularly. In some sectors, SubX week-2 precipitation alone is a reliable predictor of fire risk, but the addition of VHI as a predictor results both in (a) a larger portion of the Amazon domain with skillful forecasts and; (b) higher skill in some sectors. By comparing two sectors of the Amazon, we find that the added information provided by VHI is most relevant where the mosaic of land covers includes savannas and grassland, whereas SubX precipitation can be used as the sole predictor for week-2 fire risk forecast in areas where the mosaic of land cover is dominated by forests. Our results illustrate the potential for using numerical model forecasts, at the subseasonal timescale, in combination with satellite remote sensing of vegetation to obtain skillful fire risk forecasts in the Amazon. The operationalization of the methods presented in this study could allow for better preparedness and fire risk reduction in the Amazon with a lead time greater than a week.}, number={7}, journal={Environmental Research Letters}, publisher={IOP Publishing}, author={Fernandes, Kátia and Bell, Michael and Muñoz, Ángel G}, year={2022}, month={Jul}, pages={074009} }
 @article{venturieri_oliveira_igawa_fernandes_adami_júnior_almeida_silva_cabral_pinto_et al._2022, title={The Sustainable Expansion of the Cocoa Crop in the State of Pará and Its Contribution to Altered Areas Recovery and Fire Reduction}, url={http://dx.doi.org/10.4236/jgis.2022.143016}, DOI={10.4236/jgis.2022.143016}, abstractNote={The state of Pará, located in the Amazon region of Brazil, has observed in recent years an increase in cocoa ( Theobroma cacao ) cultivation and has become the largest producer in Brazil. Due to its physiological characteristics, cacao is cultivated in native forests understory or under the shade produced by fast-growing native tree species, serving as an important species for restoration of degraded areas. However, mapping and monitoring cocoa plantation using optical sensor images is a challenge given its botanical and arboreal characteristics that can be confused with other native species at various stages of secondary regrowth. Agroforestry systems are important components of sustainable production in the Amazon and our work sought to better describe the evolution of cocoa plantations in terms of their historical expansion, farming properties}, journal={Journal of Geographic Information System}, author={Venturieri, Adriano and Oliveira, Rodrigo Rafael Souza and Igawa, Tassio Koiti and Fernandes, Katia De Avila and Adami, Marcos and Júnior, M. and Almeida, Cláudio Aparecido and Silva, Luiz Guilherme Teixeira and Cabral, Ana I. R. and Pinto, João Felipe Kneipp Cerqueira and et al.}, year={2022} }
 @article{saatchi_longo_xu_yang_abe_andré_aukema_carvalhais_cadillo-quiroz_cerbu_et al._2021, title={Detecting vulnerability of humid tropical forests to multiple stressors}, volume={4}, DOI={10.1016/j.oneear.2021.06.002}, abstractNote={Humid tropical forests play a dominant role in the functioning of Earth but are under increasing threat from changes in land use and climate. How forest vulnerability varies across space and time and what level of stress forests can tolerate before facing a tipping point are poorly understood. Here, we develop a tropical forest vulnerability index (TFVI) to detect and evaluate the vulnerability of global tropical forests to threats across space and time. We show that climate change together with land-use change have slowed the recovery rate of forest carbon cycling. Temporal autocorrelation, as an indicator of this slow recovery, increases substantially for above-ground biomass, gross primary production, and evapotranspiration when climate stress reaches a critical level. Forests in the Americas exhibit extensive vulnerability to these stressors, while in Africa, forests show relative resilience to climate, and in Asia reveal more vulnerability to land use and fragmentation. TFVI can systematically track the response of tropical forests to multiple stressors and provide early-warning signals for regions undergoing critical transitions.}, number={7}, journal={One Earth}, publisher={Elsevier BV}, author={Saatchi, Sassan and Longo, Marcos and Xu, Liang and Yang, Yan and Abe, Hitofumi and André, Michel and Aukema, Juliann E. and Carvalhais, Nuno and Cadillo-Quiroz, Hinsby and Cerbu, Gillian Ann and et al.}, year={2021}, month={Jul}, pages={988–1003} }
 @article{granato‐souza_stahle_torbenson_howard_barbosa_feng_fernandes_schöngart_2020, title={Multidecadal Changes in Wet Season Precipitation Totals Over the Eastern Amazon}, volume={47}, url={https://doi.org/10.1029/2020GL087478}, DOI={10.1029/2020GL087478}, abstractNote={AbstractInstrumental observations indicate that Amazon precipitation and streamflow extremes have increased during the last 40 years, possibly due to anthropogenic changes and natural variability. How unprecedented these changes might be is difficult to determine because some paleoclimatic, instrumental, and climate model simulations suggest that Amazonian precipitation and streamflow may be subject to multidecadal variability with return intervals longer than most direct observations. A new 258‐year long tree‐ring chronology of Cedrela odorata has been developed in the eastern Amazon and has been used to reconstruct wet season precipitation totals from 1759–2016. Reconstructed drought extremes are associated with significant sea surface temperature anomalies over the tropical Pacific and Atlantic Oceans. Strong multidecadal variance is identified in the reconstruction that may reflect a component of natural rainfall variability relevant to forest ecosystem dynamics and suggesting that recent hydroclimate changes over the eastern Amazon may not be unprecedented over the past 258 years.}, number={8}, journal={Geophysical Research Letters}, publisher={American Geophysical Union (AGU)}, author={Granato‐Souza, Daniela and Stahle, David W. and Torbenson, Max C.A. and Howard, Ian M. and Barbosa, Ana Carolina and Feng, Song and Fernandes, Katia and Schöngart, Jochen}, year={2020}, month={Apr} }
 @article{david_torbenson_howard_granato-souza_barbosa_feng_schöngart_lopez_villalba_villanueva_et al._2020, title={Pan American interactions of Amazon precipitation, streamflow, and tree growth extremes}, url={http://dx.doi.org/10.1088/1748-9326/ababc6}, DOI={10.1088/1748-9326/ababc6}, abstractNote={Abstract
               Rainfall and river levels in the Amazon are associated with significant precipitation anomalies of opposite sign in temperate North and South America, which is the dominant mode of precipitation variability in the Americas that often arises during extremes of the El Niño/Southern Oscillation (ENSO). This co-variability of precipitation extremes across the Americas is imprinted on tree growth and is detected when new tree-ring chronologies from the eastern equatorial Amazon are compared with hundreds of moisture-sensitive tree-ring chronologies in mid-latitude North and South America from 1759 to 2016. Pan-American co-variability exists even though the seasonality of precipitation and tree growth only partially overlaps between the Amazon and mid-latitudes because ENSO forcing of climate can persist for multiple seasons and can orchestrate a coherent response, even where the growing seasons are not fully synchronized. The tree-ring data indicate that the El Niño influence on inter-hemispheric precipitation and tree growth extremes has been strong and stable over the past 258-years, but the La Niña influence has been subject to large multi-decadal changes. These changes have implications for the dynamics and forecasting of hydroclimatic variability over the Americas and are supported by analyses of the available instrumental data and selected climate model simulations.}, journal={Environmental Research Letters}, author={David and Torbenson, M C A and Howard, I M and Granato-Souza, Daniela and Barbosa, A C and Feng, S and Schöngart, J and Lopez, L and Villalba, R and Villanueva, J and et al.}, year={2020}, month={Oct} }
 @article{improving seasonal precipitation forecast for agriculture in the orinoquía region of colombia_2019, url={http://dx.doi.org/10.1175/waf-d-19-0122.1}, DOI={10.1175/waf-d-19-0122.1}, abstractNote={Abstract
               Canonical correlation analysis (CCA) is used to improve the skill of seasonal forecasts in the Orinoquía region, where over 40% of Colombian rice is produced. Seasonal precipitation and frequency of wet days are predicted, as rice yields simulated by a calibrated crop model are better correlated with wet-day frequency than with precipitation amounts in June–August (JJA). Prediction of the frequency of wet days, using as predictors variables from the NCEP Climate Forecast System, version 2 (CFSv2), results in a forecast with higher skill than models predicting seasonal precipitation amounts. Using wet-day frequency as an alternative climate variable reveals that the distribution of daily rainfall is both more relevant for rice yield variability and more skillfully predicted than seasonal precipitation amounts. Forecast skill can also be improved by using the Climate Hazards Infrared Precipitation with Stations (CHIRPS) merged satellite–station JJA precipitation as the predictand in a CCA model, especially if the predictor is CFSv2 vertically integrated meridional moisture flux (VQ). The probabilistic hindcast derived from the CCA model using CHIRPS as the predictand can successfully discriminate above-normal, normal, and below-normal terciles of over 80% of the stations in the region. This is particularly relevant for stations that, due to discontinuity in their time series, are not included in station-only CCA models but are still in need of probabilistic seasonal forecasts. Finally, CFSv2 VQ performs better than precipitation as the predictor in CCA, which we attribute to CFSv2 being more internally consistent in regards to sea surface temperature (SST)-forced VQ variability than to SST-forced precipitation variability in the Orinoquía region.}, journal={Weather and Forecasting}, year={2019}, month={Dec} }
 @article{predictability of seasonal precipitation across major crop growing areas in colombia_2018, url={http://dx.doi.org/10.1016/j.cliser.2018.09.001}, DOI={10.1016/j.cliser.2018.09.001}, abstractNote={Agriculture is one of the sectors that has greatly benefitted from the establishment of climate services. In Colombia, interannual climate variability can disrupt agricultural production, lower farmers' incomes and increase market prices. Increasing demand thus exists for agro-climatic services in the country. Fulfilling such demand requires robust and consistent approaches for seasonal climate forecasting. Here, we assess seasonal precipitation predictability and forecast skill at agriculturally-relevant timescales for five departments that represent key growing areas of major staple crops (rice, maize, and beans). Analyses use Canonical Correlation Analysis, with both observed SSTs and modeled (NCEP-CFSv2) SSTs, as well as with CFSv2 predicted precipitation fields (through a Model-Output-Statistics analysis). Some 74.4% of the forecast situations analyzed (5 departments ∗ 4 seasons ∗ 3 predictors ∗ 3 lead times) showed correlation-based goodness index (Kendall's tau, τ-) values above 0.1, 38.8% above 0.2, and 18.8% above 0.3. Predictability was limited towards eastern Colombia, and during wet periods of the year in the Inter-Andean Valleys. Importantly, results were consistent between ERSST and CFSv2-driven forecasts, implying that both can offer valuable outlooks for Colombia. While our study is a first important step toward the establishment of a sustainable and successful climate service for agriculture in Colombia, further work is required to (1) improve seasonal forecast skill; (2) link seasonal forecasts to agricultural modelling applications; (3) design appropriate delivery means; and (4) establish stakeholder-driven processes that allow two-way communication between forecast issuing institutions (e.g. IDEAM–Colombian Meteorological Service) and famers' organizations and farming communities.}, journal={Climate Services}, year={2018}, month={Dec} }
 @article{understanding the roles of fuels, climate and people in predicting fire: taking the long view_2018, url={http://dx.doi.org/10.22498/pages.26.1.41}, DOI={10.22498/pages.26.1.41}, journal={Past Global Changes Magazine}, year={2018}, month={Jun} }
 @article{climate change and sugarcane expansion increase hantavirus infection risk_2017, url={http://dx.doi.org/10.1371/journal.pntd.0005705}, DOI={10.1371/journal.pntd.0005705}, abstractNote={Hantavirus Cardiopulmonary Syndrome (HCPS) is a disease caused by Hantavirus, which is highly virulent for humans. High temperatures and conversion of native vegetation to agriculture, particularly sugarcane cultivation can alter abundance of rodent generalist species that serve as the principal reservoir host for HCPS, but our understanding of the compound effects of land use and climate on HCPS incidence remains limited, particularly in tropical regions. Here we rely on a Bayesian model to fill this research gap and to predict the effects of sugarcane expansion and expected changes in temperature on Hantavirus infection risk in the state of São Paulo, Brazil. The sugarcane expansion scenario was based on historical data between 2000 and 2010 combined with an agro-environment zoning guideline for the sugar and ethanol industry. Future evolution of temperature anomalies was derived using 32 general circulation models from scenarios RCP4.5 and RCP8.5 (Representative greenhouse gases Concentration Pathways adopted by IPCC). Currently, the state of São Paulo has an average Hantavirus risk of 1.3%, with 6% of the 645 municipalities of the state being classified as high risk (HCPS risk ≥ 5%). Our results indicate that sugarcane expansion alone will increase average HCPS risk to 1.5%, placing 20% more people at HCPS risk. Temperature anomalies alone increase HCPS risk even more (1.6% for RCP4.5 and 1.7%, for RCP8.5), and place 31% and 34% more people at risk. Combined sugarcane and temperature increases led to the same predictions as scenarios that only included temperature. Our results demonstrate that climate change effects are likely to be more severe than those from sugarcane expansion. Forecasting disease is critical for the timely and efficient planning of operational control programs that can address the expected effects of sugarcane expansion and climate change on HCPS infection risk. The predicted spatial location of HCPS infection risks obtained here can be used to prioritize management actions and develop educational campaigns.}, journal={PLOS Neglected Tropical Diseases}, year={2017}, month={Jul} }
 @article{fragmentation increases wind disturbance impacts on forest structure and carbon stocks in a western amazonian landscape_2017, url={http://dx.doi.org/10.1002/eap.1576}, DOI={10.1002/eap.1576}, abstractNote={AbstractTropical second‐growth forests could help mitigate climate change, but the degree to which their carbon potential is achieved will depend on exposure to disturbance. Wind disturbance is common in tropical forests, shaping structure, composition, and function, and influencing successional trajectories. However, little is known about the impacts of extreme winds on second‐growth forests in fragmented landscapes, though these ecosystems are often located in mosaics of forest, pasture, cropland, and other land cover types. Indirect evidence suggests that fragmentation increases risk of wind damage in tropical forests, but no studies have found such impacts following severe storms. In this study, we ask whether fragmentation and forest type (old vs. second growth) were associated with variation in wind damage after a severe convective storm in a fragmented production landscape in western Amazonia. We applied linear spectral unmixing to Landsat 8 imagery from before and after the storm, and combined it with field observations of damage to map wind effects on forest structure and biomass. We also used Landsat 8 imagery to map land cover with the goals of identifying old‐ and second‐growth forest and characterizing fragmentation. We used these data to assess variation in wind disturbance across 95,596 ha of forest, distributed over 6,110 patches. We find that fragmentation is significantly associated with wind damage, with damage severity higher at forest edges and in edgier, more isolated patches. Damage was also more severe in old‐growth than in second‐growth forests, but this effect was weaker than that of fragmentation. These results illustrate the importance of considering landscape context in planning tropical forest restoration and natural regeneration projects. Assessments of long‐term carbon sequestration potential need to consider spatial variation in disturbance exposure. Where risk of extreme winds is high, minimizing fragmentation and isolation could increase carbon sequestration potential.}, journal={Ecological Applications}, year={2017}, month={Sep} }
 @article{heightened fire probability in indonesia in non-drought conditions: the effect of increasing temperatures_2017, url={http://dx.doi.org/10.1088/1748-9326/aa6884}, DOI={10.1088/1748-9326/aa6884}, abstractNote={In Indonesia, drought driven fires occur typically during the warm phase of the El Niño Southern Oscillation. This was the case of the events of 1997 and 2015 that resulted in months-long hazardous atmospheric pollution levels in Equatorial Asia and record greenhouse gas emissions. Nonetheless, anomalously active fire seasons have also been observed in non-drought years. In this work, we investigated the impact of temperature on fires and found that when the July-October (JASO) period is anomalously dry, the sensitivity of fires to temperature is modest. In contrast, under normal-to-wet conditions, fire probability increases sharply when JASO is anomalously warm. This describes a regime in which an active fire season is not limited to drought years. Greater susceptibility to fires in response to a warmer environment finds support in the high evapotranspiration rates observed in normal-to-wet and warm conditions in Indonesia. We also find that fire probability in wet JASOs would be considerably less sensitive to temperature were not for the added effect of recent positive trends. Near-term regional climate projections reveal that, despite negligible changes in precipitation, a continuing warming trend will heighten fire probability over the next few decades especially in non-drought years. Mild fire seasons currently observed in association with wet conditions and cool temperatures will become rare events in Indonesia.}, journal={Environmental Research Letters}, year={2017}, month={May} }
 @article{local ecological knowledge and incremental adaptation to changing flood patterns in the amazon delta_2016, url={http://dx.doi.org/10.1007/s11625-015-0352-2}, DOI={10.1007/s11625-015-0352-2}, journal={Sustainability Science}, year={2016}, month={Jul} }
 @article{climate, landowner residency, and land cover predict local scale fire activity in the western amazon_2015, url={http://dx.doi.org/10.1016/j.gloenvcha.2015.01.009}, DOI={10.1016/j.gloenvcha.2015.01.009}, abstractNote={The incidence of escaped agricultural fire has recently been increasing in the Western Amazon, driven by climate variability, land use change, and changes in patterns of residency and land occupation. Preventing and mitigating the negative impacts of fire in the Amazon require a comprehensive understanding not only of what the drivers of fire activity are, but also how these drivers interact and vary across scales. Here, we combine multi-scalar data on land use, climate, and landowner residency to disentangle the drivers of fire activity over 10 years (2001–2010) on individual landholdings in a fire-prone region of the Peruvian Amazon. We examined the relative importance of and interactions between climate variability (drought intensity), land occupation (in particular, landowner absenteeism), and land cover variables (cover of fallow and pasture) for predicting both fire occurrence (whether or not fire was detected on a farm in a given year) and fire size. Drought intensity was the most important predictor of fire occurrence, but land-cover type and degree of landowner absenteeism increased fire probability when conditions were dry enough. On the other hand, drought intensity did not stand out relative to other significant predictors in the fire size model, where degree of landowner absenteeism in a village and percent cover of fallow in a village were also strongly associated with fire size. We also investigated to what extent these variables measured at the individual landholding versus the village scale influenced fire activity. While the predictors measured at the landholding and village scales were approximately of equal importance for modeling fire occurrence, only village scale predictors were important in the model of fire size. These results demonstrate that the relative importance of various drivers of fire activity can vary depending on the scale at which they are measured and the scale of analysis. Additionally, we highlight how a full understanding of the drivers of fire activity should go beyond fire occurrence to consider other metrics of fire activity such as fire size, as implications for fire prevention and mitigation can be different depending on the model considered. Drought early warning systems may be most effective for preventing fire in dry years, but management to address the impacts of landowner absenteeism, such as bolstering community fire control efforts in high-risk areas, could help minimize the size of fires when they do occur. Thus, interventions should focus on minimizing fire size as well as preventing fires altogether, especially because fire is an inexpensive and effective management tool that has been in use for millennia.}, journal={Global Environmental Change}, year={2015}, month={Mar} }
 @article{fernandes_giannini_verchot_baethgen_pinedo‐vasquez_2015, title={Decadal covariability of Atlantic SSTs and western Amazon dry‐season hydroclimate in observations and CMIP5 simulations}, volume={42}, url={https://doi.org/10.1002/2015GL063911}, DOI={10.1002/2015GL063911}, abstractNote={AbstractThe unusual severity and return time of the 2005 and 2010 dry‐season droughts in western Amazon is attributed partly to decadal climate fluctuations and a modest drying trend. Decadal variability of western Amazon hydroclimate is highly correlated to the Atlantic sea surface temperature (SST) north‐south gradient (NSG). Shifts of dry and wet events frequencies are also related to the NSG phase, with a 66% chance of 3+ years of dry events per decade when NSG > 0 and 19% when NSG < 0. The western Amazon and NSG decadal covariability is well reproduced in general circulation models (GCMs) historical (HIST) and preindustrial control (PIC) experiments of the Coupled Model Intercomparison Project Phase 5 (CMIP5). The HIST and PIC also reproduce the shifts in dry and wet events probabilities, indicating potential for decadal predictability based on GCMs. Persistence of the current NSG positive phase favors above normal frequency of western Amazon dry events in coming decades.}, number={16}, journal={Geophysical Research Letters}, publisher={American Geophysical Union (AGU)}, author={Fernandes, Katia and Giannini, Alessandra and Verchot, Louis and Baethgen, Walter and Pinedo‐Vasquez, Miguel}, year={2015}, month={Aug}, pages={6793–6801} }
 @article{seth_fernandes_camargo_2015, title={Two summers of São Paulo drought: Origins in the western tropical Pacific}, url={http://dx.doi.org/10.1002/2015gl066314}, DOI={10.1002/2015gl066314}, abstractNote={AbstractTwo years of drought in Southeast Brazil have led to water shortages in São Paulo, the country's most populous city. We examine the observed drought during austral summers of 2013/2014 and 2014/2015 and the related large‐scale dynamics. The 2013–2014 precipitation deficits were more concentrated in the state of São Paulo, while in 2014–2015 moderate deficits were seen throughout the region. We find that a persistent warm sea surface temperature (SST) anomaly in the western tropical Pacific Ocean was an important driver of drought via atmospheric teleconnection in the two December–February seasons. The warm SST and associated convective heating initiated a wave train across the South Pacific. The resulting anticyclonic geopotential height anomaly over the southwest Atlantic expanded the westward margin of the South Atlantic high and prevented low‐pressure systems from entering southeast Brazil from midlatitudes. This mechanism suggests a hemispheric symmetry to that proposed for the recent California drought.}, journal={Geophysical Research Letters}, author={Seth, Anji and Fernandes, Kátia and Camargo, Suzana J.}, year={2015}, month={Dec} }
 @article{climate and environmental monitoring for decision making_2014, url={http://dx.doi.org/10.1186/2194-6434-1-16}, DOI={10.1186/2194-6434-1-16}, abstractNote={As human populations grow, so do the resource demands imposed on ecosystems and the impacts of our global footprint. Natural resources are not invulnerable, nor infinitely available. The environmental impacts of anthropogenic actions are becoming more apparent – air and water quality are increasingly compromised, pests and diseases are extending beyond their historical boundaries, and deforestation is exacerbating flooding downstream and loss of biodiversity. Society is increasingly becoming aware that ecosystem services are not only limited, but also that they are threatened by human activities. The need to better consider long-term ecosystem health and its role in enabling human habitation and economic activity is urgent. In this context IRI conducts research to understand the impact of climate and environmental changes on different sectors including agriculture, water management, human health, and natural disasters. Through exhaustive, rigorous evaluation, analysis and interpretation of remotely-sensed products and in-situ measurements, IRI ensures its partners have access to the most reliable and relevant information about the climate and environment in a format that best informs their decision making and planning. We focus on monitoring satellite-derived and in-situ estimates of precipitation, temperature, vegetation, water bodies, evapotranspiration, and land cover. Ultimately, the new products developed at IRI in partnership with other institutions at national (e.g. NOAA, NASA, USGS) and international (e.g. National Meteorology Agencies, UN FAO) levels are integrated into operational early-warning systems for health, natural disasters, agriculture, and food security. The new products which monitor in almost real-time climate and environmental conditions are made available through two online data bases at IRI called IRI Data Library and Map Room. In this paper we present the products developed at IRI and how they are integrated into Early Warning Systems (EWS). We also discuss IRI's experience in linking EWS into decisions and policies using the fire early warning system as a concrete example.}, journal={Earth Perspectives}, year={2014} }
 @article{gutiérrez-vélez_uriarte_defries_pinedo-vásquez_fernandes_ceccato_baethgen_padoch_2014, title={Land cover change interacts with drought severity to change fire regimes in Western Amazonia}, url={http://dx.doi.org/10.1890/13-2101.1}, DOI={10.1890/13-2101.1}, abstractNote={Fire is becoming a pervasive driver of environmental change in Amazonia and is expected to intensify, given projected reductions in precipitation and forest cover. Understanding of the influence of post‐deforestation land cover change on fires in Amazonia is limited, even though fires in cleared lands constitute a threat for ecosystems, agriculture, and human health. We used MODIS satellite data to map burned areas annually between 2001 and 2010. We then combined these maps with land cover and climate information to understand the influence of land cover change in cleared lands and dry‐season severity on fire occurrence and spread in a focus area in the Peruvian Amazon. Fire occurrence, quantified as the probability of burning of individual 232‐m spatial resolution MODIS pixels, was modeled as a function of the area of land cover types within each pixel, drought severity, and distance to roads. Fire spread, quantified as the number of pixels burned in 3 × 3 pixel windows around each focal burned pixel, was modeled as a function of land cover configuration and area, dry‐season severity, and distance to roads. We found that vegetation regrowth and oil palm expansion are significantly correlated with fire occurrence, but that the magnitude and sign of the correlation depend on drought severity, successional stage of regrowing vegetation, and oil palm age. Burning probability increased with the area of nondegraded pastures, fallow, and young oil palm and decreased with larger extents of degraded pastures, secondary forests, and adult oil palm plantations. Drought severity had the strongest influence on fire occurrence, overriding the effectiveness of secondary forests, but not of adult plantations, to reduce fire occurrence in severely dry years. Overall, irregular and scattered land cover patches reduced fire spread but irregular and dispersed fallows and secondary forests increased fire spread during dry years. Results underscore the importance of land cover management for reducing fire proliferation in this landscape. Incentives for promoting natural regeneration and perennial crops in cleared lands might help to reduce fire risk if those areas are protected against burning in early stages of development and during severely dry years.}, journal={Ecological Applications}, author={Gutiérrez-Vélez, Víctor H. and Uriarte, María and DeFries, Ruth and Pinedo-Vásquez, Miguel and Fernandes, Katia and Ceccato, Pietro and Baethgen, Walter and Padoch, Christine}, year={2014}, month={Sep} }
 @article{what controls the interannual variation of the wet season onsets over the amazon?_2014, url={http://dx.doi.org/10.1002/2013jd021349}, DOI={10.1002/2013jd021349}, abstractNote={AbstractPrevious studies have established that sea surface temperature anomalies (SSTAs) in the tropical Pacific and Atlantic are the main forcing of the interannual variation of the wet season onsets in the Amazon. However, this variation appears to be complex and not uniquely determined by SSTAs. What causes such a complexity and to what extent the interannual variation of the wet season onsets is predictable remain unclear. This study suggests that such a complex relationship is the result of several competing processes, which are nonlinearly related to the SSTAs. In particular, three dry season conditions are crucial for determining interannual variation of the wet season onset. (i) A poleward shift of the Southern Hemisphere subtropical jet (SHSJ) over the South American sector, initiated from a wave train‐like structure possibly forced by south central Pacific SST patterns, can prevent cold frontal systems from moving northward into the Amazon. This delays cold air incursion and results in late wet season onset over the southern Amazon. (ii) An anomalous anticyclonic center, which enhances westerly wind at 850 hPa over the southern Amazon and also the South American low‐level jets, leads to moisture export from the southern Amazon to La Plata basin and reduces convective systems that provide elevated diabatic heating. (iii) Smaller convective available potential energy (CAPE) limits local thermodynamically driven convection. Based on the stepwise and partial least squares regressions, these three selected preseasonal conditions (Niño 4, SHSJ, and CAPE) can explain 57% of the total variance of the wet season onset.}, journal={Journal of Geophysical Research: Atmospheres}, year={2014}, month={Mar} }
 @article{increased dry-season length over southern amazonia in recent decades and its implication for future climate projection_2013, url={http://dx.doi.org/10.1073/pnas.1302584110}, DOI={10.1073/pnas.1302584110}, abstractNote={Significance
          
            Whether the dry-season length will increase is a central question in determining the fate of the rainforests over Amazonia and the future global atmospheric CO
            2
            concentration. We show observationally that the dry-season length over southern Amazonia has increased significantly since 1979. We do not know what has caused this change, although it resembles the effects of anthropogenic climate change. The global climate models that were presented in the Intergovernmental Panel on Climate Change’s fifth assessment report seem to substantially underestimate the variability of the dry-season length. Such a bias implies that the future change of the dry-season length, and hence the risk of rainforest die-back, may be underestimated by the projections of these models.
          }, journal={Proceedings of the National Academy of Sciences}, year={2013}, month={Nov} }
 @article{depopulation of rural landscapes exacerbates fire activity in the western amazon_2012, url={http://dx.doi.org/10.1073/pnas.1215567110}, DOI={10.1073/pnas.1215567110}, abstractNote={Destructive fires in Amazonia have occurred in the past decade, leading to forest degradation, carbon emissions, impaired air quality, and property damage. Here, we couple climate, geospatial, and province-level census data, with farmer surveys to examine the climatic, demographic, and land use factors associated with fire frequency in the Peruvian Amazon from 2000 to 2010. Although our results corroborate previous findings elsewhere that drought and proximity to roads increase fire frequency, the province-scale analysis further identifies decreases in rural populations as an additional factor. Farmer survey data suggest that increased burn scar frequency and size reflect increased flammability of emptying rural landscapes and reduced capacity to control fire. With rural populations projected to decline, more frequent drought, and expansion of road infrastructure, fire risk is likely to increase in western Amazonia. Damage from fire can be reduced through warning systems that target high-risk locations, coordinated fire fighting efforts, and initiatives that provide options for people to remain in rural landscapes.}, journal={Proceedings of the National Academy of Sciences}, year={2012}, month={Dec} }
 @article{roseghini_mendonça_ceccato_fernandes_2011, title={DENGUE EPIDEMICS IN MIDDLE-SOUTH OF BRAZIL: CLIMATE CONSTRAINTS AND SOME SOCIAL ASPECTS}, url={http://dx.doi.org/10.5380/abclima.v9i0.27522}, DOI={10.5380/abclima.v9i0.27522}, abstractNote={A dengue é atualmente um dos mais graves problemas de saúde pública em todo o mundo. É uma doença do mundo tropical, no qual a maioria da América Latina está localizada e onde o ambiente e o clima proporcionam condições ideais para o mosquito Aedes (aegypti e albopictus) para prosperar. Além disso, o ambiente sócio-cultural (urbanização e estilo de vida) e a ineficácia das políticas públicas de saúde, resultam em graves epidemias da doença. Esta pesquisa tem como analise a incidência de dengue em três diferentes cidades do Brasil: Campo Grande / MS, Maringá / PR e Ribeirão Preto / SP e sua relação estatística com o clima, correlacionando variáveis climáticas diferentesde incidência da doença. A análise da temperatura diária também mostra correlação significativa (R = 0,70 e P> 0,99) com os registros da doença e um atraso 7 dias. Além do clima e factores ambientais, a mobilidade da população em relação aos casos importados também foi investigada. Os resultados mostram a complexidade da doença, em uma relação estreita entre o ambiente (clima) e a mobilidade da população, a circulação de differente sorotipos, a eliminação de resíduos sólidos, entulho e piscinas abandonadas, o que coloca a própria população em situações de risco e vulnerabilidade à doença. Um ponto importante a destacar é que, mesmo em cidades diferentes, a epidemia seguiu um padrão semelhante, enfatizando a importância das variáveis climáticas. Este estudo mostra importantes relações entre as epidemias de dengue e clima, embora estudos mais detalhados sobre ambos sorotipo e transmissão nas cidades são necessários para melhor entender os fatores por trás da transmissão da doença. Nossos resultados podem ajudar as agências de saúde locais na implementação adequada de alerta precoce a partir de sistemas de monitoramento e ações preventivas de controle de condições de ambientais.}, journal={Revista Brasileira de Climatologia}, author={Roseghini, Wilson Flavio Feltrim and Mendonça, Francisco and Ceccato, Pietro and Fernandes, Katia}, year={2011}, month={Dec} }
 @article{high-yield oil palm expansion spares land at the expense of forests in the peruvian amazon_2011, url={http://dx.doi.org/10.1088/1748-9326/6/4/044029}, DOI={10.1088/1748-9326/6/4/044029}, abstractNote={Abstract
               High-yield agriculture potentially reduces pressure on forests by requiring less land
               to increase production. Using satellite and field data, we assessed the area
               deforested by industrial-scale high-yield oil palm expansion in the Peruvian Amazon
               from 2000 to 2010, finding that 72% of new plantations expanded into forested areas.
               In a focus area in the Ucayali region, we assessed deforestation for high- and
               smallholder low-yield oil palm plantations. Low-yield plantations accounted for most
               expansion overall (80%), but only 30% of their expansion involved forest conversion,
               contrasting with 75% for high-yield expansion. High-yield expansion minimized the
               total area required to achieve production but counter-intuitively at higher expense
               to forests than low-yield plantations. The results show that high-yield agriculture
               is an important but insufficient strategy to reduce pressure on forests. We suggest
               that high-yield agriculture can be effective in sparing forests only if coupled with
               incentives for agricultural expansion into already cleared lands.}, journal={Environmental Research Letters}, year={2011}, month={Jan} }
 @article{north tropical atlantic influence on western amazon fire season variability_2011, url={http://dx.doi.org/10.1029/2011gl047392}, DOI={10.1029/2011gl047392}, abstractNote={The prevailing wet climate in the western Amazon is not favorable to the natural occurrence of fires. Nevertheless, the current process of clearing of humid forests for agriculture and cattle ranching has increased the vulnerability of the region to the spread of fires. Using meteorological stations precipitation and the Moderate Resolution Spectroradiometer (MODIS) Active‐Fires (AF) during 2000–2009, we show that fire anomalies vary closely with July‐August‐September (JAS) precipitation variability as measured by the Standardized Precipitation Index (SPI). The precipitation variability is, in turn, greatly determined by sea surface temperature (SST) anomalies in the North Tropical Atlantic (NTA). We develop a linear regression model to relate local fire activity to an index of the NTA‐SST. By using seasonal forecasts of SST from a coupled model, we are able to predict anomalous JAS fire activity as early as April. We applied the method to predict the severe 2010 JAS season, which indicated strongly positive seasonal fire anomalies within the 95% prediction confidence intervals in most western Amazon. The spatial distribution of predicted SPI was also in accordance with observed precipitation anomalies. This three months lead time precipitation and fire prediction product in the western Amazon could help local decision makers to establish an early warning systems or other appropriate course of action before the fire season begins.}, journal={Geophysical Research Letters}, year={2011}, month={Jun} }
 @article{impact of biomass burning aerosol on the monsoon circulation transition over amazonia_2009, url={http://dx.doi.org/10.1029/2009gl037180}, DOI={10.1029/2009gl037180}, abstractNote={Ensemble simulations of a regional climate model (RegCM3) forced by aerosol radiative forcing suggest that biomass burning aerosols can work against the seasonal monsoon circulation transition, thus re‐enforce the dry season rainfall pattern for Southern Amazonia. Strongly absorbing smoke aerosols warm and stabilize the lower troposphere within the smoke center in southern Amazonia (where aerosol optical depth >0.3). These changes increase the surface pressure in the smoke center, weaken the southward surface pressure gradient between northern and southern Amazonia, and consequently induce an anomalous moisture divergence in the smoke center and an anomalous convergence in northwestern Amazonia (5°S‐5°N, 60°W‐70°W). The increased atmospheric thermodynamic stability, surface pressure, and divergent flow in Southern Amazonia may inhibit synoptic cyclonic activities propagated from extratropical South America, and re‐enforce winter‐like synoptic cyclonic activities and rainfall in southeastern Brazil, Paraguay and northeastern Argentina.}, journal={Geophysical Research Letters}, year={2009}, month={May} }
 @article{comparison of precipitation datasets over the tropical south american and african continents_2009, url={http://dx.doi.org/10.1175/2008jhm1023.1}, DOI={10.1175/2008jhm1023.1}, abstractNote={Abstract
               Six rainfall datasets are compared over the Amazon basin, Northeast Brazil, and the Congo basin. These datasets include three gauge-only precipitation products from the Climate Prediction Center (CPC), Global Precipitation Climatology Center (GPCC), and Brazilian Weather Forecast and Climate Studies Center (CLMNLS), and three combined gauge and satellite precipitation datasets from the CPC Merged Analysis of Precipitation (CMAP), Global Precipitation Climatology Project (GPCP), and Tropical Rainfall Measuring Mission (TRMM) product. The pattern of the annual precipitation is consistently represented by these data, despite the differences in methods and periods of averaging. Quantitatively, the differences in annual precipitation among these datasets are 5% more than the Amazon domain (0°–15°S, 50°–70°W), 22% more than Northeast Brazil (5°–10°S, 35°–45°W), and 11% more than the Congo domain (5°N–10°S, 15°–30°E). Over the Amazon domain the rainfall variation is well correlated between CPC, TRMM, GPCP, and GPCC (r 2 > 0.9) except for the northwestern Amazon, whereas CMAP and CLMNLS were different from these four datasets. Over the Congo basin, the coefficient of determination between these rainfall datasets is generally below 0.7. The empirical orthogonal functions analysis suggests large discrepancies in interannual and decadal variations of rainfall among these datasets, especially for the Congo basin and for the South American region after 1998. In general, CMAP, GPCC, TRMM, and GPCP significantly agree over the tropical areas in South America.}, journal={Journal of Hydrometeorology}, year={2009}, month={Feb} }
 @article{how well does the era40 surface water budget compare to observations in the amazon river basin?_2008, url={http://dx.doi.org/10.1029/2007jd009220}, DOI={10.1029/2007jd009220}, abstractNote={The surface water budget of the Amazon River basin derived from the ERA40 reanalysis is evaluated by comparing it with observed precipitation (P), streamflow/runoff (R), and evapotranspiration (ET) data sets for the period of 1980–2002. The rainfall is averaged over 90% of the Amazon River basin, corresponding to the catchments of the Óbidos and Altamira streamflow gauges. The annual rainfall and the interannual changes from ERA40 fall within the range of the two precipitation data sets. On the seasonal timescale, ERA40 reproduces well the rainfall during the dry and transition seasons, but it underestimates the wet season rainfall by 4–11% when compared with the two precipitation data sets. On the subbasin scale, the disparity in precipitation between ERA40 and observations is as much as ±40%. The annual runoff integrated over the two catchments is underestimated in ERA40 by 25%. The rain‐rates in ERA40, which affect both throughfall and runoff, are comparable to those measured by the Tropical Rainfall Measurement Mission (TRMM 3B42V6), when these are rescaled to the resolution of the 2.5° ERA40 data. However, even the native resolution of ERA40 (∼1.125°) is greater than the scale of tropical convection. ET in ERA40 appears to be higher than observations by about 20%, although observed ET may have a 10% low bias. The difference between precipitation and runoff, P‐R, in ERA40 generally agrees with observations. However, annual ERA40 ET is greater than P‐R, because soil moisture nudging adds water to the soil. On the seasonal scale, soil moisture nudging is largest during the dry season, because ERA40 provides only a 45 mm surplus of P‐R relative to ET during the wet season, whereas the deficit in the dry season is almost four times greater. This low bias in wet season soil moisture recharge may be caused by the underestimation of wet season rainfall in ERA40. It is possible that the model interception may have a high bias, which contributes to the high ET in the rainy season and reduces the wet season storage.}, journal={Journal of Geophysical Research}, year={2008}, month={Jun} }
 @article{observed change of the standardized precipitation index, its potential cause and implications to future climate change in the amazon region_2008, url={http://dx.doi.org/10.1098/rstb.2007.0022}, DOI={10.1098/rstb.2007.0022}, abstractNote={
            Observations show that the standard precipitation index (SPI) over the southern Amazon region decreased in the period of 1970–1999 by 0.32 per decade, indicating an increase in dry conditions. Simulations of constant pre-industrial climate with recent climate models indicate a low probability (
            p
            =0%) that the trends are due to internal climate variability. When the 23 models are forced with either anthropogenic factors or both anthropogenic and external natural factors, approximately 13% of sampled 30-year SPI trends from the models are found to be within the range of the observed SPI trend at 95% confidence level. This suggests a possibility of anthropogenic and external forcing of climate change in the southern Amazon. On average, the models project no changes in the frequency of occurrence of low SPI values in the future; however, those models which produce more realistic SPI climatology, variability and trend over the period 1970–1999 show more of a tendency towards more negative values of SPI in the future. The analysis presented here suggests a potential anthropogenic influence on Amazon drying, which warrants future, more in-depth, study.
          }, journal={Philosophical Transactions of the Royal Society B: Biological Sciences}, year={2008}, month={May} }