This paper presents an overview of the results from the first major mesoscale atmospheric campaig... more This paper presents an overview of the results from the first major mesoscale atmospheric campaign of the Large-Scale Biosphere-Atmosphere Experiment in Amazonia (LBA) Program. The campaign, collocated with a Tropical Rainfall Measuring Mission (TRMM) satellite validation campaigns, was conducted in southwest Rondo ˆnia in January and February 1999 during the wet season. Highlights on the interaction between clouds, rain, and the underlying landscape through biospheric processes are presented and discussed.
Mitigation and Adaptation Strategies for Global Change, 2019
Climate change is a global phenomenon that affects biophysical systems and human wellbeing. The P... more Climate change is a global phenomenon that affects biophysical systems and human wellbeing. The Paris Agreement of the United Nations Framework Convention on Climate Change entered into force in 2016 with the objective of strengthening the global response to climate change by keeping global temperature rise this century well below 2 °C above pre-industrial levels and to pursue efforts to limit the temperature increase even further to 1.5 °C. The agreement requires all Parties to submit their "nationally determined contributions" (NDCs) and to strengthen these efforts in the years ahead. Reducing carbon emissions from deforestation and forest degradation is an important strategy for mitigating climate change, particularly in developing countries with large forests. Extensive tropical forest loss and degradation have increased awareness at the international level of the need to undertake large-scale ecological restoration, highlighting the need to identify cases in which restoration strategies can contribute to mitigation and adaptation. Here we consider Brazil as a case study to evaluate the benefits and challenges of implementing large-scale restoration programs in developing countries. The Brazilian NDC included the target of restoring and reforesting 12 million hectares of forests for multiple uses by 2030. Restoration of native vegetation is one of the foundations of sustainable rural development in Brazil and should consider multiple purposes, from biodiversity and ecosystem services conservation to social and economic development. However, ecological restoration still presents substantial challenges for tropical and megadiverse countries, including the need to develop plans that are technically and financially feasible, as well as public policies and monitoring instruments that can assess effectiveness. The planning, execution, and monitoring of restoration efforts strongly depend on the context and the diagnosis of the area with respect to reference ecosystems (e.g., forests, savannas, grasslands, wetlands). In addition, poor integration of climate change policies at the national and subnational levels and with other sectorial policies constrains the large-scale implementation of restoration programs. The case of Brazil shows that slowing deforestation is possible; however, this analysis highlights the need for increased national commitment and international support for actions that require large-scale transformations of the forest sector regarding ecosystem restoration efforts. Scaling up the ambitions and actions of the Paris Agreement implies the need for a global framework that recognizes landscape restoration as a costeffective nature-based solution and that supports countries in addressing their remaining needs, challenges, and barriers.
The impact of natural hazards on nations and societies is a global challenge and concern. Studies... more The impact of natural hazards on nations and societies is a global challenge and concern. Studies worldwide have been conducted within and among countries, to examine the spatial distribution and temporal evolution of fatalities and their consequences in societies. In Brazil, no studies have comprehensively identified fatalities associated with all natural hazards and their singularities by decade, region, sex, age, and other victim characteristics. This study develops a deep analysis on the Brazilian Data Mortality of the Brazilian Ministry of Health, from 1979 to 2019, identifying the natural hazards that kill the greatest number of people in Brazil and its surrounding particularities. Lightning is the deadliest natural hazard in Brazil during this period, with a gradual decrease in the number of fatal victims. Hydrogeological fatalities increases from 2000, and the most fatalities develop from 2010 to 2019. Despite Brazil being a tropical country affected by severe droughts, extr...
Drought is a complex natural phenomenon that can lead to reduced water supplies and can consequen... more Drought is a complex natural phenomenon that can lead to reduced water supplies and can consequently have substantial effects on agriculture and socioeconomic activities that cause social crises and political problems. Different drought indicators are used for identifying droughts. This work explored the applicability of a near-real time drought monitoring methodology using Terra-MODIS Normalized Difference Vegetation Index (NDVI) and land surface temperature (LST) products. This approach is called the Vegetation Supply Water Index (VSWI), which integrates land surface reflectance and thermal properties. The results indicate that during a major drought event from 2012 to 2013, approximately 85% of the Brazilian semiarid region was affected. The number of days of soil moisture deficit, which was derived from a simple water balance model and the daily interpolated precipitation, were used to verify the results. A correlation analysis of VSWI, precipitation and soil moisture deficit shows that VSWI is closely related to rainfall and soil water content, especially under dry conditions, and indicates that the use of VSWI can be a suitable near-real time drought monitoring approach. The evaluation of the 2012-2014 drought considering the VSWI index highlighted two major characteristics of vegetation response to drought conditions, i.e., the recovery and memory effects of vegetation.
Historically, during periods of extreme drought, food security in the drylands of the semiarid re... more Historically, during periods of extreme drought, food security in the drylands of the semiarid region of Northeast Brazil (NEB) is under severe risk due to agricultural collapse. The drought that started in 2012 continues to highlight the vulnerability of this region, and arid conditions have been detected during the last years mainly in the central semiarid region, covering almost 2% of the NEB. Climate projections show an increase in the area under water stress condition, covering 49% and 54% of the NEB region by 2700 and 2100, respectively, with a higher likelihood with warming above 4 °C. The projections of vegetative stress conditions derived from the empirical model for Vegetation Health Index (VHI) are consistent with projections from vegetation models, where semi-desert types typical of arid conditions would replace the current semiarid bushland vegetation ("caatinga") by 2100. Due to the impacts of the 2012-2017 drought, public policies have been implemented to reduce social and economic vulnerability for small farmers but are not enough as poor population continues to be affected. In the long term, to make the semiarid less vulnerable to drought, strengthened integrated water resources management and a proactive drought policy are needed to restructure the economy. Integrating drought monitoring and seasonal climate forecasting provides means of assessing impacts of climate variability and change, leading to disaster risk reduction through early warning. Lastly, there is an urgent need for integrated assessments because the possibility that under permanent drought conditions with warming above 4 °C, arid conditions would prevail in NEB since 2060.
This paper presents an overview of the results from the first major mesoscale atmospheric campaig... more This paper presents an overview of the results from the first major mesoscale atmospheric campaign of the Large-Scale Biosphere-Atmosphere Experiment in Amazonia (LBA) Program. The campaign, collocated with a Tropical Rainfall Measuring Mission (TRMM) satellite validation campaigns, was conducted in southwest Rondônia in January and February 1999 during the wet season. Highlights on the interaction between clouds, rain, and the underlying landscape through biospheric processes are presented and discussed.
In recent decades, global land use change has made a significant contribution to increasing green... more In recent decades, global land use change has made a significant contribution to increasing greenhouse gas levels and related climate change (Intergovernmental Panel on Climate Change 2007). This briefing outlines the Land Use, Land Use Change and Forestry (LULUCF) sector and its contribution to storing and releasing greenhouse gases in Scotland. It provides a brief introduction to what is included in the LULUCF sector, and the methods used to estimate emissions from these sources, and removals from the atmosphere.
The performance of the coupled oceanatmosphere component of the Brazilian Earth System Model vers... more The performance of the coupled oceanatmosphere component of the Brazilian Earth System Model version 2.5 (BESM-OA2.5) was evaluated in simulating the historical period 1850-2005. After a climate model validation procedure in which the main atmospheric and oceanic variabilities were evaluated against observed and reanalysis datasets, the evaluation specifically focused on the mean climate state and the most important large-scale climate variability patterns simulated in the historical run, which was forced by the observed greenhouse gas concentration. The most significant upgrades in the model's components are also briefly presented here. BESM-OA2.5 could reproduce the most important large-scale variabilities, particularly over the Atlantic Ocean (e.g., the North Atlantic Oscillation, the Atlantic Meridional Mode, and the Atlantic Meridional Overturning Circulation), and the extratropical modes that occur in both hemispheres. The model's ability to simulate such large-scale variabilities supports its usefulness for seasonal climate prediction and in climate change studies.
Understanding land use and land cover change necessitates documentation of past and current alter... more Understanding land use and land cover change necessitates documentation of past and current alterations in land cover in the Amazon Basin. LBA supports 19 projects that contribute to this understanding. Fourteen of these projects treat land use and land cover as a secondary topic to their focus on atmospheric sciences, hydrology, nutrient or carbon dynamics. Research in the remaining 5 projects focus solely on building their ability to predict both the location and magnitude of future changes to the Amazon region and seek to answer the following overarching questions: • What are the characteristics defining the diverse land uses present in Amazonia? • How is land use changing at various scales from local to global? • How can the land be used to provide a sustainable income for its research results and this perhaps presents, in itself, the greatest challenge for Earth System Science. Ultimately, in addition to augmenting our understanding of the importance of Amazonia for the planet, LBA must enhance the scientific understanding needed to guide the sustainable use of the Amazonian forests.
The Center for Weather Forecasting and Climate Studies-Center for Ocean-Land-Atmosphere Studies (... more The Center for Weather Forecasting and Climate Studies-Center for Ocean-Land-Atmosphere Studies (CPTEC-COLA) atmospheric general circulation model (AGCM) is integrated with nine initial conditions for 10 yr to obtain the model climate in an ensemble mode. The global climatological characteristics simulated by the model are compared with observational data, and emphasis is given to the Southern Hemisphere and South America. Evaluation of the model's performance is presented by showing systematic errors of several variables, and anomaly correlation and reproducibility are applied to precipitation. The model is able to simulate the main features of the global climate, and the results are consistent with analyses of other AGCMs. The seasonal cycle is reproduced well in all analyzed variables, and systematic errors occur at the same regions in different seasons. The Southern Hemisphere convergence zones are simulated reasonably well, although the model overestimates precipitation in the southern portions and underestimates it in the northern portions of these systems. The high-and low-level main circulation features such as the subtropical highs, subtropical jet streams, and storm tracks are depicted well by the model, albeit with different intensities from the reanalysis. The stationary waves of the Northern and Southern Hemispheres are weaker in the model; however, the dominant wavenumbers are similar to the observations. The energy budget analysis shows values of some radiative fluxes that are close to observations, but the unbalanced fluxes in the atmosphere and at the surface indicate that the radiation and cloud scheme parameterizations need to be improved. Besides these improvements, changes in the convection scheme and higher horizontal resolution to represent orographic effects better are being planned to improve the model's performance.
This study presents novel insight into the mechanisms of Atlantic Meridional Overturning Circulat... more This study presents novel insight into the mechanisms of Atlantic Meridional Overturning Circulation (AMOC) reduction and its recovery under a warmer climate scenario. An one-thousand-year-long numerical simulation of a global coupled ocean-ice-atmosphere climate model, subjected to a stationary atmospheric radiative forcing, depict a coherent picture of the Arctic sea ice melting as a trigger for the initial AMOC reduction, along with decreases in the northward fluxes of salt and heat. Further atmospheric-driven ocean processes contribute to an erosion of the stable stratification of the fresher, yet colder waters in the surface layers of the North Atlantic, contributing to the recovery of a permanently altered AMOC. The scientific scrutiny of the Atlantic Meridional Overturning Circulation (AMOC) as a driver of world climatic stability and change has sharply increased recently 1-7. Several studies based on both paleoclimatic data and model simulations concur in proposing mechanisms for AMOC reduction 8-11 or eventual collapse 12-16 in a warmer climate. According to the concept of the AMOC being driven by density gradients associated with deep-water formation in the North Atlantic (NATL) 17,18 , an eventual weakening of the AMOC can be seen as a direct result of the reduction of surface water density due to warming or salinity decreases of the upper ocean layers 1. Yet, the AMOC recovery has been suggested by several studies. The study 1 , for example, attributes the recovery to a northward transport of anomalous warmer water at depth, into the NATL region, that results in a destabilization of ocean stratification, restarting then the convection. The study 8 , on the other hand, suggest that the recovery is driven by ocean-only processes based on downward advection and mixing of freshwater by the still-active AMOC, that lead to an erosion of the stratification in the NATL, which generates convection. Here, we investigate the AMOC response to stationary atmospheric forcings, the pre-industrial (piControl) and the abrupt four times atmospheric CO 2 concentration increase (Abrupt4xCO2) of the CMIP5 protocol 19 , in an one-thousand-year-long numerical simulation of the Brazilian Earth System Model (BESM2.5) 20-23. This Abrupt4xCO2 stationary atmospheric forcing experimental design enables climate considerations of transient processes that act in the global climate system. The model, which demonstrated a bistable equilibria characteristic 2,24 (Supplementary Figure 1), underwent four phases; fast reduction, slow recovery, fast recovery, and damped oscillations, depicted in Fig. 1 and discussed below. The AMOC meridional mean profiles for control and perturbed conditions, the latter in the first and last 100 years of simulation, are shown in Fig. 2. AMOC weakening mechanisms Links between Arctic sea-ice loss and AMOC reduction have been pointed out by several studies. Consistent with the findings of previous studies 3,25-27 , the Abrupt4xCO2 BESM2.5 simulation predicts a time-evolving AMOC structure related to a concurrent decrease in Arctic sea ice volume and a reduced AMOC (Supplementary Fig. 2), which are components of a transient response (Fig. 1) to stationary atmospheric CO 2 perturbation.
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Papers by Carlos A Nobre