Tropical deforestation causes local and regional changes in climate through complex biophysical a... more Tropical deforestation causes local and regional changes in climate through complex biophysical and biogeochemical processes. These processes must be accurately represented in Earth System models for reliable predictions of how future land-use change will impact climate. The impacts of tropical deforestation in the sixth Coupled Model Intercomparison Project (CMIP6) group of models have yet to be fully assessed and evaluated. Here, we use satellite observations to evaluate the local land-surface temperature and precipitation responses to tropical forest loss within CMIP6 simulations analysed at consistent spatial scales. Remote sensed observations show consistent local warming and drying responses to tropical forest loss across all analysed scales from 25 to 200 km. The multi-model mean broadly agrees with observations, although some models simulate increased rainfall and local cooling due to tropical deforestation, opposite to the observed response. We explore potential reasons for this discrepancy within the models. This work provides key insights for specific model improvement in relation to real-world observations.
Quarterly Journal of the Royal Meteorological Society
Tropical–extratropical cloud bands are common in South America (SAm), contributing significantly ... more Tropical–extratropical cloud bands are common in South America (SAm), contributing significantly to the total rainy season precipitation. Thus, it is fundamental that climate and weather forecast models correctly represent them and their associated dynamic aspects. Adopting an event‐based framework, we evaluate the performance of two global models in simulating the observed cloud bands over SAm: the Brazilian Global Atmospheric Model version 1.2 (BAM‐1.2) and the Hadley Centre Global Environment Model in the Global Coupled configuration 3.1 (HadGEM3‐GC3.1). Both models reproduce the main characteristics of cloud bands and the dynamical aspects leading to their development and persistence. Nonetheless, the biases in precipitation during simulated cloud bands contribute more than 50% of the bias in total precipitation in some regions. BAM‐1.2 simulates fewer but more persistent cloud bands than observed; HadGEM3‐GC3.1 simulates weaker cloud band activity during early summer and more p...
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.
Tropical deforestation causes local and regional changes in climate through complex biophysical a... more Tropical deforestation causes local and regional changes in climate through complex biophysical and biogeochemical processes. These processes must be accurately represented in Earth System models for reliable predictions of how future land-use change will impact climate. The impacts of tropical deforestation in the sixth Coupled Model Intercomparison Project (CMIP6) group of models have yet to be fully assessed and evaluated. Here, we use satellite observations to evaluate the local land-surface temperature and precipitation responses to tropical forest loss within CMIP6 simulations analysed at consistent spatial scales. Remote sensed observations show consistent local warming and drying responses to tropical forest loss across all analysed scales from 25 to 200 km. The multi-model mean broadly agrees with observations, although some models simulate increased rainfall and local cooling due to tropical deforestation, opposite to the observed response. We explore potential reasons for...
In this study, we evaluated the performance of the Brazilian Global Atmospheric Model (BAM), in i... more In this study, we evaluated the performance of the Brazilian Global Atmospheric Model (BAM), in its version 2.2.1, in the representation of the surface variables solar radiation, temperature (maximum, minimum, and average), and wind speed. Three experiments were carried out for the period from 2016 to 2022 under three different aerosol conditions (constant (CTE), climatological (CLIM), and equal to zero (ZERO)), discarding the first year as a spin-up period. The observations came from a high-resolution gridded analysis that provides Brazil with robust data based on observations from surface stations on a daily scale from 1961 to 2020; therefore, combining the BAM outputs with the observations, our intercomparison period took place from 2017 to 2020, for three timescales: daily, 10-day average, and monthly, targeting different applications. In its different simulations, BAM overestimated solar radiation throughout Brazil, especially in the Amazon; underestimated temperature in most o...
Paleoclimate simulations are generally performed using coarse global climate models. However, val... more Paleoclimate simulations are generally performed using coarse global climate models. However, validation of these simulations using a local dataset may be penalized by the coarse grid of the global models. Using a regional climate model, which benefits from the use of higher resolution in a limited area and specific period of time, may help improve the validation of the simulations and help to understand the climate of the past. The objective of this study is to evaluate the Mid-Holocene (MH) simulations for Brazil at 20 km spatial resolution using the regional Eta Model. The simulations are produced by nesting the Eta Model to the National Institute for Space Research (INPE) Global Spectral Atmospheric Model at T062 resolution and 28 vertical levels. Both global and regional models used the same orbital parameters to produce the Milankovic Cycles based on the Berger parameterization. The models adopted the typical carbon dioxide values for the present time and the MH. Downscaling s...
The Climate Science for Service Partnership Brazil (CSSP‐Brazil) project provides Brazil and UK p... more The Climate Science for Service Partnership Brazil (CSSP‐Brazil) project provides Brazil and UK partners the opportunity to address important challenges faced by the climate modeling community, including the need to develop subseasonal and seasonal prediction and climate projection services. This paper provides an overview of the climate modeling and prediction research conducted through CSSP‐Brazil within the context of a framework to advance climate prediction services in Brazil that includes a research‐to‐services (R2S) and a services‐to‐research (S2R) feedback pathway. The paper also highlights plans to advance scientific understanding and capability to produce beneficial climate knowledge and new products to improve climate prediction services to support decisions in various industries in Brazil. Policy‐relevant outcomes from climate modeling and prediction exercises illustrated in this paper include supporting stakeholders with climate information provided from weeks to months...
The objective of this study is to evaluate the 2 meter-temperature forecasts (T2m) and temperatur... more The objective of this study is to evaluate the 2 meter-temperature forecasts (T2m) and temperature in the first sigma-level (Tems) from the Center for Weather Prediction and Climate Studies, Atmospheric Global Circulation Model (CPTEC/AGCM) during 20th January to 8th February 2003. The CPTEC regional Eta model reanalysis were used for comparisons. We verified in the reanalysis wind fields a well characterized LLJ and in the T2m fields a relatively higher temperatures from Northern Bolivia to Northern Argentina during the period. In the 850 hPa 24-hour wind forecast it was verified that the AGCM predicted the SALLJ in the correct position, but it underestimated the maximum wind core intensity. The higher temperatures observed in northern Bolivia and Argentina were well captured by the model. However, the Tems overestimated the field temperature from reanalysis, while T2m agrees better with the reanalysis. The bias indicated that in the three first weeks the errors has not grown marke...
ABSTRACT The aim of the present work was to evaluate the 2-meter temperature, 2-meter specific hu... more ABSTRACT The aim of the present work was to evaluate the 2-meter temperature, 2-meter specific humidity and 10-meter wind (T2m and q2m, respectively) of the Atmosphere Global Circulation Model from the Center for Weather Prediction and Climate Studies (AGCM/CPTEC) over the South America (SA), during 1 st July to 31 July 2006. Comparisons between T2m, q2m and V10m forecasts were carried through and the respective variable of the AGCM/CPTEC from 1 st sigma level in order to verify if it had increase in the implementation of the new variables. It was computed statistical index to verify the performance of the model. The results indicated better performance of the new variables over globe and in a local analysis for Sao Paulo. On the other hand, it indicated one worse performance for regions of. SA. This fact can be associated to the methodology used for the surface fluxes calculation between the interface land-ocean.
. Turbulence parameterization scheme for planetary boundary layer (PBL) based on Taylor's sta... more . Turbulence parameterization scheme for planetary boundary layer (PBL) based on Taylor's statistical formulation for turbulent flow is used in the Brazilian Global Atmospheric Model (BAM). Taylor's approach has been already applied to mesoscale and air pollution atmospheric models, but it is the first time that this approach is employed in a global model. The BAM model is operationally used to generate numerical weather forecasting by the INPE (National Institute for Space Research – Brazil). The simulation performed with BAM model using Taylor's parameterization is compared with the results obtained with the schemes presented by Holtslag-Boville, Sungsu-Park, and Mellor-Yamada trying to reproduce the ERA5 reanalysis data of two different initial conditions of two different seasons (dry season and wet season). The obtained comparison exhibit a positive result for the new parameterization simulating global precipitation, cloud coverage, and top atmospheric thermal radiation, specially in the dry season. Positive results for the Amazon basin were also obtained.
Tropical deforestation causes local and regional changes in climate through complex biophysical a... more Tropical deforestation causes local and regional changes in climate through complex biophysical and biogeochemical processes. These processes must be accurately represented in Earth System models for reliable predictions of how future land-use change will impact climate. The impacts of tropical deforestation in the sixth Coupled Model Intercomparison Project (CMIP6) group of models have yet to be fully assessed and evaluated. Here, we use satellite observations to evaluate the local land-surface temperature and precipitation responses to tropical forest loss within CMIP6 simulations analysed at consistent spatial scales. Remote sensed observations show consistent local warming and drying responses to tropical forest loss across all analysed scales from 25 to 200 km. The multi-model mean broadly agrees with observations, although some models simulate increased rainfall and local cooling due to tropical deforestation, opposite to the observed response. We explore potential reasons for this discrepancy within the models. This work provides key insights for specific model improvement in relation to real-world observations.
Quarterly Journal of the Royal Meteorological Society
Tropical–extratropical cloud bands are common in South America (SAm), contributing significantly ... more Tropical–extratropical cloud bands are common in South America (SAm), contributing significantly to the total rainy season precipitation. Thus, it is fundamental that climate and weather forecast models correctly represent them and their associated dynamic aspects. Adopting an event‐based framework, we evaluate the performance of two global models in simulating the observed cloud bands over SAm: the Brazilian Global Atmospheric Model version 1.2 (BAM‐1.2) and the Hadley Centre Global Environment Model in the Global Coupled configuration 3.1 (HadGEM3‐GC3.1). Both models reproduce the main characteristics of cloud bands and the dynamical aspects leading to their development and persistence. Nonetheless, the biases in precipitation during simulated cloud bands contribute more than 50% of the bias in total precipitation in some regions. BAM‐1.2 simulates fewer but more persistent cloud bands than observed; HadGEM3‐GC3.1 simulates weaker cloud band activity during early summer and more p...
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.
Tropical deforestation causes local and regional changes in climate through complex biophysical a... more Tropical deforestation causes local and regional changes in climate through complex biophysical and biogeochemical processes. These processes must be accurately represented in Earth System models for reliable predictions of how future land-use change will impact climate. The impacts of tropical deforestation in the sixth Coupled Model Intercomparison Project (CMIP6) group of models have yet to be fully assessed and evaluated. Here, we use satellite observations to evaluate the local land-surface temperature and precipitation responses to tropical forest loss within CMIP6 simulations analysed at consistent spatial scales. Remote sensed observations show consistent local warming and drying responses to tropical forest loss across all analysed scales from 25 to 200 km. The multi-model mean broadly agrees with observations, although some models simulate increased rainfall and local cooling due to tropical deforestation, opposite to the observed response. We explore potential reasons for...
In this study, we evaluated the performance of the Brazilian Global Atmospheric Model (BAM), in i... more In this study, we evaluated the performance of the Brazilian Global Atmospheric Model (BAM), in its version 2.2.1, in the representation of the surface variables solar radiation, temperature (maximum, minimum, and average), and wind speed. Three experiments were carried out for the period from 2016 to 2022 under three different aerosol conditions (constant (CTE), climatological (CLIM), and equal to zero (ZERO)), discarding the first year as a spin-up period. The observations came from a high-resolution gridded analysis that provides Brazil with robust data based on observations from surface stations on a daily scale from 1961 to 2020; therefore, combining the BAM outputs with the observations, our intercomparison period took place from 2017 to 2020, for three timescales: daily, 10-day average, and monthly, targeting different applications. In its different simulations, BAM overestimated solar radiation throughout Brazil, especially in the Amazon; underestimated temperature in most o...
Paleoclimate simulations are generally performed using coarse global climate models. However, val... more Paleoclimate simulations are generally performed using coarse global climate models. However, validation of these simulations using a local dataset may be penalized by the coarse grid of the global models. Using a regional climate model, which benefits from the use of higher resolution in a limited area and specific period of time, may help improve the validation of the simulations and help to understand the climate of the past. The objective of this study is to evaluate the Mid-Holocene (MH) simulations for Brazil at 20 km spatial resolution using the regional Eta Model. The simulations are produced by nesting the Eta Model to the National Institute for Space Research (INPE) Global Spectral Atmospheric Model at T062 resolution and 28 vertical levels. Both global and regional models used the same orbital parameters to produce the Milankovic Cycles based on the Berger parameterization. The models adopted the typical carbon dioxide values for the present time and the MH. Downscaling s...
The Climate Science for Service Partnership Brazil (CSSP‐Brazil) project provides Brazil and UK p... more The Climate Science for Service Partnership Brazil (CSSP‐Brazil) project provides Brazil and UK partners the opportunity to address important challenges faced by the climate modeling community, including the need to develop subseasonal and seasonal prediction and climate projection services. This paper provides an overview of the climate modeling and prediction research conducted through CSSP‐Brazil within the context of a framework to advance climate prediction services in Brazil that includes a research‐to‐services (R2S) and a services‐to‐research (S2R) feedback pathway. The paper also highlights plans to advance scientific understanding and capability to produce beneficial climate knowledge and new products to improve climate prediction services to support decisions in various industries in Brazil. Policy‐relevant outcomes from climate modeling and prediction exercises illustrated in this paper include supporting stakeholders with climate information provided from weeks to months...
The objective of this study is to evaluate the 2 meter-temperature forecasts (T2m) and temperatur... more The objective of this study is to evaluate the 2 meter-temperature forecasts (T2m) and temperature in the first sigma-level (Tems) from the Center for Weather Prediction and Climate Studies, Atmospheric Global Circulation Model (CPTEC/AGCM) during 20th January to 8th February 2003. The CPTEC regional Eta model reanalysis were used for comparisons. We verified in the reanalysis wind fields a well characterized LLJ and in the T2m fields a relatively higher temperatures from Northern Bolivia to Northern Argentina during the period. In the 850 hPa 24-hour wind forecast it was verified that the AGCM predicted the SALLJ in the correct position, but it underestimated the maximum wind core intensity. The higher temperatures observed in northern Bolivia and Argentina were well captured by the model. However, the Tems overestimated the field temperature from reanalysis, while T2m agrees better with the reanalysis. The bias indicated that in the three first weeks the errors has not grown marke...
ABSTRACT The aim of the present work was to evaluate the 2-meter temperature, 2-meter specific hu... more ABSTRACT The aim of the present work was to evaluate the 2-meter temperature, 2-meter specific humidity and 10-meter wind (T2m and q2m, respectively) of the Atmosphere Global Circulation Model from the Center for Weather Prediction and Climate Studies (AGCM/CPTEC) over the South America (SA), during 1 st July to 31 July 2006. Comparisons between T2m, q2m and V10m forecasts were carried through and the respective variable of the AGCM/CPTEC from 1 st sigma level in order to verify if it had increase in the implementation of the new variables. It was computed statistical index to verify the performance of the model. The results indicated better performance of the new variables over globe and in a local analysis for Sao Paulo. On the other hand, it indicated one worse performance for regions of. SA. This fact can be associated to the methodology used for the surface fluxes calculation between the interface land-ocean.
. Turbulence parameterization scheme for planetary boundary layer (PBL) based on Taylor's sta... more . Turbulence parameterization scheme for planetary boundary layer (PBL) based on Taylor's statistical formulation for turbulent flow is used in the Brazilian Global Atmospheric Model (BAM). Taylor's approach has been already applied to mesoscale and air pollution atmospheric models, but it is the first time that this approach is employed in a global model. The BAM model is operationally used to generate numerical weather forecasting by the INPE (National Institute for Space Research – Brazil). The simulation performed with BAM model using Taylor's parameterization is compared with the results obtained with the schemes presented by Holtslag-Boville, Sungsu-Park, and Mellor-Yamada trying to reproduce the ERA5 reanalysis data of two different initial conditions of two different seasons (dry season and wet season). The obtained comparison exhibit a positive result for the new parameterization simulating global precipitation, cloud coverage, and top atmospheric thermal radiation, specially in the dry season. Positive results for the Amazon basin were also obtained.
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