Evaluating Climate Variability and Coupling Strength of Land-atmosphere Interactions Across the Amazon Basin - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Evaluating Climate Variability and Coupling Strength of Land-atmosphere Interactions Across the Amazon Basin write by Nafiseh Haghtalab. This book was released on 2021. Evaluating Climate Variability and Coupling Strength of Land-atmosphere Interactions Across the Amazon Basin available in PDF, EPUB and Kindle. The Amazon basin, which contains about 60% of tropical rainforests in the world, plays vital roles in regulating climate patterns, sustaining ecosystem services, contributing to global biodiversity, and cycling nutrients. These services, however, have been disrupted by human activities within the region due to infrastructure development and resource extraction. These land-use changes have impacts from local to global scales, particularly on climate and hydrologic cycles, but the extent to which is unclear. Therefore, it is essential to examine precipitation variability and look for drivers of changes at multiple spatio-temporal scales. Analysis of hot spots of land-atmosphere interactions highlights the areas where changes in land surface characteristics influence the atmosphere behavior the most. This dissertation focuses on climate variability and land-atmosphere coupling across the Amazon basin. Research questions are addressed in three self-contained chapters. Chapter 2 examines the changes in precipitation amount and intensity using a high-resolution (0.05℗ʻ spatial resolution) gridded data set (CHIRPS) from 1982 to 2018. Several precipitation indices are developed to analyze trends using the Mann-Kendall test. Our results show landscape-scale changes in the timing and intensity of rainfall events. Specifically, wet areas of the western basin have become significantly wetter since 1982, with an increase of 182 mm of rainfall per year. In the eastern and southern regions, where deforestation is widespread, a significant drying trend is evident. In chapter 3, we aim to examine the impacts of potential tropical reforestation on surface energy and moisture budgets, including precipitation. We simulated changes in heat and moisture fluxes due to tropical reforestation using WRF.V3.9 (Weather Research and Forecast model) to analyze the sensitivity and magnitude of changes to the surface fluxes due to reforestation in the Amazon Basin. We found that the effects of reforestation on the atmosphere were more evident during the dry season; spatial patterns of the changes in atmospheric behavior due to reforestation were consistent with the pattern of land cover change, and the cooling effect of reforestation was evident at seasonal time scale. In chapter 4, following the results of chapter 3 on the effects of land surface characteristics on atmosphere behavior, we aim to find hot spots of strong land-atmosphere (L-A) coupling across the basin at regional scales. Strong land-atmosphere coupling is critical to understanding precipitation dynamics. Therefore, we applied two commonly used coupling approaches at the regional spatial scale and monthly temporal scale. Ultimately, we recommend a new metric considering more physical relationships, interactions, and lag times between variables. We found that the spatial pattern of hot spots is highly dependent on the temporal and spatial scales of analysis. Also, the interactions among variables within the boundary layer play a more important role in determining the hot spots of strong L-A coupling. Overall, the evidence provided here suggests that (1) precipitation distribution has changed over time (1982-2018) with wet areas getting wetter and dry areas getting drier across the Amazon basin; (2) reforestation of deforested regions across the basin moderates atmospheric patterns and behavior; (3) hot spots of strong L-A coupling are highly dependent on temporal and spatial scales of analysis as well as parameters interactions within the boundary layer.
Interactions Between Biosphere, Atmosphere and Human Land Use in the Amazon Basin
Interactions Between Biosphere, Atmosphere and Human Land Use in the Amazon Basin - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Interactions Between Biosphere, Atmosphere and Human Land Use in the Amazon Basin write by Laszlo Nagy. This book was released on 2016-11-09. Interactions Between Biosphere, Atmosphere and Human Land Use in the Amazon Basin available in PDF, EPUB and Kindle. This book offers a panorama of recent scientific achievements produced through the framework of the Large-Scale Biosphere-Atmosphere programme (LBA) and other research programmes in the Brazilian Amazon. The content is highly interdisciplinary, with an overarching aim to contribute to the understanding of the dynamic biophysical and societal/socio-economic structure and functioning of Amazonia as a regional entity and its regional and global climatic teleconnections. The target readership includes advanced undergraduate and post-graduate students and researchers seeking to untangle the gamut of interactions that the Amazon’s complex biophysical and social system represent.
Land - Atmosphere Coupling in Climate Models Over North America; Understanding Inter-model Differences
Land - Atmosphere Coupling in Climate Models Over North America; Understanding Inter-model Differences - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Land - Atmosphere Coupling in Climate Models Over North America; Understanding Inter-model Differences write by Almudena García García. This book was released on 2020. Land - Atmosphere Coupling in Climate Models Over North America; Understanding Inter-model Differences available in PDF, EPUB and Kindle. The interactions between the lower atmosphere and the land surface are associated with weather and climate phenomena such as the duration, frequency and intensity of extreme temperature and precipitation events. Thus, the representation of land- atmosphere interactions in climate model simulations is crucial for projecting future changes in the statistics of extreme events as realistically as possible. Given the importance of the land-atmosphere interaction, the purpose of the thesis is to evaluate climate simulations performed by General Circulation Models (GCMs) and Regional Climate Models (RCMs) and examine the role of the Land Surface Model (LSM) component and the horizontal resolution over North America. For this purpose, I analyze a large set of simulations from GCMs and RCMs used by the fifth assessment report of the Intergovernmental Panel on Climate Change (IPCC) as well as my own simulations performed by the Weather Research and Forecasting (WRF) model. Results show that GCM simulations present large uncertainties in the representation of land-atmosphere interactions in comparison with observations. This work also reveals a dependence of the simulated land-atmosphere interactions on the LSM components used in regional and global simulations. Additionally, the LSM component is identified as an important source of uncertainty in the simulation of extreme temperature and precipitation events. Increasing the horizontal resolution also affects the simulation of land-atmosphere interactions, which lead to the intensification of precipitation, evapotranspiration and soil moisture at low latitudes; that is increased latent heat flux, soil moisture, and precipitation. The impact of both factors, horizontal resolution and the LSM, is larger in summer in agreement with the summer intensification of land-atmosphere interactions reported in the literature. The comparison of model simulations and observations indicates that the use of the most comprehensive LSM component available in WRF, the Community Land Model version 4 (CLM4), leads to a better representation of temperature climatologies. In contrast, finer horizontal resolutions are associated with larger biases in the WRF simulation of precipitation climatology, due to the overestimation of precipitation in the WRF model. Due to the large effect of the LSM component on the simulation of near-surface conditions shown in this dissertation, the use of simple version of LSM component in GCMs, RCMs or reanalyses can be an important limitation in climate simulations and reanalysis products.
Vegetation, Water, Humans and the Climate
Vegetation, Water, Humans and the Climate - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Vegetation, Water, Humans and the Climate write by Pavel Kabat. This book was released on 2012-12-06. Vegetation, Water, Humans and the Climate available in PDF, EPUB and Kindle. A state-of-the-art overview of the influence of terrestrial vegetation and soils within the Earth system. The text deals especially with interactions between the terrestrial biosphere and the atmosphere via the hydrological cycle and their interlinkage with anthropogenic activities. Measurements gathered in integrated field experiments in the Sahel, the Amazon, North America and South-east Asia confirm the importance of these interactions. Observations are complemented by modelling studies, including regional models that simulate flows and transport in river catchments, coupled land-cover and regional climate systems, and Earth-system and global circulation models. Water, nutrient and sediment fluxes in river basins are also discussed and are shown to be highly impacted and regulated by humans through land use, pollution and river engineering. Finally, the book discusses environmental vulnerability and methodologies for assessing the risks associated with regional and global climatic and environmental variability and change. The results reported in this book are based on the research work of many individual scientists and teams around the world associated with the objectives of the IGBP-BAHC and WCRP-GEWEX international research programmes.
An Evaluation of the Strength of Land-atmosphere Coupling
An Evaluation of the Strength of Land-atmosphere Coupling - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook An Evaluation of the Strength of Land-atmosphere Coupling write by Paul A. Dirmeyer. This book was released on 2000. An Evaluation of the Strength of Land-atmosphere Coupling available in PDF, EPUB and Kindle.
