Land Surface-atmosphere Interactions in Regional Modeling Over South America

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Release : 2005
Genre : Atmospheric circulation
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Land Surface-atmosphere Interactions in Regional Modeling Over South America - 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 Surface-atmosphere Interactions in Regional Modeling Over South America write by Luis Gustavo Goncalves de Goncalves. This book was released on 2005. Land Surface-atmosphere Interactions in Regional Modeling Over South America available in PDF, EPUB and Kindle.

Land Surface-atmosphere Interactions in Regional Modeling Over South America

Download Land Surface-atmosphere Interactions in Regional Modeling Over South America PDF Online Free

Author :
Release : 2005
Genre : Atmospheric circulation
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Land Surface-atmosphere Interactions in Regional Modeling Over South America - 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 Surface-atmosphere Interactions in Regional Modeling Over South America write by Luis Gustavo Goncalves de Goncalves. This book was released on 2005. Land Surface-atmosphere Interactions in Regional Modeling Over South America available in PDF, EPUB and Kindle.

Land Surface — Atmosphere Interactions for Climate Modeling

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Release : 2012-12-06
Genre : Science
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Book Rating : 551/5 ( reviews)

Land Surface — Atmosphere Interactions for Climate Modeling - 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 Surface — Atmosphere Interactions for Climate Modeling write by E.F. Wood. This book was released on 2012-12-06. Land Surface — Atmosphere Interactions for Climate Modeling available in PDF, EPUB and Kindle. It is well known that the interactions between land surfaces and the atmosphere, and the resulting exchanges in water and energy have a tremendous affect on climate. The inadequate representation of land-atmosphere interactions is a major weakness in current climate models, and is providing the motivation for the HAPEX and ISLSCP experiments as well as the proposed Global Energy and Water Experiment (GEWEX) and the Earth Observing System (EOS) mission. The inadequate representation reflects the recognition that the well-known phys ical relationships, which are well described at small scales, result in different relationships when represented at the scales used in climate models. Understanding this transition in the mathematical relationships with increased space-time scales appears to be very difficult, and has led to different approaches; at one extreme, the famous "bucket" model where the land-surface is a simple one layer storage without vegetation; the other extreme may be Seller's Simple Biosphere Model (Sib) where one big leaf covers the climate model grid. Given the heterogeneous nature of landforms, soils and vegetation within a climate model grid, the development of new land surface parameterizations, and their verification through large scale experiments is perceived to be a challenging area of research for the hydrology and meteorology communities. This book evolved from a workshop held at Princeton University to explore the status of land surface parameterizations within climate models, and how observa tional data can be used to assess these parameterizations and improve models.

Land - Atmosphere Coupling in Climate Models Over North America; Understanding Inter-model Differences

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Release : 2020
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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.

Land-atmosphere Interactions and Regional Climate in West Africa and South America

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Release : 2017
Genre : Electronic dissertations
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Land-atmosphere Interactions and Regional Climate in West Africa and South America - 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 Interactions and Regional Climate in West Africa and South America write by Amir Erfanian Javadian Entezar Yazd. This book was released on 2017. Land-atmosphere Interactions and Regional Climate in West Africa and South America available in PDF, EPUB and Kindle. Land, atmosphere, and oceans interact with each other through energy, mass, and momentum exchanges. These interactions regulate climate variability and influence climate changes at the regional scale. One notable example of highly influential land-atmosphere-ocean interactions on regional climates is monsoonal systems that influence a substantial portion of the world’s population. In this dissertation, the present and future climates of West Africa (WA) and South America (SA), two important monsoon regions, were studied utilizing Regional and Global Climate Models (RCMs and GCMs), mathematical techniques and data mining tools, and observational data (in-situ, remote-sensing, and reanalysis). The objective is to advance our understanding on the role of land-atmosphere-ocean feedbacks, especially vegetation-climate interactions, in the climate variability, change, and extremes over these regions. Special attention was given to the improvement of climate simulations and reliability of future climate projections by quantifying and/or reducing uncertainties from multiple sources. As part of this dissertation, two new approaches concerning regional climate modeling and projection were developed, each pertaining to one of the geographic domains. One is the Ensemble-based Reconstructed Forcings (ERF) method that faithfully reproduces the Multi-Model Ensemble (MME) mean but requires only a fraction of the computational cost of the conventional MME approach, which is critical for reducing the high uncertainties in the outlook of future precipitation change over WA. The other newly developed approach tackle the nesting practice, a major source of RCM bias that causes (large-scale) circulation in SA to drift away from that of the driving GCMs. To this end, a new paradigm of regional climate modeling was proposed that includes the influential oceans within the RCM domain to better resolve the large-scale circulation of the SA climate. Results from a fully coupled regional climate model, with and without dynamic vegetation, revealed significant influence of vegetation-climate interactions on the mean and variability of the surface hydroclimate of the two regions of focus. Precipitation, surface temperature, evapotranspiration, and soil moisture were all strongly influenced. In particular, results from both numerical experiments and observational data analysis indicated that tropical oceanic variability plays a dominant role in precipitation variability over SA, including the unprecedented extreme drought of 2016; in addition, greenhouse gas warming was found to significantly contribute to the amplification of the 2016 drought, especially during the pre-monsoon season. Natural vegetation dynamics improves the model performance in capturing the anomalies of surface water storage but has a negligible impact on precipitation anomalies of this extreme drought. Results of this research help advance our understanding and improve our capability to quantify and predict climate variability, change, and extremes over WA and SA.