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CLIMATE MODELS Edited by Leonard M. Druyan Climate Models Edited by Leonard M. Druyan Published by InTech Janeza Trdine 9, 51000 Rijeka, Croatia Copyright © 2012 InTech All chapters are Open Access distributed under the Creative Commons Attribution 3.0 license, which allows users to download, copy and build upon published articles even for commercial purposes, as long as the author and publisher are properly credited, which ensures maximum dissemination and a wider impact of our publications. After this work has been published by InTech, authors have the right to republish it, in whole or part, in any publication of which they are the author, and to make other personal use of the work. Any republication, referencing or personal use of the work must explicitly identify the original source. As for readers, this license allows users to download, copy and build upon published chapters even for commercial purposes, as long as the author and publisher are properly credited, which ensures maximum dissemination and a wider impact of our publications. Notice Statements and opinions expressed in the chapters are these of the individual contributors and not necessarily those of the editors or publisher. No responsibility is accepted for the accuracy of information contained in the published chapters. The publisher assumes no responsibility for any damage or injury to persons or property arising out of the use of any materials, instructions, methods or ideas contained in the book. Publishing Process Manager Irena Voric Technical Editor Teodora Smiljanic Cover Designer InTech Design Team First published March, 2012 Printed in Croatia A free online edition of this book is available at www.intechopen.com Additional hard copies can be obtained from [email protected] Climate Models, Edited by Leonard M. Druyan p. cm. ISBN 978-953-51-0135-2 Contents Preface IX Part 1 Atmospheric Models 1 Chapter 1 Tropical Channel Model 3 Pallav Ray, Chidong Zhang, Jim Dudhia, Tim Li and Mitchell W. Moncrieff Chapter 2 Seasonal Climate Prediction and Predictability of Atmospheric Circulation 19 June-Yi Lee and Bin Wang Chapter 3 Regional Climate Model Applications for West Africa and the Tropical Eastern Atlantic 43 Leonard M. Druyan and Matthew Fulakeza Part 2 Hydrology and Extreme Climate Events 59 Chapter 4 Advances in Streamflow Prediction: A Multimodel Statistical Approach for Application on Water Resources Management 61 Sonia R. Gámiz-Fortis, María Jesús Esteban-Parra and Yolanda Castro-Díez Chapter 5 Impact of Global Climate Change on Regional Water Resources: A Case Study in the Huai River Basin 87 Ju Qin, Hao Zhen-chun, Ou Geng-xin, Wang Lu and Zhu Chang-jun Chapter 6 Nonparametric Statistical Downscaling of Precipitation from Global Climate Models 109 Paul Nyeko-Ogiramoi, Patrick Willems, Gaddi Ngirane-Katashaya and Victor Ntegeka VI Contents Chapter 7 Modeling Extreme Climate Events: Two Case Studies in Mexico 137 O. Rafael García-Cueto and Néstor Santillán-Soto Part 3 Ocean, Biosphere and Soil Interactions 161 Chapter 8 Numerical Investigation of the Interaction Between Land Surface Processes and Climate 163 Kazuo Mabuchi Chapter 9 Modeling Freezing and Thawing of Subsurface Soil Layers for Global Climate Models 209 Kazuyuki Saito Chapter 10 The Role of Stochastic Forcing in Climate Models: The Case of Thermohaline Circulation 231 M.N. Lorenzo, J.J. Taboada and I. Iglesias Part 4 Aerosols 247 Chapter 11 A Review of Modeling Approaches Accounting for Aerosol Impacts on Climate 249 Abhilash S. Panicker and Dong-In Lee Chapter 12 Aerosol Radiative Forcing: AERONET-Based Estimates 275 O.E. García, J.P. Díaz, F.J. Expósito, A.M. Díaz, O. Dubovik and Y. Derimian Chapter 13 Correcting Transport Errors During Advection of Aerosol and Cloud Moment Sequences in Eulerian Models 297 Robert McGraw Part 5 Modeling Climate Impacts 311 Chapter 14 The Effects of Climate Change on Orangutans: A Time Budget Model 313 Charlotte Carne, Stuart Semple and Julia Lehmann Preface ‘Climate models’ is a very broad topic, so a single volume can only offer a small sampling of relevant research activities. This volume of 14 chapters includes descriptions of a variety of modeling studies for a variety of geographic regions by an international roster of authors. The climate research community generally uses the rubric ‘climate models’ to refer to organized sets of computer instructions that produce simulations of climate evolution. The code is based on physical relationships that describe the shared variability of meteorological parameters such as temperature, humidity, precipitation rate, circulation, radiation fluxes, etc. Three-dimensional climate models are integrated over time in order to compute the temporal and spatial variations of these parameters. Model domains can be global or regional and the horizontal and vertical resolutions of the computational grid vary from model to model. Considering the entire climate system requires accounting for interactions between solar insolation, atmospheric, oceanic and continental processes, the latter including land hydrology and vegetation. Model simulations may concentrate on one or more of these components, but the most sophisticated models will estimate the mutual interactions of all of these environments. Advances in computer technology have prompted investments in more complex model configurations that consider more phenomena interactions than were possible with yesterday’s computers. However, not every attempt to add to the computational layers is rewarded by better model performance. Extensive research is required to test and document any advantages gained by greater sophistication in model formulation. One purpose for publishing climate model research results is to present purported advances for evaluation by the scientific community. While some versions of environmental simulation models are used for weather prediction, the appellation ‘climate models’ implies applications related to time-mean conditions. Seasonal climate forecasts and decadal climate change projections are challenging applications. Moreover, climate models are also profitably employed to evaluate the sensitivity of components of the climate system to environmental influences. For example, how are regional precipitation anomalies related to sea- surface temperature anomaly patterns? In a specific case, what impact does El Niño have on southeast US winter rainfall? X Preface The wide range of topics covered by Climate Models provides an introduction to some of the scientific themes of modern environmental research. Ray et al. introduce the innovative concept of the Tropical Channel Model (TCM), which is a compromise between a regional climate model and a GCM. The TCM domain is global in the zonal direction, but driven by a global data set at its northern and southern boundaries. Authors believe that it offers the advantage of quantifying the extra-tropical influences on the tropics. TCMs based on the MM5, WRF and ECHAM4 are presented. The MM5 TCM successfully initiates a Madden-Julian Oscillation (MJO) event two months after initialization, suggesting that this event is stimulated by extra-tropical influences. Lee and Wang present a study of the predictability of tropospheric circulation based on ensemble simulations of eight atmosphere-ocean-land coupled global climate models. The investigation is based on 9-15 member ensemble predictions per model of seasonal means with one month lead time. Seasonal mean geopotential height fields are validated against NCEP/DOE reanalysis data. The chapter discusses the efficacy of multiple model ensembles, approaches for computing signal to noise ratios and the limits of predictability. Much of the estimated predictability is attributable to transitions between ENSO phases, so predictability tends to be higher over the tropics than over higher latitudes. Druyan and Fulakeza introduce the concept of regional climate models, cousins to the global models, but which are integrated over limited geographical areas. Their usual advantage is a higher computational resolution that has the potential to elicit more spatial detail from simulations, such as in analyses of African easterly waves. The authors summarize some results from a history of regional climate model studies for West Africa and the neighboring Atlantic Ocean. The thorough evaluation of model performance for historical events is preliminary to its ultimate application for projections of decadal climate change in a warming world. Gámiz-Fortis et al. study streamflow variability and predictability of each of four river systems in the Iberian Peninsula. The approach accounts for the physical characteristics of the specific basins and exploits statistically significant correlations between river streamflow time series in each river basin and large-scale sea surface temperature (SST) variability from preceding seasons (as predictors). Results demonstrate a range of moderate to strong influence of Atlantic SST on streamflow. Authors suggest that the predictability of the streamflows at seasonal, inter-annual and decadal time scales will be useful for the management of the increasingly limited water resources in Portugal and Spain. Although the research is site-specific, its conceptual basis and lessons learned should be transferable to other areas of the world facing similar problems. Ju et al. describe the results of coupled GCM/hydrology modeling for the Huaihe River Basin in Eastern China. They are especially concerned with long-range projections that will inform about future frequencies of floods. Their dynamic hydrology model, driven by decadal GCM climate projections, simulates river flow Preface XI rates with greater spatial detail than possible with the GCM alone. The model output includes evapotranspiration, runoff generation, runoff dividing computations and flow routing. Runoff is divided into surface flow, subsurface flow and groundwater flow. Global Climate change projections are usually made at a spatial resolution that is too coarse for many applications. Nyeko-Ogiramoi et al. describe a method of downscaling rainfall time series to spatial scales relevant for hydrological climate change impacts at catchment level, including impacts on high and low flow extremes. Their statistical “quantile perturbation” downscaling technique assumes that relative changes in time series obtained from GCM simulations of the contemporary and future climate can be applied to the observed climate to obtain projections of the future climate. The technique is illustrated for outputs from a suite of GCMs targeting the Lake Victoria (Africa) catchments in the upper River Nile basin. García-Cueto and Santillán-Soto discuss projections of return frequencies of heat waves in Mexicali and floods in Villahermosa, two Mexico cities. Their modeling approach applies the statistics of extremes based on historical climate data. The analysis provides considerable insight into expected extremes of maximum surface temperature and precipitation rates. Since the analysis is based on contemporary and historical records, which reflect contemporary and historical climate forcing, its relevance for future greenhouse forcing is subject to interpretation. Mabuchi reviews the importance of interactions between land surface processes and climate. The chapter describes the structure of the biosphere-atmosphere interaction model (BAIM) and gives examples of its performance. Applications of the coupled models include assessing impacts of deforestation on climate and the responses of the biosphere to climate variability over seven sub-regions of Asia. The author suggests that the studies using the physical climate model coupled with the biological scheme are useful for improving our understanding of the physical and biological mechanisms in regional and global climate systems and for improving estimates for future scenarios. Saito shows results of land process modeling of freezing and thawing of subsurface soil layers, which is particularly relevant at high latitudes. Results are presented for offline simulations using several model configurations forced by atmospheric data. Each model version can also be incorporated into fully coupled climate models. Moderate skill is shown for simulations of the areal extent of seasonally frozen ground and permafrost, but the simulated inter-annual variability of active layer depth and river discharge is poor. The chapter offers important lessons on the sensitivity of results to model configuration, and it emphasizes the challenges arising from the sparsity of validation data. Nieves et al. describe climate simulations based on two simplified models of the climate system. The second is termed a model of "intermediate complexity" and it