Table Of ContentCLIMATE MODELS
Edited by Leonard M. Druyan
Climate Models
Edited by Leonard M. Druyan
Published by InTech
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First published March, 2012
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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
