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Spatial autocorrelation of tropical precipitation is examined by the application of Moran's I index to the 17-year CMAP data set. Global I indices, which express the overall spatial autocorrelation of precipitation for the entire tropics, have an annual cycle characterized by bimodalism. A higher degree of spatial organization of tropical precipitation occurs during both boreal and austral summers. While the annual cycle of mean precipitation appears to be more unimodal, global I indices, therefore, provide an alternative definition of precipitation seasonality in the tropics. The seasonal variations in global I indices are small in the equatorial region, but are very large in subtropical latitudes. Local I indices which specify the spatial autocorrelation of precipitation in a small geographical area are also calculated at each individual grid cell using a moving window approach. Generally, high local I indices are associated with large precipitation gradients and low local I indices are related to areas of precipitation maxima or minima. Due to this unique property, local I indices are very useful in the identification of the core locations of large scale convective features such as the ITCZ and SPCZ. The interannual variations of tropical precipitation and associated spatial autocorrelation are affected by ENSO-related atmospheric/oceanic forcings. Changes in the local spatial autocorrelation of tropical precipitation during an ENSO event are induced by the shifting of convective centers (change of local precipitation) and the corresponding increase or decrease of the precipitation gradient for a location. Regions where precipitation variables are affected by ENSO include most of the tropical Pacific, Indonesia, Amazonia, Northeast Brazil and West Africa. These ENSO-related connections are strongest in DJF, when the SOI leads the precipitation variable and weakest in JJA, when the precipitation variables lead the SOI. Due to this relationship, JJA precipitation s

by Siu, Wai Lok., Thesis (M.Phil.)--Chinese University of Hong Kong, 1994., Includes bibliographical references (leaves 213-218)., p.i -ii, ACKNOWLEDGEMENTS --- p.iii, TABLE OF CONTENTS --- p.iv -vi, LIST OF FIGURES --- p.vi -viii, LIST OF PLATES --- p.ix, LIST OF TABLES --- p.x -xii, Chapter CHAPTER I --- INTRODUCTION --- p.1, Chapter 1.1 --- Problem Statement --- p.1, Chapter 1.2 --- Study Area --- p.3, Chapter 1.3 --- Research Objectives --- p.4, Chapter 1.4 --- Rationale --- p.9, Chapter 1.5 --- Organization of the Thesis --- p.10, Chapter CHAPTER II --- LITERATURE REVIEW --- p.12, Chapter 2.1 --- Introduction --- p.12, Chapter 2.2 --- Optical Properties of Sea Water --- p.12, Chapter 2.3 --- Water Quality Modeling Algorithms --- p.18, Chapter 2.3.1 --- Suspended Sediment Models --- p.22, Chapter 2.3.2 --- Chlorophyll Models --- p.29, Chapter 2.3.3 --- Sea Surface Temperature Models --- p.30, Chapter 2.3.4 --- Salinity Models --- p.33, Chapter 2.3.5 --- Total Phosphorus Models --- p.34, Chapter 2.4 --- Use of Chromaticity Technique --- p.35, Chapter 2.5 --- Principal Component Transformation --- p.37, Chapter 2.6 --- Remote Sensing Water Quality in Hong Kong --- p.37, Chapter 2.7 --- Summary --- p.38, Chapter CHAPTER III --- METHODOLOGY --- p.40, Chapter 3.1 --- Data Set --- p.40, Chapter 3.1.1 --- Water Sampling and Water Quality Parameters --- p.40, Chapter 3.1.2 --- Satellite Data --- p.45, Chapter 3.1.2.1 --- Image Preprocessing --- p.45, Chapter 3.1.2.1.1 --- Radiometric Correction --- p.45, Chapter 3.1.2.1.2 --- Atmospheric Correction --- p.49, Chapter 3.1.2.1.3 --- Geometirc Correction --- p.53, Chapter 3.1.2.2 --- Data Extraction --- p.55, Chapter 3.1.2.3 --- Spectral Data Transformation --- p.56, Chapter 3.2 --- Statistical Water Quality Models --- p.59, Chapter 3.3 --- Water Quality Mapping --- p.61, Chapter CHAPTER IV --- EXPERIMENTAL SET-UP --- p.63, Chapter 4.1 --- Introduction --- p.63, Chapter 4.2 --- Water Quality Samples --- p.63, Chapter 4.2.1 --- Sample Data for TM Experiment --- p.63, Chapter 4.2.2 --- Sample Data for SPOT Experiment --- p.68, Chapter 4.2.3 --- Correlations Among Parameters --- p.76, Chapter 4.3 --- Image Preprocessing --- p.81, Chapter 4.3.1 --- Image Destriping --- p.83, Chapter 4.3.2 --- Atmospheric Correction --- p.85, Chapter 4.3.3 --- Geometric Correction --- p.88, Chapter 4.4 --- Data Extraction --- p.89, Chapter 4.4.1 --- Descriptive Statistics of the Spectral Data Samples --- p.89, Chapter 4.4.2 --- Data Transformation --- p.100, Chapter 4.4.3 --- Correlations Among Spectral Variables --- p.103, Chapter 4.5 --- Summary --- p.107, Chapter CHAPTER V --- ANALYSIS OF WATER QUALITY MODELS …… --- p.113, Chapter 5.1 --- Introduction --- p.113, Chapter 5.2 --- Criteria for Assessing Water Quality Models --- p.113, Chapter 5.3 --- Models Derived from TM Data --- p.116, Chapter 5.3.1 --- Models of Various Water Quality Paramters --- p.116, Chapter 5.3.2 --- Summary --- p.142, Chapter 5.4 --- Models Derived from SPOT Data --- p.145, Chapter 5.4.1 --- Models of Various Water Quality Parameters --- p.145, Chapter 5.4.2 --- Summary --- p.169, Chapter 5.5 --- Comparisons Among Models --- p.171, Chapter 5.5.1 --- Comparisons Among Models Derived from TM and SPOT Data --- p.171, Chapter 5.5.2 --- Comparisons with Past Models --- p.172, Chapter 5.6 --- Conclusion --- p.173, Chapter CHAPTER VI --- WATER QUALITY MAPPING --- p.175, Chapter 6.1 --- Introduction --- p.175, Chapter 6.2 --- Classification Schemes for Various Water Quality Paramters --- p.175, Chapter 6.3 --- Water Quality Maps --- p.180, Chapter 6.3.1 --- Water Quality Mapping Using TM Data --- p.180, Chapter 6.3.2 --- Water Quality Mapping Using SPOT Data --- p.190, Chapter 6.4 --- Difficulties Encountered in Water Quality Mapping --- p.202, Chapter 6.5 --- Summary --- p.204, Chapter CHAPTER VII --- CONCLUSION --- p.206, Chapter 7.1 --- Summary of Findings --- p.206, Chapter 7.1.1 --- Summary on Water Quality Modeling --- p.206, Chapter 7.1.2 --- Summary on Water Quality Mapping --- p.208, Chapter 7.2 --- Limitations of the Study --- p.209, Chapter 7.3 --- Recommendations for Further Studies --- p.210, BIBLIOGRAPHY --- p.213, http://library.cuhk.edu.hk/record=b5887294, Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/)