ALBERT

Note: Contents: Preface. - 1 Introduction to the atmosphere. - Weather and climate. - Atmospheric hazards: assault by the elements. - The atmosphere: a part of the earth system. - Earth's four spheres. - Earth's spheres interact. - The carbon cycle. - Composition of the atmosphere. - Major components. - Carbon dioxide. - Variable components. - Ozone depletion - a global issue. - The ozone hole. - Effects of ozone depletion. - Montreal Protocol. - Probing the atmosphere. - Height and structure of the atmosphere. - Pressure changes. - Temperature changes. - Vertical variations in composition. - The ionosphere. - 2 Heating Earth's Surface and Atmosphere. - Earth-Sun Relationships. - Earth's Motions. - The Seasons. - Earth's Orientation. - Solstices and Equinoxes. - Energy, Heat, and Temperature. - Types of Energy. - Heat Energy Versus Temperature. - Mechanisms of Energy Transfer. - Conduction. - Convection. - Radiation. - Laws of Radiation. - The Fate of Incoming Solar Radiation. - Reflection and Scattering. - Absorption by Earth's Surface and Atmosphere. - Radiation Emitted by Earth. - Heating the Atmosphere. - The "Greenhouse Effect". - Role of Clouds in Heating Earth. - Heat Budget. - Latitudinal Heat Balance. - 3 Temperature. - For the Record: Air Temperature Data. - Why Temperatures Vary: The Controls of Temperature. - Land and Water. - Ocean Currents. - Altitude. - Geographic Position. - Cloud Cover and Albedo. - World Distribution of Temperatures. - Cycles of Air Temperature. - Daily Temperature Variations. - Magnitude of Daily Temperature Changes. - Annual Temperature Variations. - Temperature Measurement. - Mechanical Thermometers. - Electrical Thermometers. - Instrument Shelters. - Temperature Scales. - Applications of Temperature Data. - Heating Degree-Days. - Cooling Degree-Days. - Growing Degree-Days. - Temperature and Comfort. - 4 Moisture and Atmospheric Stability. - Movement of Water Through the Atmosphere. - Water's Changes of State. - Water in the Atmosphere. - Vapor Pressure and Saturation. - Relative Humidity. - How Relative Humidity Changes. - Natural Change in Relative Humidity. - Dew Point Temperature. - Humidity Measurement. - Adiabatic Temperature Changes. - Adiabatic Cooling and Condensation. - Lifting Processes. - Orographic Lifting. - Frontal Wedging. - Convergence. - Localized Convective Lifting. - Contents. - The Critical Weathermaker: Atmospheric Stability. - Types of Stability. - Stability and Daily Weather. - How Stability Changes. - Temperature Changes and Stability. - Vertical Air Movement and Stability. - 5 Forms of Condensation and Precipitation. - Condensation. - Condensation Aloft and Cloud Formation. - Clouds. - Cloud Classification. - Cloud Descriptions. - Fog. - Fogs Formed by Cooling. - Fogs Formed by Evaporation. - Dew and Frost. - How Precipitation Forms. - Precipitation from Cold Clouds: The Bergeron Process. - Precipitation from Warm Clouds: The Collision-Coalescence Process. - Forms of Precipitation. - Rain. - Snow. - Sleet and Glaze. - Hail. - Rime. - Precipitation Measurement. - Standard Instruments. - Measuring Snowfall. - Measurement Errors. - Precipitation Measurement by Weather Radar. - Intentional Weather Modification. - Cloud Seeding. - Fog and Cloud Dispersal. - Hail Suppression. - Frost Prevention. - Inadvertent Weather Modification: Urban-Induced Precipitation. - 6 Air Pressure and Winds. - Understanding Air Pressure. - Measuring Air Pressure. - Factors Affecting Air Pressure. - Pressure Changes With Altitude. - Factors Affecting Wind. - Pressure-Gradient Force. - Coriolis Force. - Friction. - Winds Aloft and Geostrophic Flow. - Curved Flow and the Gradient Wind. - Surface Winds. - How Winds Generate Vettical Air Motion. - Vertical Airflow Associated with Cyclones and Anticyclones. - Factors That Promote Vertical Airflow. - Wind Measurement. - 7 Circulation of the Atmosphere. - Scales of Atmospheric Motion. - Large- and Small-Scale Circulation. - Structure of Wind Patterns. - Local Winds. - Land and Sea Breezes. - Mountain and Valley Breezes. - Chinook (Foehn) Winds. - Katabatic (Fall) Winds. - Country Breeze. - Global Circulation. - Single-Cell Circulation Model. - Three-Cell Circulation Model. - Observed Distribution of Pressure and Winds. - Idealized Zonal Pressure Belts. - Semipermanent Pressure Systems: The Real World. - Monsoons. - The Asian Monsoon. - The North American Monsoon. - The Westerlies. - Why Westerlies?. - Jet Streams. - Origin of the Midlatitude Jet Stream. - Subtropical Jet Stream. - Waves in the Westerlies. - Westerlies and Earth's Heat Budget. - Global Winds and Ocean Currents. - The Importance of Ocean Currents. - Ocean Currents and Upwelling. - El Niño and La Niña. - Global Distribution of Precipitation. - Zonal Distribution of Precipitation. - Distribution of Precipitation Over the Continents. - Precipitation Regimes on a Hypothetical Continent. - 8 Air Masses. - What Is an Air Mass?. - Source Regions. - Classifying Air Masses. - Air-Mass Modification. - Properties of North American Air Masses. - Continental Polar (cP) and Continental Arctic (cA) Air Masses. - Lake-Effect Snow: Cold Air Over Warm Water. - Maritime Polar (mP) Air Masses. - Maritime Tropical (mT) Air Masses. - Continental Tropical (eT) Air Masses. - 9 Weather Patterns. - Polar-Front Theory. - Fronts. - Warm Fronts. - Cold Fronts. - Stationary Fronts. - Occluded Fronts. - Drylines. - Life Cycle of a Midlatitude Cyclone. - Formation: The Clash of Two Air Masses. - Development of Cyclonic Flow. - Occlusion: The Beginning of the End. - Idealized Weather of a Midlatitude Cyclone. - Cyclogenesis. - Cyclonic and Anticyclonic Circulation. - Divergence and Convergence Aloft. - Traveling Cyclones. - Patterns of Movement. - Anticyclonic Weather and Blocking Highs. - Case Study of a Midlatitude Cyclone. - Violent Spring Weather. - Weather in Peoria. - 10 Thunderstorms and Tornadoes. - What's in a Name?. - Thunderstorms. - Air-Mass Thunderstorms. - Stages of Development. - Occurrence. - Severe Thunderstorms. - Supercell Thunderstorms. - Squall Lines and Mesoscale Convective Complexes. - Lightning and Thunder. - What Causes Lightning?. - The Lightning Stroke. - Thunder. - Tornadoes. - The Development and Occurrence of Tornadoes. - Tornado Development. - Tornado Climatology. - Profile of a Tornado. - Tornado Destruction. - Tornado Forecasting. - Tornado Watches and Warnings. - Doppler Radar. - 11 Hurricanes. - Profile of a Hurricane. - Hurricane Formation and Decay. - Hurricane Formation. - Hurricane Decay. - Hurricane Destruction . - Storm Surge. - Wind Damage. - Inland Flooding. - Detecting and Tracking Hurricanes. - The Role of Satellites. - Aircraft Reconnaissance. - Radar and Data Buoys. - Hurricane Watches and Warnings. - 12 Weather Analysis and Forecasting. - The Weather Business: A Brief Overview. - Weather Analysis. - Gathering Data. - Weather Maps: Pictures of the Atmosphere. - Weather Forecasting. - Synoptic Weather Forecasting. - Numerical Weather Prediction. - Statistical Methods. - Techniques Used in Short-Range Forecasting. - Long-Range Forecasts. - Forecast Accuracy. - Tools in Weather Forecasting. - Satellites in Weather Forecasting. - What Weather Satellites Reveal. - Measurement by Satellite. - Weather Forecasting and Upper-Level Flow. - The Winter of 1977. - 13 Air Pollution. - A Brief Historical Perspective. - Air Pollution: Not a new Problem. - Some Historic Episodes. - Sources and Types of Air Pollution. - Primary Pollutants. - Secondary Pollutants. - Trends in Air Quality. - Meteorological Factors Affecting Air Pollution. - Wind as a Factor. - The Role of Atmospheric Stability. - Acid Precipitation. - Extent and Potency of Acid Precip

Note: Contents: Foreword. - Series Preface. - Preface to the Second Edition. - Preface to the First Edition. - Part 1 Introduction. - 1 Modeling Dynamic Systems. - 1.1 Model Components. - 1.2 Dynamic Modeling as a Skill and Art. - 1.3 Modeling in STELLA. - 1.4 Principles of Modeling. - Part 2 Some General Methods for Modeling. - 2 Four-Model Set. - 2.1 Stimulus-Response Model. - 2.2 Self-Referencing Model. - 2.3 Goal-Seeking Model. - 2.4 Goal-Setting Model. - 2.5 Examples. - 2.5.1 Exponential Decay of a Stock. - 2.5.2 Newtonian Cooling. - 3 Gradual Development of a Dynamic Model. - 3.1 Modeling Industrialization for a Simple Agrarian Society. - 3.2 Impacts of Per Capita Food Consumption on Population Growth. - 3.3 Adding Agriculture. - 3.4 Adding Industry. - 4 Two Independent Variables. - 4.1 Population Cohorts. - 4.1.1 Basic Cohort Model. - 4.1.2 Population Cohort Array. - 4.1.3 U.S. Population Growth. - 4.2 River Toxins. - 5 Randomness. - 5.1 Flipping a Coin. - 5.2 Intoxication Model. - 6 Positive and Negative Feedback. - 6.1 The Basic Model. - 6.2 Positive Feedback with Fixed Points. - 6.3 Elaborations. - 7 Derivatives and Lags. - 7.1 Introduction. - 7.2 Applications of Derivatives and Lags. - 7.2.1 Simple Population Model. - 7.2.2 Two-Population Model. - Part 3 Chemistry Models. - 8 The Law of Mass Action. - 8.1 Breakdown of Nitrogen Dioxide into Nitrogen Oxide and Oxygen. - 8.2 Stratospheric Ozone Depletion. - 9 Chance-Cleland Model for Enzyme-Substrate Interaction. - 10 The Olsen Oscillator. - Part 4 Genetics Models. - 11 Mating of Alleles. - 11.1 Heterozygosity and Disease Resistance. - 11.2 The Mating of Two Alleles into a Genotype: Proving the Hardy-Weinberg Law. - 12 Natural Selection and Mutation. - 13 Artificial Worms. - Part 5 Ecological Models. - 14 Robin Population. - 15 Two-Stage Insect Model. - 16 The Zebra Mussel. - 17 Single Cell Forest. - 18 Predator-Prey Models. - 18.1 Basic Model of Predator-Prey Interactions. - 18.2 Spatial Predator-Prey Model. - 19 Epidemic Modeling. - 20 Reestablishment of Wolves. - 21 Lyme Disease. - 22 Tragedy of the Commons. - Part 6 Economic Models. - 23 Introduction to Modeling Economic Processes. - 24 The Competitive Firm. - 25 The Monopolistic Firm. - 25.1 Basic Model. - 25.2 Taxing Monopolies. - 26 Competitive Equilibrium. - 27 Substitution. - 27.1 Isoquants. - 27.2 Finding the Profit-Maximizing Output Level and Input Combinations. - 28 Time Value. - 29 Opportunity Cost. - 30 Optimal Tree Cutting. - 31 Fisheries Reserve Model. - 32 Dynamic Scarcity. - 32.1 Competitive Scarcity. - 32.2 Monopoly Scarcity. - 33 Market Game. - 34 Pig Cycle. - Part 7 Engineering Models. - 35 The Assembly Line. - 35.1 Basic Model. - 35.2 Car Assembly Line. - 36 Models of Gravity and Acceleration. - 36.1 Falling Rock. - 36.2 Projectile Motion. - 36.3 Mass-Damper-Spring. - 36.4 Mechanical Amplifier. - 37 Chaos. - 37.1 A New Paradigm. - 37.2 Jenson Chaos. - 37.3 Lorenz Chaos. - 37.4 Two-Well Chaos. - Part 8 Conclusion. - 38 Beginning a Dialog. - Appendixes. - A1 System Requirements. - A1.1 Macintosh. - A1.2 Windows. - A2 Quick Help Guide. - A2.1 Overview of the STELLA(r) Operating Environment. - A2.2 Drawing an Inflow to a Stock. - A2.3 Drawing an Outflow from a Stock. - A2.4 Replacing a Cloud with a Stock. - A2.5 Bending Flow Pipes. - A2.6 Repositioning Flow Pipes. - A2.7 Reversing Direction of a Flow. - A2.8 Flow Define Dialog-Builtins. - A2.9 Moving Variable Names. - A2.10 Drawing Connectors. - A2.11 Defining Graphs and Tables. - A2.12 Dynamite Operations on Graphs and Tables. - References. - Index.

Note: Contents Foreword Preface Summary for Policymakers Synthesis Report Question 1 Question 2 Question 3 Question 4 Question 5 Question 6 Question 7 Question 8 Question 9 Working Group Summaries Working Group I: The Scientific Basis Working Group II: Impacts, Adaptation, and Vulnerability Working Group III: Mitigation Annexes A. Authors and Expert Reviewers B. Glossary of Terms C. Acronyms, Abbreviations, and Units D. Scientific, Technical, and Socio-Economic Questions Selected by the Panel E. List of Major IPCC Reports

Note: Table of contents List of contributors Preface A global vegetation index for SeaWiFS: Design and applications / N. Gobron, F, Melin, B. Pinty, M. M. Verstraete, J.-L. Widlowski and G. Bucini Modeling sensible heat flux using estimates of soil and vegetation temperatures: the HEIFE and IMGRASS experiments / Li Jia, Massimo Menenti, Zhongbo Su, Zhao-Liang Li, Vera Djepa and Jiemin Wang Exploitation of Surface Albedo Derived from the Meteosat Data to Characterize Land Surface Changes / Bernard Pinty, Michel M. Verstraete, Nadine Gobron, Fausto Roveda, Yves Govaerts, John V. Martonchik,David J. Diner and Ralph A. Kahn Towards a Climatology of Australian Land Surface Albedo for use in Climate Models / Ian F. Grant Collocated surface and satellite observations as constraints for Earth radiation budget simulations with global climate models / Martin Wild How well do aerosol retrievals from satellites and representation in global circulation models match ground-based AERONET aerosol statistics? / S. Kinne, B. Holben, T. Eck, A. Smirnov, O. Dubovik, I. Slutsker, D. Tanre, G. Zibozdi, U. Lohmann, S. Ghan, R. Easter, M. Chin, P. Ginoux, T. Takemura, I, Tegen, D. Koch, R. Kahn, E. Vermote, L. Stowe, O. Torres, M. Mishchenko, I. Geogdzhayev and A. Hiragushi Remote Sensing of Snow and Characterization of Snow Albedo for Climate Simulations / Anne W. Nolin and Allan Frei Using the Special Sensor Microwave Imager to Monitor Surface Wetness and Temperature / Alan Basist and Claude Williams Snow Cover Fraction in a General Circulation Model / A. Roesch, M. Wild and A. Ohmura Boreal Forest Fire Regimes and Climate Change / B.J. Stocks, B.M. Wotton, M.D. Flannigan, M.A. Fosberg, D.R. Cahoon and J.G. Goldammer Specification of surface characteristics for use in a high resolution regional climate model: on the role of glaciers in the Swiss alps / Stéphane Goyette, Claude Collet and Martin Beniston Using Satellite Data Assimilation to Infer Global Soil Moisture Status and Vegetation Feedback to Climate / Wolfgang Knorr and Jan-Peter Schulz The Use of Remotely-sensed Data for the Estimation of Energy Balance Components in a Mountainous Catchment Area / P.A. Brivio, R. Colombo and M. Meroni Integration of operationally available remote sensing and synoptic data for surface energy balance modelling and environmental applications on the regional scale / Stefan Niemeyer and Jürgen Vogt

Note: Contents List of Contributors Preface Acknowledgments List of Notations PART A. BEACH SYSTEMS: DEFINITION AND GLOBAL PERSPECTIVE 1 Beaches / Andrew D. Short 1.1 Introduction 1.2 Two-dimensional beaches 1.3 Three-dimensional beaches 1.4 Beach components and boundary conditions 1.5 Beach classifications 1.6 Beach Quantification 1.7 Beach morphodynamics 1.8 The study of beaches 1.9 Rationale for beach studies in the 21st century 2 Global variation in beach systems / Andrew D. Short 2.1 Global variation in beach systems 2.2 Coastal boundaries 2.3 Global climates 2.4 Global coastal sediments 2.5 Beach sediments 2.6 Global wave climates 2.7 Global and coastal tide regimes 2.8 Summary PART B. BEACH MORPHODYNAMICS 3 The shoreface / Peter J. Cowell, David J. Hanslow and Justin F. Meleo 3.1 Introduction: definition and significance 3.2 Morphological scale 3.3 Morphodynamics and shoreface equilibrium 3.4 Morphodynamic time scale and external controls 3.5 Summary 4 The surf zone / Troels Aagaard and Gerhard Masselink 4.1 Introduction 4.2 Wave transformation and wave set-up 4.3 Infragravity wave motion in the surf zone 4.4 Surf zone currents 4.5 Sediment transport 4.6 Bar morphology 5 The beachface / Michael Hughes and Ian Turner 5.1 Introduction 5.2 Swash kinematics 5.3 Beachface slope 5.4 Berms 5.5 Beach step 5.6 Swash cusps 5.7 Concluding remarks 6 The beach backshore and beyond / Patrick A. Hesp 6.1 Introduction 6.2 Backshore beach morphology 6.3 Backshore sand transport 6.4 Backshore aerodynamics 6.5 Beach- Backshore - dune sediment transport 6.6 Impact of salt aerosols 6.7 Overwash processes and deposits 6.8 Swash-deposited backshore landforms 6.9 Backshore dunes 6.10 Erosional and transgressive dunes 6.11 Summary PART C. BEACH TYPES AND APPLICATIONS 7 Wave-dominated beaches / Andrew D. Short 7.1 Introduction 7.2 Historical perspective 7.3 Wave-dominated beach types 7.4 Sequential beach changes 7.5 Multi-bar micro-tidal beaches 7.6 Beach 'state' curves: beaches in time and space 8 The effect of tides on beach morphodynamics / Gerhard Masselink and Ian L. Turner 8.1 Introduction 8.2 Tide-induced migration of hydrodynamic processes 8.3 Tide-induced fluctuations of the beach ground water table 8.4 Morphological response to tides 8.5 The parameterisation of tidal effects 8.6 A morphodynamic classification of tidal beaches 8.7 Summary 9 Embayed and structurally controlled beaches / Andrew D. Short and Gerhard Masselink 9.1 Introduction 9.2 Beach planform 9.3 Beach morphodynamics 9.4 Beach rotation 9.5 Headland sand bypassing 9.6 Structural impacts 9.7 Summary PART D. BEACH SYSTEMS AND IMPACTS 10 Beach Modification: natural impacts on beach morphodynamics / Andrew D. Short 10.1 Introduction 10.2 Determining beach type, circulation and bar number 10.3 Modification by cold climates 10.4 Modification by tropical climates 10.5 Modification of beach parameters 10.6 Summary 11 Beach ecology / Andrew D. Short and Patrick A. Hesp 11.1 Introduction 11.2 Beach habitats 11.3 Beach organisms 11.4 The beach energy system 11.5 Beach ecology and beach systems 11.6 Physical implication 11.7 Summary 12 Beach and dune stratification / Andrew D. Short and Patrick A. Hesp 12.1 Introduction 12.2 Boundary layer processes 12.3 Beach type and stratification 12.4 Dune stratification 12.5 Summary 13 Beach hazards and safety / Andrew D. Short 13.1 Introduction 13.2 Beach hazards 13.3 Wave-dominated beach hazards 13.4 Tide-modified beach hazards 13.5 Beach hazard rating 13.6 Applications to beach management 13.7 Summary PART E. LARGE SCALE BEACH BEHAVIOUR 14 Barrier morphodynamics / Patrick A. Hesp and Andrew D. Short 14.1 Introduction 14.2 The origin of barriers 14.3 Factors contributing to barrier type and evolution 14.4 Barrier morphodynamics and types 14.5 Controls on barrier evolution 14.6 Conclusion References Author Index Location index Subject Index

Note: Contents INTRODUCTION Objectives of the Investigations / FRANZ TESSENSOHN ARCHITECTURE OF THE FOLD-AND-THRUST BELT Northern Segment Explanatory Notes to the Geological Map of Brøggerhalvøya and Blomstrandhalvøya 1 : 40,000 / FRIEDHELM THIEDIG, KERSTIN SAALMANN & KARSTEN PIEPJOHN Nappe Stacking on Brøggerhalvøya, NW Spitsbergen / KARSTEN PIEPJOHN, FRIEDHELM THIEDIG & GEOFF M. MANBY Foreland-Thrust Belt Relationships SE of Kongsfjorden and the Function of the Pretender Fault / FRANZ TESSENSOHN, KARSTEN PIEPJOHN & FRIEDHELM THIEDIG Emergence of Basement-Dominated Nappes in Oscar II Land: Implications for Shortening Estimates / GEOFF M. MANBY & NIKOS LYBERIS The Southern Margin of the Belt of Emergent Thrusting on the North Coast of Isfjorden / KARSTEN PIEPJOHN & WERNER VON GOSEN Permo-Carboniferous Slivers Infolded in the Basement of Western Oscar II Land / FRANZ TESSENSOHN, WERNER VON GOSEN & KARSTEN PIEPJOHN Central Segment Basement-Cored Folds in Nordenskiold Land / NIKOS LYBERIS & GEOFF M. MANBY Involvement of Basal Tertiary Strata in the Fold-Belt Deformation in Nordenskiold Land / WERNER VON GOSEN, HANS-JURGEN PAECH & KARSTEN PIEPJOHN Thrust Tectonics North of Van Keulenfjorden / WERNER VON GOSEN & KARSTEN PIEPJOHN Structure of the West Spitsbergen Fold-and-Thrust Belt in Wedel Jarlsberg Land / GEOFF M. MANBY & NIKOS LYBERIS Southern Segment Polyphase Deformation in the Eastern Hornsund Area / WERNER VON GOSEN & KARSTEN PIEPJOHN Decollement Structures in the Triassic South of Hornsund / FRANZ TESSENSOHN, FRIEDHELM THIEDIG, GEOFF M. MANBY & NIKOS LYBERIS Involvement of the Hornsund High in the Fold-Belt Deformation / FRIEDHELM THIEDIG, GEOFF M. MANBY & KARSTEN PIEPJOHN Structural Setting of the West Spitsbergen Fold-and-Thrust Belt in Southern Sørkapp Land / WERNER VON GOSEN, KARSTEN PIEPJOHN & HANS-JÜRGEN PAECH Stress Patterns in the West Spitsbergen Fold-and-Thrust Belt / GEOFF M. MANBY & NIKOS LYBERIS Role of the Tertiary Compressive Structures in the Central Basin, Spitsbergen / HANS-JÜRGEN PAECH The Relationship of the Ny-Alesund Tertiary to the West Spitsbergen Fold-and-Thrust Belt / KARSTEN PIEPJOHN, KERSTIN SAALMANN, FRIEDHELM THIEDIG & HANS-JÜRGEN PAECH Structures in the Tertiary Sediments of the Forlandsundet Graben / WERNER VON GOSEN & HANS-JÜRGEN PAECH Coalification in Post-Caledonian Sediments on Spitsbergen / HANS-JÜRGEN PAECH & JOACHIM KOCH TIMING Paleontology Paleogene Calcareous Nannofossils from the Firkanten and Sarsbukta Formations on Spitsbergen / PAVEL CEPEK Conflicting Interpretations of the Tertiary Biostratigraphy of Spitsbergen and New Palynological Results / PAVEL CEPEK & WILFRIED KRUTZSCH New Biostratigraphic Data from West Spitsbergen Based on Conodonts / FRIEDRICH W. LUPPOLD Conodont Stratigraphy of the Carboniferous and Permian Strata from Brøggerhalvøya and the Billefjorden Trough / WERNER BUGGISCH, MICHAEL JOACHIMSKI, HARALD LÜTZNER, FRIEDHELM THIEDIG & HEIKO HÜNEKE An Upper Cretaceous Microflora from Spitsbergen / WILFRIED KRUTZSCH Isotope Geochronology K/Ar Dating Attempts on Rocks from the West Spitsbergen Fold-and-Thrust Belt and the Central Basin / FRANZ TESSENSOHN, FRIEDHELM HENJES-KUNST & STEFAN KRUMM CONCLUSION The Evolution of the West Spitsbergen Fold-and-Thrust Belt / CASE TEAM , Zusammenfassungen in englischer, deutscher und russischer Sprache