© oxford university press, 2008. all rights reserved. 1 chapter 5 chapter 5 hydrologic systems and...
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© Oxford University Press, 2008. All rights reserved.1
Chapter 5
CHAPTER 5
HYDROLOGIC SYSTEMS AND ATMOSPHERIC PROCESSES
© Oxford University Press, 2008. All rights reserved.1
Chapter 5
INTRODUCTION• Water is a unique substance• The hydrologic cycle
Precipitation
Evaporation
Transpiration
Sublimation
Runoff and infiltration
Changes of state of water
© Oxford University Press, 2008. All rights reserved.1
Chapter 5
MOISTURE IN THE ATMOSPHERE
• Latent heat of evaporation
• Defining saturation
• Spatial distribution in Australia
• Descriptions of atmospheric moisture– Relative humidity– Mixing ratio
© Oxford University Press, 2008. All rights reserved.1
Chapter 5
CLOUD FORMATION
• Formation requirements– Water vapour– Nucleation– Trigger mechanisms– Is cloud seeding effective to create rain?
© Oxford University Press, 2008. All rights reserved.1
Chapter 5
BASIC THERMODYNAMICS
• Definitions
• Lapse rates (dry, wet)
• The role of saturation
• Calculation of cloud location using T and Td
© Oxford University Press, 2008. All rights reserved.1
Chapter 5
ESTIMATING ATMOSPHERIC STABILITY
• Adiabatic lapse rates versus background atmospheric temperature
• Estimating states of stability– Absolutely unstable– Conditionally unstable– Stable
• Inversions
© Oxford University Press, 2008. All rights reserved.1
Chapter 5
TRIGGER MECHANISMS
• Convection
• Orographic
• Frontal
• Others
© Oxford University Press, 2008. All rights reserved.1
Chapter 5
CLOUD DROPLET FORMATION AND GROWTH
• Condensation around nuclei• Collision/coalescence• Wake capture• The importance of convection and
turbulence• Identifying cloud types• Altocumulus lenticularis cloud formation
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Chapter 5
DEW AND FOG• Dew and frost formation
• Fog formation and types– Radiation– Advection– Steam– Upslope– Global frequency distribution– Fogwater as a resource
© Oxford University Press, 2008. All rights reserved.1
Chapter 5
SYNOPTIC AND REGIONAL PRECIPITATION
• Fronts and frontal theory– Types of fronts– Lifecycle in Australia– The influence of upper tropospheric waves – Consequences
• Squall lines• Thunderstorms
© Oxford University Press, 2008. All rights reserved.1
Chapter 5
THUNDERSTORMS AND THEIR HAZARDS
• Scale of thunderstorm systems• Initial formation• Mature stage• Old age• The role of the jet stream• Hazards
– Hail– Lightning– Downbursts and microbursts– Tornadoes
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Chapter 5
TORNADOES
• Definition
• Conditions for formation
• Spatial and seasonal distributions
• Fujita destruction scale
© Oxford University Press, 2008. All rights reserved.1
Chapter 5
PRECIPITATION DISTRIBUTION
• Northern Australia
• Global