Module 5 Flashcards
Describe the difference between specific and latent heat
Specific heat is energy required to increase the temperature of a substance. Latent heat is energy required to change the physical state of a substance
Distinguish between relative humidity and specific humidity. How do the quantities change with the changes in air temperatures?
Specific humidity refers to how much water vapour is actually present in the air.
Relative humidity is the ratio of specific humidity to maximum humidity. Refers to how close the air is to saturation at its current temperature
Diurnal cycle:
Maximum humidity increase due to warming air temperatures. Specific humidity is constant. Relative humidity gradually decreases
Define the term adiabetic processes
Adiabatic Means occurring without a loss or gain of heat.
Adiabetic processes: temperature changes resulting from expansion and compression of air due to pressure fluctuations. Air cools as it rises and expands or air warms as it sinks and compresses
Compare and contrast the terms: environmental lapse rate ELR, dry adiabetic lapse rate DAR, saturated (moist) adiabetic lapse rate MAR
ELR: average decrease in temperature with increasing altitude.
DAR: The rate at which dry air cools by expansion (if ascending) or heat by compression (if descending). Dry refers to air that is less than saturated
MAR: The rate at which an ascending air parcel that is saturated colours by expansion
Distinguish between stable, conditionally unstable, and unstable conditions in the atmosphere
Unstable: as the environmental lapse rate is greater than the dry adiabetic lapse rate
Conditionally unstable: as the environmental lapse rate is greater than the moist adiabetic lapse rate in less than a dry adiabetic lapse rate
Stable: as the environmental lapse rate is less than the moist adiabetic lapse rate
What are condensation nuclei?
In cloud formation there are two necessary conditions: first the air must be saturated and there must be a substantial quantity of small airborne particles for water vapour to collect on.
Search particles are known as condensation nuclei
Identify potential sources for condensation nuclei.
Hint: natural & anthropogenic
Natural sources of cloud condensation nuclei CCN: meteoric dust, windblown clay and silt, volcanic material, smoke from forest fires, and sea salt
Anthropogenic CNN sources: combustion products (sulphur and nitrogen compounds)
Distinguish between low level, mid-level, and high-level clouds in the troposphere
Low: up to 2000 m (Stratocumulus, Stratus, Nimbostratus, cumulus) Mid: 2000 to 6000 m (Altocumulus, altostratus, cumulonimbus) High: 6000 to 13,000 m (Cirrocumulus, Cirrus, Cirrostratus)
Note-Vertically developed: near surface to 13,000 m
Define dewpoint temperature and lifting condensation level
The dewpoint temperature is the temperature at which a given mass of air becomes saturated and Annette condensation begins to form water droplets.
The condensation lifting level is defined as the height at which the relative humidity of an air parcel will reach 100%, or be saturated, with respect to liquid water when it is cooled by dry adiabetic lifting
Describe the process that contribute to the generation of convectional precipitation
The air above warm surfaces is heated and rises. The warmer services produced confectioner lifting due to local heating.
Aka warm air rises in altitude to dewpoint temp, initiating condensation and formation of clouds
Describe the process that contribute to the generation of orographic precipitation
- Warm, moist air forced upward by windward slope of mountain chain.
- Condensation level, clouds form.
- Air rises and cools, precipitation occurs.
- Airflow continues to Leeward side.
- Hot, dry air on the Leeward side, it results in rainshadow shadow
Define air mass
Air masses is a distinctive body of air, covering thousands of kilometres squared, with a homogenous properties of temperature, specific humidity, and stability.
Initially the physical properties reflect the characteristics of its source region and the interactions of air masses produce weather patterns
Describe how to classify air masses
Classifying air masses according to the moisture and temperature characteristics of their source region.
Moisture: “m” for Maritime (moist) and “c” for Continental (dry)
Temperature: A for arctic, P for polar, T for tropical, E for equatorial, and AA for Antarctic
These classifications are then combined; mT for maritime tropical or cP for continental polar
What are the patterns of global precipitation?
Hint: high pressure and low pressure systems
High pressure systems: Subtropical high (warm, dry) Polar high (very cold, dry)
Low pressure systems:
Intertropical convergence zone-warm, moist; convergent lifting
Midlatitudes-polar front-cool, moist; frontal lifting
Describe the processes that influence the generation of precipitation within Hadley cells in the inter-tropical regions
Air flows toward an area of low pressure, such as ITCZ.
Convergence lifting is when air near the surface flows together and is pushed upward when it is squeezed together. The rising air in all lifting mechanisms causes an updraft which keeps cloud particles suspended regardless of gravity.
This ascension cools the air and condensation occurs
