Atmospheric Energy Balances and Temperature Effects

Earth's Energy Balance

Balance of solar radiation inputs and outputs.

Insolation

Incoming solar radiation intercepted by Earth.

Shortwave Radiation

Includes UV, visible light, near infrared wavelengths.

Longwave Radiation

Thermal infrared wavelengths emitted by Earth.

Transmission

Uninterrupted passage of energy through mediums.

Heat

Flow of kinetic energy between substances.

Kinetic Energy

Energy of motion measured as temperature.

Sensible Heat

Heat perceived by humans as temperature.

Latent Heat

Energy gained or lost during state changes.

Radiation

Heat transfer via electromagnetic waves.

Conduction

Molecule-to-molecule heat transfer through substances.

Convection

Heat transfer via physical mixing or circulation.

Advection

Horizontal movement of air or water masses.

Scattering

Reflection of insolation back into space.

Diffuse Radiation

Energy reaching Earth after scattering.

Rayleigh's Scattering

Shorter wavelengths scatter more, creating blue sky.

Mie Scattering

Even scattering of all wavelengths by larger particles.

Refraction

Bending of light as it passes through mediums.

Albedo

Reflective quality of a surface, percentage of insolation reflected.

Absorption

Assimilation of radiation, converting energy forms.

Greenhouse Effect

Trapping of heat by atmospheric gases.

Global Dimming

Pollution-related decline in insolation to Earth's surface.

Cloud Effects

Influence of cloud cover on radiation balance.

Green Roofs

Urban roofs transformed into green spaces.

Extensive Green Roofs

Lightweight roofs with drought-resistant plants.

Wien's Law

Hotter objects emit shorter wavelengths.

Thermal Infrared

Longwave radiation associated with heat.

Pollutants

Substances that can affect atmospheric conditions.

Ozone

Gas that absorbs UV radiation in the atmosphere.

Intensive Green Roofs

Heavier with high plant diversity; supports trees, shrubs, and is often used in public areas or condos, requiring more structural support.

Environmental Benefits of Green Roofs

Cool buildings, reducing air conditioning needs and air pollutants from energy production; they also manage stormwater by absorbing and evaporating water, preventing sewer overflows.

Waterproofing Layer

Essential to prevent leaks.

Root Barrier

Prevents roots from damaging waterproofing.

Drainage Layer

Prevents water pooling during heavy rainfall.

Filter Membrane

Keeps particles from clogging drainage.

Growing Medium

Lightweight volcanic rock and organic material designed for different plants.

Green Roof Professional (GRP)

Professional Certification introduced for experts in green roof design.

Urban Agriculture Potential

Green roofs can grow food (e.g., mint, tomatoes), promoting local agriculture, reducing transport needs, and encouraging social interaction.

Maintenance of Green Roofs

Essential to prevent trees from growing on extensive roofs, as they may damage the structure without proper root barriers.

Broader Impact of Green Roofs

Enhance biodiversity, improve air quality, beautify urban areas, and support sustainability goals.

Pros of Solar Power

Point source generation, renewable, no emissions during operation, low maintenance.

Cons of Solar Power

Producing and disposal of components, long term energy storage, consistency of power supply.

Abundant Solar Power

Earth receives 173,000 terawatts of solar power, far exceeding global energy needs.

Solar Cell Basics

Solar panels consist of silicon-based solar cells, where n-type and p-type silicon layers create an electric field at their junction.

Photon Interaction

Photons from sunlight knock electrons loose in the silicon, creating a positive hole; the electric field directs electrons and holes to opposite sides, generating a current.

Energy Collection in Solar Cells

Electrons flow through an external circuit, doing electrical work before returning, allowing solar cells to last for decades.

Challenges to Full Solar Reliance

Uneven Solar Distribution varies by location, weather, and day/night cycle, requiring efficient energy transfer and storage systems.

Efficiency Limitations of Solar Cells

Most solar cells are 15-20% efficient, with the best reaching 46%.

Feasibility of Solar Energy

Technically possible to power the world with solar energy using current technology, but would need significant funding, infrastructure, and space (e.g., Sahara Desert area).

Impact of Solar Energy in Developing Areas

Solar energy is often cheaper and safer in sunny, grid-limited regions, providing a vital energy source where traditional grids are unreliable.

Normal Lapse Rate

Rate at which temperature drops, lapse rate of the troposphere is 6.5 degrees for every 1k meters.

Cloud Cover Effects

Having moderating effect on temperature; raises minimum night time temperature and lowers daily maximum temperature.

Specific Heat of Water

Specific Heat (capacity of substance to hold heat) of water is 4 times greater than that of soil.

Heat Wave

Prolonged period of abnormally high temperatures, usually, but not always in association with humid weather.

Positive Temperature Anomalies

Temperature above average value.

Negative Temperature Anomalies

Temperatures below average value.

Humidex

Developed by Canadian meteorologists, first used in 1965 to describe impact of high humidity on human comfort.

Dry Heat

Conditions of low humidity; more comfortable for humans but can be deceptive and therefore quite dangerous.