Global System
Weather vs Climate
The weather refers to specific atmospheric conditions at a particular location at a specific time.
Temperature
Cloud Cover
Precipitation
Humidity
Climate is the average weather condition in a region measured over several years.
Biosphere
Narrow zone around Earth that can support life. Makeup of three parts, atmosphere(Sky), hydrosphere(Sea), and lithosphere(Ground).
The Albedo of a surface is the percent of solar radiation that it reflects and the average albedo for the Earth's surface is about 30%.
Atmosphere
78.08% make of Nitrogen, 20.95 make 20.95 and 0.97 is other gases.
The gases in the atmosphere: different layers contain different types and amounts of gases.
Cloud cover and atmospheric dust
Inversion is a reversal of temperature change with altitude. Specific atmospheric conditions trap colder air closer to the ground.
Troposphere
From Earth’s surface to 10km.
15’C to -60’C (Decreases with altitude)
It contains 80% of the atmospheric gases
Has the most living organisms
Stratosphere
From 10 km to 50 km
60’C to 0’C
Contain the ozone layer
O₂ → O₃
The conversion of stratospheric oxygen to ozone is an exothermic process (Releases heat, causing the temperature of the immediate surroundings to rise). This accounts for the temperature increase.
Mesosphere
From 50 km to 80 km
0’C to -100’C
Contains only traces of water vapour.
Thermosphere
From 80km to 300 km
-100’C to 1500’C
Very little gas
The Electromagnetic Spectrum
The solar energy that radiates from the sun contains many different types of radiation, which are classified according to different wavelengths. The amount of this energy that is received on the earth's surface is called insolation. Many implications for climate on different parts of the Earth.
Insolation & The Angle Of Inclination
The Earth’s axis of rotation is tilted at an angle of 23.5 from a line drawn perpendicular to its orbital plane. This is called the angle of inclinations. The tilt of the earth changes the insolation at different parts of the earth at different times of the year. A solstice is one of two points in Earth’s orbit when the poles are most tilted towards or away from the sun. An Equinox is when the number of daylight hours is exactly equal to the number of hours of night. The ray is the angle between the ray and a line that is drawn perpendicular to the earth's surface.
The area near the equator receives more solar energy. The area near the poles receives less solar energy. This has major implications for the climate in different parts of the earth.
Natural Greenhouse Effect
When solar energy is absorbed by the earth’s surface, some of it is re-emitted into the atmosphere in the form of infrared radiation and this is absorbed and stored by mainly water vapour in the atmosphere. Without this natural greenhouse effect, our average atmospheric temperature would be below 0’C. Other greenhouse gases, some of them man-made, absorb and store thermal energy. These contribute to the artificial greenhouse effect.
Net Radiation Budget
Incoming Radiation = Outgoing radiation
Incoming Radiation
Solar Radiation that reaches the surface of the Earth (isn’t reflected by the atmosphere)
Outgoing Radiation
Thermal radiation that is emitted by the Earth's surface into space (not absorbed by the greenhouse gases).
For the entire planet, the energy budget is generally balanced (incoming = outgoing) This keeps the average global temperature fairly steady. The amount of energy absorbed and emitted changes with latitude.
The polar regions experience a net radiation budget deficit due to receiving less incoming radiation (low insolation) and having higher albedo, which reflects more energy. In contrast, regions near the equator have a net radiation budget surplus, as they receive more incoming radiation (high insolation) and have lower albedo, which absorbs more energy.
Heat Transfer
Radiation
The emission of energy as particles or waves. This energy, when absorbed by an object, will increase the kinetic energy and therefore temperature of the particles that make up the object.
Conduction
Every atom is physically bonded to its neighbours. If heat energy is supplied to one part of a solid the atoms vibrate faster. As they vibrate more, the bonds between atoms are shaken more. This passes vibrations on to the next atom, and so on.
Convection
The transfer of thermal energy through the movement of particles from one location to another. As the particles absorb energy they move apart, decreasing the density. The lower-density air/water will move up and the higher-density air/water will fall.
Effects of thermal Energy Transfer in the atmosphere
Atmospheric pressure is the pressure exerted by the air above any point on the Earth’s Surface. Colder air exerts more pressure than warm air since it is more dense. This difference in air pressure and temperature creates convection currents in the atmosphere. Wind is the movement of air from regions of high pressure to regions of low pressure.
Coriolis Effect
The bending of moving current in response to Earth’s rotation. The Coriolis effect causes winds in the two hemispheres to move in opposite directions. Convection currents and the Coriolis effect cause the global wind patterns.
Jet Stream
Narrow fast flowing “river” of air in the stratosphere. The strong wind (480 - 640 km/h) are typically thousands of lkilometers long and hundred of kilometer wide.
Thermal Energy Transfer in the Hydrosphere
Thermal energy is transferred through the hydrosphere from warmer latitudes to cooler polar regions largely due to global winds.
Specific Heat Capacity
The specific heat capacity is the amount of heat energy needed to raise the temperature of one gram of a substance by one degree Celsius.
Quantity of Thermal Energy
This is the amount of thermal energy that is released or absorbed by one gram of a substance when its temperature changes by one degree Celsius.
Q = m x c x t
Q = Thermals Energy (J)
m = mass (g)
c = Specific heat Capacity
t = Change in temperature (‘C)
Heat of Fusion
A substance is the amount of energy released or absorbed when it changes from a liquid to a solid, or a solid to a liquid.
Hfus = Q/n
Hfus = Heat of fusion (kJ / mol)
Q = Thermal Energy (kJ)
N = Number of moles of substance (mol)
N = m / M
N = Number of moles of substance (mol)
m = mass (g)
M = molar mass (g/mol)
Heat of Vaporization
A substance is the amount of energy released or absorbed when it changes from a gas to a liquid, or from a liquid to a gas.
Hvap = Q / n
Hvap = Heat of vaporization (kJ/mol)
Q = Thermal energy (kJ)
n = number of moles of substance ( mol)
Earth Biomes
A biome is a large geographical region with a specific climate that the plants and animals that inhabit it are adapted to. The cells and biomes are open systems that exchange matter and energy with their surroundings. The distribution of Earth’s biomes is affected by the amount of solar energy and precipitation received by different regions.
Canada Biomes
Tundra
Taiga
Deciduous Forest
Grassland
Tundra
Permafrost, bitter cold and high winds mean no trees or tall plants.
Little annual rainfall, but accumulation on top of permafrost.
Mountaintops around the world can be alpine tundra.
Taiga
Large terrestrial biome
Dominated by cone-bearing evergreen trees (coniferous)
Adapted to wavy snowfall
Deciduous Forest
Mid-latitudes, with enough moisture to support trees
Deciduous trees drop their leaves in winter
Grassland
Deep, rich topsoil means a loss of conversion to agriculture
Seasonal drought occasional fires and grazing by large mammals prevent shrub and tree establishment.
Rain forest
The greatest diversity of plants and animals
Closed tree canopy
Pronounced vertical stratification (layering)
Desert
Spare rainfall
Extreme temperature (hot and Cold)
Organisms adapt to conserve water
Many protective adaptations of plants to deter herbivory
Energy flow in the Global System
A Climatograph is a summary of the average temperature and precipitation for each month of the year. This tells us information about what biome a particular region might be in. Climatographs are often used to compare one region to another.
Climate Change - Examining the Evidence
This is a computer-generated image that makes predictions about the expected changes in global temperature based on expected increases in greenhouse gas levels. We will now take a look at the evidence that leads scientists to believe that this climate change is occurring. Recall that the natural greenhouse effect occurs because of the water vapour in the atmosphere. Human activity has had a large impact on the three other greenhouse gases causing the enhanced greenhouse effect. The global warming potential (GWP) of a greenhouse is a measure of its relative ability to trap thermal energy in the atmosphere. Carbon dioxide is used as the reference to which the other greenhouse gases are then compared. Persistence is how many years each gas will remain in the atmosphere.
Human Activity
Since the Industrial Revolution in the late 18th century, the level of carbon dioxide in the atmosphere has been increasing. Any process that releases carbon into the atmosphere is called a carbon source. Fossil fuels are formed from the remains of living organic materials, so they contain a loss of carbon and when burned, they release carbon dioxide and nitrous oxide. (N2O) into the atmosphere. Forests are called carbon sinks because photosynthesis removes carbon dioxide from the atmosphere. The size of Earth’s carbon sinks has been steadily decreasing because of human need for fuel and land for agriculture and industrialization. The combination of increased use of fossil fuels and the decrease in available carbon sinks has increased atmospheric carbon dioxide by about 32% over the last 200 years. Halocarbons are another class of man-made chemicals that can trap thermal energy in the atmosphere. They have a global warming potential of about 12,000. Many scientists believe that human activities since the Industrial Revolution have led to global warming, the observed overall increase in Earth’s average temperature.
4 Signs of Global Temperature Increasing
Flowers in the northern hemisphere have begun to bloom earlier and earlier over the past century.
The incidence of extreme weather events sucks as ice storms and floods have been on the rise.
Snow cover in some polar regions has decreased
The average level and temperature of the Earth’s oceans have been increasing.
Coral Reefs and dissolved CO2
Rising Carbon Dioxide in the atmosphere and the effects on ocean water are making it increasingly difficult for coral reefs to grow, say scientists. A study to be published online on March 13 2009 in Geophysical Research Letters by researchers… warns that if carbon dioxide reaches a double pre-industrial level, the coral reefs can be expected not just to stop growing, but also begin to dissolve all over the world.
Scientists on Climate Change
Scientists worldwide need to share data to develop strategies to best deal with climate change. Many advances in computer technology and data gathering have made this possible. There are several types of computer climate models, but the one that best reflects the world’s climate is called the general circulation model (GCM). GCM focuses on the mechanisms of thermal energy transfer in the atmosphere, the complex factors that influence them, and how they are changing. These changes have major implications for climate on different parts of Earth.
The Montreal Protocol (1987)
Signed by 182 countries, controls the production and consumption of substances that can cause ozone depletion. This recall that chlorofluorocarbons (CFCs) are substances that deplete the ozone layers. CFCs are to be phased out and replaced with hydrochlorofluorocarbons (HCFCs) which destroy the ozone much more slowly than CFCs.
United Nations Framework Convention on Climate Change (1994)
The Convention on Climate Change sets an overall framework for intergovernmental efforts to tackle the challenge posed by national policies and best practices. Launch national strategies for addressing greenhouse gas emissions and adapting to expected impacts, including providing financial and technological assistance to developing countries. Cooperate in preparing for adaptation to the impacts of climate change. The Convention enjoys near universal membership, with 189 countries having ratified it.
The Kyoto Protocol
An agreement under which industrialized countries will reduce their collective emissions of greenhouse gases by 5.2% compared to the year 1990. But note that, compared to the emissions levels that would be expected by 2010 without the Protocol, this target represents a 29% cut. Emission Reduction Credits is a country for taking action that contributes to the reduction of greenhouse gases. Countries receive credits through carious shared “clean energy” programs and “carbon dioxide sink” in the form of forests and other systems that remove carbon dioxide from the atmosphere. The United States is a notable exception, and that might be one of the reasons why the Kyoto Protocol is such a large issue in the media because they did not sign the agreement.
Stabilizing Greenhouse Gases
Carbon dioxide Sequestering is the process of capturing the exhaust from a fossil fuel combustion and pumping it back into Earth. The increase in pressure can be used to enhance the extraction of additional fossil fuel in derby wells. There is much concern however that the carbon will not remain captive and will leak back into the atmosphere over s span of decades or centuries.