Earth System Science Definitions Flashcards
What does the biosphere represent in the Earth System?
Life
The biosphere encompasses all living organisms on Earth.
What is the hydrosphere?
Liquid Water
The hydrosphere includes all water in liquid form on Earth, including oceans, rivers, and lakes.
Define the lithosphere.
Rocks/planets crust
The lithosphere is the rigid outer layer of the Earth, including the crust and upper mantle.
What does the atmosphere consist of?
Gases
The atmosphere is a layer of gases surrounding the Earth, essential for life.
What is the cryosphere?
Solid water (ice)
The cryosphere includes all frozen water on Earth, such as glaciers and ice caps.
What percentage of the atmosphere is made up of nitrogen, oxygen, and argon?
99.9%
The composition is approximately 78% N2, 21% O2, and 0.9% Ar.
What initiates atmospheric chemistry?
Photochemistry
Photochemistry is driven by sunlight and involves reactions like photolysis.
What is the bond strength of O=O in oxygen?
497 kJ/mol (λ < 242 nm)
This indicates that a high energy UV photon is needed for O2 dissociation.
What is the bond strength of ozone (O3)?
101 kJ/mol (λ < 1180 nm)
Ozone has a weaker bond, making it more easily photolyzed than O2.
What factors affect the transmission of light through the atmosphere?
Ozone and oxygen amount, scattering by aerosol particles
Transmission varies with altitude and the presence of these gases.
True or False: Oxygen can be photolyzed in the troposphere.
False
There are no solar photons at wavelengths < 242 nm in the troposphere.
What determines the oxidation capacity of the troposphere?
OH radical
The OH radical is crucial for the oxidation reactions that occur in the troposphere.
What are primary emissions?
Natural and manmade sources emit gases
These emissions enter the atmosphere and undergo various chemical reactions.
What are secondary air pollutants?
Pollutants formed by chemical processes in the atmosphere
Examples include tropospheric ozone and secondary organic aerosol.
What is the role of OH radicals in tropospheric chemistry?
Initiate oxidation chemistry
OH radicals react with various compounds, impacting atmospheric chemistry.
What is a reservoir compound?
Slows down radical production by quenching reactions
Reservoir compounds can capture radicals and reduce their availability for reactions.
What is the average time a molecule of ‘X’ persists in the atmosphere called?
Chemical lifetime
This lifetime indicates how long a molecule remains before being removed by reactions.
What happens to ozone in polluted areas?
Higher production rates of ozone
Due to the presence of NOx, VOCs, and sunlight.
What does NO2 contribute to in the atmosphere?
Source of tropospheric ozone
NO2 photolysis produces radicals that lead to ozone formation.
What are PM10 and PM2.5?
PM10 = up to 10μm diameter, PM2.5 = up to 2.5μm diameter
These classifications relate to inhalability and health impacts.
What is the consequence of reducing NOx emissions in urban areas?
May lead to increased ozone production rates
This occurs because NOx plays a crucial role in ozone formation.
What are the health impacts of exposure to fine particulate matter (PM)?
Heart disease, lung cancer, respiratory issues
PM exposure is linked to various serious health conditions.
What role do meteorological conditions play in ozone concentrations?
Affect ozone levels during warm, sunny weather
Ozone can be transported across borders, necessitating international cooperation.
What is the impact of nitrogen dioxide emissions from road traffic?
Peaks during morning and evening rush hours
Resulting from high temperatures in combustion chambers.
