Acid Rain and Stratospheric Ozone

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Questions and Answers

What is produced when reservoir gases react on the PSC?

Chlorine and Nitrogen Oxide

Ozone and Hydrogen Peroxide

Chlorine and Nitric Acid (correct)

Chlorine and Water

What role does sunlight play in the destruction of ozone?

It prevents the reaction of Cl with ozone.

It photolyzes Cl2 to release chlorine atoms. (correct)

It absorbs excess chlorine in the stratosphere.

It enhances the stability of ozone.

How many ozone molecules can one chlorine atom destroy over time?

Millions

Dozens

Hundreds

Thousands (correct)

What is the purpose of the Montreal Protocol?

To restrict the production of chlorofluorocarbons. Signup and view all the answers

What type of radiation do greenhouse gases particularly absorb?

Infrared radiation Signup and view all the answers

What is the main effect of selective absorption by greenhouse gases?

It creates a greenhouse effect by trapping heat. Signup and view all the answers

Which type of radiation is categorized as shortwave radiation?

Ultraviolet rays Signup and view all the answers

What occurs when longwave radiation is emitted by the Earth?

Some radiation escapes through the atmospheric window. Signup and view all the answers

What compounds primarily lead to the formation of acid rain?

SO2 and NOx Signup and view all the answers

Which of the following describes wet deposition?

Acid rain, fog, or snow Signup and view all the answers

What is a direct consequence of acid rain on forest ecosystems?

Damages leaves and needles Signup and view all the answers

How does ozone form in the stratosphere?

When ultraviolet radiation splits diatomic oxygen molecules Signup and view all the answers

What factors contribute to rapid ozone loss in Antarctica?

Global wind patterns and polar stratospheric clouds Signup and view all the answers

What happens to ozone when it absorbs UV radiation?

It splits into diatomic oxygen and a single oxygen atom Signup and view all the answers

What is the global average concentration of ozone in the stratosphere measured in Dobson units (DU)?

300 DU Signup and view all the answers

Which of the following describes the effects of acid rain on soil?

Depletes essential nutrients Signup and view all the answers

Study Notes

Acid Rain Formation and Impacts

Acid rain forms when sulfur dioxide (SO2) and nitrogen oxides (NOx) transform into sulfuric acid (H2SO4) and nitric acid (HNO3).
These acidic particles are deposited through wet deposition (rain, fog, snow) or dry deposition (gases and particles).
Acid rain harms aquatic ecosystems by damaging plant and animal species.
Forest ecosystems are impacted as acid rain damages leaves and needles, weakens tree resistance to cold, and hinders plant germination and reproduction.
Acid rain depletes soil nutrients and increases aluminum concentration, further affecting plants and trees.
Acid rain accelerates the erosion and destruction of buildings and architecture.

Stratospheric Ozone

The stratosphere contains about 90% of the Earth's atmospheric ozone.
The average global concentration of ozone in the stratosphere is 300 Dobson units (DU), equivalent to a 3mm thick layer if compressed.
Ozone is distributed throughout the stratosphere with the highest concentrations at an altitude of approximately 14 miles.

Ozone Formation and Destruction

Ozone formation is a two-step process:
- Ultraviolet radiation from the sun splits diatomic oxygen molecules (O2) into two oxygen atoms (2O).
- These individual oxygen atoms collide and bind with other O2 molecules, forming ozone (O3).
Ozone destruction occurs when it absorbs UV radiation, splitting the ozone molecule into a diatomic oxygen molecule (O2) and a single oxygen atom (O).
This single oxygen atom then combines with another O2 molecule to form ozone, creating a continuous cycle.

Ozone Loss in Antarctica

Ozone loss is prominent in Antarctica due to the transportation of reservoir gases (ClONO2 and HCl) to the poles by global wind patterns.
These reservoir gases do not directly destroy ozone but accumulate on polar stratospheric clouds (PSCs) during mid-March.
The formation of PSCs occurs when the sun disappears below the horizon, leading to frigid vortex winds and the combination of nitric acid, sulfur-containing gases, and water vapor.
On PSCs, reservoir gases react to form Cl2 and HNO3.
When sunlight returns in the southern hemisphere spring, Cl2 is photolyzed, releasing Cl atoms.
These Cl atoms react with ozone: Cl + O3 → ClO + O2, leading to rapid ozone destruction due to high Cl2 concentrations.

CFCs and the Montreal Protocol

Chlorofluorocarbons (CFCs) release chlorine atoms when exposed to ultraviolet radiation, initiating ozone destruction.
While ozone is naturally destroyed by UV, CFCs accelerate this process, resulting in significant ozone depletion.
Each chlorine atom can destroy thousands of ozone molecules.
The Montreal Protocol, an international agreement established in 1987, restricted CFC production.
This agreement has been enhanced to include new controlled substances, accelerate control measures, and phase out the production of certain gases.

Electromagnetic Spectrum

All solar radiation reaches Earth in wave form.
UV light, a shortwave radiation, is part of the electromagnetic (EM) spectrum.
Wavelengths are the distances between the crests of two waves.
Shortwave radiation comprises 90% of solar radiation including gamma rays, UV rays, and visible light.
Longwave radiation/infrared radiation is emitted by the Earth.

Selective Absorption and the Greenhouse Effect

Greenhouse gases (CO2, Methane, Nitrous oxide, CFCs, and water vapor) selectively absorb certain wavelengths of radiation.
The greenhouse effect happens when absorbed energy is re-emitted as infrared radiation (longwave radiation).
Some radiation escapes through the atmospheric window, providing a cooling effect.
However, greenhouse gases absorb infrared radiation, exciting their electrons and generating more infrared energy.
This re-radiated infrared energy contributes to global warming.

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Description

This quiz covers the formation and impacts of acid rain, as well as the characteristics of stratospheric ozone. Learn how pollutants like sulfur dioxide and nitrogen oxides contribute to acid rain and the role of ozone in the atmosphere. Test your understanding of these environmental issues.