UPSC MainsGEOGRAPHY-PAPER-I201410 Marks150 Words
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Q2.

Discuss the salient features of 'sirocco' and 'mistral'.

How to Approach

The question requires a comparative discussion of two local winds – Sirocco and Mistral. A good answer will define each wind, explain their origin, characteristics (temperature, humidity, impact), and geographical areas they affect. Structuring the answer by dedicating a section to each wind, followed by a comparative table, will be effective. Focus on the mechanisms driving these winds and their impact on the regions they traverse.

Model Answer

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Introduction

Local winds play a significant role in regional climates, influencing temperature, humidity, and precipitation patterns. Sirocco and Mistral are two prominent examples of such winds, originating from different geographical locations and possessing distinct characteristics. Sirocco, a hot, dry wind originating from North Africa, impacts Southern Europe, while Mistral, a cold, dry wind, originates in the Rhône Valley of France and affects the Mediterranean region. Understanding these winds is crucial for comprehending the climatic diversity of Europe and North Africa.

Sirocco

Sirocco is a Mediterranean wind that forms when high-pressure systems over North Africa combine with low-pressure systems over Southern Europe. It originates in the Sahara Desert and travels northward across the Mediterranean Sea, picking up moisture along the way.

  • Origin: Sahara Desert, North Africa.
  • Characteristics: Hot (often exceeding 40°C), dry to humid (depending on the distance travelled over the sea), carries dust and sand particles.
  • Impact: Causes hazy skies, reduces visibility, increases temperatures, and can lead to dust storms. It can also exacerbate respiratory problems.
  • Affected Regions: Italy, Spain, Malta, Greece, and North African countries.

Mistral

Mistral is a strong, cold, northwesterly wind that blows from the Rhône Valley in southern France towards the Mediterranean Sea. It is caused by the pressure gradient between the high-pressure systems over the European continent and the low-pressure systems over the Mediterranean Sea.

  • Origin: Rhône Valley, Southern France.
  • Characteristics: Cold (temperatures can drop significantly), dry, strong and gusty (can reach speeds of 90 km/h).
  • Impact: Clears the air of pollution, lowers temperatures, and can cause rough seas. It is beneficial for agriculture by preventing fungal diseases.
  • Affected Regions: Southern France, Italy, Corsica, and Sardinia.

Comparative Analysis: Sirocco vs. Mistral

Feature Sirocco Mistral
Origin Sahara Desert, North Africa Rhône Valley, Southern France
Temperature Hot Cold
Humidity Dry to Humid Dry
Speed Moderate Strong & Gusty
Impact Dust storms, hazy skies, increased temperatures Clear air, lowered temperatures, rough seas
Beneficial Aspects None significant Prevents fungal diseases in agriculture

The frequency of both winds can vary seasonally. Sirocco is more common during the spring and autumn, while Mistral is strongest during the winter and spring. Both winds are influenced by large-scale atmospheric pressure systems and can have significant socio-economic impacts on the regions they affect.

Conclusion

In conclusion, Sirocco and Mistral, though both Mediterranean winds, exhibit contrasting characteristics and impacts. Sirocco brings heat and dust from the Sahara, while Mistral delivers cold, dry air from the Rhône Valley. Understanding the dynamics of these winds is crucial for predicting regional weather patterns and mitigating their potential hazards. Climate change may alter the frequency and intensity of these winds, necessitating further research and adaptation strategies.

Answer Length

This is a comprehensive model answer for learning purposes and may exceed the word limit. In the exam, always adhere to the prescribed word count.

Additional Resources

Key Definitions

Local Winds
Winds that blow over a limited geographical area, influenced by local topography and temperature variations. They differ from planetary winds which blow consistently over large areas.
Pressure Gradient
The difference in atmospheric pressure between two points. A steeper pressure gradient results in stronger winds, as air moves from high to low pressure areas.

Key Statistics

The Mistral can blow for up to 200 days a year in some areas of Provence, France.

Source: Météo-France (as of knowledge cutoff 2023)

Mistral winds can reach speeds of over 90 km/h (56 mph) in exposed areas.

Source: World Meteorological Organization (as of knowledge cutoff 2023)

Examples

Impact of Sirocco on Italy

During Sirocco events, Rome often experiences a significant increase in particulate matter (PM10) levels, exceeding safe limits and impacting public health. This leads to advisories for vulnerable populations.

Frequently Asked Questions

How does the Mediterranean Sea influence Sirocco?

The Mediterranean Sea adds moisture to the Sirocco wind, making it less dry than when it originates in the Sahara. The sea also moderates the temperature somewhat, but it remains a hot wind.

Topics Covered

GeographyClimatologyWindsAtmospheric PressureRegional Climate