Cold Wave Conditions Hit North India Earlier This Year

North India, particularly Delhi, Haryana, and Punjab, is currently experiencing an unusual cold wave. The India Meteorological Department (IMD) has issued a yellow alert for cold weather, indicating that temperatures have dipped earlier than expected this season. The average minimum temperature in Chandigarh is reported at 6.8 degrees Celsius, with recent lows recorded at 4.7 degrees Celsius. This early onset of cold weather has raised concerns regarding its impact on health and agriculture.

Temperature Trends in North India

Recent temperature readings indicate a stark contrast between daytime and nighttime conditions. Maximum temperatures have fluctuated between 20.5°C and 24.8°C, which aligns with seasonal averages. However, minimum temperatures have plummeted to as low as 1.6°C in Haryana and 1.8°C in Punjab. This disparity marks deviation from normal patterns, with some areas experiencing temperatures 4.7°C below average.

Defining Cold and Severe Cold Waves

The IMD categorises a cold wave as a condition where air temperature becomes dangerous to human health. For plains, a cold wave is defined when the minimum temperature is 10°C or lower, or 4.5°C to 6.4°C below normal. A severe cold wave occurs when temperatures drop below 2°C or exceed 6.5°C below the average. In hilly regions, cold waves are declared when temperatures fall to 0°C or lower.

Causes of Early Cold Wave

The IMD attributes the early onset of cold waves to several meteorological factors. Two western disturbances have influenced weather patterns, bringing winter precipitation to the region. Additionally, a strong subtropical westerly jet stream has been prevalent, affecting atmospheric conditions. Prolonged dry spells and low rainfall have resulted in decreased soil moisture, enhancing the cooling effect during clear nights.

Impact of Weather Conditions

The current weather conditions have resulted in colder nights and relatively warm days. The IMD explains that clear skies and dry weather allow heat to escape at night, leading to lower temperatures. In contrast, sunny days contribute to higher daytime temperatures. This pattern differs from previous years, where both day and night temperatures would drop during cold waves.

Health Implications of Cold Waves

Cold waves can have severe health impacts, particularly on vulnerable populations. Respiratory issues, joint pain, and other health problems can arise from prolonged exposure to low temperatures. The homeless and impoverished communities are especially at risk, as they often lack adequate shelter and warmth during extreme cold conditions.

Future Outlook for North India

The IMD forecasts that cold wave conditions will persist across the region, with severe conditions expected in isolated areas until at least mid-December. Nighttime temperatures are predicted to remain below normal if current weather patterns continue.

Questions for UPSC:

1. Critically analyse the impact of cold waves on health and agriculture in North India.
2. Explain the role of western disturbances in influencing winter weather patterns in India.
3. What are the effects of climate change on weather anomalies such as early cold waves? Provide suitable examples.
4. What is the significance of soil moisture in weather patterns? How does it affect temperature fluctuations during winter months?

Answer Hints:

1. Critically analyse the impact of cold waves on health and agriculture in North India.

1. Cold waves can lead to severe health issues, including respiratory diseases and joint pain, particularly affecting vulnerable populations.
2. Agricultural output may decline due to frost damage to crops, affecting food security and farmer incomes.
3. Livestock may suffer from exposure to low temperatures, impacting dairy and meat production.
4. Increased demand for heating and healthcare services can strain local resources and infrastructure.
5. Prolonged cold conditions can disrupt planting and harvesting schedules, leading to economic losses for farmers.

2. Explain the role of western disturbances in influencing winter weather patterns in India.

1. Western disturbances are storm systems originating from the Mediterranean that bring moisture and precipitation to northwest India.
2. They affect winter weather by causing rainfall and snowfall in the western Himalayan region.
3. These disturbances modify atmospheric conditions, leading to fluctuations in temperature and increased cold wave occurrences.
4. They also contribute to soil moisture replenishment, which is crucial for agriculture during dry spells.
5. Timing and intensity of western disturbances can determine the severity of winter conditions across northern plains.

3. What are the effects of climate change on weather anomalies such as early cold waves? Provide suitable examples.

1. Climate change leads to increased variability in weather patterns, resulting in more frequent and intense weather anomalies.
2. Early cold waves may occur due to shifts in jet streams and atmospheric circulation patterns caused by global warming.
3. Examples include the unusual onset of cold waves in North India in December, which is earlier than the historical average.
4. Changing precipitation patterns can lead to droughts followed by sudden cold snaps, exacerbating agricultural challenges.
5. Climate models predict that such anomalies will become more common, impacting ecosystems and human livelihoods.

4. What is the significance of soil moisture in weather patterns? How does it affect temperature fluctuations during winter months?

1. Soil moisture plays important role in regulating surface temperatures and heat retention during the day and night.
2. High soil moisture can moderate temperature extremes, while low moisture enhances cooling during clear nights.
3. Dry soil conditions lead to rapid heat loss at night, resulting in colder temperatures, as observed in the current cold wave.
4. Moisture levels influence plant health and agricultural productivity, affecting food supply and economic stability.
5. Effective soil moisture management is vital for mitigating the impacts of extreme weather conditions, including cold waves.