Syllabus: Prelims Unit II - Geography of India
Current Heat Wave Situation in India
- Severe heat wave conditions affecting multiple states:
- Delhi
- Uttar Pradesh
- Punjab
- Rajasthan
- Combined impact of high temperatures and humidity on daily life
- Critical for understanding disaster management and climate change impacts
Types of Temperature Measurements
Dry Bulb Temperature
- Standard air temperature measurement
- Measured using an unwetted thermometer
- Represents ambient air temperature
- Primary reference for general weather reporting
Wet Bulb Temperature
- Definition: Lowest temperature achievable through water evaporation at constant pressure
- Measurement Method:
- Thermometer bulb wrapped in wet cloth
- Evaporative cooling causes temperature decrease
- Significance:
- Indicates atmosphere's water-holding capacity
- Measures evapotranspiration effects
- Critical for human comfort assessment
- Important for agricultural considerations
Dew Point Temperature
- Temperature at which air reaches 100% humidity
- Point where water vapor begins condensing into dew
- Key indicator for atmospheric moisture content
Humidity and Comfort Analysis
Relationship between Wet and Dry Bulb Temperatures
- Small difference indicates high humidity
- Large difference indicates low humidity
- Impact on Evaporative Cooling:
- Higher humidity reduces evaporative cooling efficiency
- Affects human body's natural cooling mechanism
Safety Thresholds
Previous Understanding
- Traditional safe limit: 35°C wet-bulb temperature
New Research Findings (Penn State University)
- Revised safety thresholds:
- Critical point: 31°C wet-bulb temperature with 50% humidity
- Alternative critical combination: 38°C with 60% humidity
- Human core temperature begins rising at lower levels
- Implications for public health and safety protocols
