What gives snow its shape and color?
At higher altitudes, the lower the temperature, the higher the chance of snow. However, the exact temperature at which snow forms is not a fixed value because it depends on many different factors such as humidity, pressure, and air composition. But generally, when the temperature falls below freezing point (0°C), snow is likely to form.
Snow crystals come in a variety of beautiful shapes. They often have a polygonal chromatic structure with large snow blades and smaller crystal branches. Each snow crystal can have a different shape, but they are usually symmetrical and repeat a specific pattern. This is because the process of snow crystal formation occurs under specific atmospheric conditions and factors such as humidity, temperature, and pressure.
The white color of snow is due to a phenomenon called specular reflection. When sunlight strikes snow crystals, the light rays are reflected and scattered within the crystals. This process occurs many times in snow, resulting in the light being scattered in many different directions. As a result, we see snow as white, because white is a combination of all the wavelengths in the sunlight spectrum being reflected and scattered equally.
What criteria are used to classify storm levels?
Hurricanes are classified based on a variety of criteria, the two most important of which are wind speed and air pressure. The criteria commonly used as global standards for classifying hurricanes are:
Maximum Wind Speed: This is one of the most important factors in assessing the strength of a hurricane. Wind speed is measured in mph (miles per hour) or km/h (kilometers per hour). Hurricanes are classified into different categories based on their average maximum wind speed over a given period of time.
Minimum Air Pressure: The air pressure within a hurricane is also an important indicator of its strength. Air pressure is measured in hectopascals (hPa) or inches of mercury (inHg). Hurricane levels can be determined based on the minimum air pressure within the center of the hurricane.
Impact Level: A hurricane is also rated based on the potential impact on the affected areas. This includes the potential for flooding, high waves, heavy rain, and the potential for damage to people and property.
Size and structure: Hurricane categories can depend on the size of the storm and its internal structure. Factors such as the radius of the storm's high wind speed zone, the storm's low pressure zone, and cloud layering can also be considered in assessing hurricane category.
Hurricane rating and classification systems may vary depending on the country or organization responsible.
The most commonly used hurricane classification system is the Saffir-Simpson system, named after scientists Herbert Saffir and Robert Simpson. This system classifies hurricanes into five categories based on maximum wind speeds and potential destructive power. Here is a detailed description of the hurricane categories in the Saffir-Simpson system:
Category 1 - Mild Hurricane: Maximum wind speed: 74-95 mph (119-153 km/h). Minimum air pressure: > 980 hPa. Impact: Causes minor damage, such as downed trees, broken weatherboards, and significant damage to small boats.
Category 2 - Moderate Hurricane: Maximum wind speed: 96-110 mph (154-177 km/h). Minimum air pressure: 965-979 hPa. Impact: Causes significant damage to trees, homes and infrastructure. May damage roofs and pose a hazard to small boats.
Category 3 - Severe Hurricane: Maximum wind speed: 111-129 mph (178-208 km/h). Minimum air pressure: 945-964 hPa. Causes severe damage to civil structures, homes, and boats. Trees are broken, which can cause inland flooding and major damage to agriculture.
Category 4 - Severe Hurricane: Maximum wind speed: 130-156 mph (209-251 km/h). Minimum air pressure: 920-944 hPa. Impact: Causes severe damage to wind-resistant structures, homes, boats and infrastructure. Causes localized flooding and negative impacts on human life.
Category 5 - Severe Hurricane: Maximum wind speed: ≥ 157 mph (≥ 252 km/h). Minimum air pressure:
Why is there thunder, lightning, and lightning?
Lightning, thunder, and lightning are natural phenomena involving the generation and transmission of electromagnetic energy through the atmosphere.
- Thunder is the sound produced by a rapid reaction between electrical charges in the air. During a storm, particles in the clouds interact and create electrical charges in the cloud. When this charge becomes too strong, it can create a conduction path from the cloud to the ground. The polarization between these different areas of charge results in the development of a column of electricity from the cloud to the ground, called lightning. As the lightning travels through space, it heats the air around the conduction path and creates a structure of hot air that can produce a loud sound, called thunder.
- Lightning is a luminescent phenomenon in the air when a strong electric current passes through it. When a lightning rod moves between the clouds and the ground, the electromagnetic energy creates a small fire in the air around the electrical path. This fire creates a bright luminescent light, called a flash. Lightning occurs very quickly and usually lasts only a moment.
Both lightning and thunder are caused by natural electrical phenomena. As an electric charge travels through the air, it encounters resistance and creates a strong electric current. The conductive path creates the phenomena of thunder and lightning, and as the energy of the lightning travels through the air, it heats the surrounding air and creates sound and light.
To prevent the harmful effects of lightning on life, the following measures can be taken:
Avoid going outside during thunderstorms and lightning: When there is a thunderstorm warning or thunderstorm warning, stay indoors or out of your home, especially in open spaces such as golf courses, beaches, or grasslands. Seek shelter in a safe place such as a house, covered building, or car.
Avoid conductive objects: Avoid contact with conductive objects such as wires, utility poles, communication poles or large metal objects during thunderstorms and lightning. Electromagnetic fields from these objects can increase the risk of being struck by lightning.
Avoid dangerous locations: Avoid standing near high places such as treetops, power lines, bridge poles or mountain tops during thunder and lightning. This reduces the risk of being struck by lightning, as high places are more likely to attract lightning.
Find safe shelter: If you are caught in an open space without shelter, seek safety. Avoid lying or bending on the ground, as these are locations where lightning can conduct electricity.
Limit the use of electrical devices: During thunderstorms and lightning, limit the use of electrical devices such as cell phones, computers, music players or other digital devices. These devices can become contact points for lightning and cause danger.
Use of lightning protection systems: In buildings or structures, it is advisable to use appropriate lightning protection systems to reduce the risk of lightning strikes. This system includes lightning rods and a grounding system to safely route the lightning current into the ground.
Follow the weather forecast: Keep an eye on the weather forecast to know in advance about the possibility of thunder and lightning. When there is a storm warning or thunder and lightning weather, follow the instructions and recommendations from the authorities. This will help you be better prepared and avoid unnecessary danger.
Learn CPR: Master the basics of CPR in case someone is struck by lightning. Knowing how to perform CPR and use an AED can save the life of someone struck by lightning in an emergency.
Install a grounding system: In homes and buildings, a grounding system should be installed to reduce the risk of lightning strikes and limit the damage caused. The grounding system will safely route the current from lightning to the ground.
Know the safety information: Learn and understand the safety rules about lightning, thunder, and lightning. Learn about the safety principles during storms or weather with thunder and lightning. Provide your family and those around you with this safety knowledge so that together you can be prepared for the harmful effects of lightning.
While it is impossible to completely eliminate the risk, taking precautions can reduce the risk of being struck by lightning and keep lives safer. At the same time, always pay attention to government agencies and weather experts for accurate information and timely guidance.
Source: https://daidoanket.vn/thac-mac-quanh-ta-ky-6-10292882.html
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