UNIT 1: Weather Dynamics Chapter 1: Inquiring about Weather Chapter 2: Weather Forecasting

Chapter 1: Inquiring about Weather UNIT 1 Chapter 1: Inquiring about Weather Chapter 1: Inquiring about Weather Severe weather comes to Nova Scotia in the form of snow, fog, freezing rain, hail, heavy rain, or strong winds. These weather events can trigger flooding and storm surges that affect the whole province. Describe a severe weather event that you have experienced. Is it important to study weather? Why or why not? Students may recall experiences thunderstorms, blizzards, hurricanes, tornados, or tropical storms. Knowledge of weather helps in advance preparations for severe weather, which saves property and lives. In the long term, it helps with planning communities and seasonal activities such as fishing, agriculture, or recreation.

1.1 The Atmosphere: Energy Transfer and Properties UNIT 1 Chapter 1: Inquiring about Weather Section 1.1 1.1 The Atmosphere: Energy Transfer and Properties Weather is the physical conditions of the atmosphere at a specific time and place. Weather changes constantly. Weather varies from place to place. Weather is closely monitored. How are daily weather forecasts beneficial? TO PREVIOUS SLIDE

1.1 The Atmosphere: Energy Transfer and Properties UNIT 1 Chapter 1: Inquiring about Weather Section 1.1 1.1 The Atmosphere: Energy Transfer and Properties Each of these weather components can affect activities or situations. For each component, describe how an activity or situation might require knowledge of the conditions. TO PREVIOUS SLIDE

Factors Affecting Absorption of Energy UNIT 1 Chapter 1: Inquiring about Weather Section 1.1 Factors Affecting Absorption of Energy Different substances absorb energy at different rates. The property of a substance that involves how a substance absorbs and releases energy (and how quickly) is called its specific heat capacity. Water has a high specific heat capacity. Water heats up and cools off more slowly than land does. Both water and land heat up and cool off more slowly than air does. Water is a heat sink. A heat sink is any substance that can absorb and retain energy without changing state. TO PREVIOUS SLIDE

Keeping in the Heat UNIT 1 Chapter 1: Inquiring about Weather Section 1.1 Keeping in the Heat Why doesn’t thermal energy radiate into space at night? The greenhouse gases act as a heat sink. They absorb thermal energy and radiate the energy in all directions. These gases cause the troposphere—where weather occurs—to retain more heat than it would if these gases were not present. What can occur when the atmosphere contains more greenhouse gases than normal? The atmosphere can absorb more thermal energy than normal causing the temperatures on Earth to rise. TO PREVIOUS SLIDE

Thermal Energy Transfer by Conduction, Convection, and Radiation UNIT 1 Chapter 1: Inquiring about Weather Section 1.1 Thermal Energy Transfer by Conduction, Convection, and Radiation Thermal energy is transferred from a warmer object to a cooler object, and it is transferred in three ways. Radiation is the transfer of thermal energy by electromagnetic waves. Conduction is the transfer of thermal energy between two objects or substances that are in direct contact. Convection is the transfer of thermal energy by the movement of heated material (liquids or gases) from one place to another. TO PREVIOUS SLIDE Continued…

Thermal Energy Transfer by Conduction, Convection, and Radiation UNIT 1 Chapter 1: Inquiring about Weather Section 1.1 Thermal Energy Transfer by Conduction, Convection, and Radiation TO PREVIOUS SLIDE

Atmospheric Pressure UNIT 1 Chapter 1: Inquiring about Weather Section 1.1 Atmospheric Pressure At sea level, the atmospheric pressure is about 101.3 kPa. As altitude increases, atmospheric pressure decreases. As altitude increases, temperature decreases. As altitude increases, the density of the atmosphere also decreases. How would the changes in altitude, temperature, density, and atmospheric pressure affect a mountain climber on the peak of Mount Everest? Atmospheric pressure is the pressure exerted by air particles above any point on Earth’s surface. A climber will have difficulty breathing because atmospheric pressure and air density are lower at higher altitudes. The climber will also be cold because the temperature is lower. TO PREVIOUS SLIDE

Atmospheric Pressure UNIT 1 Chapter 1: Inquiring about Weather Section 1.1 Atmospheric Pressure Meteorologists—scientists who study weather– use atmospheric pressure readings to predict changes in the weather. A decrease in atmospheric pressure suggests that warm, humid air is approaching and that the temperature will increase. An increase in atmospheric pressure suggests that cool, dry weather is approaching. Humidity is a measurement that describes the amount of water vapour in air. The air becomes saturated when the specific humidity equals the capacity of air to hold water at a specific temperature, known as the dew point. TO PREVIOUS SLIDE

The Role of Water in Transferring Energy in the Atmosphere UNIT 1 Chapter 1: Inquiring about Weather Section 1.1 The Role of Water in Transferring Energy in the Atmosphere Because of water’s high specific heat capacity, a lot of energy is needed to change the temperature of water. Oceans and lakes have a moderating effect on air temperature for nearby land because of water’s high specific heat capacity. Thermal energy is in the form of kinetic energy, or movement of the particles, and potential energy, or the intermolecular attractions, between the particles. Where is the thermal energy stored in water molecules? TO PREVIOUS SLIDE

UNIT 1 Chapter 1: Inquiring about Weather Section 1.1 Section 1.1 Review Weather refers to physical conditions of the atmosphere at a specific time and place. The vast amount of water on Earth acts as a heat sink that has a significant influence on temperature. Radiation, conduction, and convection transfer thermal energy through the atmosphere. Atmospheric pressure decreases as altitude, temperature, and humidity increase. Changes in the state of water involve absorption and release of thermal energy. TO PREVIOUS SLIDE