SPI 0607.8.1 - Analyze data to identify events associated with heat convection in the atmosphere. SPI 0607.8.2 - Recognize the connection between the sun s energy and the wind.
o Energy from the Sun creates a convection current due to uneven heating on the Earth s surface. As the air is heated, it becomes less dense and rises. Cool air is denser, so it sinks. As the cool air sinks, it pushes the warm air up. The cool air is eventually heated by the Earth s surface and it begins to rise again. This creates a circular pattern. This movement of air caused by air pressure is called wind.
SPI 0607.8.3 - Describe how temperature differences in the ocean account for currents.
o Differences in temperature create ocean currents. Surface Currents are horizontal movement of ocean water that is caused by wind and that occurs at or near the ocean s surface. 3 factors that affect surface currents: 1. Global Winds 2. Coriolis Effect 3. Continental Deflection Deep Currents are stream-like movement of ocean water far below the surface 2 factors that affect deep currents: 1. Salinity 2. Temperature
o Warm currents from the equator begin to cool as they move toward the Pole. As the water cools, it becomes more dense, and it starts to sink. Cold water currents from the poles begin to warm up as they move toward the equator. As the water warms, it becomes less dense, and starts to rise to the surface. This movement creates convection currents in the ocean.
SPI 0607.8.4 - Interpret meteorological data to make predictions about the weather.
o Weather is the condition of the atmosphere at a certain time and place. Weather results from differences in pressure, heat, air movement, and humidity. The atmosphere is affected by the amount of water in the air. The amount of water vapor in the air is called humidity. The air's ability to hold water vapor changes as the temperature of the air changes. Relative humidity is the amount of water vapor in the air compared with the maximum amount of water vapor that the air can hold at a certain temperature.
A psychrometer is an instrument used to measure humidity. The higher the humidity, the more water vapor in the air. Precipitation is water, in solid or liquid form, that falls from the air to Earth. A tool used to measure air temperature is called a thermometer. Air pressure is the measure of the force with which air molecules push down on a surface. Air pressure increases the closer it gets to the Earth s surface.
Areas that have lower pressure than the surrounding areas do are called cyclones. Cyclones are areas where air masses come together, or converge, and rise. As the air rises, it cools and forms clouds and rain. Areas that have high pressure are called anticyclones. Anticyclones are areas where air moves apart, or diverges, and sinks. The sinking air is denser than the surrounding air, and the pressure is higher. As the air sinks, it warms up and absorbs moisture bring dry, clear weather.
o o o A barometer is an instrument used to measure air pressure. The greater the air pressure is, the higher the barometer will read. Barometric pressure is usually expressed in millibars A lower barometric reading shows that a lowpressure mass of air is approaching. Such lowpressure systems generally bring storms. A higher barometric reading generally means an approaching high-pressure air mass and fairer weather.
On a weather map, isobars are lines that connect points of equal air pressure. Isobars that form closed circles represent areas of high or low pressure. These areas are usually marked on a map with a capital H or L. Wind direction can be measured by using a windsock or a wind vane. An instrument used to measure wind speed is called an anemometer.
There are four types of weather fronts: Describe each front & Draw the symbol for each. 1. Cold Front: Cold air mass pushes under a warm air mass 2. Warm Front: Warm air mass moves over a cold air mass 3. Occluded Front: Warm air mass is caught between 2 cold air masses 4. Stationary Front: A cold air mass collides with a warm air mass, but there is not enough wind to force the cold air under the warm.