Weather and Climate

Weather Temporary behavior of atmosphere (what’s going on at any certain time) Temperature is one of the basic elements of weather. Temperature is the measurement of how warm or cold it is outside. The wind is the movement of air across Earth's surface. The daily measure of humidity and precipitation Today satellites in space collect weather information worldwide. Computers help meteorologists to track weather patterns and to make weather forecasts, or predictions.

Climate Climate is the long term average precipitation and temperature of an area (30 - 1,000,000 years). large Climate is determined by global wind patterns, latitude, altitude and ocean currents over a large geographic area. veryslow Climate is very slow to change.

What factors affect weather & climate? 1. The Sun 2. The Water Cycle 3. The Atmosphere 4. The Ocean

What are the characteristics of weather? Atmospheric conditions including air temperature, air masses, and air pressure Wind speed and direction The amount of moisture in the air called humidity. Warm air can hold more moisture than cold air can. Precipitation may come in many forms, including rain, hail, sleet, and snow. The form precipitation takes depends on other weather conditions, such as temperature.

Air Temperature Warm Air- light in weight so it rises up Cold Air- heavy in weight so it sinks

Air Masses Courtesy of Aviation Digital Data Service (ADDS) Will the weather in Dallas on Sunday be colder or warmer? = body of air with a certain temperature and moisture level can be warm or cold can contain a lot of moisture or not a lot of moisture The weather will be cooler since a cold front moved through Dallas on Saturday.

How does air pressure affect weather? how much the earth’s atmosphere is pressing down on us measured with a BAROMETER if it CHANGES, then new weather is on the way: Falling Air Pressure = stormy weather coming Rising Air Pressure = fair weather coming Steady Air Pressure = no change is coming

Relative Humidity It is controlled by temperature. It is controlled by temperature. Air is like a sponge, and can only hold so much water. Warm Warm air holds more moisture than cool air (more space for water vapor between air molecules). warms decreases. As air warms, relative humidity decreases. cools increases. As air cools, relative humidity increases.

Direction and Speed Wind speed is measured by anemometers. Wind direction is measured by wind vanes. Wind is air in motion.

How does the sun affect weather? It warms the atmosphere & oceans. It creates climate zones. It powers the water cycle. It affects weather patterns.

What causes wind? The Sun does!

As the sun heats the Earth... the Earth heats the air above it.

Warm air rises Cool air sinks

The sun also heats land and water at different rates. The difference in temperature between the land and water also causes wind.

Ocean Currents Affect Climate Differences in water temperature, winds and the rotation of the earth create currents. Pidwirny, M. (2006). "Surface and Subsurface Ocean Currents: Ocean Current Map“. Fundamentals of Physical Geography, 2nd Edition. Date Viewed.

How do we know about past climates? Tree Rings – growth is controlled by temperature, precipitation and sunlight Pollens – give a good indication of what was living at the time indicating a temperature range Ice and sea bed cores The fossil record Coral beds

How are climate and weather similar and different? short term Weather is the short term measure of temperature, humidity, precipitation, cloudiness, brightness, visibility, wind, and atmospheric pressure. Weather can change from minute-to-minute, hour-to-hour, day-to- day, and season-to- season. long term. Climate is long term. Climate is the average of weather patterns over many years for a particular region. Climate is determined by global wind patterns, latitude, altitude and ocean currents.