Weather Characteristics and Tools

Weather

Characteristics and Tools

http://www.katrina.noaa.gov/images/katrina-08-28-2005.jpg

Characteristic Tool

Temperature Thermometer

Precipitation (Rain) Rain Gauge

Humidity Psychrometer

Pressure Barometer

Wind (speed/direction) Anemometer

Weather: Characteristics and Tools

Description

Thermometer

A thermometer measures heat energy. Temperature is measured in units called degrees. There are three different scales in use today. Fahrenheit is most commonly used in the united states. Celsius is the standard scientific unit all over the world. Kelvin is like Celsius, except zero is set at "absolute zero", where molecules are no longer moving.

Molecules of the liquid (mercury or alcohol) are sealed in a glass tube. The molecules of the liquid will move faster and spread out when they come into contact with something warm (transfer of energy through conduction). When the molecules spread out the liquid expands and moves up the tube.


Rain Gauge

A device that collects precipitation and allows us to measure the height of the water in the container.


Characterisitic: Humidity


Psychrometer

There are several types of hygrometers. One common type contains animal fibers, usually human hair, that stretch when the relative humidity increases and contract when it decreases. The fibers are usually attached to levers that turn the pointer on a dial.

The psychrometer, sometimes called the wet-and-dry bulb hygrometer, has two thermometers mounted side by side. The dry-bulb thermometer—measures the temperature of the air. The bulb of the other thermometer is covered with a cloth that is wetted and the water is then evaporate by whirling the psychrometer in the air. As the water evaporates, the bulb is cooled. In general, the drier the air, the greater is the drop in temperature. The relative humidity is determined by comparing the readings of the two thermometers with published psychrometric tables or charts.


Psychrometer


Barometer

Barometer, a device for measuring atmospheric pressure (the pressure resulting from the weight of the air above a given point). Because a change in atmospheric pressure is a sign of changing weather, this instrument is one of the chief tools of the weather forecaster. A falling" barometer, shows that a low-pressure mass of air is approaching usually bring storms. A rising" barometer generally means an approaching high-pressure air mass and fairer weather.


Weather Balloon


http://www.wrh.noaa.gov/vef/kids/wxballoon.php

Weather Satellites


http://www.weather.gov/sat_tab.php?image=ir

Doppler Radar


http://www.srh.noaa.gov/jetstream/doppler/how.htm

Weather Characteristics and Tools

Documents

Transcript of Weather Characteristics and Tools