Upload
matilda-goodman
View
224
Download
0
Embed Size (px)
DESCRIPTION
Weather Instruments We are our own weather station at sea. We must develop an accurate forecast using data received from shore and that we collect ourselves. You’ll learn how to make a forecast in Meteorology.
Citation preview
Navigation
NAU 102
Lesson 32
Weather Instruments
The safety of crew, passengers, cargo and the ship itself is dependent on making good weather decisions.
Weather has a significant impact on every voyage.
Weather Instruments
We are our own weather station at sea.
We must develop an accurate forecast using data received from
shore and that we collect ourselves.
You’ll learn how to make a forecast in Meteorology.
Duties of the Mate
At all times, be knowledgeable of the current weather.
•Wind direction and speed•Wave direction and height
•Visibility•Trend of the barometer
Duties of the Mate
At all times, be knowledgeable of the weather forecast.
•Obtain 24 hour forecast from weather fax, messages, etc.
•Interpret the forecast for your area.•When necessary, make your own
forecast.
Weather Instruments
Satellites
Meteorological data is collected by:
Buoys
Ships (that’s you)
Duties of the Mate
Conduct marine surface weather observations.
•Make observations•Log observations
•Transmit observations to National Weather Service
Duties of the Mate
Conduct marine surface weather observations.
4 times each day
0000, 0600, 1200, 1800 GMT
Voluntary program
7000+ ships worldwide (600 US)
Weather Observations
Data is collected and formatted in
accordance with the Marine Observer’s
Handbook.
http://www.nws.noaa.gov/om/marine/handbk1.pdf
Weather Instruments
Aneroid Barometer
Measures atmospheric pressure.
Air pressure exerts a crushing force on a thin metal element.
Linkages move to a pointer to indicate the pressure on a scale.
Aneroid Barometer
Aneroid Barometer
Must be properly adjusted.(Usually done by a professional, often for free.)
Reading must be adjusted for elevation to give pressure at sea level.
(Note: Mercurial Barometers must also be corrected for latitude and temperature.)
Barometers
Weather Instruments
Barograph
A recording barometer.
Weather Instruments
Thermometer
Measures air temperature.
You must be able to convert between
Celsius and Fahrenheit scales.
Temperature Conversions
Temperature Conversions
Weather Instruments
Hygrometer
Measures Relative Humidity and Dew Point.
Weather Instruments
Relative Humidity – ratio of amount of water vapor in the air to the
amount it could hold at the current temperature.
Dew Point – the temperature at which water vapor will condense.
Weather Instruments
Hygrometer
Most common type: sling psychrometer.
Sling Psychrometer
Two Thermometers: 1 wet, 1 dry
Temperature difference is noted.
Sling Psychrometer
Psychrometer
Introduction to Navigation
Questions?