5 .- Meteorology
5.1 .- Importance of Time. Barometer.
Importance of weather on safety of navigation or meteorological weather directly affects the state of wind and sea, factors affecting vessel, with the consequent risk of your safety and the crew unless we take appropriate measures . It is therefore necessary before heading out to sail to gather information on the weather.
Definition of atmospheric pressure: the weight of air above the Earth, as a result of the attraction of the earth on the mass of air that surrounds it. Pressure is a fundamental variable that have meteorologists for weather forecasting.
Measurement of atmospheric pressure: atmospheric pressure is usually measured in millimeters, inches or millibars atmospheres.
Sea level pressure: normal pressure at sea level is 760 mm = 1013.2 millibars = 1 atmosphere.
Barometer: is the instrument for measuring atmospheric pressure. There are two types of barometers: mercury based on the experiment Torrecelli not used in sailing, and those based on expansion and contraction of tubes or empty capsules are called aneroid barometers.
Measurement of atmospheric pressure with the aneroid barometer: This type of barometer can consist of curved Bourdon tube (disused) or glass capsule base. This barometer is divided into three parts: the body senses or capsule (basically closed metal boxes corrugated surface to which it has practiced the partial vacuum), the amplifier and the needle mechanism and indicator scale. The indicator needle or scale indicates pressure in millimeters, inches or millibars. The conversion between these measures is:
· 1 mm = 1.33 mbar = 0.039 "
· 1 millibar = 0.75 mm = 0.029 "
· 1 "= 25.4 mm = 33.86 millibars
Barograph: it is an aneroid barometer with a pen that records the pressure variations on a cylinder that rotates driven by a clockwork.
5.2 .- isobaric lines. Depressions and anticyclones.
Isobaric lines: maps of weather information lines are drawn with the same atmospheric pressure are called isobars. These are shown with a spacing of 4 millibars. The normal average pressure of these maps take the normal pressure at sea level as a base (760 mm? 1012 mb), considering the high and low pressures that exceed or fall short of this value.
Squalls: The centers of low pressure are called depressions. Are indicated in the letter with the letter B. Almost always mobile. Usually correspond with cloudiness and precipitation.
Anticyclones: the centers of high pressure called anticyclones. Are indicated in the letter with the letter A. They can be fixed or mobile. The fixed favor the formation of fog by temperature difference with the adjacent layers. The motives are usually between two storms going with them.
And wind circulation in the northern hemisphere in these configurations:
• In the cyclone the wind circulates clockwise (clockwise clock) and centrifugal (outward) in the northern hemisphere. Rotates counterclockwise in the Southern Hemisphere.
• In the stormy wind circulates counterclockwise (counterclockwise clockwise) and centripetal (inward) in the northern hemisphere. Rotates clockwise in the Southern Hemisphere.
Buys Ballot Law: There is a simple and practical way of locating low pressure. By facing the wind, the low pressure center will be between 90 º and 135 º clockwise in the Northern Hemisphere (and clockwise in the Southern Hemisphere). Sometimes this rule is expressed by placing the observer of shoveling the wind.
Tracks of storms: in general in the northern hemisphere storms moving from W to E. In the Iberian Peninsula is often directed towards ENE, but depends on the situation and strength of the next cyclone that may affect them.
5.3 .- Wind
The wind is moving air. This movement occurs because the air, when heated, expands and becomes more volume so that its density decreases. A greater density equals higher pressure and lower pressure lower density, then the air is displaced from the nuclei of high pressure to low.
Wind direction: indicated by the place you came from or the wind blows.
True wind: for wind there when the ship is stopped we will notice the true wind.
Apparent wind: to be sailing the wind will notice shall be made true wind, if any, caused by wind and boat speed.
Rolar: varianción of wind direction on.
Contrast: sudden change of wind to the opposite side which was blowing and then takes great violence generally.
Caer: wind strength decreases.
Refresh: the wind increases its strength.
Gust: brief, intense increase of wind speed.
Gust: Change the intensity and wind strength during intervals, usually short.
Calmar: Decrease the force of wind or sea, in whole or in part.
Recalm: sudden, momentary decrease of force wind to continue later with the previous intensity.
5.4 .- coastal Brisas
Coastal breeze: weak local winds are blowing on the coast. They arise due to the thermal differences of seawater and the surface of the earth.
Terral: they occur at night, the earth loses heat faster than the sea, so that cold air will land on something warmer and the sea. This produces a small pressure gradient will produce a breeze that runs from land to sea. These winds, depending on the terrain, being felt up to 20 'offshore.
Virazón: occur during the day, the earth gains heat more rapidly than the sea, which will be hot air over the tier and somewhat cooler on the sea. This produces a small pressure gradient will produce a sea breeze to land.
5.5 .- Measurement of wind
Beaufort Scale: scale for measuring wind force, initially created by Admiral Sir Francis Beaufort and used internationally.
Beaufort Scale - wind intensity GradoDenominaciónVelocidad Speed knots km / h Aspecto0Calma <1 <2The Sea like a mirror. 1Ventolina 1-32-6The sea begins to curl. 2Flojito (breeze) 4-67-11Olas small to reach break. 3Flojo (breeze) 7-1012-19Olas crests begin to break. Fleece dispersed.4Bonacible (breeze) 11-1620-30Olas a bit long. Many fleece. 5Fresquito (Cool Breeze) 17-2131-39Olas moderate and long. Abundance of fleece plus any spray. 6Fresco (strong breeze) 22-2740-50Comienza the formation of large waves. The white foam crests are everywhere. Increase the spray and the navigation is dangerous for small boats. 7Frescachón (Strong Wind) 28-3351-61La foam is blown in the wind. The sea is thick. 8Temporal (hard Wind) 34-4062-74Olas high with breakers. The foam is blown in white clouds. 9Temporal Strong (Very Hard) 41-4775-87Olas very thick. The foam is blown in dense layers. The sea began to roar. The spray hinder visibility. 10Temporal Drive (Temporary) 48-5588-102Olas very thick with plumed crests. The surface of the sea looks white. Reduced visibility. The sea roars. 11Temporal Very Hard (Borrasca) 56-63103-117Olas exceptionally large (medium tonnage ships out of sight). Sea completely white. Visibility very low. The navigation becomes impossible. 12Temporal hurricanes (Hurricane) 64-71> 118-123> The air is filled with foam and spray. The visibility is almost zero. All navigation is impossible.
Wind: device used to measure the wind speed. There are two classes of travel (with cups or propellers) and pressure. The speed is indicated by the anemometer is the apparent wind.
Weathervanes: A device to indicate wind direction. The vane consists of a horizontal axis that pivots on a vertical one. The vane usually has an arrow where the rear in the form of vertical plate offers more resistance to wind than the previous one to be easily east wind.
Vane: A device to indicate wind direction. The vane consists of a sleeve of tissue are elongated conical, open at both ends and is guided by the wind.
Burgee and grimpolón: the pennant is a long triangular pennant. that is guided by the wind. The grimpolón is narrower, more elongated than the pennant.
5.6 .- Sea state
Douglas sea scale: scale for measuring sea state, created by Sir Henry Percy vicealmirnate Douglas.
Douglas Scale - Scale GradoDenominaciónAlturaDescripciónEquivalencia sea state Beaufort0Calma 0 metrosLa Sea like a curly espejo.0 Mar 1Rizada 0-0.2 with small ridges without espuma1-2 2Marejadilla 0.2-0.5 Small waves whose crests begin to romper3 3Marejada 0.5 Small waves breaking -1.25. Frequent form borreguillos.4 4Fuerte Olas Surf 1.25-2.5 moderate elongated. They form many borreguillos.5 5Gruesa 2,5-4SE form large waves with white foam crests partes6 6Muy all 4-6The Thick sea begins to pile up and the white foam crests are driven viento.7 7Arbolada 6-9Olas high. Dense foam strips in the direction of the wind and the sea begins to break. The spray makes the visibilidad.8-9 8Montañosa 9-14Olas very high long-crested waves. The foam is in great masses in the wind direction and sea surface appears almost white. The waves break suddenly and heavily. Low visibilidad.10-11 9Enorme> 14The air is filled with foam and water spray. Sea completely white. Visibility virtually nula.12Elements involved in the state of the sea: the sea up by the wind is a function of three variables: intensity, persistence and fetch.
Intensity: strength of the wind or the speed that this has. This is a key factor, but has to be complemented by the persistence and fetch for the creation of waves.
Persistence: The number of hours the wind has blown in the same direction and with the same intensity. The higher the sea can be more persistent form.
Fetch: the area or extent to which the wind blows in the same direction and with the same intensity. The greater the fetch area the greater the wave height.
5.7 .- Temperature
Concept of temperature: in meteorology is the state of heat in the atmosphere. It spreads by convection (vertical rise of the heat) and advection (transport of heat by horizontal air currents).
Isotherms: lines that connect isotherms are, at one time and a given height, the points have the same temperature.
Measuring temperature: the thermometer is used, based on the physical properties of bodies under the influence of heat: expansion of a liquid, an electrical resistance variation, variation of gas pressure, etc..
Measuring temperature with mercury thermometer: The most common thermometers consist of a glass capillary tube, to which you have had a vacuum, spread in one end where the mercury is deposited. Mercury expands and contracts by the glass capillary tube on a scale showing the temperature there at that time.
Centigrade scale (C °) or Celsius, is used in thermometers that we use regularly. This scale determines the melting point of distilled water on ice is 0 ° and the boiling point of distilled water is 100 º.
Fahrenheit scale (° F) is another measurement scale is quite common Anglo-Saxon countries. The correspondence with the Fahrenheit scale is calculated using these formulas: C ° = (F ° -32) * (5 / 9) and F ° = (C ° * (9 / 5)) +32.
5.8 .- Weather
Newsletters: The National Meteorological Institute provides short-term parties includes in this order:
General situation and trends ·
· Information from coastal stations
These newsletters relate to coastal areas which are detailed:
· Costa de Galicia
· Coast Basque Country, Cantabria and Asturias
· Costa de Catalunya
· Costs of the Balearic Islands
· Costa de Murcia and Valencia
· Costa de Andalucía Oriental, Melilla and Alboran
· Coast Western Andalusia and Ceuta
· Coasts of the Canary Islands
How to get it: the parts can be obtained at:
· VHF: The Maritime Rescue Co-ordination Centers and coastal VHF stations transmit weather bulletins for coastal areas, following announcement on channel 16.
· Teletiempo sea: the phone is available the parties at the following numbers:
807 170 370: Information Balearic coastal and high seas to the Mediterranean.
807 170 371: Information coastal provinces along the Mediterranean coast and the Mediterranean sea.
or 807 170 372: Information for the Cantabrian coast coastal and Galician.
or 807 170 373: Information for the Andalusian coast coastal West and Islands.
or 807 170 374: Data for the Atlantic sea
· Internet: http://www.inm.es
· Clubs Nautical and Marinas provide weather information from Coastal Meteorological Centers.
Storm warnings: on VHF channel 16 are issued gale warnings, after periods of silence before the call lists.
Forecast with barometer and thermometer: it is very difficult to make reliable predictions of the time with the barometer and thermometer on board. However, can provide guidance if we analyze its trend over time, especially Barometer:
• In general, the ups and downs correspond respectively to trends to improve and worsen over time reintante.
· Rises slow and gentle (less than 0.4 mm per hour) indicate lasting tendency to improve with moderate winds.
· Severe and rapid rises (more than 0.6 to 1 mm per hour) often correspond with high winds, rain showers and isolated.
· The slopes slow and gentle (less than 0.4 mm per hour) indicate a tendency to worsen in the long term and with moderate winds.
· Descents accused and fast (more than 0.6 to 1 mm per hour) often correspond with high winds, squalls and heavy rainfall.
§ The pressure is kept fixed (no change for five or six hours), time constant.
Objservación barometer and thermometer:
· Pressure rises, low temperature: progress tendendencia anticyclonic and improve.
· Low pressure, temperature rises: storm and tendendencia situation worse.
Showers: it is a short-term weather event, which begins and ends abruptly, can be wind, water, snow, etc.. The low, dark clouds in clusters or cumuloninbos are commonly provided with little time and a short distance.
Partly cloudy wind: they are sudden and abrupt changes of intensity and wind direction that occur when passing clouds.
Showers of rain: they occur, like the wind, but with the unloading of heavy rain.
Evidence: the observation of the sky can get some clues about how time might behave in the coming hours.
6.1 .- Definitions.
Telecommunications means any transmission or reception of signs, signals, writing, images, sounds or intelligence of any nature by wire, radio, optical or other electromagnetic systems.
Radio: All communication through radio waves.
Radio waves: are electromagnetic waves whose frequency is less than 3,000 GHzs which propagate in space. Also called Hertzian waves.
Radio: communications device via radio waves.
Telephone: telecommunications system for transmission of speech or, in some cases, other sounds.
Station: One or more transmitters or receivers necessary to ensure a radiocommunication service.
Ski boat: maritime mobile service station on board a ship, destined to be used while in motion.
Coast Station: a ground station of the maritime mobile service.
Maritime Mobile Service: mobile service between coast stations and ship stations or between ship stations.
VHF set of frequencies between 30 and 300 MHz commonly used on recreational craft with a range of 10 to 25 miles between ships and between 25 and 45 miles between ships and land stations. It is issued with the powers of 1 and 25 w.
Simplex: transmitter and receiver alternately speak and listen.
Duplex: transmitter and receiver speak and listen simultaneously.
Half-duplex: a transmitter / receiver simplex and a transmitter / receiver duplex.
Communications: make only those that are necessary towards making it as short as possible, made with clarity and following the rules and procedures.
Completion of a transfer: the end of the work between two stations is indicated by the word "finished" (or if there ALFA VICTOR language problems).
Importance of not overloading the channels with useless transmissions are prohibited from broadcasting stations all useless.
Authority pattern: the service of a mobile station under the authority of the ship: Captain, Master, or person responsible for the boat. Anyone who knows the existence or content of a message are required to store and guarantee the secrecy of the communication.
6.2 .- Discipline in the use of radio
It is prohibited to all stations:
· Useless transmissions.
· The transmission without identification or false identification.
· Transmissions ether vallan not aimed at a station.
· Transmissions within port and roads in the frequency range of 1,670 Khz to 2850 Khz, except in cases of distress, urgency and safety.
Consideration should be given power emission limit to a minimum to ensure a satisfactory service.
Transmissions unmarked and identification: each station is identified by the call sign or any other means of identification (name of station, location of the same, registration, etc.).. Transmissions can not be made if you have not been identified in some of the ways.
6.3 .- procedure link
Calling Channel and working conditions:
With ship stations: the calling frequency is 2182 kHz or channel 16 (156.80 Mhz). The working channel is anyone not assigned to a specific use.
Among ships: the calling frequency is 2182 kHz or channel 16 (156.80 Mhz). The working channel is anyone not assigned to a specific use.
Yacht clubs: the call channel and work is 9 VHF
In the 2182 kHz frequency and channel 16 (156.80 Mhz) calls should not exceed one minute.
Call (in the call channel) · Identification Call sign of station (maximum 3 times) • The word "here" (or DELTA ECHO if language problems) · Call sign identifying the calling station (maximum 3 times). Repeating the call
- It can be repeated 3 times with intervals of 2 minutes and suspend the call. · If still no response can be repeated at intervals of 3 minutes. Reception (on the call channel) · Call sign of station identification call (up to 3 times, once VHF) • The word "here" (or DELTA ECHO if language problems) · Identification Call sign of station (maximum 3 times, twice VHF). · It down the working channel for who directs traffic. defer the receipt (in the call channel) Wait ... minutes (or ALFA SIERRA if there are problems of language.) Conversation (in the working channel) · is performed in the working channel · alternatively be notified each of the seasons, ending with "Over and Out" (or ROMEO or KILO if language problems). • The identifier of the stations, if used, will be made only once. Termination (in the working channel) · is indicated by the word "Done" (or if ALFA VICTOR There are language problems). address traffic · Among boats: they initiated the call directs traffic. · ground stations: the land station directs traffic. 6.4 .- distress, urgency and safety
· Are held to ether, ie who will listen.
· When you have doubts about the understanding of language phonetic alphabet is used.
· Can only be made with the permission of the Patron.
· Once the danger you have to communicate this fact.
· These communications have priority over any other.
Cause: The boat and / or its crew are in grave and imminent danger and requests immediate assistance. Priority: takes precedence over any other type of call. Signal: Two-Tone (1,300 and 2,200 cycles) of 250 milliseconds each for 30 to 60 seconds. Call:
- MAYDAY MAYDAY MAYDAY (pronounced Medea).
6.5 .- Special Services
Radio doctor is a service of free medical advice and assistance to all personnel on board ships at sea.
Notices to Mariners: coastal stations broadcast warnings from the naval authorities with useful information for navigation: gale warnings, changes to lighthouses, buoys, wrecks, floating objects, etc..
Weather reports: the coastal stations broadcast weather reports, from the Area Meteorological Centers or the National Institute of Meteorology.
Radio Conference: you can apply to the coastal station to contact the number indicated.
VHF Obligation in the navigation area "C" as indicated in the safety equipment for this category (as amended by FOM/1144/2OO3 order, where no material is included as a mandatory safety and refers to Maritime Radio provisions in force).
Requirement for communications equipment are approved: by the Directorate General of Merchant Marine.