MRI 2313 MARITIME GEOGRAPHY

CHAPTER 2: METEOROLOGICAL AND

OCEANOGRAPHIC

LEARNING OUTCOME

Introduction to meteorology Introduction to oceanographic Basic meteorological instrument Factors affecting shipping and transport

Introduction to meteorology

Definition

Meteorology The study of the processes and phenomena of

the atmosphere, especially as a means of weather forecasting.

Weather The state of the atmosphere at a place and

time regards temperature, wind, rain, etc. (concise oxford dictionary, 2011)

Climate The general weather conditions prevailing in an

area over a long period.

Meteorology

The study of the atmosphere, atmospheric phenomena and atmospheric effects on our weather.

Gravity keeps the atmosphere from expanding much farther.

Atmosphere

It reaches over 560 km (348 miles) from the surface of the earth.

There is no exact place where the atmosphere ends;

It just gets thinner and thinner, until it merges with outer space.

The composition

It is primarily composed of nitrogen (78%) and oxygen (21%) with only small concentrations of other trace gases. Nearly all atmospheric water vapour or moisture is found in the troposphere, so it is the layer where most of Earth's weather takes place

Atmosphere

Pressure layers

Layers of the atmosphere

Troposhere Lowest atmospheric layer and is about

seven miles (11 km) thick. Most clouds and weather are found in the

troposphere contains most of the water vapor)

It is thinner at the poles (averaging about 8km thick) and thicker at the equator (averaging about 16km thick).

The temperature decreases with altitude

Stratosphere The stratosphere is found from about 7 to

30 miles (11-48 kilometers) above the Earth’s surface.

In this region of the atmosphere is the ozone layer, which absorbs most of the harmful ultraviolet radiation from the Sun (dangerous to plant and animal life).

The temperature increases slightly with altitude in the stratosphere. The highest temperature in this region is about 32 degrees Fahrenheit or 0 degrees Celsius.

Layers of the atmosphere

Mesosphere Above the stratosphere 50 km – 80 km above earth’s surface Rarefield, thin, and the temperature is

decreasing with altitude, about -130 Fahrenheit (-90 Celsius) at the top

Layers of the atmosphere

Thermosphere Starts at about 55 km. Temperature quite hot; here the

temperature is not measured using a thermometer, but by looking at the motion and speed of the affect a thermometer.

Temperature may be as high as thousands of degree.

Layers of the atmosphere

Exosphere Region beyond the thermosphere

Ionosphere The ionosphere overlaps the other

atmospheric layers, from above the Earth. The air is ionized by the Sun’s ultraviolet light. These ionized layers affect the transmittance and reflectance of radio waves. Different ionosphere layers are the D, E (Heaviside-Kennelly), and F (Appleton) regions.

Layers of the atmosphere

Lightning can generate whistlers, radio waves that can travel long distances.

Very high frequency radio waves (VHF) can travel through the atmosphere to and from satellites and are used for communication. The airglow is due to a chemical reaction in the upper atmosphere that emits light.

Many radio waves are reflected at night by the ionosphere making it possible to hear AM radio and shortwave radio stations that are far away.

Gamma rays and x-rays are absorbed by the upper atmosphere; visible light can penetrate to sea level.

Many infrared wavelengths can also pass through the atmosphere.

Introduction to oceanography

Oceanography Study of the ocean, with emphasis on its character as an

environment. The goal is to obtain a description sufficiently quantitative to be used for predicting the future with some uncertainty.

Geophysics Study of the physics of the earth

Physical oceanography Study of the physical properties and dynamics of the

ocean. The primary interests are the interaction of the ocean with the atmosphere, the oceanic heat budget, water mass formation, currents and coastal dynamics. It is considered by many to be subdiscipline of geophysics.

What is oceanography?

The branch of science concerned with the physical and biological properties and phenomena of the sea. (Oxford Dictionary)

Sea: The expanse of salt water that covers most of

the earth’s surface and surrounds its land masses. Example: South China Sea, Black Sea.

Ocean: A very large expanse of sea; in particular, each

of the Atlantic, Pacific, Indian, Arctic, and Antarctic Oceans.

Ocean

An ocean is a body of saline water that composes much of a planet's hydrosphere, occupying more than two-thirds of Earth's surface

Hydrosphere: the combined mass of water found on, under, and over the surface of a planet.

Ocean contains 97% of the Earth's water Major divisions of the World Ocean – the Pacific,

Atlantic, Indian, Antarctic (Southern Ocean), and Arctic Oceans

Arctic ocean

Located in the Northern Hemisphere and mostly in the Arctic north polar region, is the smallest and shallowest of the world's five major oceanic divisions.

The northernmost part of the World Ocean.

Almost completely surrounded by Eurasia and North America

Partly covered by sea ice throughout the year (and almost completely in winter).

Pacific ocean

The largest division of the World Ocean, 165.25 million square kilometers in area

Covers about 46% of the Earth's water surface and about one third of its total surface area, making it larger than all of the Earth's land area combined.

It extends from the Arctic in the north to the Antarctica in the south, bounded by Asia and Australia in the west, and the Americas in the east.

The equator subdivides it into the North Pacific Ocean and South Pacific Ocean,

The Mariana Trench in the western North Pacific is the deepest point in the world, reaching a depth of 10,911 metres

Atlantic ocean

The world's second largest ocean. Total area of about 106,400,000 square kilometres. Covers approximately 20 percent of the Earth‘

surface and about 29 percent of its water surface area.

Atlantic Ocean occupies an elongated, S-shaped basin extending longitudinally between Eurasia and Africa to the east, and the Americas to the west.

The equator subdivides it into the North Atlantic Ocean and South Atlantic Ocean.

Indian ocean

The third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface.

It is bounded by Asia—including India, after which the ocean is named on the north, on the west by Africa, on the east by Australia, and on the south by the Southern Ocean (Antarctica).

Area is 73556000 km², including the Red Sea and the Persian Gulf.

Southern ocean (Antarctic ocean) The Southern Ocean comprises the

southernmost waters of the World Ocean.

Generally south of 60°S latitude and encircling Antarctica.

The fourth-largest Ocean.

South China Sea

Is a marginal sea that is part of the Pacific Ocean

Encompassing an area from the Singapore and Malacca Straits to the Strait of Taiwan of around 3,500,000 km square

Importance area due to one-third of the world's shipping transiting through its waters, and believed to hold huge oil and gas reserves beneath its seabed.

It is located: South of mainland China and the island of

Taiwan, West of the Philippines, North west of Sabah (Malaysia), Sarawak

(Malaysia) and Brunei, North of Indonesia, North east of the Malay peninsula

(Malaysia) and Singapore, and East of Vietnam.

South China Sea

Ocean basin

Ocean basins are large geologic basins that are below sea level.

The geomorphologic features such as the continental shelves, the deep ocean trenches and the undersea mountain ranges (for example, the mid-Atlantic ridge)

Ocean basin

An oceanic basin covered by seawater Ocean basins are large basins below sea level There are under sea features;

Continental shelves Deep ocean trenches Undersea mountain ranges

There are complement to the continents, with erosion

Sediments derived ending up in the ocean basins Most ocean basins as basaltic plains, than as

sedimentary depositories

Basins are both above and below sea level; Maracaibo Basin in Venezuela

Oceans cover 71.11% of the Earth's surface. Oceans lie lower than continents, the former

serve as sedimentary basins. Is serve as repositories for the skeletons

of carbonate- and silica-secreting organisms; coral reefs Diatoms Radiolarian foraminifera.

Oceanic basin  actively changing size /relatively, tectonically inactive, depending on whether there is a moving plate tectonic boundary associated with it.

The elements of an active& growing elevated mid-ocean ridge flanking abyssal hills leading down

to abyssal plain oceanic trench associated with

a subduction zone.

Active oceanic basin The Atlantic Ocean The Arctic Ocean The Pacific Ocean

Growing oceanic basin The Mediterranean Sea The Pacific Ocean

Inactive ocean basin The Gulf of Mexico in Jurassic The Aleutian Basin

Basic meteorological instruments

Sense of

human

body

1. Sight

2. Touch (feel)

3. Smell

4. Hearing

Temperature, pressure, wind measurements and humidity are the variables that are measured by: Thermometer Barometer Anemometer Hygrometer

Remote sensing Remote sensing, as used in meteorology, is the concept of

collecting data from remote weather events and subsequently producing weather information.

The common types of remote sensing are Radar, Lidar, and satellites (or photogrammetry). Each collects data about the atmosphere from a remote location and, usually, stores the data where the instrument is located. Radar and Lidar are not passive because both use EM radiation to illuminate a specific portion of the atmosphere. Weather satellites along with more general-purpose Earth-observing satellites circling the earth at various altitudes have become an indispensable tool for studying a wide range of phenomena from forest fires to El Niño.

Factors affecting shipping and transport

Weather forecasting is the application of science and technology to predict the state of the atmosphere for a future time and a given location. Human beings have attempted to predict the weather informally for millennia, and formally since at least the 19th century. Weather forecasts are made by collecting quantitative data about the current state of the atmosphere and using scientific understanding of atmospheric processes to project how the atmosphere will evolve.

Once an all-human endeavour based mainly upon changes in barometric pressure, current weather conditions, and sky condition, forecast models are now used to determine future conditions. Human input is still required to pick the best possible forecast model to base the forecast upon, which involves pattern recognition skills, teleconnections, knowledge of model performance, and knowledge of model biases. The chaotic nature of the atmosphere, the massive computational power required to solve the equations that describe the atmosphere, error involved in measuring the initial conditions, and an incomplete understanding of atmospheric processes mean that forecasts become less accurate as the difference in current time and the time for which the forecast is being made (the range of the forecast) increases. The use of ensembles and model consensus help narrow the error and pick the most likely outcome.

There are a variety of end uses to weather forecasts. Weather warnings are important forecasts because they are used to protect life and property. Temperature forecasts are used by utility companies to estimate demand over coming days. On an everyday basis, people use weather forecasts to determine what to wear on a given day. Since outdoor activities are severely curtailed by heavy rain, snow and the wind chill, forecasts can be used to plan activities around these events, and to plan ahead and survive them.

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