Thursday, January 24, 2013

surface temperature inversions

The most common manner in which surface inversions
form is through the cooling of the air near the ground at
night. Once the sun goes down, the ground loses heat
very quickly, and this cools the air that is in contact with
the ground. However, since air is a very poor conductor
of heat, the air just above the surface remains warm.

Conditions that favor the development of a strong
surface inversion are calm winds, clear skies, and long
nights. Calm winds prevent warmer air above the
surface from mixing down to the ground, and clear skies
increase the rate of cooling at the Earth’s surface.

 Long nights allow for the cooling of the ground to continue
over a longer period of time, resulting in a greater
temperature decrease at the surface. Since the nights in
the wintertime are much longer than nights during the
summertime, surface inversions are stronger and more
common during the winter months. A strong inversion
implies a substantial temperature difference exists
between the cool surface air and the warmer air aloft.

During the daylight hours, surface inversions normally
weaken and disappear as the sun warms the Earth’s
surface. However, under certain meteorological
conditions, such as strong high pressure over the area,
these inversions can persist as long as several days. In
addition, local topographical features can enhance the
formation of inversions, especially in valley locations.

Friday, January 18, 2013


One reason why scientists in general, including geomorphologists, philosophy viewed
with a jaundiced eye is that the traditional philosophy of science, particularly logical
Empiricism was highly normative or prescriptive in nature, a characteristic of many
Scientists find annoying. Nobody likes it tells how they do their work better by someone
anyone who has not actually performed the tasks involved. This problem has been accentuated by
the analytical type of logical empiricism holds that that the knowledge of the provision of
Basis for epistemic norms in science can a priori (ie, not be comprehended by empirical
Reflection on the meaning of certain phrases). In other words, the philosophical
Program to understand the science is independent of specific scientific findings, beliefs, or
The empirical basis of logical positivism clearly contrary to the empirical
modus operandi of scientists. Contemporary philosophers of science recognize fully the
need to struggle with this problem, and in the last 30 years (ie since the end of the
logical empiricism) have concentrated their efforts on the development of philosophical naturalized
Perspectives that capture the knowledge-producing potential of science as it try
actually practicing.

Monday, January 14, 2013


The layer of gases surrounding the Earth rises about 500 kilometres
above the surface, although there is no distinct boundary between
the Earth’s atmosphere and space. However, three-quarters
of the
gas in the atmosphere is within 11 kilometres of the Earth’s surface
as the density of gas is very small at high altitudes.

 This is why it
becomes more difficult to breathe when you climb mountains and
why people need oxygen masks if they are in the open air at high
altitudes. The lower layer of the atmosphere is called the troposphere
and extends to about 6 kilometres altitude over the poles
and about 15 kilometres over equatorial regions. This layer is the
one in which air mixes most rapidly and where we experience

The Earth’s atmosphere acts as a filter protecting us from space
debris and harmful radiation. The Earth receives only two-billionths
of the Sun’s total energy release but this energy is the
main driver for water, air and wind motions and most life on Earth.
It is therefore important to understand how the energy from the
Sun drives these processes. When the Sun’s energy reaches the
Earth about 6 per cent of it is scattered and returned to space by
the atmosphere, 21 per cent is scattered and reflected by clouds and
18 per cent is absorbed by the atmosphere and clouds temporarily
before being sent back out to space. Of the 55 per cent that reaches
the Earth’s surface 4 parts are reflected back to space by reflective
surfaces such as ice sheets, snow and dry, light, sandy soils, while
51 parts are absorbed by the surface.

 This means that of the total
solar energy received by the Earth, only around a half makes it all
the way down to warm the Earth’s surface. Some of this energy is
used for processes such as evaporation of water or for plant growth.
However, most absorbed radiation from the Sun (known as short-wave
radiation; an example of short-wave
radiation is visible light)
is transformed by the land, oceans and vegetation and emitted back
into the atmosphere as long-wave
radiation in the form of heat
energy (invisible infrared radiation).

 Except for the 19 per cent
of incoming solar energy that is temporarily absorbed, the atmosphere
is mostly transparent to incoming short-wave
radiation. This
means, perhaps surprisingly to many people, that the air is mainly
heated from below by long-wave
heat energy emitted by the
Earth’s surface. Thus, the atmosphere should be warmer close to
the Earth’s surface but cool with altitude in the troposphere. Since
the air is warmed by the surface below, this means that during the
day the air near the surface becomes less dense and more buoyant.
Less dense gases or liquids will naturally seek to rise and more
dense fluids will seek to fall. Hence the less dense air near the
surface seeks to rise above cooler, denser air which in turn sinks
towards the Earth’s surface. As the air rises it in turn cools because
it is able to expand due to the lower air pressure at higher altitudes.
The reason it cools is due to a fundamental law of nature which
means that as the pressure of a gas decreases the temperature will
decrease. The result of these processes is that there is large scale
vertical mixing of the air within the troposphere as rising warm air
is replaced by cooler descending air.

The atmosphere is made up of mainly nitrogen (78 per cent)
and oxygen (21 per cent). The remaining 1 per cent is made up of
mainly argon. There are also small concentrations of other gases
such as hydrogen, water vapour (the gaseous form of water),
methane, nitrous oxide, ozone and carbon dioxide. However,
despite their low concentrations some of these other gases are
important for the climate we experience. While the gases of the
atmosphere are almost unaffected by the short-wave
radiation provided
by the Sun, some of them readily absorb long-wave
produced by the Earth’s surface. Unlike oxygen and nitrogen, some
gases such as carbon dioxide, methane, water vapour and nitrous
oxide absorb the thermal energy emitted by the Earth’s surface and
provide a sort of blanket over the Earth. They radiate this energy
back down to Earth again which in turn is absorbed by the Earth
and this further enhances the heating of the atmosphere. A greenhouse
does a similar thing. The glass allows short-wave
radiation to
pass through it to the soil and plants which then absorb the radiation
and re-radiate
thermal energy back towards the glass.

However, the glass traps the long wavelength heat energy and the
warmer air inside the greenhouse. The natural greenhouse
effect in the atmosphere is a good thing. If this did not happen
then during the day the Sun’s energy would be absorbed by the
land, oceans, and vegetation at the surface and then transformed
into heat which would be radiated back into the atmosphere.
However, at night all of this energy would radiate back into space
and so the Earth’s surface temperature would fall to extremely cold
levels very quickly. The greenhouse gases prevent this from happening
by retaining some of the energy within the troposphere,
delaying its release back out to space, and keeping the planet at a
good temperature for life. The average temperature of the Earth’s
surface is 15°C but without the natural greenhouse effect the
average temperature across the Earth would be around –20°C.

The composition of the atmosphere has changed through time.
The Earth is around 4.6 billion years old. The early atmosphere
mainly consisted of nitrogen gas and carbon dioxide with no
oxygen gas. Oxygen gas did not start to appear in the atmosphere
until about 2 billion years ago. It was at this point that bacteria
evolved and they functioned by absorbing carbon dioxide from the
atmosphere and then releasing oxygen through photosynthesis.
More recently humans have also changed the composition of the
atmosphere slightly through the burning of fossil fuels and release
of other chemicals. This topic is explored further in Chapter 2.
There are many other complex feedbacks between the atmosphere
and the Earth which control climate. We will turn to some
of these in later chapters but for now a good example is the growth
of peatlands. Peat is an extremely carbon-rich
soil composed of
dead plant matter that has not fully decayed and which builds up
on the land year after year. In some places it has built up deposits
over 10 metres thick. It forms where the conditions are waterlogged
because waterlogging slows the rate of decay when plants
die. Plants take carbon out of the atmosphere to form their structure
by incorporating it into carbohydrates. Once the plants die, if


this carbon is not released again by decay, then it remains stored on
land. In fact peatlands have preserved many interesting archaeological
features including almost perfectly preserved prehistoric human
remains with their leather shoes still intact. The world’s peatlands
are a large store of carbon that was once in the atmosphere, and
they have actually reduced the amount of the greenhouse gas,
carbon dioxide. Peatlands have helped to cool the climate by a few
degrees. However, this all means that these peatlands could also be
a large potential source of carbon dioxide for the atmosphere if
they are rapidly degraded by human action such as through drainage
or extraction for horticulture or fuel.

Friday, January 11, 2013

Geography and Environment

 How do people adjust to their environment? How do people change the environment to better
suit their needs? Geographers examine where people live, why they settled there, and how they
use natural resources. For example, traveling Bushmen in Australia carry water in ostrich eggs
because water is so scarce in their environment. In other places we turn up the heat or put on a
sweater when it gets cold. All people change something about the way they live in order to adapt
to their environment.

Throughout early childhood, children become increasingly aware of how people and the Earth
interact. They know and experience how the weather and climate affect their daily lives.
Toddlers are just beginning to understand the world in which they live. Parents often try to get
them to understand what they need to do to adapt to their surroundings, like wear a jacket when it is cold, or take off their socks when it is hot outside. By ages 4 and 5, children are beginning to
learn what they can do to adjust, and they are beginning to see how people change the Earth to
their own benefit.

Toddlers think of themselves as the center of the world. The daily routines of dressing,
eating, and playing are the basis for learning how the Earth affects them, and how they
adapt to their environment.

Daily routines help toddlers make sense of their world. With routines they learn that
morning is followed by afternoon, and night follows day. As stable as their routines are,
changes will occur. These changes occur because of rain, wind, storms, or other weather
conditions. Point this out to them. ``We can't go out today because of the ice and
someone could slip, fall, and get hurt'' or ``The weather is so nice today, let's take our
lunch to the park and have a picnic.''

Add a squirt bottle of water to the sand pile so children can become aware that they have
some control over the Earth. Within limits they can adapt things to their needs. Show
them how to make sand pies by packing containers with wet sand and dumping out a sand
pie or cake. They can create mountains and then count them. Remember, they are
developing an awareness of how to control their environment.

When going through your neighborhood, name the different types of houses you find.
Distinguish between 1--story, 2--story, and multi--story houses. You might see
apartments, duplexes, townhouses, single family houses, trailers, or farm houses. When
you go on a trip, point out dwellings that are different from those in your neighborhood.

Animals need shelter too. Point out animal homes such as birds' and squirrels' nests, ant
hills, beehives, and barns.

Nearly everywhere people are building something. Stop to watch and observe how earth
is moved and buildings go up. What materials are being used? Are builders using the
stones that are found in your neighborhood, or are they making concrete out of sand and

Move the furniture around in your child's room and talk about how you are changing how
he or she uses the space.

Plant flowers in either a window box or a garden and water them together with your child.
Talk about why the plants need water. What happens if you forget to water the plants?

If you live in an urban area, try to visit a nearby farm. Some cities and states maintain
farm parks for just this purpose. Call the Department of Parks or Recreation in your area
to find one near you. Talk with your children about how farmers use natural resources—
soil, water, and sun—to grow crops and raise livestock. How do they keep livestock from
wandering off? How do they prevent crops from being eaten by birds or destroyed by

Spend the day outside with your children. If possible, go camping. It is easy to
understand why we wear long pants and shoes when there are rocks and branches on the
ground. In the woods, with no plumbing and indoor water, it will be clear why early
settlers found it so important to be near water.

Geography and Direction

Concepts of location begin early in life. By age 2, children are able to distinguish between
objects that are near and can be grasped, and those that are farther away. They can notice
features of their immediate surroundings, such as the bedroom or yard.

The idea of direction is a difficult concept. Children develop the concept of direction through
experiences such as climbing, jumping, running, and rolling around. Children need to physically
experience themselves in space.

First, children need to develop body awareness; to understand where their body is in a room, including its size and level (upright, crawling or stooping, or on the floor); how the body's different parts are put together with wriggling wrists and wobbling ankles, and how to move in directions like forward, backward, or sideways.

When they know how their body moves, they will have the basis for learning precise directions and locations later in life. The more opportunities children have to run and move about, the greater their ability tokeep track of position and location.

Children with disabilities have a special need to experience space, direction, and location. Even
when using a wheelchair, children can play simple dancing games that help them orient
themselves in space. They can take field trips into the community and use maps to follow

Geography and Location for Man

Geography and  Location

The first theme geographers use is location. This tells us exactly where in the world something
is. Just as your home has a street address, every place has a ``global address'' identified by
latitude and longitude. If you know these numbers and how to use them, you can find any place
in the world and give its absolute location.

Geographers also ask why things are located in particular places. How do these places influence
our lives?

 For example, Baltimore, Maryland, was founded at 39.3o (degrees) orth latitude and
76.6o (degrees) West longitude on an inland harbor.

It is a major shipping port for the eastern seaboard with direct land routes by train and highway to cities throughout the United States. Many people who live in Baltimore are involved in waterfront activities such as shipping, loading, and fishing.

Very young children will not be able to understand concepts like latitude and longitude, or even
left and right. However, young children learn body awareness—the shape of the body and how
much space it takes up, where the different body parts are, how the body moves and rests, how
the voice is a part of the body. This is the beginning of an understanding of location.

Young children learn that they relate to other people and physical things. To help young children
learn location, make sure they know the color and style of the building in which they live, the
name of their town, and their street address. Then, when you talk about other places, they have
something of their own with which to compare.

These themes were developed by professional geographers and are now being used in many
schools. They are:

·         Where are things located?
·         What characteristics make a place special?
·         What are the relationships among people and places?
·         What are the patterns of movement of people, products, and information?
·         How can the Earth be divided into regions for study?

Each chapter begins with some background, examples of questions geographers ask, and some
explanations of the early developmental skills that are involved. Next, there are two sets of
activities—one for children ages 2 to 3 and a second set for children ages 4 to 5. These activities
will help children gain the skills that lay the foundation for the study of geography.

Wednesday, January 9, 2013


You may be planning to go to university, or you may only be at the stage of choosing to study the subject
further within the school curriculum. Most students enjoy the scope of the material they cover in geography,

The skills you use in your geographical studies make you of potential interest to a wide range of employers.The close link between the subject and the world around us makes for a long and varied list of related careers for example working with development or aid agencies, environmental work, using Geographical Information Systems, working for the census office and in tourism and recreation.

However most of these areas involve only one part of the broad subject of geography.Statistics show that compared with other subjects, geographers are among the most employable. Many of those leaving university with a geography degree enter three fields of employment: administration and management; marketing or financial work. This is presumably because geographers possess the abilities and
skills that employers look for.

Employers want people with good communication skills – geography courses include a wide range of written and oral skills writing essays, projects and oral presentations.Employers want people who can work in a team – Fieldwork is an essential component of geography courses and is an ideal setting in which to develop teamwork and leadership skills.

Employers want people who can manage themselves – The preparation of a GCSE or A Level investigation fosters such skills.Employers want people who can analyses their work - Geographical Investigations test hypotheses and involve analysis.

Employers want people who are numerate and literate – Geographers are used to manipulating and
interpreting data and preparing reports which encourages conciseness and clarity in the use of language.
Employers want people who can ask questions and then find the answers – Geographers can pose problem sand then investigate the answers. They can undertake complex decision making exercises using informational a variety of scales.

Employers want people who are computer literate – Geographers use ITC in many aspects of their work, for data collection, through the Internet, analysis spreadsheets, all vital skills, especially in a commercial
business environment.Employers want people who are spatially aware – Geographers use maps all the time.