EARTHSONG

Do you know that our planet Earth also sings (EarthSong) which is tagged ‘Chorus’. In space, it is believed that no one can hear you when you scream.

Nobody ever said anything about singing, though. A NASA (National Aeronautics Space Administration) spacecraft has beamed back a beautiful song sung by our very own planet.

“It is called Chorus, explains Craig Kletzing of the University of Iowa”. “This is one of the clearest examples we’ve ever heard”. A ScienceCast video explores the eerie-sounding radio emissions that come from our planet (watch video at: Sciencecast video).

Chorus is an electromagnetic phenomenon caused by plasma waves in the Earth’s radiation belts. For years, ham radio operators on Earth have been listening to this sound from afar. Now, NASA’s twin ‘Radiation Belt Storm Probes’ are travelling through the region of space where chorus actually comes from – and the recording are out of this world.

“This is what the radiation belt would sound like to a human being if we had radio antennas for ears” says Kletzing, whose team at the University of Iowa built the ‘EMFISIS’ (Electronic and Magnetic Field Instrument Suite and Integrated Science) receiver used to pick up the signals.

 

Chorus is not an acoustic wave of the kind that travels through the air of our planet. Chorus is made of radio waves that oscillate at acoustic frequencies between 0 and 10 kHz. The magnetic search coil antennas of the Radiation Belt Storm Probes are designed to detect these kinds of waves.

Chorus emissions are front and centre for the Storm Probe Mission. They are thought to be one of the most important waves for energizing electrons that make up the outer radiation belt. In particular, Chorus might be responsible for the so-called ‘killer electrons’, high-energy particles that cans endanger both satellites and astronauts.

Many electrons in the radiation belts are harmless, with too little energy to do damage to human or electronic systems. But, sometimes, these electrons can catch a Chorus wave, like a surfer riding a wave on Earth and gain enough energy to become dangerous – or so researchers thinks.


 

Is Geography Dead or Alive?

Geography was first coined by Greek scholar, Eratosthenes. He invented the discipline of geography, including the terminology used today.

Although, Chinese Geographical writings are considered the first predecessors, followed and developed during the Greek and Roman times. Pilgrimages, travels for trade and the discovery of new lands contributed significantly to the geographical knowledge, as it did the astronomical discoveries. The Germans, Humboldt and Ritter are considered ‘Fathers of modern Geography’, the first on the line of physical geography and the second on the human aspects. After them and up to the present, new directions have developed within geography, mainly due to the introduction of quantitative and technical tools and to the recent globalization.

Geography as a discipline has evolved over the course of time. And it has like other subjects passed from descriptive to the model-making stage. The Geographical Evolution started in the 19^th century and got accelerated during the mid-20^th century until the present century.

It is worthy to note that, the discipline of geography right from the onset has always sought to study the earth, its shape, its various processes as well as it formation. And it also seeks to study the relationship of man (human beings) with this (natural) environment as well as the cultural environment.

During the first 50 years of the 1900s, many academics in the field of geography extended the various ideas presented in the previous century to studies of small regions all over the world. Most of these studies used descriptive field methods to test research questions. Starting in about 1950, geographic research experienced a shift in methodology. Geographers began adopting a more scientific approach that relied on quantitative techniques. The quantitative revolution was also associated with a change in the way in which geographers studied the Earth and its phenomena. Geographers now began investigating process rather than mere description of the event of interest. Today, the quantitative approach is becoming even more prevalent due to advances in computer and software technologies.

In 1964, William Pattison suggested that modern Geography was now composed of the following four academic traditions:

Spatial Tradition - the investigation of the phenomena of geography from a strictly spatial perspective.

Area Studies Tradition - the geographical study of an area on the Earth at either the local, regional, or global scale.

Human-Land Tradition - the geographical study of human interactions with the environment.

Earth Science Tradition - the study of natural phenomena from a spatial perspective. This tradition is best described as theoretical physical geography.

Today, the academic traditions described by Pattison are still dominant fields of geographical investigation.

All the above attest to the fact that Geography has never for once died since its inception as a field of study, rather it has only undergone several revolution/changes over the years.

Conclusively, it can be stated that Geography as a discipline can never die. And this is largely due to the fact that it studies a constantly living and working system. This therefore imply that the existence of the environment (earth system) is a function of the existence of the field of Geography.

Weather is the state of the atmosphere, to the degree that it is hot or cold, wet or dry, calm or stormy, clear or cloudy. Most weather phenomena occur in the troposphere, just below the stratosphere. Weather generally refers to day-to-day temperature and precipitation activity, whereas climate is the term for the average atmospheric conditions over longer periods of time. When used without qualification, "weather" is understood to mean the weather of Earth.
Weather is driven by air pressure (temperature and moisture) differences between one place and another. These pressure and temperature differences can occur due to the sun angle at any particular spot, which varies by latitude from the tropics. The strong temperature contrast between polar and tropical air gives rise to the jet stream. Weather systems in the mid-latitudes, such as extra-tropical cyclones, are caused by instabilities of the jet stream flow. Because the Earth's axis is tilted relative to its orbital plane, sunlight is incident at different angles at different times of the year. On Earth's surface, temperatures usually range ±40 °C (−40 °F to 100 °F) annually. Over thousands of years, changes in Earth's orbit affect the amount and distribution of solar energy received by the Earth and influence long-term climate and global climate change.
Surface temperature differences in turn cause pressure differences. Higher altitudes are cooler than lower altitudes due to differences in compressional heating. Weather forecasting is the application of science and technology to predict the state of the atmosphere for a future time and a given location. The atmosphere is a chaotic system, so small changes to one part of the system can grow to have large effects on the system as a whole. Human attempts to control the weather have occurred throughout human history, and there is evidence that human activity such as agriculture and industry has inadvertently modified weather patterns.

There are two reasons why tropical weather is different from that at higher latitudes. The sun shines more directly on the tropics than on higher latitudes (at least in the average over a year), which makes the tropics warm. And, the vertical direction (up, as one stands on the Earth's surface) is perpendicular to the Earth's axis of rotation at the equator, while the axis of rotation and the vertical are the same at the pole; this causes the Earth's rotation to influence the atmospheric circulation more strongly at high latitudes than low. Because of these two factors, clouds and rain storms in the tropics can occur more spontaneously compared to those at higher latitudes, where they are more tightly controlled by larger-scale forces in the atmosphere. Because of these differences, clouds and rain are more difficult to forecast in the tropics than at higher latitudes. On the other hand, temperature is easily forecast in the tropics, because it doesn't change much.
Weather originating in the tropics is considered tropical weather. The tropics is a region of the Earth surrounding the Equator. It is limited in latitude by the Tropic of Cancer in the northern hemisphere at approximately 23° 26′ 16″ (or 23.4378°) N and the Tropic of Capricorn in the southern hemisphere at 23° 26′ 16″ (or 23.4378°) S; these latitudes correspond to the axial tilt of the Earth. The tropics are also referred to as the Tropical Zone and the Torrid Zone. The tropics include all the areas on the Earth where the Sun reaches a point directly overhead at least once during the solar year.
The tropics are distinguished from the other climatic regions of Earth: the middle latitudes and the Polar Regions on either side of the equatorial zone. There are two significant factors that make tropical weather different from that of the middle latitudes and the Polar Regions.  The obvious fact is that more solar energy reaches the tropical region. Also the Coriolis forces is much weaker, especially near the equator which makes it harder to form organized circulation in the tropical regions equator-ward of 10 degrees of North and south latitude.