Meteorology and Physics in Byzantium

The earth is surrounded by a large envelope of gases called atmosphere. The condition of the atmosphere and the changes it undergoes influence all physical, chemical and biological activities over the earth. The study pertaining to lower atmosphere and its changes is called atmosphere physics or meteorology. In modern usage, meteorology denotes the science of weather and includes the study of atmospheric phenomena. Definition Meteorology can be defined as the science that deals with the study of the atmosphere. The temperature at the tropopause is of the order of-80˚C over the equator and around-56˚C over the poles. The height as well as temperature of the tropopause varies with the seasons and weather situation, the lowest values occurring during the winter. The tropopause is not a continuous surface. There are breaks separating polar, extra-tropical (middle) and tropical tropopauses, sometimes one overlapping the other. These breaks facilitate the exchange of air between the tropopause and the region above. Inversions and isothermal layers can be seen in the troposphere. Nearly 75 percent of the mass of the atmosphere is in the troposphere. 1.3.2. Stratosphere Above the troposphere is an isothermal layer followed by a region of inversion extending upto nearly 50km. This is termed as the stratosphere. Temperatures increase from around 20km becoming roughly 0˚C by about 50km, which is stratopause. This rise in temperature is due to the absorption of ultraviolet radiation in the ozone layer between, say, 20 and 50km. This region sometimes gets rapidly warmed, mainly in the higher latitudes, at times by as much as 30 to 40˚C in a matter of a few days. This phenomenon is termed explosive warming of the stratosphere. 1.3.3. Mesosphere Above the stratosphere is the mesosphere extending from roughly 50 to 80km. The temperature in this region once again decreases with altitude, lowering to about-95˚C at the mesopause around 80km. 1.3.4. Thermosphere Temperatures rise rapidly above the mesopause, reaching nearly 1000˚C by about 300km. This region is known as the thermosphere. 1.3.5. Exosphere The lighter gases, hydrogen and helium, slowly become free of the earth's gravitational field and escape to space by about 600km. This region has been named as the exosphere, which gradually merges into the interplanetary space. 1.4.Composition of atmosphere 1.4.1.Gases The atmosphere we live in is a mixture of gases composed mainly of nitrogen and oxygen. The proportion of the various gases in the atmosphere by volume is 78 percent nitrogen, 21 percent oxygen and the rest 1 percent made up of small amounts of argon, carbon dioxide, neon, helium, krypton, xenon, hydrogen and traces of ozone, methane, sulphur dioxide, nitrogen oxides etc. The atmospheric gases are held on to the earth by the pull of gravitation. Each constituent has its own role to play in sustaining life on earth. Oxygen is essential for us to live and for combustion to take place. The role of nitrogen is also important. We cannot breathe pure oxygen. Nitrogen slows down the burning process. Carbon dioxide constitutes 0.03 percent and provides food for plants through photosynthesis, which replenishes oxygen. Ozone is found mostly between 20 and 50km with the maximum concentration around 25km amsl. It absorbs the ultraviolet radiation from the sun and thus filters the injurious radiation from harming us. Carbon dioxide and water vapour absorb the infrared radiation emanating from the earth and prevent excessive radiational cooling. The atmosphere acts as a protective cover to the earth by regulating the heat flow. 1.4.2. Water vapour Water vapour is present in varying proportions. This composition remains more or less constant upto a height of 80km. The moisture content in the atmosphere varies depending on the latitude, temperature, wind and atmospheric systems. Water can be present in the vapour, liquid or solid phase, sometimes as much as 4 percent. Water and its change of phase are important in the occurrence of weather phenomena. Water vapour decreases as altitude increases. 1.4.3. Aerosols Atmospheric aerosols are a suspension of fine solid and liquid particles in the atmosphere. These clouds of suspended matter range from dust and smoke to mists, smogs and haze. They are not always the result of pollution from human activities; some enters the atmosphere from volcanic eruptions or dust storms. Some aerosols particles are invisible to the human eyes because they are smaller than the wavelength of light.

2001

Nature Reviews Earth & Environment

For tens of thousands of years, indigenous cultures around the world have recognized cycles and systems in the environment, and that humans are an integral part of these. However, it was only in the early 20th century that contemporary systems thinking was applied to the Earth, initiating the emergence of Earth System Science (ESS). Building on the recognition that life exerts a strong influence on the Earth's chemical and physical environment, ESS originated in a Cold War context with the rise of environmental and complex system sciences 1-3. The ESS framework has since become a powerful tool for understanding how Earth operates as a single, complex, adaptive system, driven by the diverse interactions between energy, matter and organisms. In particular, it connects traditional disciplines-which typically examine components in isolation-to build a unified understanding of the Earth. With human activities increasingly destabilizing the system over the last two centuries, this perspective is necessary for studying global changes and their planetary-level impacts and risks, including phenomena science in the 1980s, global expansion in the 1990s and present-day ESS. A timeline of key events, publications and organizations that characterize the evolution of ESS is shown in Fig. 1. Beginnings (pre-1970s). Past conceptualizations of the Earth formed important precursors to the contemporary understanding of the Earth System. Examples include J. Hutton's 1788 'theory of the Earth' , Humboldtian science in the 19th century and V. Vernadsky's 1926 'The Biosphere' 7. Understanding the historical roots of ESS, however, requires a focus on the second half of the 20th century when, in a Cold War context, important shifts occurred in the Earth and environmental sciences 8. Thanks to military patronage taking precedence over traditional sources of funding for Earth sciences, geophysics experienced unprecedented growth 9. Moreover, surveying and monitoring the global environment became a strategic imperative, providing information that would later be useful for contemporary ESS 10,11. In the middle of the 20th century, international science started to develop, epitomized by the International Geophysical Year (IGY) 1957-1958 (reF. 12). This unprecedented research campaign coordinated the efforts of 67 countries to obtain a more integrated understanding of the geosphere, particularly glaciology, oceanography and meteorology. One of the key impacts of the IGY was a lasting transformation in the practices used to understand how the Earth works. The interpretative and qualitative geological and climatological research based on field observations-as classically studied by geographers-was replaced by field instrumentation, continuous and quantitative monitoring of multiple variables and numerical models 13. This transformation led to the two contemporary paradigms that structure the Earth sciences: modern climatology and plate tectonics 14,15. Ecology and environmental sciences also developed rapidly 16. Ecosystem ecology emerged with the work of G. E. Hutchinson and the brothers H. Odum and E. Odum, supported by the Scientific Committee on Problems of the Environment (SCOPE).

Earth science is the name for the group of sciences that deals with Earth and its neighbors in space.

Bulletin of the American Meteorological Society, 2017

The exigencies of the global community toward Earth system science will increase in the future as the human population, economies, and the human footprint on the planet continue to grow. This growth, combined with intensifying urbanization, will inevitably exert increasing pressure on all ecosystem services. A unified interdisciplinary approach to Earth system science is required that can address this challenge, integrate technical demands and long-term visions, and reconcile user demands with scientific feasibility. Together with the research arms of the World Meteorological Organization, the Young Earth System Scientists community has gathered early-career scientists from around the world to initiate a discussion about frontiers of Earth system science. To provide optimal information for society, Earth system science has to provide a comprehensive understanding of the physical processes that drive the Earth system and anthropogenic influences. This understanding will be reflected ...

The Scientific World JOURNAL, 2001

There is a satisfying logic to the Greek choice of air, water, and earth as elements. Today we see this logic reflected in the way that that global science is subdivided into the categories of air, land, and water. Thus, the relevance of a science of global issues is not merely of academic interest. The tide of environmental concern, a vision of limits to growth, and a desire for sustainability have fostered an unprecedented interest in global sciences.

2021

This course will introduce basic principles of the physical sciences, including fundamental topics in physics, astronomy, and Earth sciences. A major focus of the course will be on building confidence in science, inspiring scientific curiosity, and preparing students to incorporate current science education standards in their future K-8 classrooms. Specific topics that we will explore include the scientific method, the physics of motion, force, and energy. We will also cover the four main components of the Earth system, the history and evolution of the Earth as a planet, the ways in which humans use resources and affect our planet, and our planet's place in the Solar System and Universe.

Philosophies of the Sciences, 2010

This essay presents a philosophical analysis of earth science, a discipline which has received relatively little attention from philosophers of science. We focus on the question of whether earth science can be reduced to allegedly more fundamental sciences, such as chemistry or physics.